JPH0683295A - Multimedia display system - Google Patents

Abstract

PURPOSE:To provide such a liquid crystal display system that when a display of a personal computer and displays of animation and a still picture of a natural picture and the like are mixed on a multi-gradation liquid crystal display for the personal computer, color of a picture of a natural picture display section is not made unnatural display caused by restriction of the number of display gradation. CONSTITUTION:In order to display simultaneously a personal computer display and a TV display and the like on a liquid crystal display 180, this system is provided with a multi-gradation control section 160, and a superposition control section 140 which switches validity or invalidity of multi-gradation control by a unit of display picture element. And the number of gradation displayed by the liquid crystal display is expanded and multi-colors is achieved by multi- gradation control, the natural picture display section on the liquid crystal display is made multi-colors and a natural display is obtained by switching validity or invalidity of multi-gradation control with a signal indicating that a display region is in a personal computer display state or a video display state of a TV and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a multi-gradation display with a natural image which requires a large number of gradation display in addition to the display of text, graphics, etc. from an information processing system such as a personal computer. , A multimedia display system capable of displaying moving images or still images at the same time.

[0002]

2. Description of the Related Art A conventional liquid crystal multi-gradation display system is a display for a personal computer (hereinafter abbreviated as a personal computer) with a resolution of 640 × 480, and each pixel has an R, G, B 8th floor. With a liquid crystal cell
There is a display system using a liquid crystal display that displays 512 colors. Also, for displaying natural images,
A liquid crystal TV using an analog liquid crystal display is known.

A known example of a liquid crystal display for a personal computer and a liquid crystal display for a TV is "Asahi Shimbun (Evening Edition) January 29, 1992, 7th page, color liquid crystal display panel". On the other hand, as a technique for simultaneously displaying a personal computer and a TV, as described in Japanese Patent Laid-Open No. 3-59696, a video signal for TV is converted into a timing for personal computer display by using a scan converter or the like, and then displayed on the personal computer. There is a device for displaying a screen of a TV or the like on a CRT display by superimposing the screen.

[0004]

By the way, a multi-gradation (multi-color) liquid crystal display developed for a personal computer has a CR
In some cases, the display contents when a personal computer display and a TV or the like are simultaneously displayed, as realized by a system using a T display, may be displayed. In this case, according to the above-mentioned conventional technique, since the number of displays of the liquid crystal display is 512 colors, the display color (gradation) used in the text and graphics display is 16 colors, 64 colors and the liquid crystal display in the personal computer display part. Within the number of display colors (the number of gradations) of, it is possible to display without problems. However, the number of display colors (the number of gradations) is limited in the display part of a TV or the like, so that the color of the pixel is crushed, or the boundary like a contour line appears in the smooth part, There is a problem that a natural display cannot be performed.

On the other hand, when a personal computer display is performed on an analog liquid crystal display used in a liquid crystal TV or the like, lines and characters are clear because the RGB arrangement of the liquid crystal cells is different from that for a personal computer and is not a stripe pattern. There are none. In addition, if the number of pixels is less than the required resolution, a part of the display content must be enlarged and displayed.
There are problems such as not being able to read the characters.

An object of the present invention is to mix a personal computer display and a moving image / still image display such as a natural image on a multi-gradation display for a personal computer, in which case the color of the image in the natural image display portion is displayed on the display floor. An object of the present invention is to provide a display system capable of displaying without causing an unnatural display due to the limitation of the number of keys and a multimedia reproducing system using this liquid crystal display system.

[0007]

In the present invention, in order to display a personal computer and a TV on the liquid crystal display at the same time, multi-grayscale control, whether the display area is a personal computer display or a TV or other video display. Means for inputting a signal indicating
It is provided with a means for switching between valid and invalid multi-gradation control in display pixel units.

That is, according to one aspect of the present invention, a multi-gradation display is required in a display system having a multi-gradation display and a multi-gradation control unit for performing multi-gradation display on this display. First display data generating means for generating and outputting display data, second display data generating means for generating and outputting display data that does not require multi-gradation display, and first and second display data generating means. The output data from the means is switched from one to the other and is input to the multi-gradation control unit. The overlay control unit detects the specific area on the screen specified in advance. Then, according to the instruction, means for generating a key signal for switching the output of the first display data generating means and the output of the second display data generating means to the other currently displayed. And a switching means for switching the display of the output of the first display data generating means and the output of the second display data generating means in response to the key signal. In response to this, a display system is provided, which is provided with means for switching whether or not to perform multi-gradation display.

