Projection system and method of driving a projection system
A projection system and method includes a light source configured to emit a light in response to an image data; a phase light modulator configured to receive the light from the light source and to apply a spatially-varying phase modulation on the light; and a controller configured to determine, for a frame of the image data, a plurality of phase configurations, respective ones of the plurality of phase configurations corresponding to solutions of a phase algorithm and representing the same image with a different modulation pattern, and provide a phase control signal to the phase light modulator, the phase control signal configured to cause the phase light modulator to modulate the plurality of phase configurations in a time-divisional manner within a time period of the frame, thereby to project a series of subframes within the time period.
1 . A projection system, comprising:
a light source configured to emit a light in response to an image data;
a phase light modulator configured to receive the light from the light source and to apply a spatially-varying phase modulation on the light to generate an output image;
and
a controller configured to:
determine, for a frame of the image data, a plurality of phase configurations, respective ones of the plurality of phase configurations corresponding to solutions of iterations of a phase algorithm and representing the same image with a different modulation pattern, and
provide a phase control signal to the phase light modulator, the phase control signal configured to cause the phase light modulator to modulate light in accordance with the plurality of phase configurations in a time-divisional manner within a time period of the frame, thereby causing the projection system to project a series of subframes within the time period to form the output image on a screen, wherein the phase algorithm is based on a compensation map for modifying a target intensity of the image data or on a scaling transformation for modifying an effective resolution of the image data.
2 . The projection system according to claim 1 , wherein the plurality of phase configurations is 60 phase configurations.
3 . The projection system according to claim 1 , wherein the phase algorithm is initialized with a random or pseudorandom seed.
4 . The projection system according to claim 1 , wherein the phase algorithm is configured to establish a bidirectional mapping between a field at a modulation plane where the phase light modulator is disposed, and a field at a reconstruction plane where an image is formed by the phase light modulator.
5 . The projection system according to claim 1 , wherein the image data has an image resolution, the phase light modulator has a modulation resolution corresponding to a number of pixel elements in the phase light modulator, and the modulation resolution is lower than the image resolution.
6 . The projection system according to claim 5 , wherein the image resolution is four times the modulator resolution.
7 . The projection system according to claim 1 , wherein the phase light modulator includes a plurality of pixel elements arranged in an array, and circuitry configured to modify respective states of the plurality of pixel elements in response to the phase control signal.
8 . The projection system according to claim 1 , wherein the phase light modulator is a digital micromirror device or a liquid-crystal-on-semiconductor device.
9 . The projection system according to claim 1 , wherein the controller is configured to initialize the phase algorithm with a seed distribution.
10 . The projections system according to claim 9 , wherein the controller is configured to determine the seed distribution for the frame based on a reconstruction field from a preceding frame.
11 . The projection system of claim 9 , wherein the controller is configured to dynamically determine, for the frame, whether to generate the seed distribution anew or to base the seed distribution on a preceding frame.
12 . A method of driving a projection system, comprising:
emitting a light by a light source, in response to an image data;
receiving the light by a phase light modulator;
applying a spatially-varying phase modulation on the light by the phase light modulator, thereby generating an output image;
for a frame of the image data, determining a plurality of phase configurations, respective ones of the plurality of phase configurations corresponding to solutions of iterations of a phase algorithm and representing the same image with a different modulation pattern; and
providing a phase control signal to the phase light modulator, and thereby causing the phase light modulator to modulate light in accordance with the plurality of phase configurations in a time-divisional manner within a time period of the frame, and thereby projecting a series of subframes within the time period to form the output image on the screen, wherein the phase algorithm is based on a compensation map for modifying a target intensity of the image data or on a scaling transformation for modifying an effective resolution of the image data.
13 . The method according to claim 12 , further comprising establishing, by the phase algorithm, a bidirectional mapping between a field at a modulation plane where the phase light modulator is disposed, and a field at a reconstruction plane where an image is formed by the phase light modulator.
14 . The method according to claim 13 , wherein the bidirectional mapping is a Rayleigh-Sommerfeld propagation.
15 . The method according to claim 13 , wherein the phase algorithm iteratively generates the bidirectional mapping to generate a solution for the field at a modulation plane that is free from amplitude information, based on a target of the field at the reconstruction plane.
16 . The method according to claim 12 , further comprising initializing the phase algorithm with a seed distribution.
17 . The method according to claim 16 , wherein the seed distribution is a uniform distribution and/or wherein the seed distribution is generated by applying an iterative algorithm to a random phase pattern and/or wherein the seed distribution for the frame is based on a reconstruction field from a preceding frame.
18 . The method of claim 16 , further comprising, for the frame, dynamically determining whether to generate the seed distribution anew or to base the seed distribution on a preceding frame.
19 . A non-transitory computer-readable medium storing instructions that, when executed by a processor of a projection system, cause the projection system to perform operations comprising the method according to claim 12 .