JP2008134675A - Computer, projector system, and data communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a computer capable of displaying the most suitable image for the communication speed of an external device. <P>SOLUTION: The computer includes a communication part 11 designed to be capable of switching a communication speed between a first communication speed and a second communication speed higher than the first communication speed, when executing data communication with an external device; a control part 12 that sends image data Dg to the external device via the communication part 11; and a USB controller 11b for detecting whether the communication speed of the external device is the first or second communication speed. When the detected communication speed of the external device is the first communication speed, the control part 12 sends the image data Dg in a compressed state at the first communication speed; when the communication speed of the external device is the second communication speed, the control part 12 sends the image data Dg at the second communication speed while keeping the data uncompressed or compressing it to a lesser degree than the compressed state. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a computer that transmits image data to an external device, a projector system that includes the computer and a projector, and a data communication method that transmits image data to an external device.

As this type of projector system, a projector system disclosed by the applicant in Japanese Patent Application Laid-Open No. 2004-69997 is known. This projector system includes a PC (personal computer) and a projector connected via a USB cable. In this projector system, a PC transfers image data to a projector via a USB cable in accordance with a USB communication procedure (protocol) compliant with the USB 2.0 standard, for example, and the projector projects and displays an image based on the transferred image data.
JP-A-2004-69997 (pages 8-12, FIG. 1)

  However, the projector system has the following problems to be improved. That is, in this projector system, the PC transfers image data to the projector according to the USB communication procedure. Here, the USB communication procedure includes a USB 1.1 standard in which two modes, a low-speed mode with a communication speed of 1.5 Mbps and a full-speed mode with a communication speed of 12 Mbps, and the USB 1.1 standard are defined. There are two types of standards, the USB 2.0 standard, which is an upward compatible standard and that defines a Hi-Speed mode with a communication speed of 480 Mbps. In this case, for example, in a projector system in which a PC includes a communication unit conforming to the USB 2.0 standard and a projector includes a communication unit conforming to the USB 1.1 standard, it is assumed that data is transmitted from the PC at 480 Mbps. In addition, when large image data is created and transmitted, reception of the image data by the projector is severely delayed, and there is a problem that smooth image display becomes difficult. In this case, a method of compressing image data at a PC and transmitting the compressed image data at a communication speed of 1.5 Mbps or 12 Mbps can be considered regardless of the USB standard on the projector side. However, in this method, when a projector having a communication unit compliant with the USB 2.0 standard is connected to this PC, a compressed image is obtained even though data communication at a high communication speed is possible. There is a problem that only low-quality images can be displayed when data is transmitted. Further, a method of changing the communication speed on the PC side and whether or not to compress the image data by switching operation in accordance with the communication speed on the projector side is also conceivable. However, this method has a disadvantage that the switching operation is complicated and it is necessary to check in advance which of the two types of USB standards the communication unit of the projector complies with.

  The present invention has been made in view of the points to be improved, and it is a main object of the present invention to provide a computer, a projector system, and a data communication method capable of displaying an optimal image according to the communication speed of an external device. .

  In order to achieve the above object, the computer according to the present invention can switch the communication speed when executing data communication with an external device to the first communication speed and the second communication speed higher than the first communication speed. A computer configured to transmit the image data to the external device via the communication unit, wherein the communication speed of the external device is the first communication speed and the second communication speed. A detection unit that detects which one of the communication speeds, and the control unit is configured to compress the image data when the communication speed of the external device detected by the detection unit is the first communication speed. When the communication speed of the external device is the second communication speed, the image data is uncompressed or in a lower compression state than the compressed state. To be transmitted at a speed.

  Further, the data communication method according to the present invention is configured such that the communication speed when executing data communication with an external device can be switched between the first communication speed and the second communication speed higher than the first communication speed. A data communication method for transmitting image data to the external device via the communication unit that detects whether the communication speed of the external device is the first communication speed or the second communication speed; When the detected communication speed of the external device is the first communication speed, the image data is compressed and transmitted at the first communication speed. When the communication speed of the external device is the second communication speed, the image is transmitted. Data is transmitted at the second communication speed in an uncompressed state or in a compressed state lower than the compressed state.

