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 first switch circuit includes first and second N-type MOSFETs. A second switch circuit includes third and fourth N-type MOSFETs. A control signal is input to a first inverter and a third inverter, the output of the first inverter input to a second inverter and the gate of the fourth MOSFET, the output of the second inverter input to the gate of the first MOSFET, the output of the third inverter input to a fourth inverter and the gate of the third MOSFET, the output of the fourth inverter input to the gate of the second MOSFET. A first input voltage is connected to the source of the second MOSFET and the sources of N-type MOSFETS in the third and fourth inverters. A second input voltage is connected the source of the fourth MOSFET and the sources of N-type MOSFETS in the first and second inverters.

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: The tensile strength of the first fixing member is larger than the tensile strength of the second fixing member. When the attaching and detaching of the cutting tool is repeated, although the second fixing member having a smaller tensile strength gets deteriorated, it is sufficient to replace the second fixing member, and it is possible to prevent breakage of the first fixing member, and it is possible to reduce the frequency of replacing the vibration body. As the material for first fixing member, it is possible to use high-speed steel, cemented carbide, SCM steel (chrome molybdenum steel), etc. As the material for the second fixing member, it is possible to use cemented carbide, SCM steel, etc.

Abstract: In a cutting tool, a shank is a support member made of ceramics and although it is light, it is hardly bent. Further, a processing tip made of a diamond having a cutting edge and is fixed to the tip portion of the shank by an active metal method or brazing. The shank is fixed so as to be pressed to the bottom surface of a slit-shaped groove formed in a fixing portion by a fixing screw and a washer. In this case, the washer is a ring-shaped member transforming as a cushioning member and prevents the fastening stress by the fixing screw from locally concentrating.

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: 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 voltage selection circuit is disclosed which comprises: a first through a fourth inverters; a first switch circuit including a first MOSFET of N type and a second MOSFET of N type, respective drains thereof being connected in common; and a second switch circuit including a third MOSFET of N type and a fourth MOSFET of N type, respective drains thereof being connected in common, a common drive voltage being input to the first through fourth inverters, a control signal being input to the first inverter and the third inverter, the output of the first inverter being input to the second inverter and the gate of the fourth MOSFET, the output of the second inverter being input to the gate of the first MOSFET, the output of the third inverter being input to the fourth inverter and the gate of the third MOSFET, the output of the fourth inverter being input to the gate of the second MOSFET, a first input voltage selected depending on the control signal being input to the source of the second MOSFET, a second input vo

Abstract: A machining method of machining a transfer optical surface on a optical element producing die having the transfer optical surface made of a material having Vickers hardness of Hv1500 or more, comprising: machining the transfer optical surface on the optical element producing die by cutting with a cutting tool, wherein a rake face of a tip of a blade of the cutting tool is set with an angle of minus values at an incising point on a surface to be machined.

Abstract: A method for making a lens molding replica die for molding a lens made of glass or a synthetic resin comprises the steps of: (1) making a master die having a reference surface; (2) forming a separating film on the master die; (3) forming an SiC film on the reference surface; (4) machining a surface of the die base member into a prescribed shape and machining the SiC film into a shape in conformity of the surface of the die base member; (5) bonding a die base member onto the SiC film; and (6) separating the SiC film bonded onto the die base member from the master die.

Abstract: A damping mechanism for clutch disc for use in an automobile clutch, including an axially compressible cushioning plate supporting a facing in between a flywheel and a pressure plate. In order for minimizing "resonance sound" of the cushioning plate due to axial vibration, a damping member for controlling the axial vibration of the cushioning plate is installed between the cushioning plate and the clutch plate.