Abstract: In order to minimize light diffraction along the direction of switching and more particularly light diffraction into the acceptance cone of the collection optics, in the present invention, micromirrors 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, is not however, orthogonal to any substantial portion of sides of the individual micromirrors in the array. Orthogonal sides cause incident light to diffract along the direction of micromirror switching, and result in light ‘leakage’ into the ‘on’ state even if the micromirror is in the ‘off’ state. This light diffraction decreases the contrast ratio of the micromirror.

Abstract: A color projection system includes a lamp and at least one diffraction grating or at least one prism that diffracts light from the lamp onto an LC microdisplay panel. By moving either the at least one diffraction grating or the at least one prism with respect to the incident light from the lamp, the diffracted light received by the LC microdisplay panel sequentially comprises red, green, and blue light.

Abstract: A single-panel color image display apparatus realizing a wide color gamut is provided. The single-panel color image display apparatus includes a colored light separator having a plurality of dichroic filters in which a dichroic filter reflecting a red light beam may be disposed lastly among the plurality of dichroic filters. The single-panel color image display apparatus may include a scrolling unit having a mask at a boundary portion between spiral lens cells.

Abstract: A flat mirror for folding an optical path in a casing of a rear projection television is arranged in the casing on not the side of a screen but a rear or upper side of the casing. In order to direct an optical path of an image projection to a flat mirror on a rear or upper side of the casing, a plurality of focusing mirrors, with which a light beam can be directed at a large angle with respect to a normal line of the screen and can focus an image through a shorter distance compared with a conventional lens system, are used. Since the light beam projected by the focusing mirrors is directed at high angle and reflected by the rear or upper side flat mirror in the casing, the light beam is focused on the screen provided on a front side of the casing.

Abstract: A projection television set having an enclosure housing a screen, an optical unit and a mirror, wherein the optical unit and mirror are capable of projecting an image onto the screen. The enclosure is preferably constructed from hollow plastic extruded panels. In addition, the enclosure preferably includes a duct extending upwardly from a lower portion of the enclosure to exhaust heat radiating from components housed therein to the exterior of the enclosure toward the top of the enclosure.

Abstract: A prism is mounted onto a motor without regard to its rotation angle relative to the motor index. Its position is electronically set later after construction of the optical path. A motor controller is used to control the rotation of the prism. This motor controller keeps the prism spinning at a constant velocity and positions the prism phase (rotation angle versus time). A variable offset is used to position the absolute prism rotation as a function of time. The phase may be advanced or delayed by an operator during set up. Each prism has its own phase. The phase of each prism in the system is set so that the illumination pattern correctly matches the video addressing of the panel. This is a one time set up during construction. The correct positions are set, and stored in non-volatile memory for life.

Abstract: A scanner phase control for a scrolling color projector utilizes the back-EMF value of a motor which rotates a prism of the scanner to set a reference point for the prism. A reference phase signal is provided which corresponds to timing information of the scan of a stripe of light provided by the prism. The phase of the motor is altered in response to the reference phase signal such that the back-EMF zero crossings of the motor coincide with the beginning of a scan as identified by the reference phase signal.

Abstract: The projector comprises a light source that emits illuminating light, a single modulation panel, a projection optical system, a color filter mechanism, a converging optical system that converges the illuminating light on a filter surface of the color filter mechanism, and a controller for controlling the color filter mechanism and the single modulation panel. The color filter mechanism includes a rotatable filter rotor having a plurality of color filters and a plurality of light-blocking mask bands provided at the boundaries of the color filters, and a filter driver that rotates the filter rotor. The converging optical system converges the illuminating light such that the size of the illuminating light spot on the filter surface is smaller than the individual color filters.

Abstract: A light source optical system capable of forming an image having good balance in brightness of red, blue, and green color light, having high overall brightness, and having good color reproducibility, on a screen is provided. The light source optical system has a first lamp, a second lamp, and a condensing optical system for synthesizing a first light emitted from the first lamp and a second light emitted from the second lamp to form irradiation light. The light source optical system is characterized in that the first light and the second light have mutually differing spectral distributions.

Abstract: A laser beam display includes at least a first and second plurality of laser beam sources, each of which may preferably be an array of semiconductor lasers, providing a plurality of laser beams in an optical path so as to reflect off of reflective facets of a movable reflector and illuminate a display screen. In a color display, each column of the laser array corresponds to a separate primary color. The separate rows of each array correspond to independently activated but simultaneously driven scan lines to be illuminated by the laser beam scanning apparatus. The plural laser beam arrays subdivide the width of the screen into smaller scan segments to increase the scanning angle or increase the horizontal scanning speed of the apparatus. Tilted facets illuminate different vertical sections of the screen with the laser beams as the reflector rotates. A scan format employing simultaneously illuminated diagonal scan tiles provides optimal use of the plural laser beam arrays.

