GB1375091A - - Google Patents
Info
- Publication number
- GB1375091A GB1375091A GB13672A GB13672A GB1375091A GB 1375091 A GB1375091 A GB 1375091A GB 13672 A GB13672 A GB 13672A GB 13672 A GB13672 A GB 13672A GB 1375091 A GB1375091 A GB 1375091A
- Authority
- GB
- United Kingdom
- Prior art keywords
- beam splitter
- reflector
- light
- members
- fixed
- 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
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
- G01B9/02001—Interferometers characterised by controlling or generating intrinsic radiation properties
- G01B9/02007—Two or more frequencies or sources used for interferometric measurement
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B2290/00—Aspects of interferometers not specifically covered by any group under G01B9/02
- G01B2290/45—Multiple detectors for detecting interferometer signals
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B2290/00—Aspects of interferometers not specifically covered by any group under G01B9/02
- G01B2290/70—Using polarization in the interferometer
Abstract
1375091 Measuring the distance between two objects with an interferometer HEWLETTPACKARD CO 3 Jan 1972 [1 Feb 1971] 136/72 Heading G1A [Also in Divisions G2 and G4] In.an interferometer measuring system for measuring the distance between two members 18, 19 Fig. 2 errors due to external conditions affecting the distance between the components of the interferometer and the members 18, 19 are reduced by mounting a beam splitter on one of the members together with the reflector for light, the path length of which is fixed, and mounting the reflector for light, the path length of which is varied, on the other of the members. In the embodiment of Fig. 2 a light polarizing beam splitter 35 and fixed light reflector 37 are mounted on member 19 and a light reflector 38 is mounted on the other member 18, the arrangement being such that light from an externally mounted laser 12 is split at the beam splitter 35 into two orthogonally polarized components one being directed along the fixed path to the reflector 37 and the other being directed along the variable path to the reflector 38. The reflected light beams are recombined by the beam splitter 35 and directed to a further polarizing beam splitter 39 which separates the components into two orthogonal polarization planes for transmission to two photo-detectors 32, 33 which with associated circuitry derive a count representing the displacement between the two members 18, 19. In the embodiment of Fig. 3 the laser 41 provides a two frequency beam output f 1 and f 2 which is separated into two orthogonal components by quarter wave plate 42 and half wave plate 43. A beam splitter 44 directs a portion of the two beams to (1) a reference voltage detector 46 giving a signal f2-f1 to one input of a reversible counter 47 and (2) a polarizing beam splitter 48 which directs the component of frequency f2 to fixed reflector 49 and the component of frequency f 1 movable reflector 51. The reflected beams are recombined and directed via a demodulating polarizer 52, to a photo-detector 53 giving an output of frequency f 2 -f 1 Œ #f to the other input of the reversible counter 47 so that a count representing #f is derived. In a further embodiment Fig 4 (not shown), two distance measurements are made simultaneously. One measurement is effected by directing one component of the laser beam from a beam splitter (57) to a polarizing beam splitter (61) directing light to a fixed and movable reflector (62, 63) as in the embodiment of Fig. 3. The beam splitter (57) also directs light onto a further polarizing beam splitter (65) directing light to a fixed and movable reflector (66, 67) respectively. The reflected light is recombined at the polarizing beam splitter (65) and directed via the beam splitter (57) to a further photo-detector (68). The pitch of one movable member relative to another may be measured by directing light from a beam splitter (71) Fig. 5 (not shown), on to a reflector (52) attached to one of the members via a mirror (74) on to a reflector (73) attached to the second member so that changes in the value X1-X2 are measured. If the second reflector is mounted immediately above the beam splitter changes in the value X1-Y may be measured.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11159671A | 1971-02-01 | 1971-02-01 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1375091A true GB1375091A (en) | 1974-11-27 |
Family
ID=22339394
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB13672A Expired GB1375091A (en) | 1971-02-01 | 1972-01-03 |
Country Status (6)
Country | Link |
---|---|
CA (1) | CA950657A (en) |
DE (1) | DE2201194B2 (en) |
FR (1) | FR2124998A5 (en) |
GB (1) | GB1375091A (en) |
IT (1) | IT950612B (en) |
SE (1) | SE383780B (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ATE9183T1 (en) * | 1980-12-02 | 1984-09-15 | Dr. Johannes Heidenhain Gmbh | METHOD FOR STEP-BY-STEP MEASURING OF GEOMETRIC QUANTITIES AND DEVICES FOR IMPLEMENTING THE METHOD. |
US4509858A (en) * | 1983-01-17 | 1985-04-09 | Gca Corporation/Tropel Division | Compact, linear measurement interferometer with zero abbe error |
DE3421213C2 (en) * | 1984-06-07 | 1986-08-28 | Daimler-Benz Ag, 7000 Stuttgart | Two-channel, two-frequency laser interferometer |
DE3835892C1 (en) * | 1988-10-21 | 1990-01-11 | Daimler-Benz Aktiengesellschaft, 7000 Stuttgart, De | Long-path laser interferometer |
-
1971
- 1971-12-23 CA CA130,952,A patent/CA950657A/en not_active Expired
-
1972
- 1972-01-03 GB GB13672A patent/GB1375091A/en not_active Expired
- 1972-01-12 DE DE2201194A patent/DE2201194B2/en active Granted
- 1972-01-28 IT IT47996/72A patent/IT950612B/en active
- 1972-01-31 SE SE7201037A patent/SE383780B/en unknown
- 1972-02-01 FR FR7203288A patent/FR2124998A5/fr not_active Expired
Also Published As
Publication number | Publication date |
---|---|
DE2201194A1 (en) | 1972-08-17 |
DE2201194B2 (en) | 1973-01-04 |
IT950612B (en) | 1973-06-20 |
SE383780B (en) | 1976-03-29 |
CA950657A (en) | 1974-07-09 |
FR2124998A5 (en) | 1972-09-22 |
AU3752271A (en) | 1973-09-27 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PE20 | Patent expired after termination of 20 years |