Projector Sensor Using Diffracted Light for Calibration
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Solution Overview
Problem
Existing image display apparatuses, such as projectors, face challenges in performing calibration with high accuracy and simplicity, particularly in correcting white balance and gamma, due to complex structures and reduced precision in measuring light intensity.
Innovation Solution
An image display apparatus comprising a light source unit, at least one light modulation device, and a sensor that measures diffracted light intensity, allowing for accurate calibration by arranging the sensor on the light path of diffracted light with a predetermined order and using a periodic structure formed by two-dimensionally arranged pixels to generate diffracted light, enabling precise measurement without obstructing the projector's image projection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sensor is placed to directly measure light intensity from the light modulation device, then measurement precision is improved, but the projector optical system becomes more complex and image projection may be obstructed
Solution Approach 1:
The patent extracts the measurement function from the main optical path by utilizing diffracted light that exits the projector at specific angles. The sensor receives only the diffracted light components (higher-order diffraction) that do not enter the projector optical system, separating the measurement function from the projection function and avoiding obstruction of the image projection path.
Solution Approach 2:
The patent introduces diffracted light as an intermediary carrier for measurement. Instead of directly measuring the main light beam, the system uses the diffracted light components generated by the periodic structure of the light modulation device as an intermediate signal that carries the necessary intensity information without interfering with the primary projection function.
2Measurement precision
If the sensor receives diffracted light from the periodic structure of pixels, then measurement precision is improved, but the structure becomes more complex
Solution Approach 1:
The patent applies the self-service principle by utilizing the inherent periodic structure of the light modulation device pixels themselves as the diffraction grating. The system uses the existing pixel arrangement to generate diffracted light for measurement purposes, eliminating the need for separate diffraction gratings or additional structural elements, thus improving measurement precision without adding device complexity.
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 solution enables calibration with a simple structure and high accuracy, allowing for precise measurement of modulated light intensity and correction of white balance and gamma, thereby producing images with improved quality.
Implementation Method 1
the at least one light modulation device includes a plurality of two-dimensionally arranged pixels, the plurality of two-dimensionally arranged pixels forming a periodic structure, the periodic structure being configured to generate the diffracted light
Implementation Method 2
The sensor is configured to receive diffracted light of the modulated light beam emitted from the at least one light modulation device, and to measure intensity of the modulated light
Data Source
AI summary
There is provided an image display apparatus including: a light source unit; at least one light modulation device configured to modulate light from the light source unit, and to emit a modulated light beam; and a sensor configured to receive diffracted light of the modulated light beam emitted from the at least one light modulation device, and to measure intensity of the modulated light.