CN1144063C - Optical translation measurement - Google Patents
Optical translation measurement Download PDFInfo
- Publication number
- CN1144063C CN1144063C CNB998002534A CN99800253A CN1144063C CN 1144063 C CN1144063 C CN 1144063C CN B998002534 A CNB998002534 A CN B998002534A CN 99800253 A CN99800253 A CN 99800253A CN 1144063 C CN1144063 C CN 1144063C
- Authority
- CN
- China
- Prior art keywords
- light
- detector
- grating
- motion
- reflection
- 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 - Lifetime
Links
- 238000005259 measurement Methods 0.000 title claims abstract description 115
- 230000003287 optical effect Effects 0.000 title claims description 170
- 238000013519 translation Methods 0.000 title claims description 137
- 230000033001 locomotion Effects 0.000 claims abstract description 290
- 238000005286 illumination Methods 0.000 claims abstract description 150
- 238000000034 method Methods 0.000 claims abstract description 149
- 230000010355 oscillation Effects 0.000 claims description 116
- 238000001514 detection method Methods 0.000 claims description 87
- 230000010287 polarization Effects 0.000 claims description 74
- 230000001427 coherent effect Effects 0.000 claims description 44
- 230000007246 mechanism Effects 0.000 claims description 35
- 230000036961 partial effect Effects 0.000 claims description 29
- 230000008569 process Effects 0.000 claims description 12
- 230000004044 response Effects 0.000 claims description 11
- 239000003550 marker Substances 0.000 claims description 4
- 230000008878 coupling Effects 0.000 claims description 2
- 238000010168 coupling process Methods 0.000 claims description 2
- 238000005859 coupling reaction Methods 0.000 claims description 2
- 230000008447 perception Effects 0.000 claims 1
- 230000000694 effects Effects 0.000 abstract description 18
- 239000000203 mixture Substances 0.000 description 59
- 230000008859 change Effects 0.000 description 41
- 230000005540 biological transmission Effects 0.000 description 31
- 241000699666 Mus <mouse, genus> Species 0.000 description 30
- 230000010363 phase shift Effects 0.000 description 28
- 238000001914 filtration Methods 0.000 description 27
- 238000006073 displacement reaction Methods 0.000 description 20
- 230000006870 function Effects 0.000 description 20
- 239000000463 material Substances 0.000 description 14
- 230000003068 static effect Effects 0.000 description 14
- 230000008901 benefit Effects 0.000 description 12
- 230000010354 integration Effects 0.000 description 12
- 238000010586 diagram Methods 0.000 description 11
- 238000009826 distribution Methods 0.000 description 11
- 210000003128 head Anatomy 0.000 description 11
- 238000012014 optical coherence tomography Methods 0.000 description 10
- 239000000758 substrate Substances 0.000 description 10
- 230000014509 gene expression Effects 0.000 description 9
- 239000011248 coating agent Substances 0.000 description 8
- 238000000576 coating method Methods 0.000 description 8
- 239000002245 particle Substances 0.000 description 8
- 238000004441 surface measurement Methods 0.000 description 8
- 230000003321 amplification Effects 0.000 description 7
- 238000004458 analytical method Methods 0.000 description 7
- 238000003199 nucleic acid amplification method Methods 0.000 description 7
- 230000000737 periodic effect Effects 0.000 description 7
- 230000005855 radiation Effects 0.000 description 7
- 238000000691 measurement method Methods 0.000 description 6
- 238000012545 processing Methods 0.000 description 6
- 230000011514 reflex Effects 0.000 description 6
- 230000003595 spectral effect Effects 0.000 description 6
- 230000002776 aggregation Effects 0.000 description 5
- 238000004220 aggregation Methods 0.000 description 5
- 238000013461 design Methods 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 5
- 239000000835 fiber Substances 0.000 description 5
- 238000002310 reflectometry Methods 0.000 description 5
- 239000000523 sample Substances 0.000 description 5
- 238000013459 approach Methods 0.000 description 4
- 239000008280 blood Substances 0.000 description 4
- 210000004369 blood Anatomy 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000012937 correction Methods 0.000 description 4
- 238000009792 diffusion process Methods 0.000 description 4
- 238000005315 distribution function Methods 0.000 description 4
- 230000005684 electric field Effects 0.000 description 4
- 230000001965 increasing effect Effects 0.000 description 4
- 239000013307 optical fiber Substances 0.000 description 4
- 238000007639 printing Methods 0.000 description 4
- 230000035945 sensitivity Effects 0.000 description 4
- 238000002834 transmittance Methods 0.000 description 4
- 230000003044 adaptive effect Effects 0.000 description 3
- 239000000654 additive Substances 0.000 description 3
- 230000000996 additive effect Effects 0.000 description 3
- 201000009310 astigmatism Diseases 0.000 description 3
- 238000005388 cross polarization Methods 0.000 description 3
- 238000000354 decomposition reaction Methods 0.000 description 3
- 230000008030 elimination Effects 0.000 description 3
- 238000003379 elimination reaction Methods 0.000 description 3
- 238000005530 etching Methods 0.000 description 3
- 239000000284 extract Substances 0.000 description 3
- 238000003384 imaging method Methods 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 238000013508 migration Methods 0.000 description 3
- 238000010606 normalization Methods 0.000 description 3
- 230000003071 parasitic effect Effects 0.000 description 3
- 230000001681 protective effect Effects 0.000 description 3
- 230000002829 reductive effect Effects 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 239000006117 anti-reflective coating Substances 0.000 description 2
- 238000000149 argon plasma sintering Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 239000004568 cement Substances 0.000 description 2
- 230000000295 complement effect Effects 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 230000005284 excitation Effects 0.000 description 2
- 230000008676 import Effects 0.000 description 2
- 230000001788 irregular Effects 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000006798 recombination Effects 0.000 description 2
- 238000005215 recombination Methods 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 238000010897 surface acoustic wave method Methods 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 239000012780 transparent material Substances 0.000 description 2
- 230000004304 visual acuity Effects 0.000 description 2
- IPWKGIFRRBGCJO-IMJSIDKUSA-N Ala-Ser Chemical compound C[C@H]([NH3+])C(=O)N[C@@H](CO)C([O-])=O IPWKGIFRRBGCJO-IMJSIDKUSA-N 0.000 description 1
- BHELIUBJHYAEDK-OAIUPTLZSA-N Aspoxicillin Chemical compound C1([C@H](C(=O)N[C@@H]2C(N3[C@H](C(C)(C)S[C@@H]32)C(O)=O)=O)NC(=O)[C@H](N)CC(=O)NC)=CC=C(O)C=C1 BHELIUBJHYAEDK-OAIUPTLZSA-N 0.000 description 1
- 238000012935 Averaging Methods 0.000 description 1
- 241000446313 Lamella Species 0.000 description 1
- 241001465754 Metazoa Species 0.000 description 1
- 241000699660 Mus musculus Species 0.000 description 1
- 108091028043 Nucleic acid sequence Proteins 0.000 description 1
- 102000011842 Serrate-Jagged Proteins Human genes 0.000 description 1
- 108010036039 Serrate-Jagged Proteins Proteins 0.000 description 1
- 102100029469 WD repeat and HMG-box DNA-binding protein 1 Human genes 0.000 description 1
- 101710097421 WD repeat and HMG-box DNA-binding protein 1 Proteins 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 230000000386 athletic effect Effects 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000004422 calculation algorithm Methods 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000001447 compensatory effect Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 230000001143 conditioned effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000006059 cover glass Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 238000004512 die casting Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000001727 in vivo Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 230000001795 light effect Effects 0.000 description 1
- 238000012886 linear function Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 210000002445 nipple Anatomy 0.000 description 1
- 230000024241 parasitism Effects 0.000 description 1
- 238000006303 photolysis reaction Methods 0.000 description 1
- 230000015843 photosynthesis, light reaction Effects 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 238000005295 random walk Methods 0.000 description 1
- 239000013074 reference sample Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000007634 remodeling Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000013517 stratification Methods 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000005308 sum rule Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 230000036962 time dependent Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- 238000000827 velocimetry Methods 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/0304—Detection arrangements using opto-electronic means
- G06F3/0317—Detection arrangements using opto-electronic means in co-operation with a patterned surface, e.g. absolute position or relative movement detection for an optical mouse or pen positioned with respect to a coded surface
-
- 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
- G01D5/347—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 using displacement encoding scales
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
- G01P3/36—Devices characterised by the use of optical means, e.g. using infrared, visible, or ultraviolet light
- G01P3/366—Devices characterised by the use of optical means, e.g. using infrared, visible, or ultraviolet light by using diffraction of light
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
- G01P3/64—Devices characterised by the determination of the time taken to traverse a fixed distance
- G01P3/80—Devices characterised by the determination of the time taken to traverse a fixed distance using auto-correlation or cross-correlation detection means
- G01P3/806—Devices characterised by the determination of the time taken to traverse a fixed distance using auto-correlation or cross-correlation detection means in devices of the type to be classified in G01P3/68
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/50—Systems of measurement based on relative movement of target
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/481—Constructional features, e.g. arrangements of optical elements
- G01S7/4811—Constructional features, e.g. arrangements of optical elements common to transmitter and receiver
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/0304—Detection arrangements using opto-electronic means
- G06F3/0312—Detection arrangements using opto-electronic means for tracking the rotation of a spherical or circular member, e.g. optical rotary encoders used in mice or trackballs using a tracking ball or in mouse scroll wheels
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/033—Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor
- G06F3/0354—Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor with detection of 2D relative movements between the device, or an operating part thereof, and a plane or surface, e.g. 2D mice, trackballs, pens or pucks
- G06F3/03543—Mice or pucks
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/033—Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor
- G06F3/0354—Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor with detection of 2D relative movements between the device, or an operating part thereof, and a plane or surface, e.g. 2D mice, trackballs, pens or pucks
- G06F3/03545—Pens or stylus
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/033—Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor
- G06F3/0354—Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor with detection of 2D relative movements between the device, or an operating part thereof, and a plane or surface, e.g. 2D mice, trackballs, pens or pucks
- G06F3/03547—Touch pads, in which fingers can move on a surface
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/033—Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor
- G06F3/0354—Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor with detection of 2D relative movements between the device, or an operating part thereof, and a plane or surface, e.g. 2D mice, trackballs, pens or pucks
- G06F3/03548—Sliders, in which the moving part moves in a plane
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/042—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by opto-electronic means
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/042—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by opto-electronic means
- G06F3/0421—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by opto-electronic means by interrupting or reflecting a light beam, e.g. optical touch-screen
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2203/00—Indexing scheme relating to G06F3/00 - G06F3/048
- G06F2203/033—Indexing scheme relating to G06F3/033
- G06F2203/0338—Fingerprint track pad, i.e. fingerprint sensor used as pointing device tracking the fingertip image
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Human Computer Interaction (AREA)
- Electromagnetism (AREA)
- Remote Sensing (AREA)
- Radar, Positioning & Navigation (AREA)
- Computer Networks & Wireless Communication (AREA)
- Power Engineering (AREA)
- Length Measuring Devices By Optical Means (AREA)
- Optical Radar Systems And Details Thereof (AREA)
- Optical Transform (AREA)
- Position Input By Displaying (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
A method for determining the relative motion of a surface with respect to a measurement device comprising: illuminating the surface with incident illumination; detecting illumination reflected from the surface to form at least one detected signal; and determining the amount of relative motion parallel to the surface from said at least one detected signal, characterized in that said determining includes correcting for the effects of relative motion perpendicular to the surface.
Description
The field of the invention
The present invention relates to speed and translation measurement field, relate to method and apparatus more particularly about the noncontact optical measurement of speed and translation.
Background of the present invention
Exist and measure an object with respect to the speed of measuring system and/or the various optical meanss of motion.The kind of measured object and the kind of motion have determined the characteristic of the whole bag of tricks and equipment.
The kind that can survey object can be divided into several groups roughly, comprising:
The object that specific pattern is arranged, for example a scale.
Reflecting object, for example a catoptron.
Small-particle (or some particles), for example some omen particles or the bubble that floats on a liquid.
The surface that the optical contrast is arranged, for example Line Chart or point diagram.
Optical diffuser object, for example blank sheet of paper.
The kind that can survey motion can be divided into several groups roughly, comprising:
Towards or the axially-movable of measurement mechanism dorsad.
Laterally (or tangential) motion, wherein between measurement mechanism and the object apart from substantially constant.
Rotatablely move, wherein object changes with respect to the direction of measurement mechanism.
It also is useful coming the category measurement device according to the number of the number (one dimension, two dimension or three-dimensional) of obtainable direction of measurement simultaneously and key element (light source, photo-detector, lens or the like).
Be noted that a certain specific method may with above-mentioned classification in more than one group be associated.
Many systems that can utilize optical instrument to carry out the non-cpntact measurement of traversing speed of object and/or motion have been reported.These methods have comprised speckle (Speckle) speed-measuring method and laser-Doppler (Doppler) speed-measuring method.Have understanding the significant additive method of the present invention: image speed measurement method, homodyne/heterodyne Doppler range rate measurement or interference technique and optical coherence tomography (OCT).
The speckle speed-measuring method is usually based on following a few thing principle:
Need the object of measured motion with an illumination of coherent light source.
Illuminated object (being generally an opaque surface) is made up of a plurality of scattered elements, and each dispersing element has the reflection coefficient of himself and with respect to the phase shift of other scattered elements.
Each reflection coefficient and phase shift are at random basically.A specified point place in the space, the electric field amplitude that produces by object reflection be each illuminated scattered elements reflection vector and, wherein the reflection vector of each element contains an additive phase composition that depends on the distance between this point and each element.
Contribution is total when being addition in phase when each, and the light intensity at a some place will be high; Contribution is total when being anti-phase ground addition (promptly subtracting each other) when each, and the light intensity at a some place will be low.
Because the relative phase delay of each light source point is relevant with the position on the plane surface, so will not form an image that the bright dark areas of stochastic distribution is arranged (not being on the point) on this plane.This image is called " speckle image ", and it is made up of some bright and dark speckles (differentiable " speckle ").
Typically " speckle " size (the typical mean distance of intensity generation significant change) depends primarily on: the distance between light wavelength, object and the speckle image plane and the size in illuminated zone.
When object when observing the plane motion of speckle image thereon, speckle image also will be moved (because some scattered elements will be left illuminated zone with same transverse velocity basically, other scattered elements will enter illuminated zone, so speckle image also will change).
Allow speckle image pass through a structure of forming by a series of replace transparent and opaque or reflection lines, speckle image is modulated.This structure generally is a pure transmission grating, and is placed on ideally near the position of detector place, to obtain maximum contrast.
Detector converts the light intensity by this structure to an electric signal, and this electric signal is the function (normally linear function) of light intensity.
When object moves with respect to measurement mechanism, speckle image will be modulated by this structure, make that the light intensity that arrives detector is periodic.This cycle is proportional to the lines interval of structure, is inversely proportional to relative velocity.
Can find oscillation frequency by the appropriate signals analysis, this frequency meter is understood the relative velocity between object and the measurement mechanism.
In these methods, high-precision frequency is determined to require that a big detector is arranged, and the signal of high-contrast requires a little detector.One piece of title of Popov (popov) and Wei Sailuofu (Veselov) has provided the mathematical analysis of speckle speed-measuring method precision for the paper (SPIE0-8194-2264-9196) of " Tangential Velocity Measurements ofDiffuse Objects by Using Modulated Dynamic Speckle (utilizing the dynamic speckle of modulation that the tangential velocity of diffusion object is measured) ".
Authorize Fu Laowa people's such as (Flower) U.S. Patent No. 3,432,237 and described a kind of speckle velocity-measuring system, wherein modulate speckle image with a transmission pattern or a pin hole.When using pin hole, the light intensity that sees through when on behalf of each single speckle, signal will cross pin hole changes.
The U.S. Patent No. 3,737,233 of authorizing Bo Lao people such as (Blau) has adopted two detectors, attempts to solve the direction uncertain problem that is present in many speckle velocities measurements.Illustrated that wherein contains two systems that respectively carry the detector of a transmission grating.Grating is static with respect to its detector, and another grating moves with respect to its detector.According to comparison, can determine the sign and the size of speed to two signals that detector produced.
Authorize the hair not people's such as (Maughmer) U.S. Patent No. 3,856,403 also attempt to avoid the direction uncertain problem by a moving grating is set.Wherein by allowing grating to be higher than the speed motion of the greatest hope relative velocity between surface and the speed measuring device, coming provides a biasing for velocity survey.This frequency displacement has reduced the influence that total light intensity (direct current and low frequency composition) changes, thereby has increased dynamic range and the precision measured.
The PCT bulletin WO 86/06845 that authorizes Gardner people such as (Ghardner) has illustrated a kind of like this system, wherein by the speckle detector signal is deducted one from the reference sample value of light source light with the DC (direct current) that reduces detectable signal and the amplitude of low frequency signal composition.Reference signal is to be proportional to total light intensity on the detector, changes influence to measuring thereby can reduce or get rid of total light intensity.
According to explanation wherein, reference signal is to produce with a beam splitter between surface measurements and main detector, this beam splitter realizes that with grating its transmitted light directive main detector carries out speckle to be surveyed, and reflected light then reflexes to and produces reference signal on the reference detector.Perhaps utilize second group of detector that reference signal is provided.In an embodiment of the disclosure, two signals have identical DC composition and opposite AC (interchange) composition, so their difference signal has not only been removed the composition of DC (or near DC) basically, and have increased the AC composition significantly.
In U.S. Patent No. 4,794, in 384, Jackson (Jackson) has described a kind of system, and wherein the speckle image from the measured surface reflection is formed on a two-dimensional CCD (charge-coupled image sensor) array.By obtain the relevant surface translation that just can find out on the two-dimensional directional between the successive images with electronic method.He has also described the application of his device as " linerless optical mouse device ".
The image speed measurement method is measured the translational speed of an image on the plane of delineation.This image must contain some elements that contrast is arranged.A line image (the spitting image of grating) carries out spatial modulation to image, and light-sensitive detector is then measured the light intensity through this pattern.Like this, between speed image and detector AC composition, set up the relation of speed/frequency.Usually, line image is with respect to detector motion, so frequency is biased.So solved the direction uncertain problem and expanded dynamic range.
One piece of paper of Lee (Li) and A Lujia (Aruga) " Velocity Sensing byIllumination with a Laser-Beam Pattern (throwing light on speed of detection) " (Applied Optics with laser beam pattern, 32, p.2320,1993) a kind of speed measurement method has been described, wherein object is not by the illumination of one-period linear (being to allow the picture of object pass through this pattern).This line image is to obtain by the laser beam of an expansion is seen through one-period transmission grating (or linear).According to the method for this suggestion, object still needs the element of contrast.
Between image speed measurement method (IV) and the speckle velocimetry (SV) many difference are arranged.Particularly, random image forces generation by coherent source in SV, supposes then that in IV image has contained suitable contrast element.What in addition, SV measured is the tangential velocity of object.And the IV measurement is angular velocity (speed of image in the plane of delineation is proportional to the angular velocity of sight line).
In the U.S. Patent No. 3,511,150 of authorizing Witter Buddhist nun people such as (whitney), the two-dimension translational of line image has produced a frequency displacement.The bead moulding pattern of single rotation some specific elongated opening places in a circular masks have produced the translation line image that is necessary.Utilize an additional detector of measuring still image can measure frequency displacement online.Line image is divided into two zones, and each zone is used for measuring different velocity ranges.This system is that picture is fuzzy to be designed to reduce for the picture motion in the compensation aeroplane photography basically.In addition, it also can be used for the missile homing head.
The U.S. Patent No. 2,772,479 of authorizing Dao Yier (Doyle) has illustrated a kind of image speed measurement system, wherein produces frequency offset by the grating of a position on rotating band.
The laser Doppler velocimeter general using is passed through the formed two bundle laser of light source beam splitting, and this two-beam is interfered in known position.Process interferes a light scattering object in space on the light scattering to of two light beams detector.A vibration composition is arranged in the detector signal, and its frequency is relevant with object speed.This phenomenon can be explained with two kinds of methods.A kind of conoscope image that forms based on two-beam of explaining.Intensity in interfering the space periodically changes between bright plane and dark plane.Scattering is proportional to the light of light intensity through the object on these planes.Therefore, the light that detects is proportional to object and is modulated perpendicular to the frequency of the speed component of these interference planes.Such fact has been considered in second kind of explanation, and promptly process has the object in space of two light beams with this two-beam of scattering.Frequency displacement all takes place because of Doppler effect in each reflected light.Yet because the angle difference of two bundle incident lights, so their Doppler shift is also inequality.Two reflected light interfere on detector, have produced beat signal, and its frequency equals the poor of two Doppler shifts.So this difference is proportional to the speed component of object perpendicular to interference plane.
Usually give in addition frequency offset of a light beam, make zero object speed will produce the measured value of non-zero-frequency.This has solved direction of motion uncertain problem (because can not distinguish positive and negative frequency) and has greatly increased dynamic range (to the sensitivity of low velocity) by the signal that generation is away from the DC composition.Frequency offset also has other advantages of aspects such as signal identification and locking.
Authorize Kato people's such as (kato) U.S. Patent No. 5,587,785 and described a this system.Linear frequency sweep realizes frequency offset by carrying out fast to it before light beam of light source is by beam splitting.The method of beam splitting makes that life period postpones between two light beams that obtain.Because frequency is scanning, so delay will cause the fixed frequency difference between two light beams.
By light source being had the further beam splitting of other delay, can extract a plurality of light beams that have the different frequency biasing.Utilize each this delay to measure a different speed dynamic range then.
Ma Cibala people's such as (Matsubara) paper " Simultaneous Measurementof the Velocity and Displacement of the Moving Rough Surface by aLaser Doppler Velocimeter (utilizing laser Doppler velocimeter to measure the speed and the displacement of motion rough surface simultaneously) " (Applied Optics, 36, p.4516,1997) provided mathematical analysis and the simulation result that utilizes LDV (laser Doppler velocimeter) to measure the rough surface transverse velocity.Wherein also proposing can be according to calculating vertically displacement by two with the surperficial simultaneously-measured result of detector that different distance arranged.
In homodyne/heterodyne Doppler measurement, a coherent source is divided into two light beams.The object of a light beam (" master " light beam) illumination its speed to be measured.Another light beam (" reference " light beam) is by a reference element reflection as a measuring system part that is generally catoptron.By the light of object and reference element reflection by recombination (realizing by same beam splitter usually) and be directed to a light-sensitive detector.
Move because of Doppler effect from the light frequency of object reflection, amount of movement is proportional to the speed component of object in the angular bisector direction of main beam and folded light beam.So,, then will detect axially-movable if folded light beam overlaps with main beam.
Detector is sensitive to light intensity, promptly be sensitive to electric field square.If the electric field that detector receives from reference path is E
0(t)=E
0Cos (w
0T+
0), the electric field that receives from object is (E
0+ E
1)
2=E
0 2+ E
0E
1+ E
1 2
First time constant that is detected device of following formula right-hand member is average, becomes a DC composition.Usually the intensity of reference beam is much larger than the light intensity that arrives detector from object, so last generally can be ignored.Launch middle entry:
E
0E
1＝E
0E
1cos(ω
0t+
0)cos(ω
1t+
1)
＝1/2?E
0E
1[cos((ω
0+ω
1)t+
0÷
1)+cos((ω
0-ω
1)t÷
0-
1)]
Can obviously find out E from this formula
0E
1Contain two vibration items are arranged.One of them vibration Xiang Yiyue doubles the hunting of frequency of optical frequency, and the time constant that is detected device is on average become zero.Second with frequency w
0-w
1(promptly being same as the frequency shift amount that causes because of Doppler effect) vibration.So detector output signal comprises a hunting of frequency composition that can characterize tested speed.
Usually add a frequency offset to reference beam.When adding this frequency offset, be called " heterodyne detection ".
