JPH11212521A - Picture display system and picture display method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a picture display system and a picture display method where a display picture is quickly changed even in the case of display of a picture transferred by communication at a low transfer rate. SOLUTION: The change of a picture is detected in every frame by a motion detection part 100, and changed picture data and its position information are outputted in accordance with the detection result by an output control part 200, and outputted picture data and position information are transmitted from a transmitter 300 to an FLCD(ferroelectric liquid crystal) display unit 400 by wireless transmission. In the FLCD display unit 400, a picture where only a part corresponding to transmitted data is changed is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image display system and an image display method, for example, an image display system and an image display method for displaying an image signal transmitted at a predetermined rate.

[0002]

2. Description of the Related Art In recent years, flat panel displays using liquid crystal or the like have attracted attention as display device technologies. Flat panel displays are used for laptops, notebooks,
Not only computers but also monitors for desktop computers are expected to be widely used in place of CRTs in the future because of their compactness and extremely low emission of electromagnetic waves.

As one of such flat panel displays, a display using a ferroelectric liquid crystal (FLC) (hereinafter abbreviated as FLCD) has been put to practical use. The FLC has a property called a memory property (a property that the ON / OFF state of the liquid crystal is maintained even when an electric field required for switching is removed), and it is very difficult to use the FLC with the conventional liquid crystal technology. A large-screen flat display can be realized. That is, an efficient refresh operation of the screen can be performed by performing a partial rewrite scan in which a line in which image data to be displayed has changed is selected and scanned preferentially on the display. Accordingly, even if the upper limit frequency of the entire frame rewriting (hereinafter simply referred to as “frame frequency” for simplicity) tends to decrease due to an increase in the number of display lines accompanying the increase in the size and definition of the display, a sufficient computer screen can be obtained. Response speed can be realized.

[0004] On the other hand, computer technology has come to exhibit multiple functions organically by fusing it with networking technology and various peripheral devices. Above all, the application of wireless communication technology enables cordless data transfer without cable connection between devices, improving the portability of computers and the degree of freedom of computer device arrangement. At present, most notebook computers use IrDA (Infrared Data Associati).
on), and is applied to data communication between computers and personal digital assistants (PDAs) and data transfer to printers. In addition, the 2.4 GHz band ISM (Industrial Scient
Wireless LAN systems using SS (Spectrum Spread) technology and high-speed infrared transmission technology in the ific medical) band have also been commercialized. These are attracting attention as means for solving various problems such as the complexity of the wiring plan accompanying the LAN cable wiring, prolonged wiring work, and the cost of wiring. Further, transmission of computer image data by wireless communication has been attempted for the purpose of eliminating troublesome cable wiring and improving the degree of freedom of wiring between a computer main body and a display.

[0005]

However, in the above-mentioned conventional wireless data communication, a transmission capacity of about 1 Gbps is required at the resolution of XGA, whereas the transmission capacity at the current practical level is a radio wave of 5 Mbps. , The infrared light is as low as 10 Mbps. Therefore, when a computer image is transmitted by the conventional wireless data communication, the image data is updated only about once every few seconds, and it becomes like a picture-story show. For example, a sufficient response to mouse movement cannot be obtained. Was. Thus, it has not been practical to transfer a computer image such as XGA to a display by conventional wireless communication.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an image display system and an image display system capable of updating a display image at high speed even when displaying an image transferred by communication with a low transfer rate. It is intended to provide a display method.

[0007]

As a means for achieving the above object, a display control device of the present invention has the following arrangement.

That is, image input means for inputting an image signal on a frame basis, motion detecting means for detecting a change in an image for each frame, and output of changed image information in accordance with a detection result by the motion detecting means. Output control means,
The communication device includes a communication unit that transmits the image information output by the output control unit, and a display unit that displays an image based on the data transmitted by the communication unit.

For example, the display means is a ferroelectric liquid crystal display.

[0010] For example, the display means updates an image portion corresponding to the data transmitted by the communication means and displays an image.

For example, the communication means transmits image information by wireless communication.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below in detail with reference to the drawings.

