HK1159809A - Accessory for a portable computing device - Google Patents

Description

Accessory for portable computing device

Technical Field

The present invention relates generally to portable computing devices, and more particularly to accessories for portable computing devices.

This application claims priority from U.S. provisional patent application No.61/292,640 entitled "Keyboard Dock for a Portable Computer Device," filed on 6.1.2010, the entire contents of which are incorporated herein by reference for all purposes.

Background

Computing devices (e.g., personal computers) have been in use for decades. Computing devices are used to perform a variety of tasks, from simple to some of the most complex. Computing devices may be broadly classified as portable (e.g., laptop PCs or PDAs) and non-portable (e.g., desktop PCs).

In the past decade, portable computing devices have become popular because of their portability and ability to manage multiple tasks. For example, portable computing devices (e.g., personal digital assistants) can provide the ability to check and respond to e-mail, manage meetings, display graphics and video, and play music. Most portable electronic devices in use today have no keyboard or a small and inconvenient keyboard. In addition, integrated keyboards are often less functional than traditional keyboards.

The portable computing device may include one or more connectors or ports that may be used to interface with other devices. For example, a connector or port may enable a portable computing device to be inserted into a docking system or to receive an accessory device.

Disclosure of Invention

Certain embodiments of the invention include an accessory for a portable computing device. The accessory may include a connector interface for connecting with a portable computing device and an additional connector interface for connecting with another accessory that may be used with the portable computing device. In some embodiments, the accessory may include a metal body (metal mass) that may provide stability to the accessory and may also provide a ground path to the accessory and associated circuitry.

In some embodiments, the accessory may be configured to operate at multiple voltage levels. In this case, when an additional accessory is connected to the portable computing device via the accessory, the accessory may operate at the same voltage level as the additional accessory even if the normal operating voltage of the accessory is different from the operating voltage of the additional accessory.

In some embodiments, the accessory may communicate with the portable computing device using a portable computing device-specific protocol. Key press events (e.g., USB HID events) generated by the keyboard may be encapsulated with the portable computing device specific protocol to generate portable computing device specific protocol packets. The portable computing device specific protocol packet containing the key press event may be transmitted to the portable computing device for interpretation. A key press (HID) event generated by a keyboard contained in the accessory may be contained as a payload of a portable computing device specific protocol command and sent to the portable computing device. The portable computing device can parse the command and send one or more HID events received from the accessory to the HID layer within its USB stack for interpretation and processing.

The following detailed description and the accompanying drawings provide a better understanding of the nature and advantages of the present invention.

Drawings

FIG. 1A is a front view of a keyboard accessory according to an embodiment of the present invention.

FIG. 1B is a side view of a keyboard accessory according to an embodiment of the present invention.

FIG. 1C is a bottom view of a keyboard accessory according to an embodiment of the present invention.

FIG. 1D is a cross-sectional view of a keyboard accessory according to an embodiment of the present invention.

FIG. 2A is a front view of a portable computing device according to an embodiment of the present invention.

FIG. 2B is a side view illustrating a portable computing device coupled to a keyboard accessory according to an embodiment of the present invention.

FIG. 3 is a block diagram of a portable computing device according to an embodiment of the present invention.

FIG. 4 is a block diagram of a keyboard accessory according to an embodiment of the present invention.

FIG. 5 is a table illustrating commands that may be used to communicate key press events between a keyboard accessory and a portable computing device according to embodiments of the present invention.

FIG. 6 is a functional block diagram of a software stack included in a portable computing device according to an embodiment of the present invention.

FIG. 7 is a process flow diagram for processing portable computing device accessory protocol packets in accordance with an embodiment of the present invention.

FIG. 8 is a process flow diagram for communicating instructions between a keyboard accessory and a portable computing device according to an embodiment of the present invention.

Detailed Description

Certain embodiments of the present invention provide an accessory for a portable computing device. The accessories may include various types of user input devices such as a touch screen, touch pad, scroll wheel, click wheel, dials, buttons, keypad, microphone, and the like. Although some embodiments are described below with specific reference to a keyboard as the user input device, those skilled in the art who have the benefit of this disclosure will appreciate that any user input device(s) may be incorporated into the accessory without departing from the spirit and scope of the claims, and that some accessories need not provide a user input device at all.

Certain embodiments of the invention relate to an accessory for a Portable Computing Device (PCD). The accessory can provide an interface for connecting to a portable computing device. In some embodiments, the accessory may include an additional interface to connect the additional accessory to the portable computing device through the accessory.

In some embodiments, an accessory may provide low loss signal passing capability, where the accessory may be transparent to other accessories connected to the portable computing device through the accessory. In some embodiments, the accessory may include a metal body that may provide stability and support to the accessory and may additionally provide a ground path to electronics contained in the accessory.

Fig. 1A illustrates a perspective view of a keyboard accessory 100 according to an embodiment of the present invention. Keyboard accessory 100 may include a keyboard 110 and a base (pedestal) 120. The base 120 may include a Portable Computing Device (PCD) interface connector 130 that may be used to connect a PCD (not shown) to the keyboard base 120. The base 120 may house control circuitry and other electronics to manage communications between the keyboard accessory 100, the PCD, and any other accessory coupled to the PCD. The base 120 may also include accessory ports for connecting additional accessories to the PCD (not shown in fig. 1A). Supporting electronics for communicating with and managing other accessories may be housed within the base 120. In some embodiments, the base 120 may be designed as a housing and may be made of various materials, including metal and/or plastic. The keyboard 110 may be similar to any standard keyboard currently available, or may be a custom keyboard configured to be usable with a PCD. The keyboard 110 may include a keypad 113 that may include, for example, a standard QWERTY keypad, a numeric keypad, or the like. Keyboard accessory 100 may be designed to work with a variety of PCDs, such as personal digital assistants, computers without keyboards, and the like. In some embodiments, the orientation of the keyboard 110 may be at an angle between 4 ° and 9 ° relative to the top surface of the base 120.

