Honeywell G.m.b.h.

Litton Systems, Inc.

J Michael Lengyel

Ronald C Robinder

Larry A Nelson

Randy M Maner

Loy L Spears

James B Armstrong

A daylight readable LCD which may be used to communicate information as high contrast images (static or dynamic, color or monochrome) in bright ambient lighting conditions over a wide temperature range in direct sunlight. A contrast enhancement filter assembly is disposed at the interface between a backlit display and a user. The contrast enhancement filter assembly includes a triple bandpass contrast enhancement filter that preferably passes light efficiently in each of the red, green, and blue primary wavelengths and substantially absorbs all other wavelengths. Display contrast is increased because of the absorption of incident light having wavelengths that differ from the light produced by the internal backlight source within the display. This results in the display having a blacker background and enhanced purity of the color primaries. The display element is disposed generally behind the contrast enhancement filter assembly. An air gap separation is preferably provided between the contrast enhancement filter assembly and the display element to allow a heat conducting medium to flow therebetween to control thermal loading of the display. A fluorescent backlight assembly provides at least about 5,000 fL of illumination. An air gap separation is preferably provided between the display element and the backlight to allow a heat conducting medium to flow therebetween to control thermal loading of the display. The ratio of output light to reflected incident ambient light is at least about 5:1.

Daylight readable liquid crystal display

A phosphor binding material and process is shown and described for LCD backlight systems. The improved process provides a residual phosphor binding material transparent to UV light. No UV light energy is lost to absorption in the binding material and more UV light energy is used to produce visible light. Because the UV light is better utilized in the production of visible light, overall lamp efficiency is improved.

Method for producing phospher binding materials

A backlight assembly for liquid crystal displays uses a clear sheet of plastic or UV friendly resin as a light-pipe and has one or more fluorescent lamps located in a cavity along an edge of the sheet. The cavity is coated with photo-luminescent phosphor. A quartz ultra-violet lamp inside the cavity is filled with Argon gas and a small amount of mercury to excite the phosphor coated cavity to fluoresce. The light energy generated is throughout the light-pipe, thereby providing much brighter displays than possible with prior art light-pipe backlight assemblies.

Backlight with integral illumination source

A fluorescent cavity backlight system that provides a high efficiency light source suitable for rear illumination of transmissive electronic display devices. The inventive fluorescent cavity backlight system can be adapted to a wide variety of flat panel display applications. The invention takes a complete system approach towards designing a high efficiency backlight source. The backlight system comprises three major subassemblies: a phosphor illuminator, a fluorescent cavity, and improved control/driver electronics. Each of the subassemblies has been optimized internally, and with respect to each of the other subassemblies.

High efficiency backlighting system for rear illumination of electronic

Ultraviolet binder for phosphor fluorescent light box

A photographic facsimile of a line image at a predetermined orientation is illuminated by a collimated monochromatic light source to produce a diffraction pattern. The diffraction pattern is focussed by a converging lens to image the Fourier transform of the line image on a spatial frequency plane. The image in the spatial frequency plane is applied to a detector for measuring the spatial power distribution as a function of the spatial frequency. The line image is then reoriented in the image plane, and successive measurements made as the image is rotated in the image plane. Resolution is quantified in the spatial frequency plane as the magnitude of a selected signal as a function of displacement (i.e, spatial frequency). By simulating selected imaging components and generating a resultant line image, the resolution of any imaging system component may be measured.

Method and apparatus for measurement of resolution of imaging systems

A prismatic refracting array for a flat panel liquid crystal display (LCD) backlighting device matches a prismatic angle with the critical angle of the exit window and surrounding material, e.g., glass and air. By selecting the prism angle of the refracting array with reference to the critical angle of the exit window and surrounding air, light lost to total internal reflectance within the exit window is substantially eliminated while directing all light output within selected view angles. By better utilizing the available light output from the flat panel backlight device, overall efficiency of the LCD device is improved.

Prismatic refracting optical array for liquid flat panel crystal display

A photographic facsimile of a line image at a predetermined orientation is illuminated by a collimated monochromatic light source to produce a diffraction pattern. The Fourier distribution of the diffraction pattern is focussed by a converging lens to image on a spatial frequency plane of spatial signal and spatial noise components. The image in the spatial frequency plane is applied to a detector for selectively measuring the spatial power contribution of the signal and noise components, thereby to provide a measure of image quality relating to imaging system signal-to-noise ratio. A spatial filter (18) may be introduced into the optical path to block the spatial signal components, while allowing the noise components to impinge on the detector. The line image is then reoriented in the image plane, and successive measurements of spatial signal and noise contributions repeated. The ratio of signal-to-noise power is then computed for each orientation of the line image. By simulating selected imaging components and generating a resultant line image, the effect of such components on noise may be determined.

Method and apparatus for measurement of spatial signal and noise power

Fluorescent lamp energy efficiency is improved by providing geometric formations on the surface to which the phosphor coating is applied. By such geometric formations, a greater oblique surface area is available for receiving a desirably thin phosphor coating such that greater and more uniform visible light output is obtained from the device for a given energy input, i.e., greater relative to that possible with smooth surfaces receiving the phosphor coating. In the illustrated embodiment, the interior surfaces of an enclosure include V-shaped groove formations for increasing the interior surface area and establishing oblique orientation relative to approaching UV light rays. A UV light source is placed within the enclosure for excitation of a phosphor coating applied to the interior surfaces of the enclosure. The invention is particularly well adapted for use as a backlighting system in an active matrix liquid crystal display device.

High efficiency fluorescent lamp device

An apparatus for achieving an active matrix liquid crystal display flat panel that optically eliminates bluish or purplish background luminance and fluorescence of the liquid crystal materials. Two polarized layers are placed in a crossed configuration one behind and one in front of an active glass thin film transistor (TFT) layer to block a majority of any background luminance. Two layers of tinted glass are further placed one behind and one in front of the active glass TFT layer to block any remaining background luminance which has leaked through the polarizing layers.

Growing community of inventors

Ramona, CA, United States of America

J Michael Lengyel