Display Controller Uniform Luminance via Pixel Limit
Solution Overview
Problem
In display systems, particularly projectors, the maximum luminance value that can be displayed varies across pixels, leading to non-uniform luminance when trying to display images with uniform absolute luminance values, causing viewer discomfort due to visible luminance differences.
Innovation Solution
A display controller that acquires the upper limit luminance value for each pixel, sets a set luminance value lower than the maximum for each pixel, and generates output gradation values to ensure the displayed luminance is equal to or smaller than the set value, thereby maintaining uniformity across the image.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the maximum value of absolute luminance is used for each pixel to realize the designated absolute luminance value, then the luminance value can be maximized for pixels with high display capability, but non-uniform luminance becomes visible in the displayed image
Solution Approach 1:
The patent applies parameter changes by introducing a set luminance value that is lower than the maximum displayable luminance for each pixel. The output gradation value generation unit calculates output gradation values based on this set luminance value rather than the maximum possible value, thereby changing the operating parameter to ensure uniform luminance across all pixels while maintaining acceptable brightness levels.
Solution Approach 2:
The patent applies local quality by individually determining the set luminance value for each pixel based on its specific upper limit luminance value. Each pixel's output is controlled according to its local capabilities, with pixels having higher maximum luminance values receiving higher set luminance values than pixels with lower maximum luminance values, thereby achieving uniform overall luminance while preserving local display quality.
2Object-affected harmful factors
If different set luminance values are used for different pixels based on their upper limit luminance values, then uniform luminance can be maintained across the image, but the complexity of the output gradation value generation increases
Solution Approach 1:
The patent applies preliminary action by pre-determining the set luminance value for each pixel before actual image display. The upper limit luminance values for all pixels are acquired and used to establish the set luminance values in advance, so that during normal operation, the output gradation value generation unit only needs to reference these pre-established values rather than performing complex real-time calculations for each pixel.
Data Source
AI summary
A display controller includes: an upper limit luminance value acquisition unit configured to acquire, for pixels of display devices, an upper limit luminance value of an absolute luminance value; a set luminance value setting unit configured to set a set luminance value so that the set luminance value is smaller than a maximum value among the upper limit luminance values; an input luminance value acquisition unit configured to acquire an input luminance value based on input data; an output gradation value generation unit configured to generate an output gradation value based on the input luminance value and the set luminance value; and an output controller configured to output the generated output gradation value, wherein the output gradation value generation unit is further configured to generate the output gradation value so that an output luminance value is equal to or smaller than the set luminance value.