JPH055337B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Industrial Application Field The present invention relates to a liquid crystal display device, and in particular,
The present invention relates to a matrix type liquid crystal display device that performs divisional driving.

(b) Prior Art In recent years, liquid crystal display devices have been widely used as display devices for various devices including display terminals for small computers because of their small size, light weight, thinness, and low power consumption. In addition, as display devices can adequately handle the diversification of display information, there are demands for LCD panels to expand their information capacity and improve visibility.
Studies on cell structures, electrode configurations, driving methods, liquid crystal materials, etc. are being actively conducted in various fields.

FIG. 4 is an example of a block diagram of a conventional two-part liquid crystal display device. In the figure, 1 is a liquid crystal panel, _Y1 to _Y5 , _Y1 ' to Y5' are scanning electrodes, and _X1 to _Y5 ' are scanning electrodes.
X ₁₂ , X ₁ ′ to X ₁₂ ′ are signal electrodes. In addition, here N
In the ×M XY matrix, N=10, M=12
An example is given of the case of Usually, the LCD panel is
In order to increase the display capacity, the signal electrodes are separated by X ₁ to
By dividing the screen into two parts, X ₁₂ and X ₁ ' to _{X 12} ', and driving the top and bottom simultaneously in a time-division manner, it maintains the display quality of an LCD panel equivalent to N/2 division, while maintaining the display quality of an LCD panel with N scanning electrodes. The electrode configuration is such that high resolution can be obtained. Further, 4 is a scanning electrode driver, and 2, 2' and 3, 3' are upper and lower signal electrode drivers, respectively, each of which has its own data signal line for odd and even signal electrodes.
By using one set of two signal electrode drivers in this manner, the data transfer frequency is reduced and power consumption is reduced. 6 is a signal for the upper screen odd-numbered signal electrodes, 6' is a signal for the upper screen even-numbered signal electrodes, 7 is a signal for the lower screen odd-numbered signal electrodes, and 7' is a signal for the lower screen even-numbered signal electrodes. The data signals and various timing signals for the upper and lower screens are sent out and controlled by the controller 5. Furthermore, since the number of scanning lines on the upper and lower screens of the liquid crystal panel 1 is five each, the number of time divisions is five, resulting in so-called 1/5 duty driving.

(c) Problems to be Solved by the Invention In such a conventional matrix panel that is divided into upper and lower halves, the signal electrode pattern is completely divided in the middle as shown in FIG. There are drawbacks.

In other words, when displaying an image or character, the frequency components of the drive waveform differ between the upper and lower screens, and the drive waveform is distorted due to the effects of electrode resistance, driver resistance, and display pixel capacitance. arise. As a result, the effective voltage value applied to a lit pixel or a non-lit pixel differs slightly between the upper and lower screens. Conventional matrix liquid crystal panels that are divided into upper and lower halves are completely divided into upper and lower parts at the center of the screen, so due to the difference in effective voltage values mentioned above, the upper and lower divisions stand out and display a homogeneous image across the entire screen. I can't. One way to solve this problem is to increase the film thickness of the transparent electrode to lower the electrode resistance, but this method reduces the transmittance of the transparent electrode, which reduces the brightness of the entire screen. The screen becomes darker, and the upper and lower screen divisions are
Unlike inside the screen, there are no transparent electrodes, so
This is recognized as a "white straight line" that divides the upper and lower screens, resulting in a significant deterioration in display quality.

This invention has been made in consideration of these circumstances, and it is an object of the present invention to provide a liquid crystal display device with good display quality in which the screen quality does not change even if the signal electrode is divided into two parts. .

(d) Means for Solving the Problems This invention forms a screen by orthogonally intersecting a parallel first band-shaped electrode group and a parallel second band-shaped electrode group, and
In a liquid crystal display device having an upper and lower half-divided matrix panel in which the electrode group is divided into two for the upper screen and the lower screen at approximately the center of the screen, division of the first strip-shaped electrode on the upper screen and the first strip-shaped electrode on the lower screen is performed. The liquid crystal display device is characterized in that the second band-shaped electrode group is located between different electrode arrangements of the second band-shaped electrode group.

(E) Effect The divided portions of the first strip electrodes of the upper and lower screens are arranged between different electrodes of the second strip electrode group, and the divided ends of the signal electrodes are not located in a straight line, so the display characteristics of the upper and lower panels are Even if the images are slightly different, the upper and lower screens are mixed at the dividing section to make the entire screen homogeneous.

(F) Embodiments The present invention will be described in detail below based on embodiments shown in the drawings. Note that this invention is not limited to this.

