公开(公告)号：US10591321B2

公开(公告)日：2020-03-17

申请号：US15920364

申请日：2018-03-13

Applicant: Mitutoyo Corporation

Inventor： Akihide Kimura

IPC: G01D5/347 ,  G02B27/10

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.

公开(公告)号：US10295378B2

公开(公告)日：2019-05-21

申请号：US15702520

申请日：2017-09-12

Applicant: Mitutoyo Corporation

Inventor： Joseph Daniel Tobiason ,  Norman Laman ,  Akihide Kimura ,  Shu Hirata

IPC: G01D5/347 ,  G01D5/244

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. The photodetector configuration is configured to detect a displacement of the high and low intensity bands along the detected fringe motion direction and provide respective spatial phase displacement signals that are indicative of the scale displacement.

公开(公告)号：US10274344B2

公开(公告)日：2019-04-30

申请号：US16012064

申请日：2018-06-19

Applicant: MITUTOYO CORPORATION

Inventor： Akihide Kimura ,  Joseph Daniel Tobiason

IPC: G01D5/34 ,  G01D5/347 ,  G01D5/38

Abstract: A detection head movable relative to a scale detects diffracted light and outputs a detection result. The diffracted light is diffracted by an incremental pattern. A signal processing unit calculates a relative displacement between the scale and the detection head. The detection head includes: a light source emitting the light to the scale; and a detection unit including a light-receiving unit receiving the diffracted light through an optical element, in which the light-receiving elements outputting detection signals are periodically arranged with a predetermined period. The number of the plurality of light-receiving elements is an even number. The predetermined period is a value obtained by multiplying a fundamental period by an odd-number. The fundamental period is a period of interference fringes formed on the light-receiving unit by +1st and −1st order diffracted lights. A width of the light-receiving element is not equal to an integral multiple of the fundamental period.

公开(公告)号：US10190892B2

公开(公告)日：2019-01-29

申请号：US15384613

申请日：2016-12-20

Applicant: MITUTOYO CORPORATION

Inventor： Akihide Kimura

IPC: G01D5/347

Abstract: A scale is provided with a reference mark and an incremental pattern. A detection head is relatively movable in a measurement direction with respect to the scale, and detects a light intensity distribution of diffracted beams if beams radiated onto the scale are diffracted by the reference mark, and outputs the detection result. A signal processing unit detects a reference position based on a position in the light intensity distribution where light intensity is lower than a predetermined value. The reference position has a plurality of pattern areas having a plurality of patterns arranged with a predetermined pitch in the measurement direction. At least one pattern area of the plurality of pattern areas is disposed with an offset from a neighboring pattern area in the measurement direction.

公开(公告)号：US09903742B2

公开(公告)日：2018-02-27

申请号：US15220487

申请日：2016-07-27

Applicant: MITUTOYO CORPORATION

Inventor： Akihide Kimura

IPC: G01D5/34 ,  G01D5/26 ,  G01D5/38

CPC classification number: G01D5/266 ,  G01D5/38

Abstract: A displacement detecting device includes a main scale and a detecting head unit. The detecting head unit includes a light source, a light receiving unit, and an index scale group that is disposed in the middle of a light path from the main scale to the light receiving unit. The index scale group includes two or more index scales including diffraction gratings, respectively. A positive s-th order diffracted light and a negative s-th order diffracted light of diffracted lights from the main scale are used as the signal lights. The displacement detecting device satisfies a first condition and a second condition, the first condition being expressed as follows: λ×(u1−u2)×(mN÷g)=2×sin α, the second condition being expressed as follows: λ×u1×(mN÷g)−sin α≠λ÷g×Σi=1N (ti×mi).

公开(公告)号：US09534936B2

公开(公告)日：2017-01-03

申请号：US14270778

申请日：2014-05-06

Applicant: MITUTOYO CORPORATION

Inventor： Akihide Kimura

IPC: G01D5/347 ,  G01D5/244 ,  G01D5/36 ,  G01D5/38

CPC classification number: G01D5/34715 ,  G01D5/24438 ,  G01D5/366 ,  G01D5/38

Abstract: A reference signal generation circuit generates a reference signal from a reading result of the reference point detection pattern. The first light-receiving element array includes a first light-receiving element that outputs a first signal, and a second light-receiving element that is disposed in a first direction of the first light-receiving element and outputs a second signal. A second light-receiving element array includes a third light-receiving element that outputs a third signal, and a fourth light-receiving element that is disposed in the first direction of the third light-receiving element and outputs a fourth signal. The second light-receiving element array is disposed in a second direction of the first light-receiving element array. The reference signal generation circuit outputs a reference signal that starts at a period when levels of the first and second signal become equal and ends at a period when levels of the third and fourth signal become equal.

