Abstract: A motor drive circuit configured to supply drive currents to drive coils with a plurality of phases of a motor to drive the motor, includes: a trapezoidal wave signal generation circuit configured to output a trapezoidal wave signal whose inclination is changed with a rotation speed of the motor or a target rotation speed of the motor; and a plurality of output transistors configured to output the drive current to the drive coils, respectively, in accordance with the trapezoidal wave signal.

Abstract: A motor drive circuit comprising: a triangle wave generation circuit configured to charge/discharge a capacitor with a charging/discharging current having a current amount corresponding to an amplitude control voltage for controlling an amplitude of an oscillation voltage that varies in a triangle wave shape, and to output a charging voltage of the capacitor as the oscillation voltage; a pulse signal generation circuit configured to generate a pulse signal having a duty ratio corresponding to a level of a speed control voltage for controlling a rotational speed of a motor, based on a comparison result between the speed control voltage and the oscillation voltage output from the triangle wave generation circuit; and a drive circuit configured to intermittently drive a motor coil based on the pulse signal.

Abstract: In a vibration cutting unit, a root portion of a holding member for supporting a vibration body is fixed on a fixed portion of a node portion which is common to axial vibration and bending vibration, on a jointless basis. Therefore, the node portion, namely, a vibration body main part is firmly fixed, thereby, the vibration body main part is supported stably, and vibrations of the vibration body main part is stabilized. In other words, vibrations under the mode where the vibration body main part cannot be controlled can be restrained, and works representing objects to be processed can be processed accurately.

Abstract: A motor drive circuit to drive a motor coil based on duty ratio of a PWM signal, includes: a first pulse signal generating circuit to generate a first pulse signal for each time period, the time period being equal to 1/n of a time period during which the PWM signal is at one logic level; a counter to change a count value based on the first pulse signal; a drive signal output circuit to output a drive signal of one logic level when the count value is not a predetermined value, and output the drive signal of the other logic level when the count value reaches the predetermined value; a drive circuit to perform PWM driving for the motor coil based on the duty ratio of the drive signal; and a setting circuit to set, in the counter, such a count value as to decrease a current passing through the motor coil, for each period of the PWM signal, in a time period during which the current passing through the motor coil is decreased, and set, in the counter, such a count value as to increase the current passing through th

Abstract: A motor drive circuit comprising: first and second transistors connected in series, a voltage of a connection-point therebetween being a drive-voltage applied to one end of a motor coil; an operational amplifier for controlling the transistors such that the drive-voltage is a voltage according to a difference between first and second control voltages; a switch circuit for driving the transistors such that the motor coil is in an undriven state regardless of control by the operational amplifier when a pulse-signal is at one logic level, and driving the transistors based on the control when the pulse-signal is at the other logic level; and an auxiliary drive circuit for driving the transistors to increase the drive-voltage for a predetermined time period shorter than a time period of the pulse signal being at the other level regardless of the control, when the pulse-signal changes from the one level to the other.

Abstract: A motor drive circuit includes a first amplifier circuit to amplify a difference between first and second position detection signals with a gain becoming smaller according to drop in power supply voltage, to output a first amplification signal, the first and second position detection signals being signals indicating a rotational position of a rotor in a motor, having a frequency corresponding to a rotation speed of the motor, and being opposite in phase to each other; a second amplifier circuit to amplify the difference between the first and second position detection signals with the gain, to output a second amplification signal opposite in phase to the first amplification signal; and a drive circuit to amplify the difference between the first amplification signal and the second amplification signal with a predetermined gain to be saturated at the power supply voltage, to output a driving voltage for driving the motor.

Abstract: A device for producing a wafer lens, including: a stage which supports a glass substrate; an XY-axis moving mechanism which moves the stage on an XY-plane; an XY air slide guide mechanism which floats the stage relative to an XY guide by means of air, and guides the movement of the stage; a molding die to be filled with resin; a Z-axis moving mechanism which elevates or lowers the molding die; a Z air slide guide mechanism which floats the molding die relative to a Z guide by means of air, and guides the elevation and lowering of the molding die; and a control device which locks a moving position of the stage by controlling an activation and a deactivation of the XY air slide guide mechanism, and also locks a moving position of the molding die by controlling an activation or a deactivation of the Z air slide guide mechanism.

