JPS6253990B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drive device for a matrix display device, and in particular to a matrix display device configured for broadcasting areas with a large number of scanning lines. It is an object of the present invention to provide a drive device capable of displaying television images without any noise.

For example, in a television image broadcast area with 625 scanning lines, such as Germany, 50 scanning lines are included in the vertical retrace period, so the remaining 575 are effective scanning lines. Therefore, the XY matrix panel, which is the main part of the display device, has a horizontal pixel count of around 560 or 560/N (N is an integer), and the row electrodes (X electrodes) also have the same number of picture elements. It is common to configure them with the same number. Here, a conventional drive device will be explained using an example of an XY matrix panel 1 when N=2, that is, the number of X electrodes is 280.

The video signal input to terminal 2 is sent to synchronization separation circuit 3.
A composite synchronizing signal is obtained, and a vertical synchronizing signal shown in FIG. 2a and a horizontal synchronizing signal shown in FIG. 2b are obtained in the V/H separation circuit 4. Next, the control signal generating circuit 5 generates a vertical scanning start pulse as shown in FIG. Furthermore, the horizontal synchronization signal b is sent to the X electrode drive circuit 6.
_{If the} clock signal _of X
Pulses are applied to the electrodes, XY matrix panel 1
is scanned. On the other hand, in the Y electrode drive circuit 7, which mainly consists of a sample and hold circuit, the serial video signal is converted into parallel video signals for a total of several Y electrodes, and each converted video signal is simultaneously sent to the corresponding Y electrode. applied. And X
The scanning panel applied to the electrodes sequentially scans the line at a
Pixel 8 is selected in time (line sequentially) and the panel is driven. Note that in this conventional example, the number of X electrodes is
Since it is 280 lines, it is not interlaced.

Next, a case will be described in which this XY matrix panel 1 receives Japanese television broadcasting and displays images. In Japan, there are 525 scanning lines, and 42 are included in the vertical retrace period, so the remaining 483 are the effective number of scanning lines. When driving this XY matrix panel, 12 does not perform interlacing, so to display one image, 483 lines/2≒
It is sufficient to have 241 X electrodes. Therefore, if an image is displayed using the XY matrix panel 1 with 280 X electrodes shown in Figure 1, the XY matrix panel 1 will have 280-241=39 X electrodes.
There is no image to display in some parts of the screen.

FIG. 3 shows details of the X electrode drive circuit 9 in one embodiment of the drive device of the present invention. F.F1, FF
FF2, FF3, . Terminal 10 is a clock signal input terminal as shown in Figure 2b.
horizontal synchronization signal is added. Terminal 11 is a serial input terminal to which a pulse signal obtained by control signal generation circuit 5 is applied. Terminal 12 is a switching terminal for receiving and displaying images in broadcast areas with different scanning lines.
In broadcasting areas with 625 scanning lines like Germany, terminal 12 is set to "L", and when receiving in broadcasting areas with 525 scanning lines like Japan and America, the voltage is set to "H". applied.

First, we will explain how to display a television broadcast image with 625 scanning lines. The data of the vertical scanning start pulse of FIG. 2c applied to the serial input terminal of terminal 11 is shifted to the right one by one each time the clock pulse of FIG. 2b of terminal 10 is input. Then, from the outputs of each stage from FF1 to FF7, pulses whose phase is delayed by one horizontal scanning period are obtained as shown in Fig. 2 d, e, f, g, h, i, and j, and the corresponding X electrodes X ₁ to join X ₇ . Since the terminal 12 is now "L", the output "H" of the inverter 16 is sent to the NAND circuit 1 along with the output j of FF7.
3, and as the output of this NAND circuit 13, a pulse signal whose phase is inverted from the signal shown at j is obtained. On the other hand, "L" of the terminal 12 and the output i of the FF6 are applied to the NAND circuit 14, and an "H" output is obtained as its output. This output “H” and the above
The output of the NAND circuit 13 is applied to the NAND circuit 15, and the pulse signal shown in FIG. 2j is again obtained as its output. This pulse signal j is F, F, 8
The pulses shown in FIG. 2 are obtained from FF8 and FF9 by shifting to the right according to the clock signal, and are applied to the corresponding X electrodes _X8 and _X9 . As described above, the XY matrix panel 1 is scanned, and a TV broadcast image with 625 scanning lines is displayed over the entire surface.

Next, the operation when displaying a television broadcast image with 525 scanning lines will be explained. From FF1 to F, F.
The operation up to 7 is the same as above, X ₁ , X ₂ , X ₃ ,
d _, e, _f , _{g ,}
Pulses h, i, and j are added. At this time, terminal 12
is switched to "H", and the output of the inverter 16 becomes "L". This “L” output and FF7
The output j of is applied to the NAND circuit 13, and the NAND
The output of the circuit 13 becomes "H". On the other hand, the output i of the FF 6 and "H" of the terminal 12 are applied to the NAND circuit 14, and a pulse signal having the phase inverted of the signal shown at i is obtained as an output. This output and NAND circuit 13
The output “H” is added to the NAND circuit 15.
At the output of the NAND circuit 15, the pulse signal shown at i is again obtained. This pulse signal i becomes the input data of FF8 and is read by the clock signal.
The output of F.8 is the same as the output of FF7, the pulse signal shown in j is obtained, and this _pulse signal is
Add to the electrode. And this signal j is the next stage FF
9, and is sequentially shifted to the right by the clock signal. And FF9, FF
10... Obtain k, l... as outputs, and X ₉ ,
X ₁₀ ...Added to the electrode. As described above, the panel 1 is scanned, and a TV image with 525 scanning lines is displayed on the panel 1.