  According to the computer and the data communication method, when the communication speed of the external device is detected and the communication speed is the first communication speed, the image data is compressed and transmitted at the first communication speed. By transmitting the image data at the second communication speed in the uncompressed state or in the low compression state at the second communication speed, the image data having a small data size that does not cause an obstacle to reception when the communication speed of the external device is low. When the communication speed of the external device is high, image data with a large data size that can display a high-quality image can be transmitted. Therefore, according to the computer and the data communication method, it is possible to display an optimal image corresponding to the communication speed of the external device. Further, the communication unit detects the communication speed of the external device, and the control unit determines the compression state (compressed, uncompressed and low compression) of the image data and controls the communication speed based on the detection result. As a result, it is possible to omit a complicated switching operation and an operation for preliminarily checking a communication speed (a type of communication procedure standard) in the external device. As a result, operability can be sufficiently improved.

  In the computer according to the present invention, the communication unit performs data communication according to a USB communication procedure.

  According to this computer, since the communication unit performs data communication according to the USB communication procedure, the USB communication procedure is a highly versatile communication procedure adopted in many devices (external devices). It can be realized in combination with many devices.

  A projector system according to the present invention is a projector system including the above computer and the projector as the external device capable of executing data communication with the communication unit of the computer. The compression state of the received image data is determined, and data processing corresponding to the determination result is performed on the image data.

  According to this projector system, since the projector and the projector as an external device capable of executing data communication between the computer and the communication unit of the computer are provided, the projector can compress the received image data. And processing the data according to the determination result, the image data transmitted from the computer is based on the image data regardless of whether the image data is in a compressed state, an uncompressed state, or a low-compressed state. An image can be reliably projected and displayed.

  The best mode of a computer, a projector system, and a data communication method according to the present invention will be described below with reference to the accompanying drawings. A projector system 1 shown in FIG. 1 is an example of a projector system according to the present invention. As shown in FIG. 1, a computer 2, a projector 3 (external device in the present invention), and a computer 2 and a projector 3 are connected. USB cable 200 is provided. The computer 2 is an example of a computer according to the present invention. As shown in FIG. 3, the computer 2 includes a communication unit 11, a control unit 12, a hard disk drive 13, a RAM 14, an operation unit 15, a VRAM 16, a graphic controller 17, a display 18, and A bus 19 for connecting these components is provided.

  The communication unit 11 is an interface compliant with the USB (Universal Serial Bus) 2.0 standard, and includes a connector 11a and a USB controller 11b as shown in FIG. 3, and performs data communication according to a USB communication procedure. As shown in FIG. 1, the connector 11 a is configured so that a plug-in side (male side) connector 201 of the USB cable 200 can be connected. The USB controller 11b executes transmission / reception (communication) of various data such as image data Dg to and from an external device (in this example, the projector 3) via the USB cable 200 connected to the connector 11a. The USB controller 11b functions as a detection unit in the present invention, and detects whether the USB standard of the projector 3 connected via the USB cable 200 is the USB 1.1 standard or the USB 2.0 standard.

  The control unit 12 executes various processes according to various computer programs and controls each component constituting the computer 2. In addition, the control unit 12 transmits image data Dg to the projector 3 via the USB cable 200 by executing an image data transmission process 50 described later. In this case, the controller 12 compresses the image data Dg based on the detection result of the USB standard detected by the USB controller 11b of the communication unit 11 when the image data transmission process 50 is executed. Alternatively, it is determined whether or not to be in an uncompressed state, and the image data Dg in any state is transmitted. The hard disk drive 13 stores various computer programs such as an operating system, a graphical device interface, a display driver, a projector driver, a mouse driver, a keyboard driver, and an application program.

