公开(公告)号：US09851224B2

公开(公告)日：2017-12-26

申请号：US14990937

申请日：2016-01-08

Applicant: MITUTOYO CORPORATION

Inventor： Satoshi Adachi ,  Youhei Toku ,  Toshihiro Hasegawa

IPC: G01D5/24 ,  G01D5/244 ,  G01D5/241

CPC classification number: G01D5/24419 ,  G01D5/2415

Abstract: A phase detector includes a sampling signal generator configured to generate a sampling signal at an edge of a scale signal, a counter configured to count up a count value according to a clock pulse every certain time and to output the count value at a timing instructed by the sampling signal, an edge polarity determinator configured to determine whether an edge polarity of the scale signal is a rising edge or a falling edge and to generate an adjustment signal when the polarity of the edge where the sampling signal is generated is a falling edge and an adjuster configured to add a predetermined adjustment amount to the count value output from the counter when receiving the adjustment signal.

公开(公告)号：US11340095B2

公开(公告)日：2022-05-24

申请号：US17077313

申请日：2020-10-22

Applicant: Mitutoyo Corporation

Inventor： Osamu Kawatoko ,  Toshihiro Hasegawa ,  Tomohiro Tahara ,  Akio Kawai

IPC: G01D5/20 ,  G01B7/00 ,  G01B3/20

Abstract: An object is to respectively excite transmission coils with different voltages using a single power supply with low power consumption in an electromagnetic induction type encoder. A detection head of an encoder includes a voltage adjustment circuit and a plurality of excitation circuits. The excitation circuit includes a resonant circuit that includes a driving capacitor and a transmission coil connected in series and generates an alternate-current magnetic field inducing currents in scale coils disposed in a plurality of scale tracks on a scale by connecting both ends of the resonant circuit in a state in which the driving capacitor is charged. The voltage adjustment circuit includes a first transformer capacitor and controls a charging voltage of the driving capacitor in a single excitation circuit using the charged first transformer capacitor.

公开(公告)号：US20210131831A1

公开(公告)日：2021-05-06

申请号：US17077313

申请日：2020-10-22

Applicant: Mitutoyo Corporation

Inventor： Osamu Kawatoko ,  Toshihiro Hasegawa ,  Tomohiro Tahara ,  Akio Kawai

IPC: G01D5/20 ,  G01B7/00 ,  G01B3/20

Abstract: An object is to respectively excite transmission coils with different voltages using a single power supply with low power consumption in an electromagnetic induction type encoder.
A detection head of an encoder includes a voltage adjustment circuit and a plurality of excitation circuits. The excitation circuit includes a resonant circuit that includes a driving capacitor and a transmission coil connected in series and generates an alternate-current magnetic field inducing currents in scale coils disposed in a plurality of scale tracks on a scale by connecting both ends of the resonant circuit in a state in which the driving capacitor is charged. The voltage adjustment circuit includes a first transformer capacitor and controls a charging voltage of the driving capacitor in a single excitation circuit using the charged first transformer capacitor.