JP2002140281A - Switching device and its method, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the connection of a retractable interface such as a USB easily switchable. SOLUTION: When printing is carried out in a computer device 4B unselected in a USB switching device 1 and printing data are supplied to a USB function 13B, the printing data supplied to the USB function 13B are not taken in by means of a control part 11, but a BUSY signal showing that the printer is in processing is supplied to a USB host 21B. The computer device 4B is set in a printing data transmission waiting condition while the BUSY signal is supplied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
niversal Serial Bus), the connection can be switched by an interface that can be hot-swappable and that reads and destroys driver software each time it is inserted and removed.
The present invention relates to a switching device and a method that can be performed more easily, and an image display device.

[0002]

2. Description of the Related Art In recent years, there has been a USB (Universal Serial Bus) as an interface for connecting information processing devices, especially computer devices to peripheral devices and the like. USB
Supports a plurality of transfer modes, automatically recognizes connected peripheral devices, and automatically incorporates necessary device drivers. Therefore, the user can connect and use the peripheral device with a computer device or the like without being conscious of the type of the peripheral device to be connected. As typical peripheral devices adopting USB for the interface, for example, there are a keyboard, a mouse, a printer device, a scanner device, and the like, which are used by being connected to a computer device.

[0003] In addition to the ease of connection as described above, USB has a data transfer speed of several megabytes / sec to several tens of bytes.
Mbytes / sec (or several hundred Mbytes / sec
c), which is faster than a conventional serial interface such as RS-232, and is also rapidly becoming popular because it can be connected to a bus.

[0004] By the way, when a plurality of, for example, two computer devices are owned and used simultaneously, it is conceivable to use a peripheral device such as a printer device in common. For example, a switching device is used to switch two computer devices to a side that uses peripheral devices such as a printer device.

FIG. 5 shows two computer devices 103.
A and 103B schematically show a use environment when one printer apparatus 110 having a USB-compatible interface is used. The mouse 101A is connected to the keyboard 100A. The keyboard 100A is connected to the computer device 103A via the input cable 102A. An image output from the computer device 103A is supplied to a monitor 105A via a video cable 104A. Computer device 103A and USB switching device 10
7 are connected via a USB cable 106A.
The connection on the computer device 103B side is the same as the connection on the computer device 103A side, and the description is omitted here.

[0006] To the USB switching device 107, USB cables 106A and 106B are connected.
08, the signal path by USB
It is possible to selectively switch between the B cable 106A side and the USB cable 106B side. USB switching device 10
8 and the printer device 110 are connected by a USB cable 109.

In such a configuration, the user can
By operating the external switch 108 provided on the B switching device 107, the computer devices 103A and 103A
One of B is selected. USB switching device 107
The signal output from the computer device selected by the external switch 108 is
Supplied to

FIG. 6 shows a conventional USB switching device 1.
07 is shown. The USB switching device 107 has a predetermined connector for a USB cable (not shown), and has a mechanical selector 122 that can be selected by an external switch 108. The selector 122
Connection of one and the other select terminals to the common terminal
Switching is performed by selecting a signal supplied from the external switch 108.

The printer device 110 has a USB function 121. The USB function 121 is
It is connected to a common terminal of the selector 122 via the USB cable 109. One selection terminal of the selector 122 is
Computer device 10 via USB cable 106A
It is connected to the 3A USB host controller 123A. Similarly, the other selection terminal of the selector 121 is US
Computer device 103B via B cable 106B
USB host controller 123B. U
The SB host controllers 123A and 124B are connected to the USB devices of the computer devices 106 and 109, respectively.
This is the part that controls the interface.

By operating the external switch 108 in a predetermined manner, the user can select one of the selection terminals and the other, and can select the desired one of the computer device 103A and the computer device 103B.

By the way, as described above, the USB is designed so that the connector can be inserted and removed even when the power of the host controller such as the computer device 103A or 103B is turned on. This will be described.

For example, suppose a case where a USB-compatible printer is connected and used with a USB cable in the computer apparatus 103A, and then the USB cable is connected from the printer to a USB-compatible scanner. Even in this case, the computer device 103A
Without manual initialization such as turning off the power of the computer or restarting the computer device 103A.
Connect the reconnected USB device to the computer 10
It can be used continuously from 3A.

To realize this, the computer device 103A loads device driver software corresponding to each USB device after it is recognized that the USB device is connected. Similarly, when the USB device is removed, the computer device 103A recognizes that the USB device has been removed, and then unloads the loaded driver software.

