Dmg Mori Company Limited

Mori Seiki Co., Ltd.

Dmg Mori Seiki Co., Ltd.

Masayuki Niiya

Hideaki Tamiya

Kayoko Taniguchi

Kenji Matsushita

Akinori Suzuki

Terukazu Nishida

A displacement detection device is capable of stably and accurately detecting an amount of displacement. A polarization maintaining fiber has a length not to be equal to a length obtained by dividing, a product of an integral multiple of twice a length of a resonator times a refractive index of the resonator and a beat length obtained from a difference between propagation constants of two polarization modes, by a wavelength of the light source, is selected from a range including a length equal to the above length. The polarization maintaining fiber includes multiple polarization maintaining fibers fitted to each other by removable connectors.

Displacement detection device

In order to provide a detection device that can accurately detect thermal deformation in any state including a case where thermal deformation has already occurred, there is provided a detection device which includes: a scale with a strained grating; and two sensor heads mounted on a pedestal at a predetermined distance, the sensor heads detecting positions on the scale based on the grating. Thermal deformation of the pedestal or the scale is detected based on a change in a difference between the positions detected by the two sensor heads.

Detection device

In order to provide a small detection device capable of detecting an accurate absolute position with a single head, there is provided a detection device including a head including a light source and a detecting unit configured to receive multiplexed light (interference light) of diffracted light obtained by causing light from the light source to enter first two points residing on ax diffraction grating and being separated from each other by a known distance and diffracted light obtained by causing the light from the light source to enter second two points residing on the diffraction grating, being separated from each other by a known distance, and including at least one point being different from the first two points, wherein the diffraction grating includes a first region between the first two points separated from each other by the known distance and a second region between the second two points separated from each other by the known distance, the first and second regions having at least partially different grating interval lengths, and an absolute position on the diffraction grating is detected based on the multiplexed light (interference light) received by the detecting unit.

Disclosed embodiments include a two-dimensional scale with a simple arrangement capable of omitting setting of an origin mark in the Y-axis direction. In a linear scale, a reference origin mark array and a tilting origin mark array that is a tilting marker array are provided in an origin mark region. Since the reference origin mark array is parallel to X-coordinates, an X-direction origin signal is correctly generated. On the other hand, for the Y direction in which no origin mark is provided, the distance between a reference origin mark and a tilting origin mark is detected. A Y-direction absolute position is decided in accordance with the distance.

Scale device and two-axis displacement detection device

A displacement detection apparatus capable of stably and accurately detecting the amount of displacement. The length of a polarization maintaining fiber for transmitting the light from a light source to a displacement detector is set not to be equal to a length obtained by dividing, by the wavelength of the light source, a product of an even integral multiple of a length, which is obtained by multiplying twice the length of a resonator by the refractive index of the resonator, and a beat length obtained by a difference between the propagation constants of two polarization modes. Alternatively, the length of the polarization maintaining fiber is set to be larger than a length, which is obtained by dividing, by the wavelength of the light source, a product of a coherence length and a beat length obtained from a difference between the propagation constants of two polarization modes.

Displacement detection apparatus

An optical fiber unit () includes a tube () having stretchability in the axial direction, an optical fiber () movably housed in the tube (), and a linear body () formed of a material having less stretchability than the tube (). Both ends of the linear body () are fixed to both end portions of the tube () in a state where the tube () has been previously shrunk in the axial direction.

Growing community of inventors

Isehara, Japan

Masayuki Niiya