Abstract: Provided is a method of manufacturing a wafer lens in which the surface configuration of the lens section can be transferred with high precision. The method possesses a step of preparing a molding die having plural molding surfaces corresponding to an optical surface configuration of the optical member; a filling step of filling the photo-curable resin in between the surface of the substrate and the molding surface of the molding die; a photo-curing step of exposing the photo-curable resin to light to accelerate curing; a heating step of conducting a heat treatment for the photo-curable resin having been cured in the photo-curing step; and a releasing step of releasing the molding die from the photo-curable resin after conducting the heating step, and further comprises a step of conducting a post-cure treatment for the optical member.

Abstract: A motor-driving circuit includes: a plurality of output transistors; a first-comparator circuit to compare a voltage of each phase of driving coils of a plurality of phases in a motor, with a neutral-point voltage; a position-detecting circuit to detect a rotor position of the motor based on a comparison result of the first-comparator circuit; a switching-control circuit to supply switching signals to the plurality of output transistors according to the rotor position; and a current-limiting circuit to limit the driving currents to a first-current value so that the motor rotates at a target-rotation speed when the current-limiting circuit determines that the motor is rotating at a speed higher than or equal to a predetermined-reference-rotation speed, and limit the driving currents to a second-current value smaller than the first-current value when the current-limiting circuit determines that the motor is not rotating at the speed higher than or equal to the predetermined-reference-rotation speed.

Abstract: A motor drive circuit is configured to drive a motor based on first and second position detection signals opposite in phase to each other, the signals having a frequency corresponding to a rotational speed of the motor and indicating a rotational position of the motor. The circuit includes a first level-shift circuit, a second level-shift circuit, a timing detecting circuit, and an output circuit. The first level-shift circuit is configured to shift a level of at least either one of the first and second position detection signals so that a first period, during which a first output signal corresponding to the first position detection signal is higher in level than a second output signal corresponding to the second position detection signal, becomes longer than a second period, during which the second output signal is higher in level than the first output signal.

Abstract: Provided are a mold used to form a concave lens section and provided with a reference surface having improved flatness, a method of manufacturing the mold, a method of manufacturing a wafer lens by using the mold, and a wafer lens. The mold has one or more concave cavities formed in a base having a flat surface. A convex section is formed in each of the cavities, the convex section in the cavity is located below the surface of base (12).

Abstract: A motor drive circuit includes: a pulse generation circuit configured to generate a pulse signal whose duty ratio of one logic level is increased as a drive voltage is increased in accordance with a target rotation speed of a motor; and a drive control circuit that configured to drive the motor with the drive voltage using a duty ratio higher than the duty ratio of the pulse signal when the motor starts rotating from the stopped state, and configured to drive the motor with the drive voltage during a period when the pulse signal is at the one logic level after the motor starts rotating, based on a rotation signal corresponding to the rotation of the motor.

Abstract: The invention provides a motor with a low speed start function and a soft start function. The motor includes a first pulse generation circuit generating a first pulse signal of which a first duty ratio of one of logic levels is increased as a drive voltage corresponding the target rotation speed of the motor is increased, a second pulse generation circuit generating a second pulse signal of which a second duty ratio of one of logic levels is different from the first duty ratio, and a drive control circuit supplying a drive current to a motor coil at the second duty ratio in order to start the rotation of the motor that is stopping and supplying a drive current to the motor coil at the first duty ratio after a predetermined time passes from the start of the rotation of the motor in response to a rotation signal corresponding to the rotation of the motor.

Abstract: In the assembly of vibration body, the first width in the lateral direction (X axis direction) is greater than the second width in the longitudinal direction (Y axis direction) in the cross sectional form perpendicular to Z axis of the first portion on the tip side from the closest node position, thereby, the rigidity of a vibration body main part in the X axis direction can be enhanced, and lateral bending vibrations on fixing portion can be restrained. Consequently, an object can be processed highly accurately by the assembly of vibration body that is controlled with a high precision.