For example, when the computer 103A recognizes that a certain USB device is connected, for example, driver software corresponding to the USB device, which is stored in advance in a hard disk drive (HDD), is read from the HDD. The read driver software is developed on a memory such as a RAM (Random Access Memory). Thus, the driver software is loaded. Thereafter, exchange of data and control signals with the USB device is managed by the driver software developed on the memory.

Similarly, when the USB device is removed from the computer 103A, the driver software corresponding to the USB device, which has been expanded on the memory, is deleted from the memory, for example, and is discarded from the memory. Then, the driver software is unloaded. Next, when any USB device is connected, the corresponding driver software is loaded in the same manner.

As described above, when connecting and disconnecting a USB device, the computer device 103A performs a process of loading and unloading driver software corresponding to the USB device. That is, when removing the connected USB device and connecting another USB device, the device driver is unloaded and loaded. Although depending on the performance of the computer apparatus 103A, the procedure for loading / unloading the driver software usually requires several seconds.

[0017]

The prior art US
In the B switching device 107, as described above, the selector 122 that switches the USB signal path is configured by a mechanical switch. Therefore, each time the path is switched by the selector 122, disconnection and connection of the USB path are performed. Then, the driver software is loaded and unloaded. Therefore, the conventional USB switching device 107
When using the device, it takes several seconds from when the user operates the external switch 108 to switch the USB connection to when the switched USB device can be used, and the user is dissatisfied. There was a problem that it was very large.

Consider a case where the external switch 108 is operated again while the driver software is being loaded / unloaded by operating the external switch 108. As an example, it is assumed that the computer device 103A is initially selected in the selector 122. In this case, for example, while the driver software is being unloaded or loaded by the first operation of the external switch 108, the same driver software is unloaded. As a result, the computer device 103
In A, the load / unload processing of the driver software cannot be completed forever, and the computer device 103A
There is a problem that may hang up.

If the computer device 103A hangs up, it cannot be used again unless it is restarted. At this time, for example, if a working application such as document creation software is running on the computer device 103A, all data not stored in the HDD or the floppy (registered trademark) disk is lost. In addition, the time required for the restart means that the work is interrupted. These things are a great loss for the user.

Therefore, when the user wants to work while alternately switching between the computer devices 103A and 103B, the user needs to carefully perform the switching operation by the USB switching device 107 while paying attention to the situation of the driver loading process. There is a problem that it is very inconvenient to use and causes stress.

Further, in the conventional USB switching device 107, when one computer device is used,
When the external switch 108 is switched, an error occurs during printing and printing is not performed normally. Furthermore, not only printing is not performed normally, but also the computer device may hang up, which has been regarded as a problem.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a switching device and a method for easily switching a connection of a pluggable interface such as a USB, and an image display device.

[0023]

According to the present invention, in order to solve the above-mentioned problems, a plurality of information processing apparatuses can be connected so as to be hot-swappable and at least one electronic device can be connected. In a switching device configured to transfer data from one information processing device selected from a plurality of information processing devices to an electronic device, a plurality of connections for connecting the plurality of information processing devices via a hot-swappable bus Means,
Electronic device connecting means for connecting the electronic device, selecting means for selecting one of the plurality of information processing devices connected to the plurality of electronic device connecting means, and selecting by the selecting means among the plurality of information processing devices The data transfer is performed between the information processing device being connected to the electronic device connected to the electronic device connection means, and the information processing device that is not selected by the selection means among the plurality of information processing devices includes the electronic device. Control means for transmitting a signal indicating that data processing is being performed.

According to the present invention, a plurality of information processing apparatuses can be connected so as to be hot-swappable and at least one information processing apparatus can be connected.
In a switching method in which one electronic device is connectable and data is transferred from one information processing device selected from the plurality of information processing devices to the electronic device, a bus capable of hot-swapping the plurality of information processing devices is provided. Selecting one of the plurality of information processing devices connected from the plurality of electronic device connection steps, the plurality of connection steps for connecting via the PC, the electronic device connection step for connecting the electronic device, and the plurality of electronic device connection steps. And transferring the data between the information processing device selected by the selecting step of the plurality of information processing devices and the electronic device connected by the electronic device connecting step. The information processing device not selected by the selecting step includes a control step of transmitting a signal indicating that the electronic device is performing data processing. It is switching method characterized by.

