Abstract: A miniaturized optical encoder capable of obtaining a sufficient amount of light in the light receiving element is provided. An optical encoder 1 includes a scale 2 having scale markings 21 and a readhead 3 having a light source 31 that emits light to the scale 2, a scale-side lens 32 that transmits the light emitted from the light source 31 to the scale 2, and a light receiving element 33 that receives the light that has been reflected by the scale 2 and that has passed through the scale-side lens 32. The light source 31 is arranged between the scale-side lens 32 and the light receiving element 33, and a distance between the light source 31 and the scale-side lens 32 is set to be a focal distance fs of the scale-side lens 32.

Abstract: A miniaturized optical encoder capable of obtaining a sufficient amount of light in the light receiving element is provided. An optical encoder 1 includes a scale 2 having a scale track 2? and a readhead 3 having a light source 31 that emits light to the scale track 2?, a scale-side lens 32 that transmits the light emitted from the light source 31 to the scale track 2?, and a light receiving element 33 that receives the light reflected by the scale track 2? through the scale-side lens 32. The light source 31 is arranged between the scale-side lens 32 and the light receiving element 33. An optical axis Lsrc of the light source 31 is matched with an optical axis Ls of the scale-side lens 32 in a reading direction of the scale 2 and is separated from an optical axis Ls of the scale-side lens 32 by a predetermined distance D in a direction perpendicular to the reading direction of the scale 2.

Abstract: A method and apparatus for suppressing loss of scale image contrast due to interference effects from optical path length differences, including lens profile aberrations, are provided in a displacement sensing optical encoder that uses a telecentric imaging configuration. According to the invention, the encoder is configured such that the image light that reaches the detector comprises symmetric ray bundles concentrated symmetrically on opposite sides of the optical axis center at the limiting aperture of the telecentric imaging configuration. Central ray bundles, and/or other ray bundles that have an optical path lengths significantly different than the operational symmetric ray bundles are prevented or blocked. As a result destructive interference is prevented and image contrast is improved.

Abstract: A reflection type encoder, which receives a plurality of light-receiving signals from a single scale, includes a light source, a scale having a plurality of patterns formed thereon to which light is irradiated from the light source, and a light-receiving element for receiving light reflected from each of the plurality of patterns, wherein a plurality of patterns each having different thicknesses are formed on a single track of the scale by using a dielectric substance, light of a plurality of wavelengths each having different brightnesses in accordance with differences in the thickness of the dielectric substance is irradiated from the light source, and a light-receiving signal is obtained for the respective thicknesses of the dielectric substance. Therefore, the scale can be downsized by overlapping a plurality of patterns on the same track.

Abstract: A photoelectric encoder includes: a scale having a grating formed thereon along a measuring axis; a light source operative to emit light to the scale so as to form a light spot on the grating; and a photoreceiver operative to receive reflected light from the scale. The light source and the photoreceiver are disposed so as to be allowed to move relative to the scale at least in a direction along the measuring axis. The light source emits the light to the scale so that the photoreceiver receives the reflected light by the scale. The light source emits light with different wavelengths. The scale includes a plurality of reflection portions that respectively reflect the light with different wavelengths.

Abstract: An optical encoder (100) is provided with: a light-emitting element (30) including a main-signal light-emitting element (31) having a red LED (31A) that emits red light and an origin light-emitting element (32) having an infrared LED (32A) that emits infrared light; and a receiver unit (40) including a main-signal photo detector (41) that receives the red light to generate a predetermined signal and an origin photo detector (42) that receives the infrared light to generate a predetermined signal. Accordingly, even when the infrared light enters the main-signal photo detector (41) or the red light enters the origin photo detector (42), no signal is generated by the light, thereby effectively preventing crosstalk. Thus, the measurement accuracy of the optical encoder (100) can be improved.

Abstract: A reflection type encoder includes a reflection scale 20 having an origin pattern formed thereon, a light source 42 for irradiating light to the origin pattern, and a light receiving element 50 for detecting reflection light from the origin pattern, in which the origin pattern on the reflection scale 20 is detected by the reflection light, and further includes an incoming side origin pattern 26 and an outgoing side origin pattern 28, which are formed on the reflection scale 20, a reflection slit 46 disposed at the same side as the light source 42 and the light receiving element 50 with respect to the reflection scale 20, an incoming side lens 44 that composes an incoming side telecentric optical system in which the incoming side origin pattern 26 is made to be the object plane, and an outgoing side lens 48 that composes the outgoing side telecentric optical system in which the outgoing side origin pattern 28 is made to be the image forming plane, wherein a telecentric optical system is composed of the incomin

Abstract: A three-grating type photoelectric encoder includes a second grating formed on a scale and first and third gratings disposed on a side of a detector. A part of at least the first grating is shifted in a direction of a measurement axis by P/(2n) (wherein P is a grating pitch, n is the order of a harmonic component to be removed) in order to remove a harmonic component of the nth order. This encoder can be improved with high accuracy by removing harmonic components without increasing manufacturing costs.

Abstract: In a photoelectric encoder (incremental encoder and absolute encoder) having a detector that is displaceable relative to a scale having a predetermined pattern (incremental pattern and pseudorandom pattern) formed thereon, the detection range, to be simultaneously detected, of the pattern is divided in at least the detection direction, and a plurality of light-receiving systems are provided to detect each of the respective detection areas, whereby measurement of a wide detection range is enabled by using a small-sized and simple optical system and light-receiving system.

