Color and luminance control system for liquid crystal projection displays
First Claim
1. A light modulator display apparatus including a color and luminance control system that compensates for display component transfer function-induced luminance and color variations by providing a substantially uniform overall transfer function of primary color input information to a spectral output having a predetermined luminance and a predetermined color balance ratio, comprising:
- a light source providing primary color illumination in amounts establishing a light source luminance and an illumination color balance ratio;
a light modulator display device having a substantially nonlinear transfer function receiving the light source luminance and illumination color balance ratio and providing the spectral output in response to display driving signals;
a gain controller receiving the primary color information and providing gain-adjusted amounts of the primary color information to compensate for the illumination color balance ratio and establish the predetermined color balance ratio; and
a light modulator display device transfer function converter receiving the gain-adjusted amounts of primary color information and providing the display driving signals in amounts that compensate for the nonlinear transfer function while maintaining in the spectral output the predetermined color balance ratio.
14 Assignments
0 Petitions
Accused Products
Abstract
A liquid crystal display ("LCD") projection unit (12) employs a luminance and color balance system having a lookup table (100) storing multiple sets of gain and/or gamma corrected responses (92-99) for color balance and luminance control. The lookup table values are determined by measuring an S-curve response (90) of an LCD array (40) for each of a set of R, G, and B input data values, converting the S-curve responses to a corresponding set of gamma responses, and scaling the gamma responses to generate red ("R"), green ("G"), and blue ("B") families of gain and gamma corrected values. Color balance is adjusted by selecting the particular R, G, and B families of gain and gamma corrected values that cause the LCD projection unit to match a predetermined ratio of maximum R, G, and B luminance values. Luminance is adjusted by selecting families of lookup table values that adjust the transmittance of the LCD while maintaining the color balance. The LCD projection unit achieves a uniform luminance and color balance that renders it suitable for use in a multiscreen display system (10).
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Citations
21 Claims
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1. A light modulator display apparatus including a color and luminance control system that compensates for display component transfer function-induced luminance and color variations by providing a substantially uniform overall transfer function of primary color input information to a spectral output having a predetermined luminance and a predetermined color balance ratio, comprising:
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a light source providing primary color illumination in amounts establishing a light source luminance and an illumination color balance ratio; a light modulator display device having a substantially nonlinear transfer function receiving the light source luminance and illumination color balance ratio and providing the spectral output in response to display driving signals; a gain controller receiving the primary color information and providing gain-adjusted amounts of the primary color information to compensate for the illumination color balance ratio and establish the predetermined color balance ratio; and a light modulator display device transfer function converter receiving the gain-adjusted amounts of primary color information and providing the display driving signals in amounts that compensate for the nonlinear transfer function while maintaining in the spectral output the predetermined color balance ratio. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. In a light modulator display apparatus, a method of compensating for display component transfer function-induced luminance and color variations by providing a substantially uniform overall transfer function of primary color input information to a spectral output having a predetermined luminance and a predetermined color balance ratio, the method comprising:
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providing primary color illumination in amounts establishing a light source luminance and an illumination color balance ratio; receiving the light source luminance and illumination color balance ratio at a light modulator display device having a substantially nonlinear transfer function and providing the spectral output in response to display driving signals; providing gain-adjusted amounts of the primary color information to compensate for the illumination color balance ratio and establish the predetermined color balance ratio; and receiving the gain-adjusted amounts of primary color information and providing the display driving signals in amounts that compensate for the nonlinear transfer function while maintaining in the spectral output the predetermined color balance ratio. - View Dependent Claims (17, 18, 19, 20, 21)
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Specification