Temporal Cadence Perturbation for Stereoscopic Displays

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Solution Overview

Problem

Current stereoscopic display technologies using time-division multiplexing result in unwanted 'false depth' cues for objects moving along the axis of ocular separation due to fixed temporal separation of image streams, causing discomfort to viewers.

Innovation Solution

The method involves determining the screen space velocity of moving objects and modifying their perceived depth by alternating the precedence of left and right images in stereoscopic image pairs, using a table of depth offsets to adjust the display timing and reduce or eliminate false depth perception.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If time-division multiplexing is used to display stereoscopic images, then the display device can show multiple image streams, but false depth cues appear for objects moving along the axis of ocular separation

Engineering Contradiction:

Improvenumber of image streamsVSAvoidfalse depth cues

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by making the temporal precedence relationship between left and right image streams dynamic rather than fixed. The system alternates which stream precedes in successive display frames, adapting the display timing to compensate for object motion and eliminate false depth cues while maintaining the ability to display multiple image streams

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the temporal parameter of image stream presentation by alternating the precedence timing between left and right streams. This parameter change in display timing compensates for the temporal separation effect on moving objects, eliminating false depth perception while preserving multi-stream display capability

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If one image stream precedes the other by a fixed period, then the display timing is simple, but unwanted false depth cues are created for moving objects

Engineering Contradiction:

Improvedisplay timing complexityVSAvoidfalse depth cues

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The invention transitions from a static fixed-precedence timing scheme to a dynamic alternating precedence scheme. By switching which stream precedes in successive frames, the system compensates for temporal separation effects on moving objects without requiring complex per-object timing calculations, thus reducing false depth cues while maintaining manageable complexity

Inventive Principle:

Principle #15Dynamics

3Speed

If the frame rate is tripled to smooth projection, then motion rendition is improved, but the temporal separation between image streams remains fixed causing false depth

Engineering Contradiction:

Improveframe rateVSAvoidfalse depth cues

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by implementing alternating precedence of image streams within the high frame rate structure. This dynamic timing adjustment compensates for the fixed temporal separation that persists even at tripled frame rates, eliminating false depth cues while preserving the smooth motion rendition benefits of the high frame rate

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS9621870B2Temporal cadence perturbation for time-division stereoscopic displays

Publication Date: 2017.04.11 PIXAR CORP

AI summary

One or more techniques to reduce or eliminate the false depth of objects that move along the axis of ocular separation when displayed using time division multiplexing. Experiments can be performed to determine a perceived depth of an object moving with known velocity. Then, when rendering stereoscopic image pairs, the location of the object can be modified to change the perceived stereoscopic depth of the object to compensate for the false depth. In one technique, the images can be displayed with alternating left- and right-precedence to reduce the perception of false depth.