Stanley Electric Co., Ltd

Tokyo University of Science Foundation

Takanori Aimono

Yoshiaki Yasuda

Masanao Tani

Masahiro Akamatsu

Koji Matsumoto

Yuki Yamaguchi

Keiichi Ikegami

Masakazu Satsu

Shinichi Uozumi

Keishi Nishio

Provided is a hydrogen concentration measuring device capable of measuring with high accuracy a hydrogen concentration over an extensive range by a simple configuration. The device includes: a sensor chip which detects the electric resistance of a sensing film; an optical measurement unit which detects the transmitted light intensity of the film; and a controller. The controller performs measurement processing such that a hydrogen concentration in the gas atmosphere is measured based on the detected electric resistance in a first measurement range and based on the detected transmitted light intensity in a second measurement range and is determined so as to reduce a difference between the hydrogen concentration based on the detected electric resistance and the hydrogen concentration based on the detected transmitted light intensity in the overlap of the first measurement range and the second measurement range.

Hydrogen concentration measuring device

In a driver for driving an optical deflector including a mirror, a piezoelectric actuator and a piezoelectric sensor adapted to sense vibrations of the piezoelectric actuator, a saw-tooth voltage generating unit; a combined saw-tooth voltage generating unit; and a control unit, the control unit applies a saw-tooth voltage and its inverted voltage to the piezoelectric actuator; performs a low-pass filtering process using a cut-off frequency upon a sense voltage; calculates a half period of fluctuations included in a low-pass-filtered saw-tooth voltage; combines the low-pass-filtered saw-tooth voltage with a delayed low-pass-filtered saw-tooth voltage; and to applies a combined saw-tooth voltage and its inverted voltage to the piezoelectric actuator.

Driver for optical deflector using combined saw-tooth drive voltage and method for controlling the same

An optical deflector includes a mirror, an inner frame surrounding the mirror, first and second torsion bars coupled between the mirror and the inner frame, first and second inner piezoelectric actuators coupled between the first and second torsion bars supported by first and second inner coupling portions to the inner frame, and an outer frame surrounding the inner frame. The inner frame is supported by first and second outer coupling portions to the outer frame. A circumferential rib is provided on a rear surface of the inner frame. A first branch rib is provided on a rear surface of the first outer coupling portion, and a second branch rib is provided on a rear surface of the second outer coupling portion.

Optical deflector including inner frame with circumferential rib and branch ribs

In an optical deflector including a mirror, a movable frame supporting the mirror, a first piezoelectric actuator for rocking the mirror with respect to a first axis of the mirror, a support body supporting the movable frame, and a second piezoelectric actuator for rocking the mirror through the movable frame with respect to a second axis of the mirror, at least one piezoelectric sensor is provided for sensing rocking vibrations of the mirror caused by the first and second piezoelectric actuators. The second piezoelectric actuator includes a pair of meander-type piezoelectric actuators opposite to each other with respect to the first axis. Each of the second meander-type piezoelectric actuators includes a plurality of piezoelectric cantilevers folded at every cantilever and connected from the support body to the movable frame in parallel with the first axis. The piezoelectric sensor is incorporated into an outermost one of the piezoelectric cantilevers.

Optical deflector including piezoelectric sensor incorporated into outermost piezoelectric cantilever

In an optical deflector including a mirror, a support frame surrounding the mirror, at least one torsion bar arranged along an axis of the mirror having an end coupled to an outer circumference of the mirror, a pair of piezoelectric actuators arranged between the support frame and the torsion bar, and a piezoelectric sensor inserted between the torsion bar and one of the piezoelectric actuators, the piezoelectric sensor includes at least one piezoelectric sensor element having a width being smaller than two-fifths of a width of the one of the piezoelectric actuators and being arranged at a wide portion within two-fifths of the width from an inner end of the one of the piezoelectric actuators.

Optical deflector including narrow piezoelectric sensor element between torsion bar and piezoelectric actuator

An optical deflector is provided which can effectively suppress occurrence of a ringing phenomenon when a piezoelectric actuator is driven with a voltage signal of a sawtooth waveform. An optical deflector Aincludes a control circuitthat detects a mechanical natural frequency relevant to swinging about a second axis Xof a movable part. The control circuitapplies a voltage signal of a sawtooth waveform from which the natural frequency and a harmonic component thereof are removed to outside piezoelectric actuatorsand. The control circuitremoves a frequency component, which is equal to or greater than a second threshold value Gwithin a predetermined frequency range out of frequency components of a voltage signal output from a detecting piezoelectric body, from a drive voltage.

