Integrated Gray Voltage Generator for Display Devices
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Solution Overview
Problem
Vertical alignment mode liquid crystal displays (VA LCDs) face challenges with inferior side visibility due to uniform luminance across high gray levels, leading to a crumbled image appearance, and the existing gray voltage generators are costly and occupy significant space on printed circuit boards (PCBs).
Innovation Solution
A driving apparatus for display devices featuring a gray voltage generator integrated into a single chip, utilizing registers, multiplexers, digital-analog converters, and operational amplifiers to generate distinct gray reference voltages for sub-pixels, reducing the overall size and cost while improving side visibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a gray voltage generator is composed of separate parts (resistor column, switching elements, operational amplifiers mounted on PCB), then the display device can generate gray reference voltages, but the gray voltage generator occupies a large area on the PCB and is expensive
Solution Approach 1:
The patent merges the resistor column, switching elements, operational amplifiers, and other components of the gray voltage generator into a single integrated circuit chip. This integration eliminates the need for separate PCB mounting of individual components, thereby reducing the area occupied on the PCB and lowering manufacturing costs through consolidated production.
Solution Approach 2:
The integrated gray voltage generator chip performs multiple functions including voltage generation, signal processing, and control operations that were previously distributed across separate components. This multi-functional integration further reduces the overall system complexity and component count, contributing to both area reduction and cost reduction.
2Adaptability or versatility
If cutouts and protrusions are formed on field generating electrodes to disperse liquid crystal molecule inclination directions, then the reference viewing angle is increased, but side visibility deteriorates with uniform luminance across high gray levels
Solution Approach 1:
The patent applies different voltage levels to different sub-pixels within the same pixel through the integrated gray voltage generator. By generating distinct gray reference voltages for each sub-pixel, the system creates local variations in luminance that compensate for the uniformity issue caused by cutout structures, thereby improving side visibility while maintaining the wide viewing angle benefit.
Solution Approach 2:
The patent changes the voltage parameter applied to each sub-pixel to differentiate their luminance output. The integrated gray voltage generator produces multiple gray reference voltages with different levels, which are applied to different sub-pixels to create intentional luminance variations that improve side viewing characteristics without sacrificing the wide viewing angle advantage.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enhances side visibility by generating differentiated voltages for sub-pixels, reducing the size and cost of the gray voltage generator, and optimizing the display's performance by integrating key components into a compact, cost-effective integrated circuit.
Implementation Method 1
a converter including a plurality of digital-analog converters that are connected to the multiplexers
Implementation Method 2
a gray voltage generator formed of an integrated circuit to receive the digital data from the controller and to generate gray reference voltage sets
Data Source
AI summary
A driving apparatus for a display device includes a plurality of pixels arranged in a matrix, and each pixel includes first and second sub-pixels. The driving apparatus includes a memory for storing digital data, a controller for calling the digital data to output the digital data together with a clock signal and at least one selection signal, and a gray voltage generator formed of an integrated circuit to receive the digital data from the controller and to generate gray reference voltage sets. The gray voltage generator includes first and second registers for storing the digital data, a selector including a plurality of multiplexers for receiving the outputs of the first and second registers, and a converter including a plurality of digital-analog converters connected to the multiplexers. As described above, the gray voltage generator is provided in the form of a chip so that it is possible to reduce the area occupied on a printed circuit board (PCB) and to reduce the cost of the gray voltage generator.