JP2005130316A - Image input device and method for switching communication protocols - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To deal with a plurality of communication protocols without user's specification. <P>SOLUTION: Connection is established in the state of communication by a first communication protocol (s401 and s402). When a predetermined request is received (s405); connection release is notified to a host device (s407), the communication protocol is switched to a second communication protocol (s408), and a reconnection is notified to the host device (s409). After the predetermined request is received (s410), use of the second communication protocol is started (s411). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image input device such as a digital camera and a communication protocol switching method in this type of image input device.

  One of network interfaces for connecting a digital camera to a personal computer or a printer is a USB (Universal Serial Bus) (see, for example, Non-Patent Document 1).

When connecting a digital camera to a personal computer or printer using USB, it is necessary to implement the following two communication protocols. That is,
(1) A communication protocol (hereinafter referred to as a standard protocol) defined by a mass storage class, an imaging class, or the like.
(2) A communication protocol uniquely defined by the vendor (hereinafter referred to as a vendor-specific protocol).
Universal Serial Bus Specification Revision 2.0, April 27, 2000

  When both the standard protocol and the vendor specific protocol are implemented, a function for efficiently switching between these communication protocols is required.

  An object of the present invention is to provide an image input apparatus capable of efficiently switching between a standard protocol and a vendor-specific protocol, and a communication protocol switching method thereof.

  An image input device according to the present invention includes a communication module capable of executing at least two communication protocols, and a plurality of communication protocols according to a type of the communication start request in response to a predetermined communication start request from an external communication device. A protocol selection means capable of selecting one from the above and executing it exclusively, and immediately after receiving the communication start request, issues a disconnection request from the bus to the external communication device, A disconnection request issuing means for releasing the request, and a bus configuration request issuing means for outputting a connection request to the external communication device again when the protocol selected by the protocol selection means can be executed. It is reconfigured with the protocol selected for.

  A communication protocol switching method according to the present invention is a method for switching a communication protocol in an image input apparatus having a communication module capable of executing the first and second communication protocols, wherein the external communication apparatus uses the first communication protocol. In the state of communicating with the external object communication device, in response to a predetermined communication start request from the external object communication device, by issuing a disconnection request from the bus to the external communication device, the connection state is once released, and the communication The communication protocol used in the module is switched to the second communication protocol, and when the second communication protocol can be executed, a connection request is output again to the external communication device. To do.

According to the present invention, the standard protocol and the vendor specific protocol can be switched efficiently.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic block diagram of a digital camera system according to an embodiment of the present invention. The present embodiment is roughly divided into a digital camera 100 and an information processing apparatus 101. The information processing apparatus 101 includes, for example, a computer (PC), an arithmetic processing unit (CPU), a primary storage unit (RAM), a secondary storage unit (hard disk), an operation device (keyboard, mouse), and a display device (not shown). Display) and the like. The present embodiment is not limited to a digital camera, and can also be implemented in an image input device (digital video camera, mobile phone with camera, mobile terminal with camera, etc.) other than a digital camera.

  The digital camera 100 includes an optical unit 105 including a lens, an image sensor, a drive circuit, and the like, an image processing unit 104 that processes image data captured by the optical unit 105, a calculation unit 103 such as a CPU, and a primary storage such as a DRAM. Device 106, secondary storage device 107 such as built-in flash ROM, operation unit 108, display unit 109 such as LCD liquid crystal, read-only memory 110 such as ROM used for storing programs, removable recording such as flash memory card The communication control unit 102 manages the connection with the medium 111 and the information processing apparatus 101. Only one of the secondary storage device 107 and the removable storage medium 111 may be provided.

  FIG. 2 shows how the digital camera 100 shown in FIG. 1 is connected to a computer and a printer. 201 is a PC and 202 is a printer.

  It is common to connect the digital camera 100 to the PC 201. In this embodiment, the digital camera 100 and the PC 201 are connected using a USB. In this case, the PC 201 provides a USB host function, and the digital camera 100 becomes a slave device.