FIG. 1B illustrates a side view of the keyboard accessory 100, according to an embodiment of the present invention. As described above, the base 120 may include an accessory port 140 that may be used to connect additional accessories to the PCD through the keyboard accessory. In some embodiments, the accessory port 140 may be located on the rear side of the base 120. The accessory port 140 may be used to connect additional accessories (e.g., a GPS receiver or power supply) to the PCD via the keyboard accessory. The accessory port 140 can include a port compatible with the iPod manufactured by Apple incAnd iPhoneThe connectors used in the product are similar to the 30 pin connectors. In some embodiments, the center-to-center distance between the PCD connector interface 130 and the accessory port 140 may be between 40mm and 70 mm. In some embodiments, the base 120 may have a support structure 150 attached to a lower surface of the base. The support structure 150 may extend horizontally along the width of the base 120 and may be positioned along the lower edge 180 furthest from the keyboard. The support structure 150 may vertically protrude downward from the lower surface of the base 120 to a predetermined distance. In some embodiments, this predetermined distance may be between 1mm and 2 mm. In some embodiments, the length of the support structure 150 may be between 120mm and 140mm, and the width of the support structure 150 may be between 55mm and 80 mm. In some embodiments, there may be no support structure along the lower edge 190 of the base 120 closest to the keyboard 110. In some embodiments, the base 120 may also include a PCD support plate 127. The PCD support plate 127 may be used to support a PCD when the PCD is connected to a keyboard accessory. The PCD support plate 127 mayPositioned such that the rear side of the PCD is in contact with the PCD support plate 127 when the PCD is connected to the keyboard accessory. In some embodiments, the PCD support plate 127 may be oriented vertically with respect to the top surface of the base 120. In some embodiments, the PCD support plate 127 may be oriented at an angle between 15 ° and 35 ° relative to a surface perpendicular to the top surface of the base 120. In some embodiments, the PCD support plate 127 may be raised from the top surface of the base 120 by a height of between 25mm and 35 mm. In some embodiments, the support structure 150 may be formed in a strip shape and may extend along the entire width of the base 120 as described below with reference to fig. 1C.

The PCD interface connector 130 may be used to interface with a PCD. In some embodiments, the PCD interface connector 130 may be rotatable or movable along multiple axes to facilitate connection and disconnection with a PCD, and/or to enable a range of rest angles (rest angles) for a PCD when docked. Details of a PCD interface connector are described in co-pending U.S. patent application No.12/652,018, filed 1, 4, 2010. The keyboard 110 may be attached at one end 111 to a top edge 115 of the base 120 and may extend forward and downward from the edge 115. Keyboard 110 may have one or more support feet 160 attached to the lower surface near its other end 112 that is not connected to edge 115. In some embodiments, the diameter of each support foot 160 may be between 7mm and 9 mm. In some embodiments, a pair of support feet 160 may be located at each corner of the tip 112 and may have a center-to-center distance between 240mm and 270 mm. The support feet 160 may extend vertically downward from the lower surface of the keyboard 110 to a predetermined distance. In some embodiments, this predetermined distance may be between 1mm and 2 mm. In some embodiments, when the keyboard accessory 110 is placed on the surface 125 (dashed lines), the support feet 160 of the keyboard and the support structure 150 of the base may simultaneously contact the surface 125, thereby providing a stable environment for using the keyboard 110 and maintaining the lower surface of the base 120 above the surface. In particular, a region 126 near the lower surface of the base 120 is held away from the surface 125. In this way, stability of the entire keyboard accessory 100 may be achieved with only three-point support (i.e., support structure 150 and two support feet 160).

FIG. 1C illustrates a bottom view of keyboard accessory 100 illustrating support structure 150 and support feet 160, in accordance with an embodiment of the present invention. As shown in fig. 1C, a support structure 150 may be attached to the lower surface of the base 120. In one embodiment, the support structure 150 may extend along a lower edge 180 of the base 120. Those skilled in the art will appreciate that the shape and size of the support structure 150 is not limited to that shown in FIG. 1C. The support feet 160 may be attached to the lower surface of the keyboard 110 at two corners. One skilled in the art will appreciate that support feet 160 may be located at other positions along the lower surface of keyboard 110. This arrangement of support feet 160 and support structure 150 provides a stable three-point support on a flat or substantially flat surface, which may reduce or eliminate rocking or other movement of keyboard 110 during use. In addition, depending on the height of the support feet, an interesting visual perception can be created in region 126 (shown in FIG. 1A): this area appears to be touching the surface and is not actually present.

FIG. 1D illustrates a cross-sectional view of the keyboard accessory 100, in accordance with an embodiment of the present invention. FIG. 1D illustrates a slightly enlarged cross-section of the base to properly show the details of the interior of the base. As shown in FIG. 1D, the keyboard 110 may include a keyboard control panel 116 that is capable of supporting the keypad 113 and managing keyboard functions. The keyboard control board 116 may include a keyboard controller (not shown) and associated circuitry to convert key press events into appropriate signals to send to the PCD connected to the keyboard accessory 100. In some embodiments, the base 120 may include an accessory control panel 121 that can control the overall operation of the keyboard accessory 110. The accessory control board 121 may be a printed circuit board that supports a microprocessor or microcontroller, memory devices, and interconnects for exchanging signals with the interface connectors 130 and 140. In some embodiments, the keypad 110 can be connected to the metal block 170 via connection path 135 and to the accessory control board 121 via connection path 136. PCD interface connector 130 may be connected to metal block 170 via connection path 131 and to accessory control board 121 via connection path 132. The accessory port 140 can be connected to the metal block 170 via a connection path 141 and to the accessory control board 121 via a connection path 142. The accessory control board 121 can be connected to the metal block 170 through the connection path 122.

In some embodiments, the base 120 may include a metal body 170. The metal body 170 may provide stability and support to the keyboard accessory 100. In some embodiments, the metal body 170 may consist essentially of zinc. In other embodiments, the metal body 170 may comprise copper, aluminum, steel, or combinations thereof. In some embodiments, the metal body 170 may have a length between 125mm and 145mm, a width between 65mm and 75mm, and a thickness (height) between 36mm and 50 mm. In some embodiments, the shape of the metal body 170 may be a block (e.g., a rectangular parallelepiped) or any other shape desired. In some embodiments, metal body 170 occupies between 45% and 55% of the volume of base 120, and may weigh between 130 grams and 145 grams, while the total weight of keyboard accessory 100 may be between 550 grams and 650 grams.

