Canon Kabushiki Kaisha

Koh Ishizuka

Tetsuharu Nishimura

Satoshi Ishii

Masaaki Tsukiji

Yasushi Kaneda

Yoichi Kubota

Hiroshi Kondo

Osamu Kasahara

Hiroyasu Nose

Minoru Yoshii

Masahiko Igaki

Tadashi Eguchi

Seiji Takeuchi

Shigeki Kato

Masaru Nyui

Chikara Satoh

Kenji Hisamoto

Kotaro Hosaka

Katsumi Momose

Hiroji Narumi

A displacement information detection apparatus includes a light generation unit, a first unit including a first grating for displacement information detection and one or more lens members for original detection, and a second unit including a second grating for displacement detection, which cooperates with the first grating, and an origin detection mark. The apparatus also includes at least one first light-receiving element for receiving light generated by the light generation unit and propagated via the first and second gratings, and outputting a signal including relative displacement information between the first and second units. The apparatus also includes one or more second light-receiving elements for receiving light generated by the light generation unit and propagated via the lens member. The second light-receiving elements output a signal indicating an origin based on a change in light-receiving state when the origin detection mark is present in the optical path of light leaving the lens member.

Displacement information detection apparatus

A displacement detection apparatus includes a light source (1), a first diffraction grating (G1) which is arranged on the same substrate as a second diffraction grating (G2) so as to diffract and split light emitted from the light source and to irradiate .+-.1st-order diffracted light beams onto the second diffraction grating (G2), a third diffraction grating (G3) for synthesizing a +1st-order reflectively diffracted light beam generated by reflectively diffracting the +1st-order diffracted light beam by the second diffraction grating, and a -1st-order reflectively diffracted light beam generated by reflectively diffracting the +1st-order diffracted light beam by the second diffraction grating to form interference light, and a light-receiving element (3) for converting the interference light into a signal representing a displacement of the substrate.

Apparatus for optically detecting displacement of an object using a

A rotary encoder has a disk with fine gratings comprising diffraction gratings of small diameters and a high density. Two diffraction lights of predetermined orders which are obtained when a light beam is irradiated to the fine gratings, are interfered properly with each other, thereby enabling rotational information of a rotary object to be detected at a high resolution while realizing a small and thin size of the overall apparatus.

Rotary encoder measuring substantially coinciding phases of interference

An apparatus for detecting information relating to displacement of an object on which a grating scale is affixed. The apparatus includes a beam-emitting system for irradiating the grating scale with a beam. The apparatus also includes a light-detecting element having a light-receiving surface. A grating portion is integrally formed on at least a part of the light-receiving surface for detecting a beam from the grating scale which is irradiated by the beam from the beam-emitting system. Information relating to displacement of the object is detected on the basis of the detection by the grating portion of the light-detecting element.

Apparatus including a light-detecting element having a photo-electric

An apparatus for measuring the relative displacement information between it and a scale on which a diffraction grating is formed has a light source, a separating device for separating a light beam from the light source into a plurality of light beams, a wave combining device for wave-combining the diffracted lights of the plurality of light beams separated by the separating device which are diffracted by the diffraction grating, a light receiver for receiving the interfering lights by the plurality of light beams wave-combined by the wave combining device, the relative displacement information between the apparatus and the scale being measured by the light reception of the light receiver, and an optical device adapted to collimate the plurality of light beams or to form a spherical wave having so large a radius of curvature that it can be regarded as a plane wave of the plurality of light beams in the direction of light beam separation of the separating device and to condense the plurality of light beams in the optical path from the separating device to the wave combining device in a direction perpendicular to the direction of light beam separation.

Apparatus for measuring relative displacement between the apparatus and

A displacement detection apparatus has a light source 1, a first diffraction grating G1 for diffracting and dividing the light from the light source and applying O-order diffracted light and +1st-order diffracted light to a second diffraction grating G2, a third diffraction grating G3 for combining +1st-order reflected diffracted light created by the O-order diffracted light being reflected and diffracted by the second diffraction grating and -lst-order reflected diffracted light created by the +lst-order diffracted light being diffracted by the second diffraction grating, to thereby form interference light, and a light receiving element 3 for photoelectrically converting the interference light, the third diffraction grating including four diffraction gratings given a phase difference of .pi./2 each, the light receiving element being provided with light receiving portions 3a1, 3a2, 3b1 and 3b2 corresponding to the four diffraction gratings of the third diffraction grating, and cruciform light intercepting means is provided between adjacent ones of the light receiving portions.

Displacement detection apparatus using multiple displacement detection

An apparatus for detecting a displacement of a diffraction grating set on a measured object, comprises a light-emitting device, a separation optical element for separating a beam from the light-emitting device into a plurality of beams, a multiplexing optical element for multiplexing light beams diffracted by the diffraction grating from two beams out of the plurality of beams, a first detecting unit for detecting interference light generated when the beams of diffracted light are multiplexed by the multiplexing optical element and outputting a signal related to relative displacement information to the diffraction grating, and a second detecting unit for outputting a signal related to different information from the relative displacement information to the diffraction grating, based on a change in a diffracted light quantity of diffracted light by the diffraction grating from another beam out of the plurality of beams and/or another diffracted light by the diffraction grating from the two beams.