Abstract: A motor drive circuit includes a first amplifier circuit to amplify a difference between first and second position detection signals with a gain becoming smaller according to drop in power supply voltage, to output a first amplification signal, the first and second position detection signals being signals indicating a rotational position of a rotor in a motor, having a frequency corresponding to a rotation speed of the motor, and being opposite in phase to each other; a second amplifier circuit to amplify the difference between the first and second position detection signals with the gain, to output a second amplification signal opposite in phase to the first amplification signal; and a drive circuit to amplify the difference between the first amplification signal and the second amplification signal with a predetermined gain to be saturated at the power supply voltage, to output a driving voltage for driving the motor.

Abstract: Provided is a watch capable of performing digital display as well as analog display. The watch can offer digital display without posing disadvantages peculiar to a liquid crystal panel. On the other hand, the watch can reduce the restrictions in design and make the digital display larger and easier to see. The watch includes a light-shielding plate 22 on the rear side of the dial 24. In the light-shielding plate, light-transmitting holes 23 are made piercing from a front of the light-shielding plate to a rear thereof. Thin chip LEDs 17 are inserted in the light-transmitting holes, and mounted on a circuit board 16. The circuit board is placed on the rear side of the light-shielding plate. On the rear side of the circuit board, an analog movement 13 is provided, and an LED drive circuit 33 for driving the LEDs is placed. Thus, the LEDs 17 for digital display are placed on the rear side of the dial.

Abstract: A motor drive circuit comprising: a triangle wave generation circuit configured to charge/discharge a capacitor with a charging/discharging current having a current amount corresponding to an amplitude control voltage for controlling an amplitude of an oscillation voltage that varies in a triangle wave shape, and to output a charging voltage of the capacitor as the oscillation voltage; a pulse signal generation circuit configured to generate a pulse signal having a duty ratio corresponding to a level of a speed control voltage for controlling a rotational speed of a motor, based on a comparison result between the speed control voltage and the oscillation voltage output from the triangle wave generation circuit; and a drive circuit configured to intermittently drive a motor coil based on the pulse signal.

Abstract: A motor control circuit comprising: a rotation control circuit configured to control rotation of a motor based on a rotation control signal for controlling rotation of the motor and a rotational position detection signal from a Hall element for detecting a rotational position of the motor; a determining circuit configured to determine whether the rotation control signal has been generated for a predetermined time period; and a Hall element control circuit configured to apply a Hall element source voltage to the Hall element when the determining circuit determines that the rotation control signal has been generated for the predetermined time period, and to stop applying the Hall element source voltage to the Hall element when the determining circuit determines that the rotation control signal has not necessarily been generated for the predetermined time period.

Abstract: A motor drive circuit includes: a pulse generation circuit configured to generate a pulse signal whose duty ratio of one logic level is increased as a drive voltage is increased in accordance with a target rotation speed of a motor; and a drive control circuit that configured to drive the motor with the drive voltage using a duty ratio higher than the duty ratio of the pulse signal when the motor starts rotating from the stopped state, and configured to drive the motor with the drive voltage during a period when the pulse signal is at the one logic level after the motor starts rotating, based on a rotation signal corresponding to the rotation of the motor.

Abstract: A motor drive circuit comprising: a first transistor and a second transistor connected in series, a voltage of a connection point between the first transistor and the second transistor being a drive voltage applied to one end of a motor coil; an operational amplifier configured to control the first transistor and the second transistor such that the drive voltage is a voltage according to a difference between a first control voltage and a second control voltage for controlling driving of the motor coil; a switch circuit configured to drive the first transistor and the second transistor such that the motor coil is in a state of not being driven regardless of control by the operational amplifier when a pulse signal for intermittently driving the motor coil is at one logic level, and drive the first transistor and the second transistor based on the control by the operational amplifier when the pulse signal is at the other logic level; and an auxiliary drive circuit configured to drive the first transistor and the