JP2786913B2 - LCD panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to a liquid crystal panel having transparent electrodes arranged in a matrix. The object of the invention is to provide a liquid crystal panel capable of preventing the occurrence of luminance unevenness at low cost. In a liquid crystal panel in which a liquid crystal is sealed between a horizontal transparent electrode and a vertical transparent electrode, and drivers for driving the horizontal transparent electrode and the vertical transparent electrode are arranged in a horizontal direction and a vertical direction, the horizontal transparent electrode and the electric vertical transparent A configuration was adopted in which a terminating resistor having an impedance equivalent to the line impedance was provided at one or both of the electrodes.

The present invention relates to a liquid crystal panel in which transparent electrodes are arranged in a matrix.

The liquid crystal panel has a matrix structure in which horizontal transparent electrodes and vertical transparent electrodes are arranged in a matrix, and liquid crystal is sealed between the horizontal transparent electrodes and the vertical transparent electrodes.

When the liquid crystal panel is small, the signal waveforms at the near end and at the end of the driver for driving the horizontal transparent electrode and the vertical transparent electrode are not so different, and the transmittance of the liquid crystal is almost the same.

However, when the size of the liquid crystal panel becomes large, the signal waveform on the terminal end side becomes more blunt due to the DC resistance and the stray capacitance of the horizontal transparent electrode and the vertical transparent electrode as compared with the near end side of the driver. Shorter,
Brightness unevenness occurs in the liquid crystal panel.

Therefore, it is necessary to prevent luminance unevenness at low cost even if the liquid crystal panel becomes large.

[Prior Art] Conventional liquid crystal panels include, for example, FIGS.
Some are shown in the figure.

4 and 5, reference numeral 1 denotes a horizontal transparent electrode;
Is a vertical transparent electrode, the horizontal transparent electrode 1 and the vertical transparent electrode 2 are arranged in a matrix, and intersecting electrodes constitute display pixels. Liquid crystal 3 is sealed between the horizontal transparent electrode 1 and the vertical transparent electrode 2, and glass plates 4 and 5 are laminated outside the horizontal transparent electrode 1 and the vertical transparent electrode 2, respectively.

Drivers 6 and 7 are connected to one ends of the horizontal transparent electrode 1 and the vertical transparent electrode 2, respectively, and the other ends are open. When a pulse voltage is applied to the horizontal transparent electrode 1 and the vertical transparent electrode 2 by driving the drivers 6 and 7, the liquid crystal 3 rises and light passes.

[Problems to be Solved by the Invention] Generally, when the liquid crystal panel is small, the waveforms on the near end side and the end side of the driver are not so different, and the transmittance of the liquid crystal is almost the same. When the size of the panel becomes large, the direct-current resistance and the stray capacitance of the transparent electrode cause the near end (A) of the driver as shown in FIGS. 6 (A) and 6 (B).
The waveform on the terminal side (B) becomes more dull compared to that of the above, the effective voltage application time of the liquid crystal is shortened (t1> tn), and the brightness unevenness of the liquid crystal panel occurs.

In order to solve this, conventionally, the liquid crystal panel is divided in the horizontal direction or the vertical direction, and the line of the transparent electrode is shortened by adding a driver to prevent the occurrence of luminance unevenness. .

However, in this case, since a driver is added, there is a problem that the cost increases and the circuit configuration becomes complicated.

The present invention has been made in view of such conventional problems, and has as its object to provide a liquid crystal panel capable of preventing the occurrence of luminance unevenness at low cost.

[Means for Solving the Problems] FIG. 1 is an explanatory view of the principle of the present invention.

In FIG. 1, reference numerals 12 and 13 denote horizontal transparent electrodes and vertical transparent electrodes arranged in a matrix, 14 and 15 drivers for driving the horizontal transparent electrodes 12 and the vertical transparent electrodes 13, and 20 and 21 denote the horizontal transparent electrodes. A terminating resistor having an impedance equivalent to the line impedance at each of one or both of the electrode 12 and the vertical transparent electrode 13.

[Operation] In the present invention, a terminating resistor is provided at one or both ends of the horizontal transparent electrode and the vertical transparent electrode so that matching termination is performed at an impedance equivalent to the line impedance. The effective voltage application time of the liquid crystal at the end and the end is the same, and the waveform is also the same. Therefore, it is possible to prevent the occurrence of luminance unevenness of the liquid crystal panel. Further, even if the liquid crystal panel becomes large, it is not necessary to add a driver, so that the cost can be reduced and the circuit configuration does not become complicated.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

2 and 3 are views showing an embodiment of the present invention.