According to the present invention, there is provided an image display device for displaying an image output from an information processing device, a plurality of connecting means for connecting the plurality of information processing devices via a hot-swappable bus, and Electronic device connecting means for connecting the devices, selecting means for selecting one of the plurality of information processing devices connected to the plurality of electronic device connecting means, and selecting means for selecting one of the plurality of information processing devices; The data transfer is performed between the information processing device that is connected to the electronic device connected to the electronic device connection means, and the information processing device that is not selected by the selection unit among the plurality of information processing devices is not A control unit for transmitting a signal indicating that the processing is being performed.

As described above, according to the first and sixth aspects of the present invention, one of the plurality of information processing apparatuses selected by the selection unit and the electronic equipment connected to the electronic equipment connection unit are provided. Between the plurality of information processing devices, the information processing device not selected by the selection unit is selected by the selection unit to transmit a signal indicating that the electronic device is performing data processing. Only the process from the selected information processing device is accepted, and the process from the information processing device not selected by the selection unit is not accepted.

According to a seventh aspect of the present invention, there is provided an image display apparatus for displaying data to be displayed based on an image signal output from an information processing apparatus, via a bus through which a plurality of information processing apparatuses can be hot-plugged. A plurality of connection units for connecting the electronic devices, an electronic device connection unit for connecting the electronic device, a selection unit for selecting one of the plurality of information processing devices connected to the plurality of electronic device connection units, and a plurality of Data transfer is performed between the information processing device selected by the selection unit among the information processing devices and the electronic device connected to the electronic device connection unit, and the data transfer is performed by the selection unit among the plurality of information processing devices. Since the information processing device does not have a control unit that transmits a signal indicating that the electronic device is performing data processing,
Space for the switching device can be saved.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of an example of a USB switching device 1 to which the present invention is applied. Note that the usage environment of the USB switching device 1 is the conventional technology shown in FIG.
It is assumed that the environment is the same as that described with reference to FIG. The printer device 2 has an interface corresponding to USB. For example, in FIG. 1, a printer device 2 is connected to a USB switching device 1 by a USB cable 3. The computer device 4A is connected to a USB cable 9A.
And the computer device 4B is connected to the USB switching device 1 by the USB cable 9B. Although not shown in FIG. 1, a monitor device is connected to each of the computer devices 4A and 4B.

A USB switching device 1 according to one embodiment of the present invention
Is a single USB host controller 12 and a plurality of USB functions 13 connected to each other via an internal bus 10.
A, 13B. USB function 13A, 1
3B is connected to, for example, each of the computer devices 4A and 4B, and driver software corresponding to the USB functions 13A and 13B is always loaded in the computer devices 4A and 4B.

Then, the USB function 13A, 1
Only the signal from the selected side of 3B is output to the USB host controller 12, and the signal from the non-selected side is not output to the USB host controller 12.
Switching of the computer devices 4A and 4B is performed. By doing so, the load / unload processing of the driver software does not occur in the computer devices 4A and 4B,
The switching of the SB signal can be performed smoothly.

The configuration of the USB switching device 1 will be described in more detail. In FIG. 1, in the USB switching device 1, a control unit 11, a USB host controller 12, and USB functions 13A and 13B are mutually connected by an internal bus 10. The USB host controller 12 controls exchange of data and control signals (USB signals) with USB devices via USB. Also, U
The SB functions 13A and 13B are USB devices themselves.

The control unit 11 is, for example, a CPU (Central Pro
cessing unit), an output from the external switch 14 is supplied, and a memory 15 is connected. The external switch 14 outputs a selection signal in accordance with an operation. The output of the USB signal by the USB functions 13A and 13B is controlled by the control unit 11 based on the selection signal, so that the user selects a desired one of the computer devices 6A and 6B connected to the USB switching device 1. can do.

The printer device 2 has a USB function 20. The USB function 20 and the USB host controller 12 are connected by the USB cable 3.

The computer devices 4A and 4B have USB host controllers 21A and 21B, respectively. In the example of FIG. 1, the USB function 13A of the USB switching device 1 and the USB host controller 21A of the computer device 4A are connected by a USB cable 9A. Similarly, the USB function 13B of the USB switching device 1 and the USB host controller 21B of the computer device 4B are connected by the USB cable 9B.

The input device 5A is connected to the computer device 4A via the input cable 8A, and the input device 5B is connected to the computer device 4B via the input cable 8B. Here, the input device 5A includes, for example, a keyboard 6A and a mouse 7A, and the input device 5B includes, for example, a keyboard 6B and a mouse 7B. The coordinate information and button press information (collectively referred to as mouse information) output from the mouse 7A are supplied to the keyboard 6A. Both the mouse information output from the mouse 7A and the key input information from the keyboard 6A are supplied to the computer device 4A via the input cable 8A. The input device 5B has the same configuration as the input device 5A, and thus the description is omitted here.

