Patent EP0304893A2 successfully refreshed from Google Patents.
EP0304893A2
Expired / Lapsed
EP
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Encoder
Assignee: Canon Inc
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Filing: 1988-08-24
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Granted: —
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Expires: 2008-08-24
Abstract
Abstract An encoder includes an electrically conductive reference scale having surface steps formed at predetermined positions; an electrically conductive probe having a tip disposed opposed to the reference scale; wherein the reference scale and the probe are relatively movable in a direction different from the opposing direction of the tip of the probe and the reference scale; a portion for applying an electric voltage to between the reference scale and the probe; a portion for detecting a change in a tunnel current between the reference scale and the probe, to between which the electric voltage is applied by the voltage applying portion at the time of the relative movement between the scale and the probe, the detecting portion detecting the change in the tunnel current when the probe passes a position opposed to a surface step of the reference scale; and portion for detecting the amount of the relative movement between the scale and probe, on the basis of the detection by the change detecting portion.
Inventors
- 👤 Yoshihiro Yanagisawa
- 👤 Yuko Morikawa
- 👤 Hiroshi Matsuda
- 👤 Haruki Kawada
- 👤 Kunihiro Sakai
- 👤 Hisaaki Kawade
- 👤 Ken Eguchi
- 👤 Eigo Kawakami
- 👤 Toshimitsu Kawase
- 👤 Minoru Yoshii
- 👤 Kenji Saitoh
- 👤 Akihiko Yamano
- 👤 Hiroyasu Nose
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 17:09
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/12; G01D5/244; G01B; G01B7/00; G01B7/003; G01D5/245; G01D5/2451; G11; G11B; G11B9/00; G11B9/12; G11B9/14; G11B9/1418; G11B9/1427; G11B9/1463; G11B9/1472; G11B9/1481; B; B82; B82Y; B82Y10/00; G01Q; G01Q10/00; G01Q10/04; G01Q10/06; G01Q60/00; G01Q60/10; G01Q60/16; G01Q80/00; Y; Y10; Y10S; Y10S977/00; Y10S977/84; Y10S977/849; Y10S977/85; Y10S977/851; Y10S977/86; Y10S977/861; Y10S977/902; Y10S977/932; Y10S977/943; Y10S977/947
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
163 words
An encoder, comprising: an electrically conductive reference scale having surface steps formed at predetermined positions; an electrically conductive probe having a tip disposed opposed to said reference scale; wherein said reference scale and said probe are relatively movable in a direction different from the opposing direction of said tip of said probe and said reference scale; means for applying an electric voltage to between said reference scale and said probe; means for detecting a change in a tunnel current between said reference scale and said probe, to between which the electric voltage is applied by said voltage applying means at the time of the relative movement between said scale and said probe, said detecting means detecting the change in the tunnel current when the probe passes a position opposed to a surface step of said reference scale; and means for detecting the amount of the relative movement between said scale and probe, on the basis of the detection by said change detecting means.
Claim 2
Dependent Claim
163 words
An encoder, comprising: an electrically conductive reference scale having surface steps formed at predetermined positions; an electrically conductive probe having a tip disposed opposed to said reference scale; wherein said reference scale and said probe are relatively movable in a direction different from the opposing direction of said tip of said probe and said reference scale; means for applying an electric voltage to between said reference scale and said probe; means for detecting a change in a tunnel current between said reference scale and said probe, to between which the electric voltage is applied by said voltage applying means at the time of the relative movement between said scale and said probe, said detecting means detecting the change in the tunnel current when the probe passes a position opposed to a surface step of said reference scale; and means for detecting the amount of the relative movement between said scale and probe, on the basis of the detection by said change detecting means.
Claim 3
Dependent Claim
37 words
An encoder according to Claim 1, wherein said amount detecting means detects the amount of the relative movement on the basis of the amount of change in the tunnel current as detected by said change detecting means.
