JPS57124331A - Liquid crystal focusing screen for camera - Google Patents

Liquid crystal focusing screen for camera

Info

Publication number
JPS57124331A
JPS57124331A JP1061981A JP1061981A JPS57124331A JP S57124331 A JPS57124331 A JP S57124331A JP 1061981 A JP1061981 A JP 1061981A JP 1061981 A JP1061981 A JP 1061981A JP S57124331 A JPS57124331 A JP S57124331A
Authority
JP
Japan
Prior art keywords
liquid crystal
focusing
camera
focusing screen
screen
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP1061981A
Other languages
Japanese (ja)
Inventor
Mitsuharu Watanabe
Michio Tsukaki
Kazuo Shiozawa
Yoshihiro Higuchi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Konica Minolta Inc
Original Assignee
Konica Minolta Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Konica Minolta Inc filed Critical Konica Minolta Inc
Priority to JP1061981A priority Critical patent/JPS57124331A/en
Publication of JPS57124331A publication Critical patent/JPS57124331A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B13/00—Viewfinders; Focusing aids for cameras; Means for focusing for cameras; Autofocus systems for cameras
    • G03B13/18—Focusing aids
    • G03B13/24—Focusing screens

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Viewfinders (AREA)
  • Liquid Crystal (AREA)

Abstract

PURPOSE:To achieve detection of focus automatically, by making a liquid crystal screen opaque through power application, through the detection of focusing, in the focusing screen using liquid crystal. CONSTITUTION:In a camera having a liquid crystal plate 1 as a focusing screen, a comparator circuit 52 is connected to an ammeter terminal A in a bridge circuit, a low-level output is obtained to a voltage input being a certain range (taking O voltage as a center) corresponding to a focusing state by means of reference voltages 53, 54 and comparators 55, 56, the level is converted into a high level by an inverter 57, a liquid crystal plate is driven via an AC square wave generating circuit 51 to be opaque. At nonfocusing, no power is applied and the crystal plate is transparent, and the user can see a bright finder.
JP1061981A 1981-01-26 1981-01-26 Liquid crystal focusing screen for camera Pending JPS57124331A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1061981A JPS57124331A (en) 1981-01-26 1981-01-26 Liquid crystal focusing screen for camera

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1061981A JPS57124331A (en) 1981-01-26 1981-01-26 Liquid crystal focusing screen for camera

Publications (1)

Publication Number Publication Date
JPS57124331A true JPS57124331A (en) 1982-08-03

Family

ID=11755233

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1061981A Pending JPS57124331A (en) 1981-01-26 1981-01-26 Liquid crystal focusing screen for camera

Country Status (1)

Country Link
JP (1) JPS57124331A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5333031A (en) * 1991-08-21 1994-07-26 Minolta Camera Kabushiki Kaisha Camera having a liquid crystal focusing screen
JPH075101U (en) * 1993-06-25 1995-01-24 恵和商工株式会社 Composite sheet material
US5903788A (en) * 1993-01-07 1999-05-11 Minolta Co., Ltd. Camera

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5333031A (en) * 1991-08-21 1994-07-26 Minolta Camera Kabushiki Kaisha Camera having a liquid crystal focusing screen
US5903788A (en) * 1993-01-07 1999-05-11 Minolta Co., Ltd. Camera
JPH075101U (en) * 1993-06-25 1995-01-24 恵和商工株式会社 Composite sheet material

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