DE2714324A1 - Photoelectric system for travelled distance measurement - has reflecting scale grid, transparent reference grid and two photoelectric receivers - Google Patents
Photoelectric system for travelled distance measurement - has reflecting scale grid, transparent reference grid and two photoelectric receiversInfo
- Publication number
- DE2714324A1 DE2714324A1 DE19772714324 DE2714324A DE2714324A1 DE 2714324 A1 DE2714324 A1 DE 2714324A1 DE 19772714324 DE19772714324 DE 19772714324 DE 2714324 A DE2714324 A DE 2714324A DE 2714324 A1 DE2714324 A1 DE 2714324A1
- Authority
- DE
- Germany
- Prior art keywords
- grid
- grating
- light
- photoelectric
- distance
- 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.)
- Granted
Links
- 238000005259 measurement Methods 0.000 title 1
- 230000003287 optical effect Effects 0.000 claims description 3
- 230000003993 interaction Effects 0.000 description 2
- 230000010363 phase shift Effects 0.000 description 2
- 241000306729 Ligur Species 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 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
Abstract
Description
Fotoelektrisches Auflicht-Wegmeßsystem Photoelectric incident light measuring system
Die Erfindung betriff ein fotoelektrisches Auflicht-Wegmeßsystem nach Patent ... (Patentanmeldung P 26 53 545.5) mit einer Lichtquelle, einem reflektierenden Maßstabgitter, einem transparenten Referenzgitter mit vom Maßstabgitter unterschiedlicher Gitterkonstante, einem Luftabstand zwischen beiden Gittern und mindestens einem fotoelektrischen Empfänger, bei dem die optisch wirksamen Gitterkonstanten beider Gitter im Verhältnis dR = dM (1 # v) zueinander stehen, wobei dR und dM die optisch wirksamen Gitterkonstanten des Referenzgitters M und des Maßstabgitters, v = einen Verzerrungsy + dM faktor und y den Abstand der hellen und dunklen durch die beiden Gitter erzeugten Vernierstreifen bedeuten, bei dem mindestens zwei fotoelektrische Empfänger in Lichtrichtung gemassen zumindest angenähert in einem Abstand x von dem Gitter mit der jeweils größeren optisch wirksamen Gitterkonstante entfernt sind, für den x = a/v gilt mit einem optisch wirksamen Luftabstand a zwischen Referenz- und Maßstabgitter und bei dem der Abstand der fotoelektrischen Empfänger voneinander senkrecht zur Vernierstreifenrichtung ungleich n . y/2 mit n = 1, 2, 3, ... ist.The invention relates to a photoelectric incident-light measuring system Patent ... (patent application P 26 53 545.5) with a light source, a reflective one Scale grid, a transparent reference grid with a different from the scale grid Grid constant, an air gap between the two grids and at least one Photoelectric receiver in which the optically effective grating constants of both Grids are in the ratio dR = dM (1 # v) to each other, where dR and dM are the optical effective grid constants of the reference grid M and the scale grid, v = one Distortion y + dM factor and y the distance of the light and dark by the two Grating generated vernier strips mean in which at least two photoelectric Receiver measured in the direction of light at least approximately at a distance x from removed from the grating with the larger optically effective grating constant, for x = a / v, with an optically effective air gap a between reference and scale grids and in which the distance of the photoelectric receivers from one another perpendicular to the direction of the vernier strip not equal to n. y / 2 with n = 1, 2, 3, ...
Die in der Hauptanmeldung P 26 53 545.5 dargestellten Ausführungsbeispiele zeigen als Referenz- und Maßstabgitter jeweils Amplitudengitter. Dabei ist unmittelbar erkennbar, daß bei einem Steg-/Lückeverhältnis von 1:1 die lichtundurchlässigen Stege des Referenzgitters von vornherein 50 % des Beleuchtungslichts unterdrücken.The embodiments shown in the main application P 26 53 545.5 show amplitude grids as reference and scale grids. It is immediate it can be seen that with a bridge / gap ratio of 1: 1 the opaque Suppress 50% of the illuminating light from the start.