  The printer 202 is also connected to the digital camera 100 via USB. In this case, the printer 202 provides a USB host function, and the digital camera 100 becomes a slave device.

  When the digital camera 100 is connected to the PC 201, the PTP defined by the imaging class (reference: PIMA 15740: 2000, Photography-Electronic still picture imaging-Picture Transfer Protocol (PTP) for Digital Still When communicating with the PC 201 and connecting to the printer 202 using the Photography Devices, PHOTOGRAPHIC AND IMAGING MANUFACTURERS ASSOCIATION, INC., Approved 2000-07-05, First EDITION) Communicate with 202. The communication protocol to be used is automatically selected according to the model or type of the connection partner.

  FIG. 3 shows an example of state transition inside the digital camera 100.

  The digital camera is connected to the host device via the USB cable. When the host device is activated and in a communicable state, the host device supplies a voltage of 5 V to the USB VBUS signal. When the digital camera detects the 5V voltage, it starts up as Not Configured Status, initializes itself, pulls up the USB D + signal, notifies the host device of the connection, and notifies the Bus Configured Status of its own status. Transition. In this state, the digital camera receives some standard requests from the host device and returns necessary information to the host device.

  When the digital camera is assigned a USB address from the host device and completes transmitting various information, the digital camera shifts to the Idle Waiting for command status. Here, it waits for reception of a PTP command. When receiving the PTP command, the digital camera shifts to Command Phase and executes the received command. Some commands involve data transfer. In that case, the digital camera shifts to Data Phase, transfers data, and transmits response data to the host device. When data transfer is not involved, the digital camera immediately shifts to Response Phase and transmits response data to the host device.

  Thereafter, the digital camera returns to the idle waiting for command phase and waits for the next command.

  When the digital camera receives a request other than the PTP command from the host device in the idle waiting for command phase, it basically stalls. However, if the request is a vendor-specific request that is a WakeUp request that indicates the start of a unique command, the digital camera shifts to a Logical Connecting status and enters a connection processing state for the unique command. In this state, when a command according to a predetermined connection sequence unique to the vendor is received from the host device, the digital camera shifts to Logical Connected status, enabling execution of commands and data transfer according to the vendor's unique command system. Become. In the Logical Connected status, the digital camera does not accept a normal PTP operation (command) or the like.

  When receiving a Shutdown request for ending the unique command system from the host device in the Logical Connected status, the digital camera returns to the Idle waiting for Command Phase again. With this idle waiting for command phase, the digital camera can no longer accept vendor-specific commands and can receive PTP commands.

  With reference to the flowchart shown in FIG. 5, the details of the connection process when a printer or PC is connected to the digital camera of this embodiment will be described.

  When the digital camera is connected to the host device, 5V is supplied to the USB VBUS signal line. When the digital camera detects 5V, the digital camera initializes its own various registers so that USB communication is possible (s401).

  The digital camera then responds to the USB standard request from the host device and returns a device descriptor, a configuration descriptor, etc. to the host device (s402). When recognized as a device by the host device and configured on the USB bus, the digital camera waits for a request from the host device (s403). In this state, when the connection partner is a normal PC, a PTP command such as GetDeviceInfo operation is transmitted to the digital camera. If it is determined that the received command is a PTP request (s404), the digital camera ends the connection process and proceeds to a PTP command execution process.

  If it is determined that the request is not a PTP request, it is determined whether this request is a vendor-specific Wakeup request (s405). If it is determined that the request is not a vendor-specific Wakeup request, the request is stalled (s406), and the process returns to the next request wait state.

  If it is determined that the request is a vendor-specific Wakeup request, the digital camera releases the pull-up state of the USB D + signal line to notify the host device that it is disabled (s407). Thereafter, the digital camera switches its setting to a vendor-specific command (s408), pulls up the USB D + signal line again, and announces reconnection to the host device (s409).

