General Electric Company

Raychem Limited

John E Bigelow

Herbert S Cole

Donald E Castleberry

Siegfried Aftergut

Charles R Stein

Donald C Peroutky

Philip J Jones

Alfred O Saupe

A system and method for projecting a color image is disclosed. The system includes a light dispersing system arranged in the path of a composite light beam for separating the composite light beam into spatially separated component beams, an image display arranged in the path of the component beams for producing modulated component beams, and a beam merging system producing a second light beam by merging the modulated component beams. The method includes producing spatially separated component light beams, directing the spatially separated component light beams to the surface of an image display, modulating display cells of the image display, and producing modulated component light beams.

Color image projection system

A multi-color liquid crystal display has a one-dimensional or two-dimensional array of at least one display cell, with a plurality of different liquid crystal host/guest dichroic dye compositions in each cell. Each of the different liquid crystal compositions may be provided within separate microcapsules, with the totality of micro-capsules being blended to provide the total composition filling the cell volume or dielectric spacers may be utilized to divide the volume of each display cell into a like plurality of subvolumes, each containing a different liquid crystal material. Liquid crystal hosts of substantially-constant or variable dielectric anisotropy magnitude and polarity are selected to cause different ones of the plurality of compositions within a cell to switch between transmission and absorption of various visible-wavelengths regions as the frequency and amplitude of an electric field within the cell is varied by control electronics of a display system.

Multi-color liquid crystal display and system

Methods for matrix addressing a liquid crystal display, utilizing the cholesteric-to-nematic phase change for information display, provides a voltage to each of a plurality of scanned electrodes. A preferred voltage waveform has a first non-zero value during an erase interval and a greater non-zero value during a display-write interval. The combined erase and write intervals occur, for each scanned electrode, once during a multiplex time interval. Each of another plurality of electrodes, arranged adjacent to the remaining surface of a liquid crystal layer and perpendicular to the scanned electrodes, are sequentially energized with a non-zero voltage having a polarity change coincident with the erase and write intervals when that portion of a display at the intersection of the first and second plurality of electrodes is to be addressed. If the inverted-polarity voltage is in phase with the scan electrode voltage, the liquid crystal material is switched to the cholesteric state and absorbs incident light, whereas if the inverted-polarity voltage is out-of-phase with the scan electrode erase-write pulse, the intersection is switched to the nematic state and incident light is transmitted through the cell substantially without attenuation.

Matrix addressing of cholesteric liquid crystal display

A control for use upon a solid panel, devoid of control shaft apertures, allows data entry by rotational positioning of a human member, such as one's finger, about a pattern of a plurality of interdigitated electrodes formed upon an interior surface of the panel. The position of the member varies the capacitance between adjacent ones of the electrodes, with position-decoding electronics energizing successive ones of the plurality of electrodes with successive phases of a master signal and recovering information relating the phase of the signal returned from the control to the position of the member. A light-emitting display may be positioned behind the panel to indicate the index of the control knob by a variable-length circular bar of light, a digitized display and the like.

Capacitive touch control and display

A control for use upon a solid panel, devoid of control shaft apertures, allows data entry by rotational positioning of a sector-shaped electrode to vary the capacitance to at least one of a plurality of sector-shaped electrodes formed about a central disc upon an interior surface of the panel. A magnetizable disk is attached to the exterior of the panel, with the control knob having a magnetized member attracted to the disk for maintaining the control knob in proper position while allowing control knob rotational adjustments. Position-decoding electronics energize successive ones of the plurality of electrodes with successive phases of a master signal and recover zero-crossing information relating the phase of the signal returned from the control to the control position. A light-emitting display is positioned behind the panel to indicate the index of the control knob by a variable-length circular bar of light, a digitized display and the like.

The molecules in a twisted nematic liquid crystal are, in general, skewed relative to the optical axis of the cell (the perpendicular to the plane surfaces defining the boundaries of the crystal cell), and their birefringent effect on plane polarized light varies asymmetrically for such light making varying angles with the optical axis of the cell. When the cell is positioned between crossed polarizers and the cell is energized so that light is supposed to be completely extinguished, some rays are nevertheless transmitted so that the transmitted intensities at different viewing angles vary. To avoid this resulting variation of intensity with viewing angle, the cell is illuminated from behind with collimated light (i.e., all rays parallel to the optical axis of the cell) so that all rays 'see' the average molecular director in the same way; a solid catadroptric element is utilized to both collimate the light and achieve essentially constant luminous flux intensity upon the display. To restore a reasonably wide angle of view, a diffuser is positioned in front of the display. The invention may be used with any type of display device which has a transmission characteristic which varies with the angle of rays passing therethrough.

Evenly illuminated display devices

A control for use upon a solid panel, devoid of control shaft apertures, allows data entry by rotational positioning of an electrode to vary the capacitance to at least one of a multiplicity of electrodes formed upon an interior surface of the panel. A magnetizable disk is attached to the exterior of the panel, with the control knob having a magnetized member attracted to the disk for maintaining the control knob in proper position while allowing control knob rotational adjustments. A light-emitting display is positioned behind the panel to indicate the index of the control knob by means of a variable-length, circular bar of light.

Capacitive touch control

A printer head for use in an impact printer of the dotmatrix type utilizes a stack of pivoted thin blades, each having a printing tip at one end thereof. A pancake coil is attached to each blade for initiating selective independent movement thereof within a common, externally-produced magnetic field to efficiently convert electrical print signals to kinetic energy in each printing tip of a vertical array thereof thereby facilitating printing of symbols, characters and other indicia on underlying media with high resolution. The single magnetic-field-producing means interacts with all pancake coils of the stack of printer blades to facilitate close spacing of the printing tips for superior character printing. Resilient members are integrally formed in each blade to support the moving structure with negligible loss, thereby increasing the printing speed of the stacked blade head.

Stacked blade matrix printer heads

Gas discharge displays of the planar electrode type and having a plurality of anode or cathode electrodes connected together on a common matrix address line utilize resistive elements, having a current-voltage characteristic varying in highly exponential manner, in series between the commmon matrix line and each of the paralleled cathode or anode electrodes to facilitate current sharing therebetween during normal operation while allowing 'run-in' of the displays at relatively greater than normal currents.

DC Pop with varistor connected between control circuit and cathode

A transflective liquid crystal display capable of presenting viewable indicia to an observer stationed to the front thereof, responsive to either reflection of incident ambient light entering into display from the front thereof or transmission of light from a source behind the display, utilizes a reflective display of the type having a twisted nematic liquid crystal host-guest dichroic dye cell backed by a quarter-wave plate and a partially-reflective, partially-transmissive transflector member, in conjunction with a linear polarizer and a second quarter-wave plate arranged between the back-lighting source and the partially-transmissive member.

Transflective liquid crystal display

A variable intensity fluorescent display, utilizing fluorescent segments for forming indicia when irradiated by an ultraviolet lamp, utilizes a separate source of infrared light, such as a variable intensity incandescent lamp and deep red, or infrared, filter and the like to provide quenching action in the fluorescent material in a controlled manner.

Variable intensity fluorescent display

An improved matrix address system is disclosed wherein zero cross-talk and maximum contrast are obtained by utilizing a constant absolute magnitude data signal, and address and data signals in a voltage ratio equal to the square root of n, where n is the number of addressable columns and therefore the number of devices in a given row, so as to yield the maximum ratio, R, of the r.m.s. values of the 'on' voltage and the 'off' voltage applied to any given device, namely, R = 1 + 1/.sqroot.n.

Growing community of inventors

Clifton Park, NY, United States of America

John E Bigelow