Abstract: An optical device including an illuminant for emitting light; light condensing element composed of a reflecting mirror whose shape of reflecting plane is of rotational secondary curved surface and a condenser lens for converging approximately parallel fluxes; a mixing rod whose section is quadrangle, first lens element composed of at least one lens; and a reflecting optical element which is disposed near the position where a plurality of tertiary illuminants are formed and which reflects light in a desired direction. This optical device allows a distribution of illuminance whose intensity is highly uniform to be obtained even when a light flux is inputted from a direction inclined from the normal direction of the plane-to-be-illuminated by illuminating the optical device disposed out of an optical axis of the illuminator.

Abstract: The illumination system comprises a light source; a first lens array of small lenses for dividing light from the light source into a plurality of light beams; and a second lens array of small lenses corresponding to the small lenses of the first lens array. The second lens array is located near where the plurality of light beams from the first lens array are converged. Each small lens of the second lens array has an outer shape of a non-rectangular polygon which is related to a profile of the light converged by a corresponding small lens of the first lens array. The second lens array may have a flat portion provided between the columns of the small lenses.

Abstract: The invention relates to objective arrangements for use in projection systems such as overhead projectors. An objective arrangement 10 provides a tilted image plane. The arrangement 10 is rotationally asymmetric by virtue of the third element 16 having a principal optical axis 22 which is displaced to one side, but parallel with the principal optical axes 20 of the first and second elements 12,14. This asymmetry has been found to correct aberrations introduced by a tilted Fresnel lens used in the projection arrangement.

Abstract: In order to minimize light diffraction along the direction of switching and more particularly light diffraction into the acceptance cone of the projection optics, in the present invention, mirrors are provided which are not rectangular. Also, in order to minimize the cost of the illumination optics and the size of the display unit of the present invention, the light source is placed orthogonal to the rows (or columns) of the array, and/or the light source is placed orthogonal to a side of the frame defining the active area of the array. The incident light beam, though orthogonal to the sides of the active area, are not however, orthogonal to any substantial portion of sides of the individual mirrors in the array. Orthogonal sides cause incident light to diffract along the direction of mirror switching, and result in light ‘leakage’ into the on-state even if the mirror is in the off-state. This light diffraction decreases the contrast ratio of the mirror.

Abstract: A cooling device of liquid crystal projector is utilized to cool a liquid crystal panel and polarizer of an optical system in a liquid crystal projector; when the optical system of the present invention is heated by a light projection, coolant will carry the heat of the liquid crystal panel and polarizer of the optical system away, and a flow guiding device is used to lead the coolant to flow so as to cool the high temperature coolant by means of a heat dissipating device, then the heat is dissipated to outside environment thereby. After the temperature of the coolant is lowered, it is led to flow through the liquid crystal panel and polarizer again by means of the flow-guiding device, so as to repeat a cooling cycle.

Abstract: A front projection system and associated method are disclosed that correct distortion for a front projector device. The front projector device is characterized by off-axis optics and a throw-to-screen diagonal ratio of at most 1 which generate distortion including pincushion, keystone and anamorphic distortion components. Further, the projection device has an electronic distortion correction component operable to pre-distort an image prior to projection in order to correct for the pincushion, keystone and anamorphic distortion components of the projector device. Further, an associated method is also disclosed for correcting distortion generated in a projection system by a combination of optical and electronic correction. The method comprises setting a limit on the amount of image information that is acceptable to lose through the optical components, and selecting an optical solution is comprising optics having inherent distortion within the set limit.

Abstract: A cylindrical color wheel that is adaptive for making a slim-type picture projector. In the cylindrical color wheel, a color drum is provided with a plurality of color filters for transmitting only a light beam having a wavelength corresponding to a different color being integrally formed in a cylinder shape. A coupler is attached to the color drum. A motor rotates the coupler to which the color drum is attached.

Abstract: A projection-type display device for displaying an image using a projector device emitting optical images spatially modulated by reflection-type liquid crystal panels onto a screen, wherein phase difference plates are arranged at the incidence planes of the reflection-type liquid panels so as to cancel out the retardation comprised of the retardation corresponding to one-quarter of the wavelength of the incident light due to the polarization beam splitter plus the retardations due to the dichroic mirrors of the color separating and synthesizing means, whereby it is possible to make the illumination light leaking from the polarization beam splitter to the projection lens at the black level portions extremely small and possible to prevent a reduction in the contrast due to the haze phenomenon.

Abstract: An image projection system for generating an image on a projection screen using a highly compact geometry. The optical system uses polarized light manipulated by at least one of a conicoid, or plane optical elements to effect a folded mirror system to project an image onto the screen.