The means for generating the key signal may be one for generating the key signal for each display pixel.

Further, the multi-gradation control section can switch between valid and invalid of the multi-gradation control in display pixel units according to a key signal.

Further, the display portion indicated by the key signal is
It is a moving image or a still image of natural color, and the other display portion can be display data composed of a display color less than the display color of the multi-tone liquid crystal display.

[0012]

In the multi-gradation control, the number of gradations (the number of colors) is further expanded to increase the number of gradations (the number of colors) displayed on the liquid crystal display for personal computer display. The area for performing multi-gradation display on the display is determined by means of inputting a signal indicating whether the display area is a personal computer display or a TV image display, and multi-gradation control is switched between valid and invalid in display pixel units. The multi-gradation control is performed only in the area determined by the means.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of the multimedia liquid crystal display system of the present invention. Further, FIG. 11 shows a configuration of an embodiment of a multimedia reproducing system to which the multimedia liquid crystal display system is applied.

The multimedia playback system shown in FIG. 11 is composed of a computer system such as a personal computer.
That is, a central processing unit (CPU) 1000 that processes various data such as display data, and a main memory 1001 that stores programs and data of the CPU 1000.
A device 1003 and an input interface 1002 for inputting various instructions and data to the system, an auxiliary storage device 130a for storing programs and data, and a bus 10 for connecting them.
Has 0 and.

Further, this multimedia reproducing system comprises a personal computer display system 110 which is a display means usually provided as a personal computer as a part constituting the multimedia liquid crystal display system, and a moving picture / still picture for reproducing a natural picture or the like. The image reproduction unit 120, an overlay control unit 140 for overlaying the images of both images, and a multi-display display 150 are included.

The CPU 1000 has a function of designating an area in which multi-gradation display will be described later. That is, the CPU 1000 has a function of selecting an area to be displayed in multiple gradations in the displayed screen and filling the plain area with a predetermined specific color. This area can be designated by various methods such as designation by an application program and designation by the user via the input device 1003.

In this embodiment, the auxiliary storage device 1 is used.
30a is a compressed moving image / still image storage medium for compressing and storing a moving image / still image displayed in the multimedia liquid crystal display system, as a component of the multimedia liquid crystal display system. 1 (indicated by reference numeral 130). The compressed moving image / still image storage medium 130 is read out or read out.
It is a writable storage medium, and is composed of, for example, a magnetic disk device, a magneto-optical disk device, a CD-ROM device, a semiconductor memory and the like. The compressed moving image / still image storage medium 130 stores data obtained by compressing moving image and still image data using a specific data compression algorithm.

Further, in the system of this embodiment, CRT displays 115 and 145 can be connected to the personal computer display system 110 and the overlay control section 140, respectively.

Next, the structure of the multimedia liquid crystal display system will be described with reference to FIG.

As described above, the multimedia liquid crystal display system of this embodiment includes the personal computer display system 110, the moving image / still image reproducing unit 120, the superposition control unit 140,
It has a multi-display display 150 and a compressed moving image / still image storage medium 130 (130a). That is, in this embodiment, the display control function can be roughly classified into four control units.

The first control unit is a personal computer display system 110, and is a unit for performing graphic display, text display, etc. as a display output of an application program operating on the personal computer. The personal computer display system 110 performs display control and draws image data to be displayed, a display control / drawing unit 111, a video RAM (VRAM) 112 that stores the image data, and the drawn image data in an analog form. A / D converter (R) with pallet that converts to data and sends to externally connected CRT display 115
AMDAC) 114.

The display control / rendering unit 111 has a VRAM 11
The display data is read from 2 and a display signal that matches the display timing for the CRT is output. RAMDAC11
Reference numeral 4 is provided with a color designating register capable of designating a display color used in a personal computer display system.

The second control unit is the moving image / still image reproducing unit 12
The compressed data of the moving image or the still image stored in the compressed moving image / still image storage medium 130 is expanded and displayed, and the video signal input from the video signal input 121 is displayed on the CRT for a personal computer. Convert and output to display timing,
The compressed moving image / still image storage medium 1 is used for displaying or compressing a video signal input from the video signal input 121.
This is a part for performing control such as writing to 30. The moving image / still image reproducing unit 120 includes a moving image / still image data compression / decompression control unit 122, a display memory 125 for storing compressed / decompressed moving image / still image data, and moving image / still image data from the display memory 125. Reading display Reading control unit 1
26 and.