Authorize Bern people's such as (Byrne) U.S. Patent No. 5,588,437 and described a kind of system, wherein by biological tissue of a LASER Light Source illumination.Be used as reference beam from the light of skin surface reflection, and the light that the blood below flowing in skin reflects is as zero-difference detection light.Like this, skin has played the effect of the diffuse type beam splitter of close measured object.Utilizing skin is that the mass motion of health can not influence measurement as an advantage of beam splitter.What measure has only relative motion between blood and the skin.This system has used two pairs of detectors.Every pair of detector can both produce a differential signal.This helps to reduce DC and the interference of low frequency composition to measuring.An optical beam scanning system has provided the figure of two-dimentional rheography.
In optical coherence tomography (OCT), the light source of a low degree of coherence (" white light ") is directed to and focuses on one and is sampled in the volume.With a beam splitter the photoconduction of a light source part to reference path.The light path of reference path is controllable.From the light of source reflection with from the light of reference path with a beam splitter (usually and be used for the same beam splitter of beam splitting light source light) recombination.Light-sensitive detector is measured the light intensity in conjunction with light.Because the coherent length of light source is very short, thus have only from be centered close to apart from the distance of light source be same as the reference light light path point the small size internal reflection light just and reference light generation coherent interference.Not relevant from the light that other volumes of sample reflect with reference light.The reference light light path is changed (usually for example with the form periodic variation of sawtooth wave) linearly.Make and on depth direction, to sample sample.In addition, in measurement, introduced Doppler shift, made and in high dynamic range, clearly to survey the coherent interference volume.
In common OCT,, provide the contrast images that is sampled volume by obtaining the change in depth of reflection size.In advanced OCT, survey frequency displacement, and the size and Orientation of the relative velocity between it and sampling volume (in coherent ranges) and the measuring system is connected with respect to nominal Doppler frequency.
Authorize Shi Wangxun people's such as (Swanson) U.S. Patent No. 5,459,570 and described a kind of basic OCT system and many application of this system.
Yi Zhate people's such as (Izatt) paper " In vivo Bidirectional Color DopplerFlow Imaging of Picoliter Blood Volumes Using Optical CoherenceTomography (utilizing optical coherence tomography skin to be risen the two-way color Doppler's liquid flow image of live body of volume blood) " (Optcis Letter 22, p.1439,1997) a kind of OCT based on optical fiber with velocity imaging ability has been described.Before using the catoptron reflection of a fiber optic splitter before the sample reflection of light from main optical path and from reference path light path is separated, and rightabout two reflected light are combined.
Su Hala people's such as (Suhara) paper " Monolithic Integrated-OpticPosition/Displacemant Sensor Using Waveguide Gratings and QW-DFB Laser (utilize the monolithic integrated optics position/displacement detector of waveguide optical grating and QW-DFB (quantum well one distributed feed-back) laser instrument ") (IEEE Photon.Technol.Lett.7, p1195,1995) described the fully integrated interferometer of a kind of monolithic, catoptron of its energy measurement is to the variation of the distance of measurement mechanism.This device utilizes a reflection diffraction element (focusing distributed Bragg reflector) conduct in the light source light path to close beam splitter and local oscillations light (localoscillator) reverberator.Orientation detection is to obtain by an energy is introduced static phase shift between each detector signal layout.
Above-mentioned listed each all is incorporated herein by reference with reference to property patent, patent disclosure and list of references.
General introduction of the present invention
The invention provides a kind of optical translation measurement (OTM) method and apparatus on the generalized form, they can provide about the amount of the relative translation between device and the adjacent object and the information of direction (can choose wantonly).Object is preferably coarse at least partially, and is close to device.Terminology used here " coarse " or " diffusion " mean that optics is irregular or inhomogeneous.Especially, object can have the opaque or translucent surface of diffusion, for example paper.This instructions is mainly discussed the translation of this diffusing surface or determining of speed.Yet should be appreciated that many methods of the present invention also can be applicable to determine the translation of other type of object, for example may be the translation of the little scattering particle that floats on a liquid.As below will illustrating, the translation of object means that its space rotation can ignore.
First aspect according to some preferred embodiments of the invention the invention provides from heterodyne or zero-difference detection by the non-speckle image signal of non-Doppler that phase place and/or oscillation amplitude change derived of the light of optics irregular surface reflection.
Second aspect that can be applicable to various motions or speed detection method according to some preferred embodiments of the invention the invention provides a kind of like this system, wherein an energy reflecting part reflection of incident light device is placed on the near surface that will measure its motion.This reverberator provides local oscillated signal, and this code book expropriation of land is concerned with in the light from surface reflection.Of the present invention this is applicable to Doppler's method and non-Doppler's method of motion detection on the one hand simultaneously.
In a preferred embodiment of the invention, the partial reflection device is a grating, and by the grating measured surface that throws light on.In a preferred embodiment of the invention, this raster overlay a part of measured surface, and have bigger transmissivity.In the preferred embodiment of the present invention, to pass through grating from surface reflection.Special in the preferred embodiment that utilizes aspect the 3rd of the present invention, reflection is useful with combining of part transmission.
The 3rd aspect according to some preferred embodiments of the invention provides a kind of asymmetrical transmission pattern to help determine the direction of motion on surface.
Phase shift has been introduced in the 4th aspect according to some preferred embodiments of the invention between at least a portion light of at least a portion reflected light of partial reflection device and surface reflection.This phase shift makes can determine direction of motion, increases dynamic range and improves signal to noise ratio (S/N ratio).
In preferred embodiments more of the present invention, this phase shift can be dynamic, promptly changes in time.This phase change can be by making reverberator along moving perpendicular to surface or the direction that is parallel to surface or both combinations and easily realizing.In addition, can be the motion of a pattern on the reverberator, for example play the motion of the standing wave of grating effect in surface acoustic wave (SAW) element.What see motion from this angle is pattern rather than entire emission device on the reverberator.Perhaps, can for example in light path, insert a piezoelectric, introduce phase shift by the light path between periodic variation reverberator and the surface.
Phase shift also can be static.Way is to introduce this static phase shift between each polarization composition of in a light beam (or in portion of energy of this light beam) easily.Respective phase changes between each detectable signal by measuring, and more specifically, by measuring the sign of phase change between each signal, can determine travel direction.
In the preferred embodiment of having used aspect this more of the present invention, utilized a polarizer to make the light generation polarization of surface reflection.When the surface was non-maintenance polarization, this point was with particular importance.
The 5th aspect according to some preferred embodiments of the invention provides based on Doppler effect, and the apparent motion on the direction that is parallel to the surface is surveyed.In this one side of the present invention, single light beam can an angle incide in the surface, perhaps at least can be perpendicular to surperficial incident.
The 6th aspect according to some preferred embodiments of the invention provides and utilized single illuminating bundle and single reverberator to produce the local oscillations reference beam to carry out two dimension or three-dimensional translation detection simultaneously.In a preferred embodiment of the invention, use the translation of determining two dimension by the signal that single detector produced.
The 7th aspect according to some preferred embodiments of the invention provides a kind of spatial filter, and making only has the single spatial frequency composition in the surface reflection to be detected the device detection basically.
In the preferred embodiment that combines aspect this more of the present invention, spatial filter comprises lens and a pin hole that is arranged on the focus place of these lens.
The reflected light on surface is preferably collimated, and spatial filter carries out filtering to reflected light, and making only has basically in the surface reflection that the light on single direction just incides on the detector.
The 8th aspect according to some preferred embodiments of the invention, spatial filter is realized by one " equivalent pinhole ".This equivalent pinhole is by obtaining for example focusing on detector from the such local oscillations field of the light of an optical grating reflection or diffraction.In this way, the feasible amplification that only on the focus point of local oscillations field, just obtains the surface reflection field.
The preferred embodiment of the present invention of having utilized equivalent pinhole is than being easier to aim at and have looser tolerance requirement.When local oscillations is that non-zero order diffraction light from a grating will be especially like this when obtaining, this is because the position of pin hole is with relevant with wavelength in this case.So when using equivalent pinhole rather than physical pin, the requirement of the wavelength stability of lighting source is wanted much loose.
A kind of device in accordance with a preferred embodiment of the present invention comprises a light source, a grating, a spatial filter, a photo-detector and some signal processing circuits.It is the light of partial coherence at least that light source provides what be directed to the surface, make the light of a part from optical grating reflection or back to diffraction, the directive detector.Grating is arranged between surface and the light source, preferably near the surface.Interfere to the light of diffraction from the light of surface reflection and from optical grating reflection or back.Contain a vibration composition in the detector signal, this composition has been represented the translation of surface with respect to optical devices.What participate in interference can be light from the grating regular reflection, also can be any first-order diffraction light of grating.Before being detected the device detection, light is preferably by spatial filtering.Two-dimension translational is measured and can be realized like this: allow the two or more detectors of optical illumination of two or more quadrature orders of reflection of a two-dimensional grating, perhaps respectively both direction is used two gratings that separate.The measurement of the third dimension can be calculated derivation by vector is made in the translation that records on the same axle not at the same level time, wherein used the unlike signal analytical technology to same signal.
Different with the detection of translational movement absolute size, optional translation direction is surveyed and is preferably realized so that frequency offset to be provided by the modulated grating position.Perhaps can import frequency offset by the light path that changes between grating and the surface.Perhaps, between different polarization compositions, introduce phase shift, thereby the phase differential relevant with direction between the two corresponding detectable signals is provided.Perhaps, direction can be determined with additive method.
The 9th aspect of some preferred embodiments of the invention relates to other methods of determining direction of motion.In having embodied the present invention's some preferred embodiments aspect this, utilize the mechanical motion of optical element to determine direction of motion.In preferred embodiments more of the present invention, be provided with two detectors.The motion of a direction will cause grating to reflect or the light of diffraction to the illumination of one of them detector.The motion of another direction causes the illumination to another detector.
The tenth aspect of preferred embodiments more of the present invention relates to a kind of method of utilizing the Doppler shift of surface reflection.The local oscillations field provides with the moving surface light that reflecting surface reflected at an angle by one.The two-beam that reflecting surface and moving surface reflected interferes on detector, produces the signal that its frequency is proportional to the relative motion between two surfaces.The advantage of this method is not need grating, and the frequency stability of alignment precision and illumination light is unimportant.
The whole bag of tricks of the present invention and device can be widely used in the application that needs are measured translation.One of application is " a linerless Genius mouse ", by for example moving this Genius mouse on light diffusion such as paper or the desktop surface, just can control the motion of cursor effectively.It is " touch-type indication device " that another typical case of the present invention uses, its finger on a device opening the paired cursor of movement conversion or any other be subjected to the control of the entity of translation or speed control.
According to a preferred embodiment of the present invention, measuring equipment comprises a light source that partially coherent light can be provided at least.The light of this light source is directed to the grating of an one dimension or two dimension, and the latter preferably is close to the surface.Interfere from grating with from surface reflection, and be pooled on the photo-detector by a spatial filter (for example lens and position are at the pin hole at its focus place).To contain beat signal in the signal that obtains relevant for the relative translation between optical device and the surface.In preferred embodiments more of the present invention, directly measure translational movement, thereby can not be subjected to the error that velocity variations causes by the zero crossings of the detector signal of vibration is counted.For these preferred embodiments of the present invention, set up instantaneous substantially position and determined.
The size and Orientation that needs translation in the time of in many application.In a preferred embodiment of the invention, this realizes by introducing a dynamic phase changer (for example piezoelectric transducer), this device produces asymmetric phase shift variations (typically being the zigzag waveform) between two reflected light on grating and surface, make and can extract directional information simply.
In another preferred embodiment of the present invention, between the different polarization composition of a light beam, introduce static phase shift, and utilize the phase differential as a result between the corresponding detectable signal to determine direction.
Perhaps, orientation detection can be realized like this, promptly adopt preferably custom-designed asymmetric transmission pattern as grating/array (for example other shapes zig-zag transmission or described herein), add the proper signal of detector output signal is handled and operation.At other speed-measuring methods for example equally also is to be used as the means that direction of motion is surveyed with asymmetric transmission pattern in the speckle speed-measuring method.Perhaps, but can also utilize an energy to come travel direction to survey according to direction of motion mechanical motion element of toggle reflections light between each detector.
The translation coherent detection of no speckle can be realized like this: collect scattered light (through the light of grating and passive movement surface reflection) with a position at the spatial filter at the focus place of lens (for example combination of condenser lens and pin hole or single-mode fiber).Combined with a local oscillations field (it is preferably by the light of grating self reflection or diffraction) from the light of surface reflection, this preferably also is a part of having passed through the light beam of spatial filter.Provide the amplification of the signal that the strength sensitive photo-detector detects with the interference of strong local oscillations radiant.This coherent detection method is called zero-difference detection.
Spatial filter can be from the light of surface reflection spatially on aggregation to a detector, makes phase place from the light of surperficial diverse location reflection not change basically during with respect to detector motion on the surface.In addition, the phase place of scattered elements (the detector place) has linear relationship with the surface translation amount on the surface.Also have, say that ideally spatial filter also is used for local oscillations light is filtered, make detector can only aggregation be no more than an interference fringe in local oscillations light and the surface reflection optical interference.
Under an extreme case, incide lip-deep (promptly being plane wave) that only collimates fully.At this moment spatial filter can be a pin hole at lens and its focus place simply.Any translation on surface can not change the relative phase of the light of spatial filter institute aggregation.This also collimates fully by reflection on reverberator or grating or the formed local oscillations light beam of diffraction, so it also can will produce the single interference striped on detector by spatial filter (placement of spatial filter makes the picture of light source drop in the pin hole).There is not what restriction (about spatial filtering) for distance between reverberator and the surface.
On another was extreme, the distance between surface and the reverberator can be ignored.This will allow to use is not the incident beam of collimation basically, even still can keep from the relative phase of the light of surface reflection when surface translation simultaneously, and keeps local oscillations light and surface reflection that same focus point is arranged.Randomly, spatial filter also can and be positioned at as the pin hole on the catoptrical picture plane of the light source of a local oscillations light with lens and realize.
Have only a speckle at most for what make detector institute aggregation, the size of pin hole necessarily can not surpass by the size of the formed speckle of surface reflection (therefore this measurement is called " no speckle ").So if detector itself is sufficiently little, it just can play the effect of spatial filter part, thereby no longer needs pin hole.
The constant relative phase at detector place and can satisfy with multiple optically basic method of equal value with the optimum condition of the single interference striped of local oscillations light.Especially, can meet the demands with the single convergent lens that is placed on from before or after the reflection of light of local oscillations reflective optical system.Perhaps, lens and reverberator can be combined into single optical device.Perhaps, can between beam splitter and surface, place a collimation lens (promptly have only directive and just pass through these lens) from the light on surface.
Nonideal spatial filtering (for example when pin hole too big, or when it does not have the position in reflected light or local oscillations light or both focal spot on surface) signal will be degraded, and may increase the noise of measurement.The program that degrades depends on what and the type that departs from ideal conditions.
In a method for optimizing according to the present invention, surface illumination and reference light all use same optical element (preferably grating) to provide.Surface light and reference light be shared single light path through the great majority in the device or whole optical element the time.In addition, can add the modulation of spatial amplitude and/or phase place to lip-deep light, thereby provide extra means for the motion of surface measurements with the grating correlation.Especially, even for the also tangential translation of energy measurement of the grating direct reflection that does not have Doppler shift, and can accomplish identification to direction of motion.
The 11 aspect according to some preferred embodiments of the invention, an integrated motion detection system provides the signal that can indicate the size of motion and randomly indicate travel direction.In a preferred embodiment of the invention, some element at least of this motion detection system is mounted on the optical substrate.These elements preferably include at least one light source and an optical element, and for example an energy is produced grating, reverberator or the partial reflection device of a local oscillations field by light source light.Be installed in the detector that also has on the optical substrate, this detector is by the local oscillations field with from the optical illumination of the surface reflection of its relative motion to be measured.In this embodiment of the present invention, the optical path length that local oscillations field and measured surface are catoptrical makes two fields be concerned with at the detector place.
The 12 aspect according to some preferred embodiments of the invention obtains being parallel to the accurate measurement of surperficial motion perpendicular to the influence of the motion on surface and the influence of compensating measure device inclination by compensation.This aspect of the present invention is specially adapted to Computer Control Unit, for example computer mouse.
Like this, provide a kind of method of a surface with respect to the relative motion of measurement mechanism that be used for determining according to a preferred embodiment of the present invention, this method comprises:
With incident illumination optical illumination surface;
Detection obtains at least one detectable signal from the light of surface reflection; And
Determine to be parallel to the amount of the relative motion on surface according to above-mentioned at least one detectable signal, it is characterized by
Above-mentioned determine to comprise to correction perpendicular to the influence of the relative motion on surface.
Above-mentioned at least one signal preferably includes at least two signals, wherein at least one first signal is to be subjected to being parallel to the surface and perpendicular to the influence of the relative motion on surface, at least one secondary signal is what to be subjected to perpendicular to the influence of the motion on surface at least, and
Above-mentioned determine to comprise the amount of determining to be parallel to the relative motion on surface according to two signals.
Above-mentioned determine to preferably include:
Determine one first amount of relative motion according at least one signal in above-mentioned two signals, first amount of above-mentioned relative motion comprises a component and the component perpendicular to the surface that is parallel to the surface;
Determine one second amount of relative motion according at least one signal in above-mentioned two signals, second amount of above-mentioned relative motion comprises a component perpendicular to the surface; And
First amount and second according to determined relative motion is measured the amount of determining to be parallel to surperficial relative motion.
Second amount of relative motion does not preferably comprise the component that is parallel to the surface.
Second amount of relative motion preferably comprises a component that is parallel to the surface.
In a preferred embodiment of the invention, determine according to catoptrical Doppler shift perpendicular to the relative motion on surface.
In a preferred embodiment of the invention, above-mentioned determining comprises the relative motion amount of directly determining to be parallel to the surface according to two signals, and uncertain relative motion amount perpendicular to the surface.At least one secondary signal preferably is to be determined by the relative motion perpendicular to the surface basically.
In a preferred embodiment of the invention, at least one secondary signal is a signal based on Doppler shift.
At least one secondary signal is preferably relevant with the relative motion that is parallel to the surface.
In a preferred embodiment of the invention, this method comprises the amount of determining perpendicular to the relative motion on surface.
In a preferred embodiment of the invention, be parallel to the surface the relative motion amount determine to comprise the relative motion amount of determining along two non-colinear directions.
In a preferred embodiment of the invention, illumination light impinges perpendicularly on the surface.
In a preferred embodiment of the invention, above-mentioned detection comprises coherent detection.This method preferably includes from as the part reflection of the light of an object of a measurement mechanism part or be diffracted into the local oscillations field.This object is the reflecting object of a part preferably, and incident light or reflected light will be through them.Preferably incident light and reflected light all pass through this object.
In a preferred embodiment of the invention, this object is close to the surface.
In a preferred embodiment of the invention, the position, surface is in the near field of this object.Perhaps, the position, surface is in the outside in grating near field.
In a preferred embodiment of the invention, this object is a grating.This grating preferably only produces basically and is used for the single-stage transmitted light of illumination surface.
Illumination light preferably is partial coherence at least, and this object is placed in the coherent length scope of the light of surface reflection.
In a preferred embodiment of the invention, local oscillations light and reflected light incide at least one detector producing above-mentioned each signal, and local oscillations light and reflected light are partial coherences at the detector place at least.
A kind of equipment also is provided according to a preferred embodiment of the present invention, and it is used for measuring the relative motion between this equipment and the surface, and this equipment comprises:
A lighting source, it sends illumination light and comes illumination surface;
One first detector, it receives the light from light source from surface reflection;
An object, it reflexes to the part of illumination light on above-mentioned first detector, makes this detector according to surface reflection and coherent detection as the reflected by objects light of local oscillations light are produced one first signal;
One second detector, its receives the light that does not receive from the illumination of light source from surface reflection, and correspondingly produces a secondary signal;
A signal calibrator, it adjusts first signal according to secondary signal for the variation of illumination intensity; And
A motion calculator, it is according to the calculated signals relative motion from signal calibrator.
The illumination from light source that second detector is received is preferably reflected by object or the light of diffraction.
Signal calibrator is preferably proofreaied and correct a constant term in first signal according to secondary signal.Signal calibrator preferably contains a differential amplifier, and it receives first signal and therefrom deducts secondary signal, to produce first signal of an adjustment.Signal calibrator preferably contains a normalization device, first signal that its receive to be adjusted and with secondary signal to normalization.
In a preferred embodiment of the invention, this equipment comprises:
One the 3rd detector, its receives the light that does not receive from the light of surface reflection from object or light source, and correspondingly produces one the 3rd signal, and
Signal calibrator is proofreaied and correct first signal of adjustment according to the 3rd signal.
A kind of equipment also is provided according to a preferred embodiment of the present invention, has been used for measuring the relative motion between this equipment and the surface, this equipment comprises:
A lighting source, it sends the illumination light illumination surface;
One first detector, it receives the light from light source from surface reflection;
An object, it reflexes to a part of illumination light on first detector, makes this detector according to surface reflection and coherent detection as the reflected by objects light of local oscillations light are produced one first signal;
One second detector, its receives the light that does not receive from the light of light source from surface reflection, and correspondingly produces a secondary signal;
A signal calibrator, it deducts an amount that is proportional to secondary signal to first signal; And
A motion calculator, it is according to the calculated signals relative motion from signal calibrator.
The light from light source that is received by second detector is preferably reflected by object or the light of diffraction.
In a preferred embodiment of the invention, signal calibrator comprises a normalization device, and it adjusts first signal according to secondary signal for the variation of illumination intensity.
In a preferred embodiment of the invention, this equipment comprises:
One the 3rd detector, its receives the light that does not receive from the light of surface reflection from object or light source, and correspondingly produces one the 3rd signal, and
Signal calibrator is proofreaied and correct the signal of adjustment according to the 3rd signal.
A kind of equipment also is provided according to a preferred embodiment of the present invention, has been used for measuring the relative motion between this equipment and the surface, this equipment comprises:
A lighting source, it sends the illuminating bundle illumination surface;
One first detector, it receives the light from light source from surface reflection;
An object, it reflexes to a partial illumination light on above-mentioned first detector, makes this detector can be according to producing one first signal to the reflected light on surface with by the coherent detection as the light that object reflected of local oscillations light;
One second detector, its receives and not to receive from the light of surface reflection from object or from the light of light source, and correspondingly produces a secondary signal;
A signal calibrator, it deducts an amount that is proportional to secondary signal to first signal; And
A motion calculator, it calculates relative motion according to the signal from signal calibrator.
In a preferred embodiment of the invention, object is the part transmission, and is placed between lighting source and the surface, makes the light of illumination surface pass through object.
In a preferred embodiment of the invention, illumination light has a coherent length, and object and surface position are in above-mentioned coherent length.
In a preferred embodiment of the invention, object is a grating.This grating preferably only produces the single-stage transmitted light of illumination surface basically.Best position, surface is in the near field of grating.Perhaps, the position, surface is in the outside in grating near field.
In a preferred embodiment of the invention, the light of the light of surface reflection and object reflection is partial coherence at the first detector place at least.
According to a preferred embodiment of the present invention, also provide a kind of method of surface with respect to the motion of measurement mechanism that be used for determining, this method comprises:
With incident illumination optical illumination surface, make illumination light in the reflection of the several sections place on surface.
What utilization imported from incident illumination light is not coherently to survey light from surface reflection by the light of surface reflection as the local oscillations light beam, forms at least two signals thus;
Determine the size of the relative motion on surface according at least one signal in two signals;
The local oscillations light that changes at least a portion is with respect to the phase place of at least a portion from the light of surface reflection; And
According to the direction of determining to be parallel to surperficial relative motion by the characteristics of signals that relative phase caused of above-mentioned change.
