Abstract: An optical encoder is provided that can reduce the effects of unwanted diffracted light in a stable manner. The optical encoder 1 comprises a scale 2 and a detection head 3. The detection head 3 includes a light source 4 and light-receiving means 6 with a light-receiving surface 60. The light-receiving surface 60 has an element row 7 with multiple light-receiving elements 70 arranged along the measurement direction with the same period as that of the interference fringes. Here, an error included in detection signals generated from the interference fringes, with such error being caused by the fact that the number of light-receiving elements 70 is an odd number, will be referred to as a number-of-elements-induced error, and a predetermined allowable error will be referred to as an allowable error. The number of light-receiving elements 70 in the element row 7 is set to be a number where the number-of-elements-induced error is smaller than the allowable error.

Abstract: An encoder includes scale and detection head. The detection head includes light source (transmitting unit) and light-receiving unit (receiving unit). The light-receiving unit includes light-receiving surface (receiving surface) and converts light received at the light-receiving surface 50 into differential detection signals with two phases and outputs the same. The light-receiving surface includes element array group including four element arrays provided in a parallel manner along an orthogonal direction, with each element array including a plurality of light-receiving elements (receiving elements). The plurality of element arrays in the element array group are disposed at positions where the sum of: (i) a distance in the orthogonal direction from a reference position to a positive phase signal element array; and (ii) a distance in the orthogonal direction from the reference position to the negative phase signal element array, is the same for all the phases of the at least two phases.

Abstract: A displacement sensor includes a radiation part that irradiates a workpiece displaceable in a predetermined displacement direction with light, a light receiving part that receives a reflected light generated when the light radiated by the radiation part is reflected on the workpiece, and a fringe generation part that includes a generation means for generating fringes on a light receiving surface of the light receiving part when the light receiving part receives the reflected light from the workpiece. The fringe generation part and the light receiving part are arranged such that the fringe generation part and the light receiving part are parallel to the displacement direction, or parallel to a virtual image of the displacement direction.

Abstract: An optical displacement sensor includes: a splitting unit that splits the light radiated from the light source into a first light ray and a second light ray; a reflection unit including a first reflection part and a second reflection part provided at a predetermined angle with respect to the first reflection part; and a fold-back reflection unit that folds-back and reflects the light that has gone through the reflection unit to the reflection unit. The optical displacement sensor is characterized in that the reflection unit reflects the first light ray and the second light ray that are split by the splitting unit and have gone through the diffraction unit from the first reflection part to the second reflection part, and reflects the first light ray and the second light ray that are reflected by the fold-back reflection unit from the second reflection part to the first reflection part.

Abstract: An encoder is provided that is capable of suppressing accuracy deterioration even if a scale is disposed in a tilted manner with respect to a receiving unit by being rotated around an axis (i.e., a rotation axis) orthogonal to a receiving surface. The encoder 1 includes scale 2 and detection head 3. The detection head 3 includes light source (transmitting unit) 4 and light-receiving unit (receiving unit) 5. The light-receiving unit includes light-receiving surface (receiving surface) 50 and converts light received at the light-receiving surface 50 into differential detection signals with two phases and outputs the same. The light-receiving surface 50 includes element array group 7 including four element arrays 71-74 provided in a parallel manner along an orthogonal direction, with each element array 71-74 including a plurality of light-receiving elements (receiving elements) 500.

Abstract: A displacement sensor includes a radiation part that irradiates a workpiece displaceable in a predetermined displacement direction with light, a light receiving part that receives a reflected light generated when the light radiated by the radiation part is reflected on the workpiece, and a fringe generation part that includes a generation means for generating fringes on a light receiving surface of the light receiving part when the light receiving part receives the reflected light from the workpiece. The fringe generation part and the light receiving part are arranged such that the fringe generation part and the light receiving part are parallel to the displacement direction, or parallel to a virtual image of the displacement direction.