In some embodiments, in addition to providing stability and support to the keyboard accessory 100, the metal body 170 may provide a ground path for various electronic components of the keyboard accessory 100. For example, the keyboard control board 116, the accessory control board 121, the PCD interface connector 130, and the accessory port 140 may all be coupled to the metal body 170, and the metal body 170 may provide a ground path for all of these components.

As described above, the PCD may be connected to the keyboard accessory 100 via the PCD interface connector 130. A PCD may be any device capable of performing calculations, playing video or music, connecting to the internet and having browsing capabilities, etc. FIG. 2A illustrates a Portable Computing Device (PCD) in accordance with an embodiment of the present invention. PCD 200 may include a display 210, one or more input devices 220, and an accessory I/O interface 230.

The display 210 may be a touch screen in some embodiments and may be capable of displaying graphics and other information at various resolutions. In some embodiments, the display 210 may be operated by a stylus or by contact of a user.

User input device 220 may be used to provide input to PCD 200. The input may be in the form of a selection of an option provided on the display 210, a click of a button on the display 210, or the like. In some embodiments, the user input devices 220 can be discrete buttons that can be individually operated to provide input to the PCD 200. In other embodiments, the user input device 220 may be implemented in the form of an icon displayed on the display 210. The user may activate these icons to control the functions of the PCD 200.

The accessory I/O interface 230 can be used to connect the PCD 200 to a keyboard accessory or any other accessory. In some embodiments, accessory I/O interface 230 may be compatible with the iPod manufactured and sold by Apple IncThe connectors used on the product correspond to 30 pin connectors. Alternatively or additionally, accessory I/O interface 230 can include other connectors and/or wireless interfaces (e.g., bluetooth, etc.). In some embodiments, accessory I/O interface 230 can include more than one connector.

FIG. 2B illustrates PCD 200 connected to keyboard accessory 100 through PCD interface 130 and accessory I/O interface 230. Upon connection, PCD 200 is able to identify keyboard accessory 100, which the user may begin using. In some embodiments, the PCD may be located in one of a plurality of locations supported by the rotatable PCD interface connector 130. In some embodiments, PCD 200 may be connected to and disconnected from keyboard accessory 100 with only one hand, without having to hold keyboard accessory 100 during the connection or disconnection process.

FIG. 3 is a block diagram of a PCD300 (e.g., implementing the PCD 200 of FIG. 2A) in accordance with an embodiment of the present invention. PCD300 may include a processor 302, a storage device 304, a user interface 306, an accessory input/output (I/O) interface 308, and a network interface 310.

The processor 302 may be implemented in the form of one or more integrated circuits (e.g., a conventional microprocessor or microcontroller) that may control the operation of the PCD 300. For example, processor 302 can communicate with an accessory connected via accessory I/O interface 308 in response to user input signals provided by user interface 306. In some embodiments, processor 302 may communicate directly with an accessory connected to accessory port 140 of keyboard accessory 100.

The storage device 304 may be implemented, for example, with a disk, flash memory, or any other non-volatile storage medium. In some embodiments, the storage device 304 may store documents, graphics, media assets (assets), and the like, which can be manipulated by the PCD 300. The storage device 304 may also store information related to various accessories that can be used with the PCD 300. The storage device 304 may also store other information, such as scheduled appointments and events, notes, and/or other personal information. In some embodiments, storage device 304 may store one or more programs (e.g., video game programs, personal information management programs, image processing applications, media playback programs, word processing programs, presentation applications, etc.) to be executed by processor 302.

The user interface 306 may include input controls such as a touch screen, touch pad, scroll wheel, click wheel, dial, buttons, keypad, microphone, and the like. The user interface 306 may also include one or more user output devices such as indicator lights, speakers, headphone jacks, and the like, as well as supporting electronics (e.g., analog-to-digital or digital-to-analog converters, signal processors, and the like). A user can operate various input controls of the user input interface 306 to invoke functionality of the PCD300 and to be able to view and/or hear output from the PCD 300.

Accessory I/O interface 308 can enable PCD300 to communicate with various accessories (e.g., keyboard accessory 100). For example, accessory I/O interface 308 can support connections to remote control units, external speaker accessories, external video devices, and the like. In some embodiments, various accessories may be connected to the keyboard accessory 100, and the PCD300 may communicate directly with these connected accessories. In some embodiments, accessory I/O interface 308 comprises a connection to an iPod manufactured and sold by Apple IncThe connectors used on the product are similar to the 30 pin connectors. Alternatively or additionally, accessory I/O interface 308 can include other connectors and/or wireless interfaces (e.g., bluetooth, etc.). In some embodiments, accessory I/O interface 308 can include more than one connector.

Network interface 310 may enable PCD300 to communicate with and exchange information with other devices on a network. In some embodiments, the network interface 310 may include a Radio Frequency (RF) transceiver component (e.g., using cellular telephone technology, advanced data network technologies (e.g., 3G or EDGE), WiFi (IEEE 802.11 family standards), or other mobile communications technologies, or any combination thereof), a GPS receiver component, and/or other components for accessing wireless voice and/or data networks. In some embodiments, the network interface 310 may provide wired network connection capabilities (e.g., Ethernet) in addition to, or instead of, a wireless interface. The network interface 310 may be implemented with a combination of hardware (e.g., antennas, modulators/demodulators, encoders/decoders, and other analog and/or digital signal processing circuitry) and software components.

In some embodiments, the PCD300 may provide power to a keyboard accessory and to any other accessory connected to the keyboard accessory. The accessory I/O interface 308 may be used to route (route) power.

Fig. 4 is a block diagram of a keyboard accessory 400 according to an embodiment of the present invention. Keyboard accessory 400 may include a controller 402, a keypad 404, a PCD interface 406, one or more pointer devices 408, a memory 410, and an accessory interface 412.

Controller 402 may be implemented in the form of one or more integrated circuits (e.g., a conventional microprocessor or microcontroller) that may control the operation of keyboard accessory 400. For example, controller 402 can manage communication between keyboard accessory 400 and a PCD connected to the keyboard accessory via PCD interface 406. In some embodiments, controller 402 can also manage communication between keyboard accessory 400 and other accessories coupled to the keyboard accessory via accessory interface 412. In some embodiments, controller 402 may be part of a control circuit designed to control the operation of a keyboard accessory.

