Compensation circuit for a liquid crystal display

Abstract

A compensation circuit is provided to remove the flicker occurring on the panel of a liquid crystal display by adjusting the data signal applied to each pixel. The compensation circuit mainly includes: a memory device, a buffer, a digital/analog converter and a data signal line driving circuit. The memory device stores a plurality of digital compensation data wherein each is used as the compensation signal for a pixel of the LCD. The buffer is connected to the memory device for temporarily storing the compensation data coming from the memory device in response to a first clock. The digital/analog converter is connected to the buffer for converting the digital data coming from the buffer into an analog data in response to a second clock. The data signal line driving circuit consists of n (the number of pixels on each scan line) units each is composed of a sample/hold circuit unit and an output circuit unit. Each sample/hold circuit unit receives an analog data coming from the digital/analog converter or a ground potential, samples the received data and holds the sampled result. Each output circuit unit receives the output data coming from the corresponding sample/hold circuit unit and an external signal, outputs the summed result of the two received data to a corresponding pixel. When flicker compensation is to be performed, each sample/hold circuit unit receives an analog compensation data coming from the digital/analog converter. On the other hand, when flicker compensation is not to be performed, each sample/hold circuit unit receives a ground potential.