GB1145721A - Optical instruments - Google Patents
Optical instrumentsInfo
- 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
Links
- 230000003287 optical effect Effects 0.000 title abstract 3
- 210000004087 cornea Anatomy 0.000 abstract 6
- 238000000034 method Methods 0.000 abstract 1
- 238000012986 modification Methods 0.000 abstract 1
- 230000004048 modification Effects 0.000 abstract 1
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
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Optics & Photonics (AREA)
- Eye Examination Apparatus (AREA)
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.
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)
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 |
-
1966
- 1966-03-08 GB GB1019366A patent/GB1145721A/en not_active Expired
- 1966-03-09 IL IL2534566A patent/IL25345A/en unknown
- 1966-03-15 DE DE19661548287 patent/DE1548287A1/en active Pending
Cited By (4)
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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