Local oscillations light is preferably being produced as reflection on the object of a measurement mechanism part or refraction by incident illumination light.This object preferably is close to the surface.Illumination light preferably has a coherent length and object and position, surface within above-mentioned coherent length.This object is a grating preferably.This grating preferably only produces the single-stage transmitted light of illumination surface basically.The surface preferably is placed in the near field of grating.Perhaps, the surface is placed on the outside in grating near field.
In a preferred embodiment of the invention, above-mentioned change phase place comprises that importing a static phase changes, and above-mentioned phasing really comprises according to changing the direction that the characteristics of signals that is caused is determined relative motion by above-mentioned static phase travel direction.
In a preferred embodiment of the invention, this method comprises:
Photolysis from surface reflection is become first light and second light with second phase place with first phase place.
First light preferably has different polarization states with second light.
Above-mentioned decomposition preferably includes to allow incides lip-deep illumination light through a birefringent material.Perhaps, or additionally, above-mentioned decomposition comprises that the light that allows from surface reflection is through a birefringent material.This method preferably comprises a birefringent material is placed between object and the surface.
In a preferred embodiment of the invention, birefringent material is placed on will make the light that is detected pass through birefringent material twice between object and the surface.
In a preferred embodiment of the invention, this method comprises by utilizing two detectors that can produce the different signals relevant with translation direction to determine the size and Orientation of translation.The above-mentioned direction of moving that allocates really preferably includes according to the sign of the phase differential between the different detectable signals and determines direction.
This method preferably comprises to be made from the only linear polarization of surface reflection.
A kind of equipment also is provided according to a preferred embodiment of the present invention, and it is used for determining the translation of a surface with respect to this equipment, and this equipment comprises:
An optical unit;
A detector, it is combined on the optical unit, can produce a signal in response to inciding the light on it;
A lighting source, it can produce illumination light, and its part, is incided on the detector through behind the optical unit by surface reflection through optical unit again; And
A circuit, it is parallel to the size of the translation on surface according to above-mentioned calculated signals.
This equipment preferably comprises one and is positioned at optical unit or lip-deep object, it is the reflection of a part of illumination light or be diffracted on the detector but do not incide on the surface, above-mentioned part plays a part local oscillations light, by detector reflected light is carried out synchronizing detection.
A kind of method of a surface with respect to the relative motion of a measurement mechanism that be used for determining also is provided according to a preferred embodiment of the present invention, and this method comprises:
With incident light illumination surface, make the part reflection of illumination light from the surface;
Detection forms one first detectable signal from least one first of the light of surface reflection;
Detection forms one second detectable signal from least one second portion of the light of surface reflection; And
Determine the amount of relative motion according to catoptrical Doppler shift, wherein first and second signal is quadrature on phase place, and above-mentioned detection is that quadrature is surveyed.
This method preferably comprises the direction according to the above-mentioned first and second acquisition of signal relative motions.
This method preferably comprises determine to be parallel to the surface two the not relative motions on the conllinear direction.
This method preferably comprises to be determined perpendicular to the relative motion on the direction on surface.
The relative motion of this method is determined to preferably include at least one signal in above-mentioned first and second signals is carried out zero crossings counting.
Above-mentioned detection preferably includes coherent detection.
A kind of method of a surface with respect to the relative motion of a measurement mechanism that be used for determining also is provided according to a preferred embodiment of the present invention, and this method comprises:
With incident illumination optical illumination surface, make from the several sections indirect illumination light on surface;
Coherently survey light with a detector, form a signal from surface reflection;
The light that utilization is not gone out by the photoconduction of surface reflection from above-mentioned illumination light uses for above-mentioned coherent detection as local oscillations light; And
Determine the size of surperficial relative motion according to above-mentioned signal;
It is characterized by, local oscillations light is focused on the small size of detector, makes to have only catoptrical single spatial frequency composition just to form interference field with above-mentioned local oscillations light on detector substantially.
A kind of equipment also is provided according to a preferred embodiment of the present invention, has been used for determining the relative motion of a surface with respect to this equipment, this equipment comprises:
A housing that has an opening;
A detector in the housing, it can produce a signal that can be used to determine relative motion;
Laser lighting light source in the housing with setted wavelength, it makes to arrive detector from the light of surface reflection by opening by the opening illumination surface; And
A topped light filter on opening, it can see through the long light of given filter but stop the light of the wavelength of other detector sensitivities.
A kind of equipment also is provided according to a preferred embodiment of the present invention, has been used for determining the relative motion of a surface with respect to this equipment, this equipment comprises:
A housing that has an opening;
A detector in the housing, it can produce a signal that can be used to determine relative motion;
Laser lighting light source in the housing with setted wavelength, it makes to arrive detector from the light of surface reflection by opening by the opening illumination surface;
One second detector in the housing, it receives the light from surface reflection; And
A circuit, it will cut off lighting source when the light that receives when second detector is lower than a threshold value.
Light source can periodically be connected and cut off to this circuit preferably when the light that receives when second detector was lower than threshold value.
Opening preferably by topped with a light filter, it can see through to the light of wavelength but stop first and second detectors the light of responsive other wavelength.
In a preferred embodiment of the invention, a part of illumination light illumination detector rather than at first incide on the surface, the light of above-mentioned part plays a part local oscillations light, is used for detector to catoptrical coherent detection.
In a preferred embodiment of the invention, because above-mentioned translation, Doppler shift has taken place with respect to the light that is produced by light source in reflected light, and above-mentioned Doppler shift is used to determine motion.
A kind of equipment also is provided according to a preferred embodiment of the present invention, has been used for measuring the relative motion between this equipment and the surface, this equipment comprises:
A lighting source is used for illumination surface;
A detector, it receives light and a part of illumination light from light source from surface reflection, wherein do not contain by the above-mentioned part of surface reflection, make that detector can be according to producing a signal from the light of surface reflection with as the coherent detection of the illumination light part of local oscillations light, wherein above-mentioned signal has a frequency relevant with the speed of relative motion; And
A motion calculator, it can be according to the amount of the zero crossings number of signal being calculated relative motion.
Detector preferably comprises a Hi-pass filter, forms above-mentioned signal again after filtering is carried out in the output of detector.The slope of this Hi-pass filter is preferably less than about 20dB/octave (decibel/frequency multiplication).The preferably corresponding movement rate of the cutoff frequency of Hi-pass filter less than about 0.5mm/s.
This equipment preferably comprises:
One second detector, it can be surveyed from least one second portion of the light of surface reflection and not form second detectable signal that uses coherent detection, and
Motion detector is determined the amount of relative motion according to catoptrical Doppler shift, and wherein the signal and second detectable signal are quadrature on phase place, and surveys and comprise that quadrature surveys.
A kind of equipment also is provided according to a preferred embodiment of the present invention, has been used for determining the relative motion of a surface with respect to this equipment, this equipment comprises:
A housing that has an opening;
A detector in the housing, it can produce a signal that can be used to determine relative motion;
Laser lighting light source in the housing with a setted wavelength, it makes to arrive detector from the light of surface reflection by opening by the opening illumination surface; And
A circuit, it will cut off light source when the light that receives from the surface when detector is lower than a threshold value.
Light source can periodically be connected and cut off to this circuit preferably when the light that receives from the surface when detector was lower than threshold value.
A kind of method of a surface with respect to the relative motion of a measurement mechanism that be used for determining also is provided according to a preferred embodiment of the present invention, and this method comprises:
The part of a part transparent objects as measurement mechanism is placed near the surface;
With incident illumination optical illumination surface, make that wherein at least a portion of at least one light has been passed through object in incident light and the reflected light from the several sections reflected light on surface;
To produce a detectable signal, wherein object and surface are positioned in the distance less than the coherent length of surveying light from the light of surface reflection in detection; And
Determine to be parallel to the surperficial relative motion on surface according to detectable signal.The transmissivity of object spatially preferably changes.
In a preferred embodiment of the invention, object is partial reflection, and a part of incident illumination only reflected or diffraction by object, becomes reference illumination light, and utilizes above-mentioned reference illumination light coherently to carry out photodetection.
A kind of method of a surface with respect to the relative motion of a measurement mechanism that be used for determining is provided according to a preferred embodiment of the present invention, and this method comprises:
Partial reflection object as a measurement mechanism part is placed near the surface;
With incident illumination optical illumination object, make a part of incident light be reflected or diffraction by object, become a reference illumination light, another part is then by surface reflection;
Utilize reference illumination light that the light from surface reflection is carried out coherent detection, to produce a detectable signal; And
Determine to be parallel to the surperficial relative motion on surface according to detectable signal.
In a preferred embodiment of the invention, object is a part transparent objects, and at least a portion of at least one light has been passed through object in incident light and the reflected light.
The reflected by objects rate spatially preferably changes.This spatial variations preferably includes periodic spatial variations.
In a preferred embodiment of the invention, above-mentioned object is placed on comprises near the surface grating is placed near the surface.Above-mentioned a grating is placed on preferably include near the surface place grating sufficiently near the surface, make the position, surface in the near field of grating.Perhaps, an above-mentioned grating is placed on comprises near the surface and to place grating enough far from the surface, makes the position, surface outside the near field of grating.
In a preferred embodiment of the invention, the light that is detected is partial coherence at least.
A kind of method of a surface with respect to the relative motion of a measurement mechanism that be used for determining also is provided according to a preferred embodiment of the present invention, and this method comprises:
Grating as the part of measurement mechanism is placed near the surface;
With incident illumination optical illumination grating, make at least a portion illumination light incide on the surface and by surface reflection, wherein at least one light in incident light and the reflected light has passed through grating;
Utilize the light of reference illumination photodetection from surface reflection;
Produce a signal according to reflected light; And
Determine to be parallel to surperficial surperficial relative motion according to the signal that detects,
Wherein the position, surface is in the near field of grating.
From the light of surface reflection preferably with respect to being reflected by object or Doppler shift has taken place the light of diffraction, and the determining to comprise and determine to move of motion according to this frequency displacement.
The determining to preferably include of motion determined the variation of signal amplitude with the position.Motion is preferably determined by the zero crossings counting to detectable signal.
In a preferred embodiment of the invention, object has the asymmetric light transmission rate in space.This method preferably comprises the direction of determining relative motion according to the characteristics of signals that is caused by above-mentioned asymmetry.
A kind of method of a surface with respect to the relative motion of a measurement mechanism that be used for determining also is provided according to a preferred embodiment of the present invention, and this method comprises:
Part transparent objects as a measurement mechanism part is placed near the surface.
With the incident illumination optical illumination surface that does not constitute a conoscope image, make illumination light by the reflection of the several sections on surface, wherein at least a portion of at least one light in incident light and the reflected light has been passed through object;
Detection is from the light of surface reflection, and produces a detectable signal; And
Determine to be parallel to the surperficial relative motion on surface according to detectable signal.
This method preferably comprise change by the light of object reflection or diffraction and at least a portion from the phase place between the light of surface reflection.
A kind of method of a surface with respect to the relative motion of a measurement mechanism that be used for determining also is provided according to a preferred embodiment of the present invention, and this method also comprises:
With incident illumination optical illumination surface, make from the several sections indirect illumination light on surface;
Partial reflection object as the part of measurement mechanism is placed near the surface, and wherein part incident illumination light is reflected or diffraction by object, becomes reference light;
Utilization as local oscillations light, is coherently surveyed the light from surface reflection, to form a signal from the light of object reflection or diffraction;
Determine the relative motion on surface according to this signal;
Change at least a portion by the light of object reflection or diffraction with respect to the phase place of at least a portion from the light of surface reflection; And
According to the characteristics of signals that is caused by above-mentioned change relative phase, determine to be parallel to the direction of surperficial surperficial relative motion.
A reverberator is placed on is close to the surface and preferably includes a grating is placed near the surface.
In a preferred embodiment of the invention, change phase place and comprise the periodic variation phase place.
The direction of determining relative motion preferably includes the direction of determining relative motion according to the characteristics of signals that is caused by above-mentioned periodic variation phase place.
In a preferred embodiment of the invention, changing phase place comprises object is periodically moved along tested travel direction basically.
In a preferred embodiment of the invention, changing phase place comprises and makes object basically along periodically moving perpendicular to tested travel direction.
In a preferred embodiment of the invention, changing phase place comprises:
A transparent material is set between object and surface; And
This material powered up its optical length along illumination direction is changed.
Preferably a kind of piezoelectric of transparent material.
This method preferably comprises utilizes single detector to measure the size and Orientation of translation simultaneously.
In a preferred embodiment of the invention, change phase place and comprise that introducing a static phase changes, and the direction of definite relative motion comprises according to the direction of being determined relative motion by the characteristics of signals that above-mentioned phase change caused.
This method preferably comprises at least a portion is resolved into first light and second light with second phase place with first phase place at least from the light of surface reflection.First and second light preferably have different polarization states.Decompose to preferably include illumination light is incided on the surface through a birefringent material.This method preferably comprises the light that makes from surface reflection through a birefringent material.This method preferably comprises birefringent material is placed between object and the surface.
In a preferred embodiment of the invention, this method comprises the size and Orientation that the detector that utilizes two energy to produce different detectable signals according to the direction of translation is determined translation.
This method preferably comprises the direction of determining translation according to the sign of the phase differential between the different detectable signals.
A kind of method of a surface with respect to the relative motion of a measurement mechanism that be used for determining also is provided according to a preferred embodiment of the present invention, and this method comprises:
Reverberator that has opening as the part of measurement mechanism is placed near the surface;
With incident illumination optical illumination surface, make from the several sections indirect illumination light on surface, and illumination light is also contained the reverberator reflection or the diffraction of opening;
Utilization as local oscillations light, is coherently surveyed light from surface reflection to form a signal by the light of band open reflector reflection or diffraction;
According to this signal determine perpendicular to the surperficial relative motion that is parallel to the reverberator that contains opening.
Coherent detection preferably comprises:
Survey catoptrical amplitude or phase change; And
Survey catoptrical frequency displacement; And
Determine that relative motion preferably includes:
Change according in amplitude that detects or the phase change at least one and to come the relative motion of surface measurements on the direction that is parallel to the reverberator that contains opening; And
Come surface measurements perpendicular to the relative motion on the direction of open reflector according to the frequency displacement that detects.
This method preferably comprises:
Contain the reverberator of opening along periodically moving, increase the one-period phase shift with the light of giving reflection from it perpendicular to the direction on the surface that contains the opening catoptron; And
Utilize the motion of above-mentioned phase in-migration surface measurements.
A kind of method of a surface with respect to the relative motion of a measurement mechanism that be used for determining also is provided according to a preferred embodiment of the present invention, and this method comprises:
With a light illumination surface, its incident illumination makes from surperficial several sections towards a detector reflected light;
Reflected light is carried out spatial filtering, and making has linear relationship from the phase place substantially constant of the detection light of the last given scattered elements in surface or with the translation on surface;
Produce a signal by detector according to the light that incides on it; And
Determine the relative motion on surface according to this signal.
Illumination preferably includes the illumination light illumination surface with spatial variations.
Illumination surface preferably includes through one and is placed near surface and can comes illumination surface to light reflection or the reverberator that contains opening that is diffracted on the detector.Produce a signal and preferably include that utilization is reflected by the reverberator that contains opening or the light of diffraction comes the light from surface reflection is made coherent detection.
Determine that relative motion preferably includes and utilize catoptrical Doppler shift.
The light of illumination surface preferably collimates substantially, and spatial filter makes that to reflected light filtering having only catoptrical single spatial frequency composition to be detected device basically surveys.
The light of illumination surface preferably collimates substantially, and spatial filter makes and has only the surface reflection on the single direction just to be detected the device detection basically reflected light filtering.
In a preferred embodiment of the invention, spatial filtering comprises with lens that have a focus reflected light is focused on, and at the focus place of lens a pin hole is set.
In a preferred embodiment of the invention, spatial filtering comprises with lens that have a focus reflected light focused on, and at the focus place of lens a single-mode fiber is set, so that light is passed to detector.
In a preferred embodiment of the invention, spatial filtering comprises with lens reflected light is focused on, and at the picture place of light source a pin hole is set.
In a preferred embodiment of the invention, spatial filtering comprises with lens reflected light focused on, and at the picture place of light source a single-mode fiber is set, so that light is passed to detector.
A kind of method of a surface with respect to the relative motion of a measurement mechanism that be used for determining also is provided according to a preferred embodiment of the present invention, and this method comprises:
At least an object that has a quasi-continuous transmissivity distribution function is placed near the surface;
With incident illumination optical illumination surface, make surperficial several sections towards a detector reflected light;
Utilize the light of detector detection, to produce a signal from surface reflection; And
Determine the relative motion on surface according to this signal.
Object preferably has an asymmetric transmittance function; And definite relative motion comprises according to detectable signal determines travel direction.
By the light of object reflection or diffraction preferably towards detector; And survey is to utilize the coherent detection that is formed a signal by the light of object reflection or diffraction as local oscillations light.
A kind of method of a surface with respect to the relative motion of a measurement mechanism that be used for determining also is provided according to a preferred embodiment of the present invention, and this method comprises:
Through a reverberator illumination surface that contains opening, make that with illumination light the light of this illumination is not the picture of a last point in surface or a part from detector of optical illumination of surface reflection.
Use the reference light illumination detector of from above-mentioned incident illumination light, deriving simultaneously;
Utilize above-mentioned reference light coherently to survey reflected light on the detector, make detector produce a signal;
According to the surperficial relative motion of determining to be parallel to the surface by the signal change that relative motion caused.
Incident illumination light preferably has a given wavelength, and reference light also has same wavelength, makes that coherent detection is zero-difference detection.
This method preferably comprises and spatially changes lip-deep illumination.The lip-deep illumination of change preferably includes through a grating with spatial variations periodicity transmitance and comes illumination surface on the space.
The lip-deep illumination of change preferably includes through a grating and comes illumination surface on the space, and this grating can reflex to a part of light microscopic face that incides on it on detector, to form above-mentioned reference light.
A kind of method of a surface with respect to the relative motion of a measurement mechanism that be used for determining also is provided according to a preferred embodiment of the present invention, and this method comprises:
Use the illumination light illumination surface, make illumination light reflect from the several sections on surface;
A reverberator that contains opening is placed near the surface;
Utilization reflected by the reverberator that contains opening or the light of diffraction as local oscillations light, coherently survey light from surface reflection; And
Determine the relative motion of surface on the direction that is parallel to the surface according to the characteristic of signal.
Relative motion preferably utilizes to be surveyed from the Doppler shift of the light of surface reflection.
The reverberator that contains opening is a grating preferably, and is used to determine motion by the light of this optical grating diffraction.
In a preferred embodiment of the invention, illumination light be impinge perpendicularly on lip-deep.
In a preferred embodiment of the invention, the surface is the optics diffuse reflection surface
In a preferred embodiment of the invention, on the surface without any mark that can indicating positions.
Illumination light preferably includes visible light.Perhaps, illumination light comprises infrared light or comprises visible light and infrared light.
A kind of equipment also is provided according to a preferred embodiment of the present invention, has been used for determining the relative motion of a surface with respect to this equipment, this equipment also comprises:
Position is in the part transparent objects of near surface;
A detector, it can be surveyed and incide the light on it and produce a detectable signal;
A lighting source, it uses incident illumination optical illumination object, make object to detector reflection or diffraction illumination light, and the incident illumination light of a part reflected to detector by the surface, and detector utilize object to the light of its reflection or diffraction the light from surface reflection to be carried out coherent detection; And
A circuit, it according to detectable signal determine the surface with respect to equipment in the relative motion that is parallel on the surface direction.
A kind of optical mouse device also is provided according to a preferred embodiment of the present invention, and it comprises:
A housing that has one towards the opening on a surface; And
An optical motion detector, it monitors the surface by opening, wherein the optical motion detector utilizes method of the present invention to determine the translation of housing with respect to the surface.
A kind of touch indication device (touch point) as control device also is provided according to a preferred embodiment of the present invention, and it comprises:
A housing that has an opening; And
An optical detector, it determines the translation motion of finger on opening.
Optical detector preferably utilizes method of the present invention to determine translation.
A kind of pointer (pointer) device also is provided according to a preferred embodiment of the invention, and it comprises:
One according to the of the present invention first touch indication device and a circuit that removes to move a pointer in response to this indication device; And
A circuit that causes rolling according to the of the present invention second touch indication device and energy in response to this indication device.
A kind of Combined mouse device/touch indication device as computer pointer also is provided according to a preferred embodiment of the present invention, and it comprises:
A housing that has an opening;
An optical detector, it can determine the motion of a translation animal body on opening; And
Be used for determining that opening is towards the top or towards the device of below.
Optical detector preferably utilizes method of the present invention to determine translation.
A kind of scanner that is used for reading by the scanning motion of a scanner on a file this document also is provided according to a preferred embodiment of the present invention, and it comprises:
An optical pick-up head, it can survey the pattern on the paper surface; And
An optical detector, it can determine the motion of scanner at scanner during translation on paper surface, optical detector has wherein utilized method of the present invention to determine translation.
Pattern preferably includes printed patterns.Perhaps pattern preferably includes handwritten pattern or printed patterns and handwritten pattern.Perhaps, pattern preferably includes signature or above-mentioned pattern and signature.
A kind of scrambler also is provided according to a preferred embodiment of the present invention, and it comprises:
An optics diffuse reflection surface; And
Optical detector with respect to this apparent motion, wherein optical detector does not utilize the relative motion of lip-deep mark measurement with respect to the surface.
A kind of scrambler also is provided according to a preferred embodiment of the present invention, and it comprises:
An optics diffuse reflection surface does not have other marks except some reference markers on it; And
Optical detector with respect to this apparent motion, wherein optical detector is according to the relative motion of reference marker measurement with respect to the surface.
The surface is the disc surfaces around an axle rotation preferably, and the wherein rotation of detector measurement disk.
This scrambler preferably utilizes method of the present invention.
A kind of virtual pen also is provided according to a preferred embodiment of the invention, and it comprises:
One according to scrambler of the present invention; And
A circuit, it can convert to the above-mentioned relative motion that measures hand-written or graph data.
A kind of device that is used for mobile one page paper also is provided according to a preferred embodiment of the present invention, and it comprises:
Be used for the device of mobile paper; And
An optical detector, the motion that it can not utilize any mark on the paper to measure paper.
Optical detector preferably utilizes method of the present invention.
A kind of reader also is provided according to a preferred embodiment of the present invention, and it comprises:
One according to the device that is used for mobile paper of the present invention;
A reading head, it can be from sense information on the paper; And
A storer, its can according to the sheet movement that measures information stores in the relevant position of storer.
A kind of printer also is provided according to a preferred embodiment of the present invention, and it comprises:
One according to the device that is used for mobile paper of the present invention;
A storer, it contains the information of ready-to-print to the paper; And
A printhead, it can print corresponding information according to the sheet movement that measures.
A kind of facsimile recorder also is provided according to a preferred embodiment of the present invention, and it comprises one according to scanner of the present invention.
According to a preferred embodiment of the present invention a kind of facsimile recorder also is provided, it comprises one according to printer of the present invention.
A kind of method of a surface with respect to the direction of the relative motion of a measurement mechanism that be used for determining also is provided according to a preferred embodiment of the present invention, and this method comprises:
With incident illumination optical illumination surface, make surperficial several sections towards detector indirect illumination light;
Object with asymmetric transmissivity distribution function is placed near the detector place;
Utilize detector to survey light from surface reflection to produce a signal;
Determine the direction of surperficial relative motion according to this signal.
