JP2006318359A - Usb system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a USB system without requiring a file system to be held in a printer which serves as a USB host, in a camera direct print system using a USB MassStorage class. <P>SOLUTION: In a system transferring data by means of a USB (Universal Serial Bus) interface, expansion to the MassStorage class is carried out in both of the USB host and a USB device and a command for transferring print data is added since a file system is not required on the USB host side when the MassStorage class is provided as a communication protocol between the USB host 101 and the USB device 102. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a USB system that performs printing using a USB interface, and relates to a USB system that does not require a file system on the printer side when both the USB host and the USB device have a MassStorage class as a communication protocol.

  Traditionally, devices such as printers and digital cameras were equipped with a USB interface for the purpose of connecting to a PC. That is, for example, to print an image shot with a digital camera, first connect the digital camera to the PC, transfer the image to the PC, then connect the printer to the PC and print the previous image. There was a need.

  In recent years, in order to eliminate the inconvenience that cannot be printed unless this procedure is followed, several USB systems have been disclosed in which an image capturing device and a printing device, for example, a digital camera and a printer are directly connected via USB.

  At this time, the USB host must supply power to the USB device, so the printing device that can supply power relatively stably plays its role, and the image capturing device operates as a USB device. I often design systems.

  In addition, as a communication protocol for the printing apparatus and the image capturing apparatus, a vendor-specific USB class is defined, or a standard class such as MassStorage class or Still Image Capture Device class is adopted.

  In particular, the USB class installed in the image capture device does not increase the cost of installing multiple classes in the image capture device because the function to transfer images held by the image capture device to the PC is still required. Therefore, the system is often designed to operate with the same communication protocol.

  Among them, the MassStorage class is often adopted as a communication protocol because a driver has been installed on the PC side from the early days of the introduction of the USB interface and many operating systems supported it.

  In addition, the user interface at the time of USB connection such as print start designation is often provided in the image capturing apparatus because the image capturing apparatus includes a display device and an input device for its function.

In Japanese Patent Laid-Open No. 2001-290612, in the USB connection described above, when a printer serves as a USB host, a digital camera serves as a USB device, and a MassStorage class is adopted as a communication protocol, a USB having a user interface on the printer side A system has been proposed.
Japanese Patent Laid-Open No. 2001-290612

  However, in the above USB connection, when building a USB system in which a printer serves as a USB host, a digital camera plays a role as a USB device, and a MassStorage class is adopted as a communication protocol, the connection with the PC is considered. Although the printer of the printing device does not need to have a file system, the mass storage class of the communication protocol has a communication system as a block device, so the file system must be installed on the printer side. There is a problem.

  This further includes a problem that a desired USB system cannot be constructed unless the image capturing apparatus is stored in the file system format desired by the printing apparatus.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is communication between a USB host and a USB device in a system for transferring data using a USB interface. When the MassStorage class is used as the protocol, the USB device is guaranteed to be connected to the PC, and the USB host side does not need a file system without increasing the installed class. Even so, it is to provide a USB system that can build a USB system.

  In order to achieve the above object, the USB system according to claim 1 is a system that transfers data using a USB interface, and has a MassStorage class as a communication protocol between a USB host and a USB device. It is characterized by extending MassStorage class in both USB host and USB device so that the system is not required.

  In order to achieve the above object, the USB system according to claim 2 is characterized in that the USB host is a printing device.

  In order to achieve the above object, the USB system according to claim 3 is characterized in that the USB device is an image photographing device.

  In order to achieve the above object, the USB system according to claim 4 is characterized in that the data transferred using the USB is print data.

  In order to achieve the above object, the USB system according to claim 5 is characterized in that the extension of the MassStorage class is a command for a USB host to request print data from a USB device.

  In order to achieve the above object, the USB system according to claim 6 is characterized in that the USB device has a file system.

  In order to achieve the above object, the USB system according to claim 7 is characterized in that the USB device holds a user interface when a user designates printing.

  In order to achieve the above object, the USB system according to claim 8 is characterized in that the USB device has a file system.

