Display Device Gray Scale Expansion via Metadata-Driven Voltage Control
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Solution Overview
Problem
Current display devices are unable to effectively display high dynamic range (HDR) image content due to their limited luminance dynamic range, which is narrower than the HDR image content they are intended to display, requiring image processing algorithms to convert HDR images to fit the display's capabilities and being limited by the number of bits in the digital image signal processed by the data driver.
Innovation Solution
A display device with a driving controller that analyzes metadata to expand the gray scale range by converting the first image signal into an expanded image signal, using a gamma correction circuit to adjust voltage levels and generate reference gamma voltages, allowing the data driver to produce gray scale voltages that extend beyond the conventional limitations, enabling the display of a wider luminance range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the number of bits of the digital image signal is increased to expand the gray scale range, then the luminance dynamic range is improved, but the device complexity and processing overhead increase
Solution Approach 1:
The patent changes the voltage level parameter of the driving voltage dynamically based on metadata luminance information. By adjusting the voltage level according to the minimum and maximum luminance values in the HDR content, the system expands the gray scale range without increasing the bit depth of the image signal, thus improving luminance dynamic range while avoiding increased device complexity
Solution Approach 2:
The patent introduces dynamic adjustment of driving voltage levels based on metadata analysis. The driving controller dynamically selects different voltage levels according to the luminance characteristics of each frame or scene, enabling the display device to adapt to HDR content requirements in real-time without requiring a fixed high-bit-depth signal path
2Adaptability or versatility
If image processing algorithms are used to convert HDR image content to fit the display device's luminance range, then the adaptability is improved, but the loss of information increases
Solution Approach 1:
The patent performs preliminary analysis of metadata containing luminance information before processing the image signal. By pre-determining the appropriate voltage level based on the minimum and maximum luminance values in the HDR content, the system prepares the optimal driving conditions in advance, enabling faithful reproduction of HDR luminance characteristics without information loss during conversion
Solution Approach 2:
The patent introduces metadata as an intermediary carrier that conveys luminance information from the HDR content to the driving controller. This intermediary enables the display device to understand the luminance characteristics of the content and adjust its driving voltage accordingly, facilitating accurate HDR display without direct lossy conversion of the image signal itself
Data Source
AI summary
A display device includes: a data driver for driving a plurality of data lines; a voltage generator for generating at least one driving voltage to be provided to the data driver; and a driving controller for providing a second image signal and a reference gamma selection signal to the data driver in response to a first image signal and a control signal received from the outside, wherein the driving controller outputs a voltage control signal for changing a voltage level of the at least one driving voltage, and the reference gamma selection signal, based on metadata included in the first image signal, and the data driver receives the reference gamma selection signal and the at least one driving voltage to provide, to the plurality of data lines, data voltage signals corresponding to the second image signal.