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Abstract
英国留学生电子科技工业应用论文 Thoughtful distinction between programmability for prototyping and mass-production proposes “Master slice gamma correction”, which gives not only programmability to adapt individual company or panel-specific gamma correction characteristic, but also both low-cost and low-power driver IC.

1.Introduction
Programmability is a desirable function in general to adapt several gamma correction characteristics for multiple companies or for multiple panels by a single source driver. However it has many aspects according to its problem as explained below.
The first problem is an exploration of specification itself. Figure 1shows a typical configuration to perform “system design” on gamma correction. It is very problematic that it includes tentative source drivers to drive LCD panel to measure the ideal characteristic. The tentative source drivers are not tuned to the ideal, but somewhat good for driving. System engineer may expect that this tentative maybe replaced with the final one to be implemented because they need final test by using real pictures. For this case, full programmability is attractive for system designer to quest the final ideal characteristic.

The second problem is an assembling that Reference voltages are not well distributed to each source drivers via PCB, especially via COG, to panel.
The third problem is accuracy. The PWL (piece-wise linear) approximation of gamma correction characteristic is a popular solution for 6-bit accuracy such as mobile application. On the other hand, TV and PC application already have 8-bit accuracy and therefore they exploit a LUT (look-up table) to assure its accuracy. Mobile application is requested to get more accuracy by expecting mobile TV. The visual 6 bit means electrical 8 bit, so that PWL requires 8-bit accuracy in order to faithfully reproduce the desired characteristic. However it is impossible to implement faithful 8-bit accuracy by PWL: the lines cannot fit the curve accurately within whole range. This is because that the VTcharacteristic is experimentally approximated by the certain kind of exponential called TRC (Tone Reproduction Curve). As exponential is irrational, any attempt to use fix number of boundary points of PWL is not enough.

6. References
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