Keypad 404 may be similar to any conventional keypad available in the market. Each key in the keypad corresponds to a character or a designated function. When a particular key is depressed, the controller 402 located in the keyboard may sense such key depression and may generate a key depression event signal corresponding to the depressed key. Controller 402 may then send the key press event signal to processor 302 of PCD300 via PCD interface 406 and accessory interface 308. The processor 302 can receive the signal bits corresponding to the key press event and can decode them into the appropriate key press. The PCD may then decide what action to perform, such as displaying a character on the screen or performing some action, depending on the key that was pressed. When the key is released, a stop code may be sent to the PCD to indicate that the previously depressed key is no longer being depressed. In some embodiments, a PCD connected to the keyboard accessory 400 may be awakened from its sleep state by depressing a key on the keypad 404. An example of this characteristic is described in co-pending U.S. provisional patent application No.61/292,626, filed on 6/1/2010.

PCD interface 406 may enable keyboard accessory 400 to communicate with a PCD. As described above, a PCD may be a media player, a personal digital assistant, a portable computer, and the like. In some embodiments, the PCD interface 406 may comprise a standard interface with an iPod manufactured and sold by Apple IncThe connectors used on the product are complementary 30 pin connectors. Alternatively or additionally, PCD interface 406 may include other connectors and/or wireless interfaces (e.g., bluetooth, etc.). In some embodiments, the PCD interface 406 may include more than one connector. In some embodiments, PCD interface 406 may press from keypad 404The key depression event is communicated to the PCD and commands/signals from the PCD are communicated to the keyboard accessory 400.

The indicator device 408 may include one or more illumination devices, such as Light Emitting Diodes (LEDs), or an audible device. The indicator device 408 may communicate status information related to the keyboard accessory to the user in a visual or audible manner. For example, the indicator device 408 may include an LED to indicate PCD connection status. In some embodiments, the LED may be illuminated whenever the PCD is connected to and provides power to the keyboard accessory. In some embodiments, the indicator 408 may communicate the status of the accessory, the status of certain key adjusters (e.g., CAPSlock, Numlock, etc.), and other events. In some embodiments, the indicator device 408 may also include a textual indicator that expresses a particular state. For example, when the PCD is connected to a keyboard accessory. An indicator showing "PCD connected" may light up to provide information to the user that the PCD is connected and operational. In some embodiments, the indicator device 408 may also include a speaker to deliver audio (e.g., beeps, speech, etc.) to indicate the status of the keyboard accessory and/or PCD. In some embodiments, the indicator device 408 may also provide an audio output from a signal received from the PCD.

The memory 410 may be implemented, for example, with a disk, flash memory, or any other non-volatile storage medium. In some embodiments, memory 410 may store firmware for a keyboard accessory. In some embodiments, the memory 410 may store information about various accessories that can be connected to the PCD via a keyboard accessory. In this case, when an accessory is connected to the keyboard accessory via the accessory interface 412, the keyboard accessory can determine which accessory is connected based on the particular signals and information provided by the accessory. Depending on the accessory connected, the keyboard accessory may change its own configuration to be able to work in conjunction with the accessory. In some embodiments, memory 410 may store information related to one or more PCDs. For example, when a particular PCD is connected, the keyboard accessory may determine the type of PCD (e.g., whether the media player or portable computer) and automatically operate in a configuration compatible with the PCD.

Accessory interface 412 may enable an accessory to connect to keyboard accessory 400. In some embodiments, accessory interface 412 may include a connection to an iPod manufactured and sold by Apple incThe connectors used on the product correspond to 30 pin connectors. Alternatively or additionally, the accessory interface 412 can include other connectors and/or wireless interfaces (e.g., bluetooth, etc.). In some embodiments, accessory interface 412 may include more than one connector to enable connection with more than one accessory.

In some embodiments, keyboard accessory 400 may mediate an accessory connected to keyboard accessory 400. For example, when an accessory is connected to keyboard accessory 400, keyboard accessory 400 may serve as a pass-through (pass-through) entity for the accessory. In this case, although the accessory is actually only directly connected to keyboard accessory 400 and not the PCD, the accessory may communicate directly with the connected PCD without being aware of the presence of keyboard accessory 400. Details of the operation of keyboard attachment 400 as an intermediary are described in co-pending U.S. provisional patent application No.61/292,619, filed on 6/1/2010.

In some embodiments, power for operating the keyboard accessory may be provided by a PCD connected to the keyboard accessory. The keyboard accessory may be designed to be capable of operating at multiple operating voltages. When only a PCD is connected to the keyboard accessory, the keyboard accessory may operate at a first voltage (e.g., 3.3 volts), which may be supplied by the PCD. When the accessory is connected to the PCD via the keyboard accessory, the PCD may also provide power to the accessory via the keyboard accessory. In some embodiments, the accessory may operate at a second voltage (e.g., 4.2 volts) different from the first voltage. In some embodiments, the keyboard accessory may reconfigure itself to operate at the second voltage to operate seamlessly with the PCD and the accessory. Details of this operation are described below in conjunction with fig. 8. It should be noted that the embodiments described above are not limited to accessories including keyboards or input devices. Any functional circuitry within any accessory may be configured to operate at two different voltage levels as described above.

It is to be understood that the system configurations and components described herein are exemplary and that various changes and modifications are possible. The PCD and/or keyboard accessory may have other capabilities not specifically described in this application (e.g., mobile phone, Global Positioning System (GPS), broadband data communication, internet connection capabilities, etc.).

The connectors at each interface may or may not be complementary, as desired. When the two connectors are not complementary, an adapter may be provided to connect the two devices. Furthermore, in some embodiments, some of these connections may be wireless, and the connectors may be omitted where a wireless interface is provided.

Further, although the PCD and keyboard accessories are described herein with reference to specific blocks, it should be understood that these blocks are defined for convenience of description and should not be considered to imply a particular physical configuration of the component parts. Moreover, the blocks do not necessarily correspond to physically separate components. The blocks may or may not be configured to perform various operations (e.g., by programming a processor or providing suitable control circuitry), depending on the manner in which the initial configuration is obtained. Embodiments of the invention may be implemented in various devices including electronic devices implemented in any combination of circuitry or software.

