Abstract: The present invention relates to a method of generating an image having a desired brightness, which image is generated by means of a device provided with at least one light source, at least one electro-optical light modulation panel and at least one light-control device. The light from the light source is converted into an image having a desired brightness via at least the electro-optical light modulation panel and the light-control device. The image to be projected is analyzed in a regulator, whereafter the electro-optical light modulation panel and the light-control device are driven, while a too bright image is generated by means of the electro-optical light modulation panel, which image is converted by means of the light-control device into an image having a desired brightness and a desired contrast.

Abstract: A method of reducing the artifact in color sequential LCD projection systems while providing flicker free and stable lamp operation. The method consists of establishing the frequency of lamp pulsing at a rate in response to the display frame rate. A further refinement is achieved by alternating a sequence of intervals of enhanced brightness with a sequence of low lamp current levels in successive frames to minimize spatial modulation.

Abstract: A head-mounted projection display system is characterized by a pair of head-mounted low-power image projectors mounted adjacent the eyes of the viewer, and aimed to project in a direction along the line of sight of the viewer toward a high-gain, retro-reflective screen. Stereoscopic viewing is enabled by projecting separate images to the right and left projectors. The retro-reflectivity of the screen ensures that the right and left images will be returned to the right and left eye, respectively.

Abstract: A method and apparatus for introducing alterations in video screen images includes projecting recordable but not viewer visible, colored bars, stripes or the like into the video screen images using randomly selected scanning sequences and/or scanning rates, each of which are selected when a known event, such as a known period of time or change in the content of the video screen images, occur.

Abstract: A solid state multi-spectral light source for a multi-spectral light source system includes an array of LED groups, wherein each LED group may include red, green, and blue LEDs. The LEDs produce color light bars by activating the appropriate color LEDs. The color light bars can be flashed or scrolled to integrate a color display.

Abstract: Methods for simulating 3D video images using 2D video input are disclosed. The methods may include detecting a direction of a majority of spatial movement of the 2D video input, separating the 2D video input into left and right signals, and delay processing either the left or right signal based on the detected direction of the majority of spatial movement. The method may also include simultaneously displaying the left signal to the viewer's left eye and the right signal to the viewer's right eye after the delay processing.

Abstract: The present invention relates to a method of generating an image having a desired brightness, which image is generated by means of a device provided with at least one light source, at least one electro-optical light modulation panel and at least one light-control device. The light from the light source is converted into an image having a desired brightness via at least the electro-optical light modulation panel and the light-control device. The image to be projected is analyzed in a regulator, whereafter the electro-optical light modulation panel and the light-control device are driven, while a too bright image is generated by means of the electro-optical light modulation panel, which image is converted by means of the light-control device into an image having a desired brightness and a desired contrast.

Abstract: A head-mounted projection display system is characterized by a pair of head-mounted low-power image projectors mounted adjacent the eyes of the viewer, and aimed to project in a direction along the line of sight of the viewer toward a high-gain, retro-reflective screen. Stereoscopic viewing is enabled by projecting separate images to the right and left projectors. The retro-reflectivity of the screen ensures that the right and left images will be returned to the right and left eye, respectively.

Abstract: A method and device for preventing video tape piracy of video material shown by an electronic projector by varying frequently the frame rate, line rate or pixel rate of the projector. In a preferred embodiment the frame rate is varied in accordance with a cryptographically secure algorithm. In another embodiment the frame rate is varied in accordance with the content of the scene in the film.

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 head-mounted projection display system is characterized by a pair of head-mounted low-power image projectors mounted adjacent the eyes of the viewer, and aimed to project in a direction along the line of sight of the viewer toward a high-gain, retro-reflective screen. Stereoscopic viewing is enabled by projecting separate images to the right and left projectors. The retro-reflectivity of the screen ensures that the right and left images will be returned to the right and left eye, respectively.

Abstract: A method for operating a lamp which includes the steps of providing an electric lamp having a pair of electrodes and an arc gap therebetween, providing a power supply for applying a voltage and current to the electric lamp, and providing a controller for sensing lamp parameters and configured to control a signal to be applied by the power supply to the electric lamp. The method further includes sensing the parameters of lamp operation. The sensed parameters are compared with desired lamp parameters. The controller commands the power supply to add a current pulse to a specific portion of the lamp current.

Abstract: A dual lamp illumination system, in which the output beams of two lamps with collimating reflectors are directed into one another to produce a combined beam, and in which plane mirrors set at 90 degrees to one another are inserted half way into the combined beam. Thus half of the combined beam is directed out of the path of the combined beam to form a new combined beam having substantially the same etendue as the original combined beam. The the light rays in the unreflected half of the original combined beam are recycled until they strike one of the plane surfaces, and are thence reflected out into the new combined beam.

Abstract: A projection system includes first and second light sources which are disposed at an angle with respect to each other and are activated during respective different phases of an illumination cycle to illuminate a spot on different sides of a segmented rotary filter wheel. The filter wheel is alternately used to transmit light from one of the light sources, and to reflect light from the other light source, to a light valve, the output of which is projected onto a screen. The wheel segments may be alternately clear and mirrored or may alternately transmit and reflect colors to produce color sequential illumination of the light valve. In addition to filter wheels producing sequences of red, blue, green illumination, including the possibility of splitting a color phase into non-adjacent smaller phases to reduce color artifacts, a simple filter wheel which in two rotations produces a sequence of red, blue, green, cyan, magenta, yellow color illumination, resulting in an expanded color gamut, is also disclosed.

Abstract: A color control system for projection television displays having a projection lamp, a light valve and a device for varying the color of the light from the projection lamp, such as a color wheel. The color wheel driver provides an output signal which represents the position, that is the color, of the color wheel disposed in the lamp beam. The lamp driver varies the output power used to drive the lamp in response to the particular color of the color wheel disposed in the beam. If the projection lamp has a deficiency in a certain color the present system provides greater output power to the projection lamp during the presence of the filter for that color. A user input control provides for changing the tint of the system based on user preferences and/or any changes occurring in the color filters or projection lamp.

Abstract: A color correction system for a video projection system utilizing a single light valve for modulating light impinging thereon with a video signal and three projection lamps, one for each of the primary colors, which are activated sequentially. Positioned in the light path between two of the lamps and the light valve are occluders which block and unblock the light output from their associated lamp. The lamps which have the occluders are operated such that each lamp may be driven with a series of non-occluded pulses and occluded pulses. The occluded pulses occur when the occluder blocks the light output from the lamp. The more a desired reduction in light output in one of the colors is required, the non-occluded pulses are reduced and the corresponding occluded pulses are increased. This permits adjustment of the colorimetry of the system without adversely affecting the electrical properties of the lamp.

Abstract: A three dimensional projection television system in which the screen of the receiver alternatively receives a television picture field as polarized by polarizing apparatus and a television picture field which is orthogonally polarized with respect to the fields polarized by the polarizing apparatus. Also disclosed in a receiver for use in such a system. The receiver includes three projectors each projecting through a polarizer and an individual electro-optical crystal device.

Abstract: A blackened optical system includes a transparent substrate having a front side provided with at least a pair of elongate ribs forming therebetween an elongate groove. An amount of optically black discrete particles for absorbing visible ambient light is disposed in the groove. The particle amount is contained within the groove by means of a skin which extends between the ribs and over the groove.