Abstract: This invention is related to a thin film transistor (TFT) array and method of making same, for use in an active matrix liquid crystal display (AMLCD) having a high pixel aperture ratio. The TFT array and corresponding display are made by forming the TFTs and corresponding address lines on a substrate, coating the address lines and TFTs with a photo-imageable insulating layer which acts as a negative resist, exposing portions of the insulating layer with UV light which are to remain on the substrate, removing non-exposed areas of the insulating layer so as to form contact vias, and depositing pixel electrodes on the substrate over the insulating layer so that the pixel electrodes contact respective TFT source electrodes through the contact vias. The resulting display has an increased pixel aperture ratio because the pixel electrodes are formed over the insulating layer so as to overlap portions of the array address lines.

Abstract: 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 nx>ny>nz 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.

Abstract: A system and method for driving a thin film diode (TFD) inclusive AMLCD or imaging device (e.g. x-ray imager) includes providing each pixel with a pair of select lines and a single data line. Drive schemes are provided which increase the circuits tolerance for spacial and temporal variations in diode (e.g. MIM diode) characteristics, improve response time, increase the circuit's tolerance for RC delays on data lines, and reduces the potential for crosstalk or image retention. In certain embodiments, where each pixel includes a pair of select lines, and a single data line, the select voltage on the first select line alternates between VS+Voffset and VS−Voffset for subsequent frames, while the select voltage on the other select line alternates between −VS+Voffset and −VS−Voffset for subsequent frames, thereby allowing voltage at the common node to be added to the data voltage.

Abstract: A method of manufacturing a PIN (positive-intrinsic-negative) diode structure includes depositing an insulation or dielectric layer over the bottom PIN diode electrodes, prior to depositing the PIN semiconductor layers. The insulation layer results in a PIN diode structure with reduced leakage current, reduced RIE (reactive ion etching) chamber contamination, the reduction or elimination of post RIE processing, improved yields, and/or expands the potential materials that may be used for the bottom electrode. A corresponding PIN diode structure is also disclosed. The resulting PIN diode structures may be used in, for example, LCD (liquid crystal display) and solid state imager applications.

Abstract: 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°-20°, most preferably from about 6°-10° 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.

Abstract: 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°-20°, most preferably from about 6°-10° 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.

Abstract: A system and method for driving a thin film diode (TFD) inclusive AMLCD or imaging device includes providing each pixel with a pair of select lines and a single data line. In certain embodiments, the insulator or semi-insulator layer between electrodes of the diode includes, or is of, amorphous carbon nitride alloy. In other embodiments, the semi-insulating layer includes polycrystalline carbon or nanocrystalline carbon.

Abstract: A TFT structure includes a variably doped contact layer system in order to reduce leakage current characteristics and increase mobility of the TFT. Such TFTs may be utilized in, for example, X-ray imagers or liquid crystal displays. In certain embodiments, the contact layer system is lightly doped adjacent a semiconductor or channel layer, and is more heavily doped adjacent the source/drain electrodes. The variation in doping density of the contact layer system may be performed in a step-like manner, gradually, continuously, or in any other suitable manner. In certain embodiments, the contact layer system may include a single layer which is deposited over an intrinsic semiconductor layer, with the amount of dopant gas being used during the deposition process being adjusted through the deposition of the single layer so as to cause the doping density to vary (increase or decrease) throughout the thickness of the system/layer.

Abstract: A method of manufacturing a PIN (positive-intrinsic-negative) diode structure includes depositing an insulation or dielectric layer over the bottom PIN diode electrodes, prior to depositing the PIN semiconductor layers. The insulation layer results in a PIN diode structure with reduced leakage current, reduced RIE (reactive ion etching) chamber contamination, the reduction or elimination of post RIE processing, improved yields, and/or expands the potential materials that may be used for the bottom electrode. A corresponding PIN diode structure is also disclosed. The resulting PIN diode structures may be used in, for example, LCD (liquid crystal display) and solid state imager applications.

Abstract: 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.

Abstract: A liquid crystal display (LCD) includes a multilayer black matrix system for improving the contrast of displayed images. The black matrix system includes at least one layer of a material that has variable amounts of chemical elements. By, for example, varying "x" and "y" in SiO.sub.x N.sub.y, the refractive index "n" of adjacent SiO.sub.x N.sub.y layers can be slowly varied through the thickness of the system so that the refractive index adjacent the substrate substantially matches that of the substrate and so that there are no overly large refractive index differences between adjacent layers in the system. This reduces light reflections off of the black matrix system.