Optical deflector

In an optical deflector including a mirror, a movable frame supporting the mirror, a support body surrounding the movable frame, and a first group of piezoelectric actuators and a second group of piezoelectric actuators alternating with the first group of piezoelectric actuators, a driver combines first and second original saw-tooth waves having the same waveform into first saw-tooth waves, and applies a first drive voltage having the first saw-tooth waves to the first group of piezoelectric actuators. The driver applies a second drive voltage having second saw-tooth waves opposite in phase with the first saw-tooth waves to the second group of piezoelectric actuators.

Driver for optical deflector using two modified syncronous saw-tooth drive voltages and method for setting the same

An optical deflector includes a mirror, a movable frame for supporting the mirror, a support body surrounding the movable frame, and a first group of piezoelectric actuators and a second group of piezoelectric actuators alternating with the first group of piezoelectric actuators. A driver applies a first drive voltage having first saw-tooth waves to the first group of piezoelectric actuators, and applies a second drive voltage having second saw-tooth waves opposite in phase with the first saw-tooth waves to the second group of piezoelectric actuators. A difference in phase between the first and second saw-tooth waves is a predetermined value to suppress resonation of harmonic frequency components of the first and second drive voltages with a natural frequency of a mechanically-vibrating system of the mirror with respect to the axis thereof depending upon the piezoelectric actuators.

Driver for optical deflector using two asyncronous saw-tooth drive voltages and method for setting the same

In a two-dimensional optical deflector including a mirror, a movable frame supporting the mirror, a first piezoelectric actuator connected between the movable frame and the mirror and adapted to rock the mirror with respect to a first axis of the mirror, a support body supporting the movable frame, and a second piezoelectric actuator connected between the support body and the movable frame and adapted to rock the mirror through the movable frame with respect to a second axis of the mirror, at least one piezoelectric sensor is provided on the movable frame and adapted to sense rocking vibrations of the mirror caused by the first and second piezoelectric actuators.

Two-dimensional optical deflector including piezoelectric sensor on movable frame

A driver for driving an optical deflector includes a mirror, a movable frame for supporting the mirror, a support body surrounding the movable frame, and a first group of piezoelectric actuators and a second group of piezoelectric actuators alternating with the first group of piezoelectric actuators. A first drive voltage for the first group of piezoelectric actuators has first repeated waves each with a first rising period. A second drive voltage for the second group of piezoelectric actuators has second repeated waves each with a second falling period corresponding to the first rising period of the first drive voltage and a second rising period corresponding to the first falling period of the first drive voltage. Frequencies of the first and second repeated waves exclude natural frequencies of a mechanically-vibrating system of the mirror with respect to the axis thereof depending upon the piezoelectric actuators.

Driver for optical deflector using complex-sinusoidal-wave drive voltages and method for setting the same

An optical deflector includes a mirror having a reflective plane; a torsion bar extending outwardly from a side of said mirror; a support surrounding said mirror; a piezoelectric cantilever including a supporting body and a piezoelectric body formed on the supporting body, one end of said piezoelectric cantilever being connected to said torsion bar, the other end of the piezoelectric cantilever being connected to said support, said piezoelectric cantilever, upon application of a driving voltage to the piezoelectric body, exhibiting a bending deformation due to piezoelectricity so as to rotate said torsion bar, thereby rotarily driving said mirror through said torsion bar; and an impact attenuator connected to said support, the impact attenuator being disposed in a gap between said mirror and said support.

An optical deflector includes a mirror having a reflective plane; a torsion bar extending outwardly from an end of said mirror; a support surrounding said mirror; a first piezoelectric element, one end of said first piezoelectric element being connected to said torsion bar, the other end of the first piezoelectric element being connected to and supported by said support, said first piezoelectric element having at least one piezoelectric cantilever, the cantilever including a supporting body and a piezoelectric body formed on the supporting body to exhibit bending deformation due to piezoelectricity when a driving voltage is applied to the piezoelectric body, said piezoelectric element rotarily driving said mirror through said torsion bar when said driving voltage is applied; and a second piezoelectric element, one end of said second piezoelectric element being connected to said torsion bar, the other end of the second piezoelectric element being connected to and supported by said mirror.

Growing community of inventors

Tokyo, Japan

Takanori Aimono