GB909916A - Improvements relating to measuring apparatus - Google Patents
Improvements relating to measuring apparatusInfo
- Publication number
- GB909916A GB909916A GB1859758A GB1859758A GB909916A GB 909916 A GB909916 A GB 909916A GB 1859758 A GB1859758 A GB 1859758A GB 1859758 A GB1859758 A GB 1859758A GB 909916 A GB909916 A GB 909916A
- Authority
- GB
- United Kingdom
- Prior art keywords
- grating
- motor
- gratings
- pattern
- relative
- 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 abstract 5
- 238000006073 displacement reaction Methods 0.000 abstract 4
- 230000001360 synchronised effect Effects 0.000 abstract 2
- 125000004122 cyclic group Chemical group 0.000 abstract 1
- 230000001419 dependent effect Effects 0.000 abstract 1
- 230000001678 irradiating effect Effects 0.000 abstract 1
- 238000005259 measurement Methods 0.000 abstract 1
- 230000005855 radiation Effects 0.000 abstract 1
Classifications
-
- 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
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B19/00—Programme-control systems
- G05B19/02—Programme-control systems electric
- G05B19/18—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form
- G05B19/19—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by positioning or contouring control systems, e.g. to control position from one programmed point to another or to control movement along a programmed continuous path
- G05B19/33—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by positioning or contouring control systems, e.g. to control position from one programmed point to another or to control movement along a programmed continuous path using an analogue measuring device
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Human Computer Interaction (AREA)
- Manufacturing & Machinery (AREA)
- Automation & Control Theory (AREA)
- Optical Transform (AREA)
Abstract
909,916. Electric copying machines. FERRANTI Ltd. June 10, 1959 [June 11, 1958], No. 18597/58. Class 38 (6). [Also in Group XL (b)] Measuring apparatus responsive to the movement of an object relative to a reference structure comprises a first optical grating secured to the object, a second optical grating in optical registration with the first grating, the gratings being so ruled as to set up in combination with one another a control cyclic optical pattern which is displaceable in phase relative to the reference structure in dependence on object movement, a light source irradiating the pattern, a control photo-electric device irradiated by light from the pattern, a reference source providing a reference signal at a predetermined frequency, scanning means controlled by the reference signal to cause the output signal from the photo-electric device to alternate at the predetermined frequency with a phase displacement relative to the reference signal equal to the phase displacement of the pattern relative to the reference structure, a discriminator deriving a signal in continuous dependence on the phase of the signal from the photo-electric device relative to the reference signal, and utilization means responsive to the discriminator output. In the embodiment illustrated in Figs. 1 and 2, a disc 16 bearing a radial grating 15 is rotated by motor 19 across a grating 11 secured to work-table 13 moved linearly by motor 33, and across a fixed grating 12; the ensuing outputs of photo-cells 21, 22 are at a frequency determined by the speed of motor 19 and of a relative phase proportional to work-table displacement. Coarse gratings, e.g. 100 lines to the inch, are used. A magnetic tape 25 carries "command" and "reference" tracks 26, 27 respectively, the outputs from which are fed to phase discriminators 31, 35 to produce control of motor 33 dependent on the difference of the error signals from the discriminators, thus affording correct magnitude and sign of the motor control voltage. Errors in the measurement of the work-table displacement otherwise arising from imperfect disc drive or like fluctuations from lamp 17 are inherently obviated by the inclusion of photo-cell 22. An error signal from discriminator 35 is utilized to control the speed of motor 19; or the motor may be energized to run above synchronous speed and discriminator 35 output applied as an eddycurrent brake. The grating system may have unequal widths of transparent and opaque bands; one grating of each pair