  The RAM 14 is a system memory and temporarily stores various computer programs stored in the hard disk drive 13. The RAM 14 stores the image data Dg written by the control unit 12 in the image data storage area. The operation unit 15 includes, for example, a keyboard 15a and a mouse 15b (both see FIG. 1). In this case, the keyboard 15a and the mouse 15b output an operation signal So corresponding to the operation. The VRAM 16 stores image data Dg written by the control unit 12. The graphic controller 17 causes the display 18 to display an image based on the image data Dg stored in the VRAM 16. The display 18 is composed of, for example, an LCD (liquid crystal display).

  On the other hand, the projector 3 is an example of a projector according to the present invention, and projects and displays an image based on the image data Dg by projecting the projection light L onto the screen 100 (see FIG. 4). Specifically, as shown in the figure, the projector 3 includes a communication unit 21, a control unit 22, a ROM 23, a frame data processing unit 24, an operation unit 25, a projection unit 26, a light source power supply unit 27, and respective elements thereof. And a bus 28 for connecting the two. The communication unit 21 is an interface compliant with the USB standard (either the USB 1.1 standard or the USB 2.0 standard), and includes a connector 21a and a USB controller 21b. As shown in FIG. 2, the connector 21 a is configured so that the plug-in side connector 201 of the USB cable 200 can be connected. The USB controller 21b executes transmission / reception of various data such as image data Dg to / from an external device via the USB cable 200 connected to the connector 21a.

  The control unit 22 executes various processes according to the operation program and controls each component constituting the projector 3. Further, the control unit 22 controls the projection unit 26 to execute projection light L for image display by executing an image display process 60 described later. In this case, the control unit 22 specifies the data format (compressed and uncompressed) of the image data Dg transmitted from the computer 2 when executing the image display process 60, and performs data processing according to the result as frame data. The processing unit 24 executes the processing. The ROM 23 stores an operation program for the control unit 12, driving data for each component, and the like.

  The frame data processing unit 24 generates frame data Dr based on the image data Dg transmitted from the computer 2. The operation unit 25 includes various switches and keys such as a power switch, a zoom adjustment key, and a keystone correction key, and outputs an operation signal So when these are operated. As shown in FIG. 4, the projection unit 26 includes a light source 26a, a liquid crystal light valve 26b, and a projection lens 26c. The projection light L is light-modulated based on the frame data Dr generated by the frame data processing unit 24. Is projected. The light source power supply unit 27 supplies power to the light source 26 a of the projection unit 26 under the control of the control unit 12.

  Next, the overall operation of the projector system 1 will be described with reference to the drawings. First, the keyboard 15a and the mouse 15b are operated to cause the computer 2 to start an application program. At this time, the control unit 12 reads the application program from the hard disk drive 13 according to the operation signal So from the keyboard 15a and the mouse 15b, stores the application program in the RAM 14, and executes the process according to the application program. In this case, the control unit 12 stores the image data Dg generated by the application program in the VRAM 16. Further, the graphic controller 17 causes the display 18 to display an image based on the image data Dg stored in the VRAM 16.

  Next, when the image generated by the application program is projected and displayed on the screen 100 using the projector 3, the plug-in side connector 201 of the USB cable 200 is connected to the connector 11a of the computer 2 as shown in FIGS. And into the connector 21a of the projector 3, respectively. At this time, the USB controller 11 b of the communication unit 11 connects the communication unit 11 and the communication unit 21 of the projector 3 via the USB cable 200 based on the potential of the signal line among the lines constituting the USB cable 200. And the projector 3 detects whether the USB standard of the projector 3 is the USB 1.1 standard or the USB 2.0 standard.

