Abstract: A vibration gyro having a structure for canceling a quadrature error generated by structural asymmetricity due to production tolerance and a means for correcting a bias value when an angular velocity is zero. In order to apply a counter torque to a sense mass for canceling the quadrature error, left correction comb electrodes are fixed to a substrate adjacent to a left drive mass, and comb electrodes opposed to the correction comb electrodes are arranged on an inner portion of a frame member which constitutes the left drive mass. By applying DC voltage to the correction electrodes, electrostatic force, for canceling the leakage rotational displacement of the sense mass generated when the input angular velocity is zero, is generated.

Abstract: A vibration gyro having a structure for canceling a quadrature error generated by structural asymmetricity due to production tolerance and a means for correcting a bias value when an angular velocity is zero. In order to apply a counter torque to a sense mass for canceling the quadrature error, left correction comb electrodes are fixed to a substrate adjacent to a left drive mass, and comb electrodes opposed to the correction comb electrodes are arranged on an inner portion of a frame member which constitutes the left drive mass. By applying DC voltage to the correction electrodes, electrostatic force, for canceling the leakage rotational displacement of the sense mass generated when the input angular velocity is zero, is generated.

Abstract: According to one of the aspects of the present invention, a vibratory gyroscope includes a pair of proof masses having the same inertia mass, each of the proof masses having a first axis. The proof masses are arranged symmetrically in relation to a second axis. Also, the vibratory gyroscope includes a pair of drive elements, each of which has a driving axis extending in parallel to the second axis and supports respective one of the proof masses to allow oscillation thereof about the first axis. Further, the vibratory gyroscope includes a supporting element with an anchor element for supporting the drive elements to allow oscillation thereof about the driving axes. Finally, the vibratory gyroscope includes a main body having an inner space for receiving the supporting element, in which the main body is in contact with the anchor element of the supporting element and spaced away from the proof masses and the drive elements.

Abstract: An inertial detecting device for detecting a change in capacitance of a sensor element caused by inertial force includes a displaceable unit. The displaceable unit includes a movable mass member which is displaceable in the direction of an inertial force and is supported in a space by a pair of beams fixed on the substrate. At least one pair of detection units for detecting the displacement of the displaceable unit are provided on the substrate. The detection unit includes a drive unit and a pair of sensing electrodes which are disposed opposite to the displaceable unit. Any gap can be freely set between the sensing electrode and the movable mass member, thereby changing the sensitivity of the detecting device in a wide range.

Abstract: An acceleration sensor includes first and second fixed electrodes on a substrate, and a movable electrode located above the first and second fixed electrodes, with respect to the substrate, and facing them. The movable electrode is elastically supported on the substrate by a first elastic supporting body and is movable. A mass, which is elastically supported on the substrate by a second elastic supporting body, moves in response to an acceleration in a direction perpendicular to the substrate. A linking portion links the movable electrode and the mass at a position spaced from an axis of movement of the movable electrode by a distance. Acceleration is measured based on changes in a first capacitance between the first fixed electrode and the movable electrode and a second capacitance between the second fixed electrode and the movable electrode. Thus, a highly impact resistant and highly reliable acceleration sensor is obtained.

Abstract: A tunable semiconductor laser apparatus with an external resonator includes: a semiconductor laser device having a first end face and a second end face, the second end face being coated with an antireflection film; an optical device for collimating light emitted from the second end face; a reflecting device for reflecting the collimated light, the reflecting device and the first end face constituting an external resonator; a tunable device located between the optical device and the reflecting device; and a driving mechanism for angularly displacing the tunable device to control incidence angle of light onto the tunable device, wherein the driving mechanism includes a micro-machine actuator, thereby shortening the length of the external resonator, yet providing a wide tunable range, reducing the size of the apparatus while achieving excellent mass-productivity.

Abstract: An inertial detecting device for detecting a change in capacitance of a sensor element caused by inertial force includes a displaceable unit. The displaceable unit includes a movable mass member which is displaceable in the direction of an inertial force and is supported in a space by a pair of beams fixed on the substrate. At least one pair of detection units for detecting the displacement of the displaceable unit are provided on the substrate. The detection unit includes a drive unit and a pair of sensing electrodes which are disposed opposite to the displaceable unit. Any gap can be freely set between the sensing electrode and the movable mass member, thereby changing the sensitivity of the detecting device in a wide range.

Abstract: An acceleration sensor includes first and second fixed electrodes on a substrate, and a movable electrode located above the first and second fixed electrodes facing them. The movable electrode is elastically supported on the substrate by a first elastic supporting body and is movable. A mass, which is elastically supported on the substrate by a second elastically supporting body moves in response to an acceleration in a direction perpendicular to the substrate. A linking portion links the movable electrode and the mass at a position spaced from an axis of movement of the movable electrode by a distance. Acceleration is measured based on changes in a first capacitance between the first fixed electrode and the movable electrode and a second capacitance between the second fixed electrode and the movable electrode. Thus, a high impact resistant and highly reliable acceleration sensor is obtained.

Abstract: First and second fixed electrodes provided on a substrate, a movable electrode which is provided above the first and second fixed electrodes facing against them, and is elastically supported on the substrate by a first elastic supporting body and is swingable, a mass which is elastically supported on the substrate by a second elastically supporting body and is movable in response to an acceleration in a direction perpendicular to the substrate, and a linking portion for linking the movable electrode and the mass at a position away from a swing axis of the movable electrode by a predetermined distance are provided. An acceleration is measured based on changes in a first capacitance provided by the first fixed electrode and the movable electrode and a second capacitance provided by the second fixed electrode and the movable electrode. Thus, a high impact resistant and highly reliable acceleration sensor can be obtained.