  In order to achieve the above object, the USB system according to claim 9 is characterized in that the USB device can be connected to a plurality of types of USB hosts without mounting a plurality of classes.

  In order to achieve the above object, the USB system according to claim 10 is characterized in that data transfer is possible regardless of what file system the USB device employs.

  As described above in detail, according to the USB system of the present invention, in the system for transferring data using the USB interface, when the Mass Storage class is provided as a communication protocol between the USB host and the USB device, the file system is provided on the USB host side. There is an effect that it is not necessary.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. For convenience of explanation, in this embodiment, a printing device as a USB host is represented as a printer, and an image photographing device as a USB device is represented as a digital camera.

(First embodiment)
First, a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 3 is a conceptual diagram showing a conventional example of a USB host and a USB device in the USB system according to the present embodiment. In this figure, 301 is a printer, 302 is a digital camera, 303 is a USB cable, 304 is a mechanism for operating the printer as a USB host for MassStorage, 305 is a file system, 306 is a mechanism for operating the digital camera as a USB device for MassStorage, Reference numeral 307 denotes a file system, and 308 denotes a user interface mechanism for performing print designation and the like.

  Data captured by the 302 digital camera is stored in the 302 camera using a 307 file system.

  When a 302 digital camera is connected to a PC via USB, it communicates with the PC using a mechanism that operates as a USB device of 306 MassStorage.

  When a 301 printer and a 302 digital camera are connected by a 303 USB cable, if the 301 printer detects that the user has designated printing by a user interface mechanism that performs 308 printing or the like, the 301 printer Using a mechanism that operates as a USB host of the 304 MassStorage, an instruction is given to acquire desired block device data from the 302 digital camera. Upon receiving this command, the 302 digital camera transmits the requested block device data using a mechanism that operates as a USB device of 306 MassSotrage. The 301 host receiving this data extracts the corresponding file data using the 305 file system and prints it.

  FIG. 1 is a conceptual diagram showing a USB host and a USB device in the USB system according to the present embodiment. In the figure, 101 is a printer, 102 is a digital camera, 103 is a USB cable, 104 is a mechanism that operates as a USB host of MassStorage, 105 is an expansion mechanism of the MassStorage class in the USB host, and 106 is a mechanism that operates as a USB device of MassStorage. 107 denotes an extension mechanism of the MassStorage class in the USB device, 108 denotes a file system, and 109 denotes a user interface mechanism for performing printing or the like.

  Data captured by the 102 digital camera is stored in the 102 digital camera using the 108 file system.

  When the 102 digital camera is connected to the PC via USB, it communicates with the PC using a mechanism that operates as a 106 MassStorage USB device.

  When the 101 printer and the 102 digital camera are connected by a 103 USB cable, USB initial processing is performed by a mechanism that operates as a 104 MassStorage USB host and a mechanism that operates as a 106 MassStorage USB device. Thereafter, a print data request command is transmitted from the 101 printer to the 102 digital camera using the MassStorage class expansion mechanism in the 105 USB host in a form adapted to the data system of the MassStorage class. In the 102 digital camera, the data specified by the user interface mechanism for 109 printing by the user is extracted from the corresponding file data using the 108 file system, and the request of the printer is requested by the mass storage class expansion mechanism in the 107 USB device. Send in response to the command. The 101 printer that has received this data performs print processing based on the data.

  FIG. 2 is a conceptual diagram illustrating an example of connection of a USB host and a USB device using a USB interface in the USB system according to the present embodiment. In the figure, 201 is a PC that plays the role of a USB host, 202 is a printer that plays the role of USB host, 203 is a PC that plays the role of USB host, 204 is a printer that plays the role of USB device, and 205 is the role of USB device Reference numeral 206 denotes a digital camera that plays the role of a USB device.

  A 201 PC and a 204 printer, a 202 printer and a 205 digital camera, and a 203 PC and a 206 digital camera are connected by a USB cable, respectively, to perform communication. At this time, since both the 205 digital camera and the 206 digital camera operate as the MassStorage class, hardware resources and software resources for installing a plurality of classes in the digital camera are not necessary.