  Next, the projection display program is started by operating the keyboard 15a and the mouse 15b. At this time, the control unit 12 executes an image data transmission process 50 shown in FIG. 5 according to the projection display program. In the image data transmission process 50, the control unit 12 first executes a transmission data generation process (step 51). In this case, as an example, the control unit 12 acquires the image data Dg generated by the running application program as it is (for example, in the state of RAW data) and stores it in the RAM 14. Subsequently, the control unit 12 determines whether the image data Dg is in a compressed state or an uncompressed state based on the detection result by the USB controller 11b of the communication unit 11. Specifically, the control unit 12 determines whether or not the USB standard of the projector 3 is the USB 1.1 standard (step 52). At this time, when the control unit 12 determines that the USB standard is the USB 1.1 standard, the control unit 12 also determines whether the mode is the low-speed mode or the full-speed mode.

  Here, when it is determined that the USB standard of the projector 3 is the USB 1.1 standard and the mode is the full-speed mode, the control unit 12 executes a compression process on the image data Dg stored in the RAM 14. (Step 53). In this case, as an example of the compression process, the control unit 12 converts the image data Dg into a JPEG (Joint Photographic Experts Group) format by irreversible compression (lossy compression). Subsequently, the control unit 12 controls the USB controller 11b of the communication unit 11 to transmit the compressed JPEG format image data Dg at the communication speed (12 Mbps) of the USB 1.1 standard Full-Speed mode (step 54). ). Further, when the control unit 12 determines in step 52 that the USB standard of the projector 3 is the USB 1.1 standard and the mode is the low-speed mode, the control unit 12 compresses the image data Dg higher than in the full-speed mode. The image data Dg is transmitted at the communication speed (1.5 Mbps) in the Low-Speed mode of the USB 1.1 standard (step 54). If the control unit 12 determines in step 52 that the USB standard of the projector 3 is the USB 2.0 standard, the control unit 12 controls the USB controller 11b of the communication unit 11 to store the image data Dg stored in the RAM 14 as it is. In this state (non-compressed state), the data is transmitted at a USB 2.0 standard communication speed (480 Mbps) (step 55).

  On the other hand, in the projector 3, the control unit 22 controls the light source power supply unit 17 according to the operation program stored in the ROM 23 to supply power to the light source 26 a of the projection unit 26. Moreover, the control part 22 performs the image display process 60 shown in FIG. 6 according to an operation program. In the image display process 60, the control unit 22 determines whether or not the communication unit 21 has received the image data Dg (step 61). In this case, when it is determined that the communication unit 21 has not received the image data Dg, the control unit 22 repeatedly executes step 61. On the other hand, when the communication unit 21 determines that the image data Dg has been received, the control unit 22 determines whether the image data Dg is in JPEG format, that is, whether the image data Dg is in a compressed state or an uncompressed state ( Step 62).

  In this case, when the control unit 22 determines that the image data Dg is in JPEG format, that is, in a compressed state, the control unit 22 controls the frame data processing unit 24 to execute data processing based on the JPEG format image data Dg. As a result, frame data Dr is generated (step 63). On the other hand, when it is determined that the image data Dg is not in the JPEG format, that is, in the uncompressed state, the control unit 22 controls the frame data processing unit 24 and is based on the image data Dg in the uncompressed state (RAW format). The frame data Dr is generated by executing data processing (step 64). Next, the liquid crystal light valve 26b of the projection unit 26 modulates the light from the light source 26a into the projection light L based on the frame data Dr. At this time, the projection light L is projected while being enlarged toward the front of the projector 3 through the projection lens 26c. Thereby, an image based on the image data Dg is projected and displayed on the screen 100.

  Thus, according to the computer 2, the projector system 1, and the data communication method, when the USB standard in the projector 3 is the USB 1.1 standard, the compressed image data Dg is transmitted at the communication speed of the USB 1.1 standard. When the USB 2.0 standard is used, the uncompressed image data Dg is transmitted at the communication speed of the USB 2.0 standard, so that when the communication speed of the projector 3 is low, the image data Dg having a small data size that does not interfere with reception can be obtained. When the transmission speed is high, image data Dg having a large data size capable of displaying a high-quality image can be transmitted. Therefore, according to the computer 2, the projector system 1, and the data communication method, an optimal image corresponding to the communication speed of the projector 3 can be displayed. Further, the communication unit 11 detects the USB standard type of the projector 3, and the control unit 12 performs compression and non-compression of the image data Dg and control of the communication speed based on the detection result, so that complicated switching is performed. As a result of omitting the operation and the work of checking the USB standard type in the projector 3 in advance, the operability can be sufficiently improved. Further, according to the projector system 1, the projector 3 determines the compression state of the received image data Dg and performs data processing according to the determination result, whereby the image data Dg transmitted from the computer 2 is obtained. Regardless of the compressed state or the uncompressed state, it is possible to reliably project and display an image based on the image data Dg.