<First Embodiment> FIG. 1 is a block diagram showing the configuration of a display control device according to this embodiment. In the figure, 10 is a video signal input terminal, 20 is an image synchronization signal input terminal, 30 is a control signal input terminal, 40 is a video amplifier, and 50 is an analog / digital converter (hereinafter referred to as “A”).
/ D converter ”), 60 is a synchronization separation circuit. Reference numeral 70 denotes a clock generation unit having an arbitrary frequency, and a phase comparator (hereinafter, “PLL”) incorporating a charge pump type low-pass filter.
71, voltage controlled signal oscillator (hereinafter, “VCO”) 7
2, and a frequency divider 73. 80 is a system control unit, 100 is a motion detection unit, 200 is an output control unit, 300
Is a transmitter. Reference numeral 400 denotes a display unit using an FLCD, 500 denotes a receiver, and 600 denotes a display control unit.

The video signal input from the video signal input terminal 10 is amplified by a video amplifier 40 and converted to a digital video signal s20 by an A / D converter 50.

The image synchronizing signal input from the image synchronizing signal input terminal 20 is synchronized with the video signal, and is input to the synchronizing separation circuit 60 to be separated into a horizontal synchronizing signal s30 and a vertical synchronizing signal s40. These signals are input to the system control unit 80, the motion detection unit 100, and the output control unit 200, and the horizontal synchronization signal s30 is input to the clock generation unit 70.

The clock generation unit 70 includes a system control unit 8
The frequency dividing value s60 by 0 is set in the frequency divider 73, and the PLL7
1 and the VCO 72 generate a dot clock s50 obtained by multiplying the horizontal synchronizing signal s30. Dot clock s50 is
While being supplied to the A / D converter 50 as a sampling clock, the motion detection unit 100 and the output control unit 20
Input to 0.

Next, the processing in the system control unit 80 will be described with reference to the flowchart of FIG. First s
At t20, the image synchronization signal input terminal 20 shown in FIG.
Horizontal synchronization signal s30 and vertical synchronization signal s4 input from
The frequency of 0 is measured and their polarities are determined, and the display mode of the input video signal is identified. And st
At 30, the control parameters s60, s70, and s80 are set in the clock generator 70, the motion detector 100, and the output controller 200 based on the display mode identification result. Also,
Based on the control signal inputted from the control signal input terminal 30, the control parameters are changed, various processes are controlled, and the state of the transmitter 300 is checked.

Next, an example of the detailed configuration of the motion detecting section 100 will be described with reference to FIG. In the figure, 110 is an image conversion circuit for performing image compression optimized for motion detection, 120 and 130 are changeover switches, and 140 is image compression data s
This is a frame buffer that stores 110 for two frames. Reference numeral 150 denotes a valid data discriminating circuit;
2 is a counter, 153 and 154 are comparison circuits, 155 is a logical product circuit, and 160 is a comparison circuit for comparing compressed image data between frames.

The digital image data s20 input to the motion detection unit 100 is image-compressed by the image conversion circuit 110 and sent to the frame buffer 140 via the switch 120. Here, the switch 120 and the switch 130 switch the frame buffer 140 based on the control signal s70.
Buf. 1 and Buf. 2 is exclusively selected. For example, the Bu of the frame buffer 140 is
f. 1 is selected, the switch 130 sets the Buf. Select 2. Thereby, for example, the latest compressed image data s110 sent
Buf. 1, Buf. Corresponding to the display content of the FLCD display unit 400 is input. The second compressed image data s120 is sent to the comparison circuit 160.

In the valid data discriminating circuit 150, the input horizontal synchronizing signal s30 and dot clock s50 are counted by the counters 151 and 152. Here, the comparison circuits 153 and 154 include the system control unit 80
Control parameter s7 based on the display mode identification result by
A predetermined value is set by 0, and the valid display area is determined by comparing the predetermined value with the above-mentioned count value. The valid display area signal s130 output from the valid data determination circuit 150 is input to the image conversion circuit 110, the frame buffer 140, and the comparison circuit 160, and activates these circuits when the area is a valid display area. The counters 151 and 152 are reset by the active signals of the vertical synchronization signal s40 and the horizontal synchronization signal s30, respectively.