may be formed on a reflective base, Fig. 3 (not shown); all gratings are radial when the work-table is to be rotated; the grating on disc 16 may be spiral to permit direct motor drive, Fig. 4 (not shown), or helical on a rotated cylinder, Fig. 5 (not shown). The disc or its cylindrical counterpart may be fixed and the light source moved, e.g. by using a cathode-ray tube (C.R.T.) spot scanned along a time base synchronized with the recorded reference signal. The reference pattern need not be used, Fig. 11 (not shown). In a further embodiment, Figs. 6 and 7, the " control " light pattern is set up by gratings 51, 52 secured to the work-table and fixed frame 14 respectively, and the " reference " light pattern by similar, fixed, gratings 54, 53. The skew angles of the gratings are adjusted for equality of the wavelengths of the patterns with that of endless film 57 which carries an optical track whose density varies sinusoidally in the direction of film motion. The speed of film-driving motor 59 is controlled as in the first embodiment. Pattern-forming variants are described, Figs. 8, 9 and 10 (none shown). Infra-red radiation may be utilized; and the coarse gratings may be replaced by diffraction gratings.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1859758A GB909916A (en) | 1958-06-11 | 1958-06-11 | Improvements relating to measuring apparatus |
CH7432659A CH377544A (en) | 1958-06-11 | 1959-06-11 | Position measuring device with follow-up control, in particular for position control of machine tools |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1859758A GB909916A (en) | 1958-06-11 | 1958-06-11 | Improvements relating to measuring apparatus |
Publications (1)
Publication Number | Publication Date |
---|---|
GB909916A true GB909916A (en) | 1962-11-07 |
Family
ID=10115184
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1859758A Expired GB909916A (en) | 1958-06-11 | 1958-06-11 | Improvements relating to measuring apparatus |
Country Status (2)
Country | Link |
---|---|
CH (1) | CH377544A (en) |
GB (1) | GB909916A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1266518B (en) * | 1964-11-14 | 1968-04-18 | Zeiss Carl Fa | Length or angle measuring device |
EP0628791A2 (en) * | 1993-06-10 | 1994-12-14 | Canon Kabushiki Kaisha | Rotation detecting apparatus and scale for the same |
GB2352811A (en) * | 1999-08-06 | 2001-02-07 | Mitutoyo Corp | Optical encoder |
CN102288210A (en) * | 2010-06-07 | 2011-12-21 | 株式会社安川电机 | Encoder, servo unit and encoder manufacturing method |
EP2302333A3 (en) * | 2009-09-18 | 2012-10-24 | Kabushiki Kaisha Yaskawa Denki | Rotary encoder, rotary motor, rotary motor system, disk, and method of manufacturing rotary encoder |
-
1958
- 1958-06-11 GB GB1859758A patent/GB909916A/en not_active Expired
-
1959
- 1959-06-11 CH CH7432659A patent/CH377544A/en unknown
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1266518B (en) * | 1964-11-14 | 1968-04-18 | Zeiss Carl Fa | Length or angle measuring device |
EP0628791A2 (en) * | 1993-06-10 | 1994-12-14 | Canon Kabushiki Kaisha | Rotation detecting apparatus and scale for the same |
EP0628791A3 (en) * | 1993-06-10 | 1995-07-05 | Canon Kk | Rotation detecting apparatus and scale for the same. |
US5537210A (en) * | 1993-06-10 | 1996-07-16 | Canon Kabushiki Kaisha | Rotation detecting apparatus and scale having a multi helix diffraction grating for the same |
GB2352811A (en) * | 1999-08-06 | 2001-02-07 | Mitutoyo Corp | Optical encoder |
US6635863B1 (en) * | 1999-08-06 | 2003-10-21 | Mitutoyo Corporation | Optical encoder |
GB2352811B (en) * | 1999-08-06 | 2004-09-29 | Mitutoyo Corp | Optical encoder |
EP2302333A3 (en) * | 2009-09-18 | 2012-10-24 | Kabushiki Kaisha Yaskawa Denki | Rotary encoder, rotary motor, rotary motor system, disk, and method of manufacturing rotary encoder |
US8546744B2 (en) | 2009-09-18 | 2013-10-01 | Kabushiki Kaisha Yaskawa Denki | Rotary encoder, rotary motor, rotary motor system, disk, and method of manufacturing rotary encoder |
CN102288210A (en) * | 2010-06-07 | 2011-12-21 | 株式会社安川电机 | Encoder, servo unit and encoder manufacturing method |
CN102288210B (en) * | 2010-06-07 | 2014-12-03 | 株式会社安川电机 | Encoder, servo unit and encoder manufacturing method |
Also Published As
Publication number | Publication date |
---|---|
CH377544A (en) | 1964-05-15 |
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