  Further, according to the computer 2, since the communication unit 11 that performs data communication according to the USB communication procedure is provided, the USB communication procedure is a highly versatile communication procedure adopted in many devices (external devices). Therefore, the above-described effects can be realized in combination with many devices.

  In addition, this invention is not limited to said structure. For example, although the example provided with the communication unit 11 compliant with the USB standard has been described above, the present invention is not limited to this, and a computer including various communication units that perform data communication according to a communication procedure having a plurality of standards having different communication speeds. Can be applied. Further, the present invention can be applied to a computer including a communication unit that performs wireless communication with this type of communication procedure without using a cable.

  In addition, the example in which the image data Dg is converted to the JPEG format by irreversible compression (lossy compression) in the compression processing has been described above. It is also possible to adopt a configuration for converting to other types such as (Graphics Interchange Format) format or PNG (Portable Network Graphics) format. Further, the example in which the image data Dg is transmitted in an uncompressed state when the USB standard of the projector 3 is the USB 2.0 standard has been described above. At this time, the image data Dg has a lower compression rate than the JPEG format (low compression). It is also possible to adopt a configuration in which the state is converted into a model (for example, the above-described GIF format or PNG format).

  Further, the example in which the image data Dg is transmitted to the projector 3 as an external device has been described above, but the external device in the present invention includes various devices such as a CRT, a liquid crystal display panel, and a plasma display, and these devices include a computer. When the image data Dg is transmitted from 2, the same effect as the above can be realized.

1 is a configuration diagram showing a configuration of a projector system 1. FIG. It is the perspective view which looked at the projector 3 from the back side. 2 is a block diagram showing a configuration of a computer 2. FIG. 2 is a block diagram showing a configuration of a projector 3. FIG. 5 is a flowchart of an image data transmission process 50. 5 is a flowchart of an image display process 60.

Explanation of symbols

  1 projector system, 2 computers, 3 projectors, 11, 21 communication unit, 11b USB controller, 12, 22 control unit, Dg image data

Claims (4)

A communication unit configured to be able to switch a communication speed when executing data communication with an external device between a first communication speed and a second communication speed higher than the first communication speed; A computer having a control unit for transmitting image data to the external device,
A detection unit that detects whether the communication speed of the external device is the first communication speed or the second communication speed;
When the communication speed of the external device detected by the detection unit is the first communication speed, the control unit transmits the image data in a compressed state at the first communication speed, and the communication speed of the external device is A computer that transmits the image data at the second communication speed in an uncompressed state or at a lower compression state than the compressed state at the second communication speed.   The computer according to claim 1, wherein the communication unit performs data communication according to a USB communication procedure. A projector system comprising: the computer according to claim 1; and a projector as the external device capable of executing data communication between the communication unit of the computer.
The projector system determines a compression state of the received image data and performs data processing on the image data according to the determination result. Via the communication unit configured to be able to switch the communication speed when executing data communication with the external apparatus to the first communication speed and the second communication speed higher than the first communication speed, A data communication method for transmitting image data,
It is detected whether the communication speed of the external device is the first communication speed or the second communication speed, and the image data is compressed when the detected communication speed of the external device is the first communication speed. The second communication speed is transmitted at the first communication speed in the state, and when the communication speed of the external device is the second communication speed, the image data is in an uncompressed state or in a lower compression state than the compressed state. Data communication method to send in.

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