In FIG. 2, reference numeral 11 denotes a liquid crystal panel.
11 has a matrix structure in which horizontal transparent electrodes 12 and vertical transparent electrodes 13 are arranged in a matrix. A liquid crystal (not shown) is sealed between the horizontal transparent electrode 12 and the vertical transparent electrode 13, and a glass plate (not shown) is laminated outside the horizontal transparent electrode 12 and the vertical transparent electrode 13, respectively. Have been.

The horizontal transparent electrode 13 has a driver 14 arranged in a horizontal direction.
Are connected to the vertical transparent electrode 13, and drivers 15 arranged in the vertical direction are connected to the vertical transparent electrodes 13, respectively. By driving these drivers 14 and 15, a pulse-like voltage is applied to the horizontal transparent electrode 13 and the vertical transparent electrode 14.

A selection circuit 16 is connected to the driver 14 in the horizontal direction, and a scanning circuit 17 is connected to the selection circuit 16. A selection circuit 18 is connected to the driver 12 in the vertical direction.
A display memory 19 is connected to 18. The scanning voltage output from the scanning circuit 17 is selected by the selection circuit 16 and drives the driver 14 in the horizontal direction. The signal voltage output from the display memory 19 is selected by the selection circuit 18 and drives the driver 15 in the vertical direction. The horizontal transparent electrode 12 and the vertical transparent electrode 13 are arranged in a matrix, and the intersecting electrodes constitute display pixels. When a voltage is applied to the liquid crystal by driving the drivers 14 and 15, the liquid crystal rises, Passes.

Here, terminating resistors 20, 21 having an impedance equivalent to the line impedance are provided at the respective ends of the horizontal transparent electrode 12 and the vertical transparent electrode 13. The terminating resistors 20 and 21 are matched and terminated with an impedance equivalent to the line impedance.

FIG. 3A shows a horizontal transparent electrode 12 and a vertical transparent electrode 13.
Shows the waveforms at the near ends of the drivers 14 and 15 applied to the circuit, and the effective voltage application time at this time is t1. On the other hand, FIG. 3 (B) shows waveforms at the ends of the drivers 14 and 15 applied to the horizontal transparent electrode 12 and the vertical transparent electrode 13, and the effective voltage application time at this time is tn. Driver 14,15
Have the same effective voltage application time at the near end and at the end (t1 = tn), and have the same waveform. Therefore, the transmittance of the liquid crystal is equal at the near end and the end of the drivers 14 and 15, and the occurrence of luminance unevenness can be prevented.

Further, even if the liquid crystal panel 11 becomes large, it is not necessary to divide the liquid crystal panel 11 in the horizontal direction or the vertical direction and add a driver, so that the cost can be reduced and the circuit configuration becomes complicated. Absent.

In this embodiment, an example in which the terminating resistors 20 and 21 are provided on both the horizontal transparent electrode 12 and the vertical transparent electrode 13 has been described.However, the present invention is not limited to this. When the DC resistance and the stray capacitance are small, one of the horizontal transparent electrode 12 and the vertical transparent electrode 13 may be provided with the terminating resistor 20 or the terminating resistor 21.

[Effects of the Invention] As described above, according to the present invention, a terminating resistor is provided at one or both ends of the horizontal transparent electrode and the vertical transparent electrode. Is the same at the near end and the end of the driver, and it is possible to prevent the occurrence of uneven brightness of the liquid crystal panel. Further, even if the liquid crystal panel becomes large, it is not necessary to add a driver, so that the cost can be reduced and the circuit configuration does not become complicated.

[Brief description of the drawings]

 FIG. 1 is a diagram illustrating the principle of the present invention, FIG. 2 is a diagram showing an embodiment of the present invention, FIGS. 3 (A) and (B) are waveform diagrams of applied voltages, and FIG. FIG. 5 is a sectional view, and FIGS. 6A and 6B are waveform diagrams of applied voltages. In the figure, 11: liquid crystal panel, 12: horizontal transparent electrode, 13: vertical transparent electrode, 14, 15 ... driver, 16, 18 ... selection circuit, 17 ... scanning circuit, 19 ... display memory, 20,21 ... Terminal resistance.

Claims (1)

(57) [Claims] A liquid crystal is sealed between a horizontal transparent electrode (12) and a vertical transparent electrode (13) arranged in a matrix, and the horizontal transparent electrode (12) and the vertical transparent electrode (13) are driven. In a liquid crystal panel in which drivers (14) and (15) are arranged in a horizontal direction and a vertical direction, one of the horizontal transparent electrode (12) and the vertical transparent electrode (13)
Or a liquid crystal panel characterized in that terminating resistors (20) and (21) having the same impedance as the line impedance are provided at both ends.