JPH0446037B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improving the image quality of a television device using a liquid crystal panel.

[Prior art]

Generally, when using a liquid crystal panel to display an image with a large number of pixels, such as a television signal, a matrix of electrodes is formed on the upper and lower substrates of the liquid crystal panel.
One dot at each intersection is defined as one pixel (in the case of color display, R, G, and B dots are one pixel), divided into desired gradations, and voltage is supplied to the pixel. However, as the number of scanning electrodes in a liquid crystal panel is increased using a matrix drive method, the excitation time of the display elements becomes shorter, resulting in a decrease in brightness. If you try to increase the brightness, the display will turn on due to crosstalk and the contrast will deteriorate, so when using dynamic drive, the duty is about 1/128. A multiple matrix method is available as a method of lowering drive duty in order to improve image quality, but multiplexing increases the wiring area and lowers the aperture ratio.

The matrix drive system will be explained based on FIG. Reference numeral 28 denotes a liquid crystal panel composed of matrix electrodes arranged in Y rows and X columns. In synchronization with the scanning method of the television signal, a drive signal for line-sequential scanning along the Y rows is given to the scanning circuit 27, and the signal circuit 26 holds the signal for one horizontal scanning line and scans the X column. Give it to the terminal.

In such a drive and display system, if 1/60 duty is the limit of image quality, for example, the only option is to increase the number of lines to a maximum of 120 on the Y row side or to use a multiple matrix. If the number of lines on the scanning side is limited to 120, this is 1/4 of the horizontal scanning line of the effective television signal, and 3/4 will be thinned out and displayed. Even if a multiplex method is used, if the number of layers is increased to three or four, the open area ratio will further decrease.

〔the purpose〕

An object of the present invention is to reduce the number of scanning lines by thinning out the scan lines due to the drive duty limit by reducing the number of scan lines by two without changing the drive duty.
The purpose is to interpolate to twice as many pixels.

Another purpose is to create a composite signal from both scanning lines between the even field and the odd field of the horizontal scanning line, displaying twice as many scanning lines, and providing a detailed image.

[Purpose of the invention]

FIG. 1 is a block diagram illustrating the driving device of the present invention. A television signal 1 is received and the signal amplified by an amplifier 2 is converted into a digital value separated into desired gradations by an A/D converter 3 and input into a memory controller 4, where the vertical blanking period etc. can also be displayed. If you consider how to use it effectively, digital values can be used for temporary storage.
The data is stored in the RAM 5 and input to the memory controller 4 for one horizontal scanning line to the call signal circuit 7 as required. 7 includes a shift register, a latch driver, and a circuit for converting a digital quantity into a time width gray scale signal. While inputting from the driver to the terminal on the X column side of display 10, the input from TV signal 1
A timing generator 6 is used to obtain the line sequential signal of the LCD panel 10 and the synchronization signal of the memory and signal circuit 7.
Enter. The scanning circuit 8 supplies a line sequential scanning signal for the Y row side of the display 10. The scanning circuit 9 is an interpolated Y _3- line drive circuit for double density. Both the scanning circuits 8 and 9 are synchronized with the signal circuit 7 by a synchronization signal from the timing generator 6.

〔Example〕

FIG. 2 is a connection diagram of the arrangement of panel electrodes and a drive circuit showing one embodiment of the present invention, and FIG. 3 is a drive timing chart. FIG. 4 is a drive timing chart showing another embodiment.

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

In FIG. 2, electrodes Y ₁ -1 on the row side of the panel 10,
The Y ₁ line written Y ₁ -3, Y ₁ -5...corresponds to the display of the horizontal scanning line of the odd field of the television signal, and the Y 1 line written Y ₁ -3, Y _{1 -5} ... wrote Y ₂
The lines are the electrodes that display horizontal scan lines for even fields, and between the Y ₁ and Y ₂ electrodes the Y ₃ line, Y ₃
-1, Y ₃ -2, Y ₃ -3... and insert a complementary line between Y ₁ and Y ₂ , the number of pixels becomes 2,
Clear images can be obtained.