The display memory 125 is a VRAM (video RAM) having a capacity of at least one frame of the display screen. The moving image / still image data compression / decompression control unit 122
The data read from the compressed moving image / still image storage medium 130 is subjected to arithmetic processing using a data decompression algorithm and decompressed, and one frame of still image data is displayed in the display memory 125.
Or the moving picture display data for a plurality of frames at the reproduction frame rate of the moving picture are sequentially written in 1 second via the data bus 124. Display reading control 12
Reference numeral 6 reads the display data from the display memory 125, controls the size of the display screen, the display position, etc., and generates a display data signal that matches the display timing of the CRT for the personal computer.

The third control unit is the superposition control unit 140.
And the display output from the video / still image playback unit 120,
The display output from the personal computer display system 110 is combined by switching the display pixel unit, and output is performed on one display. The overlay control unit 140
An A / D converter 127 that converts the display data of the moving image / still image output from the display reading control unit 126 into analog data, and a palette that converts the image data from the display control / drawing unit 111 into analog data. A / D converter (RAMDAC) 143, a key signal generation unit 141 that switches the polarity of the key signal 142 only when an input color is a specific color, an output of the A / D converter 127, and an output of the RAMDAC 143. And a switching means 144 for switching and outputting according to the polarity of the key signal 142.

The RAMDAC 143 has a color designating register capable of designating the same number of display colors as the RAMDAC 114 used in the personal computer display system, and the same value as the color data written in the color designating register of the RAMDAC 114 is written. Be done. Therefore, RA
The display output output from the MDAC 143 is the same as that of FIG. 7 in terms of the screen configuration display color. Key signal generator 1
Reference numeral 41 is to input and decode color data of a display signal output from the display control / drawing unit 111, and switch the polarity of the key signal 142 only when the input color is a specific color. The A / D converter 127 is
It may be considered as a component of the moving image / still image reproducing unit 120.

The fourth control unit is a multi-display display 150, which outputs a CRT display signal of analog RGB to 51.
This is a part for performing data conversion for displaying on a two-color TFT liquid crystal display and displaying on a 512-color TFT liquid crystal display, and further performing multi-gradation control to perform 32768-color display on the 512-color TFT liquid crystal display.
The multi-display display 150 performs polarity switching, multi-gradation mode switching, and the like, and a multi-gradation control unit 160 that performs control for multi-gradation display of input display data. Switching circuit (hereinafter, simply referred to as polarity / mode switching circuit) 17
Liquid crystal display 18 that can display 0 and 512 colors
Has 0 and.

The multi-gradation control section 160 separates the analog RGB sync signal 146 into a vertical sync signal and a horizontal sync signal for scanning a CRT display, and further provides a dot clock that defines the timing of displaying each pixel data of RGB. The clock reproduction 161 to generate, the A / D converter 163 having at least 5 bits or more of digital output for each RGB input, and converting each pixel of the display data into digital data, and the same number of bits as the A / D converter 163 With three data widths for R, G, and B that have at least one line of data on the display screen, and when the input display data is the interlaced display timing, the same data is output by two lines, and non-interlaced data is output. A line memory 164 for converting to race display data and RGB line memories 16 Has a number of inputs of the same bits as the number of bits of output data, the gradation pattern ROM16 for RGB and each 3-bit output, the horizontal driver 512-color display liquid crystal display 180, and outputs the display data for vertical driver
5 and a control circuit 162 that controls these operations.

The control circuit 162 outputs the sync signal and the dot clock from the clock recovery 161 to the clock control signal 16
9 to generate timings for converting, writing, and reading data in dot (pixel) units, and by the control signal 171 the A / D converter 163 and the line memory 1
64, gradation ROM pattern 165 is controlled. further,
The control circuit 162 generates display timing data for the liquid crystal driver and outputs a display control signal 168. Further, the gradation pattern ROM 165 includes a line memory 164.
From, RGB display data of 5 bits or more (32768 colors or more) is input. The gradation pattern ROM 165 performs an operation of thinning out this to 32768 colors and an operation of converting 32768 colors into data for displaying each of RGB 3 bits by using a dither pattern.

If the input data is only non-interlaced, the line memory 164 and the line memory 1700 described later can be omitted.

The polarity / mode switching circuit 170 is a part for performing setting of valid / invalid of the key signal 142, gradation control by the key signal 142, polarity reversal of the key signal 142, gradation control by manual operation, and the like. 16
6 outputs the key signal 142 obtained by delaying the signal delay due to the multi-gradation control 160 by an amount, or outputs the key signal 1
42 is a portion for inverting and outputting 42, or for outputting a fixed level signal to enable or disable gradation control over the entire screen. The configuration of an embodiment of the polarity / mode switching circuit 170 is shown in FIG.

