Ois Optical Imaging Systems, Inc.

Adiel Abileah

Gang Xu

Patrick F Brinkley

John Z Zhong

John A Vanderploeg

Charles Sherman

Nicholas David Vergith

John VanDerploeg

Robert M Cammarata

A normally white twisted nematic liquid crystal display is provided for outputting improved viewing characteristics which are defined by high contrast ratios and reduced inversion. The display includes both positive and negative retardation films, the negative films being biaxial and defined by n,>n,>n,in certain embodiments where the &ldquo;z&rdquo; direction is substantially perpendicular to the film plane and the &ldquo;x&rdquo; and &ldquo;y&rdquo; directions are substantially parallel to the film plane. By providing the positive and biaxial negative retarders with specific retardation values and/or ratios, improved viewing characteristics are provided. According to other embodiments, a positive and a negative (uniaxial or biaxial) retarder may be provided on only one side of the liquid crystal layer.

Normally white twisted nematic LCD with positive uniaxial and negative biaxial retarders

A normally white liquid crystal display is provided with a positively birefringent uniaxial retardation film having a retardation value of from about 100-200 nm. The retardation film is provided on one side of the liquid crystal layer, the liquid crystal being sandwiched between a pair of orientation or buffing films which orient the liquid crystal molecules adjacent thereto in predetermined directions. The optical axis of the retardation film is rotated from about 2&deg;-20&deg;, most preferably from about 6&deg;-10&deg; relative to the buffing direction on the opposite side of the liquid crystal layer. This rotation of the retardation film optical axis allows for the high contrast ratio viewing zone of the display to be shifted vertically into either the positive or negative vertical viewing region depending upon the direction of rotation of the retardation film optical axis. Alternatively, biaxial retardation films having similar retardation values may be utilizied according to the teachings of this invention.

Normally white LCD including first and second biaxial retarders

Liquid crystal display having high contrast viewing zone centered in positive or negative vertical region

A multi-colored pixel for a twisted nematic liquid crystal display including red, green, and blue subpixels, wherein each subpixel includes a pair of substrates, a pair of polarizers, opposing electrodes, and a color personalized retardation film which compensates for the different wavelength of each color. The personalized retardation films of the different color subpixels results in elimination of the multi-gap approach and substantially eliminates the problem of different color leakages at different viewing angles, including normal. Also, one polymer based element, preferably a polyimide, functions as both a color filter and a retardation film in certain embodiments of this invention.

Liquid crystal display with optical compensator

A backlit liquid crystal display device having improved nighttime operational characteristics includes a fluorescent lamp for daytime operation and a separate light source for nighttime operation which emits a low-intensity light. Preferably, the nighttime light source is an electroluminescent panel which also acts as a daytime reflector of light. An integral image-splitting and collimating lens is provided to increase the uniformity of the light emitted and to provide wide angle viewability. A sharp cut-off IR filter may also be included in the device to provide NVIS-B night vision goggle compatibility.

Day/night backlight for a liquid crystal display

A liquid crystal display in which a negatively birefringent layer is used as both an orientation film and as a retarder in the display. An improved method of making such a display is also disclosed. In preferred embodiments, each of the orientation layers has a retardation value of from about -80 to -200 nm.

Normally white twisted nematic liquid crystal display including

A normally white twisted nematic liquid crystal display is provided for outputting improved viewing characteristics which are defined by high contrast ratios and reduced inversion. The display includes both positive and negative retardation films, the negative films being biaxial and defined by n.sub.x &gt;n.sub.y &gt;n.sub.z in certain embodiments where the 'z' direction is substantially perpendicular to the film plane and the 'x' and 'y' directions are substantially parallel to the film plane. By providing the positive and biaxial negative retarders with specific retardation values and/or ratios, improved viewing characteristics are provided. According to other embodiments, a positive and a negative (uniaxial or biaxial) retarder may be provided on only one side of the liquid crystal layer.

Normally white twisted nematic LCD with positive uniaxial and nebative

Liquid crystal display with patterned retardation films

A notch filter is provided in a RGB color twisted nematic liquid crystal display (LCD) apparatus, the notch filter preferably being located between the light source and the display panel. Undesirable peak(s) (e.g. blue-green) in the light rays from the source are substantially reduced or eliminated by the notch filter thereby improving the color saturation characteristics of the image reaching the viewer.

LCD with notch filter

A normally white liquid crystal display is provided with a positively birefringent uniaxial retardation film having a retardation value of from about 100-200 nm. The retardation film is provided on one side of the liquid crystal layer, the liquid crystal being sandwiched between a pair of orientation or buffing films which orient the liquid crystal molecules adjacent thereto in predetermined directions. The optical axis of the retardation film is rotated from about 2.degree.-20.degree., most preferably from about 6.degree.-10.degree. relative to the buffing direction on the opposite side of the liquid crystal layer. This rotation of the retardation film optical axis allows for the high contrast ratio viewing zone of the display to be shifted vertically into either the positive or negative vertical viewing region depending upon the direction of rotation of the retardation film optical axis. Alternatively, biaxial retardation films having similar retardation values may be utilizied according to the teachings of this invention.

Liquid crystal display having high contrast viewing zone centered in

A liquid crystal display and corresponding method are provided for reducing display image reflections off of a reflection point on an external medium (e.g. cockpit canopy or automotive windshield). A retarder is provided on the front side of the display so that the polarization direction of the display image is substantially parallel to the plane of incidence when the image reaches the reflection point. Additionally, the angle of incidence .THETA..sub.i is substantially matched to the Brewster angle .THETA..sub.p in order to maximize the reduction of reflection at the reflection point. The retarder has a retardation value of from about 220-320 nm according to certain embodiments, and is a 1/2 .lambda. retarder according to preferred embodiments.

LCD with reduced canopy reflection

A normally white twisted birefringent liquid crystal display having first and second retardation films having retardation values of about 80-200 nm on opposite sides of a liquid crystal layer for the purpose of expanding the viewing angles of the display. Also, the viewing zone of this normally white display can be shifted vertically by rotating the optical axes of the retardation films so as to position the viewing zone away from an inversion area.

Method of making and using a normally white twisted nematic LCD with

LCD including a negative biaxial retarder on each side of the liquid

A backlight liquid crystal display including a collimated backlight for illuminating a display panel having a liquid crystal layer sandwiched between rear and front polarizers, the panel including an optical refracting film and a diffuser laminated adjacent the front surface of the panel. The refracting film and light scattering diffuser may be either exterior or interior the front polarizer, but on the viewer side of the liquid crystal layer. The optical system of the refracting faceted film along with the diffuser maintains the resolution of the display, improves the contrast ratio over a wide range of viewing angles, reduces its ambient light reflectively, reduces color shifting, substantially eliminates inversion, and enlarges the effective viewing zone of the display.

Growing community of inventors

Farmington Hills, MI, United States of America

Adiel Abileah