Abstract: A projector including an illumination system that illuminates a modulation device modulating light according to image information. The illumination system includes a light source that emits a light beam along a light source optical axis, a first lens array having a plurality of small lenses which divide the light beam emitted from the light source into a plurality of partial light beams, a superimposing lens that superimposes the plurality of partial light beams emitted from the first lens array on the modulation device, and an entrance angle reducing system disposed between the superimposing lens and the modulation device. The entrance angle reducing system reduces an entrance angle of light rays, which are emitted from the superimposing lens and enter the modulation device, compared with an illumination system without the entrance angle reducing system.

Abstract: An apparatus for compensating a projected image employs a projected image compensator, such as a suitably programmed graphics processor or other processing device, and receives projection display compensation parameters to perform electronic projected image correction based on the received projection on display compensation parameters. The projected image compensator obtains stored final image data, such as data finally rendered by a 2D or 3D graphics engine, that has been stored in a frame buffer, and performs scaling of the final image data to produce projection compensated final image data. In one embodiment, the projection compensated final image data is stored back in the frame buffer memory and then output under control of a display controller. In another embodiment, the projection compensated final image data is not returned back to the frame buffer memory.

Abstract: A digital image projector includes an illumination-light source lamp and illumination beam forming optics for forming a white-spectrum illumination beam and color-band-separation optics to divide the illumination beam into color-component subbeams. The digital image projector also includes a reflective digital-image-encoding polarization modulator mechanism such as a reflective liquid crystal display polarization modulator to reflectively modulate the linearly polarized subbeams to form color-component image encoded-polarization subbeams and projection lens optics for projecting a color image divided from the image encoded-polarization subbeams.

Abstract: A method of fabricating a display system includes bonding a silicon substrate to a second substrate with an insulating layer. The silicon substrate is thinned to form a thin film silicon-on-insulator (SOI) structure. A matrix display circuit is formed with the SOI structure. A light shield pattern is formed over regions of the matrix display circuit. A light source, the matrix display circuit and a magnifying lens are positioned within a display housing such that light from the light source is directed onto the display and an image on the display is magnified by the lens for viewing by a user.

Abstract: A monocentric arrangement of optical components providing stereoscopic display of a virtual image, electronically generated, line by line, from a linear image source (36) and projected, as a real intermediate image, near the focal surface (22) of a curved mirror (24) by means of a scanning ball lens assembly (100). To form each left and right intermediate image component, a separate image generation system (70) comprises a scanning ball lens assembly (100) comprising a spherical lens (46) for wide field of view and a reflective surface (102). A monocentric arrangement of optical components images the left and right scanning ball lens pupil at the corresponding left and right viewing pupil (14) of the observer (12) and essentially provides a single center of curvature for projection components. Use of such a monocentric arrangement with linear image source (36) and scanning ball lens assemblies (100) provides an exceptionally wide field of view with large viewing pupil (14).

Abstract: A digital projector for providing digital images for display to a user, the digital projector comprises a housing having its vertical dimension substantially greater than its horizontal dimension; a light source enclosed within the housing for providing light; a digital imager through which the light of the light source is projected for providing digital images for display to the user; a single mirror for reflecting the digital image from the digital imager; and a lens for receiving the digital image from the digital imager for display external to the digital projector; and a plurality of wheels attached to the base for providing efficient movement of the digital projector.

Abstract: For providing a rear-projection type display apparatus, and a translucent type sheet for use therein, in particular, using an image modulation element, such as, a liquid crystal or a DMD (Digital Micro-mirror Device), etc.

Abstract: In a projection arrangement with a projector and a deflecting mirror in which the image projection, proceeding from a projection direction along a principal projection axis impinges on the deflecting mirror which is supported so as to be movable in two spatial direction and whose mirror surface deflects a projected light bundle at an elevation angle and at an azimuth angle onto a projection surface standing on the ground the image projection is effected from the direction of a zenith at an angle &bgr; which is less than 60° in relation to a vertical line from the zenith and the deflecting mirror is arranged at the ground wherein the projected light bundle can be deflected toward the projection surface so that an image can be generated on the projection surface and moved on the latter.

Abstract: A projection system includes a projecting portion for projecting image light onto a predetermined projection receiving portion, an image taking portion for taking a projected image obtained by the projecting portion, and a processing portion for performing a predetermined processing based on the image taking result obtained by the image taking portion. An image taking lens of the image taking portion is arranged outside the reflection region of the direct reflection light of the projected image.

Abstract: An image projecting apparatus is provided to project a real image of an object to be displayed while obscuring the object from view by an observer located exteriorly of the image projecting apparatus. The apparatus includes a housing (12) having an interior and a view area (14) for the real image. First and second reflective surfaces (40, 50), such as mirrors, are disposed in the housing. The first reflective surf (40) must be concave of a variety of geometric shapes. The second reflective surface (50) may be concave or, alternatively, planar. A masking member is interposed between the object and the view area. The second reflective surface can define the masking member. The first and second reflective surfaces are arranged at an acute angle to each other.

Abstract: A video projector using a reflection type optical modulation element whose lens system is simple in configuration and which can produce a high-brightness, high-contract projected image.