In FIG. 2, the key signal 142 is the resistance 1
71, and the other end of the resistor 171 is connected to the resistor 172 and the first input of the exclusive OR circuit (EOR) 173. The other end of the resistor 172 has a resistor 174 and an EOR 173.
Of the switch (Sw1) 175 and the switch (Sw2) 176. Resistance 1
The other end of 74 is connected to the power supply 177. Switch (S
The other end of w1) 175 is connected to the ground 178.
The output of the EOR 173 is connected to the second input of the switch (Sw2) 176, and the output of the switch (Sw2) 176 is connected to the resistor 179.

The other end of the resistor 179 is connected to the line memory 170.
Input to 0. The output of the line memory 1700 is connected to a jumper (JP1) 1701. Jumper (JP
1) The other end of 1701 is the switching output 166 and is connected to the resistors 1702 and 1703. Resistance 170
The other end of 2 is connected to the power supply 177, and the other end of the resistor 1703 is connected to the switch (Sw3) 1704. The other end of the switch (SW3) 1704 is connected to the ground 178.

Here, the resistance 171 is 47 ohms, and the resistance 1
72 has a resistance value of 1 M (mega) ohm, resistor 174 has a resistance value of 4.7 K (kilo) ohms, resistor 179 has a resistance value of 47 ohms, resistor 1702 has a resistance value of 10 K (kilo) ohms, and resistor 1703 has a resistance value of 100 ohms. The switch (Sw1) 175 and the switch (SW3) 1704 are two terminals on / off.
A switch, a switch (Sw2) 176 is a 2-input 1-output changeover switch, and a line memory 1700 is a signal delay adjustment buffer that operates at the same input / output timing as the line memory 164.

The liquid crystal display 180 is 640 × 48.
TFT liquid crystal panel 181 with 0 color pixels, 51
Horizontal driver 182 and vertical driver 1 for two-color display
And 83.

Next, the connection relation of each part constituting the embodiment shown in FIG. 1 will be described. The personal computer bus 100 includes a compressed moving image / still image storage medium 130, a VRAM 112 of a personal computer display system 110, and a display control / drawing unit 111.
And are connected.

The moving picture / still picture data compression / expansion control section 122 of the moving picture / still picture reproduction section 120 is connected to the personal computer bus 100 via the data bus 123, and is connected to the moving picture / still picture data compression / expansion control section 122. Is connected to the video signal input 121. The moving image / still image data compression / decompression control unit 122 and the display memory 125 are connected to the data bus 124.
Connected by. The output of the display memory 125 is input to the display read control 126. The output of the display read control 126 is the D / A converter 1 of the superposition control unit 140.
Connected to 27 inputs.

VRAM 112 and display control / drawing unit 111
And are connected by a data bus 113. The synchronous clock 116 output from the display control / drawing unit 111 is input to the display reading control 126, and the display control / drawing unit 111
Is output from the RAMDAC 14 of the overlay control unit 140.
3, the key signal generator 141, and the personal computer display system 11
0 to the RAMDAC 114. RAMDAC1
The output of 14 is input to the CRT 115. RAMDA
Although C114 and CRT115 are used for explaining the operation of the present invention, they can be omitted from the constituent elements in the implementation of the present invention. At this time, RAM
Instead of using DAC143, RAMDAC114
May be used.

The output of the D / A converter 127 of the superposition control section 140 is connected to one input of the switching means 144. The output of the RAMDAC 143 is the switching means 1
44 to the other input. The key signal 142 output from the key signal generation unit 141 is input to the switching control input of the switching unit 144 and the polarity / mode switching circuit 170 of the multi-display display 150. The analog RGB and synchronization signal 146 output from the switching unit 144 is input to the CRT 145, the clock reproduction unit 161 and the A / D converter 163 of the multi-gradation control unit 160. The CRT 145 is used to explain the display operation of the present invention, but it can be omitted in the implementation of the present invention.

In the multi-gradation control section 160, the clock reproduction section 161 and the control circuit 162 are connected by a clock / control signal 169. The output of the A / D converter 163 is connected to the line memory 164. Line memory 1
The output of 64 is input to the gradation pattern ROM 165.
The control signal 171 output from the control circuit 162 is A /
The data is input to the D converter 163, the line memory 164, and the gradation pattern ROM 165. The display control signal 168 output from the control circuit 162 and the display data 167 output from the gradation pattern ROM 165 are input to the liquid crystal display 180 of the multi-display display 150.
The switching output 166 output from the polarity / mode switching circuit 170 is input to the gradation pattern ROM 165.

