Abstract: Reversible electrochemical mirror (REM) devices typically comprise a conductive oxide mirror electrode that is substantially transparent to radiation of some wavelengths, a counter electrode that may also be substantially transparent, and an electrolyte that contains ions of an electrodepositable metal. A voltage applied between the two electrodes causes electrodeposition of a mirror deposit on the mirror electrode and dissolution of the mirror deposit on the counter electrode, and these processes are reversed when the polarity of the applied voltage is changed. Such REM devices provide precise control over the reflection and transmission of radiation and can be used for a variety of applications, including smart windows and automatically adjusting automotive mirrors. According to the present invention, measurements of the sheet resistance of the mirror electrode in a REM device are correlated with the thickness of electrodeposited mirror metal and can be used to monitor the reflectance of the device.

Abstract: Electrochemical surface analysis using a deoxygenated gel electrolyte provides advantages over a liquid electrolyte in processes such as sequential electrochemical reduction analysis. In sequential electrochemical reduction analysis, a solderable portion of an electronic component or circuit board to be tested is placed in contact with a deoxygenated gel electrolyte such as a borate buffer solution having a gelling agent. The gel electrolyte prevents capillary attraction up or along a lead of the component so that the power source cathode lead does not contact the electrolyte and electrochemical analysis can be localized to the area of interest, such as the portion of the component lead to be soldered. Interfering effects of atmospheric oxygen are minimized for deaerated gel electrolytes because convection mixing is practically absent and diffusion is generally a very slow process in a gel.

Abstract: An electrochemical mirror includes a transparent first electrode and a second electrode. An electrolytic solution, disposed between the first and second electrodes, contains ions of a metal which can electrodeposit on the electrodes. A negative electrical potential applied to the first electrode causes deposited metal to be dissolved from the second electrode into the electrolytic solution and to be electrodeposited from the solution onto the first electrode, thereby affecting the reflectivity of the mirror for electromagnetic radiation. A surface modification layer applied to the first electrode ensures that the electrodeposit is substantially uniform, resulting in a mirror layer which increases the reflectivity of the mirror. A positive electrical potential applied to the first electrode causes deposited metal to be dissolved from the first electrode and electrodeposited from the solution onto the second electrode, thereby decreasing the reflectivity of the mirror.

Abstract: An O-plate compensator comprising an organic liquid crystal polymer, and methods for fabricating the same, are disclosed. The compensator is a uniaxial birefringent thin film with its extraordinary axis oriented obliquely with respect to the surface of the film. (It is noted that the birefringent thin film could be weakly biaxial.) The oblique orientation of the liquid crystal director, which is parallel to the film's extraordinary axis, is achieved by casting an organic thin film onto a surface specially prepared for orienting liquid crystals, such as obliquely deposited SiO, mechanically rubbed alignment agents. The film can either be cast from a solution of the liquid crystal polymer or from a reactive liquid crystal monomer having a nematic phase. Any solvent that may be used during the fabrication process is evaporated off and the organic thin film is held at a temperature in its nematic phase. If a reactive monomer is used, the film is then photopolymerized.

Abstract: A normally white liquid crystal display includes polarizer and analyzer layers having perpendicular absorbing axes. A liquid crystal layer is disposed between the polarizer layer and the analyzer layer, with its director exhibiting an azimuthal twist through the layer. First and second electrodes are proximate to first and second major surfaces of the liquid crystal layer. A first negatively birefringent compensator layer, oriented with its optical axis substantially parallel to the average direction of the optical axis within a central, nominally homeotropic region of the liquid crystal layer in its driven state, is disposed between the polarizer layer and the liquid crystal layer. A second negatively birefringent compensator layer, with a birefringence substantially the same as the birefringence of the first compensator layer and oriented with its optical axis substantially parallel to the optical axis of the first compensator layer, is disposed between the analyzer layer and the liquid crystal layer.

Abstract: A normally white super-twist nematic liquid crystal display is disclosed. Between a polarizer layer and an analyzer layer, the display includes a super-twist nematic liquid crystal cell having first and second substrates and a liquid crystal layer disposed between the first and second substrates. The display further includes at least one positively birefringent A-plate compensator layer disposed between the polarizer layer and the super-twist nematic liquid crystal cell and at least one positively birefringent A-plate compensator layer disposed between the analyzer layer and the super-twist nematic liquid crystal cell to reduce chromaticity shifts of the display at wide viewing angles and over temperature variations.

Abstract: A piezoelectric device or actuator (30) includes dimorph stack (32) attached to a support (34). Affixed to the apex of stack (32) is friction surface (36) which is held in contact with the external friction surface of a positionable object (38).

Abstract: A method to fabricate a photo-patterned organic compensator for liquid crystal displays, and the resulting compensator structure, are described. One illustrative fabrication method comprise: (1) depositing a thin film of polymerizable liquid crystal material onto one of a display's substrates; (2) orienting the liquid crystal material's director to a specified direction; (3) polymerizing the deposited thin film through an aperture mask; (4) removing the aperture mask; and (5) curing/annealing the thin film layer to yield a planar structure having substantially birefringent and isotropic regions. Complete pixelated compensators may be created by layering two or more such two-region thin films.

Abstract: A CMOS imaging system provides low noise read out and amplification for an array of passive pixels, each of which comprises a photodetector, an access MOSFET, and a second MOSFET that functions as a signal overflow shunt and a means for electrically injecting a test signal. The read out circuit for each column of pixels includes a high gain, wide bandwidth, CMOS differential amplifier, a reset switch and selectable feedback capacitors, selectable load capacitors, correlated double sampling and sample-and-hold circuits, an optional pipelining circuit, and an offset cancellation circuit connected to an output bus to suppress the input offset nonuniformity of the amplifier. For full process compatibility with standard silicided submicron CMOS and to maximize yield and minimize die cost, each photodiode may comprise the lightly doped source of its access MOSFET. Circuit complexity is restricted to the column buffers, which exploit signal processing capability inherent in CMOS.