  FIG. 4 is a block diagram illustrating a hardware configuration example of an information processing apparatus including a configuration of a USB host and a USB device device in the USB system according to the present embodiment. In this figure, 401 is a CPU (central processing unit), 402 is a RAM (random access memory), 403 is a ROM (read only memory), 404 is an I / O controller, 405 is a USB host / device controller, and 406 is a bus. Is shown.

  The present invention is constituted by hardware constituted by 401 and 402, 403, 404, and 405 in FIG. Necessary modules can be freely combined. For example, they can be added via a mechanism 406 or the like.

  This figure is only an example of a hardware configuration according to the present embodiment, and other configurations such as a configuration in which modules are connected by a plurality of buses, a 405 USB host / device controller connected via a 404 I / O controller, and the like. Various forms are conceivable, such as connecting modules via modules.

  FIG. 5 shows processing including the mass storage class expansion mechanism in the USB host in the USB system according to the present embodiment.

  In step S501, the printer connected to the digital camera via USB assigns an address corresponding to USB initialization processing, and the process proceeds to step S502.

  In step S502, a print data request command that is an extended mechanism of the MassStorage class in the USB host is transmitted to the digital camera, and the process advances to step S503.

  In step S503, it is determined whether print data is received or Nack is received. If print data is received, the process proceeds to step S504. If Nack is received, the process proceeds to step S502.

  In step S504, print processing is performed based on the received print data, and the processing including the MassStorage class extension mechanism in the USB host is completed.

  The firing condition of this process may be the time when the printer detects the connection of the digital camera, but the firing condition is not related to the present invention.

  If the received packet is Stall in the process from Step S503 to Step S502, it can be detected that a USB device that does not have the MassStorage class extension mechanism in the USB device is connected. It is also possible to perform processing so as to cancel.

  FIG. 6 shows processing including the mass storage class expansion mechanism in the USB device in the USB system according to the present embodiment.

  In step S601, in response to the USB initialization process from the USB host, the process proceeds to step S602.

  In step S602, it is determined whether a print data transmission command is received from the printer. If received, the process proceeds to step S603, and if not received, the process proceeds to step S605.

  In step S603, a user specifies a print using a user interface mechanism that performs print specification or the like, and the process advances to step S604.

  In step S604, the file data designated by the user is read and transmitted to the printer, and the process advances to step S607.

  In step S605, it is determined whether a MassStorage command other than the print data transmission command has been received. If received, the process proceeds to step S606. If not received, the process proceeds to step S602.

  In step S606, it operates as a normal MassStorage class and proceeds to step S607.

  In step S607, processing necessary for disconnection is performed in response to disconnection of the USB cable, and processing including the MassStorage class extension mechanism in the USB device is terminated.

  The ignition condition of this process may be USB initial communication from the USB host or USB cable connection, but the ignition condition is not related to the present invention.

  If it is connected to the printer, the process advances to step S603 to perform processing for printing. If it is connected to a USB host other than the printer, a normal MassStorage class operation is performed in step S606.

  In this process, print designation from the user is performed in step S603. In addition to receiving the print data transmission command, the user input may be validated before the USB cable is connected. When the print designation from the user is ignited is not related to the present invention. However, it is necessary to complete or have all necessary data before the print data transmission stage in step S604.

  In this process, it is constructed so that the process proceeds to step S602 when the MassStorage command is not received in step S605. However, it is possible to construct so that the process proceeds to step S607, but the explanation of the operation in this case is the same. Omitted.

  In this process, it is constructed so as to judge step S605 after judging step S602. However, it can be constructed so that step S602 is judged after judging step S605, but the operation explanation in this case is similar. Omitted.

  In this process, the print data is responded and the normal MassStorage is separately constructed, but it is also possible to construct so that it can respond to both.

  FIG. 7 shows a case where communication is performed in the USB system according to the present embodiment using the processing of the MassStorage class expansion mechanism in the USB device shown in FIGS. 5 and 6 and the processing of the MassStorage class expansion mechanism in the USB host. Shows an example of USB communication in chronological order.

