Patent EP0439804A2 successfully refreshed from Google Patents.
EP0439804A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Rotation detecting apparatus
Assignee: Canon Inc
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Filing: 1990-12-21
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Granted: —
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Expires: 2010-12-21
Abstract
Abstract An encoder includes a scale member provided on one body of two bodies which are relatively rotated and having gratings arranged in a relative rotating direction and a light irradiation means for irradiating a first region with beams. A diffracted image of the first regions is projected on a second region of the scale member. The encoder further includes a means for detecting the beams from the second region. The relative rotation of the other body is detected based on a detected result thereof. Disclosed is a scale whose relative rotation to the rotation detecting device is detected by its being irradiated with the beams from this device. The scale includes a base member formed with the grating having surfaces inclined to incident beams. Disclosed is a driving system for causing relative rotations of the two bodies. This system includes a means for relatively rotationally driving the two bodies and a control means for controlling a driving condition of the driving means. Disclosed is a motor unit including a motor module having its body whose rotation is detected by a result of a light irradiation means and rotary shaft provided with a scale member. This unit further includes a means for integrally supporting the body, the light irradiation means and the detecting means.
Inventors
- 👤 Masahiko C/O Canon Kabushiki Kaisha Igaki
- 👤 Yoshifumi C/O Canon Kabushiki Kaisha Nishimoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 22:20
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/26; G01D5/32; G01D5/34; G01D5/36
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
137 words
A rotation detecting apparatus for detecting relative rotation of two bodies, comprising: a scale member provided on said one body and formed with gratings arranged in a direction of a relative rotation to extend in a direction of a rotary axis of the relative rotation; a light irradiation means for irradiating a first region formed with said gratings of said scale member with beams, a diffracted image of said first region irradiated with the beams from said light irradiation means being projected on a second region formed with said gratings of said scale member; and a detecting means for detecting the beams from said second region on which said diffracted image is projected, the relative rotation of said scale member with respect to said other body being detected based on a detected result of said detecting means.
Claim 2
Dependent Claim
51 words
An apparatus according to claim 1, wherein said scale member is a cylindrical body and makes relative rotations about a rotary axis parallel to the generatrix of the cylinder, and said gratings are formed in the direction of the relative rotation of said scale member on a cylindrical side surface thereof.
Claim 3
Dependent Claim
32 words
An apparatus according to claim 1, wherein said gratings are so formed that transmitting portions and shading portions are alternately arranged in the direction of the relative rotation of said scale member.
Claim 4
Dependent Claim
49 words
An apparatus according to Claim 3, wherein said scale member assumes a cylindrical shape, said light irradiation means effects irradiation from outside of said scale member, said diffracted image is formed by the beams penetrating said first region, and said detecting means receives the beams penetrating said second region.
Claim 5
Dependent Claim
34 words
An apparatus according to claim 1, wehrein said gratings are so formed that rugged portions having surfaces inclined to incident beams are arranged in the direction of the relative rotation of said scale member.
Claim 6
Dependent Claim
60 words
An apparatus according to claim 5, wehrein said scale member assumes the cylindrical shape, at least portions formed with said gratings have a transmissive property, said light irradiation means effect irradiation from outside of said scale member, said diffracted image is formed by the beams penetrating said first region, and said detecting means receives the beams penetrating said second region.
Claim 7
Dependent Claim
26 words
An apparatus according to claim 5, wherein said detecting means has at least two pieces of light receiving elements for obtaining periodic signals exhibiting different phases.
Claim 8
Dependent Claim
34 words
An apparatus according to claim 7, wehrein at least said two light receiving elements obtain the periodic signals exhibiting the different phases by receiving the beams emitted in different directions from said second region.
Claim 9
Dependent Claim
53 words
An apparatus according to claim 7, further comprising a means for discerning the direction of the relative rotation of said scale member on the basis of the periodic signals exhibiting the different phases and/or a means for effecting a signal interpolating process on the basis of the periodic signals exhibiting the difference phases.
Claim 10
Dependent Claim
30 words
An apparatus according to claim 7, wherein said scale member is composed of a transparent body, and said gratings are formed by providing sectionally V-shaped grooves on said transparent body.
Claim 11
Dependent Claim
51 words
An apparatus according to claim 1, wherein said scale member is a hollow body, said light irradiation means effects the irradiation from inside of said hollow body, said diffracted image is formed by the beams reflected by said first region, and detecting means receives the beams reflected by said second region.
Claim 12
Dependent Claim
23 words
An apparatus according to claim 11, said gratings include V-shaped grooves or protrusions periodically arranged on an inner periphery of said hollow body.