The simple declaration of accompanying drawing
To the explanation of some preferred embodiments of the invention, can more be expressly understood the present invention under reading in conjunction with the drawings, in the accompanying drawings:
Fig. 1 is the schematic diagram of a preferred embodiment of motion sensor in accordance with a preferred embodiment of the present invention;
Fig. 2 is the curve map of grating transmissivity distribution function in accordance with a preferred embodiment of the present invention;
Fig. 3 A, 3B, 3C are the schematic diagrams of the preferred embodiment of integrated form motion sensor according to some preferred embodiments of the invention;
Fig. 4 is the schematic diagram of optical mouse device in accordance with a preferred embodiment of the present invention;
Fig. 5 A and 5B are the schematic diagrams of Genius mouse/finger translation measurement device in accordance with a preferred embodiment of the present invention;
Fig. 6 is the schematic diagram of wand in accordance with a preferred embodiment of the present invention;
Fig. 7 is the figure of rotary encoder in accordance with a preferred embodiment of the present invention;
Fig. 8 is the schematic diagram of optical fiber type translation measurement device in accordance with a preferred embodiment of the present invention;
Fig. 9 is simplification and the general block scheme that is applicable to the electronic circuit of the preferred embodiment of the present invention;
Figure 10 is the reduced graph of the translation measurement device of another preferred embodiment according to the present invention;
Figure 11 A and 11B illustrate another preferred embodiment of the present invention;
In accordance with a preferred embodiment of the present invention one of Figure 12 A and 12B explanation utilizes the principle of the first preferred embodiment of the invention of the direction of motion that a mechanical switched system determines the translation measurement device;
Figure 13 A-13D explanation utilizes a mechanical switched system to determine the principle of two preferred embodiments in addition of the present invention of the direction of motion of translation measurement device;
Figure 14-16 explanation three kinds of unfavorable principles of using the translation measurement device of grating in accordance with a preferred embodiment of the present invention;
The other according to the preferred embodiment of the invention two kinds of principles of coming the motion detector of surface measurements motion based on Doppler shift of Figure 17 and 18 explanations;
Figure 19 A is schematically illustrated with the integrated morphology principle work identical with 16 apparatus shown with Figure 15 and that combine the orientation detection among Fig. 3 C, 17 and 18 with 19B;
The schematically illustrated details that is used in the detector module of some preferred embodiments of the invention of Figure 19 C and 19D;
Figure 20 A and 20B illustrate according to the preferred embodiment of the invention two views of general structure of the device of a rotation that is used for measuring a smaller axle;
Figure 21 schematically illustrated in accordance with a preferred embodiment of the present invention be applicable to a kind of detector layout of influence that reduces measurement to be parallel to the motion on surface perpendicular to the motion on surface;
Schematically illustrated the determining in accordance with a preferred embodiment of the present invention of Figure 22 A-22D along the range detector layout of the two dimensional motion of surface plane;
Figure 23 illustrates the cursor speed under the various filtering techniques and the relation curve of superficial velocity;
Figure 24 illustrates a kind of diffraction grating that is used for a preferred embodiment of the invention;
Figure 25 illustrates second kind of diffraction grating that is used for a preferred embodiment of the invention;
The position of Figure 26 A-26C explanation light source, detector and grating in accordance with a preferred embodiment of the present invention, wherein detector is away from the specular light on surface; And
Figure 27 is the electrical schematic diagram of a preferred embodiment of a self-adaptive band-pass filter circuit that is applicable to some embodiments of the invention.
The detailed description of some preferred embodiments of the invention
Fig. 1 illustrates the equipment 10 of the translation that is used for surface measurements 12 in accordance with a preferred embodiment of the present invention.Equipment 10 comprises that one is partial coherence at least, preferably sends the light source 14 of collimated light, for example a laser instrument.This laser instrument is a diode laser preferably, for example the miniwatt infrared laser.Though also can adopt other wavelength, thus since when high-power down work infrared light to eye-safe infrared laser preferably.This light source is preferably collimated.Wish with collimated light beam it is to consider from the angle of field depth, but collimation requirement also not really high.In addition, if carried out compensation as described below, also can use non-collimated light source.
Equipment 10 also contains an one dimension or a two-dimentional reflection grating 16 near surface 12.Distance limit between grating 16 and the surface 12 is as follows.Typically, this distance is several millimeters or littler.Before being surveyed by photo-detector 22,12 light that reflect preferably all are incident on the spatial filter (being made up of lens 18 and a pin hole 20) from the light of grating 16 reflections (or diffraction) with from the surface.The interference that obtains will produce a beat signal relevant with apparent motion.As shown in Figure 1, surface 12 is basically to all direction reflected light.In order to express clearly, these light in some drawings do not draw.
In Fig. 1, incident light is with an angle directive surface; But, might allow the direction incident of light with the normal of grating 16.In addition,, thereby utilized grating reflection light (or zero order diffracted light), can utilize the one-level or the more senior diffraction light of grating equally as local oscillations light though the incident angle of light equals search angle among Fig. 1.The advantage of zero level is that it is and Wavelength-independent (wavelength stable inessential).Incident light is pulse also continuous both.In Fig. 1 ,-1 and+1 order diffraction light respectively by code name 19 and 21 the representative.Represented by code name 17 by the light of surface scattering.
In preferred embodiment shown in Figure 1, determine tangential motion with no speckle coherent detection (zero balancing or process of heterodyning, shown in Fig. 1 is zero balancing).This detection intrinsic ground has the amplification of measuring-signal, causes high dynamic range.
The reference local oscillations field that is used for coherent detection is provided by the reflected light that is close to the grating 16 that moving surface places.Grating has produced an oscillator signal relevant with translation with the interference of light on detector of moving surface reflection.Grating reflection light near the surface is had a plurality of advantages as the source of local oscillations, wherein has following these advantages at least:
1, grating is the discrete component that combines the effect of beam splitter in coherent homodyne/heterodyne detection optical devices and catoptron, and this makes optical system simply, not be subject to disturb and the almost not requirement of aligning aspect.
2, when in the near field at grating, surface position, grating will carry out the intensity and/or the phase modulation (PM) of space periodicity to the light from surface reflection.This makes and can utilize specular light (zero order light) to survey translation as reference light.
3, can utilize the translation of the Doppler shift searching surface of surface reflection to senior (± 1 grade, ± 2 grades etc.) diffraction light of grating as the local oscillations field.The relevant phase shift with translation between the reference light of non-mirror reflection level time and the surface light will produce the oscillator signal of representing translation.Will increase for higher order of diffraction Sub-reso.
4, can cause frequency offset to carry out translation by mobile stop position (for example sawtooth wave modulation) periodically and survey, this makes the size that can not only determine translation, can also determine its direction.
5, two-dimensional grating can provide with reference to (local oscillations) light and to illumination surface with from the modulation of the light of surface reflection, thereby available discrete component carries out two two-dimensional transversal motion measurements on the quadrature translation direction.
6, measure the different components that inferior grating light not at the same level can provide surface translation or velocity.For example, for direct reflection, can be independent of other translation direction ground and measure along axial translation perpendicular to grating.This makes can realize the D translation measurement.
7, utilize appropriate signals to handle and analyze, asymmetric grating transmissivity distribution function (amplitude and/or phase place) makes the orientation detection that can carry out all orders of reflection time.
8, utilize the frequency offset that phase shift produced of local oscillations light, add the Modulation and Amplitude Modulation that cause in the grating near field, make available single detector measure two-dimension translational (in a horizontal or axial translated plane) simultaneously.
Except with the spatial filtering relative restrictions, the allowable distance between grating and the surface generally depends on grating cycle ∧, optical wavelength λ, the be concerned with angle of width Delta λ, lighting area and incident, folded light beam of spectrum.
Utilize the preferred embodiment of the present invention of the light of optical grating reflection or diffraction for those, wish that most distance between surface 12 and the grating 16 is less than the coherent length of light, promptly less than ≈ λ as local oscillations light
2/ Δ λ, wherein Δ λ is the spectral width (needing not be equal to the spectral width of light source) that arrives the light of detector.In addition, in order to keep the coherence on the diffracted beam width, the coherent length of light source preferably should be greater than n λ L/ ∧, and wherein L is the width of illuminating bundle.If desired, can arrive the spectrum composition of detector with restriction, and increase its coherent length by in light path, carrying out suitable spectral filtering.
Play the preferred embodiment of the present invention of main effect for those transmissivity distribution shapes modulated in detecting strategy, the spacing between grating and the surface 12 also must be at the distance of near field (the ≈ ∧ of grating
2/ 4 λ) in the scope.For following each embodiment, will suppose that this spacing belongs near field range.For the not really important situation of this point, this requirement can be relaxed.
The relative motion on surface can be measured with several different methods.Consider the following incident field and the transmittance function of grating, they are respectively:
E(t)＝E
0cos(ω
0t)
(1)
Suppose that grating is that one-period is the net amplitude type grating of ∧, so its transmissivity is the summation to non-negative space frequency, coefficient is a real number.Similarly expression formula also is applicable to two-value phase grating or some general phase grating, and they also can be used to implement the present invention.For amplitude and the so general situation of phase grating, need add a phase delay item.Simple in order to illustrate, the following description will be based on net amplitude type grating.But should be appreciated that, for certain embodiments of the invention, also can use other gratings, in addition more useful.In following mathematics manipulation, also omitted unessential constant factor in the each several part.
What suppose that light source throws light on area of raster is plane wave (being collimated light beam), but this is not strict essential, and non-collimation can be compensated in another part (for example spatial filter) of system.For simply, suppose that incident light is not perpendicular to grating (being like this among Fig. 1).The incident light (with respect to direction or its vertical direction of grating lines) that tilts will provide identical result basically, and just reflection angle changes to some extent.Like this, grid fields contains the order of diffraction time of a series of reflections, and they are symmetrically distributed with respect to direct reflection composition (zero level), and obeys angle condition (for the n level):
sin(α)＝nλ/Λ
(3)
As shown in Figure 1, a spatial filter that is positioned at detector the place ahead preferably is made up of a condenser lens 18 and a little pin hole 20 that is positioned at the lens focus place.This spatial filter preferably is conditioned to such an extent that only select spatial frequency composition and arrive detector.Pin hole can with one have similar core diameter and can photoconduction to one far the single-mode fiber of detector substitute.Spatial filter preferably is aligned to such an extent that can make some orders of diffraction arrive detector, and is as described below, and the light of this order of diffraction will be with the local oscillations light of opposing catoptrical homodyne or making up the difference and surveying.The local oscillations field is:
E
LO(t)＝E
ncos(ω
0t+
n)
(4)
From the mirror field that equidirectional is arranged with n order diffraction light of moving surface reflection by an integral representation, the illuminated surface area that limit of integration is made up of the many independent reflection elements on surface.By to the direction (y) that is parallel to the grating lines with to the integration perpendicular to the direction (corresponding to the light that penetrates in the surface) on surface, the expression formula that provides mirror field is:
Wherein r (x) is respectively surperficial amplitude reflectivity and the phase reflection rate relevant with the position with φ (x).Suppose that reflectivity and time are irrelevant in measuring process, and r and φ are the stochastic variables of position x.The translation that the surface is counted from its initial position is p (t), and p (0)=0.Periodic phase item 2 π nx/ ∧ result from the angle [alpha] (reflection of sin (α)=n λ/∧).Integration is limited to from x
1To x
2, they all depend on lighting area.
Integration variable is transformed to x-p (t) from x, and this is equivalent to the surface is regarded as static, and grating moves with respect to a reference frame:
(6)
The limit of integration becomes from x now
1-p (t) is to x
2-p (t), from but relevant with the time.A (x) is substituted with its Fourier series, and make φ n (x)=
φ (x)+2 π nx/ ∧ then has:
(7)
(optics) phase place of lip-deep scattered elements and translation p (t) have linear relationship, i.e. φ=φ n (x)+2 π np (t)/∧.For direct reflection (n=0), this phase place is a constant.
Mirror field and local oscillations field all arrive on the detector.Detector measurement be proportional to square intensity, its expression formula is:
I(t)＝(E
LO(t)+E
r(t))
2＝E
LO(t)
2+2E
LO(t)E
r(t)+E
r(t)
2
(8)
Suppose that the local oscillations field is much larger than mirror field; E
LO＞＞Er, and the integral time of detector much larger than light wave cycle but much smaller than ∧/nVmax (wherein max is a maximum detection speed).Integration to optical frequency will only provide a DC component, and other variable quantity then is a transient measurement.Under these hypothesis, first intensity item becomes a constant I
LO=0.5E
2 LO, the 3rd intensity item can be ignored, i.e. Ir=0.5Er
2=0.In the preferred embodiment of the present invention, because grating reflection light has only some specific very narrow levels inferior, the light that reflects from diffuse reflection surface then is scattered on the big angular range, so this expropriation of land of strength ratio of local oscillations field and mirror field is big.
Though following discussion has supposed that the 3rd is zero,, also promptly when not allowing the light of surface reflection combine, still might utilize the spatial transmission rate to modulate and measure translation with the reference light of anti-grid of grating or diffraction even only there be the 3rd.This can (if desired) accomplish by selecting the angle of a position between each raster stage is inferior.This has the advantage that can greatly relax alignment condition (only requiring that the light position is on the focal plane of spatial filter) really, but generally its precision is relatively poor and signal to noise ratio (S/N ratio) is less.
The local oscillations field plays a part a very strong amplifier in the phase one of acquisition of signal.From this respect, because the noise of local oscillations field will directly be transferred to detectable signal, so wish that strongly this noise is as best one can little.
The cross term that records equals:
I
s(t)＝E
ncos(ω
0t+
n)E
r(t)
(9)
In the sign of integration of oscillating field item cos (wot) shift-in Er (t), product to sum formula cos α cos β=0.5 (cos (alpha+beta)+cos (alpha-beta)) of using cosine will obtain one and double frequency of light wave (2 ω in the cosine term of formula (7) low order end
0) the intensity composition and another have the intensity item of gradual phase place.Because the time response of detector, the quick oscillation composition will on average become zero.Remaining signal is:
(10)
The exchange summation number and the sign of integration, each to the contribution with value is:
(11)
Suppose C
0, C
1＞＞{ C
m, m＞1}.This requirement can only concentrate on two items us in each harmonic term of grating, promptly on the item of m=0 and m=1.We can write out for these two items:
(12)
(13)
Now notice is only concentrated on some particular diffraction order time in the light wave of optical grating reflection and diffraction, promptly on the direction of n=0 (direct reflection) direction and n ± 1.
For the direct reflection item, the contribution of m=0 item is:
For an even brightness diffuse scattering surface, this will be near constant, and with
(15)
Wherein intensity I (t) and phase theta (t) are to corresponding to the integration of diffuse reflection surface in the stochastic variable of the amplitude at spatial frequency 1/ ∧ place and phase reflection.For the diffuse reflection surface of single reflection element greater than space wavelength ∧, contribution is from the border of particle; And, will strong contribution all be arranged to all spatial frequencys less than l/d for diffuse reflection surface with low particle size, wherein d is an average particle size particle size.
The rate of change of these " random walk " variablees depends on that { Xi} is replaced required (latter is relevant with the variation of above-mentioned integral domain again) τ α (x1-x2)/v=L/v averaging time by one group of new center to one group of given reflection kernel, wherein v is an instantaneous time speed, and L is the illuminated size of grating.If have a large amount of illuminated L of making of grating cycle＞＞∧, then will obtain having the statistics amplitude of slow variation and the quick oscillation of phase place.The error of translation measurement is proportional to ∧/L and irrelevant with speed.
In a word, for the direct reflection translation measurement:
1, the measuring-signal in the detector output vibrates with frequency v/ ∧.To directly provide measured value to the detection of this signal and zero crossings counting, the direction of supposing translation did not change in measurement period, and then each zero crossings is corresponding to the translation of Δ p=∧/2.
2, the amplitude of measuring-signal and phase place are the statistic ensemble summing values that slowly changes.The relative accuracy of measuring is proportional to ∧/L, and L is the raster size of illumination.
3, the spacing between surface and the grating preferably should be both less than the distance of near field (≈ ∧
2/ 4 λ), again less than coherent length (the ≈ ∧ of the light that arrives detector
2/ Δ λ).
Different with direct reflection, first order reflection light also has Doppler phase shift.Investigate m=0 once more, the contribution of 1 spatial frequency composition obtains:
(16)
The same suc as formula (15), utilize decomposition to the cosine term in the formula (16), obtain:
I
s，0(t)＝I
0(t)cos(2πp(t)/Λ+θ
0(t))
(18)
Expression formula to the m=1 item is carried out similar processing, and formula (17) becomes:
I
s，1(t)＝I
1(t)cos(4πp(t)/Λ÷θ
1(t))
(19)
Equation (19) has omitted the slow variable that is added on the average detector signal (" direct current " composition).To the analysis showed that of equation (16)-(19), if Co＞＞C1, then a signal zero intersects corresponding Δ p=∧/2.And if Co＜＜C1, the then corresponding Δ p=of zero crossings ∧/4.This result can be generalized to other orders of reflection n＞1, if promptly Co＞＞C1, then measuring-signal will be by np (t)/∧ vibration.For | n|＞1, C
1Be equivalent to the vibration in two side bands of Co vibration, as the Modulation and Amplitude Modulation of higher frequency signals.Notice that the m=0 item does not need Near Field, so must be greater than near field limit ≈ ∧ by handle to the fixed distance of moving surface
2/ 4 λ are (but preferably still less than coherent length ≈ λ
2/ Δ λ), the contribution of m=0 item will be occupied an leading position.Perhaps, though near field range, also preferably adopt Co＞＞the grating transmittance function of C1.
In a kind of preferred doppler mode work, utilize a grating that incident illumination light is produced the local oscillations field to the detector diffraction.But in transmitted light, equally also have some order of diffraction items (for example when using net amplitude type grating).These orders of diffraction time may even cause the multi-beam illumination to the surface in the outside, near field of grating, and also can be diffracted into multi-beam from the surface to the light of detector reflection.So each detector will detect a plurality of Doppler's compositions, each composition correspondence the combination of some transmissions and the order of reflection time and the interference of the local oscillations field of the detector that throws light on, and has formed " optics is harassed ".
Use single beam lighting surface in a preferred embodiment of the invention, thereby avoided above-mentioned " optics is harassed ".Similarly, wish that also light from surface reflection is not by optical grating diffraction.So, the non-zero order transmitted light of grating is minimized, preferably can eliminate these light.Diffraction grating preferably can produce each local oscillations field with at different levels times reflected light, and is designed to be and has only single transmission level time (also promptly use the single beam illumination surface, thereby do not constitute interference figure from the teeth outwards) basically.Also have, wish that light from surface reflection by grating directive detector the time, the forward direction diffraction does not take place.
Referring to Figure 24, wherein show an exemplary diffraction grating 800 that has embodied this principle.Suppose that this grating is a two-value phase grating in the medium that to be immersed in a refractive index be ns, its refractive index is ng.This grating preferably has some square grooves 802 that the degree of depth is h.For the illumination light 804 of normal incidence, be Pr=2ngh/ λ from the phase differential of the light of grating inside surface 806 reflection, and the relative phase difference of transmitted light beam 808 is Pt=(ng-ns) h/ λ.When being a natural number, Pt will obtain insignificant senior transmitted light, so minimum groove depth is h=λ (ng-ns).Simultaneously, reflection efficiency depends on catoptrical optical phase difference, and it is Pr=2ng/ (ng-ns) after the cancellation groove depth.If transmission one side of supposition grating is air (ns=1), and makes zero order reflection minimum (Pr=M+1/2, M are natural number), ng=(M+1/2)/(M-3/2) is arranged then.For example, if M=5, wavelength is 850nm, refractive index n g
1.57 the groove depth of then about 1.5 μ m will cause best back to diffraction efficiency with have only the zero level transmitted light ideally.
After Figure 25 illustrates making and has only the zero level transmitted light basically and have the first order at least to the another kind of method of the grating 810 of diffraction light.According to a preferred embodiment of the present invention, a phase type diffraction grating 812 is plated with a metal (or medium) layer 814, and this coating plays a part to have the partial reflection device of controlled reflection coefficient.This coating for example can be by the coating material sputter or be evaporated on the grating surface and make.The opposite side of coating 814 is with basic optical medium 816 fillings identical with grating material of refractive index.Way is easily; this material 816 can be a kind ofly grating to be bonded in a polarizer, a wave plate, or the optical cement on the cover glass sheet (representing with code name 818 among the figure); perhaps, also can be the epoxy resin binding member 816 and 818 of a die casting.
In this structure, any optical path difference that the grating pair transmitted light causes all will be by the corresponding light path difference in optical cement compensation, makes that the Wave-front phase in this composite structure outgoing place is not changed.So there is not the transmission level beyond the zero level basically.On the other hand, owing to, for example, different phase places is arranged, still can obtain the back to diffraction light at the inward flange 820 and outward flange 822 places of groove 802 in the different location of coating 814.
An advantage of method shown in Figure 25 is can easily control grating reflection (promptly the back is to diffraction) power and transmission power by the reflectivity and the transmissivity that change coating 814.This effect for example can be used for making signal to noise ratio (S/N ratio) maximum and light intensity is restricted to level to eye-safe.
The method of elimination grating transmission diffraction light shown in Figure 25 also is applicable to complicated PHASE DISTRIBUTION, is not confined to the two-value phase grating.It also can be applicable to those hope can control transmitted light and catoptrical diffraction lens and other diffraction optical elements independently.Can also utilize second diffraction or the refracting characteristic of position on another outside surface 824 of optical element to change transmitted light.
The frequency relevant with the Co oscillating field depends on laterally and the translational component (explanation of face as follows) of axial (vertical direction).Otherwise, pass through C
1The Modulation and Amplitude Modulation of composition then only depends on cross stream component.When the frequency of Co vibration was enough high, this frequency can be measured with the technology of above-mentioned relevant frequency, can measure the transverse translation component by surveying the Modulation and Amplitude Modulation frequency simultaneously.So just, can only realize two-dimension translational measurement (comprising motion, i.e. axial translation) perpendicular to surface plane with single detector.
By to reference signal frequency offset in addition, can make the ratio between carrier frequency and the Modulation and Amplitude Modulation frequency become big, thereby improve measuring accuracy and can survey the direction of translation.Also have, the specular light that utilizes grating makes and can clearly distinguish transverse translation component (being characterized by Modulation and Amplitude Modulation) and axial translation component (phase place or frequency displacement by carrier frequency characterize) as local oscillations light.
In addition, in order to survey the direction of transverse translation, can distribute in conjunction with the asymmetric transmissivity of phase shift and grating (for example zigzag).Perhaps, also can perhaps as below illustrating in greater detail, also can adopt static phase change by the orientation detection of mobile grating Shu Jinhang two dimension.
In essence, for each non-specular surface diffraction embodiment of the present invention, all be to have selected two quasi-plane waves to survey for detector.One of them ripple is from the n order diffraction of grating.Another plane wave then produces by select a plane wave (utilizing spatial filter) from surface reflection.
Can do following summary about the translation measurement that utilizes non-specular surface diffraction (distinct in order to discuss, as to suppose constant airspeed simultaneously):
1, the measuring-signal in the detector output is with frequency nv/ ∧ vibration, and wherein n is that the order of diffraction is inferior.To the detection of this signal and make the zero crossings counting and will directly provide the measured value of translation, suppose that the direction of translation in measuring process does not change, then each zero crossings is corresponding to the translation of ∧/2n.
2, the amplitude of measuring-signal and phase place are that the statistics that slowly changes is combined and value.The relative accuracy of measuring is proportional to ∧/nL, and wherein L is the illuminated size of grating, and this size is more preferably greater than n λ L/ ∧.
3, the spacing between surface and the grating preferably should be less than the coherent length λ of the light that arrives detector
2/ Δ λ.
Though time dependent absolute translational movement | P (t) can | very accurately measured, but its direction one of the most handy following method determine.
In a preferred embodiment of the invention, direction can be by adding that the additional phase in-migration is definite between with reference to (local oscillations light) field and mirror field.This additional phase shift for example can by allow grating towards or realize away from apparent motion.Do not incide lip-deep phase place because this motion can not change, thus from the field of surface reflection with aforesaid do not have different.Yet, because this and the relevant motion of pattern displacement d (t), the phase shift that the local oscillations field will obtain adding.
