Projector Color Correction via RGB-to-XYZ Conversion
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Solution Overview
Problem
Existing projector technologies face challenges in accurately measuring and correcting image light colors, particularly due to variations in spectral sensitivity between measurement devices and human eye sensitivity, leading to suboptimal color correction results.
Innovation Solution
A projector system that includes a measurement unit with a light receiving element and an optical filter to change light receiving characteristics, allowing for accurate measurement and correction of image light colors by converting between RGB and XYZ color systems, using a Z filter to align with human eye sensitivity, and an optical modulation unit to generate image light from solid light sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a standard color measuring device is used to measure image light color, then the measurement process is simple, but the measurement accuracy is insufficient due to mismatch between device spectral sensitivity and human eye sensitivity
Solution Approach 1:
The patent introduces an optical filter as an intermediary component between the light receiving element and the measurement process. This filter converts the spectral characteristics of the measurement device to match human eye sensitivity (XYZ color space), enabling accurate color measurement without requiring the entire measurement system to be redesigned. The filter acts as a mediator that bridges the gap between device capabilities and human perception requirements.
Solution Approach 2:
The patent changes the spectral response parameters of the light receiving element by introducing an optical filter with specific transmission characteristics. This parameter change allows the measurement device to operate in the XYZ color space that matches human eye sensitivity, rather than the device's native RGB spectral response. The filter modifies the effective spectral sensitivity parameters to align with human perception.
2Measurement precision
If color correction is performed based on simple RGB measurement, then the correction process is fast, but the color correction accuracy is insufficient
Solution Approach 1:
The patent performs preliminary conversion of RGB measurement values to XYZ color space values before conducting color correction. This preliminary action ensures that the correction is based on human eye sensitivity characteristics from the outset, rather than requiring complex post-correction transformations. The conversion is performed once at the beginning, and subsequent correction operations work directly in the perceptually relevant XYZ space.
Solution Approach 2:
The XYZ color space serves as an intermediary representation that bridges device measurements and human perception. By converting RGB measurements to XYZ and performing correction in this intermediate space, the system achieves both accuracy (matching human sensitivity) and efficiency (avoiding iterative transformations). The XYZ space acts as a mediator that simplifies the correction process while maintaining perceptual accuracy.
3Measurement precision
If multiple color filters are used to measure all XYZ color components, then complete color measurement is achieved, but the device complexity and measurement time increase
Solution Approach 1:
The patent extracts only the essential measurement information needed for color correction. Instead of measuring all XYZ components with separate filters, the system uses a single optical filter to modify the light receiving element's characteristics, extracting the necessary colorimetric data through a simplified measurement process. This extraction approach obtains sufficient information for accurate correction without the overhead of complete multi-filter measurement.
Solution Approach 2:
The optical filter is designed to provide multi-functional capability, enabling the light receiving element to measure color information in the XYZ color space that matches human eye sensitivity. A single filter configuration allows the system to perform measurements that would otherwise require multiple specialized filters, achieving universal color measurement capability with reduced complexity and measurement time.
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
Enables high-accuracy color measurement and correction of image light, aligning with human eye sensitivity, thereby improving color reproduction and consistency.
Implementation Method 1
an optical filter that changes light receiving characteristics of the light receiving element
Implementation Method 2
the light source optical system may obtain color light having a predetermined color by causing the color light emitted by the solid light source to abut against a phosphor
Data Source
AI summary
A projector includes a measurement unit, a correction parameter generation unit, and an image processing unit. The measurement unit measures a color of an image formed on a projection surface in terms of a plurality of colors constituting an RGB color system and at least one color constituting an XYZ color system. The correction parameter generation unit generates a correction parameter based on a conversion value and a second measurement value of the color, which is measured by the measurement unit among the colors constituting the XYZ color system. The conversion value is obtained by converting a first measurement value of the color in the RGB color system, which is measured by the measurement unit, into the color in the XYZ color system. The image processing unit corrects image light with the correction parameter.