Claim 4
Dependent Claim
78 words
An encoder according to Claim 1, wherein said amount detecting means includes means for moving at least one of said reference scale and said probe in said opposing direction on the basis of the amount of change in the tunnel current as detected by said change detecting means, and means for detecting the amount of the relative movement between said reference scale and said probe on the basis of the amount of movement made by said moving means.
Claim 5
Dependent Claim
72 words
An encoder according to Claim 1, further comprising means for relatively oscillating said reference scale and said probe in a direction different from said opposing direction, and means for detecting the direction of the relative movement between said reference scale and said probe on the basis of a change in phase of the change in the tunnel current between the reference scale and said probe being relatively oscillated by said oscillating means.
Claim 6
Dependent Claim
60 words
An encoder according to Claim 1, further comprising means bearing positional information and being provided on one of said reference scale and said probe at a pitch larger than the pitch of said surface step, and means for roughly detecting the amount of the relative movement between said reference scale and said probe on the basis of the positional information.
Claim 7
Dependent Claim
114 words
An encoder according to Claim 1, further comprising first position detecting means for detecting first and second scales, provided for rough detection of the amount of relative movement between relatively movable first and second objects, for detecting the amount of the relative movement between the first and second objects, wherein one of said reference scale and said probe is provided on said first object and the other is provided on one of said second scale and said first position detecting means and wherein, for fine detection of the amount of the relative movement between the first and second objects, the amount of the relative movement between said reference scale and said probe is detected.
Claim 8
Dependent Claim
181 words
A relative position detecting device for detecting the positional relation between first and second objects in a predetermined direction, said device comprising: an electrically conductive reference scale having positional information for each predetermined position of said first object; an electrically conductive probe disposed on said second object and having a tip opposed to said reference scale; wherein said reference scale and said probe are opposed to each other in a direction different from said predetermined direction: means for applying an electric voltage to between said reference scale and said probe; means for detecting a change in a tunnel current between said reference scale and said probe, to between which the voltage is applied by said voltage applying means when said reference scale and said probe relatively move in said predetermined direction, said change detecting means detecting the change in the tunnel current when said probe passes a position opposed to said positional information; and means for detecting the positional relation in said predetermined direction between said first and second objects, on the basis of the detection by said change detecting means.
Claim 9
Dependent Claim
181 words
A relative position detecting device for detecting the positional relation between first and second objects in a predetermined direction, said device comprising: an electrically conductive reference scale having positional information for each predetermined position of said first object; an electrically conductive probe disposed on said second object and having a tip opposed to said reference scale; wherein said reference scale and said probe are opposed to each other in a direction different from said predetermined direction: means for applying an electric voltage to between said reference scale and said probe; means for detecting a change in a tunnel current between said reference scale and said probe, to between which the voltage is applied by said voltage applying means when said reference scale and said probe relatively move in said predetermined direction, said change detecting means detecting the change in the tunnel current when said probe passes a position opposed to said positional information; and means for detecting the positional relation in said predetermined direction between said first and second objects, on the basis of the detection by said change detecting means.
Claim 10
Dependent Claim
43 words
A device according to Claim 7, further comprising a recording medium provided on said first object, and means for recording or reproducing information at a predetermined position on said recording medium, on the basis of the detection by said positional relation detecting means.
Claim 11
Dependent Claim
67 words
A device according to Claim 8, wherein said recording means has an electric memory effect and wherein said information recording or reproducing means includes an electrically conductive second probe having a tip disposed opposed to said recording medium and means for applying an electric voltage to between said probe and said information recording or reproducing means, said second probe being used for the information recording or reproducing.
Claim 12
Dependent Claim
44 words
A device according to Claim 8, wherein said recording medium has an electric memory effect, wherein said reference scale is provided on said recording medium and wherein said information recording or reproducing means effects the information recording or reproducing by use of said probe.
Claim 13
Dependent Claim
18 words
A device according to Claim 10, wherein said reference scale has a two-dimensional pattern which contains positional information.
References Cited (Backward Citations)
No citation records indexed.
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