As an example of drive timing, in this example shown in FIG. 3, the RAM 5 for temporary storage in FIG.
When inputting the image 11 of the odd field, the data of the odd field is
Accumulate in RAM5. The driving of the display 10 at the above timing is supplied from the scanning circuit 8 so as to scan the even field lines Y2 line _- by-line. Signal circuit 7
In this case, the even data input one field before is input from the RAM 5 as data synchronized with the even line drive signals 13, 14, and the column electrodes X-1, X-2, . . .
...X-n, even field image signal 1
2, the received signal is the data of the previous odd field stored in the column electrode, and the row electrode is one field in one field that drives the Y ₁ electrode in line sequential scanning like the odd line drive signals 16 and 17. When AC drive is performed and the half cycle is given to the interpolation line Y ₃ as 19, 20, odd field data and even field data are given to Y ₃ , and the combined brightness and color tone are displayed. . Note that the interpolation line drive signal may have a drive waveform of 21 shown by a dotted line. 15 and 18 are half selection periods.

FIG. 4 shows drive timings showing another embodiment, and is an embodiment of the present invention in which the RAM 5 in the block diagram of FIG. 1 is not provided.

When the received image signal is input to the signal circuit and the scanning line is changed, it is temporarily stored in the latch circuit of the signal circuit 7.
It is supplied to column terminals X-1, X-2..., X-n.
The horizontal scanning signal 26 provides a lighting pulse 22 to the display terminal Y ₁ -1 for a timing 27. The column side terminals supply 26 data for 27 times. The data of 28 in the even field is supplied to the column terminal during the timing of 29, and the lighting waveform of Y ₂ -2 is inputted to the row terminal at the timing of 23. Interpolated terminal
24 and 25 are input to Y ₃ and 1/2 of Y ₁ and Y ₂ on the row side from the scanning circuit 9. Since display data 26 and 28 are input to the column side signal, the pixels of the interpolated row side electrode and column electrode obtain the combined luminance and color tone of data 26 and 28.

〔effect〕

As explained above, the Y ₃ line is interpolated to the row electrode of the display panel matrix, and
By adding only the driver, it is possible to synthesize display signals between the horizontal scanning lines of odd and even fields, and the number of pixels can be doubled on the vertical scanning side. This increases resolution and improves image quality.

Also, since the drive pulse of the interpolated line Y ₃ is synthesized by half each of the odd field and even field,
The gradation perceived by the eye is a composite gradation of odd and even fields, making it possible to create continuous image data without performing any calculations or other combinations.

Even when displaying a thinned horizontal signal by reducing the number of lines on the row side due to drive duty, the thinned out horizontal lines can be interpolated depending on the display drive method, and when displaying all 525 horizontal lines, Intermediate signals can be synthesized using interpolated Y ₃ lines, making it an effective means of creating high-quality images.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a driving device of the present invention. FIG. 2 is a diagram showing the relationship between the electrode arrangement and terminals of the panel of the present invention. FIG. 3 is a timing chart showing an embodiment of the present invention. FIG. 4 is a timing chart showing another embodiment. Figure 5 shows the conventional matrix.
A drawing showing the electrodes and drive method of the panel. 10, 28... Display device, 8, 27... Row electrode drive circuit, 9... Interpolation row electrode drive circuit, 7, 26...
...Column electrode drive circuit (signal circuit).

Claims (1)

[Claims] 1 Means for analog/digital conversion of a television signal transmitted by interlaced scanning and temporary storage as a digital quantity, a means for dividing the television signal stored as a digital quantity into gradations and creating a signal for each pixel on a liquid crystal panel. A line (hereinafter referred to as Y _{3 wire} )
A liquid crystal panel is used that is configured to provide a line drive signal that is approximately 1/2 that of an odd line display panel at odd number display timing in interlaced scanning, and approximately 1/2 that of an even line display panel at an even number display timing. Ivy high-definition television equipment.