  The digital camera determines that the connection partner is a printer that operates using a vendor-specific command, and waits for a vendor-specific Wakeup request to be issued from the connection partner (s410). Upon receiving the Wakeup request, the digital camera enters a vendor-specific command reception state, and thereafter ends the connection process to shift to actual command processing.

  The operation of receiving a vendor-specific Wakeup request when the digital camera is in the idle waiting for command phase and switching the internal setting to the vendor-specific protocol will be described with reference to FIG.

  The present embodiment uses four Endpoints of USB Control, BulkIn, BulkOut, and Interrupt. Among them, the usage of three of Control, BulkIn, and BulkOut differs between PTP and the vendor-specific protocol. Each Endpoint process is handled by an interrupt. Therefore, as shown in FIG. 5, when the camera is activated, an interrupt processing routine for each endpoint is set as for PTP, a vendor-specific wakeup request is received, and the internal state shifts to a logical connecting status. , Control, BulkIn, and BulkOut interrupt processing routines are reset for vendor-specific protocols to switch processing.

  When the vendor-specific protocol is finished and a ShutDown request is received, the control processing routines of Control, BulkIn, and BulkOut are returned to those for PTP, and the internal state is returned to Idle waiting for Command Phase. Thereby, a PTP command can be accepted.

  Thus, according to the digital camera 100 according to the present embodiment, the standard protocol and the vendor specific protocol can be switched efficiently.

  In addition, according to the digital camera 100 according to the present embodiment, it is necessary to implement both the conventional unique command and the standard command, but it is assumed that either one operates exclusively with respect to each other. Compared with the case where two communication protocols are operated simultaneously, the required hardware scale can be reduced and the cost can be reduced.

  Further, according to the digital camera 100 according to the present embodiment, since the camera automatically operates by switching the communication protocol by using on / off of the bus, it is unnecessary to explicitly switch the communication protocol to the user. become. In other words, it is not necessary for the user to switch communication protocols consciously, and an easily understandable and highly compatible system can be constructed.

It is a schematic block diagram of one Example of this invention. It is a schematic diagram of the example of a connection aspect of a present Example. It is a state transition diagram inside the digital camera of the present embodiment. It is an operation | movement flowchart of a present Example. It is a schematic diagram which shows the state transition according to a connection other party.

Explanation of symbols

100: Digital camera 101: Information processing device 102: Communication control unit 103: Calculation unit 104: Image processing unit 105: Optical unit 106: Primary storage unit 107: Secondary storage unit 108: Operation unit 109: Display unit 110: Read-only Memory 111: Removable recording medium

Claims (4)

A communication module capable of executing at least two communication protocols;
Protocol selection means capable of selecting and exclusively executing one of the plurality of communication protocols according to a type of the communication start request in response to a predetermined communication start request from an external communication device;
Immediately after receiving the communication start request, issue a disconnection request from the bus to the external communication device, and a disconnection request issuing means for releasing its own connection state;
Bus configuration request issuing means for outputting a connection request to the external communication device again when execution of the protocol selected by the protocol selection means becomes possible. An image input device configured to be configured.   When an end request indicating the end of the communication protocol currently in use is received from the external communication device, the communication protocol applied by the communication module is the communication protocol used immediately before the communication protocol currently in use. The image input device according to claim 1, wherein the image input device is switched to the image input device. A method for switching communication protocols in an image input apparatus having a communication module capable of executing first and second communication protocols,
By issuing a disconnection request from the bus to the external communication device in response to a predetermined communication start request from the external communication device in a state of communicating with the external communication device using the first communication protocol, Release the connection once,
Switching the communication protocol used in the communication module to the second communication protocol;
A communication protocol switching method, wherein a connection request is output again to the external communication device when execution of the second communication protocol becomes possible.   4. The communication according to claim 3, wherein when a termination request indicating termination of the second communication protocol is received from the external communication device, the communication protocol applied by the communication module is switched to the first communication protocol. 5. Protocol switching method.

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