Accessory I/O interface 308 of PCD300 and PCD interface 406 of keyboard accessory 400 enable PCD300 to connect to keyboard accessory 400 and subsequently disconnect from keyboard accessory 400. As used herein, PCD300 and keyboard accessory 400 are "connected" whenever a communication channel is established between accessory I/O interface 308 and PCD interface 406; and whenever such communication channels are terminated, they are "disconnected". The connection may be achieved by physical attachment (e.g., between corresponding mating connectors of PCD300 and keyboard accessory 400), by an indirect connection (e.g., a cable), or by establishing a wireless communication channel. Similarly, disconnection may be accomplished by physically disengaging, disconnecting the cable, shutting down the PCD300, or closing the wireless communication channel. As such, various communication channels may be used, including wired channels (e.g., USB, FireWire, or Universal asynchronous receiver/transmitter ("UART")) or wireless channels (e.g., Bluetooth and WiFi). In some embodiments, multiple communication channels between the PCD and the keyboard accessory may be open at the same time, or the PCD may connect to multiple accessories through the keyboard accessory, each accessory using a different communication channel.

Regardless of the particular communication channel, so long as PCD300 and keyboard accessory 400 are connected to each other, these devices may communicate by exchanging commands and data according to the PCD accessory protocol, which is customized to support communication between the PCD and any of a range of possible accessories. The PCD accessory protocol may define a format for sending messages between PCD300 and keyboard accessory 400. For example, the PCD accessory protocol may specify that each message is sent in a packet (packet) having a header (header) and an optional payload (payload). The header provides basic information (e.g., a start indicator, the length of the packet, and the command to be processed by the recipient), while the payload provides any data associated with the command; the amount of associated data may vary from command to command, and some commands may have variable length payloads. In various embodiments, the PCD accessory protocol may define specific commands to indicate actions to be taken by the recipient; providing a signal for completion of a task, a change in status, or occurrence of an error; and/or identify the nature of the associated data. In some embodiments, these commands may be defined such that a particular command is valid in only one direction. The packet may also include an error detection or error correction code, as is known in the art.

The PCD accessory protocol may define a plurality of "lingos" (lingos), where a "lingo" is a set of related commands that may be supported (or not supported) by various categories of accessories. In some embodiments, a command may be uniquely identified by a first byte that identifies a lingo to which the command belongs and a second byte that identifies a particular command within the lingo. Other command structures may also be used. It is not required that all accessories or all PCDs to which an accessory can connect support each lingo defined in the PCD accessory protocol.

In some embodiments, the keyboard accessory 400 and each PCD300, which are designed to be interoperable with each other, support at least a "universal" lingo that includes commands that are common to all of these devices. The generic lingo may include the following commands: these commands enable the PCD and accessory (e.g., a keyboard accessory) to identify themselves to each other and provide general information about their respective capabilities, including which other lingoes, if any, are each supported. The generic lingo can also include authentication commands that the PCD can use to verify the claimed identity and capabilities of the keyboard accessory and any accessory (or vice versa), and if authentication is unsuccessful, the keyboard accessory and the accessory (or PCD) can be prevented from invoking certain commands or lingoes.

In some embodiments, the keyboard accessory may communicate with the PCD by sending and receiving packets of information using the PCD accessory protocol. In some embodiments, the keyboard accessory may represent keystrokes as USB Human Interface Device (HID) events. In this way, the keyboard accessory can include the USB HID event report into a packet that conforms to the PCD accessory protocol and send the packet to the PCD. The PCD may parse (parse) and interpret the received packet to determine which key was depressed. The USB HID protocol specifies certain reports that may be used by the HID (e.g., keyboard) to communicate with other devices. The USB Device Class Definition for Human Interface Devices (HID), firmware specification, Version 1.11 specification provides a detailed description of various HID reports.

FIG. 5 shows a table 500 listing some of the commands of the PCD accessory protocol that may be used to transfer data between the PCD and a keyboard accessory in accordance with an embodiment of the present invention.

After the PCD connects to the keyboard accessory, the keyboard accessory may send a register descriptor command to the PCD. The register descriptor command may include the following as its payload: HID descriptor for the keyboard, country code, USB vendor ID, USB product ID. Upon receiving the RegisterDescriptor command, the PCD may determine that the keyboard accessory is an HID device. In addition, the RegisterDescriptor command may also inform the PCD that the connected accessory is a keyboard and that the PCD should expect to receive keyboard-related HID events from the connected accessory. In some embodiments, a PCD may register multiple descriptors, which may be associated with an accessory or accessories. In this case, each descriptor may be given some unique identification (e.g., a numeric or alphanumeric code) to track and manage the descriptor.

The keyboard accessory may send an UnregisterDescriptor command to the PCD. The UnregiosterDescriptor command notifies the PCD that the keyboard accessory will no longer send any keyboard-related HID events to the PCD. The UnregisterDescriptor command may include a unique identification of a descriptor associated with an accessory to be unregistered as its payload. For example, the keyboard accessory may send an UnregisterDescriptor command before the PCD is disconnected from the keyboard accessory, or as part of such disconnection process.

The keyboard accessory can send an AccReport command to the PCD. The AccReport command may include a report type and one or more HID events related to one or more key press actions performed on the keyboard attachment. In one example, the AccReport command may be sent to the PCD at regular intervals (e.g., every 8 milliseconds). In some embodiments, if multiple HID events occur between the last transmission and the next transmission (e.g., within 8 milliseconds after the last transmission), the multiple HID events may be aggregated (aggregated) and sent to the PCD as a packet every 8 milliseconds.

The PCD may send a PCDReport (PCD report) command to the keyboard accessory. The PCDReport command may include the type of report and report data, which may include instructions for the keyboard attachment to perform the action. In some embodiments, the PCDReport command may include HID report information to set the keyboard accessory status according to the current PCD status, such as update indicator 408 (e.g., caps lock, digital lock, PCD power/charge, keyboard backlight, etc.). For example, in response to receiving a caps lock key press event from the keyboard by the PCD, the PCDReport command may include an instruction to cause a caps lock indicator on the keyboard accessory to illuminate. In some embodiments, the PCDReport command may also be used to transmit an error message to the keyboard attachment.