Claim 13
Dependent Claim
23 words
An apparatus according to Claim 11, wherein said light irradiation means includes a reflection member for directing the beams to said first region.
Claim 14
Dependent Claim
33 words
An apparatus according to claim 11, wherein said detecting means includes a reflection member for directing the beams emerging from a light receiving element and said second region to said light receiving element.
Claim 15
Dependent Claim
30 words
An apparatus according to claim 1, wherein at least a portion having a refractive index larger than the air intervenes in a light path between said first and second regions.
Claim 16
Dependent Claim
45 words
An apparatus accoridng to claim 15, wherein said scale member assumes the cylindrical shape, said gratings are formed on a cylindrical side surface, and a member having a refractive index larger than the air intervenes in the light path inwardly of said cylindrical scale member.
Claim 17
Dependent Claim
27 words
An apparatus according to claim 1, wherein said scale member includes a fitting portion fitted to a body the relative rotation of which is to be detected.
Claim 18
Dependent Claim
58 words
An apparatus according to claim 1, wherein a diameter d of said scale member satisfies the following formula: (N- (1/4)) P² / λ < d < (N+ (1/4)) P² / λ where P is the pitch of said gratings, λ is the wavelength of the beams emerging from said light irradiation means, and N is the natural number.
Claim 19
Independent Claim
29 words
An apparatus according to cliam 16, said pitch P satisfies the following formula: P = πd/n where n is the total number of said transmitting portions of said gratings.
Claim 20
Dependent Claim
24 words
An apparatus according to claim 1, further comprising a marker element, provided at a part of said scale member, for detecting a reference position.
Claim 21
Dependent Claim
52 words
An apparatus according to claim 20, further comprising a marker element irradiation means for irradiating said marker element with the beam, and a reference position detecting means for detecting that said scale is in a relative rotational position serving as the reference by detecting the beam emitted from said marker irradiation means.
Claim 22
Dependent Claim
33 words
An apparatus according to claim 21, wherein said marker irradiation means includes a branching means for branching the beams from said light irradiation means and directing the branched beam to said marker element.
Claim 23
Dependent Claim
132 words
A rotation detecting apparatus for detecting a relative rotation with respect to a body formed with gratings in a direction of the relative rotation, comprising: a light irradiation means for irradiating, with beams, a first region formed with said gratings of said body, said gratings arranged in the direction of the relative rotation to extend in a direction of a rotary axis of the relative rotation, a diffracted image of said first region irradiated with the beams from the said light irradiation means being projected on a second region formed with said gratings of said body; and a detecting means for detecting the beams from said second region on which said diffracted image is projected, the relative rotation to said body being detected based on a detected result of said detecting means.
Claim 24
Dependent Claim
21 words
An apparatus according to claim 23, further comprising a unit provided integrally with said light irradiation means and said detecting means.
Claim 25
Dependent Claim
38 words
An apparatus according to claim 24, wherein said unit includes said light irradiation means disposed to effect the irradiation from outside of said body and said detecting means disposed to detect the beam emitted outwardly of said body.
Claim 26
Dependent Claim
44 words
An apparatus according to claim 24, wherein said unit includes said light irradiation means disposed to effect the irradiation from inside of a hollow body serving as said body and said detecting means disposed to detect the beams emitted inwardly of said hollow body.
Claim 27
Dependent Claim
41 words
An apparatus according to claim 23, wherein said detecting means includes a plurality of photodetectors for detecting each of the beams emitted in a plurality of directions from said second region, and said photodetectors respectively obtain periodic signals exhibiting different phases.
Claim 28
Dependent Claim
157 words
A scale irradiated with beams by a rotation detecting apparatus, a relative rotation of said scale with respect to said rotation detecting device being detected based on an emitted-beam detected result by said rotation detecting device, comprising: a base member fitted to a body whose relative rotation to said rotation detecting device is detected; and gratings arranged on said base member in the direction of the relative rotation to extend in a direction of a rotary axis of the relative rotation, said gratings being formed by arranging rugged portions having surfaces inclined to incident beams in the direction of the relative rotation of said base member, wherein when a first region formed with said gratings is irradiated with beams, a diffracted image of said first region is projected on a second region formed with said gratings, and the relative rotation of said scale is detected based on a detected result of the beams from said second region.
Claim 29
Dependent Claim
32 words
A scale according to claim 28, wherein said gratings are so formed that sectionally V-shaped arranged in a plurality of lines in the direction of the relative rotation of said base member.
