JPH02144591A - Method for driving flat display - Google Patents

Abstract

PURPOSE:To perform a uniform display on the whole screen of a display by controlling switching element driving signals by means of an external compensation circuit and control circuit which is driven based on the information of the external compensation circuit. CONSTITUTION:An external compensation circuit 12 which compensates characteristics of the drive signal of each switching element and luminance obtained from picture elements corresponding to each switching element and a control circuit 13 which is driven based on the information of the circuit 12 are provided to drive circuit 2 and 3 of a switching array 1. Then the drive signals of the switching elements 1 are controlled by means of the circuits 12 and 13. Therefore, the drive signals to be supplied to each switching element can be adjusted at every switching element and the same luminance can be obtained at all picture elements constituting this display.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for driving a switching array used in a flat display such as a liquid crystal display.

Conventional flat displays include liquid crystal displays, plasma displays, and electroluminescent displays. The switching arrays used in these displays are comprised of millions of switching elements. As shown in FIG. 3, the switching array 1 is driven by a scanning signal driving circuit 2 and a data signal driving circuit 3.

Problems to be Solved by the Invention However, these displays had the following problems.

Switching arrays are manufactured using a method similar to the manufacturing method of semiconductors, but there are often variations in the characteristics of individual switching elements. Therefore, even if the same drive signal is used, the display signal (
output signals) are different.

In addition, even if the characteristics of the switching element are uniform, the characteristics (resistance and capacitance) of the liquid crystal (liquid crystal display), Ar gas (plasma display), or dielectric material (electroluminescence display) to which voltage is applied may vary due to the manufacturing process. Variations often occur during the display assembly process.

Moreover, as the display area becomes larger, the drive signal for driving each switching element becomes different depending on the position of each switching element due to voltage drop.

Due to the above problem, the luminance obtained by each pixel is different even if the same drive signal is used.

In addition, since there is a large variation in brightness obtained from pixels,
It also had the disadvantage of having many defective products and poor yield.

Here, the configuration of a conventional liquid crystal display will be described as a specific example. The schematic diagram is shown in Figure 4, where the panel on the color filter side (A> is a glass substrate 4 with red, green, and blue pixels 5 on it, a transparent fi 6 on top of it, and a polarized light on the opposite side. A plate 7 is attached.The panel CB on the switching array side has switching elements 8 on the glass substrate 4.
A polarizing plate 7 is attached to the opposite side, and a diffusing plate 9 is attached on the polarizing plate 7. Between these two panels is the liquid crystal layer 1.
There is 0. These panels are illuminated with light from a backlight 11 from behind.

This liquid crystal display has the following problems.

1) Switching arrays are manufactured using a method similar to the manufacturing method of semiconductors, but there are often variations in the characteristics of the individual switching elements 8. Therefore, even if the same drive signal is used, the characteristics of the individual switching elements 8 are different from each other. The voltages that can be applied are different.

2) The larger the display area, the more the signals that drive each switching element 8 will differ depending on the position of each switching element due to voltage drop. 3) The film thickness of the color filter pixels 5 will often vary. Light transmission characteristics differ depending on the pixel.

4) Variations in the film thicknesses of the pixels 5 of the color filter and the transparent electrode 6 often occur, so that the thickness of the liquid crystal layer 10 sandwiched between the transparent electrode 6 and the switching element 8 differs. The thickness of the liquid crystal layer 10 also varies depending on the assembly precision of the panel. Therefore, even if the switching elements 8 have the same characteristics, the applied voltages will differ because the characteristics (resistance and capacitance) of the liquid crystal layer 10 corresponding to each switching element differ.

5) Even if the diffuser plate 9 is provided, there is often a distribution in the illuminance irradiated to each pixel by the backlight 11.

Due to the above problem, the luminance obtained by each pixel is different even if the same drive signal is used.