By making d (t) is the one-period sawtooth function, can accomplish to keep spacing between grating and the surface almost constant and introduce a fixing frequency displacement between mirror field and local oscillations field:
(20)
Wherein τ is the time cycle of sawtooth wave, and fixedly the sawtooth wave amplitude makes and can give the phase shift of the reflected light of the n order of diffraction with 2 π (or integral multiple of 2 π).Because the frequency displacement that this motion causes is τ
-1If keep τ
-1＞nv/ ∧ then can be according to the frequency τ of detector signal vibration
-1+ nv/ ∧ determines direction of motion for certain.Perhaps, by deducting simultaneously to oscillation frequency τ to the counting of the zero crossings in the detectable signal and count results
-1Count results also can directly determine translational movement (positive and negative can).
If sawtooth wave amplitude undesirable (promptly not corresponding to the integral multiple of wavelength) also still can be determined direction, just formula is comparatively complicated.Here used " sawtooth " this term has comprised this nonideal variation.
The another kind of method of introducing periodically phase shift between the mirror field on local oscillations field and surface is the optical path length between modulated grating and the surface.This preferably utilizes a transparent piezoelectric element that is arranged between grating and the surface to realize.
The another kind of symmetric method of destroying between the positive and negative relative translation for the detection translation direction is to adopt the grating that asymmetric transmittance function (amplitude and/or phase place) arranged.For simply, suppose that to compare raster size along the interval of translation direction very big with its lines, and by grating K the point-like scattered elements of having thrown light on.The scattered elements that enters or leave the field of illumination can be ignored (they will show as a noise factor in comprehensively handling).Through with (not having frequency displacement here) interference of local oscillations light and elimination after the frequency of light wave, the signal that obtains is:
R wherein
i, x
iAnd φ
iBe respectively reflectivity, position (during t=0) and the relative phase (with respect to local oscillations light) of scattered elements i.This tittle all is a stochastic variable for the diffuse reflection object.This expression formula of detector signal will be used for following orientation detection mechanism.
For direct reflection:
Suppose p (t)=vt, also promptly determine translation direction integral time interior surface velocity variation smaller.So the single order of received signal and second derivative are:
The structure of supposing A (x) makes
。I is clearly arranged under this particular case
s" (t)=η vI
s' (t)..So, can derive the size of point-to-point speed from the ratio of the single order of detector signal and second time derivative, the more important thing is that the sign that can derive point-to-point speed is the direction of translation.
If can not suppose integration at detection direction in period speed be constant, then can carry out differentiate to the translational movement of measuring (can obtain) by the higher detector of precision of zero crossings counting or another concurrent working.If only need know direction (rather than size of speed), then only need to judge that first order derivative has identical sign (a certain direction) that different sign (opposite direction) is still arranged with second derivative.Carried out remaking after the symbol detection to derivative a simple XOR (XOR) and visited and do and when η and V have contrary sign, to obtain " 1 ", when η and V jack per line, obtained " 0 ".
An example that satisfies the A (x) of constant derivative ratio is following such exponential function combination:
Above-mentioned distribution patterns repeats with cycle ∧.Clearly, as desired, the single order of this pattern and second order (in fact all exponent numbers) derivative have constant ratio η=-γ/∧.But, the singular point at ∧/2 integral multiple places will bring " noise " to measurement.Along with increasing of scattered elements number, these singular points will increase the probability of error, and this is because just occur a singular point as a dispersing element through out-of-date in received signal.Along with the orientation detection increase of integral time, can reduce the contribution of noise relatively.
Suppose that this distribution patterns is lip-deep illumination light intensity.So the requirement near field is measured translation strict when big or small than the direct reflection of only press n=0.The transmissivity that Fig. 2 illustrates a supposition distributes, wherein γ=5.Its implementation can be to allow grating that partial reflection/transmission property is arranged, and the amplitude transmission function as shown in Figure 2.
A looser requirement that distributes for transmissivity is that two derivatives have constant syntactics (that is, they are not proportional relations accurately, but the symbol of their ratio is constant) in whole distribution.At this moment still can guarantee orientation detection, but along with the increase of scattered elements number, the probability of error to be higher than afore-mentioned (even not having the factor of singular point) to single scattered elements.
Can make similar analysis for senior time diffraction (| n|＞＞1).For simply, moves with constant speed V in the supposition surface once more.Equation (21) can be regarded as each amplitude-modulated signal sum value that frequency is the carrier wave of nv/ ∧.
Suppose A (x) asymmetric (for example zig-zag) now.For | n|＞＞1, the envelope of detector signal will be when the translation of " just " direction and transmission function be complementary, when the translation of " bearing " direction and the mirror image of transmission function be complementary.So if the element number of loosing less (its ultimate value depends on raster stage time n), then translation direction can be by the symbology of the first order derivative of detector signal envelope.In addition, the size of envelope derivative is proportional to the size of point-to-point speed.
Asymmetric transmissivity distributes and makes energy measurement direction in speckle tests the speed.By one at random the speckle figure detector signal that produces after having passed through the filtering of grating of close detector that an intensity transmissivity is distributed as A (x), can be expressed as:
R wherein
iAnd x
iBe respectively the intensity and the position of i " speckle ", p (t) is the translation on surface, supposes constant airspeed, p (t)=vt, and then the time-derivative of detectable signal is:
Since intensity γ i be on the occasion of, so if dA/dx is a constant, the direction of the clear translation of the derivative table of detectable signal then.Such distribution can realize with serrate transmissivity distribution patterns.Point of discontinuity in the pattern has added noise to measurement, in order to limit the probability of error, needs to adopt suitable limit of integration.Movement velocity is determined by the oscillation frequency of detectable signal.
Certainly, as the refill component of OTM (optical translation measurement) device, also might utilize machinery or other device (for example accelerometer) is determined travel direction.
As described above, the fluctuating meeting of light source amplitude is directly transferred in the signal that receives by the local oscillations field.For making this minimum, will survey one according to a preferred embodiment of the present invention and be proportional to the signal of light source amplitude, and from detector signal, deduct the signal that records (be called " and compensation,, detector and " compensation " signal).The for example available following method of this detection realizes:
With a beam splitter (not needing accurate aligning) to the light beam of light source beam splitting, and the beam direction told compensation detector, perhaps
Arbitrary bundle photoconduction from a plurality of light beams of optical grating diffraction to the compensation detector, and is not carried out spatial filtering (but having tangible decay) to it.Way is to adopt not to be to be used for the raster stage that spatial filtering is measured easily, for example is used for spatial filtering to 1 grade and measures, and is used for the source noise compensation to 0 grade.
One or several compensation detector of one or several raster stage time guiding, and block light, as will describing in detail with reference to figure 19D from surface reflection with a polarizer.
The output of compensation detector is exaggerated (or decay), make when surface during (perhaps when " window " by an opaque cap covers time) difference signal not with respect to the device motion approach as far as possible zero, thereby compensate the fluctuating of local oscillations power.
Detected intensity shown in the formula (8) (with the detectable signal that obtains) comprises a local oscillations composition E
LD 2(E
o 2), a cross term E
oE
rAnd the reflection item Er of a secondary
2
For the variation of the coefficient Eo that compensates the Er composition, the control voltage of the controllable gain amplifier of a certain amplifier stage (is deducting Eo in can amplifying the signal of compensation detector as signal
2After the compensation first time of composition).This gain should be similar to the square root that is inversely proportional to compensating signal.
In order to obtain the highest signal quality, preferably also to compensate Er
2Come the catoptrical embodiment of the invention of spatial filtering surface for those uses " equivalent pinhole " (below will illustrate), this may be useful especially.In this embodiment, to Er
2Composition carries out the detector exposure area of integration can be much larger than the area of " equivalent pinhole ".Er
2Composition can not be that the detector of surveying the local oscillations field compensates with one.The compensation detector can be placed on basically without any raster stage time irradiation place thereon.Perhaps, also can only survey the polarized light that has in fact blocked the local oscillations field.This for example can realize by place a polarizer in the detector front.
Er
2The variation of composition is generally changed by lip-deep contrast and causes that this for example results from again to different colours reflection of light coefficient difference.But, the reflectivity on high reflectance surface (for example multi-ply paper) also changes responsive near the small reflection angle the specular angle, shown in Figure 26 A, simple for what illustrate, shown in Figure 26 A-26C is the situation of light source 832 vertical illumination gratings 830, in addition, except surface 836, only show a detector 834.In order to reduce Er
2The variation of composition preferably must make light source and detector arrangement the latter be away from surperficial direct reflection, shown in Figure 26 B.Perhaps, can avoid the direct reflection of surface with respect to surface plane to the detector direction inclination several years by making grating, shown in Figure 26 C to detector.But must consider the influence of pitch angle to Doppler shift.Preferably utilize Z component (for example illustrated) obviously to reduce to measure susceptibility to the pitch angle precision with reference to Figure 21.
Fig. 3 A illustrates a preferred embodiment of translation detector in accordance with a preferred embodiment of the present invention, wherein utilized the zero order light detection and do not had orientation detection, perhaps orientation detection wherein utilizes asymmetric grating transmissivity to distribute and adds that the appropriate signals analysis realizes.Shown in Fig. 3 A is a kind of integrated optics chip that is suitable for producing in batches or translating device 30.It only adopted a small amount of can be with a large amount of elements of making of low cost.Device 30 contains a laser diode 32, and it is a single-transverse mode laser preferably.The light that sends from laser diode 32 is preferably collimated by lens 34, the preferably etching or be deposited on the lip-deep diffraction type collimation lens of a glass, quartzy and so on optical chip substrate 36 of these lens 34, its both sides preferably also are coated with antireflective coating except some appointed areas.The grating 38 that in optical chip substrate 36, also has an amplitude and/or phase type.The preferably etching or be deposited on the lower surface of substrate 36 of this grating 38., and focused on again by two reflectings surface 40 and 41 reflections by the light of grating and surface 42 reflections by lens 44, these lens 44 preferably one be etched in substrate 36 lip-deep reflection diffraction type condenser lenses.Light face 45 reflection that is reflected again.Reflection/46 of light blocking layer pin hole that are formed on the focus place of lens 44 allows the reflected light from plane wave on surface 42 and grating 38 lead to a detector 50, and this detector 50 for example is a PIN type photodiode or similar device.Be preferably in lens 44 back and place a compensation detector 52, survey the light of a part from grating 38 reflections.Utilize a controller 54 to determine the translation or the speed on surface, this controller 54 comprises a laser diode drive/modulator that is used for exciting laser diode 32, surveys amplifier, and zero crossings counting circuit or frequency sonding device.Compensation detector 52 provides a compensating signal that is proportional to the local oscillations light amplitude, is used for reducing any residual action that laser instrument output changes.In order to reduce noise, the most handy dual-hinge line, shielding line or coaxial cable deliver biography to the signal that comes self-controller 54, in order to prevent to damage grating 38 and to keep the good constancy of grating and surface spacing, this equipment preferably is provided with and can allows it be placed on several pin or annular mount or similar bearing on surperficial 42.
Fig. 3 B illustrates another preferred embodiment of the present invention, and it has comprised to utilize surveys the phase shift of local oscillations field and the first-order diffraction direction of light of grating.Represent with identical code name with the element that Fig. 3 A plays same function among the figure that in the device shown in Fig. 3 B 60, the light that sends from laser diode 32 is by lens 62 collimations, directive grating 38.Grating 38 preferably is installed on the piezoelectric ring 64, and the latter is installed in again on the optical substrate 36.As mentioned above, for travel direction is surveyed, but excitation rings 64 comes local oscillations field (from the light of grating 38 diffraction) is added a variable phase place.In the embodiment shown in Fig. 3 B, the signal that is used for translation and orientation detection utilizes the first-order diffraction light of grating 38 to survey with the signal both who is used to compensate, and just their sign is opposite.Be preferably in suitable place and all plate antireflective coating, to reduce undesirable reflection.
Because integrated optics chip can be made at low cost in a large number, so it is a kind of preferred scheme.Only show a detector among the figure and be used for single direction, preferably also measure its orthogonal directions with second detector.All optical element one lens, grating, catoptron, pin holes one all are etchings or are deposited on the optical substrate, and according to its function can be reflection or transmission.Discrete component one laser instrument, detector and piezoelectric sensor one in the system is installed in the top of chip.The top of chip also can be made or be installed in to each electronic component of controller 54.
Should be appreciated that each feature of Fig. 3 A and 3B can mix and combine.For example, for example encircle on 64 such sensors if in Fig. 3 A grating 38 is installed in one, then this device can work in direct reflection (zero level) pattern and increase dynamic range, also might additionally survey axial translation.In addition, might come the grating 38 of alternate figures 3B and ring 64 to survey with an asymmetric grating with travel direction.For these and other preferred embodiments of the present invention, those skilled in the art that can be in conjunction with various characteristics of the present invention.
Fig. 3 C illustrate in accordance with a preferred embodiment of the present invention another determine the method for direction.The device 70 of Fig. 3 C is similar with the device 60 of Fig. 3 B, and just grating 38 is set on the lower surface of chip 36 here, and has replaced piezoelectric ring 64 with birefringent plate 66.Light source 32 produces the linearly polarized light at the birefringence axis direction angle at 45 of polarization direction and plate 66.To comprise two light waves from twice of the light of surface reflection through behind the plate 66, all there is 45 ° angle their polarization direction with polarisation of light direction from grating 38 reflections or diffraction.The phase differential of these two light waves is 90 ° under the ideal case.
In addition, be preferably in detector 50 fronts and place a polarization beam apparatus 68.Its optical axis makes a polarization composition to detector 50 transmissions, and the polarization composition of quadrature is then to detector 67 reflections.Have, beam splitter 68 is respectively half guide probe 50 and 67 from the light of grating 38 reflection or diffraction again.The signal that is detected by detector 67 and 50 will have 90 ° phase differential.The sign of this phase differential can be used for determining travel direction.
Perhaps also can place the polarizer of mutually orthogonal simultaneously respectively two detector fronts with a part reflective mirror the light separated into two parts, thereby two kinds of polarization states separately.
The illumination light of grating preferably collimates.But also can use uncollimated illumination light, at this moment grating diffration light will be (the no longer existing single focal plane) that astigmatism is arranged.Preferably can compensate this effect so that the spatial filtering best results.Way is the astigmatism that one or several lens of design come calibration grating easily.Perhaps, or additionally, grating self can be designed to be and contain astigmatic correction.In other diffraction elements that thrown light on by non-collimated light, also can expect to have similar effect of astigmatism and correction.
Though illustrated the present invention uses to solve general translation measurement problem in the various embodiments described above, its method also is applicable to production in enormous quantities.The optics cursor control device (Genius mouse) that a special applications of optical translation measurement method of the present invention is a kind of novelty, it is from any diffuse reflection surface almost, for example paper or desktop, on motion derive its translation information.This Design of device in accordance with a preferred embodiment of the present invention is shown in Fig. 4.An optical mouse device 80 contains " optical chip " 82, it preferably one for example be device 30,60,70, or the device of their variant.Chip 82 is installed in the housing 84, and monitors paper 42 by the open optical 86 on 84.The lead-in wire of chip 82 preferably is connected on a P.e.c. (PC) plate 88 or the similar device, and the electronic circuit 90 corresponding to the controller of device 30,60 or 70 has been installed above the latter.Be installed in one or several switch 92 on the PC plate 88, the same as with the common mouse device one or several button 94 excitations.This Genius mouse is as being connected on the computing machine with a cable 96 or wireless mode usually.
Above-mentioned measuring method in accordance with a preferred embodiment of the present invention allows the point-to-point speed of broad dynamic range, has covered the required scope of normal Genius mouse operation.This apparatus features makes it can be described as one " linerless optical mouse device ", and it can provide the pair of orthogonal signal that cursor is moved around in response to the motion on any enough irreflexive surface (for example paper or desktop) on display screen.So no longer need specific contrast mark or pattern.
Usually, mouse system utilizes mechanical pick-up device to measure the motion of staff on a surface (generally being one " mouse liner ").Generally acknowledged now and need in mouse system, adopt a kind of movement-less part, reliable, accurate translation measurement technology.Develop some optical devices, but still had various shortcomings, for example needed the liner of fine pattern, low sensing capabilities or high cost.
Optics linerless Genius mouse in accordance with a preferred embodiment of the present invention can be pressed dual mode according to user's convenience and use.It can be used as " routine " " Genius mouse ", and at this moment Genius mouse moves above the surface at one, and measures its motion with respect to the surface.It also can be tunked when wishing, just substitutes with the opening moveable finger along device.It will measure finger after static with respect to the motion of Genius mouse housing.
Fig. 5 A and 5B show a kind of such device 100.Fig. 5 A shows the formation of this device similar to Fig. 4 device (for the ease of relatively, having used same code name among these two figure), just 94 sides at housing 84 of button in device 100.Under the pattern shown in Fig. 5 A, device 100 is static, is used for following the tracks of the operator and points 102 motion.Very clear, device 100 can be turned around as a Genius mouse, and the Genius mouse with Fig. 4 is identical in many aspects.Fig. 5 B illustrates the skeleton view of this device, and an optional switch 104 is arranged as can be seen, and it is to be used as common Genius mouse or to work in the pattern shown in Fig. 5 A and the 5B that this switch is used to refer to device 100.Perhaps, this switch can be the gravity switch that is installed in the device, automatically a translative mode.Because for two kinds of patterns, the direction of motion of cursor is opposite, and general desirable sensitivity is also different, so general hope knows what pattern device is operated on.
In addition, as in the present invention, utilize to have the translation measurement device of a little opening and allow finger, just can come moving cursor by the translation of measuring finger as the touch pads along its harness motion.This function can be called " touch and give directions ", and it also can be used for giving directions the meticulous position on the keyboard.Except being installed in optical chip on the keyboard as switch, this device is identical with Fig. 5 device.Also have, also can use OTM " touch indication device " at the top of Genius mouse, to substitute scroll wheel.For example " kowtow and hit " and can be detected by finger is moved into and shifts out the touch point scope.
This device can be used for substituting the pointing device outside the Genius mouse, for example is used for the pointing device of above-knee or palmtop computer.Utilize this device can control the motion of any one dimension or two dimension in principle.
What at present, the laptop computer pointing device used is tracking ball, touch pads, trace point (nipple) or an attached Genius mouse.These devices have various shortcomings.Particularly, tracking ball is as the easy dust stratification dirt of conventional Genius mouse, and touch pads is abandoned by many users humidity sensitive, and migration but takes place should be static the time trace point, and Genius mouse is then relatively more fragile and need working top.
The size of touch pointing device is little, and its work bore can be less than 1mm
2, and high resolving power can be provided and big dynamic range is arranged.It is located at the ideal solution of the pointing device in the laptop computer in being.By some be similar to use touch pads like that on opening surface moveable finger just can operate this device.Its difference is that the size of opening is more much smaller than touch pads, and it does not exist humidity and moist and so on problem, can expect that it has high reliability.In fact, can be easily in single above-knee or palmtop computer, several touch pointing devices be set, be installed on the key, between key or on the screen limit.In addition, the pressure sensitive device also can be comprised in the touch pointing device, the sensitivity of touch point can do can be in response to the pressure of finger on the touch point.
Be provided with two in a preferred embodiment of the invention and touch the indication device, first touches gives directions device and circuit thereof that a pointer is moved in response to it, and second touch gives directions device and circuit thereof that screen is rolled in response to them.
In another preferred embodiment of the present invention, the present invention can be used as the improvement type translation and/or the velocity measuring system of a wand, it can scan each row of a text (or any pattern) and store them, is provided with the back download and gives a PC and/or utilize OCR software to convert ASCII character to.Fig. 6 illustrates an example of this device.Wand 120 comprises: " a reading " head that has an one dimension or 122 and lens 123 of 2 D photoelectric detector array (for example CCID array), its width is enough to scan a typical line height, and one with common light pen in identical light source 124.The reading head of pen also contains one and is used for measuring reading head in the translation that is scanned on the paper according to optical translation measurement of the present invention system 82, may also contain another translation measurement system and extract rotation information.This energy or a row that scans are as a bit diagram file storage (being suitable for handwritten word or figure or the like), perhaps by using inner OCR algorithm that scan line is translated into binary file immediately then.Canned data can be downloaded afterwards to computing machine, palmtop computer, telephone set or the like.Power and control for this purpose with to the various devices in the pen 120, a controller or microprocessor 128 and battery 129 also are provided.
Optical translation measurement method of the present invention makes device that little size, easy to use and accurate can be arranged.Cause the high reason of precision to be to compare with present mechanical mouse, method of the present invention has intrinsic high precision and is easy to carry out two dimension or three-dimensional measurement.At present similarly commodity device is in order to measure translation by the roll angle of surveying a band pattern wheel, needs to make it scanning when being scanned the surface and roll in that this wheel is pressed to.This technology can only be surveyed the position that can not survey along the position of a row along its vertical direction, and its lower accuracy limitations its range of application.
Another advantageous applications of optical translation method and apparatus of the present invention is a kind of scan word and it is passed to the portable or stationary installation of a Verification System of being used for.Similar to the principle of wand, the signature reader also contains a signature that has a dimension or 2 D photoelectric detector array (for example ccd array) " reads " head.For can the read-around ratio broad or than higher signature, it has an opening wideer than wand, and contain and be used for surveying hand or make device at the optical translation measurement device that is scanned the translation of instrument on both direction of moving in the signature.The signature reader does not contain any OCR, and this is not produce because do not have text.But, it but connects (connecting by the wired or wireless connection of hardware or by an off-line system) in one " authentication center ", judges its true and false by the signature that scans is compared with one " standard signature " there.This device can reach accurate, small-sized and be easy to and use when cost is low.
Another application of aforementioned means and method is the scrambler field.The present invention can substitute linear encoder and the angular encoder that the high-precision mark need be arranged with a scrambler that does not need mark basically on a code wheel or surface.Fig. 7 illustrates this a kind of angular encoder 130 on the one hand according to the present invention.Scrambler 130 contains a disk that has diffuse reflection surface 132 that is installed on the axle 131.It also contains preferably basically as hereinbefore optical chip 82 and controller 90.Preferably done one or two radial markings 136 on the surface 132, be used as the reference marker of scrambler and be used for correction error, this error occurs in the time of may reading angle in rotating a circle, and this mark can be read by optical chip 82, perhaps with one independently detector read.
The motion on the surface of being thrown light on by chip 82 can regard as the common translation tangentially of all scattered elements and angular velocity in the illuminated part with surface 132 rotatablely move combine.The size of lighting area makes the composition that all curvature caused to ignore preferably less than the distance to rotation center.Perhaps, under non-Doppler's mode of operation, preferably use a grating, the feasible measurement that can substitute the parity price surface translation with the direct measurement of diagonal displacement with even angle pitch.
An alternative embodiment of the invention is a kind of virtual pen, just a kind of pen that can become the movement conversion on a blank sheet of paper position readings.These position readings can be become virtual writing by a machine translation again, and this writing can be revealed, and also can be converted into letter or phrase.Computing machine can be stored this virtual writing with ASCII character then.To the transmission of computing machine can be online (utilizing the wired or preferably wireless connection to computing machine), also can be off-line, and under offline scenario, code or position readings are stored in earlier in virtual " pen ", waits to write to be transferred to computing machine again after finishing.This embodiment of the present invention provides a kind of compactness, no paper and noiseless pen recorder.
In a typical fax/printer, paper is moved with respect to write head with constant speed by a precision electric motor.Pencil with the paper pace mutually coordinated mode provide print data line by line, this method is a not only costliness but also coarse, the former is because it needs accurate motor and physical construction, the latter is because paper can skid in device sometimes, make the translation of paper no longer coordinate, thereby some no markings of going or twisted occur with printing equipment.