Claim 30
Dependent Claim
25 words
A scale according to claim 29, wherein said plurality of grooves are so arranged that virtually non-oblique portions to the incident beams are interposed therebetween.
Claim 31
Dependent Claim
29 words
A scale according to claim 30, wherein each width of said groove and said non-oblique portion is P/2, where P is the pitch at which said grooves are arranged.
Claim 32
Dependent Claim
34 words
A scale according to claim 30, wherein the width of said groove is 2P/3, while the width of said non-oblique portion is P/3, where P is the pitch at which said grooves are arranged.
Claim 33
Dependent Claim
142 words
A driving system for causing two bodies to make relative rotations, comprising: a driving means for relatively rotationally driving said two bodies; a scale member provided on said one body and formed with gratings arranged in a direction of the relative rotation to extend in a direction of a rotary axis of the relative rotation; a light irradiation means for irradiating a first region formed with said gratings with beams, a diffracted image of said first region irradiated with the beams by said light irradiation means being projected on a second region formed with said gratings of said scale member; a detecting means for detecting the beams from said second region on which said diffracted beam is projected; and a control means for controlling a driving condition by said driving means on the basis of a detected result by said detecting means.
Claim 34
Dependent Claim
36 words
A driving system according to claim 33, further comprising a setting means for setting a driving condition developed by said control means performing the control on the basis of the detected result by said detecting means.
Claim 35
Dependent Claim
21 words
A driving system according to claim 34, wherein said gratings are formed by providing sectionally V-shaped grooves on said scale member.
Claim 36
Dependent Claim
39 words
A driving system according to claim 35, wherein said detecting means includes a plurality of light receiving elements, for receiving the beams emitted from said second region in different directions, from which periodic signals exhibiting different phases are obtained.
Claim 37
Dependent Claim
122 words
A rotation detecting apparatus for detecting relative rotations of two bodies; comprising: a scale fitted to said one body and formed with gratings arranged in a direction of the relative rotation to extend in a direction of a rotary axis of the relative rotation; a light source for irradiating a first region formed with said gratings with beams, a diffracted image of said first region irradiated with the beams by said light source being projected on a second region formed with said gratings of said scale; detectors for detecting the beams from said second region on which said diffracted image is projected, the relative rotation of said scale to said other body being detected based on a detected result by said detector.
Claim 38
Dependent Claim
20 words
An apparatus according to claim 37, wherein said gratings are formed by providing sectionally V-shaped grooves on said scale member.
Claim 39
Dependent Claim
39 words
An apparatus according to claim 38, wherein said plurality of detectors are provided to respectively receive the beams emitted from said second region in different directions, and periodic signals exhibiting different phases from said plurality of detectors are obtained.
Claim 40
Dependent Claim
123 words
A rotation detecting apparatus for detecting a relative rotation to a body formed with gratings arranged in a direction of the relative rotation, comprising: a light source for irradiating, with beams, a first region formed with said gratings of said body having said gratings arranged in the direction of the relative rotation to extend in a direction of a rotary axis of the relative rotation, a diffracted image of said first region irradiated with the beams by said light source being projected on a second region formed with said gratings; and detectors for detecting the beams from said second region on which said diffracted image is projected, said detectors giving a detected result from which the relative rotation to said body is detected.
Claim 41
Dependent Claim
39 words
An apparatus according to claim 40, wherein said plurality of detectors are provided to respectively receive the beams emitted from said second region in different directions, and periodic signals exhibiting different phases are obtained from said plurality of detectors.
Claim 42
Dependent Claim
147 words
A motor unit comprising: a motor module, including a body and a rotary shaft, for giving rotational driving; a scale member provided on said rotary shaft and formed with gratings arranged in a direction of a relative rotation to extend in a direction of a rotary axis of the relative rotation; a light irradiation means for irradiating a first region formed with said gratings with beams, a diffracted image of said first region irradiated with the beams by said light irradiation means being projected on a second region formed with said gratings of said scale member; a detecting means for detecting the beams from said second region on which said diffracted image is projected, said detecting means giving a detected result from which the rotation of said rotary shaft is detected; and a suppoorting means for integrally supporting said body, said irradiation means and said detecting means.
Claim 43
Dependent Claim
21 words
A motor unit according to claim 42, wherein said gratings are formed by providing sectionally V-shaped grooves on said scale member.
Claim 44
Dependent Claim
46 words
A motor unit according to claim 43, wherein said detecting means includes a plurality of light receiving elements for respectively receiving the beams emitted from said second region in different directions, and periodic signals exhibiting different phases are obtained from said plurality of light receiving elements.
References Cited (Backward Citations)
No citation records indexed.
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