Abstract: The optical angle sensor comprises a diffraction unit, a light source, a light receiving unit, and a plurality of reflection units. The diffraction unit includes a first diffraction part for generating combined light and a second diffraction part for diffracting a first light and a second light a plurality of times. The plurality of reflection units includes a first reflection unit, a second reflection unit, a third reflection unit that reflects the first light and the second light through the second diffraction part toward the second diffraction part, fourth reflection unit, and fifth reflection unit. The calculating unit, with the rotation of the diffraction unit, calculates the amount of change in the angle based on the change in the interference signal caused by the combined light generated on the light receiving surface.

Abstract: An optical displacement sensor includes: a splitting unit that splits the light radiated from the light source into a first light ray and a second light ray; a reflection unit including a first reflection part and a second reflection part provided at a predetermined angle with respect to the first reflection part; and a fold-back reflection unit that folds-back and reflects the light that has gone through the reflection unit to the reflection unit. The optical displacement sensor is characterized in that the reflection unit reflects the first light ray and the second light ray that are split by the splitting unit and have gone through the diffraction unit from the first reflection part to the second reflection part, and reflects the first light ray and the second light ray that are reflected by the fold-back reflection unit from the second reflection part to the first reflection part.

Abstract: The present invention provides an optical angle sensor capable of detecting a wide range of angles with high resolution, having no scale, and specifying a reference angle. The optical angle sensor includes a light source for irradiating light, a reflection means for rotating around a predetermined axis as a measurement axis and reflecting the light irradiated from the light source, a light receiving means for receiving the light irradiated from the light source, and a calculation means for calculating the light received by the light receiving means as a signal. The light receiving means receives the light irradiated from the light source through the reflection means. The calculation means includes a specifying means for specifying the reference angle based on the light received by the light receiving means, and an angle calculating unit for calculating an absolute angle based on the light received by the light receiving means and the reference angle specified by the specifying means.

Abstract: The optical angle sensor comprises a diffraction unit, a light source, a light receiving unit, and a plurality of reflection units. The diffraction unit includes a first diffraction part for generating combined light and a second diffraction part for diffracting a first light and a second light a plurality of times. The plurality of reflection units includes a first reflection unit, a second reflection unit, a third reflection unit that reflects the first light and the second light through the second diffraction part toward the second diffraction part, fourth reflection unit, and fifth reflection unit. The calculating unit, with the rotation of the diffraction unit, calculates the amount of change in the angle based on the change in the interference signal caused by the combined light generated on the light receiving surface.

Abstract: The optical encoder includes a scale, a head moves relative to the scale, and a calculating unit performs calculation based on the relative movement. The head includes a light source and a receiving unit having a light receiving surface. The scale includes a step portion on a scale surface. The step portion generates interference light having a contrast pattern on the light receiving surface, and generate the darkest portion with the highest contrast in the contrast pattern. The light source irradiates the step portion with light in a direction inclined with respect to a direction perpendicular to the scale surface. The calculating unit includes an origin calculating unit that identifies the darkest portion from the contrast pattern and calculates the identified darkest portion as the origin position that is a reference of the relative movement between the scale and the head.

Abstract: An optical encoder 10 comprising: a light source 11; a splitter 12 splits a light from the light source 11, a light receiving unit 16; a scale 13 is arranged on a light path and movable in a measurement direction, a grating being arranged on a main surface of the scale; and an offset diffraction grating 14 includes a plurality of diffraction gratings arranged in the optical path from the splitter 12 to the light receiving unit 16, the plurality of diffraction gratings diffracting the split lights with different phases, wherein, the plurality of diffraction gratings 13 in the offset diffraction grating 14 are arranged in one plane parallel to the main surface of the scale and are offset each other in an offset direction orthogonal to the measurement direction, the light receiving unit 16 includes a plurality of light-receiving elements 16-11 to 16-23 arranged in the offset direction.

Abstract: An optical encoder includes a light source, a plurality of diffraction gratings including grating faces on which a plurality of grooves are disposed in parallel, and a light-receiving unit configured to receive the light diffracted at the plurality of diffraction gratings. The diffraction gratings include a first diffraction grating that is a first-stage diffraction grating adjacent to the light source, a third diffraction grating that is a last-stage diffraction grating adjacent to the light-receiving unit, and a second diffraction grating that is an output-stage diffraction grating of the first-stage diffraction grating and an input-stage diffraction grating of the last-stage diffraction grating. The diffraction gratings are disposed such that the ratio of the first gap to the third gap equals the ratio of the second gap to the fourth gap, and a length of the first gap differs from a length of the second gap.

