OR-function illumination for phased bitplane flicker reduction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Phased switching of bitplanes in high dynamic range projectors introduces artifacts at pixel group boundaries due to incorrect illumination of prime DMD pixels caused by the point spread function, leading to noticeable flicker and halo effects.

Innovation Solution

Implementing an OR-function illumination scheme in the premod display, where adjacent pixel groups are driven according to a phased sequence using blurred or unblurred versions of leading and following bitplanes, ensuring all prime display pixels are correctly illuminated by using an OR-function of premod versions of respective bitplanes, and optionally employing global or phased bitplane switching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If phased switching of bitplanes is used to reduce black levels and increase contrast, then image quality is improved, but artifacts appear at pixel group boundaries due to incorrect illumination

Engineering Contradiction:

Improveblack levels and contrastVSAvoidflicker artifacts at pixel group boundaries

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The premod display is driven in advance with an OR-function of multiple bitplanes before the prime display switches to the following bitplane. This preliminary illumination ensures that pixels near group boundaries are correctly illuminated during the transition, preventing flicker artifacts while maintaining the contrast benefits of phased switching.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Multiple bitplanes are combined using an OR-function to create a composite illumination pattern for the premod display. This merging of bitplane data ensures continuous correct illumination across pixel group boundaries during phased transitions, eliminating flicker while preserving the high contrast advantage.

Inventive Principle:

Principle #5Merging (Combining)

2Loss of time

If phased switching is used to update only a portion of the DMD, then loading time is reduced, but illumination correctness is compromised at boundaries

Engineering Contradiction:

Improveimage data loading timeVSAvoidillumination correctness at pixel group boundaries

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The premod display is updated in advance with the OR-function composite before the prime display completes its phased transition. This preliminary action ensures illumination reliability is maintained during the time-efficient phased loading process, as the premod display already contains the correct composite pattern when needed.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The premod display acts as an intermediary between the image data loading process and the final prime display output. By processing and displaying the OR-function composite in advance, it mediates the transition smoothly, ensuring illumination correctness without requiring the entire prime display to be reloaded.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If the premod display uses OR-function illumination of multiple bitplanes, then all prime display pixels are correctly illuminated, but halos may be introduced as a trade-off

Engineering Contradiction:

Improvecorrect illumination of all prime display pixelsVSAvoidhalo effects

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The OR-function illumination is applied periodically only during the specific time periods when the prime display is transitioning between bitplanes. By limiting the OR-function application to these periodic transition intervals rather than continuous operation, the halo effect is minimized while maintaining correct illumination reliability during critical transition moments.

Inventive Principle:

Principle #19Periodic 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

This approach reduces and eliminates flicker artifacts at pixel group boundaries, ensuring consistent illumination of prime display pixels, although it may introduce halos as a trade-off, effectively improving image quality by maintaining proper illumination of 'on' pixels.

Implementation Method 1

a premod display and a prime display, the premod display configured to modulate light from the light source to illuminate the prime display

Methodology Applied

Scientific EffectLight modulation:

Implementation Method 2

by the PSF (point spread function) spreading the image from premod DMD pixel groups configured for two different bitplanes across prime DMD pixels configured for a single bitplane

Methodology Applied

Scientific EffectPoint spread function: Diffraction

Data Source

PatentUS10070105B2OR-function illumination in phased bitplanes in a high dynamic range projector

Publication Date: 2018.09.04 CHRISTIE DIGITAL SYSTEMS USA INC

AI summary

OR-function illumination in phased bitplanes in a high dynamic range projector is provided, which can be used to reduce flicker artifacts. The projector comprises: a light source; a premod display; a prime display, the premod display configured to modulate light from the light source to illuminate the prime display; and, a computing device. The computing device drives the prime display according to a phased sequence to transition the prime display from a leading bitplane to a following bitplane. The computing device is further configured to, at least in a time period corresponding to the prime display being driven according to the phased sequence, drive adjacent pixel groups of the premod display according to an OR-function of premod versions of respective portions of each of at least the leading bitplane and the following bitplane.