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Display system for displaying information in the viewfinder of a camera

Assignee: Minolta Co Ltd
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Filing: 1991-05-01
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Granted: 1992-12-08
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Expires: 2011-05-01
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Abstract

Abstract A display system for displaying information in the viewfinder of a camera, capable of displaying a positive pattern indicating a distance measuring area and a light measuring area on a transparent background so that a photographing field can be seen through the transparent background of the pattern. The display system comprises a liquid crystal display of a guest-host type disposed near the focal plane of the optical system of the viewfinder. The liquid crystal display comprises transparent electrodes provided with a pattern indicating distance measuring areas and light measuring areas, a liquid crystal of a cholesteric-nematic phase transition type having a negative anistropic dielectric property as host, and a dichroic coloring matter having an anisotropic light absorption property as guest. The pattern having a high opacity is displayed on a transparent background in the viewfinder in a satisfactory contrast to the background.

Inventors

  • 👤 Hiromu Mukai
  • 👤 Kohtaro Hayashi
  • 👤 Yasuo Maeda

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 15:07
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/18; G03B17/20

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 56 words
A display system for displaying information in a viewfinder of a camera, comprising: a first liquid crystal display for displaying information inside of the viewfinder image plane; a second liquid crystal display for displaying information outside of the viewfinder image plane; and means for driving the first and second liquid crystal displays at different duty cycles.
Claim 2
Dependent Claim 56 words
A display system for displaying information in a viewfinder of a camera, comprising: a first liquid crystal display for displaying information inside of the viewfinder image plane; a second liquid crystal display for displaying information outside of the viewfinder image plane; and means for driving the first and second liquid crystal displays at different duty cycles.
Claim 3
Dependent Claim 50 words
A display system according to claim 1, wherein the driving means drives the first liquid crystal display by applying a voltage continuously across electrodes of the first liquid crystal display and drives the second liquid crystal display by applying a voltage repetitively across electrodes of the second liquid crystal display.
Claim 4
Dependent Claim 35 words
A display system according to claim 1, wherein the first liquid crystal display displays a focus detecting area and the second liquid crystal display displays photographing information such as a shutter speed and an aperture.
Claim 5
Dependent Claim 28 words
A display system according to claim 1, wherein the first liquid crystal display is a guest-host type and the second liquid crystal display is a twist nematic type.

References Cited (Backward Citations)

US3486432A Cited
US4299462A Cited
US4313657A Cited
US4627700A Cited
US4441798A Cited
US4465355A Cited
US4572617A Cited
US4827303A Cited
US4856869A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-12-08 1996-06-08 1996-12-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-12-08 2000-06-08 2000-12-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-12-08 2004-06-08 2004-12-08 $7700.00 Window Closed / Lapsed

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