JPH0732473B2 - Liquid crystal display - Google Patents

Description

The present invention relates to a driving method of a liquid crystal video display device.

A circuit diagram of a conventional liquid crystal video display device is shown in FIG. 101 is a source side driver, 102 is a liquid crystal video display panel, 103 is a gate side driver, 104 is a shift register, 105 is a source side clock input terminal, 106 is a source side data input terminal, 107 is a video signal input terminal, 108
Is an analog switch, 109 is a pixel, 110 is a shift register, 111 is a gate side data input terminal, 112 is a gate side clock input terminal, 113 is an analog switch, 114 is a capacitor, 115 is a liquid crystal, and 116 is a common electrode. With conventional LCD video display devices, the horizontal resolution (number of pixels)
Can be changed to some extent by increasing the clock frequency of the driver on the source side. However, the vertical resolution (number of pixels) is restricted by the television signal system. Furthermore, conventional liquid crystal video display devices do not formally perform interlace scanning. Ie 1
The signal of the field is written in the pixel, and in the second field, it is written in the same pixel in an overlapping manner. That is, the vertical resolution is halved. As described above, the conventional liquid crystal video display device has a drawback that the vertical resolution is not good.

The present invention eliminates such drawbacks, and an object thereof is to improve the vertical resolution and obtain sufficient display quality even on a large screen.

FIG. 2 is a drive system diagram of the liquid crystal video display device of the present invention. The liquid crystal video display device of the present invention has about 400 to 500 timing lines corresponding to interlaced scanning. In a liquid crystal video display device, it is not possible to select every other line by interlaced scanning. This is because it is necessary to apply a voltage with an AC waveform of about 30 Hz to the liquid crystal. Therefore, in the present invention, as shown in FIG. 2, for each pixel in the odd field,
……… and select two timing lines and write,
In the even field, the signal inverted with respect to the common electrode potential is ...
Write on the timing line by shifting two lines.
Conventionally, the average value of and is displayed, but in the present invention, the average value of ,,, and is displayed, so that the resolution in the vertical direction is improved as compared with the conventional case. Each pixel is displayed as the average value of the odd field and the even field as in the conventional case, but the number of timing lines is doubled, which is sufficient for home use and has no frame memory. Since the liquid crystal can be driven by alternating current, the peripheral circuit is also simple.

FIG. 3 is a circuit diagram of the liquid crystal video display device of the present invention. 301 is an even / odd field signal input terminal, and 302 is an analog switch (which is an even / odd changeover switch). 30
The analog switch of 2 is the lower side in the odd field,
It is controlled by the even / odd field signal input of 301 so that it is turned on in the case of an even field. In synchronization with the even / odd field signal, the source side driver is supplied with a positive polarity video signal of an even field and a negative polarity video signal (with respect to a common electrode potential) of an odd field.

FIG. 4 shows another embodiment of the present invention. In this embodiment, the analog switch 302 is set to the liquid crystal video display panel 102.
By incorporating it in the side, the number of connections between the liquid crystal video display panel 102 and the gate side driver 103 can be suppressed to the same number as the conventional number.

Then, the present invention, by having such a configuration, in a liquid crystal display device having 400 to 500 scanning lines, it is possible to perform interlaced scanning with a very simple configuration while maintaining high image quality, A high quality display device can be achieved. Especially when the liquid crystal display device supports interlaced scanning,
If a video signal is not applied at a certain frequency or higher, flicker occurs and the image quality becomes extremely poor.
By selecting a pair for each scanning line and shifting the two pairs for the odd field and the even field, a signal is applied to every scanning line for every scanning line without the need for a field memory or the like. Is used to display the average value of the odd and even fields.

There is some image quality degradation due to the averaged display,
The number of scanning lines can be doubled by simply adding a switching element that selects two scanning lines at the same time without the need for a conventional field memory or the like, and the image quality can be dramatically improved. The effect can be great. In particular, when considering use in a general household or the like, the effect of doubling the scanning lines is very large, and the deterioration of image quality due to displaying the average value is not a problem. Rather, the effect of being able to supply a high-quality liquid crystal display device at low cost is more significant.

Further, as an application of the present application, if the horizontal resolution is increased by a conventional method (for example, the number of horizontal pixels is increased and the clock frequency is increased) and the horizontal resolution is also increased, a larger-sized high-quality display device can be easily manufactured. Can be achieved.

The drive system of the present invention is also effective in a time-division drive liquid crystal video display device which is not an active matrix panel.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a conventional liquid crystal video display device. FIG. 2 is a drive system diagram of the liquid crystal video display device of the present invention. 3 and 4 are circuit diagrams of the liquid crystal video display device of the present invention. 101 …… Source side driver 102 …… LCD video display panel 103 …… Gate side driver 104 …… Shift register 105 …… Source side clock input terminal 106 …… Source side data input terminal 107 …… Video signal input terminal 108 …… Analog switch 109 …… Pixel 110 …… Shift register 111 …… Gate side data input terminal 112 …… Gate side clock input terminal 113 …… Analog switch 114 …… Capacitor 115 …… Liquid crystal 116 …… Common electrode 301 …… Even and odd field Signal input terminal 302 …… Analog switch

Claims (1)

[Claims] 1. A liquid crystal is enclosed between a pair of substrates, scanning lines corresponding to lines of odd fields and scanning lines corresponding to lines of even fields are alternately arranged on the substrates, and the scanning lines are arranged. In a liquid crystal display device having signal lines arranged so as to form a matrix and having pixels selected by the scanning lines and the signal lines, in odd fields, scanning lines corresponding to odd fields and The scanning lines corresponding to the even fields adjacent to the scanning lines corresponding to the odd fields are paired one by one, and the scanning lines are selected, and the video signals of the same odd field are supplied to the selected two scanning lines. In addition to applying the voltage, in the even field, an odd number of the scanning line corresponding to the even field and the scanning line corresponding to the odd field adjacent to the scanning line corresponding to the even field It is characterized in that the other scanning line which has not become a pair at the time of the field is paired and the scanning line is selected, and the same even field video signal is applied to the two selected scanning lines. Liquid crystal display device.