Means for Solving the Problems In order to solve the above problems, the present invention provides a display using a switching array composed of a plurality of switching elements, in which drive signals for each switching element and pixels corresponding to each switching element are used. The driving circuit of the switching array is provided with an external compensation circuit that compensates for the characteristics of the brightness obtained by the switching array, and a control circuit that is driven based on the information of the external compensation circuit, and the switching array is driven by the external compensation circuit and the control circuit. It is characterized by controlling signals.

Operation The present invention uses the above-mentioned means to adjust the drive signal applied to each switching element for each switching element, so that the same brightness can be obtained in all the pixels constituting the display.

Example Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, the external compensation circuit 12 compensates for the characteristics of the drive signal of each switching element and the brightness obtained by the pixel corresponding to each switching element. A control circuit 13 is provided in the scanning signal drive circuit 2 and the data signal drive circuit 3 of the switching array 1.

FIG. 2 shows a schematic diagram of the configuration of a device that inputs information to the external compensation circuit 12 to compensate for the characteristics of the drive signal of each switching element and the brightness obtained by the pixel corresponding to each switching element. is carried out as follows. First, a drive signal from the drive signal generator 14 is sent to the scanning signal drive circuit drive circuit 2 and the data signal drive circuit 3 to operate them. scanning signal drive circuit drive circuit 2;
When the data signal drive circuit 3 is activated, the switching element 8 is driven and the display is turned on. At this time, the luminance obtained from the pixel 5 is read by the optical signal conversion bag W, 15. The signal output from the optical signal converter 15 and the drive signal generated by the drive signal generator 14 are input to the arithmetic processing unit 16 . Information for compensating the characteristics of the drive signal from the drive signal generation device 14 and the brightness read by the optical signal conversion device 15 is processed by the arithmetic processing device 16 and sent to the external compensation circuit input device 17.

The signal is then further input to the external compensation circuit 12.

The external compensation circuit 1 receives information for compensating the characteristics of the drive signal of each switching element and the brightness obtained from the pixel corresponding to each switching element as described above.
2 and the control circuit 13 that is driven based on the information of the external compensation circuit 12, as shown in FIG. By controlling the drive signal of the switching element, it is possible to adjust the brightness obtained from the pixel corresponding to each switching element.

In the above embodiments, the case of a liquid crystal display has been described, but the present invention is not limited to this, and it is clear that it can be applied to a flat display having a plurality of switching elements using other methods, and is effective.

Effects of the Invention By using the flat display driving method of the present invention, the brightness obtained from each pixel can be adjusted. Therefore, uniform display can be performed over the entire display surface. In addition, since the brightness obtained from each pixel varies greatly and conventionally defective devices can be used, the yield can be improved and the present invention has a great practical effect.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the switching array of the present invention and its drive circuit, and FIG. 2 is a schematic diagram of the switching array of the present invention and its driving circuit. A schematic diagram of the configuration of a device for inputting characteristics to an external compensation circuit, FIG. 3 is a schematic diagram of a conventional switching array and its driving circuit, and FIG. 10 is a schematic diagram of the configuration of a conventional liquid crystal display. DESCRIPTION OF SYMBOLS 1... Switching array, 2... Scanning signal drive circuit, 3... Data signal drive circuit, 8... Switching element, 12... External compensation circuit, 13... Control circuit.

Claims (3)

[Claims] (1) In a display using a switching array composed of a plurality of switching elements, external compensation compensates for the characteristics of the drive signal of each switching element and the brightness obtained from the pixel corresponding to each switching element. A flat display characterized in that the driving circuit of the switching array is provided with a control circuit driven based on information of the circuit and the external compensation circuit, and the external compensation circuit and the control circuit control the driving signal of the switching element. Driving method. (2) The method for driving a flat display according to claim 1, wherein the scanning signal of the switching element is adjusted by an external compensation circuit and a control circuit controlled based on information from the external compensation circuit. (3) The method for driving a flat display according to claim 1, wherein the data signal of the switching element is adjusted by an external compensation circuit and a control circuit controlled based on information from the external compensation circuit.