In the comparison circuit 160, the latest compressed image data s110 and the compressed image data s120 corresponding to the display image of the FLCD display unit 400 are displayed.
When the result is equal to or greater than the threshold value s70 set by the system control unit 80, it is determined that a change has occurred in the image, and the image change signal s10 is provided for each horizontal display line.
Outputs 0. The image change signal s100 is output from the output control unit 2
00, and also to the system control unit 80. The system control unit 80 synchronizes with the vertical synchronization signal s40 when an image change occurs, and
The control parameter s70 is set so that the switch 120 and the switch 130 are switched.

Next, an example of the detailed configuration of the output control section 200 will be described with reference to FIG. In the figure, reference numeral 210 denotes a valid data discriminating circuit, which is the same as the valid data discriminating circuit 150 in the motion detecting unit 100 described above. 230 is a dual port frame memory for storing digital image data s20, 220 is a write address generation circuit for generating a write address of the frame memory 230, 250
Is a read address generation circuit that generates a read address of the frame memory 230, 240 is a flag register that stores the image change signal s100 for each horizontal display line,
Reference numeral 260 denotes the FLCD display unit 4
00 is a data formatter for converting into a displayable format.

The valid data discriminating circuit 210, like the valid data discriminating circuit 150 described above, has a vertical synchronization signal s4.
0, the horizontal synchronization signal s30, and the dot clock s50, and output the effective display area signal s210 to the write address generation circuit 220 and the flag register 240.

The write address generation circuit 220 generates a write address s220 for writing the image data s20 into the frame memory 230, and generates the write address s22.
0, the image data s20 is stored in the frame memory 230.
Written to

The flag register 240 stores the image change signal s
100 is received and stored as a flag of motion information for each horizontal display line.

The read address generation circuit 250 receives the flag information s240 from the flag register 240 based on the request signal s200 from the transmitter 300, identifies the line in which the image has moved, and
The read address s250 is output to 0, and the display line number s260 is output to the data formatter 260.

The data formatter 260 receives the rewrite display line number s26 from the read address generation circuit 250.
0 from the frame memory 230 to the rewritten image data s
230, and replaces the rewritten image data s230 with a partially rewritten image data format as shown in FIG. Then, the partially rewritten image data s20
0 is output to the transmitter 300.

The transmitter 300 receives the partially rewritten image data s200 and transfers the partially rewritten image data s200 to the receiver 500 of the FLCD display unit 400 by performing wireless data communication. When the data transfer is completed, the request signal s
200 is output to the output control unit 200.

On the other hand, the FLCD display unit 40
In the case of 0, the signal transmitted from the transmitter 300 is received by the receiver 500, and the partially rewritten image data s300 is output to the display control unit 600.

The display control unit 600 drives only the FLCD driver corresponding to the display line indicated by the input partial rewrite image data s300, and rewrites the image data of that line. In other words, FLC has a so-called memory property, in which the ON / OFF state of the liquid crystal is maintained even when the electric field required for switching is removed. Therefore, by utilizing this property, only the changed line can be rewritten. Thus, an image of the entire frame can be displayed.

As described above, according to the display control apparatus of the present embodiment, even if wireless communication with a low transfer rate is used for computer image transmission, the motion detection unit 100
Since only the image data of the display line where the image change is detected is transmitted to the FLCD display unit 400,
For example, a computer image with good responsiveness to a partial change on the screen such as a mouse movement can be obtained.

<Second Embodiment> Hereinafter, a second embodiment according to the present invention will be described.
An embodiment will be described.

In the second embodiment, a plurality of FLCDs
An example in which wireless data communication is efficiently performed with the display unit will be described.

The basic block configuration of the display control device according to the second embodiment is substantially the same as that shown in FIG. 1 shown in the first embodiment, and a description thereof will be omitted. In the second embodiment, three FLCD display units are used. It is characterized by having a table.

Hereinafter, the description will be focused on the differences from the first embodiment.

FIG. 6 is a block diagram showing a detailed configuration example of the motion detecting section 100 in the second embodiment. In the figure, 125 and 135 are changeover switches, 140 and 1
Reference numerals 41 and 142 denote frame buffers for storing the compressed image data s110 for two frames, and each frame buffer corresponds to three FLCD display units. The other configuration of the motion detection unit 100 is the same as that of the first embodiment shown in FIG.

The input digital image data s20 is
The image is compressed by the image conversion circuit 110 and sent to one of the frame buffers 140, 141 and 142 selected by the switch 125. Then, for example, when the frame buffer 140 is selected by the switch 125 and the switch 135, the transmitted latest compressed image data s110 is stored in the Buf. 1 corresponding to the display content of the FLCD display unit to be transmitted. The second compressed image data s120 is sent to the comparison circuit 160.