Next, the operation of this embodiment configured as described above will be described with reference to the drawings.

First, the operation of the display shown in FIG. 8 on the CRT 145 by the moving image / still image reproducing section 120 will be described. In FIG. 8, a moving image / still screen 604 in which a moving image or a still image is reduced is displayed in a part of the display screen 601 of the CRT 145.
Shows an example in which is displayed. This display is performed as follows.

The moving picture / still picture reproduction section 120 compresses the moving picture / still picture data from the compressed moving picture / still picture storage medium 130 to the moving picture / still picture data compression / expansion control section 122 via the personal computer bus 100 and the data bus 123. Read still image data. Video / still image data compression / decompression controller 1
Reference numeral 22 expands the data read from the compressed moving image / still image storage medium 130 by arithmetic processing using a data expansion algorithm. Then, the moving image / still image data compression / decompression control unit 122 writes one frame of still image data into the display memory 125 via the data bus 124, or a plurality of frames depending on the playback frame rate of the moving image per second. Minute video display data is sequentially written.

The display read control 126 controls the display memory 1
The display data is read from 25, the size and the display position of the display screen are controlled, and the display data signal is generated in accordance with the display timing of the CRT for the personal computer. D / A
The converter 127 converts the display data signal output from the display reading control 126 from digital to analog for an analog RGB CRT display and outputs it. The display output from the D / A converter 127 is displayed on the CRT1.
When it is displayed by connecting to 45, the display screen is as shown in FIG.
become that way.

Next, using the personal computer display system 110, as shown in FIG.
The operation of displaying the display contents shown in (1) on the CRT 115 will be described.

In FIG. 1, the display output contents of the application program operating on the personal computer are displayed by the CPU 1000 (see FIG. 11) connected to the personal computer bus 100.
Written to VRAM 112 or display control /
VR via the data bus 113 via the drawing unit 111
Written to AM 112. Furthermore, CPU1000
According to an instruction from the application program, fills the area of the display screen generated by the moving image / still image reproducing unit 120 in which the moving image / still image screen 604 is to be displayed with a specific color. The display control / drawing unit 111 is a VRAM.
The display data is read from 112 and is output as a display signal that matches the display timing for the CRT. The display signal output from the display control / drawing unit 111 is RAMDA.
The digital signal is converted to an analog signal by C114 and output to CRT115. At this time, CRT115
The configuration content of the screen displayed in is as shown in FIG. The filled area may be configured to be executed by the CPU 1000 in response to an instruction from an input device of the system shown in FIG.

In FIG. 7, on the display screen 701, a graphic 602 is displayed in the full size of the drawing as display output contents of the application program operating on the personal computer, and a display 603 including a table and a text display is displayed therein. Is displayed. Furthermore, the moving image / still image screen 6 on the display screen generated by the moving image / still image reproducing unit 120.
A portion 704 in which the same area as that in which 04 is displayed is filled with the specific color is displayed.

Next, the overlay control section 140 causes C
The operation of performing the display shown in FIG. 6 on the RT 145 will be described.

The RAMDAC1 has a RAMDAC1
The same value as the color data written in the 14 color designation register is written. Therefore, the display output output from the RAMDAC 143 is the same as that shown in FIG. The key signal generation unit 141
The color data of the display signal output from the display control / drawing unit 111 is input and decoded, and the polarity of the key signal 142 is switched only when the input color is a specific color. The input color for switching the polarity of the key signal 142 is set to the color of the area 704 filled with a certain specific color shown in FIG. At this time, if the display data input from the display control / drawing unit 111 to the key signal generation unit 141 is a color that fills the area 704 shown in FIG. 7, the key signal generation unit 141 outputs the key signal 142 Switch the polarity.
As a result, the switching means 144 switches its input and selects the output of the D / A converter 127.

The synchronization of the display operations of the moving image / still image reproducing unit 120 and the personal computer display system 110 is performed by the synchronization clock 1
16. Therefore, as shown in FIG. 6, the display screen when the analog RGB and the synchronizing signal 146 are input to the CRT 145 has the moving image / still image screen 604 shown in FIG. 8 embedded in the region 704 shown in FIG. It becomes a display screen.

Next, the display operation by the multi-display 150 will be described.

The relationship between the display signals from the analog RGB and sync signals 146 and the key signal 142 is shown in FIG.