Abstract: This invention is related to a radiation imager (e.g. x-ray imager) and method of making same. An insulating material having a low dielectric constant is provided in areas of overlap between collector electrodes and underlying TFTs, diodes, and/or address lines in order to improve the signal-to-noise ratio of the imager. The TFT array and corresponding imager are made in certain embodiments by coating the address lines and TFTs with a photo-imageable insulating layer which acts as a negative resist, exposing portions of the insulating layer with UV light, removing non-exposed areas of the insulating layer so as to form contact vias, and depositing storage capacitor collecting electrodes over the insulating layer so that the collecting electrodes contact TFT source electrodes through the contact vias. The resulting imager has an improved signal-to-noise ratio due to the low dielectric constant of the insulating layer.

Abstract: A liquid crystal display includes at least one polarizer located interior or internally of substrates of the display. In certain embodiments, the polarizer may be spin-coated onto the interior of one of the substrates, preferably the passive substrate of the display. Such a polarizer may also be located interior of color filters on the copassive substrate. Thus, light being transmitted through the display proceeds through the front polarizer prior to being de-polarized by the color filters. The result is improved contrast ratios in the display due to the minimization of the de-polarizing of color filters. In certain embodiments, the internal polarizer(s) may be photo-patternable by way of ultraviolet photo-imaging.

Abstract: 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.

Abstract: This invention is related to a radiation image (e.g. X-ray imager) including a thin film transistor (TFT) array, and method of making same. A photo-imageable interface barrier layer is provided between an array of collector electrodes and a photoconductor layer so as to simplify the process for manufacturing the imager and to improve image uniformity. In certain embodiments, the barrier layer is a negative resist. In certain embodiments, the barrier layer and an insulating layer over the TFTs may be of the same photo-imageable material.

Abstract: 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.

Abstract: 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 defined by n.sub.x =n.sub.y >n.sub.z where the "z" direction is substantially perpendicular to the film plane and the "x" and "y" directions are substantially parallel to the film plane. According to certain embodiments, a pair of positive and a pair of negative retardation films are provided such that the two positive retarders sandwich both the liquid crystal layer and the negative retarders therebetween. By providing the positive and negative retarders with specific retardation values and/or ratios, improved viewing characteristics are provided.

Abstract: This invention is related to a radiation imager (e.g. X-ray imager) including a thin film transistor (TFT) array, and method of making same. A photo-imageable insulating material having a low dielectric constant is provided in areas of overlap between electrodes and underlying TFTs, diodes, and/or address lines in order to improve the signal-to-noise ratio of the imager. The photo-imageable insulating layer acts as a negative resist in certain embodiments, so that vias are formed therein by exposing portions of the insulating layer with UV light which are to remain on the substrate, removing non-exposed areas of the insulating layer so as to form the vias or apertures in the insulating layer. In order to prevent non-uniformities from inadvertently being imaged into the photo-imageable insulating layer, an ultraviolet (UV) blocking/absorbing layer is provided.

Abstract: This invention is related to an active matrix liquid crystal display (AMLCD) or an X-ray imaging device having a high aperture ratio. The imager or display has an increased aperture ratio because electrodes are formed over dual insulating layers so as to overlap portions of the array address lines and/or TFTs. Both the manufacturability and capacitive crosstalk of the device are improved due to the use of a photo-imageable organic insulating layer between the pixel electrodes and the address lines. An intermediate inorganic insulating layer is provided between the photo-imageable organic insulating layer and the overlapped TFTs in order to prevent the organic insulating layer from directly contacting semiconductor material in the TFTs thereby reducing potential voltage swings.

Abstract: A backlit transmissive liquid crystal display including non-linear resistive thin film diodes (TFDs). Select address lines on the active substrate provide both conventional address line functionality, as well as acting as one of the electrodes for each thin film diode. Two such diodes are provided in each pixel in certain embodiments. Still further, black matrix material is provided between the aforesaid address line material and the substrate so as to form rows of stacks on the active substrate. The thin film diode semi-insulating material, the address line material, and the black matrix material are patterned together in a single step to form elongated rows (or columns) on the active substrate. In such a manner, the display has reduced ambient light reflections, and reduce photosensitivity.