The switch 125 and the switch 135 select one of the frame buffers 140 to 142 corresponding to the FLCD display unit to be transmitted based on the control signal s70, and in the selected frame buffer, Buf. 1 and Buf. 2 is exclusively selected.
For example, when the switch 125
uf. 1 is selected, the switch 135 sets the Buf. Select 2. In the system controller 80, the compressed image data corresponding to the display screen is stored in the Buf. 1 or Bu
f. 2 is controlled, and the switch 125 and the switch 135 are controlled so that the latest compressed image data s110 is input to a buffer in which the display data is not stored. The switches 125 and 13
Switching of 5 is performed in synchronization with the vertical synchronization signal s40.

In the motion detecting section 100, the processing operation of the other components is the same as that of the first embodiment described above.
Description is omitted.

Next, FIG. 7 shows a detailed configuration example of the output control section 200 in the second embodiment.
Since the configuration is almost the same as that described above, detailed description is omitted.

In the second embodiment, the data formatter 260 selects the FLCD selected by the system control unit 80.
It receives the display unit signal s80 and adds an ID number corresponding to the selected FLCD display unit to the partially rewritten image data as shown in FIG. Then, it outputs the partially rewritten image data s200 to the transmitter 300. The processing operation in other configurations is the same as in the first embodiment.

Next, FIG. 9 shows the FLC according to the second embodiment.
4 shows a configuration example of a D display unit 700. In the figure, reference numeral 800 denotes an ID identification circuit, which identifies whether or not the transmitted partial rewrite image data s700 has been transmitted to the display unit by a unique ID number. That is, the partially rewritten image data s7
The ID number of 00 is the ID of this display unit
Is output to the output control unit 600 only when the line number matches the line number to be rewritten. Processing operations in other configurations are the same as in the first embodiment.

In the second embodiment, three FLCs are used.
Although the example in which the wireless data communication to the D display unit is performed has been described, the number is not limited to three, and the FLCD display units to be transmitted are each assigned a unique ID number, and each of the FLCD display units is provided with a motion detection unit 100. Wireless communication is possible with any number of FLCD display units as long as the correspondence with the frame buffer in the above can be achieved.

As described above, according to the second embodiment, even when wirelessly transferring computer image data to a plurality of FLCD display units, it is possible to efficiently transfer the minimum necessary data wirelessly, and to perform image change. Responsiveness to the system is dramatically improved.

Third Embodiment Hereinafter, a third embodiment according to the present invention will be described.
An embodiment will be described.

In the third embodiment, an example will be described in which wireless data communication with a display unit having another device such as a TFT liquid crystal display or a CRT is efficiently performed.

The basic block configuration of the display control device according to the third embodiment is substantially the same as that of the first embodiment shown in FIG. 1, and thus the description thereof is omitted. However, the display unit is not an FLCD.

FIG. 10 shows a configuration example of a display unit 900 according to the third embodiment. In FIG.
Reference numeral 00 denotes a frame memory, and other configurations are the same as those of the FLCD display 400 of the first embodiment.
Description is omitted.

In general, in a display other than the FLCD, since image data cannot be held in the device, it is necessary to constantly scan the entire screen. Therefore, in the third embodiment, the display control unit 600 rewrites the content of the frame memory 1000 corresponding to the transmitted partial rewrite image data s300, but the display control unit 600 further updates the content in accordance with the refresh operation of the display device. The display screen is maintained by transferring the image data from the frame memory 1000 to the display driver.

The other configurations and the processing operations in the third embodiment are the same as those in the first embodiment.

As described above, according to the third embodiment, efficient wireless image data communication is possible even for a display unit having no memory.

<Other Embodiments> The present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a display, a printer, etc.), and a device including one device (for example, For example,
Word processor).

Another object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and a computer (or CPU) of the system or apparatus.
And MPU) read and execute the program code stored in the storage medium.

In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instruction of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0058]

As described above, according to the present invention, only a display line having an image change is transmitted to a display unit having a memory function. The image is updated at high speed.

Accordingly, it is possible to obtain a sufficient responsiveness to a partial change on the display screen such as a mouse movement.