When the display data input to the multi-display 150 is the moving image / still image screen 604 of FIG.
The level of the key signal 142 is inverted. Multi-gradation control unit 16
0 controls the display output by expanding the display color from 512 colors to 32768 when the multi-gradation control is valid by the switching output 166 input from the polarity / mode switching circuit 170. In the polarity / mode switching circuit 170,
Settings of valid / invalid of the key signal 142, gradation control by the key signal 142, polarity inversion of the key signal 142, and gradation control by manual operation are performed. For example, as the switching signal 166, the key signal 142 obtained by delaying the signal delay by the multi-gradation control unit 160 is output, the key signal 142 is inverted and output, or the fixed level signal is output. Control for enabling or disabling the key control is performed on the entire screen.

The operation of the polarity / mode switching circuit 170 of FIG. 2 will be described with reference to FIG.

When the key signal 142 is not input, the jumper (JP1) 1701 is opened and the output level of the switching output 166 is set by the switch (Sw3) 1704. When the switch (Sw3) 1704 is on, the switching output 166 is fixed at a low level, and when the switch (Sw3) 1704 is off, the switching output 166 is fixed at a high level, and the multi-gradation control unit 160 is provided.
The control by is valid or invalid on all display screens.

When the key signal 142 is input and the gradation of the moving image / still image screen is switched, a jumper (JP
1) Short 1701 and switch (Sw3) 17
With 04 as off, the input of the switch (Sw2) 176 selects the EOR 173 side. Switch (Sw1) 17
Reference numeral 5 switches the input polarity of the key signal 142. When the switch (Sw1) 175 is on, the key signal 142 is directly output from the EOR 173. When the switch (Sw1) 175 is off, the key signal 142
Has its polarity inverted and becomes the output of EOR173. EO
The output of R173 becomes the switching output 166 via the line memory 1700. At this time, the multi-gradation control unit 160
The switching output 166 input to the signal is adjusted by the line memory 1700 for the difference between the key signal 142 in FIG. 9 or its inverted signal and the delay amount of the display data in the control circuit of the multi-gradation control section 160. I'm typing.

When the key signal 142 is being input, the jumper (JP1) 170 is used to enable or disable the gradation control by the multi-gradation control section 160 for the entire display screen.
1 is shorted and switch (Sw3) 1704 is off
As f, the input of the switch (Sw2) 176 is set to the switch (Sw1) 175 side. Switching output 16 at this time
6 is a switch (Sw1) 17 regardless of the key signal 142
By 5, the output level is fixed.

Next, the operation of the multi-gradation control section 160 will be described.

The clock reproducing unit 161 is an analog RGB
A vertical synchronizing signal and a horizontal synchronizing signal for CRT display scanning are separated from the synchronizing signal 146, and a dot clock that defines the timing for displaying each pixel data of RGB is generated. The A / D converter 163 converts each pixel of display data into digital data. Line memory 1
When the input display data is at the timing of interlaced display, 64 outputs the same data for two lines to convert it to data for non-interlaced display.

The control circuit 162 includes a clock recovery section 161.
Clock control signal 1 from sync signal and dot clock from
The data is input via 69, and the conversion, writing, and reading timing of dot (pixel) data is generated. Also,
The control circuit 162 controls the A / D converter 163, the line memory 164, and the gradation ROM pattern 165 by the control signal 171. Further, the control circuit 162 generates display timing data for the liquid crystal driver and outputs the display control signal 168.

The gradation pattern ROM 165 outputs 3 bits for each of RGB and outputs display data for a horizontal driver and a vertical driver of the liquid crystal display 180 displaying 512 colors. The gradation pattern ROM 165 has a line memory 164.
From RGB, display data of 5 bits or more for each RGB (32768 colors or more) is input. The operation of thinning this out to 32768 colors and converting it to data for displaying 32768 colors with 3 bits for each RGB using a dither pattern. Do an action. This will be described with reference to FIG.

In order to display 32768 colors, RGB
32 gradations are required for each. However, the liquid crystal display 180 used in this embodiment has drivers 181 and 182 for displaying 512 colors, and the data has 8 gradations for each of RGB. In FIG. 5, the display pattern on the liquid crystal display 180 performs multi-gradation display with a 2 × 2 dither pattern. When the gradation level is 32 gradations, 501 indicates a dither pattern at the gradation level 12, 502 indicates a dither pattern at the gradation level 13, 503
Indicates a dither pattern at a gradation level of 14,
Reference numeral 4 indicates a dither pattern when the gradation level is 15.
Reference numeral 05 denotes a dither pattern when the gradation level is 16.

