Abstract: A method for optimizing cost and performance in a lens assembly is disclosed. The method relaxes the constraints of optically correcting lateral chromatic aberration and distortion on the lens assembly and instead electronically corrects for lateral chromatic aberration and distortion. As a result the lens assembly transmissivity and MTF improve dramatically and other aberrations are reduced as a result of re-optimizing the lens assembly merit function. The cost and volume of the lens assembly are reduced as well. The optimized lens assembly could be used in rear or front projection display devices as a well as image acquisition devices.

Abstract: An ultra-thin rear projection display system (RPDS) is disclosed. The system uses a small flat mirror, a small non-rotationally symmetric mirror and a larger non-rotationally symmetric mirror to achieve a D-to-d ratio of around 11:1 while rendering a significantly distortion free image on the screen. The first two mirrors are significantly smaller than the size of the screen, while the third mirror is significantly larger than the first two mirrors but smaller than the screen. In one embodiment, the lens and light engine are positioned horizontally to one side and, in another example, the lens and light engine are positioned vertically, projecting downwards. In one example, an image processor is used to correct for the remaining distortions. In another example, the system is adapted such that the light rays forming the projected image are within a certain range of angles such that a TIR Fresnel lens could be used to collimate the image.

Abstract: An electronic correction system and method for correcting optical anomalies, namely distortions, color non-convergence (excluding axial chromatic aberration) and luminance (or chrominance) non-uniformity. Each effect is modeled as a transformation in either spatial (positional) space or color space. Representing the effects as transformations of digital pixel data, allows the different anomalies to be resolved within a common framework, namely that of image ‘warping’. The anomaly, having been expressed as a pixel transformation, is then eliminated by electronically applying the inverse transformation. This process is equivalent to digitally manipulating or warping the image in position and/or color space and accordingly this can be achieved using commercially known warping circuits. In addition, the transformation can also contain a component to additionally perform any application specific image warping (e.g. scaling and geometric transformations).

Abstract: A method for optimizing cost and performance in a lens assembly is disclosed. The method relaxes the constraints of optically correcting lateral chromatic aberration and distortion on the lens assembly and instead electronically corrects for lateral chromatic aberration and distortion. As a result the lens assembly transmissivity and MTF improve dramatically and other aberrations are reduced as a result of re-optimizing the lens assembly merit function. The cost and volume of the lens assembly are reduced as well. The optimized lens assembly could be used in rear or front projection display devices as a well as image acquisition devices.

Abstract: An image projection system and method is presented for optically projecting an image onto a display surface with visually correct geometry and optimum image quality. The projection system includes an image processing unit for receiving the input image data and generating distortion-compensated image data to compensate for ensuing spatial distortions in the projection system, a projection light engine for receiving the distortion-compensated image data and projecting a distortion-compensated optical image that corresponds to the distortion-compensated image data; and, an optical reflection assembly comprising at least one curved mirror positioned in the optical path of the distortion-compensated optical image emerging from the projection light engine for producing a displayed optical image with reduced distortion on the display surface.

Abstract: A rear projection display system (RPDS) and associated optical system are described with a reduced field angle. The RPDS includes a screen and a housing. The optical system includes a light engine, a first mirror, a second mirror and a Fresnel lens arranged to achieve a thin housing. The light engine is generally disposed in an upper region of the housing, and projects light onto the first mirror, which can be located at a bottom portion of the housing. The first mirror reflects the projected light onto the second mirror, which in turns reflects the light towards the Fresnel lens, which transfers the light onto the screen. A total internal reflection Fresnel lens is used to reduce cost and complexity without sacrificing image quality and housing thinness. An image processing device can also be used to compensate for geometric and optical distortions in the final image displayed on the screen.

Abstract: An ultra-thin rear projection display system (RPDS) is disclosed. The system uses a small flat mirror, a small non-rotationally symmetric mirror and a larger non-rotationally symmetric mirror to achieve a D-to-d ratio of around 11:1 while rendering a significantly distortion free image on the screen. The first two mirrors are significantly smaller than the size of the screen, while the third mirror is significantly larger than the first two mirrors but smaller than the screen. In one embodiment, the lens and light engine are positioned horizontally to one side and, in another example, the lens and light engine are positioned vertically, projecting downwards. In one example, an image processor is used to correct for the remaining distortions. In another example, the system is adapted such that the light rays forming the projected image are within a certain range of angles such that a TIR Fresnel lens could be used to collimate the image.

Abstract: A projector assembly and method for automatically correcting keystone distortion includes an image correction engine, a light engine, a projection lens having a projection axis, a processor, a directional sensor and an inclination sensor. The sensors determine the absolute vertical and horizontal direction of the projection axis. The inclination sensor determines the vertical zero reference. The direction sensor is used to determine the horizontal zero reference. The processor calculates vertical and horizontal difference angles between the absolute directions and zero reference values in the vertical and horizontal directions. Using difference angles, the processor calculates the keystone distortion and instructs the image correction engine to apply geometric and brightness correction to the image data proportional and inverse to the keystone distortion and lens parameters (field of view, focal length, imperfections, etc) such that the image projected onto a viewing screen, is free from keystone distortion.

Abstract: An image projection system and method is presented for optically projecting an image onto a display surface with visually correct geometry and optimum image quality. The projection system includes an image processing unit for receiving the input image data and generating distortion-compensated image data to compensate for ensuing spatial distortions in the projection system, a projection light engine for receiving the distortion-compensated image data and projecting a distortion-compensated optical image that corresponds to the distortion-compensated image data; and, an optical reflection assembly comprising at least one curved mirror positioned in the optical path of the distortion-compensated optical image emerging from the projection light engine for producing a displayed optical image with reduced distortion on the display surface.

Abstract: An electronic correction system and method for correcting optical anomalies, namely distortions, color non-convergence (excluding axial chromatic aberration) and luminance (or chrominance) non-uniformity. Each effect is modeled as a transformation in either spatial (positional) space or color space. Representing the effects as transformations of digital pixel data, allows the different anomalies to be resolved within a common framework, namely that of image ‘warping’. The anomaly, having been expressed as a pixel transformation, is then eliminated by electronically applying the inverse transformation. This process is equivalent to digitally manipulating or warping the image in position and/or color space and accordingly this can be achieved using commercially known warping circuits. In addition, the transformation can also contain a component to additionally perform any application specific image warping (e.g. scaling and geometric transformations).

Abstract: A projector assembly and projection method for determining the amount of keystone distortion present in projection system and automatically correcting said distortion. The projection assembly includes an image correction engine, a light engine, projection lens having a projection axis, a processor, a directional sensor and an inclination sensor. The sensors determine the absolute vertical and horizontal direction of the projection axis and the processor calculates the vertical and horizontal difference angle by calculating the difference between the absolute vertical and horizontal directions and the vertical and horizontal zero references. The vertical zero reference is determined by the inclination sensor.