Abstract: An optical encoder (100) is provided with: a light-emitting element (30) including a main-signal light-emitting element (31) having a red LED (31A) that emits red light and an origin light-emitting element (32) having an infrared LED (32A) that emits infrared light; and a receiver unit (40) including a main-signal photo detector (41) that receives the red light to generate a predetermined signal and an origin photo detector (42) that receives the infrared light to generate a predetermined signal. Accordingly, even when the infrared light enters the main-signal photo detector (41) or the red light enters the origin photo detector (42), no signal is generated by the light, thereby effectively preventing crosstalk. Thus, the measurement accuracy of the optical encoder (100) can be improved.

Abstract: A photoelectric encoder includes: a scale having a grating formed thereon along a measuring axis; a light source operative to emit light to the scale so as to form a light spot on the grating; and a photoreceiver operative to receive reflected light from the scale. The light source and the photoreceiver are disposed so as to be allowed to move relative to the scale at least in a direction along the measuring axis. The light source emits the light to the scale so that the photoreceiver receives the reflected light by the scale. The light source emits light with different wavelengths. The scale includes a plurality of reflection portions that respectively reflect the light with different wavelengths.

Abstract: A photoelectric encoder is provided, which emits light from a light source to a main scale and an index scale that can relatively move with respect to each other and obtains a light-receiving signal by interaction between the main scale and the index scale. The photoelectric encoder uses as the light source an incoherent semiconductor light source (white LED) in which a full width at half maximum of an emission spectrum is wider than that of a monochromatic semiconductor light source. Thus, it is possible to reduce an effect of a gap change on an output signal of the encoder and make positional adjustment easier, thereby improving misalignment characteristics.

Abstract: In a photoelectric encoder (incremental encoder and absolute encoder) having a detector that is displaceable relative to a scale having a predetermined pattern (incremental pattern and pseudorandom pattern) formed thereon, the detection range, to be simultaneously detected, of the pattern is divided in at least the detection direction, and a plurality of light-receiving systems are provided to detect each of the respective detection areas, whereby measurement of a wide detection range is enabled by using a small-sized and simple optical system and light-receiving system.

Abstract: A three-grating type photoelectric encoder includes a second grating formed on a scale and first and third gratings disposed on a side of a detector. A part of at least the first grating is shifted in a direction of a measurement axis by P/(2n) (wherein P is a grating pitch, n is the order of a harmonic component to be removed) in order to remove a harmonic component of the nth order. This encoder can be improved with high accuracy by removing harmonic components without increasing manufacturing costs.

Abstract: A photoelectric encoder is provided, which emits light from a light source to a main scale and an index scale that can relatively move with respect to each other and obtains a light-receiving signal by interaction between the main scale and the index scale. The photoelectric encoder uses as the light source an incoherent semiconductor light source (white LED) in which a full width at half maximum of an emission spectrum is wider than that of a monochromatic semiconductor light source. Thus, it is possible to reduce an effect of a gap change on an output signal of the encoder and make positional adjustment easier, thereby improving misalignment characteristics.

Abstract: An optical encoder comprises a main scale (1) having scale gratings (11) formed thereon with a certain angular pitch along a measurement axis (x1) that describes a circular arc. It also comprises a detection bead (2) having photoreceptive optical gratings (7) formed thereon. The detection head is arranged relatively movable along the measurement axis (x1), opposing to the main scale (1). The photoreceptive optical gratings (7) on the detection head (2) have transparent and opaque portions alternately arranged with a certain distance pitch along a straight, grating arrangement axis (x2).

Abstract: An optical encoder is constructed by a reflection-type scale 1 and a sensor head 4. The sensor head 4 has an irradiation light source 2 and a sensor board 3, the sensor board 3 has a transparent substrate 30 on which light-receiving areas 5 for outputting displacement signals which have different phase with each other, and index gratings 6 for modulating the scale irradiating light are formed to be alternately arranged. The index gratings 6 are formed of the same material film as metal electrode of the light-receiving areas 5.

Abstract: An optical encoder is constructed by a reflection-type scale 1 and a sensor head 4. The sensor head 4 has an irradiation light source 2 and a sensor board 3. the sensor board 3 has a transparent substrate 30 on which light-receiving areas 5 for outputting displacement signals which have different phase with each other, and index gratings 6 for modulating the scale irradiating light are formed to be alternately arranged. The index gratings 6 are formed of the same material film as metal electrode of the light-receiving areas 5.

Abstract: A capacitance-type measuring device for absolute measurement of positions is disclosed, which comprises a displacement sensor having a fixed element and a movable element, the movable element being capacitance-coupled to the fixed element and relatively movable against the fixed element, the displacement sensor being adapted to output signals corresponding to relative positions of the movable element against the fixed element, a signal processing circuit for processing the output signals of the displacement sensor and outputting an absolute measurement value corresponding to displacement of the movable element against the fixed element, a control circuit for controlling the operations of the displacement sensor and the signal processing circuit, and a power supply for supplying electric power to the displacement sensor, the signal processing circuit, and the control circuit, wherein the control circuit activates the signal processing circuit at a suitable interval so as to perform an intermittent measurement