In some embodiments, the keyboard accessory may send a key press event command to the PCD when connected with the PCD. When the keyboard accessory is connected to the PCD, the keyboard accessory can send a register descriptor command to the PCD. As described above, the RegisterDescriptor command notifies a PCD that the connected accessory is a keyboard and that the PCD should receive keyboard-related HID events from the accessory. For example, when a user depresses a key on the keypad (e.g., the "A" key), the keyboard generates an HID event related to the key depression and sends the HID event to the PCD using the PCD accessory protocol. Once the PCD receives the PCD accessory protocol command, the command may be parsed to determine that the "A" key on the keypad is depressed, and the PCD may then display the character "A" on the display of the PCD. In some embodiments, the PCD may control various indicator lights on the keyboard accessory based on input received from the keyboard accessory to indicate whether a correct key press event was received. For example, the user may not know whether the PCD received a HID event associated with the caps lock key because the caps lock key would not cause characters to be displayed on the screen. In such a case, after receiving the caps lock event, the PCD may send a command to the keyboard to illuminate an indicator associated with the caps lock key, thereby providing a visual indication that the PCD correctly received the event. In some embodiments, the PCD may control the brightness of the pointer device on the keyboard accessory based on ambient light in the environment surrounding the keyboard accessory, e.g., the brighter the room, the higher the brightness of the pointer device.

While commands related to the PCD and keyboard accessory are described above, it should be noted that any device capable of implementing the PCD accessory protocol may use the commands to send and receive data.

As described above, the PCD and the keyboard accessory may communicate with each other using the PCD accessory protocol. In one embodiment, the PCD may receive a command sent via the PCD accessory protocol and may be able to interpret the command to determine a key press event from information contained in the command. FIG. 6 illustrates a software stack 600 contained in a portable computing device that can be used to interpret commands received from an accessory by packets conforming to the PCD accessory protocol, which may include USB HID reports, in accordance with an embodiment of the present invention. The software stack 600 may be implemented, for example, in the processor 302 of the PCD300 of fig. 3.

A protocol daemon (daemon)602 within the PCD may control PCD accessory protocol communications. In one embodiment, the protocol daemon 602 may receive PCD accessory protocol packets sent by an external device (e.g., a keyboard accessory), extract the commands and any related data, and deliver the message to the protocol manager 606. In another embodiment, the protocol daemon 602 may receive an outbound message from the protocol manager 606 that contains commands and data for the PCD accessory protocol, and may generate a packet containing the message and transmit the packet to an accessory (e.g., a keyboard accessory) connected to the PCD.

Protocol manager 606 can receive PCD attachment protocol messages from protocol daemon 602 and begin the process of interpreting the messages. The protocol manager 606 may read the command code from the message provided by the protocol daemon 602 and determine the nature of the command and any associated payload. Once the protocol manager 606 determines the type of payload, it may deliver the payload to the application support layer 608, the application support layer 608 acting as an intermediary between the protocol manager 606 (and optionally other low-level device functions) and the application 610. The application support layer 608 may provide various summaries that hide implementation details from the application 610. In this way, for example, application 610 can invoke communication with the accessory without knowing the details of the accessory protocol commands or packet structure. In one embodiment, the support layer 608 may include a conventional USB stack for processing USB reports (e.g., HID reports). An example of a Support Layer 608 is described in U.S. patent application No.12/201,874 entitled "Support Layer for organizing Same Access Support Multiple Platforms" filed on 29.8.2008 and commonly owned.

The support layer 608 may interpret commands and data and indicate to the corresponding application the action to be performed in accordance with the command.

The applications 610 may include an Operating System (OS) and/or one or more application programs that implement various functions of the PCD. Various examples include interfaces for navigating a database of media assets, and playing back assets of various types (e.g., audio, video, still images (e.g., photos), etc.). Other examples include web browsers, email programs, word processing programs, spreadsheet programs, presentation programs, personal information management applications (e.g., for managing calendars, tasks, contacts, etc.), geo-navigation programs (e.g., using GPS-enabled capabilities), and so forth.

In some embodiments, the protocol daemon 602 may receive packets containing the AccReport command, extract the command and data (i.e., the HID report) and forward them to the protocol manager 606. The protocol manager 606 may recognize AccReport as indicating that the associated data corresponds to a USB HID report and direct the HID report to the USB stack 612 within the application support layer 608. USB stack 612 may determine that the USB HID report includes a key press event (e.g., related to key "a"). The support layer 608 may then notify the appropriate application that the "A" key was pressed, and the application may perform an action based on this information, such as displaying the character "A" on the display of the PCD.

Similarly, if the application 610 determines that an action of interest should be taken with respect to the keyboard attachment (e.g., capitalization locking should be enabled), the application may instruct the support layer 608 to enable capitalization locking indicators on the keyboard attachment. The support layer 608 may instruct the USB stack 612 to generate an outbound USB HID report indicating that the caps lock indicator should be illuminated and may instruct the protocol manager 606 to propagate the outbound HID report to the PCD. In light of the fact that the accessory communicates via the PCD accessory protocol rather than via USB, the protocol manager 606 can generate a PCDReport command and send a message to the protocol daemon 602 that contains the command and HID report. The protocol daemon 602 can build a PCD accessory protocol packet containing the PCDReport command and the external HID report and can send the command to the accessory according to the PCD accessory protocol.

In one embodiment, the keyboard accessory may generate events related to key presses and other operations performed using the keyboard. In some embodiments, these events may be generated in the form of HID reports that comply with the USB standard. FIG. 7 is a flow diagram of a process 700 for communicating messages between a keyboard accessory (e.g., keyboard accessory 100 of FIG. 1) and a PCD (e.g., PCD 200 of FIG. 2), according to an embodiment of the present invention.

At block 702, a packet compliant with the PCD accessory protocol is received from an external device (e.g., a keyboard accessory). For example, the packet may include an AccReport command and a key press event report generated by the keyboard attachment. The packet may be received, for example, by the protocol daemon 602 of fig. 6. The contents of the packet are determined at block 704.

At block 706, the packet is processed, for example, by the support layer 608, to determine a key press event. For example, a USB HID report may be processed by the USB stack 612, and the USB stack 612 may determine a particular key press event contained in the HID report. Once a key press event is determined, the information may be sent to an appropriate application program, Operating System (OS) program, or other program at block 708. Upon receiving the key press event information, the program may perform an action based on the key press information, such as displaying a character corresponding to the key press event on the display.