FIG. 2 shows a computer device 4A or 4A.
3 shows an example of the configuration of B. Computer devices 4A and 4
Since B can be realized by the same configuration, the computer device 4A will be described here as an example. The computer device 4A is, for example, a personal computer.
In the computer device 4A, the CPU 31, the hard disk drive (HDD) 3
3. The graphic board 34 and the USB host controller 21A are respectively connected. Also, the CPU 31
RAM (Random Access M) via the CPU bus 35
memory 3 such as emory) and ROM (Read Only Memory)
2 are connected.

Several types of USB driver software are stored in the HDD 33 in advance. The USB host controller 21A constantly monitors the connection of the USB device. When a USB-compatible device is connected to the USB controller 21A, the type of the connected USB device is checked. Based on the result, the driver software corresponding to the connected USB device is read from the HDD 33 under the control of the CPU 31. The read driver software is stored in the memory 32 via the CPU 31, and the driver software is loaded. The unloading of the driver software is performed, for example, by releasing the address of the loaded driver software on the memory 32 and discarding the address from the memory 32.

A display control signal is generated by the CPU 31 based on a predetermined program. The display control signal is supplied to the graphic board 34. The graphic board 34 generates and outputs an image signal based on the supplied display control signal. This image signal is supplied to a monitor device (not shown), and a predetermined display is made on a screen.

Next, the operation and processing in the above configuration will be described. First, the operation and processing of the USB switching device 1 at the time of startup by turning on power or the like will be described. It should be noted that the setup processing when the USB cable is connected in the USB switching device 1 has the same operation and processing.

The setup process in the USB standard will be schematically described. In the USB standard, a USB host controller on a computer device side and a specific USB
The communication procedure with the B function is started when the USB host controller issues a token packet indicating the USB function to communicate with and the transfer type. US specified in this token packet
The B function, based on the specified transfer type,
It communicates with the USB host controller.

When the apparatus is started (when power is turned on) or a USB cable is connected, information necessary for the operation of the USB device (such as a function and transfer type of the USB function to be connected) (referred to as a standard descriptor). ) Has not yet been notified to the USB host controller. Therefore, according to the USB standard, communication called control transfer is first performed by the USB host controller and the USB as a setup method at the time of startup or connection.
The USB host controller acquires the standard descriptor from the USB function.

The standard descriptor includes a device descriptor, a configuration descriptor, an interface descriptor, an endpoint descriptor, and a string descriptor.

FIG. 3 is a flowchart showing an example of a setup process according to the first embodiment when the USB switching device 1 is activated, for example. In FIG. 3, the computer device is abbreviated as “PC”.
First, in the first step S10, control transfer is performed between the USB host controller 12 and the USB function 20, and the standard descriptor of the USB function 20 is taken into the USB host controller 12. The captured standard descriptor of the USB function 20 is stored in the memory 15 connected to the control unit 11.
Is stored in

In the next step S11, one of the computer devices 4A and 4B (here, the computer device 4A) activates the USB switching device 1 and sends the
When the connection of the SB cable 9A is recognized, the USB host controller 21A of the computer device 4A sends the USB
Control transfer of the device descriptor is requested to the USB function 13A of the switching device 1.
This request is received by the USB function 13A,
It is sent to the control unit 11. In step S12, the control unit 11 responds to this request in step S10 described above.
The device descriptor is taken out of the standard descriptor of the USB function 20 stored in the memory 15 by the above processing, and returned to the USB host controller 21A of the computer device 4A via the USB function 13A.

In the next step S13, the control section 11 determines whether or not the processing in steps S11 and S12 has been performed on all the USB functions 13A and 13B of the USB switching device 1.

If it is determined in step S13 that all U
If it is determined that the process has not been performed on the SB functions 13A and 13B, the process proceeds to step S11.
To the next USB function 13B,
Similar processing is performed. Therefore, in the process for the USB function 13B, the device descriptor of the USB function 20 is returned to the USB host controller 21B of the computer device 4B via the USB function 13B, as in the case of the USB function 13A described above.

On the other hand, in step S13, all U
If it is determined that the process is being performed on the SB functions 13A and 13B, the process proceeds to step S14. In step S14, for example, in the computer device 4A, the device descriptor obtained in the process of step S12 is stored in the memory 32 by the CPU 31.