Abstract: A light-modulating system, includes: a light source for emitting a sequence of light pulses at a period Tp; a light modulator having a variable-width switching profile with rise and fall times Tr and Tf respectively, wherein the greater of Tr and Tf is greater than Tp, the light modulator modulating the sequence of light pulses; and a controller for controlling the width of the variable-width light switching profile.

Abstract: A projection television set having an enclosure housing a screen, an optical unit and a mirror, wherein the optical unit and mirror are capable of projecting an image onto the screen. The enclosure is preferably constructed from hollow plastic extruded panels. In addition, the enclosure preferably includes a duct extending upwardly from a lower portion of the enclosure to exhaust heat radiating from components housed therein to the exterior of the enclosure toward the top of the enclosure.

Abstract: A full color video projector system using a light source and a single light valve. The output of the light source passes through a condenser lens. The lens is directed toward a splayed array of red, green, and blue dichroic reflector color filters. The reflected three primary color beams first pass through a lenticular lens array, comprised of a plurality of elongated cylinder lenses, arranged in parallel, co-planar relation. The lenticular array produces color stripe illumination pattern, which is redirected and focused by a relay optic upon a reflective micro-mirror light valve. The light valve includes three sub-pixels for every full-color screen pixel. The pixels are arranged in parallel stripes which correspond to the size and configuration of the color strip illumination pattern outputted by the lenticular array. Light valve address circuitry actuates appropriate sub-pixels to reflect incident light energy, in accordance with corresponding video image information.

Abstract: The present invention provides a high brightness color selective light modulator (CSLM) formed by apolarization modulator positioned between two retarder stacks. The modulator changes the apparent orientation of one retarder stack relative to the other so that, in a first switching state of the modulator the two retarder stacks cooperate in filtering the spectrum of input light, and in a second switching state the two retarder stacks complement each other, yielding a neutral transmission spectrum. Two or more CSLM stages can be used in series, each stage providing independent control of a primary color. One preferred embodiment eliminates internal polarizers between CSLM stages, thereby providing an additive common-path full-color display with only two neutral polarizers. Hybrid filters can be made using the CSLMs of this invention, in combination with other active or passive filters.

Abstract: An illumination system for a color projection display. In one embodiment a broad spectrum light source illuminates a multilevel optical phase element which disperses the broad spectrum light from the light source by diffraction. A display having a number of pixel elements, each capable of transmitting a predetermined spectral region, is positioned within the near field region of the multilevel optical phase element so as to receive the light dispersed by the multilevel phase element.

Abstract: Two of four light sources have canceling characteristics with respect to color nonuniformity, and the other two light sources have canceling characteristics with respect to color nonuniformity. A light emission stop detector detects that each of the light sources stops emitting light by blowing its bulb, for example, and feeds, if a certain light source stops emitting light, information indicating that the light source stops emitting light to an energization controller. The energization controller stops, when it receives the information indicating that a certain light source stops emitting light, the energization to a light source paired with the certain light source and puts out the light source.

Abstract: A single polarizer projector with a color switch and a projection method thereof, wherein the mean luminance of the inputted video signal is calculated so that the transmittance of the color switch can be controlled by the mean luminance in such a fashion that the transmittance is set to a maximum (100%) while setting the same to a low level (50%), thereby preventing unnatural blackening of relatively dark image for improving the contrast ratio.

Abstract: A pulse driven two lamp (40, 50) single light valve (62) imaging display system (10). The first lamp (40) is used to generate red light, and the second lamp (50) is used to generate blue and green light. A beam splitter (46) combines the white light of the two light sources, and directs the light to a color wheel (26). The first red lamp (40) is driven at a peak power being 3X the average power rating of the lamp for ⅓ of a video frame. The second blue-green lamp (50) is pulse driven at a peak power being 150% its average power rating for ⅔ of a video frame. The present invention achieves improved color balance and increased intensity, and is a simple and cost effective architecture.

Abstract: Light emitted from a white light source is separated into red, green and blue light beams by dichroic mirrors. The resulting light beams are directed onto a lenticular lens system having large-pitch lenticular lenses and small-pitch lenticular lenses formed on opposed surfaces. This lens system converts the red, green and blue light beams incident on each of the large-pitch lenticular lenses into a color band set consisting of a set of separated subbands of the red, green and blue light beams the diameter of which is narrowed down to one-third or less of that of the incident light beam through the small-pitch lenticular lenses. The resulting color band sets emerging from the small-pitch lenticular lenses are focused onto a DMD panel through a mirror galvanometer and a coupling lens. The mirror galvanometer is rotated in such a way as to move the color band sets over the DMD panel up and down by the amount corresponding to the pitch of the color band sets while the DMD panel is being driven.