It will be appreciated that the process 700 described in the present application is exemplary and that various modifications and variations are possible. Acts described as occurring in sequence may be performed in parallel, the order of the acts may be varied, the acts may be modified and combined. For example, some key press events may cause the PCD to control an indicator on the keyboard accessory in accordance with commands received from the PCD, e.g., pressing a caps lock may cause a caps lock indicator on the keyboard to be illuminated. In other examples, the PCD accessory protocol packet may not include a key press event, but only configuration information for the keyboard accessory.

As described above, one or more HID key press events generated by the keyboard accessory may be sent to the PCD in the form of a USB HID report. In some embodiments, each key press event may be sent in the form of an 8 byte bit mask that is part of the USB HID protocol command. In some embodiments, the USB HID report may be sent as the payload of a PCD accessory protocol command as described above. A controller within the keyboard accessory may receive these key press events and include one or more of these events in a USB HID report to be included as a payload of commands for the PCD accessory protocol. The command may then be communicated to the PCD via the PCD interface connector. The PCD may receive the command through its accessory interface and parse the command to identify the contents of the command, such as described above in connection with fig. 5.

It is to be understood that the processes described herein are exemplary and that various changes and modifications are possible. PCDs may support any type of application that may be launched or exited under control of a user or other process. It is contemplated that the various low-level processes (support layer 608, protocol manager 606, and protocol daemon 602) may be implemented in software and/or firmware and may be configured to automatically start when a device is powered on and terminate only when the device is powered off or various abnormal conditions are detected. These processes may enter an inactive (inactive) state when not in use, so that resource consumption is as low as possible. Moreover, not all of the layers and processes shown in this application are required; for example, in some embodiments, an application may communicate directly with a protocol manager or protocol daemon.

As described above, the keyboard accessory may be designed to work with additional accessories that are connected to the PCD through the accessory port 140 of the keyboard accessory. In many cases, the accessories connected through accessory port 140 may have different operating voltages. In some cases, the operating voltage of the accessory may be different from the operating voltage of the keyboard accessory. In this case, it may be advantageous to operate the keyboard and the accessory at the same voltage, since the operating voltage is provided by the PCD. By having a single operating voltage requirement under these circumstances, the PCD can easily and seamlessly work with multiple accessories without disconnecting the accessories.

FIG. 8 is a flow diagram of a process 800 for operating a keyboard accessory according to an embodiment of the invention. At block 801, the keyboard accessory may determine whether a PCD is connected thereto via a PCD interface. If it is determined that the PCD is not connected, the keyboard accessory may wait for the PCD to connect. If it is determined at block 801 that a PCD is connected to a keyboard accessory, then at block 802 the keyboard accessory may check if there are other accessories connected to the keyboard accessory. If no other accessory is connected to the keyboard accessory, the keyboard may operate at its normal voltage (e.g., 3.3 volts) using power provided by the PCD at block 803. In addition, the keyboard accessory may continuously check whether an accessory is connected to the keyboard accessory. If it is determined at block 802 that an additional accessory is connected to the keyboard accessory, the keyboard accessory may determine the power requirements of the accessory at block 804. In some embodiments, the accessory may automatically send its power requirements to the keyboard accessory when connected. In other embodiments, the keyboard accessory may determine a resistance value between two designated pins (e.g., an accessory detect pin and an accessory ID pin) of the accessory port 140 when the accessory is connected. The resistance value may be indicative of an operating voltage of the accessory. The keyboard accessory may then communicate the power requirements of the accessory to the PCD at block 805. The PCD determines an operating voltage requirement for the accessory upon receiving the power requirement. For example, the PCD may include a lookup table that lists various resistance values of the accessory and their corresponding operating voltages.

The PCD may supply the required operating voltage to the accessory via the keyboard accessory. At block 806, the keyboard accessory receives a voltage from the PCD to operate the accessory. The keyboard accessory may then be used as a conductor to which the voltage received from the PCD is supplied. Additionally, in response to receiving a voltage from the PCD to operate the accessory, the keyboard accessory may begin operating at the same voltage level as the accessory at block 807. In some embodiments, a keyboard accessory may receive a control signal from a PCD indicating that the PCD will supply a voltage equal to the operating voltage of the accessory. When the keyboard accessory receives the control signal, the keyboard accessory may change its operating voltage from its normal value to match the voltage provided by the PCD (which is the accessory's operating voltage). For example, the normal operating voltage of the keyboard accessory may be 3.3 volts and the normal operating voltage of the accessory may be 4.2 volts. Without the accessory, the keyboard accessory may operate at a voltage of 3.3 volts supplied by the PCD. But after the accessory is connected, the keyboard accessory can reconfigure itself to operate at 4.2 volts, i.e., the operating voltage of the accessory.

Enabling the keyboard accessory to operate at different voltages can allow various accessories to be connected to the keyboard accessory for use with the PCD without disconnecting the keyboard accessory from the PCD. This provides more flexibility in the selection of accessories that may be used with the PCD. In addition, the keyboard accessory may also be used to control the accessory, if desired.

It is to be understood that the process 800 described herein is exemplary and that various changes and modifications are possible. Acts described as occurring in sequence may be performed in parallel, the order of the acts may be varied, the acts may be modified or combined. For example, the keyboard accessory may not request power requirements from the accessory; instead, the keyboard accessory will automatically determine the power requirements of the accessory based on the identification of the accessory and access information stored in the memory of the keyboard accessory that lists the power requirements of the various accessories.

Embodiments of the invention may be implemented with any combination of specific components and/or programmable processors and/or other programmable devices. The various processes described herein may be implemented on the same processor or on different processors in any combination. Thus, where various components are described as being configured to perform certain operations, such configuration may be accomplished, for example, by: electronic circuits are designed to perform operations, programmable electronic circuits (e.g., microprocessors) are programmed to perform operations, or any combination thereof. The processes may communicate using a variety of techniques including, but not limited to, conventional techniques for inter-process communication, different pairs of processes may use different techniques, or the same pair of processes may use different techniques at different times. Furthermore, although the above embodiments may refer to specific hardware and software components, those skilled in the art will appreciate that other combinations of hardware and/or software components may be used and that certain operations described as being implemented in hardware may also be implemented in software, and vice versa.

