Sequential Color Display Drive with Spatial-Temporal Alternation

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Solution Overview

Problem

Sequential drive schemes in displays, such as active matrix liquid crystal displays, face challenges in maintaining resolution while minimizing color break-up and improving efficiency, particularly in autostereoscopic modes where high motion can cause distracting color visibility issues.

Innovation Solution

Implementing a method with two cycles of color properties where each cycle uses at least two different colors, alternating spatially and temporally, ensuring all pixels are illuminated, and using a patterned backlight or discrete light sources to provide different colors to pixels, which reconstructs the total resolution and reduces color break-up.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a sequential drive scheme is used to increase resolution, then the number of sub-pixels per pixel is reduced, but color break-up occurs during high motion

Engineering Contradiction:
ImproveresolutionVSAvoidcolor break-up
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The display is divided into multiple zones along the column direction, with each zone containing pixels that are driven with the same color sequence. This segmentation allows the color breakup to be localized to specific zones rather than affecting the entire display, making the artifact less noticeable and manageable.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different color sequences are applied to different zones of the display based on local requirements. Each zone can have optimized color sequencing independent of other zones, allowing tailored solutions for different regions of the display to minimize color breakup in high-motion areas.

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If three separate dots (sub-pixels) are used per pixel with color filters, then color output is achieved, but the aperture for transmitted light is reduced resulting in low brightness

Engineering Contradiction:
ImprovebrightnessVSAvoidaperture ratio
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The backlight is flashed periodically with the three color primaries in sequence within one image buildup period. This periodic illumination allows each primary color to be transmitted through a larger aperture area at different times, increasing overall brightness while maintaining color output through temporal multiplexing.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent transitions from spatial color separation (three simultaneous sub-pixels) to temporal color separation (sequential backlight flashing). By adding the time dimension to color delivery, each pixel location can have a larger aperture while still achieving full color through sequential illumination of the three primaries.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Manufacturing precision

If the backlight is flashed quickly to create color sequential display, then resolution is increased, but the eye may perceive color break-up during high motion

Engineering Contradiction:
ImproveresolutionVSAvoidcolor break-up visibility
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent implements dynamic control of color sequencing where different zones can use different color sequences that are adapted to local motion characteristics. This dynamic adaptation allows the system to optimize for resolution while minimizing color breakup visibility by adjusting color delivery strategies based on local display conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of color sequence assignment from a uniform global sequence to zone-specific sequences. By varying the color sequence parameter across different zones, the system can maintain high resolution through sequential driving while reducing the visibility of color breakup artifacts through localized optimization.

Inventive Principle:
Principle #35Parameter changes

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

This approach increases resolution by 150% and reduces color break-up, providing a more stable image quality during high motion, and is particularly beneficial for autostereoscopic displays by enhancing 3D resolution and depth perception.

Implementation Method 1

The liquid crystal pixel can then sequentially control the amount of each primary color transmitted

Methodology Applied
Scientific EffectLiquid crystal light modulation: Liquid Crystals

Implementation Method 2

the lenticular elements are typically provided as a sheet of lenticular elements (lenticulars), each of which comprises an elongate lens element

Methodology Applied
Scientific EffectLight refraction: Refraction

Data Source

PatentEP2409294B1Methods of driving colour sequential displays
Publication Date: 2020.05.06 KONINKLIJKE PHILIPS NV
  • EP2409294B1 patent drawingFigure 1A~1C
  • EP2409294B1 patent drawingFigure 2
  • EP2409294B1 patent drawingFigure 3

AI summary

A method of driving a display uses first (4) and second (5) illumination cycles of the display. In each cycle, a first set of pixels (1') is illuminated with a first color (R, G) and a second set of pixels (2') is illuminated with a second color (G, B). The first and second colors of the two cycles together include at least three colors (R, G, B) for forming an image. This method provides a sequential drive scheme, in that at least two cycles are used with different color properties. However, each cycle uses at least two different colors, so that each cycle is not a single color across the whole display area. In this way, the color sequence is alternated spatially as well as temporally.