Abstract: An optical sensor in which an optical component more inexpensive than a corner cube is used as a measurement target and which has accuracy similar to that of a case where the corner cube is used is provided. An optical sensor 1 includes a light source 2, a dividing unit 6, a retroreflection unit 4 that retroreflects first light and second light divided by the dividing unit 6, a combining unit 7, a light receiving unit 5, and a calculation unit 8.

Abstract: An optical encoder includes a scale including a diffraction grating, a light-receiving unit configured to receive light from a light source, and an optical element located between the scale and the light-receiving unit. The optical element includes a plurality of groove portions, which are a periodic structure portion formed periodically in one face of the optical element. The plurality of groove portions is configured to divide signal diffracted light and noise diffracted light into first splitted beams traveling at a predetermined travel angle and second splitted beams traveling at a travel angle greater than the travel angle of the first splitted beams, and make a diffraction efficiency of the first splitted beams of the noise diffracted light lower than a diffraction efficiency of the first splitted beams of the signal diffracted light.

Abstract: The present invention provides an optical angle sensor capable of detecting a wide range of angles with high resolution, having no scale, and specifying a reference angle. The optical angle sensor includes a light source for irradiating light, a reflection means for rotating around a predetermined axis as a measurement axis and reflecting the light irradiated from the light source, a light receiving means for receiving the light irradiated from the light source, and a calculation means for calculating the light received by the light receiving means as a signal. The light receiving means receives the light irradiated from the light source through the reflection means. The calculation means includes a specifying means for specifying the reference angle based on the light received by the light receiving means, and an angle calculating unit for calculating an absolute angle based on the light received by the light receiving means and the reference angle specified by the specifying means.

Abstract: An optical encoder configuration comprises a scale, an illumination source, and a photodetector configuration. The illumination source is configured to output structured illumination to the scale. The scale extends along a measuring axis direction and is configured to output scale light that forms a detector fringe pattern comprising periodic high and low intensity bands that extend over a relatively longer dimension along the measuring axis direction and are relatively narrow and periodic along a detected fringe motion direction transverse to the measuring axis direction. The high and low intensity bands move along the detected fringe motion direction transverse to the measuring axis direction as the scale grating displaces along the measuring axis direction.

Abstract: An optical encoder configuration comprises a scale, an illumination source, and a photodetector configuration. The illumination source is configured to output structured illumination to the scale. The scale extends along a measuring axis direction and is configured to output scale light that forms a detector fringe pattern comprising periodic high and low intensity bands that extend over a relatively longer dimension along the measuring axis direction and are relatively narrow and periodic along a detected fringe motion direction transverse to the measuring axis direction. The high and low intensity bands move along the detected fringe motion direction transverse to the measuring axis direction as the scale grating displaces along the measuring axis direction.

Abstract: An optical encoder configuration comprises a scale, an illumination source, and a photodetector configuration. The illumination source is configured to output structured illumination to the scale. The scale extends along a measuring axis direction and is configured to output scale light that forms a detector fringe pattern comprising periodic high and low intensity bands that extend over a relatively longer dimension along the measuring axis direction and are relatively narrow and periodic along a detected fringe motion direction transverse to the measuring axis direction. The high and low intensity bands move along the detected fringe motion direction transverse to the measuring axis direction as the scale grating displaces along the measuring axis direction.

Abstract: An optical encoder includes a light source, a plurality of diffraction gratings including grating faces on which a plurality of grooves are disposed in parallel, and a light-receiving unit configured to receive the light diffracted at the plurality of diffraction gratings. The diffraction gratings include a first diffraction grating that is a first-stage diffraction grating adjacent to the light source, a third diffraction grating that is a last-stage diffraction grating adjacent to the light-receiving unit, and a second diffraction grating that is an output-stage diffraction grating of the first-stage diffraction grating and an input-stage diffraction grating of the last-stage diffraction grating. The diffraction gratings are disposed such that the ratio of the first gap to the third gap equals the ratio of the second gap to the fourth gap, and a length of the first gap differs from a length of the second gap.