Soweit die Stege diesen Lichtanteil nicht vollständig absorbieren, entstehen empfängerseitig zusätzlich störende Reflexe. Prozentual dieselben Lichtverluste entstehen bei;;; Austritt des am Malistabgitter reflektierten Lichts aus dem Meßsystem.If the webs do not completely absorb this portion of light, additional disturbing reflections arise on the receiver side. The same percentage of light losses arise at ;;; Exit of the light reflected at the Malist grating from the measuring system.
Der vorliegenden Erfindung liegt daher die Aufgabe zugrunde, eine weitere Ausgestaltung des iii der llauptanmeldung beschriebenen Systems anzugeben, die lichtstärker und weitgehend frei von störenden Reflexen ist.The present invention is therefore based on the object of a specify further configuration of the system described in the main application, which is more luminous and largely free of annoying reflections.
Diese Aufgabe wird erfindungsgemäß dadurch gelöst, daß das Referenzgitter ein Phasengitter ist, dessen Beugungscharakteristik unter Berücksichtigung des Verzerrungsfaktors v zumindest angenähert mit <1er des Maßstabgitters übereinstimmt.According to the invention, this object is achieved in that the reference grid is a phase grating whose diffraction characteristic takes into account the distortion factor v at least approximately corresponds to <1s of the scale grid.
Der Phasenhub zwischen den einzelnen Strukturelementen des Referenzgitters kann einem optischen Gangunterschied von etwa einer viertel Wellenlänge des wirksamen Beleuchtungslichts entsprechen, wenn die körperlich ausgebildete Gitterkonstante des Heferellzgitters Gleich der optisch wirksamen Gitterkonstanten ç nach der Hauptanmeldung ist Ein Ausführungsbeispiel der erfindungsgemäßen Anordnung ist in der Zeichnung schematisch dargestellt und wird nachfolgend bes.chrieben. Im einzelnen zeigen: Fig. la die Intensitätsverteilung in den Jlauptbougungsordnungen bei einein Amplitudengitter, Fig. 1b die Intensitätsverteilung in den Hauptbeugungs ordnungen bei einem Phasengitter mit #/4 Phasenhub, Fig. 2 ein Auflicllt-Weeme Usys tenl, bei dem das lieferenzgitter ein Phasengitter mit #/4 Phasenhub ist.The phase shift between the individual structural elements of the reference grid can have an optical path difference of about a quarter wavelength of the effective Illuminating light correspond if the physically formed grating constant des Heferellzgitter Equal to the optically effective lattice constant ç according to the main application An embodiment of the arrangement according to the invention is shown in the drawing shown schematically and is described below. Show in detail: Fig. La shows the intensity distribution in the main roughness orders with an amplitude grating, Fig. 1b shows the intensity distribution in the main diffraction orders in a phase grating with # / 4 phase deviation, Fig. 2 shows a Auflicllt-Weeme Usys tenl in which the reference grating is a phase grating with # / 4 phase deviation.
Die liguren la und ib zeigen iii; Vergleich die Lichtintensitäten in den Hauptbeugungsordnungen bei einem Durchlicht-Amplitudengitter und einem Durchlicht-Phasengitter. Abgesehen von den unvermeidbaren 12eflexionsverlusten an Luft/Glas-Flächen tritt beim Phasengitter nahezu das gesamte ankommende Licht durch das Gitter hindurch. Jedes Phasengitter mit von A/2 (k= Wellenlänge des wirksamen Beleuchtungslichts) abweichendem Phasenhub zwischen den einzelnen Strukturelementen weist auch Lichtanteile in der 0. Beugungsordnung auf. Wenn der Phasenhub etwa k/4 entspricht, dann zeigt sich, daß die Lichtintensitäten in der +1. und der -1. Beugungsordnung zusammen der Lichtintensität in der 0. Beugungsordnung entsprecllen. Das Phasengitter verhält sich daher über einen bestimmten Phasenhubbereich hinsichtlich seiner Beugungscharakteristik genauso wie ein Amplitudengitter gleicher Gitterkonstante mit dem Vorteil einer nahezu verdoppelten Lichtstärke.The ligures la and ib show iii; Compare the light intensities in the main diffraction orders in a transmitted-light amplitude grating and a transmitted-light phase grating. Apart from the unavoidable reflection losses on air / glass surfaces with the phase grating almost all of the incoming light passes through the grating. Each phase grating with from A / 2 (k = wavelength of the effective illuminating light) deviating phase deviation between the individual structural elements also has light components in the 0th order of diffraction. If the phase deviation is about k / 4, then shows that the light intensities in the +1. and the -1. Diffraction order together correspond to the light intensity in the 0th order of diffraction. The phase grating behaves therefore over a certain phase deviation range with regard to its diffraction characteristics just like an amplitude grating of the same grating constant with the advantage of a almost doubled light intensity.
Bei der Erklärung des Funktionsprinzips der Ausführungsbeispiele nacli der llauptanmeldung wurde von einem geometrisch-optisch erzeugten Schattenbild ausgegangen, das im Zusammenwirken des Iteferenz- und des Mabstabgitters entsteht. Selbstverständlich ließe sich das entstehende Streifenmuster weniger anschaulich auch wellenoptisch durch Interferenzen zwischen gebeugten Strahlenbündeln erklären. Eine solche Erklärung würde unmittelbar auch bei einem Aufbau mit einem Phasengitter als Referenzgitter anwendbar sein, da dieses ja keine anschaulich erklärbaren "Schaltten" wirft. lJa oben jedoch festgestellt wurde, dat3 sich tlas Phasengitter unter bestimmten Voraussetzungen beugungsmäßig wie ein Amplitudengitter verhält und experimentell bestätigt wird, daß das Phasengitter dieselbe Funktion ausübt wie das npli tuden-Hferenzgit ter, wird auch hier dieselbe Darstellungsweise verwendet wie in der Hauptanmeldung.When explaining the functional principle of the exemplary embodiments nacli The main registration was based on a geometrically-optically generated silhouette, which arises in the interaction of the Iteference and the scale grid. Of course the resulting stripe pattern could also be less clearly illustrated in terms of wave optics explain by interference between diffracted beams. Such a statement would also be used directly in a setup with a phase grating as the reference grating be applicable, since this does not throw any clearly explainable "switches". lYes above However, it has been established that the phase grating can be used under certain conditions behaves diffractively like an amplitude grating and is confirmed experimentally, that the phase grating performs the same function as the nplituden reference grating, The same representation is used here as in the main application.
In Fig. 2 ist das Referenzgitter 11 ein Phasongitter mit vorzugsweise \/4 Phasenhub zwischen den einzelnen Strukturelementen. Das Mef3system wird beispielsweise durch eine ausgedehnte Lichtquelle 10 ausgeleuchtet.In Fig. 2, the reference grid 11 is a phase grid with preferably \ / 4 phase shift between the individual structural elements. The Mef3system is for example illuminated by an extended light source 10.
Die an den Stegen des Maßstabgitters 12 reflektierten Lichtanteile erzeugen nach Wechselwirkung mit deiii Maßstabgitter 11 in der Ebene 13 das Vernier-Streifenmuster. Dabei wird in analoger Betrachtungsweise angenommen, daß die Furchen des Phasengitters dei: durch lässigen Bereichen eines Amplitudengitters und die Stege den undurchlässigeii Bereichen eines Amplitudengitters entsprechen. Diese geometrisch-optische Modellvorstellung ist im Ergebnis in Übereinstimmung mit dem Experiment.The light components reflected on the bars of the scale grating 12 after interaction with the scale grid 11 in the plane 13 produce the vernier stripe pattern. It is assumed in an analogous way that the grooves of the phase grating dei: through permeable areas of an amplitude grating and the webs the impermeableeii Correspond to areas of an amplitude grating. This geometrical-optical model concept is in accordance with the experiment as a result.
In der Ebene 13 entsteht danach ein aus Iie Llen uiid dunklen Streifen bestehendes Vernier-Streifenmuster mit einem Abstand y/2 zwischen den helleii und dunklen Streifen. Vorzugsweise im Abstand y/4 sind in der Ebene 13 fotoelektrische Empfänger 14, 15, 16, 17 angeordnot, die bei einer Relativverschiebung zwischen Referenz- und Maßstabgitter mit periodisch wechselnden, zueinander phasenverschobenen Lichtflüssen beaufschlagt werden. Die Auswertung der entstehenden elektrischen Signale erfolgt in bekannter Weise.In level 13, a strip of dark and dark lines is then created existing vernier stripe pattern with a distance y / 2 between the helleii and dark stripes. Preferably at a distance y / 4 there are 13 photoelectric ones in the plane Receivers 14, 15, 16, 17 are arranged, which in the event of a relative displacement between Reference and scale grids with periodically changing, mutually phase-shifted Light fluxes are applied. The evaluation of the resulting electrical signals takes place in a known manner.
L e e r s e i t eL e r s e i t e
Claims (2)
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19772714324 DE2714324C2 (en) | 1977-03-31 | 1977-03-31 | Photoelectric reflected-light distance measuring device |
CH1407077A CH626169A5 (en) | 1976-11-25 | 1977-11-17 | |
US05/854,380 US4176276A (en) | 1976-11-25 | 1977-11-23 | Photoelectric incident light distance measuring device |
GB48944/77A GB1592705A (en) | 1976-11-25 | 1977-11-24 | Optical travel measuring device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19772714324 DE2714324C2 (en) | 1977-03-31 | 1977-03-31 | Photoelectric reflected-light distance measuring device |
Publications (2)
Publication Number | Publication Date |
---|---|
DE2714324A1 true DE2714324A1 (en) | 1978-10-05 |
DE2714324C2 DE2714324C2 (en) | 1985-01-24 |
Family
ID=6005221
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE19772714324 Expired DE2714324C2 (en) | 1976-11-25 | 1977-03-31 | Photoelectric reflected-light distance measuring device |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE2714324C2 (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0163362A1 (en) * | 1984-05-31 | 1985-12-04 | Dr. Johannes Heidenhain GmbH | Displacement measuring apparatus and method |
DE19918101A1 (en) * | 1999-04-22 | 2000-10-26 | Heidenhain Gmbh Dr Johannes | Optical position measurement device, has scanning unit with detector arrangement with blocks of detector elements in measurement direction with period derived from Vernier period |
US6472658B2 (en) | 1997-12-10 | 2002-10-29 | Dr. Johannes Heidenhain Gmbh | Photoelectric position measuring system that optimizes modulation of a scanning device and the intensity of a reference mark signal |
EP1293758A1 (en) * | 2001-09-12 | 2003-03-19 | OPTOLAB Licensing GmbH | Measuring body for position measuring systems |
US6552810B1 (en) | 1999-02-04 | 2003-04-22 | Dr. Johannes Hiedenhein Gmbh | Optical measuring system |
WO2004010170A1 (en) * | 2002-07-19 | 2004-01-29 | Optolab Licensing Gmbh | Optical determination of a position or length |
DE112004002777B4 (en) * | 2004-03-03 | 2013-11-07 | Mitsubishi Denki K.K. | Optical encoder |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3541199C1 (en) * | 1985-11-21 | 1987-06-25 | Heidenhain Gmbh Dr Johannes | Photoelectric position measuring device |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2362731A1 (en) * | 1973-12-17 | 1975-06-19 | Leitz Ernst Gmbh | Position signal generator for length and angle measurement - operates with multiple data obtained from single track |
-
1977
- 1977-03-31 DE DE19772714324 patent/DE2714324C2/en not_active Expired
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2362731A1 (en) * | 1973-12-17 | 1975-06-19 | Leitz Ernst Gmbh | Position signal generator for length and angle measurement - operates with multiple data obtained from single track |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0163362A1 (en) * | 1984-05-31 | 1985-12-04 | Dr. Johannes Heidenhain GmbH | Displacement measuring apparatus and method |
US6472658B2 (en) | 1997-12-10 | 2002-10-29 | Dr. Johannes Heidenhain Gmbh | Photoelectric position measuring system that optimizes modulation of a scanning device and the intensity of a reference mark signal |
US6552810B1 (en) | 1999-02-04 | 2003-04-22 | Dr. Johannes Hiedenhein Gmbh | Optical measuring system |
DE19918101A1 (en) * | 1999-04-22 | 2000-10-26 | Heidenhain Gmbh Dr Johannes | Optical position measurement device, has scanning unit with detector arrangement with blocks of detector elements in measurement direction with period derived from Vernier period |
US6794637B1 (en) | 1999-04-22 | 2004-09-21 | Dr. Johannas Heidenhain Gmbh | Optical device for measuring position |
EP1293758A1 (en) * | 2001-09-12 | 2003-03-19 | OPTOLAB Licensing GmbH | Measuring body for position measuring systems |
WO2004010170A1 (en) * | 2002-07-19 | 2004-01-29 | Optolab Licensing Gmbh | Optical determination of a position or length |
DE112004002777B4 (en) * | 2004-03-03 | 2013-11-07 | Mitsubishi Denki K.K. | Optical encoder |
Also Published As
Publication number | Publication date |
---|---|
DE2714324C2 (en) | 1985-01-24 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CH626169A5 (en) | ||
EP0425726B1 (en) | Position measuring device | |
DE3705653C1 (en) | Photoelectric position-measuring device | |
EP0451474B1 (en) | Procedure and device to measure without contact the surface contours of an object | |
DE1962099C3 (en) | Optical index grating and process for its manufacture | |
DE3541199C1 (en) | Photoelectric position measuring device | |
DE2003492A1 (en) | Measuring method for step encoders for measuring lengths or angles as well as arrangements for carrying out this measuring method | |
DE3727188A1 (en) | OPTICAL SHIFT DETECTING DEVICE | |
EP0387520B1 (en) | Position-measuring installation | |
DE19754595B4 (en) | Photoelectric position measuring device | |
DE102005006247A1 (en) | Position measuring device | |
EP0481356A2 (en) | Optical system utilizing polarization | |
DE2413423A1 (en) | METHOD AND DEVICE FOR REDUCING OPTICAL NOISE | |
DE10058239B4 (en) | A position | |
DE2714324A1 (en) | Photoelectric system for travelled distance measurement - has reflecting scale grid, transparent reference grid and two photoelectric receivers | |
EP0083689A1 (en) | Photoelectric incremental length or angle measuring device | |
EP3339811A1 (en) | Optical positioning device | |
DE2653545C2 (en) | Photoelectric reflected-light distance measuring device | |
EP0747674B1 (en) | Photo-electric position measuring device | |
EP1028309B1 (en) | Optical encoder | |
DE4006365A1 (en) | Position measuring device used as distance sensor - uses retroreflection to provide interfering light beams providing phase shift proportional to relative spacing | |
DE3730091A1 (en) | INTERFEROMETRIC DISTANCE MEASURING DEVICE | |
EP0218151B1 (en) | Measuring process and device for the contactless determination of the diameters of thin wires | |
EP0434855B1 (en) | Position-measuring device | |
EP0279944A2 (en) | Photoelectrical position measurement device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
8110 | Request for examination paragraph 44 | ||
AF | Is addition to no. |
Ref country code: DE Ref document number: 2653545 Format of ref document f/p: P |
|
D2 | Grant after examination | ||
8363 | Opposition against the patent | ||
8365 | Fully valid after opposition proceedings | ||
8327 | Change in the person/name/address of the patent owner |
Owner name: LEICA INDUSTRIEVERWALTUNG GMBH, 6330 WETZLAR, DE |