Abstract translation: 参考信号产生电路根据参考点检测图案的读取结果产生参考信号。 第一光接收元件阵列包括输出第一信号的第一光接收元件和设置在第一光接收元件的第一方向上并输出第二信号的第二光接收元件。 第二光接收元件阵列包括输出第三信号的第三光接收元件和设置在第三光接收元件的第一方向上并输出第四信号的第四光接收元件。 第二光接收元件阵列设置在第一光接收元件阵列的第二方向上。 参考信号产生电路输出在第一和第二信号的电平变为相等的时段开始的参考信号，并且在第三和第四信号的电平相等时的周期结束。

公开(公告)号：US09134144B2

公开(公告)日：2015-09-15

申请号：US13659213

申请日：2012-10-24

Applicant: MITUTOYO CORPORATION

Inventor： Akihide Kimura

IPC: G01D5/34 ,  G01D5/244

CPC classification number: G01D5/24495 ,  G01D5/24452

Abstract: A displacement detecting device includes: a scale which has an optical lattice; a detecting unit which is disposed so as to be movable in a scanning direction relative to the scale, inclusive of at least a first detection portion, a second detection portion and a third detection portion, arranged in the scanning direction for detecting position information from the optical lattice; and a calculating portion configured to obtain a self-calibration curve on graduations of the scale by specifying positions of the detection portions and calculating measurement error based on the position information detected by the detecting unit, wherein: the detecting unit is provided so that a distance between the first detection portion and the second detection portion and a distance between the second detection portion and the third detection portion are different from each other and do not form an integral multiple.

Abstract translation: 位移检测装置包括：具有光栅的标尺; 检测单元，其设置成能够相对于标尺在扫描方向上移动，包括至少第一检测部分，第二检测部分和第三检测部分，其布置在扫描方向上，用于检测来自 光栅; 以及计算部，被配置为通过指定所述检测部的位置来获得所述刻度的刻度上的自校正曲线，并且基于由所述检测单元检测的位置信息来计算测量误差，其中：所述检测单元被设置成使得所述检测单元的距离 在第一检测部分和第二检测部分之间以及第二检测部分和第三检测部分之间的距离彼此不同，并且不形成整数倍。

公开(公告)号：US20130099106A1

公开(公告)日：2013-04-25

申请号：US13659213

申请日：2012-10-24

Applicant: MITUTOYO CORPORATION

Inventor： Akihide Kimura

IPC: G01D5/347

CPC classification number: G01D5/24495 ,  G01D5/24452

Abstract: A displacement detecting device includes: a scale which has an optical lattice; a detecting unit which is disposed so as to be movable in a scanning direction relative to the scale, inclusive of at least a first detection portion, a second detection portion and a third detection portion, arranged in the scanning direction for detecting position information from the optical lattice; and a calculating portion configured to obtain a self-calibration curve on graduations of the scale by specifying positions of the detection portions and calculating measurement error based on the position information detected by the detecting unit, wherein: the detecting unit is provided so that a distance between the first detection portion and the second detection portion and a distance between the second detection portion and the third detection portion are different from each other and do not form an integral multiple.

Abstract translation: 位移检测装置包括：具有光栅的标尺; 检测单元，其设置成能够相对于标尺在扫描方向上移动，包括至少第一检测部分，第二检测部分和第三检测部分，其布置在扫描方向上，用于检测来自 光栅; 以及计算部，被配置为通过指定所述检测部的位置来获得所述刻度的刻度上的自校正曲线，并且基于由所述检测单元检测的位置信息来计算测量误差，其中：所述检测单元被设置成使得所述检测单元的距离 在第一检测部分和第二检测部分之间以及第二检测部分和第三检测部分之间的距离彼此不同，并且不形成整数倍。

公开(公告)号：US20230059800A1

公开(公告)日：2023-02-23

申请号：US17407761

申请日：2021-08-20

Applicant: Mitutoyo Corporation

Inventor： Norman Laman ,  Joseph Daniel Tobiason ,  Shu Hirata ,  Tatsuhiko Mukuta ,  Akihide Kimura

IPC: G01D5/347

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. The plurality of element arrays 71-74 in the element array group 7 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 71, 72; and (ii) a distance in the orthogonal direction from the reference position to the negative phase signal element array 73, 74, is the same for all the phases of the at least two phases.

公开(公告)号：US10746573B2

公开(公告)日：2020-08-18

申请号：US16175053

申请日：2018-10-30

Applicant: Mitutoyo Corporation

Inventor： Akihide Kimura

IPC: G01D5/26 ,  G01D5/38 ,  G01D5/347 ,  G02B27/60

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.