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: A method and an inspection system that exhibiting speckle reduction characteristics includes a light source arranged to generate input light pulses, and diffuser-free speckle reduction optics that include a beam splitter, for splitting an input light pulse from the light source into multiple light pulses that are oriented at angles in relation to each other when exiting the beam splitter, and at least one optical element for directing the multiple light pulses to impinge on an inspected object at different angles.

Abstract: An optical encoder includes a scale having diffraction gratings formed at predetermined pitches in a measurement axis direction, a detection head relatively movable with respect to the scale, the detection head including a light source portion configured to irradiate the scale with light, and a plurality of receiver portions configured to receive light reflected by or transmitted through the diffraction gratings of the scale, at different phases, and a signal processing device configured to perform signal processing to light reception signals output from the receiver portions of the detection head, to produce quadrature differential signals. The signal processing device is configured to calculate alignment adjustment monitor signals corresponding to a Lissajous radius of the quadrature differential signals in order to detect misalignment of the detection head with respect to the scale.

Abstract: In an optical position-measuring device for recording the relative position of a scanning unit and a measuring standard, the scanning unit includes a light source, first annular scanning graduation, reflector element, beamsplitter element, and detection unit. A beam emitted by the light source impinges on the measuring graduation and is split into at least two partial beams of rays. The partial beams propagate toward the scanning unit, impinge the first scanning graduation on the reflector element, are reflected through the first scanning graduation toward the measuring graduation, impinge the measuring graduation, propagate toward the scanning unit and undergo superposition, and are deflected by the beamsplitter element toward the detection unit. There, a plurality of positionally dependent, phase-shifted scanning signals can be recorded.

Abstract: A detection head includes a plurality of detection array portions that are arranged in a direction along which the head is relatively displaceable. Position signals indicating a position of the detection head are calculated from output signals output from the detection array portions. In order to combine the position signals with one another and determine the position of the detection head with respect to the scale, weighting according to a level of the output signal is performed on the position signal of each of the detection array portions, and the weighted position signals are averaged.

Abstract: A projection display device having a projection device projecting an image on a surface, and a position detection function of detecting an object's position between the surface and the projection device, includes: a light source emitting light beams toward the object; a light detector detecting the light beams reflected by the object; and a position detector detecting the object's position in an imaginary plane based on the light detector's result, wherein the light source emits, as the light beams, first through third light beams having first through third intensity distributions, the second intensity distribution having a highest intensity at a position failing to overlap a highest intensity of the first intensity distribution, and the third intensity distribution having a highest intensity portion at a position failing to overlap a straight line connecting the highest intensity portions of the first and second intensity distributions.

Abstract: An optical encoder includes a light-emitting unit, a scale with a discontinuous part, and a plurality of light-receiving elements arranged in relationship to a pitch of the scale. In the optical encoder, a light beam from the light-emitting unit reflects off the scale, and is received at the light-receiving elements. As a result of the processing of signals from the light-receiving elements, the discontinuous part is detected and the origin detection can be achieved.

Abstract: An optical displacement-measuring instrument of a reflection type includes a sensor head movable above a scale in a direction of measurement. This instrument is of a three-grating type that comprises a first optical grating arranged close to a light source, a second optical grating arranged on the scale, and a third optical grating arranged in a photoreceptor. A light diffuser is arranged between the light source and the first optical grating. A collimated light from the light source is diffused at the light diffuser and led to the first optical grating.

Abstract: A non-contact three-dimensional surface measurement method is provided in which a grating pattern projected onto an object being measured, while the phase of the pattern is being shifted, is observed in a different direction from a projection direction to analyze the contrast of a grating image deformed in accordance with the shape of the object and thereby obtain the shape thereof. The method enables measurement of a three-dimensional shape over a large measurement range in a short time in a non-contact manner by successively shifting the focus on the projection and the imaging sides to enlarge the measurement range in the direction of depth.

Abstract: A scanning unit for an optical position measuring device, the scanning unit having a structured optoelectronic photodetector that includes: a semiconductor substrate, a plurality of radiation-sensitive detector areas, which are arranged next to each other on the semiconductor substrate and a strip conductor, wherein at least a portion of the strip conductor is positioned across a surface defined by the plurality of detector areas and forms a connection with an associated detector area of the plurality of detector areas.

Abstract: A measurement signal generating circuit for a linear scale capable of increasing an Signal-to-Noise (S/N) ratio, wherein S stands for Corona signal strength, and N for noise strength ratio of a signal for measurement of a linear scale. A photo detector or a low-pass filter for removing noise entering the measurement signal generating circuit is arranged rearwardly of each of an A phase signal generating circuit and a B phase signal generating circuit. Such construction permits a noise component at a different phase as well as that at the same phase to be effectively removed during synthesis of the measurement signal, to thereby reduce an error in measuring by the linear scale.

Abstract: An electronic circuit for measuring the position of a spatially periodic intensity pattern of incident radiation includes an array of detectors (1); two or more correlator units (2, 3) each having arrays of capacitors (12, 13) connected to a buffer (14); and a phase angle computing unit (4). The pitch of the array of detectors (1) is smaller than the pitch of the incident intensity pattern so that the latter is oversampled, yielding high accuracy. The detector outputs (17) are weighted by respective fixed capacitance values (15, 16) which vary periodically along arrays of capacitors (12, 13), and a weighted sum of outputs for each correlator unit (2, 3) is output at its respective buffer (14). The capacitance values (15, 16) of respective correlator units (2, 3) are mutually offset by a predetermined phase shift. The analog computation using capacitor arrays (12, 13) is fast and energy efficient, and can be implemented as a VLSI circuit.

Abstract: A position measuring system that includes a scale having an incremental track, which extends in a measuring direction and has an incremental graduation with two different graduation periods. A scanning unit moves in relation to the scale in a measuring direction, the scanning unit has an incremental signal detection arrangement, wherein the incremental signal detection arrangement generates incremental signals with a first coarse signal period and generates incremental signals with a second finer signal period.

Abstract: In a moire apparatus having a projection grating 40, three-dimensional data of an object to be measured 2 is computed from the moire fringe observed while the projection grating 40 is moved, a distance-measuring reference point P (X, Y, Z) on the object 2 is selected from the three-dimensional data, and the distance L between the distance-measuring reference point P (X, Y, Z) and a taking lens 44 is measured. The distance L can automatically be measured by detecting the peak of video output signal of a CCD camera 52 while moving its lens 52L along the optical axis. Also, the distance-measuring reference point P (X, Y, Z) may be displayed with a flag on a monitor 18 for observing the moire fringe, and the distance between the object 2 and the taking lens 44 may be measured with reference to the flag-displayed pixel. A stationary grating 102 having a pitch identical to that of the projection grating 40 is disposed near the projection grating 40, so as to form a moire fringe.