GB1145721A - Optical instruments - Google Patents

Optical instruments

Info

Publication number
GB1145721A
GB1145721A GB1019366A GB1019366A GB1145721A GB 1145721 A GB1145721 A GB 1145721A GB 1019366 A GB1019366 A GB 1019366A GB 1019366 A GB1019366 A GB 1019366A GB 1145721 A GB1145721 A GB 1145721A
Authority
GB
United Kingdom
Prior art keywords
pattern
cornea
reflected
curvature
image
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
GB1019366A
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.)
OPTICAL METHODS Inc
Original Assignee
OPTICAL METHODS 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 OPTICAL METHODS Inc filed Critical OPTICAL METHODS Inc
Publication of GB1145721A publication Critical patent/GB1145721A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/60—Systems using moiré fringes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
    • G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
    • G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
    • G01D5/36—Forming the light into pulses
    • G01D5/38—Forming the light into pulses by diffraction gratings
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for

Abstract

1,145,721. Optical apparatus. OPTICAL METHODS Inc. March 8, 1966 [March 15, 1966], No.10193/66. Heading G2J. In determining the curvature of the cornea a contact lens or other reflecting surface 25, Fig. 7, a regular light pattern R, such as a series of black concentric circular lines on a transparent background, is reflected from the surface 25 and coimaged with a second pattern, such as a pattern R' identical to R so as to form a third pattern, which may be a moirÚ fringe pattern, the size of one of the patterns being varied until the third pattern is a predetermined null, the amount of such size variation providing a measure of the radius of curvature of the surface 25. As shown the pattern R is reflected by semi-reflector 86 and focused by objective 88 to form a small image on the surface of the cornea, the light being reflected back to form an image at the pattern R' which is observed by eyepiece 94. A null position is seen with the objective 88 focused on the surface of the cornea. If the instrument is moved to the left by rack and pinion 96 a secund null position is observed when the image of R is focused at the centre of curvature of the cornea. The distance moved, as read on scale 100, gives the radius of curvature of the cornea. Deviations from sphericity of the surface show as distortions in the fringe pattern. In a modification, patterns R and R' are replaced by a pattern R". In a further form Fig. 6 (not shown) an arrangement similar to a Michelson interferometer is used except that the pattern (R) is in one arm of the interferometer and the reflecting object (23) is in another arm. In another arrangement, Fig. 9 (not shown) the pattern (R) is reflected from a semireflector (108) and imaged on the cornea (25) by an objective (110), the reflected image being photographed (at F). The resultant photograph (F), Fig. 12 (not shown) is imaged by a zoom lens (142) on a master pattern (146) and the moirÚ fringes observed.
GB1019366A 1965-03-15 1966-03-08 Optical instruments Expired GB1145721A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US43974965A 1965-03-15 1965-03-15

Publications (1)

Publication Number Publication Date
GB1145721A true GB1145721A (en) 1969-03-19

Family

ID=23745986

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1019366A Expired GB1145721A (en) 1965-03-15 1966-03-08 Optical instruments

Country Status (3)

Country Link
DE (1) DE1548287A1 (en)
GB (1) GB1145721A (en)
IL (1) IL25345A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0010998A1 (en) * 1978-09-19 1980-05-14 Thomson-Csf Process for optically aligning patterns in two planes close to one another and alignment device to realize such a process
GB2126745A (en) * 1982-09-02 1984-03-28 Mo Nauchno Issledovatelskyinst Method and device for determining cornea surface topography
GB2129956A (en) * 1982-11-06 1984-05-23 Mo Nii Glaznykh Boleznei Im Ge Selecting contact lenses for visual correction using photokeratogram
US4569576A (en) * 1982-08-31 1986-02-11 Moskovsky Nauchno-Issledovatelsky Institut Glaznykh Boleznei Imeni Gelmgoltsa Method and device for determining cornea surface topography

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0010998A1 (en) * 1978-09-19 1980-05-14 Thomson-Csf Process for optically aligning patterns in two planes close to one another and alignment device to realize such a process
US4569576A (en) * 1982-08-31 1986-02-11 Moskovsky Nauchno-Issledovatelsky Institut Glaznykh Boleznei Imeni Gelmgoltsa Method and device for determining cornea surface topography
GB2126745A (en) * 1982-09-02 1984-03-28 Mo Nauchno Issledovatelskyinst Method and device for determining cornea surface topography
GB2129956A (en) * 1982-11-06 1984-05-23 Mo Nii Glaznykh Boleznei Im Ge Selecting contact lenses for visual correction using photokeratogram

Also Published As

Publication number Publication date
DE1548287A1 (en) 1970-10-08
IL25345A (en) 1969-12-31

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