After having used the optical translation measurement device, might by measure online paper before come in to detect its slip.Control the work of printing equipment then according to the actual translational movement of paper, so just can obtain high precision but system cheaply.Similarly, this principle also can be applicable to the desk top scanning with hand device, has wherein just replaced printhead with reading head.In addition, according to the characteristic that detects signal, the type that can discern paper or other surfaces (for example cloth) can be arranged also.The feature that can be used for discerning paper type has: the ratio of reflected light AC and DC composition power, the absolute value of AC and DC power, harmonic ratio or the like, or the combination of these features.Also have, for the multiple situation of presenting, this measurement mechanism can be surveyed the uncontinuity of paper thickness.This uncontinuity can be determined with following method: axial translation is measured, obviously discontinuous in the cross measure value, the perhaps dropout that causes because of the coherence who temporarily loses between reflected light and the local oscillations light.
Fig. 8 is a kind of schematic diagram of motion detector, and it is applicable to scanner, and facsimile recorder or printer etc. only contains the device of motion in one dimension, and motion detector 200 contains a light source 202, and the light that it sends sends a housing 204 to by an optical fiber cable 205.The output light of optical cable 205 is collimated by lens 206, then by a grating 210 illumination moving surfaces 208.Received by the optical fiber cable 212 of a position from the light of grating 210 and surface 208 reflections in lens 206 focuses.The output of optical cable 212 is transmitted to a detector 214, to do aforesaid further processing.
In a preference file scanner embodiment of the present invention, the relative motion that this motion detector does not advantageously utilize any typographic(al) mark on the file to measure file has a reading head to read printing information on the file simultaneously.A storer receives from the information of reading head and it and is stored in the place, address that moves corresponding to the file that records.
In a preferred printer embodiment of the present invention, this motion detector is measured the motion of the paper that will print thereon, and other has a storer according to wherein sending print command corresponding to the information of the sheet movement that measures.
Preferred scanner of the present invention and printer can all be used for facsimile recorder according to the preferred embodiment of the invention.
Motion detector of the present invention can also be used to measuring the various motions in CD (compact disk) and the magnetic media storer.
Fig. 9 is the simplified block diagram of a useful exemplary electronic circuit 140 when enforcement is of the present invention." master " photodetector 142 (for example corresponding to the detector among Fig. 3 A and the 3B 50) receives aforesaid light signal.This detector is surveyed light, and the signal that obtains preferably passes through the amplification of amplifier 144, and the bandpass filtering of wave filter 146, and the amplification once more of amplifier 148 produce " master " signal.Compensating signal is for example surveyed by photodetector 150 (corresponding to the detector 52 among Fig. 3 A one 3C), after the amplification of process amplifier 152 and the bandpass filtering of wave filter 154, in differential amplifier 155, deducted, to remove the residue low frequency composition in the main signal by " master " signal.Bandpass filter 154 is preferably identical with 146.The voltage-controlled amplifier 150 that the difference signal that obtains is controlled by the output of low-pass filter 153 (it is by attenuator 158 decay that can regulate when the system calibrating) by a gain amplifies.The output of amplifier 156 is transmitted to a zero crossings detector sum counter 160 and direction control logic circuit 162, and the latter will determine the direction of surface translation.If used piezoelectric element 64 (Fig. 3 B), then will provide a control signal to direction control logic circuit 162 corresponding to the element displacement frequency, by this circuit it is deducted from the count value of zero crossings detector.
For the preferred embodiments of the present invention, the wavelength of LASER Light Source is preferably in region of ultra-red, for example is 1550nm.For diode laser, typical accessible spectral width is 2nm.Typically, the bore of grating is 1.5mm * 1.5mm, and grating frequency is 150 lines per millimeters.Typically, become the light beam that a beam diameter is slightly smaller than 1.5mm after the output of LASER Light Source is collimated, and being that 30 ° angle incides on the grating with respect to the grating normal.Optical substrate can have any thickness easily.But typically this thickness is several millimeters, and the focal length of used lens designs by aforementioned focusing requirement, and its representative value is several millimeters.Pin hole 46 (Fig. 3 A-3C) diameter is several microns, typically is 10 μ m.Should be appreciated that, above-mentioned these typical sizes and characteristic effect only for reference, other parameters in using according to employed wavelength and optical chip different, they can change in the larger context.
In some preferred embodiment of the present invention, pin hole is substituted by one " equivalent pinhole ".This equivalent pinhole is by the local oscillations field, for example from the light of optical grating reflection or diffraction, focuses on and obtains on the detector.Like this, only just obtain amplifying at the focal spot of local oscillations field light from surface reflection.So for example the pin hole 46 among Fig. 3 A, 3B, the 3C can be cancelled, simultaneously the local oscillations field is focused on the detector surface.
The intensity distributions that focuses on the local oscillations field on the detector has determined the amplification situation of signal field on the same position.So the enlargement factor of the ground square signal that the local oscillations field strength is big is big, and the little local enlargement factor of intensity is little.Thereby the focal beam spot on the detector surface played with " standard " spatial filter in the identical effect of vacuum pin hole.The quality of local oscillations field space distribution, i.e. it and the diffraction limit approaching degree that distributes has determined the quality of last spatial filtering.Focus on diffraction limit local oscillations field on the detector and farthest utilized amplifying power, and different, to the quality of theta alignment and insensitive with true pin hole to signal.Exempted in this way after " physics " pin hole, the interference free performance of device improves, and promptly relatively is insensitive to mechanical vibration, and looser theta alignment tolerance and higher overall magnification are arranged.Different with actual pin hole, the flashlight that is not exaggerated is not to be blocked, but since it a little less than than the local oscillations field make its influence to ignore to measurement more.This device is also more insensitive to focusing error.
It is insensitive to the variation of optical source wavelength using the advantage of equivalent pinhole layout in utilizing the Doppler measurement of grating, and the direction of local oscillations field is relevant with wavelength in this measurement.Wavelength change will cause the respective change at optical grating reflection angle, make the picture in the local oscillations source on the detector be moved.If use true pin hole, this will influence the signal amplitude that records, even causes losing fully of signal.After using pin hole of equal value, as long as focus on detector, just can not influence measured value.In addition, as the front about discussion based on the system of grating, detectable signal and Wavelength-independent in grating one reverberator layout, and time relevant with the order of reflection of translational movement, grating cycle and local oscillations.
Figure 10 illustrates a preferred embodiment of the layout that directly focuses on the detector.Simple in order to illustrate, shown in the figure is an one-dimensional measurement device, and does not wherein contain the orientation detection parts that had in the standard electronic subassembly (T05 etc.).This measuring appliance contain one for example laser diode etc. be at least the light source 250 of partial polarization, lens 252,256, one housings 258 of 254, one detectors of grating (for example PIN diode) are to outer lead 260 and electronic circuit 262.Laser diode 250 and detector 256 are preferably in and are arranged in same plane on the optics, and this plane is the focal plane of lens 252 preferably.The zero order light reflected of grating 254 is focused on the surface of detector 256, as the local oscillations field.If laser diode 250 and detector 256 is different to the distance of lens, then as the front about as described in the going through of the embodiment that uses non-collimated light source and package space wave filter, the layout here should make laser instrument by lens imaging on detector surface.Though among Figure 10 embodiment He among following embodiment orientation detection is not shown, the orientation detection of aforementioned (or aftermentioned) is still applicable to these embodiment.
For the measuring appliance that utilizes one-level (or more senior) diffraction light as the local oscillations field, its course of work is similar.Just layout is slightly different.Figure 11 A and 11B illustrate a kind of such layout in accordance with a preferred embodiment of the present invention.Shown measuring appliance be one not with the two-dimensional measurement device of orientation detection, it contains one and for example is the radiation source 270 of laser diode, lens 272, two-dimensional grating 274, a pair of detector 276 and 278, housings 280, some external line 282 and electronic circuits 284.The same with Figure 10 embodiment, laser diode 270 and detector 276,278 are preferably on the same optical flat.Figure 11 B illustrates the detector 276,278 of looking from XIB-XIB and the planimetric map of light source 270.Detector 276 is as the X-axis detector, and 278 as the Y-axis detector.Grating 274 is focused on the X detector 276 at the first-order diffraction light on the directions X, then is focused on the Y detector 278 at the first-order diffraction light on the Y direction.
Utilize the preferred embodiment of the present invention ratio of equivalent pinhole to be easier to aim at, and if be made into an integrated optics unit, looser tolerance requirement then had.Special when the local oscillations field be that non-zero order diffraction light by grating is when producing, owing to the position of pin hole is relevant with wavelength, so above-mentioned situation is particularly important.Like this, the wavelength stability of lighting source requires when using equivalent pinhole when using physical pin much loose.
In preferred embodiments more of the present invention, utilized other to determine the method for direction of motion.In these preferred embodiments, utilize the mechanical motion of an optical element to determine direction of motion.Two detectors are provided in preferred embodiments more of the present invention, and the optical illumination that will make optical grating reflection or diffraction along moving of a direction is to one of them detector.Figure 12 A-12B and Figure 13 A-13B show two preferred embodiment of the present invention utilizing this principle travel direction to survey.
Figure 12 A and 12B illustrate the principle of one of them preferred embodiment.Wherein to comprise one be the radiation source 292 of partial coherence, lens 294, detector 296, second detector 298 and an a pair of grating 300,302 for laser diode for example to measuring appliance 290 at least.Grating 300 and 302 is installed on the bistable state wedge element 304.When detector is on the position shown in Figure 12 A element 304, make the light directive detector 296 that grating 300 reflected or reflected when a direction is moved.When measuring appliance moved in opposite directions, the friction force between element 304 and the tested moving surface made element 304 forward the position shown in Figure 12 B to.At this moment the radiation that grating 302 reflected or reflected is with directive detector 298.So just, can be according to being which detector has produced signal and determines travel direction.
This embodiment is extended to two-dimentional work can be reached like this: replace element 304 with the four surperficial pyramid elements of working in a similar manner; Replace 2 detectors with 4 detectors; Replace one-dimensional grating with two-dimensional grating.
Figure 13 A and 13B illustrate the embodiment of the second kind of operating direction detection method that has utilized two adjacent gratings.The same with Figure 12 A and 12B, this embodiment also comprise one for example for laser diode be radiation source 292, lens 294, the detector 296 and 298 of partial coherence at least.This embodiment also contains two gratings 310 and 312.These two gratings 310 and 312 respectively have two parts that grating frequency is different, and for example left-half is 150 lines per millimeters, and right half part is 170 lines per millimeters.The position below that grating because of and friction between surperficial 42 move, up to a predetermined block of running on the direction of motion.The design of two and half parts of two gratings makes, one of them half part will be covered (i.e. the anti-zone of a grating covered another grating open area) after the motion, and their other half part is (metal that is them partly overlaps each other) of printing opacity, though generally dutycycle at this moment no longer is 50%.The below grating will make the effect of its two halves exchange along the motion result of another direction, thereby make under two direction of motion different reflection angle is arranged, and then the different detector that throws light on.These two kinds of situations are shown in Figure 13 A and 13B respectively.Travel direction can be according to being which detector has produced signal and judges.
Figure 13 C and 13D illustrate the another kind of system that converts another grating from a grating to.Only show grating self among these figure.Upper part is not made up of with respect to the reflecting element 400 of detector motion some.Lower part is made up of the grating region of alternately arranging with different cycles 401 and 402.On position shown in Figure 13 C, element 400 has blocked grating region 401, makes the light that incides on the grating be directed to an angle direction that cycle determined by grating region 402 (incident optical energy " is seen " these zones and partly seen through).When lower part moved on second position because of the friction with kilsyth basalt face to be measured, element 400 exposed shading light gate region 402 in zone 401, thereby incident light is directed to an angle direction that cycle determined by grating 401.So identical with the situation among Figure 13 A and the 13B, can switch the detector that can receive light.
By based on identical principle shown in Figure 13 A and the 13B, replace original gratings with two two-dimensional gratings that are divided into 4 zones, just can become the principle popularizing of this embodiment of the invention two-dimentional.
Figure 14 illustrates another principle based on the embodiment of the superficial velocity measuring system of Doppler shift.Different with above-mentioned measuring appliance, this measuring appliance need not use grating.One is optical element 322 of light source 320 collimated back lightings of partial coherence at least, and this element contains first plane 324 and second plane 325 that is parallel to surface 42 that an angle is also arranged with it near surface 42.The light of (preferably plate with the reflection horizon on this plane) reflection is focused on the detector 328 by lens 326 from plane 324, as the local oscillations field.A part of light by surface 42 reflections also is focused on the detector 328, interferes with the local oscillations field.Because the translation on surface, there is Doppler frequency-shift on surface 42 to the light of detector 328 reflections.So contain an oscillationg component that characterizes the translation on surface 42 in the detector signal.Should be noted that plane 325 do not work in detection process.Be also pointed out that in addition all optical elements all can be installed on the optical element 322, form the measuring appliance of an integrated form.Utilize two clinoplanes and two detectors to can be generalized to two-dimensional measurement.
According to preferred embodiments more of the present invention, the reverberator of reflection local oscillations field keeps clear of the surface in tested speed.Figure 15 and 16 shows two preferred embodiment of the present invention that embody similar principles.
Measuring appliance shown in Figure 15 contain one for example for laser instrument be light source 350 and an optical element 352 of partial coherence at least, the latter is contained all surfaces 356 of reflection of the surface 354 of a partial reflection and part transmission and.This measurement preferably also contains: lens 358 that make light source 350 collimations; A spatial filter, it is realized by the lens 360 that light is focused on the detector 362 in the present embodiment; And signal processing circuit 364.As previously mentioned, focused light plays a part equivalent pinhole.Light source provide be directed to the surface 42 be the radiation of partial coherence at least.
Light from light source is resolved into two-beam by surface 354, and to surface 356 reflections, another restraints 354 directive surfaces 42, light transmission surface to a branch of light by surface 354.See through surperficial 354 directive detectors 362 once more from the light of surface 42 reflections.All reflected on 356 on the surface from the light of surface 354 reflections, make also to be directed to detector 362 after the reflection for the third time of this Shu Guang through surface 354.The light of in element 352, propagating because of reflection repeatedly (local oscillations light) with by surface 42 in the optical path difference between the light that detector reflects should the scope at the coherence length of laser.As foregoing embodiment, the translation on surface will cause a detector signal that can characterize the alternation of translational movement.In other preferred embodiments of the present invention, the surface 354 can be a grating, and the local oscillations field goes out from certain first-order diffraction photoconduction of this grating.Do not need an angle is arranged for this situation surface 354 with surface 42.
Though surface 356 is reflected fully, it also can be the part transmission or partially absorb.This will reduce the local oscillations field.If the surface 356 is part transmissions, then the light of transmission can be used for the intensity of measurement light source by another detector, thereby intensity modulated that can the compensatory light amplitude is illustrated in conjunction with Fig. 3 A and 3B as the front to improve the performance of velocity range lower end.
According to a preferred embodiment of the present invention, in surface 354 and the space of surface between 42 filling second kind of optical medium, with the flatness of improving surface 42 (if it is non-rigid, for example paper) with prevent the dust aggregation.
According to another preferred embodiment of the present invention shown in Figure 16, measuring appliance is made with the cube splitter of a remodeling.One best collimated from being the surface 382 that the light of the light source 380 of partial coherence is directed to a partial reflection, part transmission at least for laser instrument for example.The light that sees through surface 382 is directed to surface 42, passes through from a part of light of surface 42 reflections after the reflection on surface 382 through focusing system 386 directive detectors 384 again.Be directed to a reverberator 388 from the light of surface 382 reflections, its reflected light sees through surface 382 back directive detectors 384.Like this, the effect of this beam splitter is exactly an interferometer, makes surface 42 will produce Doppler frequency-shift in tangential direction (being parallel to the surface) between the reflected light (as local oscillations light) of reverberator 388 and surperficial 42 the reflected light with respect to the translation of device.
Like this, will interfere at detector 384 from surface 42 with from the light of reverberator 388 reflection.The size design of this optical element makes the optical path difference of this two-beam in the coherent length scope of light source 380.
This layout makes the partial reflection surface, and all reflecting surfaces and measured surface are not parallel mutually.So will contain a caused oscillationg component of the Doppler frequency-shift because of surface reflection in the detector signal, this composition can characterize surface translation with respect to device on its tangential direction.
Preferably collimated from the light that light source 380 sends.The light that arrives detector 384 preferably is focused in its surface, makes it go up the some picture of formation light source 380.The partial reflection surface or the whole reflecting surface that utilize two quadratures to tilt can obtain the two-dimension translational measurement.
The relative velocity that is proportional between the measuring appliance and surperficial 42 from the Doppler frequency-shift of light of surface 42 reflections is inciding lip-deep light beam and can be mapped to component on the angular bisector direction between the surface reflection light beam on the detector.Doppler shift and optical wavelength are inversely proportional to.The selection of optical medium preferably can make dispersion of refractive index can allow the angle between angular bisector and the surface plane that some changes take place, and this change can compensate the influence of wavelength shift to Doppler frequency-shift.Can obviously reduce the measuring error that limited spectral bandwidth and wave length shift caused like this because of light source.
Method shown in Figure 15 and 16 and embodiment provide the translation of measuring the rough surface of motion tangentially more inexpensive, anti-interference arranged, need not aim at and accurate equipment.The same with the explanation that other embodiments of the invention are done, this method has a wide range of applications in the various application that utilize translation measurement.
Figure 17 illustrates another preferred embodiment of the present invention.This embodiment provides enhancing to a specific polarization to the light by surface reflection.A kind of method by providing different polarizations to determine direction of motion to surface reflection and local oscillations light once had been provided Fig. 3 C, by placing a birefringent plate in surface and the light path from the light on surface phase shift is provided passing.But this method is based on following supposition.When light from the teeth outwards reflex time will keep its polarization state.But in fact usually be not like this, thus the expection meeting will go bad by the orthogonal signal that detector produces, this in addition can make the change of same direction of motion generation sign.
Add that between birefringent plate (" quarter-wave plate ") and surface a linear polarizer can make measurement insensitive to the character on surface.This polarizer is given the linear polarization that has added it from the light intensity of surface reflection, no matter and the character on surface how.The axle of polarizer place with the axis 45 of birefringent plate, reflected light will be transformed into circularly polarized light by birefringent plate, the directive detector through behind the polarizer.So,, on the detector of two cross polarizations, also still can guarantee to obtain accurate orthogonal signal even itself do not protect polarization characteristic when the surface.
Another characteristic of this layout is to be placed on grating " on the top " (being placed between grating and the surface to substitute) to birefringent plate.Local oscillations light will be subjected to twice phase shift (for quarter-wave plate, generally speaking will obtain the optical path delay of half wavelength), and surface reflection only is subjected to a phase shift, thereby guarantee orthogonal measuring.
First preferred embodiment of motion detector 500 shown in Figure 17 has comprised this feature especially.Motion detector 500 comprises the partial coherence light source 502 of the collimation lens 504 that preferably thrown light on.(being that each bar light is all parallel) that the light that penetrates from lens 504 belows preferably collimates.A quarter-wave plate 506 is arranged below the lens, and it has a grating 508 down again.Owing to passed through wave plate twice from the light of optical grating reflection/diffraction, so between its two quadrature components one 180 ° phase shift is arranged, though wave plate 506 and grating 508 among the figure (are two discrete elements, but they can be combined into an element, for example can be in deposit or mold pressing on the wave plate surface grating.
Preferably also has a linear polarizer below the grating.The light that reflects from the surface (not going out) of polarizer below will be circularly polarized in the second time behind the process wave plate like this.Here, because light will pass through polarizer 510 for the second time before arriving wave plate 506, so polarization has obtained strengthening and avoided " pollution " to measurement.
All incide on the detector module 512 from the light of optical grating diffraction and from the light of surface diffuse reflectance with an angle of time determining by grid stroke distance and the order of diffraction.Detector module 512 contains a phase grating 514, and the latter is resolved into two parts that preferably equate to incident light, and this two parts light is being aimed on the detector 520 and 522 through being mapped to one behind a pair of polarizer 516 and 518 respectively.Polarizer 516 and 518 axle are preferably regulated to such an extent that the optical grating diffraction light of same intensity can be provided to two detectors mutually at an angle of 90.Respective element among the function of detector module 512 and Fig. 3 C identical.That is to say that detector module is resolving into two linear polarization compositions from the circularly polarized light of surface reflection, and each linear polarization composition will be respectively interferes with the part of the light of 508 diffraction of grating.Diffraction light is an axle linearly polarized light at angle at 45 all with two polarizers, and it also preferably is divided into equicohesive two-beam by grating and is detected device surveys.Carry out zero crossings counting by two signals that detector is detected, can determine the amount of moving easily, then can determine travel direction according to the relative phase of these two signals according to Doppler shift.
In a preferred embodiment of the invention, module 512 and light source 502 and an electronic module 526 are installed in a base plate or the heat radiation substrate 524 together.Electronic module 526 can contain one and be used for controlling the controller of light source 502 and being used for from the circuit of detector 520,522 received signals.Electronic module 526 preferably can partially or even wholly carry out aforesaid signal Processing, so that the information about the size and Orientation of apparent motion to be provided to computing machine or other device (not shown).
Figure 18 illustrates another kind of motion detector 530, and its structure is similar with Figure 17 device substantially.Yet this motion detector has some noticeable characteristics.In order to be easy to explanation, in the detector 530 with Figure 17 detector 500 in similar part represent with identical code name, these parts are not described further.
In Figure 18, local oscillations light spatially is to separate with the illumination light on surface and the light path of diffraction light.In addition, in Figure 18, be advantageously provided a breach (cut-out) 532, be used for making from the light of optical grating diffraction identical with optical path length from the light of surface reflection to be measured.Illustrated once that these two interferences of light should occur on the detector as far as possible.Because the light path of surface reflection is greater than the light path of optical grating diffraction light, this will have high requirement to the coherence of light source 502.In a preferred embodiment of the invention, breach 532 can make the light path of surface reflection reduce, thereby has mated two light paths.
The local oscillations light layout of separating as shown in Figure 18 because of have only a transmitted light beam not to the illumination of the diffraction light of projection surface from but doppler mode work is desirable, so this layout has advantage in essence.But, the light beam separated into two parts, a part is used for producing local oscillations light, and another part is used for throwing light on, feasible quality to light beam has higher requirements, and its interference free performance will be worse than the scheme that most of or whole illumination light is used to produce simultaneously local oscillations light and surface illumination.
Though above-mentioned breach also can be used for for example other preferred embodiments of the present invention such as Figure 17 embodiment, for the situation that coating shielded, preferably anti-zoned trace or base plate 534 are provided at the neighbouring surface place, this breach is with particularly useful.This base plate can increase the light path of surface reflection, but can not change the light path of optical grating diffraction light.Provide protective seam also to be applicable to above-mentioned many embodiment.In addition, for reduce laser beam by the time the parasitic light effect, other parts in base plate 254 or the light path can also painted (promptly carrying out spectral filtering).
In the embodiment shown in Figure 18, the structure that produces reflected light and diffraction light is with shown in Figure 17 different.In Figure 18, be one 1/8th wavelength sheet 538 below the phase grating 536, a reverberator 540 is arranged below it again.This reverberator 540 preferably directly is produced on the wave plate 538.Owing to passed through 1/8th wave plates for twice from the light of reverberator reflection, so reflected light is circularly polarized.Preferably successively pass through linear polarizer 542 twice from the light of surface reflection.So linearly polarized light that this only strengthens.This system working condition in other respects is identical with Figure 17's.
In other preferred embodiments of the present invention, may be placed on a quarter-wave plate in the light path of light source 502 light emitted bundles, make light be transformed into circularly polarized light.So it can wherein no longer need a plurality of layers than much smaller (so cost is also lower) shown in Figure 17 and 18.In addition, used in the embodiment of the invention of wave plate, also can adopt the wave plate that can generate elliptically polarized light (rather than above-mentioned circularly polarized light) for those.