Abstract: A sensitive angular velocity sensor is provided without increasing an inter-electrode gap for inducing a torsional vibration.

Abstract: A conventional angular rate sensor has a problem that the displacement amplitude of a drive gimbal frame is limited due to the Pulled-in phenomenon where the drive gimbal frame is attached to drive electrodes, thereby decreasing its sensor sensitivity. In an angular rate sensor, a drive frame and a driven frame are separately provided. A bending oscillation of the drive frame is transmitted to the driven frame through link beams, causing the rotational oscillation of the driven frame. The displacement amplitude of a rotational oscillation of the driven frame is not limited to provide high sensor sensitivity.

Abstract: A sensitive angular velocity sensor is provided without increasing an inter-electrode gap for inducing a torsional vibration.

Abstract: A capacitance detecting circuit which can ensure flexibility in application without restriction imposed by a capacitance arrangement such as a single capacitance, differential capacitance, differential capacitance electrostatic servo and like arrangements, to a great advantage includes an operational amplifier having an inverting input terminal and an output terminal between which a feedback capacitance component is connected, a capacitance sensor having an electrostatic capacitance subjected to change under action of an external force, a switch for electrically charging the capacitance component of the capacitance sensor by connecting a charge/discharge terminal of the capacitance component to a reference voltage at a first clock timing for discharging the feedback capacitance component and switching the charge/discharge terminal to the feedback capacitance component at a second clock timing to transfer electric charge, and a sample-and-hold circuit for converting the transferred electric charge to the senso

Abstract: A micro-mirror device includes a mirror forming substrate on which a mirror is disposed. A pair of torsion beams are disposed on opposing sides of the mirror forming substrate. An anchor projects from a supporting substrate, supporting the ends of the torsion beams. A driving frame surrounds at least one side of the torsion beams and is connected to the mirror forming substrate through a link beam. A drive force generator drives the driving frame.

Abstract: A movable electrode structure is formed in a single sensor element, and this movable electrode structure can be displaced along two axes within a plane, and one axis outside the plane. A detecting fixed electrode is provided via a constant space with each of these detecting axes, and a change in capacitances between the movable electrodes and the fixed electrodes is detected. As a result, the acceleration components of the two axes, or the three axes are detected. The dynamic characteristic of the sensor is controlled based on the mass of the variable electrode, the structure and length of the beam for supporting the movable electrode, and also the ratio of the length to the section of this beam.

Abstract: A pressure switch with improved sealing of an airtight chamber, and improved electrical characteristics reducing chattering, increasing response rate, and minimizing the pressure necessary for activation. The pressure switch includes an upper substrate with a diaphragm readily deformed by an applied stress, a lower substrate overlapped with the upper substrate to form the airtight chamber, a contact electrically switched in response to the deformation of the diaphragm, and a sealing member continuously surrounding the airtight chamber, disposed between the first and second substrate, and hermetically sealing the airtight chamber.

Abstract: A vibrating type angular velocity sensor is comprised of: a driving vibrator element 8 supported by a first beam 9 fixed by an anchor portion 3 on a substrate, and driven by a driving comb electrode 12 along an X-axial direction parallel to the substrate; a detecting vibrator element 10 supported by a second beam 11 on the driving vibrator element and being vibratable along a Y-axial direction; and detection electrodes 14 and 15 of an electric capacitance provided with separated from the detecting vibrator element, and the detection electrodes along the X-axial direction, whereby an angular velocity while setting a Z-axial direction perpendicular to the substrate as an axis is detected. Furthermore, the driving vibrator element is fixed on the substrate by way of two sets of the anchor portions arranged at positions symmetrical to each other with respect to the detecting vibrator element.

Abstract: A semiconductor accelerometer switch having a fixed portion including a first control electrode and a movable portion including a movable body. By applying a voltage between the first control electrode and an electrode on the movable body, electrostatic attraction holds the movable body in an initial position. The movable body is displaced when acceleration having a magnitude in a direction acts on the switch. The threshold of acceleration to be detected and general-purpose properties of the accelerometer switch are easily adjusted.

Abstract: An interface circuit for a capacitive sensor capable of outputting a detection signal with high stability and reliability while suppressing to a minimum the influence of offset and temperature dependency onto the output signal. In a differential capacitance type sensor having a common electrode connected to the ground potential, an electric discharge redistributing method and impedance conversion technique are adopted for obtaining an output voltage which is in proportion to the inter-electrode relative displacement. A switching mechanism is provided for mitigating an offset voltage component contained in the output due to an input offset voltage of the operational amplifier. Further, the sensitivity of the capacitive sensor is increased with the temperature-dependent drift of the sensor output being suppressed by providing additionally a power source change-over switches for allowing the voltages sampled in response to predetermined clocks to be differentially amplified.

Abstract: A method of micromachining a silicon wafer that simultaneously forms narrow gaps having a width of 10 .mu.m or less and wider gap portions using an anistropic etching solution. The etching solution contains KOH in a concentration of 35% or less and the penetration etching is carried out such that the etching of the opposing walls and the face of the silicon wafer occur at the same rate. A method of manufacturing a capacitance-type acceleration detector in a silicon wafer using the aforementioned etching method.