GB1225472A - - Google Patents

Info

Publication number
GB1225472A
GB1225472A GB1225472DA GB1225472A GB 1225472 A GB1225472 A GB 1225472A GB 1225472D A GB1225472D A GB 1225472DA GB 1225472 A GB1225472 A GB 1225472A
Authority
GB
United Kingdom
Prior art keywords
photo
glasses
slide
auxiliary
march
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.)
Expired
Application number
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
Priority claimed from DE19681772031 external-priority patent/DE1772031A1/en
Priority claimed from DE19681772032 external-priority patent/DE1772032A1/en
Priority claimed from DE19681772276 external-priority patent/DE1772276C/en
Priority claimed from DE19681797070 external-priority patent/DE1797070A1/en
Application filed filed Critical
Publication of GB1225472A publication Critical patent/GB1225472A/en
Expired 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
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/14—Details
    • G03B21/53—Means for automatic focusing, e.g. to compensate thermal effects

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Switches Operated By Changes In Physical Conditions (AREA)

Abstract

1,225,472. Photo-electric positioning arrangement. E. LEITZ G.m.b.H. March 24, 1969 [March 22, 1968(2); April 24, 1968, Aug.9, 1968 (2)], No. 15303/69. Addition to 1, 177, 578. Heading G1A. In a sheet positioning arrangement as in the parent, biasing means which may comprise a mask, a reflecter, photo-cells of different effective areas, or a component unbalancing an electrical bridge, is associated with one of the light sensitive portions to start a search movement when the photo device is not illuminated; or the axis of the light rays incident on the slide and the axis of the photo-electric device include an acute angle which may be 25 degrees providing the elements do not interfere with projection; or the ratio of the components developed in the two dectector portions differs for a photographic slide without glasses, from that pertaining for components for a slide with glasses, whereby the position is modified to compensate for refraction of the inclined positioning beam within the facing glasses. This last fixture is provided by an auxiliary photoelectric device positioned to be influenced by rays reflected from the surfaces of glasses covering a transparency but not from a plain transparency. A further auxiliary photo-cell may be provided to compensate for changes in source intensity. Transistor controlled bridge circuits to which the auxiliary cells are connected are described.
GB1225472D 1968-03-22 1969-03-24 Expired GB1225472A (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
DE19681772031 DE1772031A1 (en) 1968-03-22 1968-03-22 Automatic focusing device for slide projectors
DE19681772032 DE1772032A1 (en) 1968-03-22 1968-03-22 Slide projector with an automatic focusing device
DE19681772276 DE1772276C (en) 1968-04-24 Slide projector with automatic focusing device
DE19681797070 DE1797070A1 (en) 1968-08-09 1968-08-09 Slide projector with automatic focusing device
DE19681797061 DE1797061C (en) 1968-08-09 Slide projector with automatic focusing device

Publications (1)

Publication Number Publication Date
GB1225472A true GB1225472A (en) 1971-03-17

Family

ID=27509972

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1225472D Expired GB1225472A (en) 1968-03-22 1969-03-24

Country Status (1)

Country Link
GB (1) GB1225472A (en)

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee