Communications: electrical – Land vehicle alarms or indicators – Internal alarm or indicator responsive to a condition of the...
Patent
1989-07-12
1990-08-14
Miller, Stanley D.
Communications: electrical
Land vehicle alarms or indicators
Internal alarm or indicator responsive to a condition of the...
350336, 350339R, 340765, 340784, G02F 1133, G09G 318, G09G 336
Patent
active
049482327
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a device for the presentation of information, especially alpha-numeric characters, comprising a display means which is constructed from a plurality of character-forming liquid crystal elements and is arranged to be activated by an electronic means.
BACKGROUND OF THE INVENTION
Display devices which are based on the use of so-called liquid crystals, during the recent years have found their application in many different fields. As examples there may be mentioned digital watches, different types of measuring instruments, and electronic applications in the provision of informative messages in the form of e.g. combinations of figures and letters. Such display devices of the liquid crystal display (LCD) type contain a number of liquid crystal cells or elements which are usually segment-oriented so as to form the actual characters, e.g. 7-segment or 16-segment alpha-numeric characters. As known, the liquid crystals are molecules which are capable of electric polarization, and a liquid crystal element is activated by the application of a suitable DC voltage, e.g. 5 volts, so that the liquid is polarized and changes from being transparent to a dark grey tone. When placing a polarization filter over a liquid crystal element at right angles to the polarization direction, a much darker tone appears when the element is activated, so that better contrast is achieved.
In the previously known liquid crystal displays one has, in accordance with the conventional technique, considered it to be necessary to use a non-transparent contrast foil at the rear side of the LCD unit in order to improve the contrast between the displayed characters and the surroundings. The contrast foil causes the LCD unit to be non-transparent also in the non-activated condition, and this represents a limitation in the possible applications. Thus, the contrast foil delimits the use to the display of "two-dimensional" information, i.e. information which is present in a plane such as is the case in the above-mentioned fields of application.
A device of the introductorily stated type is known from DE publication print No. 3 120 601. This known device is intended for use in "observation devices", vehicles and the like, and comprises a liquid crystal display plate which, in use, can be placed in a viewer's field of view or is arranged in the marginal region thereof in such a manner that it does not interrupt the visual observation in the viewer's field of view. The display plate consists of a pair of parallel glass plates with a liquid crystal mixture and electrodes placed therebetween, and behind the display plate there is placed a means for illuminating the plate in dim light and in darkness. Further, the plate is also preferably covered by a partly reflecting foil to increase the contrast. Thus, the device is a quite visible unit also in non-activated condition, even if it is designed with a view not to disturb the visual observation in a viewer's field of view.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a device extending the use of liquid crystal elements for the display of information in such a manner that the display device, when being placed on a transparent surface, such as a display window or the like, is invisible in non-activated condition, and wherein desired information can be displayed instantaneously by means of a possibly programmable control means.
The above object is achieved with a device of the introductorily stated type which, according to the invention, is characterized in that the liquid crystal elements are disposed on a transparent support plate and are mounted on the plate in such a design that the plate with characters mounted thereon is approximately 100% transparent in non-activated condition of the elements, and that the elements are connected to a contact means which, at an edge portion of the support plate, is fitted for connection to the electronic means, this being arranged, in a manner known per se, for selectively controllable activation of the liqu
REFERENCES:
patent: 4013344 (1977-03-01), Bescond
patent: 4295712 (1981-10-01), Ishiwatari
patent: 4342031 (1982-07-01), Lapeyre
patent: 4455185 (1984-06-01), Sasaki et al.
patent: 4474432 (1984-10-01), Takamatsu et al.
patent: 4501471 (1985-02-01), Culley et al.
patent: 4616903 (1986-10-01), Fergason
Aviram, A., "Packaging of Liquid Crystal Displays," IBM Technical Disclosure Bulletin, vol. 15, No. 2, (Jul. 1972) pp. 580-581.
Gross Anita Pellman
Miller Stanley D.
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