In the next step S15, for example, in the computer device 4A, the CPU 31
In step 14, the ID code is extracted from the device descriptor stored in the memory 32, and it is checked whether any of the driver software stored in the HDD 33 corresponds to the extracted ID code. If there is a corresponding driver software, the driver software is H
Read from the DD 33, read into the memory 32,
The driver software is loaded.

Although not shown, if there is no driver software corresponding to the ID code extracted from the device descriptor in step S15 in the HDD 33, for example, a display control signal for performing a predetermined display indicating this is sent to the CPU.
It is generated at 31, supplied to the graphic board, and displayed on a monitor (not shown) connected to the computer device 4A.

When the loading of the driver software is completed in step S15, the driver software is executed by the CPU 31 in step S16. At the beginning of the execution, the remaining part of the standard descriptor obtained in step S12 described above is loaded into the computer device 6A and stored in the memory 32A.
Is stored in The processing at this time is the same as that in step S
12 and S14.

For example, when the USB switching device 1 is started, the operation is enabled when the series of processing is completed.

When a device to be connected to the USB host controller 12 is determined in advance, a standard descriptor in the USB function of the device is previously stored in the memory 15 connected to the control unit 11. I just need. By doing so, the processing in step S10 of FIG. 10 described above can be omitted.

Next, the processing during the operation of the USB switching device 1 will be described. Here, an example in which the computer device 4A is selected in the USB switching device 1 will be described.

When printing is performed in the computer device 4A, transfer of print data from the USB host controller 21A to the USB function 13A via the USB cable 9A is started. USB function 1
The print data supplied to 3A is supplied to the control unit 11 via the internal bus 10, and is supplied to the USB host controller 12 via the internal bus 10. The print data supplied to the USB host controller 12 is transferred to the USB function 20 via the USB cable 3.
Printing is executed in the printer device 2 based on the print data supplied to the USB function 20. Thus, print data is transferred from the computer device 4A or 4B to the printer device 2.

On the other hand, when printing is executed in the computer device 4B that is not selected in the USB switching device 1 and the print data is supplied to the USB function 13B, the print data supplied to the USB function 13B by the control unit 11 Is not taken in, BUS
The Y signal is supplied to the USB host 21B. Where B
The USY signal is a signal indicating that the printer device 2 is processing. The computer device 4B is a BUSY
While the signal is being supplied, the print data transmission wait state is set. Thus, printing from the computer device 4B that is not selected in the USB switching device 1 can be prohibited.

By the above-described processing, a selection operation can be realized in which only the processing from the computer device selected by the USB switching device 1 is accepted, and the processing from the non-selected computer device is not received.

USB host 21 of computer device 4A
A to USB function 13A of USB switching device 1
While the print data is being transferred to the
4 is switched, the print data transfer process is maintained until the transfer of the print data from the USB host 21A is completed, and after the print data transfer process is completed, the selection or non-selection in the control unit 11 is performed. Is switched.

On the other hand, when a processing request is received from the computer device 4B while the data transfer process from the USB host 21A is maintained, a BUSY signal is supplied from the USB switching device 1 to the computer device 4B, and The processing request from the device 4B is not accepted by the USB switching device 1.

When the transfer of the print data from the USB host controller 21A to the printer device 2 is completed, the process of the computer device 4B is accepted by the USB switching device 1. During the process of the computer 4B, the process from the computer device 4A is performed. The BUSY signal is supplied to the computer device 4A in response to the processing request, and the processing request from the computer device 4A is not accepted. With the above-described processing, it is possible to prevent a printing error from occurring even when the external switch 14 is switched during printing.

If there is no data transfer from the computer device 4A or 4B to the printer device 2 for a certain period, the control section 11 determines that the data transfer has been completed.
Specifically, the USB data transfer is performed every 1 msec. Therefore, if there is no data transfer for 20 msec, the control unit 11 determines that the data transfer has been completed.

Alternatively, the control unit 11 monitors the data in the transfer data, and detects information such as the data size and the end code, so that the computer device 4A or 4
The end of data transfer from B to the printer device 2 may be determined. Specifically, in a USB printer, print data is transferred in a data format such as PDL (Page Description Language) or PCL (Printer Control Language). Of the computer device 4A or 4A by detecting information such as a data size and an end code from
It is determined that the data transfer from B to the printer device 2 has been completed.