Optical displacement sensor

A device for detecting the position of an information recording or reproducing head relative to a recording medium; the head is relatively rotatable around a first axis with respect to the recording medium, and rotatable around a second axis parallel to the first axis. The device includes an autocollimator for measuring a relative positional relationship of the head substantially along the direction of the rotation around the second axis, a rotating table on which either the combination of the recording medium and the head or the autocollimator is mounted to activate the rotational movement substantially around the second axis, and a control unit. The control unit rotates the rotating table in response to the obtained position of the head with respect to the recording medium. According to the measurement result by the autocollimator, the control unit accomplishes a relative positional controlling in which a relative positional relationship between the autocollimator and the head is kept constant. As a result, a compact and high-accuracy head positioning device is achieved.

Head positioning using a disk drive mounted to a rotating table

A velocity information detecting apparatus detects velocity information of a moving object. The apparatus is provided with a light source for emitting a coherent beam, a beam splitting member for splitting the beam from the light source into a plurality of beams to irradiate the object thereby, and a photodetector for receiving scattered light from the object. The velocity information of the object is detected, based on a Doppler shift of the scattered light detected by the photodetector. The plurality of beams irradiate the object disposed in a region before the plurality of beams are spatially separated from each other. The beam splitting member may be either a diffraction grating or a prism member. The diffraction grating may be a lamellar phase grating or a blazed diffraction grating. The prism member may be a roof prism.

Velocity information detecting apparatus

A rotation detecting apparatus includes a grating portion provided on one of two objects for which relative rotation is to be detected, a light-emitting portion provided on the other of the two objects, and a light-receiving portion provided on the other object. The grating portion has at least one multi-helix diffraction grating. The light-receiving portion receives a beam emitted from the light-emitting portion and then traveling by way of the multi-helix diffraction grating. Information of relative rotation of the two objects is detected through light reception of the light-receiving portion.

Rotation detecting apparatus and scale having a multi helix diffraction

A rotary detector has a diffraction grating arranged circumferentially and a center at substantially the center of rotation. The rotary detector measures rotational information of a rotating object. The rotary detector is provided with a light source, an irradiating optical system for irradiating luminous flux from the light source to a first point on the diffraction grating, and an optical system for guiding two diffracted luminous fluxes emerging from the first point at an emerging angle and diffracted to have a same order but different signs to be incident at a second point on the diffraction grating at an incident angle relative to a rotational direction of the grating, with the second point positioned substantially opposite to the first point on the diffraction grating with respect to the center of the rotation, and the incident angle is the same angle as the emerging angle. A wave superposing optical system superposes two rediffracted lights diffracted at the second point with the order of the same signs at the first point, respectively, and a detector detects the superposed rediffracted lights. The rotational information of the rotating object is thus measured by the detector.

Rotary detector having an optical system for guiding two diffracted

An apparatus for detecting information as for the rotation of a scale having a diffraction grating arranged thereon along a direction of detection of the rotation is constituted by a light source portion for irradiating a light beam onto a first point on the diffraction grating of said scale wherein said light source portion emitting two diffracted lights having a predetermined order from the first point by the irradiation of the light beam, a transparent substrate to be parallelly arranged in the vicinity of the surface of said scale and having a plurality of optical elements arranged thereon, said plurality of optical elements directing the two diffracted lights of the predetermined order to a second point other than said first point on the diffraction grating of said scale and a photo-detector for detecting an interference light beam of the diffracted lights generated out of said second point on which the two diffracted lights of the predetermined order are incident whereby the information on the rotation of said scale relative to the photo-detector is detected by the photo-detection by said photo-detector.

Rotation information detection apparatus

A displacement detection apparatus comprises a light source 1, a first diffraction grating including a blazed grating for diffracting and splitting light from the light source to irradiate a 0-order diffraction light and a +1-order diffraction light to a second diffraction grating, a third diffraction grating including a blazed grating for combining a +1-order reflected diffraction light produced by the reflection and diffraction of the 0-order diffraction light by the second diffraction grating and a -1-order reflected diffraction light produced by the diffraction of the +1-order diffraction light by the second diffraction grating to produce an interference light, and a photo-sensing element for converting the interference light to a signal representing a change in the second diffraction grating.

Displacement detection apparatus

This invention relates to a light-emitting apparatus, a photosemiconductor apparatus and a method for producing a photosemiconductor wherein the light-emitting apparatus for emitting light on an object comprises a substrate; a light-emitting element provided on the substrate; an optical member provided on a predetermined position to the substrate; a light-receiving element provided on the substrate, the light-receiving element receiving a part of light beam emitted from the light-emitting element on the object via the optical member; and means for controlling a quantity of the beam projected from the light-emitting element on the object, based on an output signal from the light-receiving element.

Growing community of inventors

Urawa, Japan

Koh Ishizuka