Note that the clock signal at terminal 10 is connected to inverter 1.
The voltage applied to FF8 via 7 and 18 is FF
By delaying the phase of the clock signal by using inverters 17 and 18, the phase delay of the data caused by the output data of FF 6 or FF 7 being added via the NAND circuits 14 and 15 or the NAND circuits 13 and 15 to the input end of FF 8 is eliminated. This is to ensure that data is read into F.F8.

According to the above embodiment, in a broadcasting area with 625 scanning lines like Germany, by keeping the terminal 12 at "L", the X electrodes X ₁ , X ₂ , X ₃ , X ₄ ,
X ₅ , X ₆ , X ₇ ... in Figure 2 d, e, f, g,
Waveforms h, i, j... are applied at the timing of one horizontal scanning period, and scanning is performed up to the 280th X electrode _X280 . In this case, since interlacing is not performed as described above, one image is displayed on the matrix panel 1 having 280 X electrodes.

Next, the number of scanning lines is 525, such as Japan and America.
In the main broadcast area, by setting the terminal 12 to "H", the X electrodes _X1 , _X2 , _X3 , _X4 , _X5 , _X6 , _X7
Similarly to the above, the waveforms d, e, f, g, h, i, and j are added, and the signal j, which is the same as X ₇ , is applied to the X electrode X ₈ instead of k. Then X ₉ , X ₁₀ ...
K, l... signals are sequentially applied to _X14 , and the X electrode
The same signal as X ₁₄ is also applied to X ₁₅ again. In this way, the same pulse signal is applied to the 7th and 8th electrodes for each of the 8 X electrodes.
A pulse is applied to the 280th X electrode at the timing of the 240th scanning line. In the current broadcasting area with 525 scanning lines, the effective number of scanning lines is 483, and since interlacing is not performed, one screen has approximately 240 scanning lines.
This is the main function, and the panel 1, which has 280 X electrodes between the upper and lower sides, can now display images.

Of course, it is necessary to change the position of the vertical scanning start pulse c generated based on the vertical synchronizing signal a applied to the terminal 11 each time the number of scanning lines changes. Furthermore, it is sufficient to simply change the sampling frequency in the Y electrode drive circuit 7 as well.

The above embodiment is suitable for an IC configuration, and includes NAND circuits 13, 14, 15, and an inverter 1.
Addition of 6, 17, 18, etc. is easy. Furthermore, in the above example, the same pulses are applied at regular intervals such as to X electrodes X ₇ and X ₈ and X _{14 and} That should be obvious.

Therefore, if you assume in advance a broadcasting area with two or more different numbers of scanning lines and place the above NAND circuits in combination, for example in France there is a broadcasting area with 819 scanning lines. However, in this case, by configuring a matrix panel with the appropriate number of X electrodes according to the area of the number of scanning lines, it is possible to achieve
It is possible to project even books (books) etc. with almost no loss in image quality. This is exactly the same when interlacing is performed by providing twice the number of X electrodes as described above.

As described above, according to the present invention, the number of N flip-flops is the same as the number of X electrodes connected to the X electrode, and the outputs of two adjacent flip-flops are N flip-flops are cascade-connected to drive the N X electrodes as an N-stage shift register, or the switch group is selected and the N-
By configuring an M-stage shift register and driving M of the N X electrodes at timings that overlap with the adjacent ones, it is possible to transmit information for one screen without disturbing the image even in broadcast areas with different numbers of scanning lines. It is possible to provide an excellent drive device for a matrix display device that can display on a predetermined type of display section.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the main parts of a matrix display and its driving device, Fig. 2 is a waveform diagram for explaining one embodiment of the present invention, and Fig. 3 is a block diagram of the main parts of this embodiment. be. DESCRIPTION OF SYMBOLS 1... Matrix panel, 5... Control signal generation circuit, 7... Y electrode drive circuit, 9... X electrode drive circuit, 12... Terminal, 13, 14, 15...
NAND circuit, 16, 17, 18...inverter,
FF1, FF2...F.F280...Flip-flop, _X1 , _X2 ... _X280 ...X electrode.

Claims (1)

[Claims] 1. A matrix display panel that selects and displays pixels line by line using a matrix of X electrode groups and Y electrode groups, an X electrode drive circuit that scans and drives the X electrode group, and a Y electrode drive circuit that drives the Y electrodes. The X electrode drive circuit is inserted at M locations between the N flip-flops, the same number of which are arranged and connected to the N flip-flops, and the N flip-flops. It has a group of switches for switching the outputs of two matching flip-flops to be the same, and means for controlling the group of switches, and when the number of scanning lines of one image to be displayed is N, the number of flip-flops is are connected in cascade to drive N X electrodes as an N-stage shift register, and when the number of scanning lines of one image to be displayed is N-M, the switch group is selected and the N-M stage shift register is connected. 1. A driving device for a matrix display device, comprising a shift register, and driving M out of N X electrodes with outputs that overlap with adjacent ones.