When, for example, a request for the setting of the printer device 2 is supplied to the control unit 11 from the computer device 4B that is not selected in the USB switching device 1, the control unit 11 performs processing for this request. . More specifically, when a change in the settings of the printer device 2 is requested by control transfer, a request related to the settings of the printer device 2 is stored in the control unit 11. For example, the request is memory 1
5 is stored. After the computer device 4B is selected by the external switch 14, the controller 1
5, a request related to the settings of the printer device 2 is read and transferred to the printer device 2. Printer device 2
Is a request for changing the setting of the printer paper size, for example.

Next, a second embodiment of the present invention will be described. FIG. 4 shows a configuration of an example of the USB switching device 1 to which the present invention is applied. In the first embodiment, U
Although the example in which the printer device 2 is connected to the SB switching device 1 has been described, the second embodiment shows an example in which the scanner device 40 is connected to the USB switching device 1 '.
More specifically, the scanner device 40 has a USB function 41, and the USB function 41 and the USB host controller 12 are connected by the USB cable 3. In FIG. 4, the same reference numerals are given to the same parts as those in FIG. 1 described above, and detailed description will be omitted. Here, it is assumed that the usage environment of the USB switching device 1 'is the same as the environment described with reference to FIG.

The USB signals input to the USB host controller 12 are transmitted to the USB functions 13A and 13B.
The computer devices 4A and 4B are switched so as to output only from the selected side and not output from the non-selected side. In this way, the computer device 4
In A and 4B, the load / unload processing of the driver software does not occur, and the switching of the USB signal can be performed smoothly.

Hereinafter, a USB according to the second embodiment will be described.
The processing during the operation of the switching device 1 'will be described. In addition,
The setup process according to the USB standard is the same as that of the USB switching device 1 according to the above-described first embodiment, and a description thereof will not be repeated. Here, as an example, U
An example in which the computer device 4A is selected in the SB switching device 1 'will be described.

When an image capturing operation from the scanner device 40 is performed by an application in the computer device 4A, a data capturing start signal is transmitted from the USB host controller 21A to the USB function 13A. This signal is USB function 1
3A, and supplied to the control unit 11 via the internal bus 10. The signal supplied to the control unit 11 is
0 to the USB host controller 12. The signal supplied to the USB host controller 12 is transmitted to the USB function controller 4 via the USB cable 3.
Transferred to 1. Based on the signal transferred to the USB function 41, the scanner device 40 starts capturing image data.

The image data captured by the scanner device 40 is transmitted from the USB function 41 to the USB host controller 12 and supplied to the control unit 11 via the internal bus 10. The image data supplied to the control unit 11 is supplied to the USB function 13A via the internal bus 10 and is transmitted to the USB function 13A via the USB cable 9A.
The data is transferred to the host controller 21A. This allows
The image data captured by the scanner device 40 can be transmitted to the computer device 4A.

On the other hand, while an image is being captured by the computer device 4A, if an image capturing operation from the scanner device 40 is performed by an application of the computer device 4B not selected by the USB switching device 1 ', the USB host A data capture start signal is transmitted from the controller 21B to the USB function 13B. When this data capture start signal is received by the USB function 13B, the BU is
The SY signal is sent from the control unit 11 to the USB function 13B.
And transmitted to the USB host controller 21B. Here, the BUSY signal is a signal indicating that the scanner device 40 is processing. Note that the computer device 4B waits for data reception while the BUSY signal is being supplied. As a result, it is possible to prohibit an operation of taking in image data from a computer device not selected by the USB switching device 1 '.

By the above processing, the USB switching device 1 ′
In this case, a selection operation can be realized in which only processing from the selected computer device is accepted, and processing from the non-selected computer device is not accepted.

The external switch 14 is operated while the image data is being taken in the computer device 4A, and the computer device 4A transmits the image data to the computer device 4A.
When the selection is switched to B, the scanner device 40
The processing is maintained until the transfer of the image data from the computer to the computer device 4A is completed, and after the image data transfer processing is completed, the control unit 11 switches the signal path.

The scanner device 40 to the computer device 4
A while the image data is being transferred to A
4, while the transfer of image data from the scanner device 40 to the computer device 4A is maintained,
When there is a processing request from the computer device 4B to the USB switching device 1 ', a BUSY signal is transmitted from the USB switching device 1' to the computer device 4B, and the processing from the computer device 4B is not accepted.

From the scanner device 40 to the computer device 4
When the transfer of the image data to A is completed, a BUSY signal is supplied to the computer device 4A in response to a processing request from the computer device 4A that allows the process of the computer device 4B to be accepted by the USB switching device 1 ′,
The processing request from the computer device 4A is not accepted. According to the above-described processing, even when the external switch 14 is switched during the image capturing processing by the scanner device 40, it is possible to prevent an image data capturing error from occurring.

If there is no data transfer from the scanner device 40 to the computer device 4A or 4B for a certain period, the control unit 11 determines that the data transfer has been completed. Specifically, the USB data transfer is performed every 1 msec. Therefore, if there is no data transfer for 20 msec, the control unit 11 determines that the data transfer has been completed.

Alternatively, the control unit 11 monitors the data in the transfer data and detects information such as the data size and the end code to determine the end of the data transfer from the scanner device 40 to the computer device 4A or 4B. It may be.

When a request for changing the settings of the scanner device 40 is supplied to the control unit 11 from a computer device 4B that has not been selected, the control unit 11 performs processing relating to this request.
More specifically, when a change in the settings of the scanner device 40 is requested by control transfer, a request for a change in the settings of the scanner device 40 is stored in the control unit 11. For example, the request is stored in the memory 15. After the computer device 14B is selected by the external switch 14, a request for setting change of the scanner device 40 is read from the memory 15 and transferred to the scanner device 40. The request regarding the setting change of the scanner device 40 is, for example, a request regarding the setting change of the resolution.

Although the embodiment of the present invention has been specifically described above, the present invention is not limited to the above-described embodiment, and various modifications based on the technical idea of the present invention are possible. .

In the above-described embodiment, the configuration in which the two computer devices, that is, the computer device 4A and the computer device 4B are connected to the USB switching device 1 and the USB switching device 1 'has been described. Connect the device to USB switching device 1 and USB
It is also possible to adopt a configuration connectable to the switching device 1 '.

In the above-described embodiment, the printer device 2 and the scanner device 40 are used as electronic devices.
Although the configuration connected to the SB switching device 1 and the USB switching device 1 'has been described, an electronic device such as a digital camera or an MP3 that performs data transfer in response to a request from an application such as a computer device.
(MPEG-1 audio layer 3) Electronic devices such as players
It is also possible to adopt a configuration that is connected to the SB switching device 1 and the USB switching device 1 ′.

In the above embodiment, the US
Although the B switching device 1 and the USB switching device 1 'have been described as devices housed in independent housings, this is not limited to this example. The USB switching device 1 and the USB switching device 1 'can be incorporated in another device. For example, the USB switching device 1 and the USB switching device 1 'can be incorporated in a monitor device connected to the computer device 4A or 4B. This allows U
Space for the SB switching device 1 and the USB switching device 1 'is saved.

Further, in the above-described embodiment, the control unit 11 controls the computer 4A or 4B and the printer 2 or the scanner 4 based on the signal output in response to the operation of the external switch 14.
Although the configuration for controlling the data transfer to 0 has been shown, the control unit 11 controls the computer device 4A or the computer device 4B, the printer device 2 or the scanner device 40 based on the signal output from the computer device 4A or the computer device 4B. May be configured to control the data transfer. In other words, a configuration in which data transfer control is performed without the external switch 14 is also possible.

Further, the USB switching device 1 and the USB switching device 1 ′ described in the above-described embodiment can be implemented by the same configuration.

[0082]

As described above, according to the present invention, the computer device always uses the USB switching device U
The state where the driver software corresponding to the SB function is loaded is maintained. Therefore, there is an effect that the time required for loading and unloading the driver software at the time of switching can be saved, and there is an effect that hang-up due to switching timing can be prevented.

According to the present invention, data transfer is performed between the computer device selected in the USB switching device and the electronic device, and the information processing device not selected in the USB switching device includes the electronic device. Since we send a signal indicating that data is being processed,
It is possible to prevent a data transfer error occurring when the USB switching device is switched when using the electronic device.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an example of a USB switching device to which the present invention has been applied.

FIG. 2 is a block diagram illustrating a configuration of an example of a computer device.

FIG. 3 is a flowchart illustrating an example of a setup process when a USB switching device is activated.

FIG. 4 is a block diagram illustrating a configuration of an example of a USB switching device according to a second embodiment;

FIG. 5 is a schematic diagram schematically showing a use environment when one printer device is used by two computer devices via a USB switching device.

FIG. 6 is a block diagram illustrating a configuration of an example of a conventional USB switching device.