Abstract: A projection display device wherein a modulated laser beam is scanned across a viewing surface by a system of rotating mirrors. A correcting mirror is provided for introducing small variations in the path of the beam. An instantaneous position of the beam on the viewing surface is monitored and a deviation between the actual pattern traversed by the beam and a predetermined scanning pattern is detected. The angular position of the correcting mirror is adjusted to reduce the deviation between the actual scanning pattern and the predetermined scanning pattern.

Abstract: A video display system includes a laser beam that is reflected from a vertical scan rotating mirror, then from a horizontal scan rotating mirror and then toward a viewing surface. The rotational angles of the mirrors and the intensity of the laser are controlled by a controller that is driven by a video signal. Rotation of the horizontal mirror scans the laser beam across the viewing surface while the laser intensity is modulated to form pixels on the viewing surface. The vertical scan mirror then directs the beam to the next horizontal scan line. The resolution and aspect ratio of the image are adjusted by changing the rotation rate of the mirrors and by changing the rate at which the laser is modulated.

Abstract: Disclosed is a ferroelectric liquid crystal display projector employing a fluorescent screen, including a light source emitting light of a predetermined wavelength; a first condensing lens for converting the light radiated from the light source into beams; a polarizing beam splitter for selecting a predetermined directional light in the incident light passing through the first condensing lens and for polarizing the light; a ferroelectric liquid crystal shutter on/off operated according to the polarizing operation of the polarizing beam splitter, the ferroelectric liquid crystal shutter comprising a reflecting layer attached on a backside and RAM devices attached on each pixel of a ferroelectric liquid crystal (FLC); an optical system for magnifying, at a predetermined ratio, the light reflected from the ferroelectric liquid crystal shutter; and a fluorescent screen of a fluorescent material which radiates by light, passing through the optical system, at a predetermined wavelength.

Abstract: In a process for generating at least three laser beams of different wavelengths for displaying color video pictures, a pulsed laser is used to generate light. The light output of the pulsed laser is released in a pulse and is introduced into a medium with nonlinear optical characteristics for generating a laser beam. In addition to the laser beam generated by excitation, this medium releases an additional laser beam whose frequency is given by the sum or difference frequencies of the exciting laser beam and the excited laser beam due to the nonlinear optical characteristics of the medium. The laser beams generated by the medium in this way and the exciting laser beam are used directly, or after frequency conversion, to display monochromatic partial images of a color video picture. An apparatus according to the invention contains suitable devices for carrying out the process.

Abstract: A method and apparatus for a single panel projector, for projecting images having a plurality of color components, include a mechanism for deflecting light into a plurality of directions, and a light panel for receiving the light deflected by the deflecting mechanism. The deflecting mechanism includes a transparent optical medium having a nonuniform thickness, in which light beams enter through a center opening of the medium and exit at areas along a side of the medium.

Abstract: A high definition image projector is provided for modulating light using an acousto-optic tunable filter according to image signals and projecting the modulated light on a screen. An image is obtained by modulating a light beam by pixel units according to the image to be displayed and directly projecting the modulated light beam on the screen in corresponding pixel units. High quality images can thus be displayed on a large screen. By adopting a high-output light source, a high luminance image can be obtained.

Abstract: A method of detecting and compensating for colors displayed by a display system (10) that uses a light source (16) and a color wheel (15). A desired color balance is specified in terms of a power ratio of three primary colors. This ratio is then compared to the actual power of light filtered through each color of the color wheel. (FIGS. 2A, 2B). In a first embodiment, the filter transmission characteristics are adjusted. (FIG. 3). In a second embodiment, the size of the color wheel's segments are changed as well as the display times for data corresponding to each segment. (FIG. 4). The two embodiments can also be combined to achieve a desired color balance.

Abstract: A color wheel assembly (15, 15a, 15b) for use in a display system (10) that uses a beam of source illumination to generate images with a display device. The color wheel (15) is moveable in and out of the path of the source beam so as to provide varying levels of brightness or color saturation. The color wheel (15') may also have concentric rings (41, 43) for varying saturation or color balance.

Abstract: A color display device (10) incorporates three light sources (12) supplying red, green and blue light respectively. A spatial light modulator (20) is positioned to provide time varying selective blocking of light from the sources (12) under television signal control. Light passes from the sources (12) to a condenser lens (16), then through a liquid crystal display element (22) and a projection lens (18) before reaching a screen (30). The display element (22) is also under television signal control. Signals supplied to the display element (22) provide for successive sets of three frames to be displayed, each set incorporating frame information to be displayed as red, green and blue and combinable to form a colored frame. When the element (22) displays a frame corresponding to one of the three colors red, green and blue, the modulator (20) transmits that color and blocks the others. The screen (30) receives a color image in which red, green and blue are displayed successively for each frame.

