GB1216581A - Improvements in overhead projectors - Google Patents

Improvements in overhead projectors

Info

Publication number
GB1216581A
GB1216581A GB12068A GB12068A GB1216581A GB 1216581 A GB1216581 A GB 1216581A GB 12068 A GB12068 A GB 12068A GB 12068 A GB12068 A GB 12068A GB 1216581 A GB1216581 A GB 1216581A
Authority
GB
United Kingdom
Prior art keywords
lens
support
held
light source
spring clips
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
GB12068A
Inventor
William Derek Bradford
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.)
Omal Group Ltd
Original Assignee
Omal Group Ltd
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 Omal Group Ltd filed Critical Omal Group Ltd
Priority to GB12068A priority Critical patent/GB1216581A/en
Publication of GB1216581A publication Critical patent/GB1216581A/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
    • G03B21/132—Overhead projectors, i.e. capable of projecting hand-writing or drawing during action

Abstract

1,216,581. Overhead projector; lens and mirror mounts. OMAL GROUP Ltd. Dec.31, 1968 [Jan.1, 1968], No.120/68. Headings G2A and G2J. An overhead projection comprises a light source 15, Fresnel lenses 17, 18, transparency support 14 and a projection head 12 in which the image of light source 15 is formed, having at least one fixed lens 21, at least one interchangeable lens 20 and a mirror 23 pivotable about an axis perpendicular to the optical axis. The lens 20 is held in an annular support 25 by spring clips 27 and the removeable support 25 is held in the projection head 12 by spring clips 31. The inter-changeable lens 20 may be mounted in a turret or slide for selective positioning in line with fixed lens 21.
GB12068A 1968-01-01 1968-01-01 Improvements in overhead projectors Expired GB1216581A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB12068A GB1216581A (en) 1968-01-01 1968-01-01 Improvements in overhead projectors

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB12068A GB1216581A (en) 1968-01-01 1968-01-01 Improvements in overhead projectors

Publications (1)

Publication Number Publication Date
GB1216581A true GB1216581A (en) 1970-12-23

Family

ID=9698772

Family Applications (1)

Application Number Title Priority Date Filing Date
GB12068A Expired GB1216581A (en) 1968-01-01 1968-01-01 Improvements in overhead projectors

Country Status (1)

Country Link
GB (1) GB1216581A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4002408A (en) * 1971-10-14 1977-01-11 Gakken Co. Ltd. System and device for overhead projection
US4080052A (en) * 1977-01-13 1978-03-21 Gte Sylvania Incorporated Overhead projection system with lens assembly having concentrically-oriented condensing lenses
WO1982000529A1 (en) * 1980-07-30 1982-02-18 Asteroe U An optical system for projection
EP0063425A1 (en) * 1981-04-16 1982-10-27 Minnesota Mining And Manufacturing Company Variable focal length projection lens for use on overhead projectors

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4002408A (en) * 1971-10-14 1977-01-11 Gakken Co. Ltd. System and device for overhead projection
US4080052A (en) * 1977-01-13 1978-03-21 Gte Sylvania Incorporated Overhead projection system with lens assembly having concentrically-oriented condensing lenses
WO1982000529A1 (en) * 1980-07-30 1982-02-18 Asteroe U An optical system for projection
EP0063425A1 (en) * 1981-04-16 1982-10-27 Minnesota Mining And Manufacturing Company Variable focal length projection lens for use on overhead projectors

Similar Documents

Publication Publication Date Title
GB1372462A (en) Overhead slide projector
GB1125887A (en) Photo-printing apparatus
GB1148363A (en) Improvements in or relating to optical projectors
GB1260920A (en) Improvements in and relating to photographic exposure arrangements
GB943346A (en) Optical projector
GB1216581A (en) Improvements in overhead projectors
GB1282033A (en) A catadioptric telephoto objective lens system
GB711367A (en) Improvements in or relating to stereoscopic viewing apparatus
GB1046783A (en) Optical apparatus
GB1449413A (en) Microfiche camera editing device
GB1203748A (en) Improvement in or relating to an apparatus for projecting written characters
GB1275620A (en) Optical system
GB1216140A (en) Rotating optical rectifying device for cinematographic apparatus
GB1280977A (en) Optical projection device
GB1029138A (en) Optic lens systems
FR2455756A1 (en) Epidiascope for transparencies and overlays - has dioptric lens which projects image onto fresnel lens on table for reflecting onto screen
GB1537304A (en) Microform reader
GB1184719A (en) Improvements in or relating to Projection Systems
GB1324115A (en) Optical systems
GB1223409A (en) Improvements in and relating to photo-copying arrangements
GB1254343A (en) Interchangeable lens camera
GB1211135A (en) Improvements relating to optical projectors
SU135756A1 (en) High-speed movie camera shooting
GB1429992A (en) Optical projecting apparatus
GB1283772A (en) Improvements relating to apparatus for use in image projection