[Explanation of symbols]

1 ... USB switching device, 2 ... Printer device, 3 ...
..USB cable, 4A, 4B: computer device, 5: input device, 6A, 6B: keyboard,
7A, 7B ... mouse, 8A, 8B ... input USB
Cable, 9A, 9B ... USB cable, 10 ...
-Internal bus, 11 ... control unit, 12 ... USB host controller, 13A, 13B ... USB function, 14 ... external switch, 15 ... memory,
20 ... USB function, 21A, 21B ...
・ USB host controller

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B014 HA07 5B069 AA01 BA01 BA04 JA01 JA02 KA02 LA02 5B077 BB05 HH01 NN02 5C025 AA30 BA14 BA18 BA21 BA27 DA08

Claims (11)

[Claims] A plurality of information processing devices are connectably connectable to hot-swap, and at least one electronic device is connectable, and an electronic device is connected to one of the information processing devices selected from the plurality of information processing devices. A switching device configured to perform data transfer to a device; a plurality of connection means for connecting a plurality of information processing devices via a hot-swappable bus; an electronic device connection means for connecting an electronic device; Selecting means for selecting one of the plurality of information processing apparatuses connected to the plurality of connecting means; and connecting the information processing apparatus selected by the selecting means to the electronic apparatus among the plurality of information processing apparatuses Means for transferring data to and from an electronic device connected to the information processing means, wherein the information processing apparatus which is not selected by the selection means among the plurality of information processing apparatuses is the electronic equipment. Vessel switching device, characterized in that it comprises a control means for transmitting a signal indicating that data is being processed. 2. The switching device according to claim 1, wherein the bus is hot-swappable, and information necessary for operation of a device connected to one of the buses is connected to the other of the buses. The information processing device obtains the information so that the device can be controlled by the information processing device, and discards information necessary for the operation of the device when the device is not connected. A switching device, which is a route. 3. The switching device according to claim 1, wherein the bus is a USB. 4. The switching device according to claim 1, wherein the control unit, when the selection of the information processing device is changed by the selection unit during the data transfer, after the completion of the data transfer. A switching device, wherein data transfer is performed between the information processing device to which the selection is changed by the selection means and the electronic device. 5. The switching device according to claim 1, wherein the control unit is configured to change a setting of the electronic device from an information processing device that is not selected by the selection unit among the plurality of information processing devices. A switching device, wherein when a request is received, the request is stored, and the request is transmitted to the electronic device after the information processing device that has transmitted the request is selected by the selection unit. 6. A plurality of information processing devices are connectable so as to be hot-swappable, and at least one electronic device is connectable. In a switching method for performing data transfer to a device, a plurality of connection steps for connecting a plurality of information processing devices via a hot-swappable bus, and an electronic device connection step for connecting the electronic device A step of selecting one of the plurality of information processing devices connected by the plurality of electronic device connection steps; and a step of selecting one of the plurality of information processing devices by the selection step. Data transfer between the information processing device and the electronic device connected in the step of connecting the electronic device. Switching method characterized by the above-mentioned information processing apparatus which is not selected by the selection step and a step of controlling to transmit a signal indicating that the electronic device is in data processing. 7. An image display device for displaying data to be displayed by an image signal output from an information processing device, comprising: a plurality of connection means for connecting the plurality of information processing devices via a hot-pluggable bus; An electronic device connection unit for connecting the electronic device; a selection unit for selecting one of the plurality of information processing devices connected to the plurality of electronic device connection units; Data transfer is performed between the information processing device selected by the selection means and the electronic device connected to the electronic device connection means, and data transfer is performed by the selection means among the plurality of information processing devices. An image display device, wherein the information processing device includes a control unit that transmits a signal indicating that the electronic device is performing data processing. 8. The image display device according to claim 7, wherein the bus is hot-swappable, and information necessary for operation of a device connected to one of the buses is connected to the other of the buses. Acquired by the information processing device obtained, it is possible to control the device by the information processing device, and to discard information necessary for the operation of the device when the device is not connected An image display device, which is a communication path. 9. The image display device according to claim 7, wherein the bus is a USB. 10. The image display device according to claim 7, wherein the control unit, after changing the selection of the information processing device by the selection unit during the data transfer, after the data transfer is completed. An image display device, wherein data transfer is performed between the information processing device to which the selection is changed by the selection means and the electronic device. 11. The image display device according to claim 7, wherein the control unit changes a setting of the electronic device from an information processing device that is not selected by the selection unit among the plurality of information processing devices. Receiving the request of (1), storing the request, and transmitting the request to the electronic device after the information processing apparatus that has transmitted the request is selected by the selection unit. apparatus.