LCD displays have two major development directions. One direction is LCD-TV with larger screen size, higher resolution, and better dynamic picture quality. The most important task is to improve the quality of moving images, that is, to solve the problem of natural motion artifacts in LCD displays. The other direction is that the display screens used for mobile display (such as mobile phone display screens) are developing towards higher speed and higher resolution. That is, the mobile display screen should display 1280800 or 1366768 pixel video signals and pictures, and the screen size It is also enlarged to 5 inches to 6 inches. To this end, a series of low-cost, low-power chips must be developed.
Maintained display and slower time response are the reasons why LCD produces motion artifacts. The CRT display is a transient display. The phosphor of each pixel is excited by the electron beam and emits light only in about 0.1ms in a frame, and the brightness of the image at that position is displayed, and then it decays to zero in about 1ms. It glows again in the next frame to show another position. The movement felt by the human eye is smooth, and the dark period is filtered out by the low-pass time response characteristic of the human eye (the so-called persistence of vision). TFT-LCD is a maintenance type. It displays any moving object. It always stays in one position within one frame and jumps to another position in the next frame. With the automatic tracking feature of the human eye on the moving object, it will The luminous intensity is integrated, and the human eye feels blurred to the moving image, which is the motion artifact. To solve the slow response time of LCD, overdrive (OD, Over Drive) technology can be used to reduce the response time of liquid crystal (LC) to 8ms or less. However, how to correctly select the size of the overdrive voltage is still a big technical problem. Excessive OD will cause bright and dark sides on the edge of the moving target, that is, edge artifacts in overdrive; insufficient OD will make the response time of LC not short enough and cause blurred moving images. Even if the response time of LC has been satisfactorily resolved, the characteristics of the LCD sustaining display will still produce a series of artifacts in the moving image. For high-resolution large displays, the problem of motion artifacts becomes serious. Therefore, a series of measures have been taken to reduce the maintenance time (ie, the integration time) to make the LCD display closer to the transient display, so as to reduce the generation of motion artifacts.