Computer programs incorporating various features of the present invention may be encoded on various non-transitory computer readable media for storage and/or transmission; suitable media include magnetic disks or tapes, optical storage media such as Compact Disks (CDs) or DVDs (digital versatile disks), flash memory, etc. The computer readable medium encoded with the program code may be packaged together with a compatible device or may be provided separately from other devices (e.g., via internet download).

Therefore, while the invention has been described with reference to specific embodiments, it will be understood that the invention is intended to cover all modifications and equivalents within the scope of the appended claims.

Claims (24)

1. An accessory for a portable computing device, the accessory comprising:

an accessory interface configured to connect to and provide power to an additional accessory;

a portable computing device interface configured to connect to and receive power from the portable computing device; and

circuitry configured to operate at a first operating voltage or a second operating voltage, the first operating voltage corresponding to the accessory, the second operating voltage corresponding to the accessory;

wherein the circuitry is further configured to: operating at the second operating voltage when the additional accessory is connected to the accessory interface, and operating at the first operating voltage otherwise.

2. The accessory of claim 1, wherein the second operating voltage is higher than the first operating voltage.

3. The accessory of claim 1, wherein the circuitry is further configured to: a resistance value corresponding to a second power requirement is determined and communicated to the portable computing device.

4. The accessory of claim 1, further comprising a metal body configured to provide stability to the accessory and to provide a ground path to a keypad and the circuit.

5. The accessory of claim 4, wherein the metal body consists essentially of zinc.

6. The accessory of claim 4, wherein the metal body occupies 45% to 55% of the base volume.

7. A method for operating an accessory, the accessory having a first operating power requirement, the method comprising performing by the accessory:

receiving, from an additional accessory connected to the accessory, information associated with a second operating power requirement for operating the additional accessory;

transmitting information associated with a second operating power requirement to a portable computing device connected to the accessory, wherein the second operating power requirement is different from the first operating power requirement;

receiving a voltage corresponding to the second operating power demand from the portable computing device; and

operating using a voltage corresponding to the second operating power requirement.

8. The method of claim 7, wherein the first operating power demand is lower than the second operating power demand.

9. The method of claim 7, wherein receiving information associated with the second operating power demand comprises: determining a resistance value associated with the second operating power demand.

10. An accessory for a portable computing device, the accessory comprising:

a user input device including associated circuitry;

a control section connected to the keypad, the control section comprising:

a first interface configured to accept a portable computing device;

a second interface configured to accept another accessory;

a control circuit coupled to the first interface and the second interface; and

a metal body constituting more than 50% of a total mass of the accessory, the metal body configured to provide a ground connection to the keypad circuitry and the control circuitry.

11. An accessory according to claim 10 wherein the user input device is a keyboard.

12. The accessory of claim 10, wherein the accessory is configured to communicate with the portable computing device using a set of commands comprising:

a first command transmittable by the accessory to the portable computing device, the first command including configuration information related to the accessory; and

a second command transmittable by the accessory to the portable computing device, the second command including a USB HID report associated with one or more key press events on the keypad.

13. The accessory of claim 10, further configured to:

determining a resistance value associated with a power requirement of the other accessory connected to the second interface; and

communicating the resistance value to the portable computing device.

14. An accessory for a portable computing device, the accessory comprising:

a keypad including one or more keys;

a portable computing device interface configured to communicate with the portable computing device using a device-specific protocol customized for the portable computing device, the protocol comprising a defined set of commands; and

a controller coupled to the keypad and the portable computing device interface and configured to generate commands of a device-specific protocol to be transmitted to the portable computing device, wherein the set of commands includes:

a first command transmittable by the accessory to the portable computing device, the first command including configuration information related to the accessory; and

a second command transmittable by the accessory to the portable computing device in response to user operations on the keys of the keypad, the second command including information identifying one or more of the keys of the keypad that were operated.

15. The accessory of claim 14, wherein the set of commands further comprises:

a third command receivable by the accessory, the third command instructing the accessory to illuminate an indicator associated with the key.

16. The accessory according to claim 14, wherein the configuration information includes an HID descriptor, a country code, a USB vendor ID, a USB product ID for the accessory.

17. The accessory of claim 14, wherein the information identifying one or more keys in the keypad is a USB HID report.

18. An accessory for a portable computing device, the accessory comprising:

a base member having a front surface, a rear surface, a top surface, a substantially flat bottom surface, and at least one narrow support portion projecting below the bottom surface, the support portion extending substantially the entire width of the base member and being disposed at a first end of the bottom surface further from the front surface;

a docking connector extending upwardly from a top surface of the base member, the docking connector adapted to connect to a portable computing device; and

a keypad section having a keypad joined to the base section near a top edge of the front surface and extending diagonally forward and downward from the front surface, the keypad section having a first support at a first lower corner and a second support at a second lower corner,

wherein the support portion of the base section and the first and second supports of the keypad section are arranged such that: when the keyboard accessory is placed on a substantially flat placement surface, the support portion of the base section and the first and second supports of the keypad section are in contact with the placement surface, and the substantially flat bottom surface of the base section is held apart from the placement surface.

19. The attachment of claim 18, wherein the base member comprises a zinc body.

20. An accessory according to claim 19 wherein said base member includes a control panel for controlling operation of said keyboard accessory, said control panel being grounded through said zinc body.

21. The accessory of claim 18, further comprising an accessory connector disposed on the rear surface, the accessory connector configured to accept and couple an additional accessory to the portable computing device.

22. A method for communicating between an accessory and a portable computing device, the method comprising performing, by the portable computing device:

receiving a command from the accessory, the command complying with a PCD accessory protocol and including information relating to a key press event, the PCD accessory protocol being customized to facilitate communication between the portable computing device and the accessory;

analyzing the command to determine a key press event included in the command; and

and executing an action according to the key pressing event.

23. The method of claim 22, wherein analyzing the command comprises:

transmitting information related to the key press event to a software stack within the portable computing device; and

determining a key press event based at least in part on information related to the key press event.

24. The method of claim 22, wherein the information related to the key press event is an accessory HID report.