Abstract: A spherical aberration correction mechanism 30 includes a lens holder 35 that holds a collimator lens 16, a main shaft 36a that supports the lens holder 35 in a linearly movable manner, a lead screw 34 supported in a rotatable manner and provided with a screw thread formed of a first slope and a second slope each in a spiral shape on an outer circumference thereof, and a stepping motor 13 that rotates the lead screw 34. The lens holder 35 includes a rack portion 41 disposed between the main shaft 36a and the lead screw 34 and having a slope that abuts on the first slope and first and second stoppers 46a and 46b that regulate a relative position of the rack portion 41 with respect to the lead screw 34 so that the rack portion 41 does not abut on the second slope.

Abstract: In a setup period of a first SF, a first ramp waveform (L2) that drops from a first potential (Vsus) to a second potential (?Vad+Vset2) is applied to scan electrodes belonging to a first scan electrode group. On the other hand, a second ramp waveform (L3) that drops from a third potential (Vsus+Vscn) higher than the first potential (Vsus) to a fourth potential (?Vad+Vscn) higher than the second potential (?Vad+Vset2) is applied to scan electrodes belonging to a second scan electrode group. In addition, a scan pulse (Pa) is sequentially applied to the scan electrodes belonging to the first scan electrode group, and then a third ramp waveform (L4) that drops to the second potential (?Vad+Vset2) and a scan pulse (Pa) are sequentially applied to the scan electrodes belonging to the second scan electrode group in a write period of the first SF.

Abstract: A stable address discharge is generated to achieve a high quality of image display. For this purpose, a plasma display panel, a scan electrode driving circuit, and a partial light-emitting rate detecting circuit are provided. The scan electrode driving circuit performs an address operation by sequentially applying a scan pulse to scan electrodes in an address period. The partial light-emitting rate detecting circuit divides the display area of the plasma display panel into a plurality of regions, and detects a rate of the number of discharge cells to be lit with respect to the number of discharge cells, as a partial light-emitting rate, in each of the regions. The scan electrode driving circuit performs the address operation earlier on the regions having the higher light-emitting rates detected in the partial light-emitting rate detecting circuit in decreasing order of value.

Abstract: An optical disk recording/reproducing device includes a turntable 7 configured to rotate an optical disk 9 and an optical head 3 configured to record/reproduce information in/from the optical disk 9. A stepping motor 13 to drive a collimator lens 16 is mounted on a head base 17 of the optical head 3 and a part of stator 42 of the stepping motor 13 is exposed through an opening 14a of a head cover 14, an opening 15a of a flexible substrate 15, an opening 13a of a cover 41, and an opening 13b of the cover 41.

Abstract: A motor controller (101) according to the invention comprises an inverter circuit (3) for driving a brushless motor (4) and a control unit for controlling the rotational speed of the brushless motor (4) by controlling the phase of the motor current of the brushless motor (4) through the inverter circuit (3).

Abstract: A converter circuit for converting an output voltage from an AC power supply includes a rectifier circuit for rectifying the output voltage of the AC power supply; first and second capacitors connected in series, for smoothing the output of the rectifier circuit; and a switch circuit for switching the connections between the respective capacitors and the AC power supply so that the output voltage of the AC power supply is applied to each of the respective capacitors at a cycle that is shorter than the cycle of the AC power supply.

Abstract: A PDP driving circuit and a plasma display apparatus with high image quality are realized. The PDP driving circuit of the present invention has a function of lowering the voltage of a recovery capacitor by connecting a step-up circuit including at least an inductor, a switch element, and a diode to the recovery capacitor, and regenerating the excessive voltage of the recovery capacitor to a sustain voltage power supply. Since the luminance can be lowered even in time of light load with low lighting rate by lowering the voltage of the recovery capacitor in time of low lighting rate, a high tone image display is realized, and the PDP driving circuit and the plasma display apparatus with high image quality are realized. In the data electrode driving circuit with slower write timing, the write operation is stabilized by raising the voltage of the recovery capacitor, whereby the PDP driving circuit and the plasma display apparatus with high image quality are realized.

Abstract: An optical head device has at least one upward-reflecting mirror, objective lenses, an objective lens actuator, and a moving mechanism. The upward-reflecting mirror receives an incident luminous flux having a wavelength emitted from a semiconductor, and changes its direction. The objective lenses having mutually different numerical apertures condenses the luminous flux whose direction has been changed by the upward-reflecting mirror to radiate a condensed luminous flux onto an information recording medium. The objective lens actuator moves the objective lenses in the focus direction of the information recording medium so that the luminous flux incident on the information recording medium becomes in a focused state. The moving mechanism moves the upward-reflecting mirror so that the luminous flux is incident on the information recording medium via any one of the objective lenses.

Abstract: An object of the present invention is to provide a PDP driving circuit and a plasma display apparatus each of which controls a discharge current at the time of sustain discharge by carrying out a switching operation during a power source clamping while changing a turn-on time, so as to display an image whose brightness is suppressed without deteriorating the gray scale. A PDP driving circuit (701) for driving a PDP (10) is constructed by connecting in parallel at least two switching elements (S51, S52) whose turn-on times are different from each other such that the switching elements (S51, S52) can be controlled independently as switches for applying a predetermined potential to scan electrodes and sustain electrodes.

