JP3262175B2 - LCD driving method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line driving method for video-related equipment such as a television receiver using a liquid crystal dot matrix display.

[0002]

2. Description of the Related Art In a conventional liquid crystal driving method, line electrodes are taken out every other line on the left and right sides of a liquid crystal panel 2 as shown in FIG. 4, and odd odd fields are driven by an output pulse Fo of an odd line drive circuit 1a, and even odd fields are driven. Are driven by an even-numbered line drive circuit 1b output pulse Fe. FIG.
(A), (b), and (c) show the output pulse Fo of the odd-numbered line drive circuit 1a and the output pulse Fe of the even-numbered line drive circuit 1b with respect to the vertical synchronization signal Vsync and the horizontal synchronization signal Hsync at the time of scanning the odd odd field and the even even field. Shows timing. As the liquid crystal becomes higher definition, screen flicker becomes conspicuous, and digital scale processing using a line memory or the like is required to perform non-interlaced scanning so that flicker is not conspicuous, thus increasing the circuit scale. When ordinary two lines are simultaneously driven for non-interlaced scanning, two lines indicated by arrows in FIG. 6A are simultaneously driven by the same signal in the odd odd field on the liquid crystal panel 2, and the even number is driven. In the even field, two lines indicated by arrows ← in FIG. 6B are simultaneously driven by the same signal.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the prior art, and has a cost advantage for high-definition image display in which non-interlaced scanning is performed without using a large-scale integrated circuit such as a line memory. The present invention provides a liquid crystal driving method.

[0004]

SUMMARY OF THE INVENTION The present invention provides a non-interactive circuit for simultaneously driving a plurality of lines with an odd line drive circuit by delaying the horizontal scanning timing by one line for each even field on the even line drive circuit side of the liquid crystal panel. It features race scanning.

[0005]

As shown in FIG. 1, the display liquid crystal panel 2, the odd odd line drive circuit 1a of the liquid crystal panel 2, and the even number even
It is composed of a line drive circuit 1b, a shift register 3a of an odd line drive circuit 1a, a shift register 3b of an even line drive circuit 1b, an odd / even field discriminating circuit 4, a D-flip-flop circuit 5, and a switch circuit. The horizontal scanning timing is delayed by one line according to the discrimination signal 7 output from the field discrimination circuit 4 to D-
The output signal 8 of the flip-flop circuit 5 is selected, and two lines indicated by arrows in FIG. 3B are simultaneously driven by the same signal via the shift register 3b.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to perform non-interlaced scanning, two lines are simultaneously driven by the same signal. 1 is a liquid crystal panel for image display, 1a is an odd line drive circuit for outputting a drive pulse Fo for driving each odd line of the liquid crystal panel 2, and 1b is a drive pulse for driving each even line of the liquid crystal panel 2. An even-line drive circuit for outputting Fe, 3a and 3b are shift registers of odd-line and even-line scanning pulses by a control signal such as a reference clock pulse CK and a start pulse SP for starting odd / even field scanning, respectively, and 4 is a vertical synchronizing signal Vsy.
an odd / even field discriminating circuit which inputs nc and the horizontal synchronization signal Hsync and outputs an even field discriminating signal 7;
Reference numeral 5 denotes a D-flip-flop circuit for delaying the start pulse SP for starting field scanning by one line, and reference numeral 6 denotes a switch circuit for selecting and outputting a start pulse SP of an odd / even field in accordance with a discrimination signal 7 output from the field discrimination circuit 4.

FIGS. 2A and 2B each show an even number even.
This is the timing of the drive pulse Fe when scanning the odd and even fields of the line drive circuit 1b.
To drive two lines simultaneously, the odd line drive circuit 1a and the even line drive circuit 1b may be operated by the same signal. However, in this case, in the odd field scanning, the timing shown in FIG. 3A → the line drive of display is not a problem, but in the even field, the arrow shown in FIG. In addition, the same signal is applied to the same line in both odd and even fields, so that pairing occurs and the image quality deteriorates. Therefore, as shown in FIG. 1, the field discriminating circuit 4 and the D-flip-flop circuit 5 are connected to the shift register 3b start pulse SP input circuit on the even line drive circuit 1b side.
And a switch circuit 6.

That is, the switch circuit 6 is switched from the terminal a side to the terminal b side during odd field scanning by the discrimination signal 7 output from the field discriminating circuit 4 during even field scanning, and the horizontal scanning timing of the even line drive circuit 1b is set to 1 By selecting the output signal 8 of the D-flip-flop circuit 5 that delays the line, and placing the virtual drive 1D indicated by the dotted line in FIG. 2B, the timing of the output Fo of the odd-numbered line drive circuit 1a is adjusted together with the timing of FIG. The line drive timing indicated by the arrow shown in ()) is displayed, and a non-interleaved scanning high-definition image without pairing is displayed. Also, at the time of odd field scanning, the switch circuit 6 is switched to the terminal "a" so that the timing of the output Fo from the odd line drive circuit 1a is changed to the arrow shown in FIG. Perform a scan.

[0009]

As described above, the present invention makes it possible to simultaneously drive a plurality of lines with the odd line drive circuit by delaying the horizontal scanning timing by one line for each even field in the even line drive circuit of the liquid crystal panel. Further, it is possible to realize a cost-effective liquid crystal driving method for high-definition image quality display that achieves non-interlacing without using a large-scale integrated circuit such as a line memory.

[Brief description of the drawings]

FIG. 1 is a block diagram of a non-interlaced scanning liquid crystal driving method by simultaneously driving a plurality of lines.

FIG. 2 is a timing diagram of an odd / even field in the even line drive of FIG. 1;

FIG. 3 is a diagram showing a line drive timing of odd / even fields in the liquid crystal panel of FIG. 1;

FIG. 4 is a block diagram for explaining a conventional liquid crystal driving method.

5 is a timing chart of a liquid crystal panel odd / even line drive in an odd / even field of FIG. 4;

FIG. 6 is a diagram showing a line drive timing of odd / even fields in the liquid crystal panel of FIG. 4;

[Explanation of symbols]

 1a Odd line drive circuit 1b Even line drive circuit 2 LCD panel 3a Odd line shift register 3b Even line shift register 4 Odd / even field discrimination circuit 5 D-flip-flop circuit 6 Switch circuit

Claims (1)

(57) [Claims] In a liquid crystal dot matrix display comprising an odd line drive circuit and an even line drive circuit, a circuit for discriminating between an odd field and an even field and a start pulse are delayed by a reference clock pulse.
D-flip-flop circuit and start pulse or base
The start pulse delayed by the quasi-clock pulse is
Select according to the discrimination result of the discrimination circuit, and select the selected output
The switch circuit to be supplied to the even line drive circuit
And when the determination result of the determination circuit is an odd field,
Select the pulse, and if the discrimination result is an even field,
Selects start pulse delayed by quasi-clock pulse
Switch the switch circuit for each field so that
A non-interlaced scanning method in which two adjacent lines are simultaneously displayed with the same signal .