Liquid crystal cells – elements and systems – Particular structure – Having significant detail of cell structure only
Patent
1999-02-11
2000-10-31
Sikes, William L.
Liquid crystal cells, elements and systems
Particular structure
Having significant detail of cell structure only
349 98, G02F 11335
Patent
active
061410683
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a technical field of display devices, and more particularly, to a technical field of display devices such as reflective liquid crystal display devices which comprise a polarized light separator such as a polarizer and a reflective polarizer, and which reflects external light to effect two-color display, and an electronic apparatus such as a portable phone and a watch using the same.
BACKGROUND ART
In a conventional liquid crystal display device utilizing a variable transmission polarization axis optical element for rotating a polarization axis of transmitted light, such as a TN (Twisted Nematic) liquid crystal and an STN (Super-Twisted Nematic) liquid crystal, a structure is employed in which this variable transmission polarization axis optical element is sandwiched by two sheets of polarizers.
According to such an arrangement, only a polarized light component in a specific direction is transmitted through a first polarizer located on the side of a display screen of liquid crystal, and other polarized light components are absorbed by this first polarizer. The polarization direction of light transmitted through the first polarizer is selectively changed in response to an alignment state of liquid crystal that changes with voltage applied to the liquid crystal, and the light is incident on a second polarizer located on the other side of the liquid crystal.
In the case of a liquid crystal display device of a dot matrix system, for example, in a normally white mode, regarding each pixel, (i) in a state where a voltage is not applied to the liquid crystal, the light emitted from the liquid crystal is transmitted through the second polarizer, is further reflected by a reflecting plate located at the back thereof and thereafter, is transmitted through the second polarizer, the liquid crystal, and the first polarizer again to be emitted as display light from the display screen of the liquid crystal display device; and (ii) in a state where a voltage is applied to the liquid crystal, the light emitted from the liquid crystal is absorbed by the second polarizer, and display light is not emitted from the display screen, finally.
Alternatively, in the case of a liquid crystal display device of a segment system, for example, in a region containing segment electrodes, the display light is selectively emitted from the display screen as display light in response to a state of voltage application to the liquid crystal, as in the case of the above dot matrix system. On the other hand, in a region containing no segment electrode, the liquid crystal is always in a state of non-application of a voltage, and the external light is reflected by the reflecting plate through the polarizer and the liquid crystal to be emitted as display light from the display screen.
In this way, by controlling the quantity of display light emitted from the display screen for each of the pixels or each of the segments using the liquid crystal, polarizers and so forth arranged on the optical path while reflecting the external light incident from the display screen by a reflecting film provided inside the device, reflective display is effected.
In addition, some small liquid crystal display devices of the dot matrix system, segment system or the like for use in an electronic apparatus such as a portable phone or a wristwatch arrange two sheets of color polarizers perpendicular to each other at positions opposite to the liquid crystal to effect two-color display. The color polarizers have characteristics of transmitting a specific wavelength component (color component) and of absorbing other wavelength components (color components) when transmitting a polarized light component in a predetermined direction. According to the liquid crystal display device, a region of pixel electrodes or segment electrodes in the state of voltage application is displayed in a first color, such as red, blue, green and black, and a region of pixel electrodes or segment electrodes that is not in the state of voltage applic
REFERENCES:
patent: 5555114 (1996-09-01), Narita et al.
patent: 5619355 (1997-04-01), Sharp et al.
patent: 5627666 (1997-05-01), Sharp et al.
patent: 5712694 (1998-01-01), Taira et al.
patent: 5796454 (1998-08-01), Ma
patent: 5825444 (1998-10-01), Broer et al.
Chowdhury Tarifur R.
Seiko Epson Corporation
Sikes William L.
LandOfFree
Display devices, electronic apparatus using the same, and polari does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Display devices, electronic apparatus using the same, and polari, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Display devices, electronic apparatus using the same, and polari will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2058520