The gradation data input to the liquid crystal display 180 is 8 gradations (3 bits) for each of RGB, 0,
1, 2, 3, 4, 5, 6, and 7. In order to extend this to 32 gradations, this value is multiplied by 4 and expressed. FIG. 5 shows that between the gradation levels 12 and 16
2 shows an example in which the gradations 13, 14, and 15 are generated using a 2 × 2 dither pattern using the gradation 16 and the gradation 16. In the dither pattern 501 at the gradation level 12, all four dots are at the level 12. In the dither pattern 502 at the gradation level 13, three of the four dots are 12
And one is 16, and on average level 13
become. Dither pattern 503 when gradation level is 14
2 out of 4 dots is 12 and 2 out of 16
Therefore, the average level becomes 14. The dither pattern 504 when the gradation level is 15 is one of four dots.
One is twelve, three are sixteen, and on average they are at level fifteen. In the dither pattern 505 at the gradation level 16, all four dots are at the level 16.

The gradation pattern ROM 165 stores the data from the line memory 164 and the control signal 1 from the control circuit 162.
71 and the switching output 166 are used to generate a 2 × 2 dither pattern. At this time, the switching output 166 allows the dither pattern to be 2 × when the multi-gradation control is invalid.
The gradations of the 2 dots are all the same, which is 8 gradations. Therefore, when multi-gradation control by the key signal 142 is enabled by the polarity / mode switching circuit 170, multi-gradation display on the liquid crystal display 180 is as shown in FIG.

In FIG. 4, the portion with multi-gradation control indicated by the key signal 142 becomes the dither pattern,
32768 colors are displayed. Therefore, at this time, the display data shown in FIG. 9 is the analog RGB and the synchronization signal 146.
When the key signal 142 shown in FIG. 9 is input to the liquid crystal display 180 of the multi-display 151, the area of the moving image / still image screen 604 is displayed in 32768 colors with the screen configuration shown in FIG. Therefore, the display 603 including the table and the text display and the graphics 602 are displayed in 512 colors.

In this embodiment, the moving image / still image reproducing section 120, the personal computer display system 110, and the overlay control 14 are used.
If 0 is provided in the device on the main body of the personal computer and the multi-display 150 is connected to the outside, the interface can be implemented by adding a key signal to the conventional analog RGB CRT interface.

As another configuration example of this embodiment, RA
RA instead of MDAC143 and RAMDAC114
The D / A converter 1 is used by using the output value of the color designation register used inside the MDAC 143 and the RAMDAC 114.
27 and the A / D converter 163 are omitted, and the output of the display read control 126 and the output of the color designation register are switched by the key signal 142 and input to the multi-gradation control unit 160. All display data may be handled as digital data.

Further, another embodiment of the present invention will be described with reference to FIG.

The embodiment shown in FIG. 10 is a personal computer display system 1
10, a moving image / still image reproducing unit 120, an overlay control unit 140, a multi-tone control unit 160, and a compressed moving image / still image storage medium 130. These are basically constructed similarly to the embodiment shown in FIG. However, since the input interface of the multi-display display 150 is changed from analog to digital, a part of the configuration of the superposition control unit 140 and the multi-gradation control unit 160 is accordingly shown in FIG. There is a difference in configuration from the embodiment shown. Here, the difference will be mainly described.

In the superposition control section 140, the D / A converter used in the embodiment of FIG. 1 is omitted. This is because the output of the display reading control unit 126 is R
This is because each GB is a digital signal of 8 bits. A color lookup table (CLUT) 1400 is provided instead of the RAMDAC 143. Further, as the switching means, for example, the switching means 144a using a 2to1 multiplexer or the like is used.
In the multi-gradation control section 160, the A / D converter 163 used in the embodiment of FIG. 1 is omitted. This is because the input signal is a digital signal.

In such a configuration, the 8-bit RGB digital signals output from the display / readout control section 126 are input to one of the switching means 144a.
Also, the display data from the display control / drawing unit 111 is CL
It is input to the UT 1400 and converted into 8-bit RGB RGB digital data, and the output is input to the other of the switching means 144a. As for the display data selected by the switching unit 144a, the upper 5 bits of each 8 bits of RGB are input to the line memory 164. That is, the address data for 32768 colors is stored in the line memory 164. This address data is input to the gradation pattern ROM 165. The reason for using only the upper 5 bits of each 8 bits of RGB is to reduce the circuit scale of the switching unit 144a.