In preferred embodiments more of the present invention, can on the emitting surface of laser diode (it self produces linearly polarized light), deposit the quarter-wave lamella that one deck is made up of birefringent materials such as for example quartz, to produce circularly polarized light.This deposition procedures is preferably made the part of the operation of diode, for example at the top of the outside of vertical cavity surface-emitting laser diode distributed Bragg reflector deposition of birefringent layer.Because coating area at this moment is the area of the surface of emission, so this scheme can only be used the much less birefringent material.And little birefringent layers can be made more accurately than big birefringent layers.Add a linear polarizer and can constitute an optical isolator assembly below birefringent layers, being used for decaying turns back to parasitic light in the laserresonator.
Similarly, in preferred embodiments more of the present invention, need polarizer separately so long as not indicating as more aforementioned embodiment of the invention, then linear polarizer is produced on the detector surface.Utilize such polarization detector can reduce to assemble the complexity of motion detector.Can be used in the detector top applies the polymkeric substance polarizer and makes this detector.The dielectric layer making polarizer that perhaps, also can have fine rule groove (live width is a wavelength magnitude) by deposit on detector face.
Figure 19 A and 19B illustrate two kinds based on the integrated form motion detector that is similar to the orientation detection principle shown in Fig. 3 C, 17,18.
Figure 19 A shows a motion detector 550 of constructing on an optical unit 552, and it comprises a beam-splitting surface 554 and two lens 556,558.In connection with lens 556 laser diode light source 560 has been installed, these lens make the optical alignment of light emitted.Collimated light beam 561 is mapped on the beam-splitting surface 554, and the latter is resolved into first 562 and second portion 564 to light beam, and wherein light beam 562 continues to propagate on the surface 12, and 564 of light beams are reflected on one of all directions wave plate 566 and the minute surface 568.Light beam 564 becomes circularly polarized light at twice through after the wave plate, returns to beam-splitting surface 554.
The end face and the bottom surface that are noted that motion detector 550 are uneven, so the folded light beam on surface 12 has Doppler shift with respect to incident beam.This Doppler shift (itself and sign) is surveyed motion.In addition, in preferred embodiments more of the present invention, each lens have been plated the influence of reflection horizon to avoid repeatedly reflecting that disappear.
Second kind of integrated form motion detector 590 shown in Figure 19 B also embodied similar principle.All optical elements of this system all are installed on the optical unit 592, have wherein also pressed from both sides a grating 594, and grating, end face and bottom surface are preferably parallel to each other.Function class is similar to that two lens 596,598 of lens 556,558 preferably are produced in the optical unit 592 among Figure 19 A.In Figure 19 B, there is the element of similar functions to represent with similar code name with corresponding element among Figure 19 A.A reference beam is reflected by grating 594, and one of all directions that back side of directive is minute surface wave plate (556,568) passes through reflections affect lens 598 for the second time thereafter.The light beam that sees through grating preferably through a linear polarizer and optional protective seam directive surface 12 again, is reflected on the lens 598 then.The working method of this detection system and aforesaid similar.
Figure 19 C and 19D illustrate the details of detector module 610, and this module is used to utilize the system of wave plate influence by grating and/or surperficial institute beam reflected.The example of this system have Figure 17,18 and 19A in motion detector.In these motion detectors, when light source light was linearly polarized light, wave plate can shift near detector.In this case, the wave plate size can be little when being placed on other positions, and can integrate with detector as the front to the explanation of polarizer in preferred embodiments more of the present invention.
For these embodiment, the placement of polarizer should make to have only directive and just pass through its (for example placing near surface to be measured) from the light on surface.The polarization axle of polarizer place with angle at 45, the polarization direction of light source light, thereby make polarisation of light direction and local oscillations polarisation of light direction angle at 45 from the surface.
In this case, the detector module shown in Figure 19 C and the 19D 610 can advantageously replace module 512 among Figure 17,18 and the same detection principle of utilization among Figure 19 A but module 576 that form changes.In Figure 19 C and 19D, there is the element of identical function to represent with identical code name with respective element among Figure 17,18.
Except the front in polarizer 516 and 518 was provided with a quarter-wave plate 612, module 610 and 512 was similar.Quarter-wave plate, polarizer and polarization of incident light orientation is shown in Figure 19 D, and this figure is the sectional view along the D-D line of Figure 19 C of looking from the below.The polarizer axle is by code name 614,616 expressions among the figure, and the polarization axle of quarter-wave plate is by code name 618 expressions.The polarization direction linearly polarized light consistent with an axle of wave plate can not change its polarization state through behind the wave plate.The polarization direction will be transformed into circularly polarized light with the linearly polarized light at axle 168 angles at 45 through behind the quarter-wave plate.
The polarization direction of code name 620,626 expression grating incident waves and surface echo, which ripple is that direction 620, which ripple are that direction 626 is that it doesn't matter here.And one of them wave polarization direction can be 626, rather than 626.
At work, the polarization direction of incident wave is 620, and it is transformed into circularly polarized wave.This circularly polarized wave is polarized device 516 and decomposes two identical compositions with 578, and making has two to wait the linearly polarized wave of amplitude to incide on detector 520 and 522.But differ 90 ° (polarization direction quadratures simultaneously) time phase of these two ripples.The polarization direction is that 626 or 626 ' ripple its direction through quarter-wave plate the time is constant.Its also be decomposed ripple of two direction of vibration quadratures.But these two ripples have identical time phase.So each detector all will detect the interference of light wave.Provide two signals that differ 90 ° time phase.This phase differential can be used for determining direction then, as surveying in the situation at the standard quadrature.
If without wave plate 612; Then can stop surface reflection or local oscillations light selectively according to the polarization direction of local oscillations light and surface reflection with a detector polarizer.For example, if the polarization direction of light source light is 620.Then its can be that 616 polarizer blocks by axle.Like this, detector will only detect surface reflection, corresponding to Er
2Composition.Perhaps, if the polarization direction of surface reflection is 620, then axle is that 616 detector will only detect the local oscillations field, can compensate Eo thus
2Composition.
Be used for Eo
2The detector output of composition compensation can be used as a reference voltage, and its output voltage from another detector of being used for translation measurement is deducted.This has just formed a kind of " difference " detection mode.This for example subtracting each other can carry out on the trsanscondutance amplifier level, to eliminate most of DC voltage of detectable signal.Perhaps, also can adopt the Hi-pass filter that utilizes as shown in Figure 9 to remove the scheme of DC voltage.The bandwidth of compensating signal preferably limits according to the bandwidth of source noise.Otherwise in fact can add " irrelevant " noise (for example thermonoise) because of subtracting each other unnecessarily of compensating signal.
When light source is repeatedly cut off and is connected (for example when working in " sleep pattern " man-hour) for conserve energy or eye-safe, Eo
2The composition compensation then can reduce or exempt this complicacy without high-pass filtering, perhaps, if when light source cuts off, the capacitor in the Hi-pass filter is kept apart (making electric capacity can keep its electric charge to connect once more thus), even then do not have Eo up to light source
2Also lapping switch repeatedly of compensation is arranged.
Eo
2Another purposes of compensating measure is as the feedback in the source current control loop.Having very cataclysm (for example because big operating temperature range) if estimate light source power, is crucial for this control loop of the luminous power of controlling light source then.
When Vcsel (VCSEL) was used as light source, Figure 19 C and the 19D layout with wave plate 612 may not be useful.If operation is correct, some VCSEL can be operated on the direction in two possible orthogonal polarization orientation, at this moment on the some therein directions of light polarization on any preset time of the point.So the uncertain problem in polarization direction occurred.Because for given direction of motion, it is poor that two kinds of polarization directions can make the polarization detector of two quadratures provide opposite phases, so use VCSEL to go wrong in the system that the need travel direction is surveyed.
According to the layout shown in Figure 19 D, the polarization direction of supposing light source is 620 or perpendicular to 620 (illustrating).Then under the situation that does not have wave plate 612, for example polarizer 614 will or block or see through local oscillations light.So according to different light source polarization directions, the output of detector 522 is incited somebody to action or is high, or low, the output of this detector may be used to the conversion flag of a definite zero crossings count value sign (for example as) between control signal relative phase and the direction of motion.
Except being used to survey the detector of motion, only need to use such polarization detector (high or low) just much of that according to polarization direction output.But, if use two detectors (522 and 520), no matter then be that always the output of detector is arranged is high in which polarization direction, and another detector can be used for the compensation of Er2 composition with the surface measurements reflected light
In such scheme, the detector that other adds is had the polarization direction uncertain problem that solves VCSEL.Perhaps, also can allow VCSEL rotate a little with respect to its " the best " polarization direction." the best " direction of supposing the VCSEL polarization is α, thereby the advantage polarization direction is α or α+pi/2, and then the ratio R p of the diameter voltage of two detectors is:
Another polarization of one polarization
So for the best VCSEL orientation (for example along 626 directions) of α+π/4, no matter then the polarization direction of VCSEL how, for example the direct current composition that detected of two cross polarization detectors among Figure 19 D all will be identical.
Yet, if α+π/4+ β (arc), when the output of VCSEL would be on a polarization direction
, in the time of on another polarization direction
。So Rp＞1 when VCSEL is luminous with a polarization direction, Rp＜1 when luminous with another polarization direction.So, if VCSEL with respect to " the best " orientation rotation, the comparative result that is used between two detector DC voltage of translation measurement just can indicate the direction of polarization, and no longer needs extra special-purpose detector.
Overcome probabilistic another method of the possible polarization of local oscillations light and be and use a linear polarizer in the light path between light source and grating, and make either direction angle at 45 in its polarization axle and two orthogonal polarization orientation.So, when the polarization direction of VCSEL is 626 or 626, the time, the polarizer axle for example will be 620 directions.Perhaps, when the polarization direction of VCSEL was 614 or 616, the polarizer axle was 620 directions.To force the polarization direction of light source light identical with the direction of polarizer axle like this, its cost is to have lost the luminous power of half approximately.
Being superimposed upon low frequency parasitic noise on the higher frequency signals (for example Er2 and Eo2 composition and power circuit disturb) may influence the quadrature of high-frequency signal is surveyed, and its reason is as follows:
Lose the zero crossings incident of high-frequency signal.
Zero crossings incident genetic sequence changes, so the orientation detection of quadrature detector changes.
Counted the zero crossings incident of low-frequency noise, and this is accumulated in the measurement has gone.
According to various preferred embodiments of the present invention, can overcome possible low frequency modulations (replenishing or substituting) with signal processing technology as what aforementioned lights learned a skill, these methods can be used separately, but also combination:
Suppose P and Q be for example for the detector among Figure 19 C to 520 and 522 output signal.Ideally except have along with the difference of direction of motion+time phase difference of 90 ° or-90 ° and additional noise, P and Q be complete with.Supposing has derived signal D=P-Q and S=P+Q from signal P and Q again.So got rid of noise among the signal D from P and the common noise source of Q.90 ° time phase difference is arranged between D and the S in addition.Therefore, D and S and P and Q equivalence when not having noise.If but common noise source is stronger, then the zero crossings of the D zero crossings of accurately having measured translational movement S then can be used to help determine travel direction.Also have, the elimination of common noise is not limited to low frequency.
Amplifying signal can be divided into two (or a plurality of) frequency ranges.Can select suitable passage according to the frequency of measuring.
Utilize one by signal frequency control and can be adaptive to the adaptive bandpass filter of the frequency change that may accelerated motion with respect to the OTM device be caused on the surface.Adaptive bandpass filter can also reduce other noise source, for example thermonoise and 1/F noise etc.It can be realized by using the voltage controlled capacitor in high pass and the low pass parts.
Employing makes the high-frequency signal amplitude that obtains greater than the low frequency signal amplitude to the higher magnification of high-frequency signal.So the zero crossings of high frequency counting only can be subjected to less influence.
Figure 27 illustrates a preferred embodiment 899 of the self-adaptation band-pass circuit that suppresses the low-frequency noise in the high-frequency signal.A zero crossings detector 900 becomes the analog signal conversion of input end the logical signal at output terminal 920 places.When signal is low frequency (for example 50Hz), transistor 931 and 932 not conductings in the most of the time, at this moment electric capacity 940 with long time constant (0.1S) charging, is suitable for surveying low frequency signal by resistance 945.On the other hand, when zero crossings frequency height (surpass hundreds of hertz), will there be high pass circuit 950 drive currents to flow through the base stage of transistor 931 and 932, so circuit 940 will be by resistance 960 to reach the time constant charging of 0.1ms for a short time.Like this, the threshold value at operational amplifier 970 positive input terminal places will be followed low-frequency noise and be changed, thereby suppress the detection to it, make the output of operational amplifier depend on high-frequency signal.Electric capacity 980 is used for suppressing the spontaneous oscillation of operational amplifier 970.Should be noted that, Figure 27 has just provided this exemplary embodiments on the one hand of the present invention, self-adaptation zero crossings detector can have many kinds of implementation methods, and can use other element (for example field effect transistor, different resistance value and capacitance and different operational amplifiers).
Orthogonal motion is measured by means of measuring two same signals that the constant phase shift amount is arranged therebetween.The motion size is measured by the zero crossings number in the given interval.Direction of motion is come definite by the symbol (i.e. " height " or " low ") of signal in another passage of zero crossings symbol (i.e. " low to high " or " high to low ") that compares on the passage.
The zero crossings counting that noise possibility on the orthogonal signal is extra.If zero crossings has not taken place twice a signal in another signal has time of reindexing, then their direction is opposite, is zero after the addition.Yet if the zero crossings of a signal has taken place to move in time, the order that zero crossings takes place in two passages may turn around, and the result causes two orientation detection errors in the passage, the clean counting error of neither one after the addition.
According to preferred embodiments more of the present invention, utilize " the minority is subordinate to the majority " in certain time interval can proofread and correct because of the zero crossings incident and fall the error that is caused.Suppose that (or " direction of motion is constant in unit ") time in each time interval.This means with resolving power and exchange accuracy for.Carrying out the zero crossings counting in each unit in succession is easily.Each unit all begins in last unit end, and finishes when predetermined number or more zero crossings incident have all taken place in the passage of two quadratures.Determine the direction of this whole unit then according to most of directions of being judged in the unit (by two passages or only by one of them passage judgement), preferably no matter the actual count in two passages why, a fixing count number (so resolution characteristic is by one times of decline of the least count number in this unit) is all represented in each unit.Easily, can be 3 or 4 unit with scale.Requiring two passages all to count down to the least count number that equals or exceeds a unit is in order to prevent that the high frequency noise in the passage from having become " majority ".
In the optical translation measurement of according to some preferred embodiments of the invention above-mentioned many types, can before further amplifying AC signal, remove easily with a Hi-pass filter in the first amplifier stage output by the detector DC voltage that the local oscillations energy forms.Therefore, the cutoff frequency of high-pass filtering has determined minimum measured speed.
When optical translation measurement was used as an input media (for example Genius mouse or other pointing devices), low speed limit may be an important parameter for the user.For example when the user move lentamente or during near the ad-hoc location on the screen low speed limit be important.
For make the user lentamente moving cursor make it on screen location accurately, may use gradual (not being a sharp change) Hi-pass filter, use the wave filter that reduces to amplify slope gradually with frequency will near its cutoff frequency the time, lose zero crossings.This will approach to reduce tested speed in limited time effectively by filter configuration following in speed.Cursor speed will be reduced to zero and OTM still is in and measures (and still in motion) in the bandwidth gradually like this.This " deceleration " mechanism also can be applicable to software or survey as zero crossings after the part of signal analysis, for example by measurement count frequency (being speed) and approach to reduce under the wave filter speed of cursor in limited time at count frequency.Cutoff frequency is lower than the motion of about 0.5mm/s corresponding to speed in a preferred embodiment of the invention.In a preferred embodiment of the invention, Hi-pass filter at the slope that is lower than the cutoff frequency place less than every approximately frequency multiplication 20db.
Figure 23 illustrates the desirable curve 750 of cursor speed as the device function of speed.This figure also illustrates this kind curve 752 in accordance with a preferred embodiment of the present invention.If also shown is when using a sharper Hi-pass filter with the curve 754 that obtains.Be appreciated that curve 754 makes the system in fact can not the low speed moving cursor.On the other hand, because essential zero-frequency and the low frequency composition got rid of, ideal curve can not be accomplished.Yet the curve 752 of transition gradually but allows cursor accurately to locate with the form of nonlinear transfer function.In an exemplary device, curve 742 can be at a certain velocity amplitude, 1mm/s for example, on be linear, and be lower than in the speed of hand (device) and will no longer cursor moved 1/3rd to two of minimal linear velocity amplitude/a period of time.Certainly, also can adopt the milder curve of another transition.
As previously mentioned, the precision of optical translation measurement depends on the number of grating lines in the illuminating bundle.So for the higher curvature surface, may be inadequately with the optical devices precision of planar shaped.An example of this application is the rotation of the axle 600 of measurement shown in Figure 20 A and the 20B, and the radius of axle wherein may be less.Rotate measurement for axle and can place (being placed on its side) along axle by handle assembly.For the curvature that adapts to axle and the axle of energy measurement minor radius, can be with the leading section of a special optical element 602 as device.Schematically illustrated Figure 20 A of the shape of this optical element and B.The diameter of this element mates with the diameter of axle, and an one-dimensional grating 604 is arranged on the surface of this element, and its lines are parallel to the axis of axle.The light of light source 606 is focused on the center of axle, so be constant on its phase grating.This measurement preferably belongs to the zero level type.Detector 608 is surveyed from the axle surface reflection with from the light of optical grating reflection.Notice, be clearly shown that light source and detector preferably position but depart from axially having mutually on the circumferential position with respect to axle as Figure 20 B.
The front end optical element can change different shaft diameters, and reaches high-acruracy survey by the major part that can " see " the axle periphery.Orientation detection can be realized with following several method: utilize asymmetric grating, utilize another part of focusing on the lip-deep light of axle and with aforesaid cross polarization method detection direction, perhaps other method (for example investigating the polarity of motor drive current).An advantage that adopts Figure 19 A and 29B layout is the equivalent optical path that can make them in the same part generation local oscillations light of light beam and scattered light.
The motion that is parallel to rough surface may import not Z axle (up and down) motion of interest.The Doppler shift of Z axle athletic meeting causing surface reflection, and in general the phase place of light also will change with the synthetic of Z and X or Y speed.A kind of method that their Relative Contribution is separated is, for X-axis and Y-axis all measure simultaneously+1 and-1 grade diffraction light (perhaps other order of symmetry, for example ± 2, ± 3 etc.).Impinge perpendicularly on geometric layout on the measured surface for light wave, if the speed of X, Y direction is Vx and Vz, optical source wavelength is λ, and grid stroke is apart from be ∧, then X and Z motion synthesize the Doppler shift that is produced right+1 order diffraction is:
ω
÷＝(2π/λ)(v
xsin(φ)-v
z(1+cos(φ)))，sin(φ)＝λ/Λ.
The Doppler shift of right-1 order diffraction is:
ω
-＝(2π/λ)(-v
xsin(φ)-v
z(1÷cos(φ))).
The signal that has the difference of two frequencies as can be seen has:
ω+-ω=(v of 4 π/Λ)
x, and ω is arranged with the frequency signal
++ ω
-=(the v of 4 π/λ)
z(1+cos (φ))..
Get two inferior orthogonal signal of these two levels and will obtain following signal:
A
+＝cos(ω÷t÷Ф
+)，B
+＝sin(ω
+t+Ф
+)，A-＝cos(ω_t+Ф_)，B
-＝sin(ω_t+Ф_).
Utilize the sum rule of sine and cosine functions, can form two groups with frequently and the signal of difference frequency generation, and two signals maintenance orthogonality relations in every group:
C-＝B
+A
--A
+B
-＝sin(ω
+t-ω_t+Ф
+-Ф_)，
D-＝A
+A
-+B
+B
-＝cos(ω
+t-ω_t+Ф
+-Ф_)，
C
+＝B
+A
-+A
+B
-＝sin(ω
+t+ω_t+Ф
++Ф_)，
D
+＝A
+A
--B
+B-＝cos(ω
+t+ω_t+Ф
++Ф_).
So signal C-that obtains and D-branch have been opened corresponding contribution, and the Z axle parasitism of having removed in the measurement of E axle is contributed.In addition, "+" composition can be used for only measuring the Z axle specially, and the measurement of for example obstructed zero crossings order diffraction comes the detecting touch formula to give directions touch or " kowtow and hit " of device.
When Z axle speed was higher, X or Y measured and generally also can be used for to the Z axle translation and make guestimate." kowtow and hit " " on/down " characteristic of operation like this with regard to detectable finger.In addition, " kowtow and hit " operation is surveyed in the unexpected deceleration and the acceleration suddenly that also might utilize finger to take place respectively when touching and unclamping the contact.For this situation, only need to use the absolute value (or its derivative) of Z axle speed.
Figure 21 illustrates the another kind of method of determining the translation of Z axle and accurately determining transverse movement, there is shown the part of a system 700, and wherein two detectors are right, and Z detector 702 and X detector 704 are used for determining the motion of Z and directions X.In preferred embodiments more of the present invention, each free pair of orthogonal polarization detector of Z detector and X detector is formed, and for example the detector shown in Figure 19 C and the 19D is right, and for example the element 576 among the element among Figure 18 512 and Figure 19 A, the 19B.The surface has the speed (speed of relative detection system) of X and Z direction simultaneously.Speed total among Figure 21 is represented (Vz is in normal direction, and Vx is in parallel direction) with vector V.
The position of Z detector 702 preferably makes its receive only to contain and result from the Doppler shift energy from surface 12 (supposition from the light of unshowned light source impinge perpendicularly on the grating) here of Doppler shift of Z motion.The X position of detector makes it can receive for example the first-order diffraction light and the surface reflection Doppler shift light that becomes the φ angle with surperficial 12 normal of grating.The catoptrical frequency displacement of Doppler that the X detector is detected is the surface with respect to detector along the move combination of the Doppler shift that produces of X and Z direction.
If Ux is along the speed component of the angular bisector direction between zero order light and the one-level light.Then:
U
x＝V
xsin(φ/2)+U
zcos(φ/2).
The Doppler shift that X and Z detector record is respectively:
F
x＝2U
xcos(φ/2)/λ，and
F
z＝2U
z/λ.
Just can be in conjunction with the above-mentioned relation formula according to measuring the X component Vx that Fx and Fz determine speed:
V
x＝λF
x/sin(φ)-λF
zctg(φ/2)/2.
If use first order optical grating diffraction light, sin (φ)=λ/∧ then, wherein ∧ is the grid stroke distance.So:
V
x＝Λ(F
x-F
zcos
2(φ/2)).
When φ hour,
Make the decoupling of Z simplified:
Vx＝∧(Fx-Fz)
In order to determine X and Y motion, need use three detectors shown in Figure 22 A, what this figure drew is the distribution of detector on the focal plane of system 700.
More accurate uncoupling is arranged if desired, can be with a zero level detector that separates.By making a part of illumination light deviation on φ/2 angles, will only measure the motion of Z axle by the new zero order light that deviation light produces, but at this moment Doppler shift to be multiplied by a coefficient 1+cos (φ)=2cos
2(φ/2), new in other words Doppler shift are with to be coupled to the Z axle motion that X, Y-axis go in measuring identical exactly, thereby can be with its decoupling accurately.
In another preferred embodiment of the present invention, also might only utilize the non-zero order reflected light to come effect uncoupling to the motion of X and Z axle.Because this method has been avoided near the detection the zero-frequency, so may be desirable.
Simple in order to illustrate, suppose: vertical illumination, use three detectors (i=1,2,3), grid stroke of each detectors is apart from Λ
i, and in X-Y plane with respect to X-axis with angle γ
iPlace.So detector is pressed all number N that following formula is measured a pseudo-sine signal
i
Wherein X and Y are respectively the translational movements along X-axis and Y-axis, and Z is the translational component along the plane normal method, and λ is an optical source wavelength, φ
iBe i detector angle with respect to the illumination light direction in the plane of reflection, φ
iWith Λ
iRelation be sin (φ
i)=λ/Λ
i
For example, if detector (γ on X-axis
1=0), another (γ on Y-axis
2=pi/2), the 3rd with other two 45 ° of (γ are arranged
3=π/4), then:
Can take off state approximate:
1+cosφ
1＝1+cosφ
2＝1+cosφ
3≡k
z.
