GB690966A - Improvements in or relating to ophthalmic testing arrangements - Google Patents

Improvements in or relating to ophthalmic testing arrangements

Info

Publication number
GB690966A
GB690966A GB373251A GB373251A GB690966A GB 690966 A GB690966 A GB 690966A GB 373251 A GB373251 A GB 373251A GB 373251 A GB373251 A GB 373251A GB 690966 A GB690966 A GB 690966A
Authority
GB
United Kingdom
Prior art keywords
screen
reflector
sight
image
projection
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
GB373251A
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.)
ELLIOT OPTICAL Co Ltd
GEOFFREY MILLS
Original Assignee
ELLIOT OPTICAL Co Ltd
GEOFFREY MILLS
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 ELLIOT OPTICAL Co Ltd, GEOFFREY MILLS filed Critical ELLIOT OPTICAL Co Ltd
Priority to GB373251A priority Critical patent/GB690966A/en
Publication of GB690966A publication Critical patent/GB690966A/en
Expired legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
    • A61B3/02—Subjective types, i.e. testing apparatus requiring the active assistance of the patient
    • A61B3/028—Subjective types, i.e. testing apparatus requiring the active assistance of the patient for testing visual acuity; for determination of refraction, e.g. phoropters
    • A61B3/032—Devices for presenting test symbols or characters, e.g. test chart projectors

Abstract

690,966. Optical projection apparatus for sight-testing. ELLIOT OPTICAL CO., Ltd., and MILLS, G. Oct. 12, 1951 [Feb. 15, 1951], No. 3732/51. Class 97 (i). In a sight-testing arrangement in which the image of a sight-chart or like, projected on a screen, is viewed by the patient by reflection in a distant mirror, a substantially vertical column is provided supporting the screen in a substantially vertical position, a reflector behind and inclined to the screen and a projection system arranged to project substantially vertically upwards on to the reflector and so to form an image of the chart on the screen. As shown, the reflector 9 and screen 1 are supported in a hood 2 on a column 3 mounted on a floor or table pedestal or on a bracket and having sliding thereon a block 6 carrying the projector. The latter includes a body 4 with spools for the projection of film strips and a gate 10, the body being rotatable about the housing of the projection lens 12 so that the angular position of the image projected on the screen may be varied. In a modification the axis of the projector is horizontal and the beam is reflected to the reflector 9 by an inclined reflector also carried by the block 6.
GB373251A 1951-02-15 1951-02-15 Improvements in or relating to ophthalmic testing arrangements Expired GB690966A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB373251A GB690966A (en) 1951-02-15 1951-02-15 Improvements in or relating to ophthalmic testing arrangements

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB373251A GB690966A (en) 1951-02-15 1951-02-15 Improvements in or relating to ophthalmic testing arrangements

Publications (1)

Publication Number Publication Date
GB690966A true GB690966A (en) 1953-04-29

Family

ID=9763906

Family Applications (1)

Application Number Title Priority Date Filing Date
GB373251A Expired GB690966A (en) 1951-02-15 1951-02-15 Improvements in or relating to ophthalmic testing arrangements

Country Status (1)

Country Link
GB (1) GB690966A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2939940A1 (en) * 1978-10-05 1980-04-10 Essilor Int METHOD AND DEVICE FOR PRESENTING TESTS AGAINST A PERSON IN DIFFERENT DISTANCES

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2939940A1 (en) * 1978-10-05 1980-04-10 Essilor Int METHOD AND DEVICE FOR PRESENTING TESTS AGAINST A PERSON IN DIFFERENT DISTANCES

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