Dual-Panel HDR Display Codeword Optimization

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Solution Overview

Problem

High Dynamic Range (HDR) displays face challenges in reproducing starfields and other challenging images due to parallax, backlight leakage, and artifacts such as moiré patterns, which existing technologies fail to adequately address.

Innovation Solution

A dual-panel display system is implemented, comprising a control module that selects codeword pairs to drive an image-generating panel and a contrast-improving panel, optimizing image rendering by minimizing parallax, contouring, and Just Noticeable Difference (JND) steps, while preserving peak luminance and improving contrast and resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If local dimming of the backlight is used to achieve high contrast ratios, then the contrast ratio is improved, but parallax and backlight leakage artifacts occur

Engineering Contradiction:

Improvecontrast ratioVSAvoidparallax and backlight leakage

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The display system is divided into two separate panels: a first image-generating panel and a second contrast-improving panel. This segmentation allows each panel to perform its specialized function independently, with the first panel generating the image and the second panel specifically addressing contrast enhancement without the harmful side effects of traditional local dimming approaches

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The second contrast-improving panel acts as an intermediary between the backlight and the first image-generating panel. By placing this intermediate panel in the optical path, the system can control light transmission more precisely, reducing backlight leakage and parallax effects while maintaining high contrast ratios

Inventive Principle:

Principle #24Intermediary (Mediator)

2Illumination intensity

If multiple registered modulating layers or premodulators are used to improve contrast, then the contrast is improved, but device complexity increases

Engineering Contradiction:

ImprovecontrastVSAvoidnumber of modulating layers

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The patent combines the image generation function and the contrast improvement function into a single integrated dual-panel system. Rather than adding separate modulating layers to an existing display, the invention merges these functions into two coordinated panels that work together as one unified display device

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The second contrast-improving panel serves multiple functions simultaneously: it improves contrast, reduces parallax, and minimizes backlight leakage. This multi-functionality in a single panel component reduces the need for additional separate components that would increase device complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Illumination intensity

If codeword pairs are selected to preserve peak luminance, then peak brightness is maintained, but image rendering quality may be compromised

Engineering Contradiction:

Improvepeak luminanceVSAvoidimage rendering quality

Core Design Contradiction:

Illumination intensityVSManufacturing precision

Solution Approach 1:

The control module uses feedback from the input image data characteristics (such as peak luminance requirements) to dynamically select optimal codeword pairs for driving the dual-panel system. This feedback mechanism ensures that the selected codewords simultaneously maintain peak luminance and minimize rendering artifacts by considering the specific requirements of each image being displayed

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically changes the codeword parameters based on the input image characteristics. By adjusting the codeword selection according to the specific image being displayed (particularly considering peak luminance requirements), the system optimizes both brightness maintenance and image rendering quality for each display scenario

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9135864B2Systems and methods for accurately representing high contrast imagery on high dynamic range display systems

Publication Date: 2015.09.15 DOLBY LABORATORIES LICENSING CORP

AI summary

A dual-panel display system is provided that comprises control modules and algorithms to select codeword pairs (CWs) to drive a first image-generating panel and a second contrast-improving panel. The first codewords is selected by considering some characteristics of the input image data (e.g., peak luminance) and to improve some image rendering metric (e.g., reduced parallax, reduced contouring, improved level precision). The first codeword may be selected to be the minimum first codeword within a set of codeword pairs that preserves the peak luminance required by the input image data. Also, the first codeword may be selected to minimize the number of Just Noticeable Difference (JND) steps in the final image to be rendered. The second codeword may be selected to similarly improve image quality according to a given quality metric.