Also, in order to enable wireless communication,
It is free from the confusingness of connecting the cable of the display unit, and the degree of freedom of arrangement of the display unit is improved. In particular, when data is transferred to a plurality of display units, the effect is remarkable.

Furthermore, since the amount of transmission data can be reduced particularly on a computer screen with little movement, efficient use of the communication band and power saving can be achieved.

[0062]

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a display control device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a detailed configuration of a motion detection unit according to the embodiment.

FIG. 3 is a block diagram illustrating a detailed configuration of an output control unit according to the embodiment.

FIG. 4 is a diagram showing an example of a partially rewritten data format according to the embodiment.

FIG. 5 is a flowchart illustrating processing of a system control unit according to the present embodiment.

FIG. 6 is a block diagram illustrating a detailed configuration of a motion detection unit according to a second embodiment of the present invention.

FIG. 7 is a block diagram illustrating a detailed configuration of an output control unit according to a second embodiment.

FIG. 8 is a diagram illustrating an example of a partially rewritten data format according to the second embodiment.

FIG. 9 is a block diagram illustrating a configuration of an FLCD display unit according to a second embodiment.

FIG. 10 is an FLCD according to a third embodiment of the present invention.
FIG. 3 is a block diagram illustrating a configuration of a display unit.

[Explanation of symbols]

 Reference Signs List 70 clock generator 80 system controller 100 motion detector 200 output controller 300 transmitter 400 FLCD display unit

Claims (16)

[Claims] An image input unit for inputting an image signal on a frame basis; a motion detection unit for detecting a change in an image for each frame; and an output of changed image information according to a detection result by the motion detection unit. Output control means for transmitting the image information output by the output control means, and display means for displaying an image based on the data transmitted by the communication means. Display system. 2. The image display system according to claim 1, wherein said display means has a memory function of displaying an image. 3. The image display system according to claim 2, wherein said display means displays an image by scanning a plurality of lines and keeps holding the image display by one scanning. 4. The image display system according to claim 3, wherein said display means is a ferroelectric liquid crystal display. 5. An image display according to claim 1, wherein said display means updates an image portion corresponding to data transmitted by said communication means and displays an image. system. 6. The image display system according to claim 1, wherein said communication unit transmits image information by wireless communication. 7. The image display system according to claim 1, wherein said output control means outputs changed image data and its position information in accordance with a detection result by said motion detection means. 8. The image display system according to claim 6, wherein said position information is a display line number. 9. The image processing apparatus according to claim 1, further comprising a holding unit that holds the image signal input by the image input unit on a frame basis, wherein the motion detecting unit detects a change in an image for each frame held by the holding unit. The image display system according to claim 1, wherein the image is detected. 10. The display means has a display memory, updates only an image portion corresponding to data transmitted by the communication means on the display memory, and displays a display screen with an image held in the display memory. 2. The image processing apparatus according to claim 1, wherein the apparatus is constantly refreshed. 11. An image display system having a plurality of display means for performing image display, comprising: an image input means for inputting an image signal on a frame basis; a motion detecting means for detecting a change in an image for each frame; An output control unit that outputs changed image information according to a detection result by the motion detection unit, and further outputs an identifier that specifies a display unit to be displayed among the plurality of display units; and the output control unit. Communication means for transmitting the image information output by the above and the identifier of the display means to the plurality of display means, wherein the plurality of display means display an image based on the data transmitted by the communication means. An image display system characterized by performing. 12. The display device according to claim 11, wherein each of the plurality of display units updates an image display based on the image information if an identifier transmitted by the communication unit identifies itself. Image display system as described. 13. The apparatus according to claim 1, wherein each of said plurality of display means is a ferroelectric liquid crystal display.
1. The image display system according to 1. 14. The image display device according to claim 11, wherein each of the plurality of display units updates an image portion corresponding to data transmitted by the communication unit and performs image display. Image display system. 15. The image display system according to claim 11, wherein said communication means transmits image information by wireless communication. 16. An image inputting step of inputting an image signal on a frame basis, a motion detecting step of detecting a change in an image for each frame, and outputting changed image information according to a detection result in the motion detecting step. An output control step of: transmitting an image information output in the output control step; and a display step of displaying an image based on the data transmitted by the communication step. Display method.