Holographic Projection Distortion Mapping for Temperature Compensation
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Solution Overview
Problem
Holographic projectors experience distortion due to temperature and wavelength changes, leading to misalignment and reduced image quality, especially in multi-color reconstructions, which conventional methods address inefficiently through resource-intensive mapping and calibration.
Innovation Solution
A real-time method calculates a distortion map using a single pre-determined map and scaling vectors to compensate for temperature changes, allowing for efficient pre-distortion of target images to align multi-color reconstructions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple pre-determined distortion maps are stored for different temperatures and wavelengths, then image quality compensation is improved, but memory requirements and device complexity increase
Solution Approach 1:
The patent changes the approach from storing multiple complete distortion maps to storing a single reference map and calculating scaling factors based on temperature and wavelength parameters. The distortion compensation is achieved by dynamically adjusting the reference map using calculated scaling factors rather than selecting from pre-stored maps, thereby reducing memory requirements while maintaining compensation accuracy.
Solution Approach 2:
Instead of storing multiple complete distortion maps for different conditions, the patent creates a reference distortion map at a standard condition and generates other distortion maps by scaling and adjusting this reference map. This copying approach with parameter-based adjustment significantly reduces the memory burden of storing numerous complete maps.
2Measurement precision
If multiple pre-determined distortion maps are stored for different temperatures and wavelengths, then distortion compensation accuracy is improved, but computational burden increases
Solution Approach 1:
The patent extracts the essential temperature and wavelength dependency from the complete distortion maps by identifying and storing only the key scaling factors that represent these dependencies. Instead of processing complete maps for each condition, the system extracts and applies only the necessary scaling parameters to the reference map, reducing computational burden while maintaining accuracy.
Solution Approach 2:
The patent performs preliminary characterization to determine the scaling factors between different temperatures and wavelengths in advance. These scaling factors are stored for quick retrieval and application, eliminating the need for complex real-time calculations when distortion compensation is needed, thus improving computational efficiency.
3Manufacturing precision
If extensive characterization at multiple temperatures and wavelengths is performed, then distortion map accuracy is improved, but time and resource consumption increase
Solution Approach 1:
The patent makes a single reference distortion map serve multiple purposes across different temperatures and wavelengths by applying calculated scaling factors. This universal reference map approach eliminates the need for separate extensive characterization at each condition, as one well-characterized reference map can be adapted to various conditions through parameter scaling.
Solution Approach 2:
The patent performs the extensive and time-consuming characterization work once to create a high-accuracy reference distortion map at a standard condition. This preliminary action allows subsequent distortion compensations at different temperatures and wavelengths to be achieved through simpler scaling operations rather than repeating the full characterization process.
Data Source
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AI summary
There is provided a method of calculating a map in real-time, the map being for distorting a target picture to be projected by a holographic projector and to compensate for changes in the current temperature of the holographic projector. The method comprises receiving a calibrated map comprising a plurality of mappings. Each mapping is for transforming a respective two-dimensional coordinate of an array of two-dimensional coordinates to compensate for distortion at a predetermined temperature. Each two-dimensional coordinate corresponds to one or more image points of a target picture. The method further comprises receiving an array of vectors comprising a vector for each two-dimensional coordinate. Each vector represents a calibrated change of each respective two-dimensional coordinate over a predetermined temperature range. The method further comprises receiving a current temperature of the holographic projector. The method further comprises determining a scaling factor based on the difference between the current temperature and the predetermined temperature. The method further comprises calculating a modified map based on the current temperature by, for each coordinate of the array of two-dimensional coordinates: multiplying the vector that relates to the respective coordinate of the array of two-dimensional coordinates by the scaling factor to output a scaled vector; and applying the scaled vector to the respective mapping of the calibrated map. The method further comprises outputting the modified map.