Timex Corporation

Marshall Leibowitz

Douglas A George

Brian Faughnan

Richard Crandall

Alan E Willis

A backlighted liquid crystal display is disclosed which includes an electroluminescent backlight having a reduced amount of phosphor acting as both a source of light for viewing the display during nighttime hours and as a light diffuser for viewing the display during daytime hours. The electroluminescent backlight is made thinner while the phosphor content is optimally reduced to provide a backlight that improves the viewability of the display especially during daytime hours without the need of a transflector. Wherein the minimal amount of phosphor is dispersed in a binder in the electroluminescent layer is substantially 1 volume unit of phosphor for every 4 to 5 volume units of binder.

Electroluminescent lamp for liquid crystal display

Thin, amorphous electrochromic layers deposited on substrate electrodes by, for example, vacuum deposition techniques, are subjected to a special heat treatment at a selected high temperature for a selected short time to convert at least a free surface portion of each layer to be exposed to the electrolyte from the amorphous form to a crystalline form while preventing excessive water loss which might adversely affect the electrochromic properties of the layer for display purposes. Crystallization of at least the free surface portion of the electrochromic layer significantly increases its etch resistance whereas retention of water in the electrochromic layer maintains satisfactory electrochromic properties for display purposes.

Electrochromic films having improved etch resistance

An untreated polarizer layer which inherently exhibits liquid crystal alignment-promoting characteristics is placed on an untreated front and/or rear substrate and respective electrode layer in contact with the liquid crystal so that the polarizer layer can serve the dual function of polarizing and liquid crystal alignment means in the display, thereby simplifying display construction. If desired, the polarizer layer itself may be rubbed or otherwise mechanically treated in situ on the substrate to selectively alter its liquid crystal alignment properties. Further simplification of the display is achieved by combining the rear electrode, associated rear polarizer and liquid crystal alignment means, and reflector together in the form of a reflective metallic electrode member having a transparent, dual functioning polarizer-alignment layer on the inner surface adjacent and in contact with the liquid crystal layer of the display. A reduction in the number of layers in the display sandwich from ten to only seven is possible with the invention. A novel polarizer-alignment layer useful in simplifying the display construction is made of cyanoethylated polyvinyl alcohol or butyrate.

Simplified field effect, twisted nematic liquid crystal display

The invention provides a transparent electrode barrier layer between the metal oxide electrodes and electrochromic layers thereon in an electrochromic display in which coloration of the electrochromic layers is attributed to the incorporation of protons therein under an applied electrical potential. The electrode barrier layer minimizes the destructive reaction between the metal oxide electrodes and hydrogen from colored electrochromic layers. Display life is thereby substantially improved.

Electrode barrier layer for hydrogen-colored electrochromic displays

Thin, amorphous electrochromic layers deposited on substrate electrodes by, for example, vacuum deposition techniques, are subjected to a special heat treatment at a selected high temperature for a selected short time to convert at least a free portion of each layer to be exposed to the electrolyte from the amorphous form to a crystalline form while preventing excessive water loss which might adversely affect the electrochromic properties of the layer for display purposes. Crystallization of at least the free surface portion of the electrochromic layer significantly increases its etch resistance whereas retention of water in the electrochromic layer maintains satisfactory electrochromic properties for display purposes.

Method for making electrochromic films having improved etch resistance

A plurality of self-luminous light sources, each preferably comprising a transparent shell, a radioactive material encapsulated in the shell, and a radioluminescent material coated on the shell, are incorporated in the ion-conducting layer of an electrochromic display at selected locations behind the image-forming electrochromic segments to provide sufficient back lighting for enhanced night viewability of the display elements.

Electrochromic display having enhanced night viewability

An electrochromic display cell having in sandwich layered form a first transparent substrate with a plurality of digits each being formed thereon by a plurality of selectively energizable transparent electrodes and an electrochromic layer on each of the transparent electrodes, a second substrate with a plurality of separate and selectively energizable counter-electrodes each being associated with a digit, and a separate electrolyte layer between each counter-electrode and its associated digit. In the preferred embodiment, each corresponding transparent electrode of each digit is interconnected on the first transparent substrate to form groups of commonly energized segments with each group having a single electrical connection to/from the display.

Electrochromic display adapted for multiplexing

An electrochromic display device in layered form having a first transparent substrate with a selectively actuable transparent electrode thereon and a first electrochromic layer on said transparent electrode, in combination with a counterelectrode having a second electrochromic layer thereon, and a solid electrolyte-separator layer between said first and said second electrochromic layers, said electrolyte-separator being comprised of a cationic ion exchange resin, specifically, a membrane of the acid form of a soluble polystyrene sulfonic acid polymer chemically wetted with water.

Electrochromic device with cationic ion exchange resin separator

An electrochromic display for selectively displaying optical patterns comprising a sandwich type structure which includes transparent front electrodes, electrochromic layers on the front electrodes, an electrolyte and a special electroreactive layer on a rear electrode. The electroreactive layer, which serves as hydrogen source, is composed of electrochromic material which is first oxidized and subsequently heat treated in a hydrogen or forming gas atmosphere to improve the operating and life characteristics of the display. The electrodes are mounted or deposited respectively on parallel substrates which form the outer structures of a hermetically sealed display arrangement. The electroreactive layer can be a single layer structure serving the functions of both the rear electrode and hydrogen source material.

Electrochromic display element and process

An electrochromic display for selectively displaying optical patterns comprising a sandwich type structure which includes transparent front electrodes, electrochromic layers on the front electrodes, an electrolyte and a special electroreactive layer on a rear electrode. The electroreactive layer, which serves as hydrogen source, is composed of electrochemical material which is first oxidized and subsequently heat treated in a hydrogen or forming gas atmosphere to improve the operating and life characteristics of the display. The electrodes are mounted or deposited respectively on parallel substrates which form the outer structures of a hermetically sealed display arrangement. The electroreactive layer can be a single layer structure serving the functions of both the rear electrode and hydrogen source material.

An electrochromic display device having transparent front electrodes on a substrate, said front electrodes being coated with electrochromic material having different oxidation states for displaying optical patterns, a back electrode on a parallel substrate also coated with electrochromic material, a thin porous separator between the substrates, a liquid electrolyte contacting the electrochromic layers, said electrolyte being saturated with electrochromic materials in each of the oxidation states to reduce the degradation of the electrochromic layers as they pass through each of the oxidation states. The saturating materials are tungsten trioxide, hydrogen tungsten oxide, and tungsten dioxide in the electrochromic display described.

Electrochromic display having improved electrolyte

An electrochromic display device having transparent electrodes on a substrate and coated with electrochromic material for selectively displaying optical patterns, a counter-electrode on a parallel substrate also coated with electrochromic material, a thin porous separator membrane for closely spacing the substrates, the separator pores saturated with liquid electrolyte contacting the electrochromic layers and pigment providing a contrasting background for the first mentioned electrochromic layer and hiding the second electrochromic layer.

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Ridgefield, CT, United States of America

Marshall Leibowitz