Pixel circuit and display device

A technology for pixel circuits and display devices, which is applied to identification devices, static indicators, instruments, etc., and can solve problems such as average potential reduction, display quality reduction, and pixel data voltage fluctuations.

Inactive Publication Date: 2012-06-13
SHARP KK
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, when the refresh frequency is lowered, the pixel data voltage held in the pixel electrode fluctuates due to the leakage current of the TFT.
In addition, the average potential in each frame period also decreases, so this voltage fluctuation becomes a fluctuation in the display luminance (transmittance of liquid crystal) of each pixel, which is observed as flicker
In addition, it may also cause a decrease in display quality such as insufficient contrast.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

no. 1 Embodiment approach

[0113] In the first embodiment, circuit configurations of a display device of the present invention (hereinafter referred to as a display device) and a pixel circuit of the present invention (hereinafter referred to as a pixel circuit) will be described.

[0114] figure 1 A schematic configuration of the display device 1 is shown. The display device 1 includes an active matrix substrate 10 , counter electrodes 80 , a display control circuit 11 , a counter electrode drive circuit 12 , a source driver 13 , a gate driver 14 , and various signal lines described later. On the active matrix substrate 10, a plurality of pixel circuits 2 are respectively arranged in the row direction and the column direction to form a pixel circuit array. In addition, in figure 1 In , the pixel circuit 2 is displayed in blocks in order to avoid the complexity of the drawings. In addition, in figure 1 In , in order to clearly show that various signal lines are formed on the active matrix substra...

no. 2 Embodiment approach

[0146] In the second embodiment, description will be made by type with reference to drawings Figure 5 ~ Figure 8 , Figure 11 and Figure 12 The illustrated self-polarity inversion operation of the pixel circuits 2A to 2F constituted by circuits of the first type to the sixth type is shown. In addition, the self-polarity inversion operation refers to an operation in which the first switch circuit 22, the second switch circuit 23, and the control circuit 24 are operated in a predetermined order for a plurality of pixel circuits 2 by the operation in the constant display mode. The polarity of the liquid crystal voltage Vlc applied between the pixel electrode 20 and the counter electrode 80 is also reversed while maintaining its absolute value. Therefore, all gate lines GL, source lines SL, selection lines SEL, reference lines REF, storage capacitor lines CSL, voltage supply lines VSL, and counter electrodes connected to the pixel circuit 2 to be subjected to the self-polarity...

no. 3 Embodiment approach

[0197] In the third embodiment, description will be made by type with reference to the drawings Figure 5 ~ Figure 8 , Figure 11 and Figure 12 The write operation in the constant display mode is performed by the pixel circuits 2A to 2F of circuit configurations of the illustrated first to sixth types.

[0198] The writing operation in the constant display mode is an operation in which the pixel data for one frame is divided into each display line in the horizontal direction (row direction), and the source lines SL of each column are written in each horizontal period. A binary voltage (high level (5V) or low level (0V)) corresponding to each pixel data of one display line is applied, and selection is applied to the gate line GL of the selected display line (selection row). A row voltage of 8V turns on the first switch circuits 22 of all the pixel circuits 2 in the selected row, and transfers the voltage of the source line SL of each column to the internal node N1 of each pi...

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PUM

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Abstract

Disclosed is a display device which achieves low power consumption without causing deterioration of an aperture ratio. A pixel circuit (2) is provided with: an internal node (N1) which holds a pixel data voltage applied to a display element section (21); a first switch circuit (22) which transfers, to the internal node (N1), a pixel data voltage supplied from a data signal line (SL) via at least a switch element (T4); a second switch circuit (23) which transfers, to the internal node (N1) not via the switch element (T4), a voltage supplied to a predetermined voltage supply line (VSL); and a control circuit (24) which holds, on one end of a first capacitive element (C1), a predetermined voltage that corresponds to the pixel data voltage held by means of the internal node (N1), and controls conduction / non-conduction of the second switch circuit (23).

Description

technical field [0001] The present invention relates to a pixel circuit and a display device including the pixel circuit, and particularly to an active matrix liquid crystal display device. Background technique [0002] In portable terminals such as mobile phones and portable game machines, a liquid crystal display device is generally used as a display unit thereof. In addition, since mobile phones and the like are driven by batteries, reduction in power consumption is strongly demanded. Therefore, the contents that need to be displayed constantly (time, remaining battery level, etc.) are displayed on the reflective sub-panel. In addition, recently, it has been demanded to use the same main panel for a normal display of a full-color display and a reflective type constant display. [0003] Figure 27 An equivalent circuit of a pixel circuit of a general active matrix liquid crystal display device is shown. in addition, Figure 28 A circuit configuration example of an acti...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G09G3/36G02F1/1368G09F9/30G09G3/20
CPCG09G2300/0852G09G3/3659
Inventor 山内祥光
Owner SHARP KK
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