Projection System Temporal Color Synthesis

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional projection devices have limitations in dynamic range and color synthesis, resulting in low output luminance and increased manufacturing costs due to the need for multiple sub-pixels and complex drive electronics.

Innovation Solution

A high dynamic range projection system is implemented using subsets of light patterns during temporal fields with two illuminants, allowing for color synthesis through temporal and spatial filtering, reducing the number of sub-pixels required and enhancing contrast ratio.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If three individually addressable sub-pixels (red, green, blue) are used to form full color pixels, then color output images can be produced in the RGB color space, but manufacturing costs increase due to additional components and drive electronics

Engineering Contradiction:
Improvecolor output capabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the blue sub-pixel from the traditional RGB trio, using only red and green sub-pixels. The blue color is synthesized temporally by displaying red and green sub-pixels in sequence rather than using a dedicated blue sub-pixel. This reduces the number of sub-pixels and associated drive electronics, directly addressing the manufacturing complexity issue while maintaining color output capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs temporal color synthesis by periodically displaying different combinations of red and green sub-pixels at different time intervals. By manipulating the timing and duration of red and green sub-pixel activation, the human visual system perceives synthesized colors including blue, cyan, yellow, and white. This periodic temporal modulation replaces the need for static blue sub-pixels, reducing device complexity while preserving color versatility.

Inventive Principle:
Principle #19Periodic action

2Adaptability or versatility

If three sub-pixels are used for each pixel, then full color images can be displayed, but the number of components and drive electronics increases, leading to higher manufacturing costs

Engineering Contradiction:
Improvecolor display capabilityVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent removes the blue sub-pixel component from the traditional RGB pixel structure, retaining only red and green sub-pixels. The blue color channel is generated through temporal synthesis rather than physical hardware. This extraction of unnecessary components directly reduces manufacturing costs while maintaining the ability to display full color images through temporal color synthesis.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using physical blue sub-pixels, the patent creates a temporal copy or representation of blue color by rapidly alternating red and green sub-pixel activation patterns. The human visual system integrates these temporal patterns to perceive blue color, effectively copying the visual effect of blue sub-pixels without the associated manufacturing complexity and cost.

Inventive Principle:
Principle #26Copying

3Adaptability or versatility

If conventional projection devices use three temporal fields with a single modulator, then color images can be synthesized, but the dynamic range of output luminance remains relatively low compared to analog film

Engineering Contradiction:
Improvecolor synthesis capabilityVSAvoidoutput luminance dynamic range
Core Design Contradiction:
Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent uses periodic temporal fields to display different combinations of red and green sub-pixels, synthesizing multiple colors including blue through temporal modulation. This periodic action enables color synthesis capability while allowing for enhanced luminance control through precise timing and intensity modulation of each sub-pixel activation cycle.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent changes the temporal parameters of sub-pixel activation, including duty cycle, pulse width, and timing intervals, to optimize both color synthesis and luminance output. By dynamically adjusting these temporal parameters, the system achieves high dynamic range luminance while maintaining accurate color synthesis, overcoming the limitations of conventional three-temporal-field approaches.

Inventive Principle:
Principle #35Parameter changes

4Difficulty of detecting and measuring

If red and green sub-pixels are kept in 'off' state during blue image display, then color accuracy is maintained, but luminance contribution from these sub-pixels is lost, reducing overall brightness

Engineering Contradiction:
Improvecolor accuracyVSAvoidoutput brightness
Core Design Contradiction:
Difficulty of detecting and measuringVSIllumination intensity

Solution Approach 1:

Instead of keeping red and green sub-pixels permanently off during blue display, the patent uses periodic temporal activation where these sub-pixels are briefly turned on and off in specific patterns. This periodic modulation allows the sub-pixels to contribute luminance during their active periods while still enabling blue color perception through temporal synthesis, thus improving overall brightness without sacrificing color accuracy.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent ensures continuous useful action by keeping red and green sub-pixels in a state of controlled temporal activation rather than complete idle state. Even when displaying blue-dominant images, these sub-pixels periodically contribute luminance through brief activation cycles, maintaining continuous light output and improving overall brightness while preserving color accuracy through precise temporal control.

Inventive Principle:
Principle #20Continuity of useful action

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 system achieves a high dynamic range with improved contrast ratio and reduced manufacturing costs by using fewer sub-pixels and simplifying the drive electronics, while minimizing artifacts and flicker.

Implementation Method 1

light from a light source onto an image modulator, which in turn, adjusts the intensity of incident light for each pixel

Methodology Applied
Scientific EffectLight modulation:

Implementation Method 2

Each color element can be configured to modify (e.g., by filtering) the color of the light patterns to produce the projectable image

Methodology Applied
Scientific EffectOptical filtering: Filter (optical)

Data Source

PatentEP2425630B1High dynamic range projection system, method to operate a high dynamic range projection system and computer readable medium
Publication Date: 2018.11.07 DOLBY LABORATORIES LICENSING CORP
  • EP2425630B1 patent drawingFigure 1
  • EP2425630B1 patent drawingFigure 2A
  • EP2425630B1 patent drawingFigure 2B

AI summary

Embodiments relate generally to computer-based image processing, and more particularly, to systems, computer-readable media, methods, integrated circuits, and apparatuses to facilitate operation of a projection system with relatively high dynamic range output by, among other things, providing subsets of light patterns along an optical path during respective first and second temporal fields associated with respective first and second illuminants. The projection system can synthesize color for projectable images by combining or otherwise using the subsets of light patterns with an array of color elements to produce projectable images with color in at least the visible spectrum.