  First, the initial USB communication is sent from the printer, and the digital camera responds to it. Next, initial communication of MassStorage class is sent and the digital camera responds. If successful so far, the printer transmits a print data request command for requesting data to be printed. The digital camera makes a Nack response until it is ready. The digital camera transmits print data when the data is ready.

  By implementing as described above, in a system that transfers data using the USB interface, a USB system that does not require a file system on the USB host side when having a MassStorage class as a communication protocol between the USB host and the USB device Can be built.

(Second embodiment)
Further, as a second embodiment of the present invention, in the above-described first embodiment, the printer has shown an implementation that always waits for the response of the digital camera by transmitting a print data request command. The present invention can also be applied to a form for notifying completion of print data preparation.

  Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.

  FIG. 8 shows processing including an extension mechanism of the MassStorage class in the USB host in the USB system according to the present embodiment.

  In step S801, the printer connected to the digital camera via USB performs address assignment or the like, which corresponds to USB initialization processing, and proceeds to step S802.

  In step S802, it is determined whether a print start notification has been received from the digital camera. If received, the process proceeds to step S803. If not received, the process proceeds to step S802.

  In step S803, a print data request command, which is an extension mechanism of the MassStorage class in the USB host, is transmitted to the digital camera, and the process advances to step S804.

  In step S804, print processing is performed based on the received print data, and the processing including the MassStorage class extension mechanism in the USB host ends.

  The firing condition of this process may be the time when the printer detects the connection of the digital camera, but the firing condition is not related to the present invention.

  If the print data request command does not arrive in step S802, the usb state may be changed to the suspend state or the disconnection process may be performed, but this case is not related to the present invention.

  FIG. 9 shows processing including an extension mechanism of the MassStorage class in the USB device in the USB system according to the present embodiment.

  In step S901, in response to the USB initialization process from the USB host, the process proceeds to step S902.

  In step S902, it is determined whether a normal MassStorage block device command is received. If received, the process proceeds to step S905. If not received, the process proceeds to step S903.

  In step S903, print designation from the user is performed using a user interface mechanism for performing print designation or the like, and the process advances to step S904.

  In step S904, a print start notification is transmitted to the USB host, and the process advances to step S905.

  The file data designated in step S905 is read and transmitted to the printer, and the process advances to step S907.

  In step S906, the operation is performed as the MassStorage class, and the process advances to step S907.

  In step S907, the USB cable is cut and processing necessary for cutting is performed, and the processing including the MassStorage class extension mechanism in the USB device is terminated.

  The ignition condition of this process may be USB initial communication from a USB host or USB cable connection, but the ignition condition is not related to the present invention.

  If it is connected to the printer, the process proceeds to step S903 to perform processing for printing. If it is connected to a USB host other than the printer, a normal MassStorage class operation is performed in step S905.

  In this processing, print designation from the user is performed in step S903, but it is also conceivable that the user input is made valid before the USB cable is connected. When the print designation from the user is ignited is not related to the present invention. However, it is necessary to complete or obtain necessary data by the print data transmission stage in step S904.

  In this process, the print data is responded separately and the normal MassStorage is responded separately, but it is also possible to construct it so that it can respond to both.

  In step S904 of this process, a print start notification is transmitted to the USB host, but the method is not related to the present invention.

  FIG. 10 shows a case where communication is performed in the USB system according to the present embodiment using the processing of the MassStorage class expansion mechanism in the USB device shown in FIGS. 8 and 9 and the processing of the MassStorage class expansion mechanism in the USB host. Shows an example of USB communication in chronological order.

  First, the initial USB communication is sent from the printer, and the digital camera responds to it. Next, initial communication of MassStorage class is sent and the digital camera responds. If successful so far, the digital camera prepares the print data, and when ready, sends a print start notification to the printer. In response, the printer transmits a print data request command requesting data to be printed. The digital camera transmits the data prepared earlier.

  Since other implementations are the same as those in the first embodiment, description thereof is omitted.