In this way, according to this embodiment, as shown in FIG.
The superposition control unit 1 that has been executed in the embodiment of
The display data is converted into analog at 40, and the multi-gradation control unit 1
At 60, conversion to digital data can be omitted. Therefore, the circuit configuration can be simplified.

In the above embodiment, a liquid crystal display is used as the multi-display display, but the present invention is
It is not limited to this. Other displays whose display is controlled similarly to the liquid crystal display can be used.

[0075]

According to the present invention, the display contents from a personal computer and the natural image display of a TV or the like can be mixed on a multi-gradation (multicolor) liquid crystal display for personal computer display, and the nature displayed at this time By performing multi-gradation (multi-coloring) control on a portion, it is possible to prevent the color of a natural image from being crushed or a boundary such as a contour line to appear on the display, resulting in an unnatural display.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a multimedia liquid crystal display system of the present invention.

FIG. 2 is a block diagram showing an example of the configuration of a polarity switching and multi-gradation mode switching circuit used in this embodiment.

FIG. 3 is an explanatory diagram illustrating the operation of the polarity switching and multi-gradation mode switching circuit.

FIG. 4 is an explanatory diagram showing key signals and gradation control switching timing.

FIG. 5 is an explanatory diagram illustrating control for performing 32-gradation display on 8-gradation display pixels using a dither method as an example of multi-gradation control.

FIG. 6 is an explanatory diagram showing a configuration example of a display screen.

FIG. 7 is an explanatory diagram showing a personal computer display example.

FIG. 8 is an explanatory diagram illustrating a moving image / still image display example.

FIG. 9 is an explanatory diagram showing a key signal output timing.

FIG. 10 is a block diagram showing the configuration of another embodiment of the multimedia liquid crystal display system of the present invention.

FIG. 11 is a block diagram showing an example of a configuration of a multimedia reproduction system to which the multimedia liquid crystal display system of the present invention is applied.

[Explanation of symbols]

110 ... PC display system, 111 ... Display control / drawing unit,
112 ... VRAM, 120 ... moving image / still image reproducing unit, 12
1 ... Video signal input, 122 ... Video / still image data compression
Decompression control unit, 125 ... Display memory, 126 ... Display reading control unit, 130 ... Compressed moving image / still image storage medium, 140
... overlay control unit, 141 ... key signal generation, 142 ...
Key signal, 146 ... Analog RGB and sync signal, 1
50 ... Multi-display display, 160 ... Multi-gradation control section, 161 ... Clock reproduction, 162 ... Control circuit, 163
... A / D converter, 164 ... Line memory, 165 ...
Gradation pattern ROM, 180 ... Liquid crystal display.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takehiro Yamada Inventor Takehiro Yamada 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside the Hitachi, Ltd. Microelectronics Equipment Development Laboratory (72) Inventor Nobu Makoto Totsuka, Yokohama-shi, Kanagawa 292 Yoshida-cho, Tokyo, Ltd. Inside the Visual Media Research Laboratory, Hitachi, Ltd. (72) Inventor Fumio Inoue, 292, Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture Inside the Video Media Laboratory, Hitachi, Ltd. (72) Inventor Yoshikazu Amano Yokohama, Kanagawa 292 Yoshida-cho, Totsuka-ku, Yokohama, Ltd. AV equipment division, Hitachi, Ltd.

Claims (4)

[Claims] 1. A display system having a multi-gradation display and a multi-gradation control unit for performing multi-gradation display on the display, wherein display data for multi-gradation display is generated and output. 1
Display data generating means, second display data generating means for generating and outputting display data which does not require multi-gradation display, and output data from the first and second display data generating means from one to the other. And a superimposing control unit for inputting to the multi-gradation control unit, the superimposing control unit detects a specific area on the screen instructed in advance, and according to the instruction, the first Regarding the output of the display data generating means and the output of the second display data generating means, means for generating a key signal for switching the currently displayed one to the other, and first display data generating means in response to this key signal. And a switching means for switching display between the output of the second display data generating means and the output of the second display data generating means, and the multi-gradation control section receives the key signal and performs multi-gradation display. A display system comprising means for switching whether or not to display. 2. A display system according to claim 1, wherein the means for generating a key signal is a means for generating a key signal for each display pixel. 3. The display system according to claim 2, wherein the multi-gradation control unit switches between valid and invalid multi-gradation control in display pixel units according to a key signal. 4. The display portion indicated by the key signal according to claim 1, 2 or 3, wherein the display portion is a natural color moving image or a still image,
The other display part is a display system in which the display data is composed of display colors below the display color of the multi-gradation liquid crystal display.