Display Driver Buffer Amplifier for Uniform Voltage Deviation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional display drivers generate driving voltages with significant dispersion in deviations, leading to decreased display quality and gradation representation performance due to varying offset characteristics among buffers, resulting in different deviation polarities and sizes even for the same gradation voltage.
Innovation Solution
A method and buffer amplifier that standardize deviation polarities to either positive or negative, reducing the dispersion range of deviations by approximately half by setting buffers to specific types based on test gradation voltage logic levels and using chopping signals to adjust input and output terminals, ensuring all driving voltages have consistent deviations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional buffers are used without standardization, then each buffer operates independently with its own offset characteristics, but the dispersion range of deviations increases and display quality decreases
Solution Approach 1:
The patent applies preliminary action by performing a test operation before normal buffering to determine each buffer's offset characteristic. During this test phase, a test gradation voltage is input and the logic level of the output is latched to identify whether the buffer has positive or negative deviation. This preliminary classification enables subsequent standardization without adding complexity to the normal buffering operation.
Solution Approach 2:
The patent implements local quality by configuring each buffer individually based on its specific offset characteristic. Buffers are divided into two types (first type with positive deviation, second type with negative deviation) and each type is connected to different input terminals (first input terminal or second input terminal) of the buffer. This localized customization ensures that each buffer operates in its optimal configuration, reducing overall deviation dispersion while maintaining simple individual buffer structures.
2Measurement precision
If buffers with different offset characteristics are used, then more buffer types can handle various gradation voltages, but the deviation polarities and sizes vary leading to decreased gradation representation performance
Solution Approach 1:
The patent applies parameter changes by modifying the operational parameters of buffers based on their measured offset characteristics. Specifically, the input terminal assignment (first or second input terminal) and chopping signal phase (in-phase or anti-phase) are changed according to whether the buffer has positive or negative deviation. This parameter adjustment standardizes the output deviation polarity across all buffers, improving gradation representation accuracy while preserving the adaptability of different buffer types.
3Reliability
If no test operation is performed, then the buffer operation is simpler and faster, but the deviation dispersion range cannot be reduced and display quality suffers
Solution Approach 1:
The patent performs the test operation as a preliminary action during the initialization phase or factory calibration, before the display device enters normal operation. The latched logic levels from the test operation are stored and used to automatically configure the buffers during normal operation. This approach incurs a one-time time cost during initialization but ensures high driving voltage accuracy throughout the device's operational lifetime without recurring time penalties.
Data Source
AI summary
A method of generating a driving voltage includes inputting a test gradation voltage to a first input terminal and a second input terminal of a buffer, latching the logic level of a test driving voltage output from an output terminal of the buffer, setting the buffer to a first type when the logic level of the test driving voltage is high level and setting the buffer to a second type when the logic level of the test driving voltage is low level, and operating the buffer set to the first type or the second type to generate a driving voltage corresponding to a gradation voltage.