Retinal Image Projection With Eye-Tracking Beam Compensation

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Solution Overview

Problem

Conventional image projection systems onto the retina face challenges in accurately compensating for eye movements and positional changes, leading to instability of projected images on the retina due to gaze direction and relative position variations.

Innovation Solution

An image projection system with an optical assembly and sensor assembly that adjusts the lateral and angular orientation of the light beam in real-time using actuation signals to compensate for eye movements and positional changes, utilizing a controller to process data from sensors to generate actuation signals for precise image projection on the retina.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional image projection systems project images to an intermediate image plane in front of the eye, then the image can be focused onto the retina when the eye lens focuses to that distance, but the image becomes unstable when the eye moves or changes gaze direction

Engineering Contradiction:
Improveimage stability on retinaVSAvoidoptical relay system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the intermediate image plane from the optical path entirely, projecting images directly onto the retina without requiring an intermediate projection surface. This extraction of the intermediate plane simplifies the optical relay system while maintaining image stability through direct retinal projection and eye movement compensation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system employs eye tracking sensors to detect eye position and gaze direction, feeding this information back to the image projection system. The feedback mechanism enables real-time adjustment of the projected image position and orientation, compensating for eye movements and maintaining stable retinal imaging despite changes in gaze direction.

Inventive Principle:
Principle #23Feedback

2Reliability

If the intermediate image plane is placed at a certain finite distance in front of the eye, then the projection system can focus the image onto the retina, but the system cannot compensate for variations in relative lateral position between the projection system and the eye

Engineering Contradiction:
Improveimage projection accuracyVSAvoidcompensation for positional variations
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic adjustment mechanisms that allow the image projection system to adapt in real-time to variations in relative lateral position between the projector and the eye. The system dynamically modifies the projection parameters based on detected positional changes, enabling compensation for movement while maintaining accurate image projection on the retina.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes projection parameters such as image position, orientation, and focus in response to detected eye position and gaze direction variations. By dynamically adjusting these parameters, the system compensates for relative lateral position changes and maintains reliable image projection accuracy despite movement.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If the eye moves or changes gaze direction, then the relative position between the eye and projection system varies, but conventional systems cannot compensate for these large movements

Engineering Contradiction:
Improvecompensation for eye movementsVSAvoidimage projection precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system uses eye tracking sensors to continuously monitor eye position and gaze direction, providing feedback signals that enable real-time compensation for large eye movements. This feedback mechanism allows the projection system to adapt to movement while maintaining precise image projection on the retina.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary eye tracking and prediction to anticipate eye movements before they affect image stability. By detecting eye position trends and predicting future positions, the system can pre-adjust the projection parameters, maintaining image precision even during large eye movements.

Inventive Principle:
Principle #10Preliminary 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 ensures stable image projection on the retina by compensating for large eye movements and positional changes, maintaining image stability despite gaze direction and relative position variations.

Implementation Method 1

an optical assembly configured to direct the ILB to propagate along a propagation path towards the eye

Methodology Applied
Scientific EffectLight propagation: Light

Implementation Method 2

obtain data indicative of the lateral and angular deviations between the ILB and the eye

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP4657137A1Image projection system and method of operating thereof
Publication Date: 2025.12.03 VOXELSENSORS SRL
  • EP4657137A1 patent drawingFigure 1
  • EP4657137A1 patent drawingFigure 2
  • EP4657137A1 patent drawingFigure 3

AI summary

The present invention relates to an image projecting system comprising: an image projecting module configured to provide an image light beam (ILB) projecting image frames to an eye image plane; a sensor assembly configured to provide data indicative of lateral and angular deviations between orientations of the ILB and the eye; an optical assembly configured to direct the ILB to propagate along a propagation path towards the eye, wherein the optical assembly is configured to adjust, in response to actuation signals, an angular orientation and a lateral position of the ILB; and a controller operatively connected to the sensor assembly and to the optical assembly, the controller configured to process the data received from the sensor assembly to generate actuation signals and to send to the optical assembly first actuation signals configured to compensate lateral deviations between the ILB and a lateral position of a pupil of the eye and second actuation signals configured to compensate angular deviations between orientation of the ILB and a gaze direction of the eye, wherein the controller is configured to send the first actuation signals multiple times during each frame and to send the second actuation signals at the beginning of each frame, and wherein each second actuation signal is generated based on a prediction of an angular eye position at the beginning of a respective frame.