An optical system is described consisting of reflection birefringent light valves, polarizing beam splitter, color image combining prisms, illumination system, projection lens, filters for color and contrast control, and screen placed in a configuration offering advantages for a high resolution color display. The system includes a quarter wave plate positioned to suppress stray reflection from the projection lens. The system also includes a second quarter wave plate disposed on the screen and a polarizing film disposed on the second quarter wave plate to suppress ambient light from illuminating the screen and entering the system.

Efficient optical system for a high resolution projection display employing reflection light valves

A device, system and a method for displaying image data of a plurality of colors, the device comprising a light source (50) for producing light having at least four primary colors, a controller (56, 58) for determining a combination of at least four primary colors according to the image data (72) for production by the light source and a viewing screen (60) for displaying the image data the combination from the controller. The present invention is not limited to combinations of colors which are produced from only three primary colors, such as red, green and blue.

Device, system and method for electronic true color display

An optical display system includes a light source, a color wheel, an optical train and a light valve. The optical train includes a diffuser element, a compound parabolic concentrator and an integrator. The diffuser element diffuses incoming light to fill in holes in cone half-angle distribution of light generated by the light source. The compound parabolic concentrator reduces the cone half-angle of the diffused light to a cone half-angle expected by the light valve. The integrator reduces hot spots in the diffused light. The color wheel may modulate optical path length of light traveling through the color wheel. Modulating the optical path length reduces coherence in the light generated by the light source. A color wheel that reduces coherence would allow the light source to be laser or LED-based. If the light valve is a ferroelectric light valve, the color wheel may include pairs of polarizers. Light is polarized in orthogonal directions by the polarizers in a pair. This allows all of the light to be used by the ferroelectric light valve during dc balancing.

Optical display system including a light valve

An apparatus and method of printing two-dimensional swaths of area onto a photosensitive media uses at least one reflective liquid crystal spatial light modulator. In the apparatus and method, illumination optics receive light from a light source and image the light at a polarization beamsplitter element. The polarization beamsplitter element images one polarization state of light at the spatial light modulator to create an essentially telecentric illumination at the spatial light modulator.

Reflective liquid crystal modulator based printing system

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 colours to produce colour sequential illumination of the light valve In addition to filter wheels producing sequences of red, blue, green illumination, including the possibility of splitting a colour phase into non-adjacent smaller phases to reduce colour artifacts, a simple filter wheel which in two rotations produces a sequence of red, blue, green, cyan, magenta, yellow colour illumination, resulting in an expanded colour gamut, is also disclosed Blanking intervals during which both lamps are turned off span each passage of a segment boundary through the spot

Two lamp, single light valve projection system

A liquid crystal display apparatus which includes: a light-addressed liquid crystal light valve including a photoconductive layer and a liquid crystal layer between a pair of light transmitting substrates, each of the light transmitting substrates having an electrode for applying a voltage across the photoconductive layer and the liquid crystal layer; a writing unit for writing an image of a display medium in the light-addressed liquid crystal light valve with writing light from the display medium through a writing lens; a projecting unit for projecting the image written in the light-addressed liquid crystal light valve by irradiating reading light from a projection light source to the light-addressed liquid crystal light valve; and a controlling unit for controlling at least one of operational characteristics of the light-addressed liquid crystal light valve and a luminance of the writing light in accordance with a luminance of the display medium, is disclosed.

Liquid crystal projector using a spatial light modulator and two rotating color filters

An image display device is arranged to have a liquid crystal light valve, a liquid crystal display panel, a backlighting unit, and a rod lens array. The liquid crystal light valve serves to form an image from the light applied thereto. The liquid crystal display panel serves to form a light pattern to be written to the liquid crystal light valve. The backlighting unit serves to apply light to the panel. The rod lens array is located between the liquid crystal panel and the liquid crystal light valve so that each of the light acceptance angle θ (half angle) and the degree of parallelization α (half angle) of light are not less than tan -1 {P/(3 1/2 ·L)} (P is a pitch and L is a distance between the incident end of light and the pixel of the matrix type liquid crystal display panel) and at least one of the light acceptance angle θ (half angle) and the degree of parallelization a of light is 20° or less.

Akitsugu Hatano

Papers

Liquid crystal projector using a spatial light modulator and two rotating color filters

Projection type image display device maintaining resolution of an image unaffected by parallax