Abstract: A light valve such as an active matrix LCD between crossed polarizers, utilizing, for instance, individual transistors to control each "pixel area" of the LCD and storage elements to store video signal data for each pixel, with optically shielded "dead spaces" between pixels to eliminate electric field cross-talk and non-information-bearing light bleed-through, is illuminated with a bright independent light source which creates a video image projected via specialized projection optics onto an internal or external screen without distortions, regardless of the angle of projection onto the screen. Use of heat sinks, IR reflective coatings, heat absorbing optics, optional fluid and a thermistor controlled pixel transistor bias voltage injection servo circuit stabilizes image performance, maintaining accurate color and contrast levels as the LCD changes temperature.

Abstract: An electro-optical system such as an image display system and a method of displaying images are described. Laser beams of three primary colors are emitted from three lasers in a time sharing mode. These laser beams are directed onto the same optical path and then separately given optical information from the same optical modulating device in accordance with images of the respective primary colors. By this structure, displacement of constituent color images can be effectively avoided.

Abstract: A display device using laser comprises an input path for a composite video signal, a memory for storing the video signal by picture regions divided according to the size of picture, a controller for controlling the scanning position and the division of picture regions, a semiconductor laser for reading out R, G and B signals from the memory, and then scanning laser beams, and a scanning controller for controlling the path of a laser beam. The device displays an optical signal on a wall or large white surface without an additional cathode ray tube and adjusts screen size by controlling the distance between the device and the display surface.

Abstract: An image display apparatus is disclosed which includes: an optical system including a light source and at least one projection lens; a display means for forming a display image, the display means including a non-luminescent display panel and a microlens array disposed on the light-incidence side of the display panel; and at least one projection lens for projecting the display image; wherein the display panel and the microlens array are combined with each other by means of an adhesive made of a transparent material. In cases where the microlens array is provided with color filters which are arranged so as to correspond to the microlenses of this array, the image display apparatus can provide a bright display of color images with an improved contrast. Moreover, when the display panel and the microlens array are combined with each other by means of an adhesive containing spacers, the image display apparatus has a high thermal reliability.

Abstract: A tone correcting apparatus for an image display apparatus is disclosed. The apparatus includes a test signal generating circuit for generating a test signal, a memory for outputting tone correction data depending upon the test signal, a modulating circuit for modulating the light from a light source depending upon the tone correction data, a detecting circuit for detecting the modulated light from the modulated circuit, and a control circuit for calculating correction data depending upon a detected signal output from the detecting circuit. The correction data is stored in memory. Also disclosed is a laser display apparatus in which a laser beam is modulated according to a video signal before being displayed. An synchronizing separating circuit separates a synchronizing signal from the video signal. A selecting circuit selects between a test signal generated by a test signal generating circuit and the video signal depending upon the synchronization signal.

Abstract: This invention uses various solid-state semiconductor lasers along with frequency doublers as needed to achieve the required three-color light beam wavelengths for input to available light combiners and to a state-of-the-art scanner. The scanner projects a color laser beam to a screen or other equipment. A number of alternate solid-state laser means are described, each combination providing the required light output. Use of the described solid-state lasers instead of the commonly used gas lasers results in considerable savings in required electrical power, cooling and system size.

Abstract: An improved, multicolored video imaging system to provide a video image on a projection surface, which system includes a red, blue and green pulsed laser as a light source to provide inlet beams, an acoustic-optical cell to receive the inlet beams, an electrical signal to a sound transducer on the cell to provide a sound-modulated outlet beam; a projection surface to display the multicolored image and a projection system to project the outlet beam onto the projection surface to display the video image. The system includes as an improvement a solid state actuator to move a distance in a 45.degree. direction to backtrack the line of image of the outlet beam and a ramp signal device to provide a ramp signal that is proportional in time to the pulse duration of the input beams when the pulse duration is longer than the pixel propagation time for a line of image to be displayed, thereby minimizing the blurring of the line of image displayed.

Abstract: A display device of projection type capable of projecting an image with well defined image frame is disclosed. The device comprises 3 spatial light modulators on which color image information is written in 3 primary colors respectively and is read out as a combined optical color image in a form of light beam, the light beam is then projected out of the display device through lens groups for forming a projected image on a screen, the device further comprises a mask disposed in a proximity of an imaginary image formation plane arranged to locate in a vicinity of one of the lens groups, the light beam is caused to form an optical image on the imaginary image formation plane. The mask has a variable light shielding configuration controlled either electronically or electro-mechanically for cutting off unnecessary light portions of the light beam carrying the optical image so that an image of high contrast and well defined clear fringe is projected on the screen.