FIG. 1 is a block diagram showing one embodiment of the present invention. In the liquid crystal panel 1a, Y ₁ to Y ₆ and Y ₁ ′ to _{Y 4} ′ are scanning electrodes, and upper screen signal electrodes X ₁
~ _X12 and lower screen signal electrodes _X1 '~ _X12 ' are divided part 8
a, 8b, and upper screen (odd number) signal electrodes X ₁ ~
Both X ₁₂ and the lower screen (even number) signal electrodes X ₂ ′ to X ₁₂ ′ are arranged to intersect with scanning electrodes Y ₅ and Y ₆ .
5a is a controller that generates data signals and various timing signals for the signal electrodes _X1 to X, _X1 ' to _X12 '. The number of scan electrodes on the liquid crystal panel 1a is 10, of which 6 scan electrodes Y ₁ to _{Y 6} are used as upper screen scan electrodes, and 4 scan electrodes Y ₁ ′ to Y ₄ ′ are used as lower screen scan electrodes. , are connected to the scanning electrode driver 4, respectively. The other configurations are the same as in FIG. 4.

FIG. 2 is a time chart showing an example of a signal for driving the liquid crystal display device of FIG. 1, and the number of time divisions is 6, which is a so-called 1/6 duty drive.

Figure 2A shows the voltage waveform of the wave height direct _V1 applied to the scanning electrodes _Y1 to _Y6 and Y1 _' to _Y4 ', and a of the figure B shows the voltage waveform of the upper screen (odd number) signal electrodes _X1 to _X11. The voltage waveform applied to the upper screen (even number) signal electrode b in the same figure B
The voltage waveform applied to X ₂ to _{X 12} , a in the same figure C is the voltage waveform applied to the lower screen (odd number) electrodes X ₁ ′ to X ₁₁ ′, b in the same figure C is the lower screen (even number) electrode X ₂ ′～
This is the voltage waveform applied to X ₁₂ ′. Here, the peak value of the voltage applied to each signal electrode is V ₂ ,
The liquid crystal is driven by setting V ₁ =√V ₂ (N is the number of scanning lines) based on the optimum voltage averaging method.

Furthermore, since the upper screen (even number) signal electrodes X ₂ to X ₁₂ and the lower screen (odd number) signal electrodes X ₁ ′ to X ₁₁ ′ do not intersect with the scan electrodes Y ₅ and Y ₆ , the scanning electrodes Y ₅ and Y ₆ in some cases,
_{Dummy data ( V 2}
or -V ₂ ) is applied (A in FIG. 2B, B in FIG. 2C).

Furthermore, since the lower screen (even number) signal electrodes X ₂ ′ to X ₁₂ ′ intersect with scanning electrodes Y ₅ , _{Y 6} ,
When scanning Y ₆ , the lower screen ( _even number) signal electrode
A signal for the upper screen (even number) signal electrodes X ₂ to X ₁₂ is applied to X ₁₂ ' (C in FIG. 2). The above data signals are controlled within the controller 5' and sent to the upper and lower drivers 2, 2' and 3, 3'.

In addition, with this driving method, the duty ratio is slightly smaller than that of the conventional method, but when the number of scanning lines is extremely large (approximately 60 or more), the difference in operating margin due to the difference in duty ratio is small. It almost never causes a deterioration in the display quality of the screen.

As a result of display experiments by adapting this liquid crystal display device to an actual upper and lower split XY matrix panel (128 x 128 dots), the "white straight line" that separates the upper and lower screens, which is a drawback of the conventional method, was not recognized, and the screen It was confirmed that uniform image display could be obtained over the entire area.

FIG. 3 is a diagram corresponding to the liquid crystal panel of FIG. 1 showing another embodiment of the present invention, in which the signal electrode has three types of divided portions 8a, 8b, and 8c, but is similar to the embodiment shown in FIG. effect can be obtained.

(G) Effects of the Invention According to the present invention, a liquid crystal display device is provided in which the screens of the divided parts of the upper and lower halves of the matrix panel are made homogeneous, and the display quality is excellent.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing one embodiment of this invention, Fig. 2 is a time chart showing various signals of the embodiment of Fig. 1, and Fig. 3 is an explanation showing a liquid crystal panel of another embodiment of this invention. Figure 4 shows the first example of the conventional example.
FIG. 1a...Liquid crystal panel, 2, 2'...Upper screen signal electrode driver, 3,3'...Lower screen signal electrode driver, _X1 ~ _X12 ...Upper screen signal electrode, _X1 '~
X ₁₂ ′...Lower screen signal electrode, Y ₁ ~ Y ₆ , Y ₁ ′ ~ _{Y 4} ′...
...Scanning electrode, 4...Scanning electrode driver, 5...
controller.

Claims (1)

[Claims] 1 A screen is formed by orthogonally crossing a parallel first band-shaped electrode group and a parallel second band-shaped electrode group, and the first electrode group is divided into two parts for the upper screen and the lower screen at approximately the center of the screen. A liquid crystal display device having a matrix panel divided into upper and lower halves, characterized in that the dividing portion of the first band-shaped electrode of the upper screen and the first band-shaped electrode of the lower screen is located between different electrode arrangements of the group of second band-shaped electrodes. LCD display device.