Active Defocus Display Assembly for Focus Stability and Brightness
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Solution Overview
Problem
Optical lenses in display systems are prone to performance variance due to temperature changes, manufacturing tolerances, and alignment issues, affecting focus and brightness, especially in faster lenses with smaller depth of field.
Innovation Solution
Implementing an active defocus mechanism that adjusts focusing lenses in response to multiple defocus factors, including content-based and dual-photodiode defocus factors, using actuators and sensors to refine focus based on captured images and thermal readings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If faster lenses with smaller F-stop are used to increase brightness, then illumination intensity is improved, but depth of field decreases making the system more sensitive to focal length changes
Solution Approach 1:
The patent implements a dynamic focus adjustment system that actively compensates for focal length changes. A movable lens element is positioned by an actuator based on feedback from a disparity image sensor, allowing the system to adaptively maintain focus stability despite using faster lenses with inherently smaller depth of field.
Solution Approach 2:
The system uses a disparity image sensor to continuously monitor focus conditions and generate feedback signals. This feedback drives the actuator to adjust the lens position, creating a closed-loop control system that maintains optimal focus while enabling the use of brighter, faster lenses.
2Reliability
If manual focus adjustment is used to compensate for temperature and manufacturing variations, then focus stability can be improved, but device complexity and ease of operation deteriorate
Solution Approach 1:
The system performs self-adjustment through an automated feedback loop. The disparity image sensor automatically detects focus errors caused by temperature changes or manufacturing tolerances, and the actuator automatically compensates without user intervention, eliminating the need for manual focus adjustment while maintaining focus stability.
Solution Approach 2:
A closed-loop feedback system continuously monitors image sharpness using the disparity image sensor and automatically adjusts lens position accordingly. This eliminates manual adjustment mechanisms while maintaining focus stability across varying environmental and manufacturing conditions.
3Measurement precision
If manual focus adjustment is required to maintain image sharpness, then image clarity can be improved, but ease of operation deteriorates
Solution Approach 1:
The system automatically maintains image sharpness through self-adjustment. The disparity image sensor continuously evaluates image quality and triggers automatic lens repositioning when degradation is detected, eliminating the need for user intervention while preserving image clarity.
Solution Approach 2:
The system employs real-time feedback from the disparity image sensor to detect image sharpness variations and automatically adjusts focus accordingly. This closed-loop control maintains optimal image clarity without requiring manual user operation.
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
Enhances focus stability and brightness by dynamically adjusting lenses to compensate for temperature and manufacturing variations, improving image clarity and reducing sensitivity to focal length shifts.
Implementation Method 1
The focus of an optical lens may change with temperature
Implementation Method 2
a dual-photodiode defocus factor may be generated in response to an alignment of a first intensity profile of the adjustment image and a second intensity profile of the adjustment image that is captured by the dual-photodiode disparity image sensor
Data Source
AI summary
An adjustment image of a projected image is captured by a disparity image sensor. A first defocus factor in generated response to comparing the adjustment image with a reference image driven onto a display projector assembly the generated the projected image. A second defocus factor is generated in response to an alignment of a first intensity profile of the adjustment image and a second intensity profile of the adjustment image. A focusing lens of the display projector assembly is adjusted in response to at least one of the first defocus factor and the second defocus factor.