Adaptive compensation power-supply apparatus and its drive method

Abstract

The invention relates to an adaptive compensation power device and the driving method, the device comprises two circuit reference powers, an attenuation detecting unit, a difference comparing unit, wherein the attenuation detecting unit is electrically connected and the digital direct current reference power is accepted. A voltage difference and a difference compensation unit are obtained after contrasting the voltages of the analogous circuit reference power and the digital direct current reference power. The invention utilizes a detecting circuit to detect the drift amount of the analogous circuit reference power to the reference position in an analogous source drive, and provides an compensation potential, and outputs a stable direct current voltage as the analogous circuit reference power after compensation to balance the output reference position differences of the every analogous source drives, further eliminates the block defects between the adjacent intervals of a panel.

Description

technical field [0001] The invention relates to a power supply compensation device, in particular to an adaptive compensation power supply device applied to a display. Background technique [0002] see figure 1 , is a schematic diagram of a bias circuit of a thin film transistor liquid crystal display in the prior art. Generally, the driver IC of a thin film transistor liquid crystal display is directly arranged on the glass, film or tape of the thin film transistor array, and multiple analog source drivers (source ICs, such as S1, S2, and S3 in the figure) are arranged on the On one side of the substrate, the analog gate driver (gateIC, G1 in the figure) is arranged on the other side of the substrate, and the signal connection lines between the drivers are directly laid out on the substrate, and connected with the flexible printed circuit board 2 (Flexible Print Circuit, FPC) connected to receive the signal sent by the external system. As shown in the figure, the referen...

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Problems solved by technology

However, since the bias power supply of the unity-gain operational amplifier 10 is AVDD, when AVDD is affected by layout traces, impedance effects of trace materials, and the internal impedance of the source IC itself, AVDD attenuates, causing each source IC to output different voltage levels. , then the unity-gain operational amplifier 10 will not be able to charge the pixel capacitor 12 with the most correct voltage, so that color block defects will occur on the panel display screen

Also, multiple switches in the display circuit of the single output end of the thin film transistor liquid crystal display utilize P-channel metal-oxide-semiconductor (PMOS) to achieve the action of the switch, yet there is a parasitic diode 14 in the PMOS itself (its conduction bias is 0.7 volts) across the drain terminal (D) and base terminal (B) of the PMOS, if the voltage difference between the input data voltage (data) and AVDD is greater than the conduction bias of the parasitic diode 14 due to the attenuation of AVDD If the voltage is 0.7 volts, the parasitic diode 14 will be turned on, causing the leakage of the voltage originally existing in the capacitor of the energy storage element in the display circuit, thereby causing the output level of each source IC to be different.

[0004] To sum up the above, since AVDD is a pulsating DC signal, the ripple of the signal is very large, and the addition and multiplication of the AVDD voltage difference between each source IC will cause the sample and hold circuit (sample and hold) of each source IC internal circuit circuit) and the AVDD of the output operational amplifier are different, and the output voltages of each other are different. The difference in the output voltage of the source IC will directly affect the quality performance of the screen, making the brightness of the display screen inconsistent, so that the color of adjacent areas in the panel appears. Blocks (such as block 4, block 6, and block 8 shown in Figure 1, usually the color of block 4 will be darker than block 6, and the color of block 6 will be darker than block 8 deep) phenomenon

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