In addition, if used simple two-dimensional grating (seeing Figure 22 B), then (suppose that also the φ angle is little) with square identity element:
Λ
1＝Λ
2≡Λ
Λ wherein
3Representative is inferior with the first order at X-axis angle at 45.In Figure 22 B, the 710th, one-level Y detector, the 712nd, one-level X detector, the 714th, one-level X+Y detector.
In conjunction with the following various expression formula that obtains X, Y, Z:
X＝Λ(N
3-N
2)
Y＝Λ(N
3-N
1)
Obviously, the translation of X and Y direction is by two two detector measurements on measured axis not.This has just got rid of the coupling of Z axle, and also can obtain much better resolution energy rate when direction of motion approaches perpendicular to a main shaft simultaneously.
Another example and last example are similar, and just Λ 3 doubles:
Λ
1＝Λ
2≡Λ
This situation is equivalent to a detector on X-axis, second on Y-axis, and the 3rd middle at them (seeing Figure 22 C) makes that three detector row are in alignment.In Figure 22 C, 714, representative (X+Y)/Z associating class survey device.This layout helps making (particularly to being used for the beam splitter with static phase shift detection direction).It also obtains with the two-dimensional phase grating of a precision easily.
Convert in this case along each translation and obtain:
X＝Λ(2N
3-N
2)
Y＝Λ(2N
3-N
1)
Another may layout be a detector (720) on X-axis, in addition two detectors (722 and 724) then relative it place symmetrically, also be γ
1=0, γ
2=γ, γ
3=-γ, and Λ
1≡ Λ
x, Λ
2=Λ
3≡ Λ
y(seeing Figure 22 D).
Suppose 1+cos φ once more
1=1+cos φ
2=1+cos φ
3≡ k
z:
(just not necessarily) makes following selection so that the resolution characteristic of X and Y is identical easily:
Therefore, if definition
Just can derive:
Here make the Z axle once more by decoupling, even and motion high resolution characteristic is also arranged near perpendicular to any one main shaft the time.
In addition, in the translation of extracting the Z axle, γ is set at tan (γ)=2 for convenience, so
Any detector layout can cooperate (this grating no longer is made up of the array of rectangle identity element in general) with a two-dimensional grating, perhaps also can use on two or three gratings that separate, they are preferably thrown light on, only one or two detector are contributed the local oscillations field everywhere by the different piece of original beam.
Should be noted that, though Figure 22 A, 22B and 22C time only show a detector to each order of diffraction, just in fact each detector all is made up of the pair of orthogonal polarization detector, and for example those polarization detectors shown in the element 576 among 512 among Figure 19 C and 19D or Figure 18 or Figure 19 A, the 19B are right.
The power that is used for the light source of apparatus of the present invention generally is little.But in preferred embodiments more of the present invention, still may be desirable to provide the mechanism of protection eyes, not take care to allow laser radiation to eyes of user to reduce.In a preferred embodiment of the invention, provide an additional detector, its position makes it receive only from the light of surface reflection and does not receive light by optical grating reflection or refraction simultaneously.Just can easily accomplish this point as long as this additional detector is placed between zero order diffracted light and first-order diffraction light or other order diffraction light.This detector also can be used for foregoing Er easily simultaneously
2The composition compensation.For example, this additional detector can be placed between the element 34 and 40 of Fig. 3 A, 3B or 3C, or is placed on the similar position place among aforementioned other embodiment.
Only be placed on and just have light can be on the catoptrical position of additional detector the time and incide on this detector and produce a signal as an object (except grating).If, just do not have signal to produce so shelter from light beam (thereby to additional detector reflected light) without any surface or finger or other objects.
According to a preferred embodiment of the present invention, laser instrument will be cut off when light that additional detector detected is lower than a certain threshold value.Light source will be periodically, for example every 100ms, and whether reclose a very short time has light to incide on the additional detector with check.If light incident is arranged, then light source will keep connecting to measure any motion that may exist.If do not detect light beam detection to very weak light, then light source will cut off a period of time once more.This process repeats to additional detector always and has detected the light signal that is higher than threshold value.In order to prevent spurious oscillation, preferably threshold value is introduced hysteresis characteristic.
Can make randomly that when in a predetermined period, for example in one minute or a few minutes, when not detecting motion, motion detector will enter one " sleep pattern ".In this pattern, light source is only connected the very short time (for example connection 50 of p.s. or every half second or 100ms).If detected motion in turn-on time, then motion detector forwards normal mode of operation to.
The preferred embodiment by various characteristics of many present invention of combining of the present invention and various aspects has illustrated the present invention.Should be appreciated that these characteristics and aspect can combined in various manners, and each embodiment of the present invention can comprise one or several aspect of the present invention.Category of the present invention is by following claim definition rather than by more above-mentioned specific preferred embodiment definition.In following claim, used entry " comprises ", the various tenses of " comprising " and they change and all mean " comprise but not necessarily be limited to ".
Claims (33)
1, a kind ofly be used for determining the method for an optical diffuser surface with respect to the relative motion of a measurement mechanism, it comprises:
Use incident illumination light irradiation surface, make a plurality of partial reflections of illumination light from the surface from a lasing light emitter;
Utilization is an optical grating diffraction partial illumination light of the part of this measurement mechanism, to form reference light;
Utilize this reference illumination light the light from this surface reflection to be carried out coherent detection, to form a signal as local oscillations light;
Determine to be parallel to the amount of relative motion on the surface of this grating according to this signal.
2, according to the process of claim 1 wherein the illumination light of surveying have a coherent length and wherein this grating be placed on neighbouring surface and sentence the spacing that makes between this grating and the surface less than this coherent length.
3, according to the method for claim 1, it comprises determines that this Surface Vertical is in the amount of the relative motion of this grating.
4, determine that according to the process of claim 1 wherein amount that this surface is parallel to the relative motion of this grating comprises the amount of determining not to be subjected to perpendicular to the motion of the influence of the motion of this grating.
5, according to each method among the claim 1-4, it comprises the amount of determining the motion of this surface in bidimensional.
6, according to each method among the claim 1-3, it comprises the amount of determining the motion of this surface in three-dimensional.
7, according to each method among the claim 1-4, it comprises the perception of determining this surperficial direction of motion.
8, according to each method among the claim 1-4, wherein this detection comprises that quadrature surveys.
9,, determine that wherein the amount of relative motion is based on catoptrical Doppler shift according to each method among the claim 1-4.
10, according to each method among the claim 1-4, it comprises the illumination light of polarization from surface reflection.
11, according to each method among the claim 1-4, wherein grating only produces the single-stage transillumination light of illumination surface basically.
12, according to each method among the claim 1-4, wherein incident illumination light is by linear polarizationization.
13, according to each method among the claim 1-4, wherein this surface is the optics diffuse reflection surface.
14,, wherein do not indicate the mark of position on the surface according to each method among the claim 1-4.
15, according to each method in the claim 11, wherein illumination light comprises visible illumination light.
16, according to each method among the claim 1-4, wherein illumination light comprises infrared illumination.
17, according to each method among the claim 1-4, it comprises the relative motion of surveying the surface on the both direction that is parallel to the surface.
18, a kind of optical mouse device, it comprises:
A housing that contains one towards the aperture on a surface; And
One monitors the optical motion detector that this is surperficial by this aperture, and wherein the optical motion detector utilizes each the method among the claim 1-4 to determine the motion of housing with respect to the surface.
19, a kind of touch indication device as control device, it comprises:
A housing that contains an aperture; And
An optical detector is used for determining that this aperture of process does the motion of the finger of translation, and wherein optical detector utilizes each the method among the claim 1-4 to determine this motion.
20, a kind of indicator device, it comprises:
The first touch indication device and a circuit that moves a pointer in response to the first indication device according to claim 19; And
Second touch according to claim 19 gives directions device and an energy to give directions device to make the circuit of screen scroll in response to second.
21, a kind of Genius mouse/touch indication device coupling apparatus that is used for computing machine, it comprises:
A housing that contains an aperture;
One according to each optical detector among the claim 1-4, is used for determining the motion of the object of a translation on the aperture; And
Be used for determining that this aperture is towards the top or towards the device of below.
22, a kind of scanner is used for reading this document by this scanner is moved on a file, and this scanner comprises:
An optical pick-up head, it can survey the pattern on the paper surface; And
An optical detector is used for determining scanner motion during translation on paper surface, and wherein optical detector utilizes each the method among the claim 1-4 to determine this motion.
23, according to the scanner of claim 22, wherein pattern comprises printed patterns.
24, according to the scanner of claim 21, wherein pattern is a handwritten pattern.
25, according to the scanner of claim 24, wherein pattern is a signature.
26, a kind of scrambler, it comprises:
An optics diffuse reflection surface that except reference marker, does not contain other marks; And
One has the optical detector of relative motion with respect to the surface, and wherein optical detector is measured with respect to this surperficial relative motion according to reference marker, and wherein optical detector has utilized each the method among the claim 1-4.
27, according to the scrambler of claim 26, wherein this surface is one around the surface of the dish of a rotation and the rotation of this dish of detector measurement.
28, a kind of virtual pen, it comprises:
Scrambler according to claim 26; And
A circuit is used for converting to the above-mentioned relative motion that records hand-written or graph data.
29, a kind of device that is used for mobile one page paper, it comprises:
The device that is used for mobile paper; And
An optical detector, the motion that it can not utilize any mark on the paper to measure paper,
Wherein optical detector has utilized each the method among the claim 1-4.
30, a kind of document scanner, it comprises
Device according to claim 29;
A reading head, it can be from the paper sense information; And
A storer, be used in response to the sheet movement that records information stores on the memory location.
31, a kind of printer, it comprises:
Device according to claim 29;
Storer wherein contains the information of ready-to-print to the paper; And
A printhead is used for coming type information according to the sheet movement that records.
32, a kind of facsimile recorder, it comprises a scanner according to claim 30.
33, a kind of facsimile recorder, it comprises a printer according to claim 31.
Applications Claiming Priority (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/IL1998/000113 WO1999046602A1 (en) | 1998-03-09 | 1998-03-09 | Optical translation measurement |
| ILPCT/IL98/00113 | 1998-03-09 | ||
| IL12430098A IL124300A0 (en) | 1998-03-09 | 1998-05-03 | Optical translation measurement |
| IL12543198A IL125431A0 (en) | 1998-03-09 | 1998-07-20 | Optical translation measurement |
| IL124300 | 1998-10-19 | ||
| IL125431 | 1998-10-19 | ||
| IL12665698A IL126656A0 (en) | 1998-03-09 | 1998-10-19 | Optical translation measurement |
| IL126656 | 1998-10-19 |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2003101027889A Division CN1548963A (en) | 1998-03-09 | 1999-03-09 | Optical translational measurement |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1256755A CN1256755A (en) | 2000-06-14 |
| CN1144063C true CN1144063C (en) | 2004-03-31 |
Family
ID=27452389
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2003101027889A Pending CN1548963A (en) | 1998-03-09 | 1999-03-09 | Optical translational measurement |
| CNB998002534A Expired - Lifetime CN1144063C (en) | 1998-03-09 | 1999-03-09 | Optical translation measurement |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2003101027889A Pending CN1548963A (en) | 1998-03-09 | 1999-03-09 | Optical translational measurement |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP1062519A2 (en) |
| JP (1) | JP3321468B2 (en) |
| CN (2) | CN1548963A (en) |
| AU (1) | AU750415B2 (en) |
| CA (1) | CA2322874A1 (en) |
| MX (1) | MXPA00009038A (en) |
| NZ (1) | NZ506914A (en) |
| WO (1) | WO1999046603A1 (en) |
Families Citing this family (47)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001042824A1 (en) * | 1999-12-08 | 2001-06-14 | Otm Technologies, Ltd. | Improved motion detector and components suitable for use therein |
| JP2001330431A (en) * | 2000-05-24 | 2001-11-30 | Sony Corp | Apparatus and method for measurement of characteristic of face shape |
| DE10139796A1 (en) * | 2001-08-14 | 2003-03-13 | Osram Opto Semiconductors Gmbh | Method and device for measuring translational movements between a surface and a measuring device |
| DE10147987B9 (en) * | 2001-09-28 | 2006-05-24 | Osram Opto Semiconductors Gmbh | Optoelectronic component |
| AU2003208299A1 (en) * | 2002-02-14 | 2003-09-04 | Forskningscenter Riso | Optical displacement sensor |
| CN1244044C (en) * | 2003-01-20 | 2006-03-01 | 张宏志 | Mouse optical signal treatment method and device |
| US7321359B2 (en) * | 2003-07-30 | 2008-01-22 | Avago Technologies Ecbu Ip (Singapore) Pte. Ltd. | Method and device for optical navigation |
| US20040227954A1 (en) * | 2003-05-16 | 2004-11-18 | Tong Xie | Interferometer based navigation device |
| US7116427B2 (en) | 2003-10-30 | 2006-10-03 | Avago Technologies Ecbu Ip (Singapore) Pte. Ltd. | Low power consumption, broad navigability optical mouse |
| SE0301825L (en) | 2003-06-19 | 2005-02-18 | Integration Diagnostics Ltd | Method and system for implant certification |
| JP4459725B2 (en) | 2003-07-08 | 2010-04-28 | 株式会社エヌ・ティ・ティ・ドコモ | Input key and input device |
| EP1503275A3 (en) * | 2003-07-30 | 2006-08-09 | Agilent Technologies Inc | Method and device for optical navigation |
| US6934037B2 (en) * | 2003-10-06 | 2005-08-23 | Agilent Technologies, Inc. | System and method for optical navigation using a projected fringe technique |
| US6985138B2 (en) | 2003-08-29 | 2006-01-10 | Motorola, Inc. | Input writing device |
| US7737947B2 (en) * | 2003-10-16 | 2010-06-15 | Avago Technologies Ecbu Ip (Singapore) Pte. Ltd. | Tracking motion using an interference pattern |
| US7492351B2 (en) | 2003-12-18 | 2009-02-17 | Avago Technologies Ecbu Ip (Singapore) Pte. Ltd. | Optical navigation based on laser feedback or laser interferometry |
| US7773070B2 (en) | 2004-05-21 | 2010-08-10 | Cypress Semiconductor Corporation | Optical positioning device using telecentric imaging |
| US7898524B2 (en) | 2005-06-30 | 2011-03-01 | Logitech Europe S.A. | Optical displacement detection over varied surfaces |
| US7399954B2 (en) | 2005-08-16 | 2008-07-15 | Avago Technologies Ecbu Ip Pte Ltd | System and method for an optical navigation device configured to generate navigation information through an optically transparent layer and to have skating functionality |
| FR2889874B1 (en) * | 2005-08-16 | 2007-09-21 | Commissariat Energie Atomique | METHOD FOR MEASURING THE TRAVEL SPEED |
| GB0522651D0 (en) * | 2005-11-07 | 2005-12-14 | Renishaw Plc | Scale and readhead system |
| US7765251B2 (en) | 2005-12-16 | 2010-07-27 | Cypress Semiconductor Corporation | Signal averaging circuit and method for sample averaging |
| US7737948B2 (en) | 2005-12-20 | 2010-06-15 | Cypress Semiconductor Corporation | Speckle navigation system |
| CN101401022B (en) * | 2006-02-06 | 2010-07-21 | 诺基亚公司 | Method and device for position sensing in an imaging system |
| US7636165B2 (en) * | 2006-03-21 | 2009-12-22 | Asml Netherlands B.V. | Displacement measurement systems lithographic apparatus and device manufacturing method |
| DE102006021017A1 (en) * | 2006-05-05 | 2007-11-08 | Dr. Johannes Heidenhain Gmbh | Position measuring device |
| US7528354B2 (en) * | 2006-06-05 | 2009-05-05 | Nokia Corporation | Method and device for position sensing of an optical component in an imaging system |
| US8541727B1 (en) | 2008-09-30 | 2013-09-24 | Cypress Semiconductor Corporation | Signal monitoring and control system for an optical navigation sensor |
| DE102008043540A1 (en) * | 2008-11-07 | 2010-05-12 | Dr. Johannes Heidenhain Gmbh | Optical position measuring device |
| US8711096B1 (en) | 2009-03-27 | 2014-04-29 | Cypress Semiconductor Corporation | Dual protocol input device |
| EP2348386A2 (en) * | 2010-01-21 | 2011-07-27 | Samsung SDI Co., Ltd. | Apparatus for detecting touch location |
| JP5590523B2 (en) * | 2010-03-17 | 2014-09-17 | 学校法人北里研究所 | Optical coherence tomography device |
| TWI401410B (en) * | 2010-04-26 | 2013-07-11 | Nat Univ Chung Hsing | Micro - shift optical measurement system |
| KR101376907B1 (en) * | 2011-12-16 | 2014-03-26 | 삼성전기주식회사 | Input device |
| DE102012203682B4 (en) * | 2012-03-08 | 2021-09-23 | Osram Gmbh | Projection device |
| CN103471508B (en) * | 2012-06-08 | 2016-06-01 | 上海微电子装备有限公司 | A kind of shear displacemant speckle measurement method and device |
| WO2016116810A1 (en) * | 2015-01-20 | 2016-07-28 | Otm Technologies Ltd. | Devices and methods for generating input |
| DE112015006593T5 (en) | 2015-06-04 | 2018-05-24 | Lumincode As | Position finder of a free space |
| WO2017195029A1 (en) * | 2016-05-11 | 2017-11-16 | Otm Technologies Ltd. | Devices and methods for determining relative motion |
| CN106289090B (en) * | 2016-08-24 | 2018-10-09 | 广东工业大学 | A kind of measuring device of dental resin planted agent variable field |
| CN107783676B (en) * | 2016-08-26 | 2021-01-01 | 东莞宝德电子有限公司 | Mouse pad, mouse input device and matching method of mouse and mouse pad |
| CN106556456A (en) * | 2016-11-22 | 2017-04-05 | 云南电网有限责任公司电力科学研究院 | A kind of converter valve tower vibrations monitoring system |
| US10627518B2 (en) * | 2017-06-02 | 2020-04-21 | Pixart Imaging Inc | Tracking device with improved work surface adaptability |
| JP2021164494A (en) * | 2018-07-02 | 2021-10-14 | ソニーグループ株式会社 | Medical observation system, medical observation apparatus, and method for driving medical observation apparatus |
| EP3623769A1 (en) * | 2018-09-12 | 2020-03-18 | Renishaw PLC | Measurement device |
| CN110971946B (en) * | 2018-09-30 | 2022-07-08 | 深圳Tcl新技术有限公司 | Television handwriting pen and control method thereof |
| US11333532B1 (en) * | 2020-12-10 | 2022-05-17 | Pixart Imaging Inc. | Light control circuit adapting to input signal frequency and operating method thereof |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5159406A (en) * | 1964-09-28 | 1992-10-27 | Zenith Electronics Corporation | Light-operated accelerometer-type techniques |
| DE2636211C2 (en) * | 1976-08-12 | 1978-01-26 | Ibm Deutschland Gmbh, 7000 Stuttgart | Interferometric method for distance or flatness measurement |
| GB2043387B (en) * | 1978-12-27 | 1983-05-05 | Marconi Co Ltd | Optical velocity measurement |
| DE3806608A1 (en) * | 1987-03-18 | 1988-09-29 | Deutsches Textilforschzentrum | METHOD FOR MEASURING THE SPEED AND / OR LENGTH OF ENDLESS TEXTILE TRACKS OF MATERIALS AND DEVICE FOR IMPLEMENTING THE METHOD |
| US5274361A (en) * | 1991-08-15 | 1993-12-28 | The United States Of America As Represented By The Secretary Of The Navy | Laser optical mouse |
| JP3083019B2 (en) * | 1993-03-05 | 2000-09-04 | キヤノン株式会社 | Optical device and speed information detecting device |
-
1999
- 1999-03-09 CA CA002322874A patent/CA2322874A1/en not_active Abandoned
- 1999-03-09 JP JP54555899A patent/JP3321468B2/en not_active Expired - Fee Related
- 1999-03-09 MX MXPA00009038A patent/MXPA00009038A/en unknown
- 1999-03-09 EP EP99907827A patent/EP1062519A2/en not_active Withdrawn
- 1999-03-09 NZ NZ506914A patent/NZ506914A/en unknown
- 1999-03-09 CN CNA2003101027889A patent/CN1548963A/en active Pending
- 1999-03-09 CN CNB998002534A patent/CN1144063C/en not_active Expired - Lifetime
- 1999-03-09 AU AU27439/99A patent/AU750415B2/en not_active Ceased
- 1999-03-09 WO PCT/IL1999/000137 patent/WO1999046603A1/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| WO1999046603B1 (en) | 1999-12-02 |
| JP2000508430A (en) | 2000-07-04 |
| EP1062519A2 (en) | 2000-12-27 |
| CN1548963A (en) | 2004-11-24 |
| MXPA00009038A (en) | 2002-06-04 |
| CN1256755A (en) | 2000-06-14 |
| NZ506914A (en) | 2002-12-20 |
| CA2322874A1 (en) | 1999-09-16 |
| AU750415B2 (en) | 2002-07-18 |
| WO1999046603A1 (en) | 1999-09-16 |
| AU2743999A (en) | 1999-09-27 |
| JP3321468B2 (en) | 2002-09-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1144063C (en) | Optical translation measurement | |
| CN1035454C (en) | Probe position measurement apparatus | |
| US6424407B1 (en) | Optical translation measurement | |
| CN1146717C (en) | Background compensation for confocal interference microscopy | |
| US7439484B2 (en) | Laser measurement apparatus using self-mixing effect | |
| CN1320363C (en) | Optical movement information detector and electronic equipment having same | |
| CN1249403C (en) | Displacement transducer | |
| US7732752B2 (en) | Continuous base beneath optical sensor and optical homodyning system | |
| CN1826518A (en) | System and method for measuring phase | |
| CN1667567A (en) | Coordinate input apparatus and its control method | |
| CN1657947A (en) | Optical movement information detector, movement information detection system, electronic equipment and encoder | |
| CN1580783A (en) | Velocimeter, displacement meter, vibrometer and electronic device | |
| CN1977144A (en) | Sensor device and stage device | |
| CN1591020A (en) | Optical velocimeter, displacement information measurement device and conveying and processing device | |
| Hansen | Mie scattering as a technique for the sizing of air bubbles | |
| US6844936B2 (en) | Device for the non-contacting measurement of an object to be measured, particularly for distance and/or vibration measurement | |
| CN1157653A (en) | Metrological stylus assembly | |
| US8098381B2 (en) | Fly height and slider protrusion measurement | |
| CN114964181B (en) | High-precision double-shaft laser level meter based on wavefront homodyne interference and measuring method | |
| CN1206640C (en) | Optical information memory storage and optical device | |
| Higurashi et al. | Nanometer-displacement detection of optically trapped metallic particles based on critical angle method for small force detection | |
| CN115164839B (en) | Wide-range double-shaft photoelectric level meter based on liquid lens | |
| Neudachina | Novel developments in SPM instrumentation: Interferometer displacement sensor and high-resolution video-rate AFM | |
| TW200923343A (en) | 3-DOF optical measurement probe with in-line beams | |
| JPH11257925A (en) | Sensor device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C53 | Correction of patent of invention or patent application | ||
| COR | Change of bibliographic data |
Free format text: CORRECT: APPLICANT; FROM: OTM TECHNOLOGIES LTD. TO: GRETEL CO., LTD. |
|
| CP03 | Change of name, title or address |
Address after: Israel Haierzelai Applicant after: OTM Technologies Ltd. Address before: Cyprus Nicosia Applicant before: Otm Technology Co. |
|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20040331 |