Multi-half-tone imaging and dual modulation projection/dual modulation laser projection
AssigneeDolby Laboratories Licensing Corporation
InventorsMartin J. Richards, Jerome Shields
Life of this patent
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Abstract
Smaller halftone tiles are implemented on a first modulator of a dual modulation projection system. This techniques uses multiple halftones per frame in the pre-modulator synchronized with a modified bit sequence in the primary modulator to effectively increase the number of levels provided by a given tile size in the halftone modulator. It addresses the issue of reduced contrast ratio at low light levels for small tile sizes and allows the use of smaller PSFs which reduce halo artifacts in the projected image and may be utilized in 3D projecting and viewing.
Claims20
A method for preparing dual modulation energization signals for a dual modulation display comprising a light source illuminating a pre-modulator, a set of relay optics transmitting the light from the pre-modulator to a primary modulator, the method comprising:
- determining a set of pre-modulator energization signals, the signals applied for more than one time period per single frame, whereby each pre-modulator energization signals induces the pre-modulator to create a plurality of half-tone images to be displayed or energized on a pre-modulator of a dual modulation display system over a plurality of sub-frames time periods during a single frame time period, such that the plurality of half-tone images that produces a desired Point Spread Function (PSF) that compensates for imperfections in the set of relay optics, wherein further the single frame period is a modulation period of the primary modulator and the sub-frame time period is a modulation period of the pre-modulator and the pixel elements of the primary modulator are switched on/off once during the single frame period and the pixel elements of the pre-modulator are switched on/off once during a single sub-frame period and further that the single frame period comprises a plurality of sub-frame time periods;
- determining a set of primary modulator signals, the primary modulator signals energized in synchronization with the pre-modulator energization signals to produce an image to be displayed or energized on a primary modulator of the dual modulation display system.
A display device comprising a dual modulation architecture, comprising:
- a pre-modulator configured to produce a low resolution image comprising pixels each pixel comprising a plurality of modulating elements of the first modulator, the pixels together forming the low resolution image;
- a set of relay optics configured to transmit light from the pre-modulator, the relay optics comprising a given transfer function that include imperfections whereby the pre-modulator is energized by a set of pre-modulator energization signals that produce a plurality of half-tone images to be displayed or energized on a pre-modulator of a dual modulation display system over a plurality of sub-frames time periods during a single frame time period that compensate for the imperfections of the relay optics, wherein further the single frame period is a modulation period of the primary modulator and the sub-frame time period is a modulation period of the pre-modulator and the pixel elements of the primary modulator are switched on/off once during the single frame period and the pixel elements of the pre-modulator are switched on/off once during a single sub-frame period and further that the single frame period comprises a plurality of sub-frame time periods;
- a primary modulator comprising a plurality of modulating element configured to further modulate the light transmitted from the set of relay optics with a set of primary modulator energization signals working in synchronization with the pre-modulator energization signals so as to produce a desired image for display.
Dependencies are inferred from the claim text.