  By implementing the above, in a system that transfers data using the USB interface, a USB system that does not require a file system on the USB host side when the Mass Storage class is used as a communication protocol between the USB host and the USB device. Can be built. In addition, compared with the first embodiment, this embodiment can reduce the amount of USB transfer.

It is a conceptual diagram which shows a USB host and a USB device in the USB system which concerns on 1st embodiment of this invention, and 2nd embodiment. It is a conceptual diagram which shows the example of the connection by the USB interface of the USB host and USB device in the USB system which concerns on 1st embodiment of this invention, and 2nd embodiment. It is a conceptual diagram which shows the conventional example of the USB host and USB device in the USB system which concerns on 1st embodiment of this invention, and 2nd embodiment. It is a block diagram which shows the hardware structural example of the information processing apparatus which comprised the structure of the USB host and USB device apparatus in the USB system which concerns on 1st embodiment of this invention, and 2nd embodiment. It is a flowchart figure which shows the process including the extension mechanism of the MassStorage class in a USB host in the USB system which concerns on 1st embodiment of this invention. It is a flowchart figure which shows the process including the expansion mechanism of the MassStorage class in a USB device in the USB system which concerns on 1st embodiment of this invention. Example of USB communication when communication is performed using processing of the MassStorage class extension mechanism in the USB device and processing of the MassStorage class extension mechanism in the USB host in the USB system according to the first embodiment of the present invention. It is the figure represented to the time series. It is a flowchart figure which shows the process including the expansion mechanism of the MassStorage class in a USB host in the USB system which concerns on 2nd embodiment of this invention. It is a flowchart figure which shows the process including the expansion mechanism of the MassStorage class in a USB device in the USB system which concerns on 2nd embodiment of this invention. Example of USB communication when communication is performed using processing of the MassStorage class extension mechanism in the USB device and processing of the MassStorage class extension mechanism in the USB host in the USB system according to the second embodiment of the present invention It is the figure represented to the time series.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Printer 102 Digital camera 103 USB cable 104 Mechanism to operate as USB host of MassStorage 105 Extension mechanism of MassStorage class in USB host 106 Mechanism to operate as USB device of MassStrage 107 Extension mechanism of MassStorage class in USB device 108 File system 109 User interface Mechanism 201 USB host PC
202 USB host printer 203 USB host PC
204 USB Device Printer 205 USB Device Digital Camera 206 USB Device Digital Camera 301 Printer 302 Digital Camera 303 USB Cable 304 Mechanism to Operate as MassStorage USB Host 305 File System 306 Mechanism to Operate as MassStorage USB Device 307 File System 308 User interface mechanism 401 CPU (central processing unit)
402 RAM (random access memory)
403 ROM (read only memory)
404 I / O controller 405 USB host / device controller 406 bus

Claims (10)

  In a system that transfers data using the USB (Universal Serial Bus) interface, when the MassStorage class is used as a communication protocol between the USB host and the USB device, a USB host and USB device are not required because no file system is required on the USB host side. USB system characterized by extending the MassStorage class on both.   The USB system according to claim 1, wherein the USB host is a printing device.   The USB system according to claim 1, wherein the USB device is an image photographing device.   The USB system according to claim 1, wherein the data transferred using the USB is print data.   5. The USB system according to claim 1, wherein the extension of the MassStorage class is a command for a USB host to request print data from a USB device. 6. The USB system according to claim 1, 2, 3, 4 or 5, wherein the USB device has a file system.   The USB system according to claim 1, 2, 3, 4, 5, or 6, wherein the USB device holds a user interface when a user designates printing.   The USB system according to claim 1, 2, 3, 4, 5, 6 or 7, wherein the USB device has a file system.   The USB system according to claim 1, 2, 3, 4, 5, 6, 7, or 8, wherein the USB device can be connected to a plurality of types of USB hosts without mounting a plurality of classes.   The USB system according to claim 1, 2, 3, 4, 5, 6, 7, 8, or 9, wherein data transfer is possible regardless of the file system used by the USB device.

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