Abstract: A drive circuit for driving a plasma display panel (PDP) includes a pulse voltage generation circuit (5101) that contains main switching elements disposed on the high voltage side and on the low voltage side, is operable to generate a pulse voltage by operating the main switching elements in accordance with an output voltage from a first power supply (V1) and apply the pulse voltage to a PDP scan electrode and sustain electrode, and a reset voltage generation circuit (52) operable to generate a reset voltage in accordance with an output voltage from a second power supply (V2) and apply it to the PDP. The pulse voltage generator C circuit contains a first diode (D11) that prevents the voltage outputted by the reset voltage generation circuit from being applied backward to the first power supply and a first switching element (S11) connected to the first diode in parallel.

Abstract: An optical head device is provided with a light source 1 for emitting a plurality of lights having different wavelengths, an objective lens 31 for focusing a light spot on an optical disc 21, an objective lens 32 for focusing light spots on optical discs 22 to 24, and a prism 53 for splitting a laser light having a wavelength of 405 nm from the light source 1 into a transmitting light and a reflected light, introducing the reflected light to the objective lens 31 and the transmitting light to the objective lens 32, and introducing laser lights having wavelengths of 660 nm, 780 nm from the light source 1 to the objective lens 32.

Abstract: A reset pulse generating section applies the total of voltages of a positive voltage source and two constant-voltage sources from a high side ramp wave generating section to a high side scan switching device as the upper limit of a reset voltage pulse, and applies the ground potential from a low side ramp wave generating section to a low side scan switching device as the lower limit of the reset voltage pulse. A sustaining pulse generating section applies the upper and lower limits of a sustaining voltage pulse through a common sustaining pulse transmission path to the low side scan switching device.

Abstract: An optical pickup device has a first light source and a second light source each adapted for outputting a laser beam of a predetermined wavelength, a photodetector for detecting an intensity of the laser beam outputted from the first light source or the second light source to control the power of the laser beam to be outputted from the first light source or the second light source, a wideband quarter wavelength plate for converting the laser beam outputted from the first light source or the second light source into a circularly polarized laser beam, and a first rise-up mirror and a second rise-up mirror for guiding a P-polarized component in the laser beam converted by the wideband quarter wavelength plate to the photodetector, and guiding an S-polarized component in the laser beam different from the P-polarized component to an optical recording medium.

Abstract: A housing 25 of a stepping motor 1 consists of a pair of case sections 27 arranged in front and rear in the direction of an axial line L of a rotating shaft 3. The case sections 27 are formed of: an end plate 27a to which a bearing 31 for supporting the rotating shaft 3 is fixed, and a base plate 27b and a top plate 27c extending from the end plate 27a in the direction of axial line L of the rotating shaft 3. The case sections 27 are formed by bending a single plate material.

Abstract: A motor driving apparatus includes an inverter circuit for converting an output of a rectifier circuit connected to a single-phase AC power supply into a driving voltage, and outputting the driving voltage to a brushless motor, and an inverter control unit for controlling the amplitude value of the voltage outputted from the inverter to the brushless motor so as to minimize a difference between a command rpm indicated by an external command signal and an actual rpm derived from an estimated phase of the rotor, wherein the command rpm is set to an rpm outside a predetermined range of rpms.

Abstract: An optical head includes the following: a light beam separator (35) that includes substantial interference regions for light that is reflected from an information recording medium and travels in a straight path and ±first-order diffracted light produced by information tracks of the information recording medium, and diffracts each of plural light beams in regions (32a, 32b) of the substantial interference regions, where the amount of light is changed by a change in the relative angle between the information recording medium and the objective lens and by a shift of the objective lens in the radial direction of the information recording medium; a light-receiving element (36a, 36b) for receiving the light beam that is reflected by the information recording medium and separated by the light beam separator (35); and an arithmetic circuit that corrects a value of an electrical signal detected by the light-receiving element (36a, 36b) in accordance with a radial position signal corresponding to the amount of shift of

Abstract: An integrated unit in which a light source and a light emitting diode are combined into one component is fixed to an optical bench. Then, relative position adjustment of an objective lens actuator is carried out with respect to the optical bench so that a desired detection signal can be obtained through reflected light from a disk information recording medium and then the objective lens actuator is fixed. The relative position adjustment of the integrated unit is no longer required and it is no longer necessary preliminarily to provide a margin for adjusting the integrated unit. Thus, an optical head can be reduced in size and thickness.

Abstract: A converter circuit for converting an output voltage from an AC power supply includes a rectifier circuit for rectifying the output voltage of the AC power supply; first and second capacitors connected in series, for smoothing the output of the rectifier circuit; and a switch circuit for switching the connections between the respective capacitors and the AC power supply so that the output voltage of the AC power supply is applied to each of the respective capacitors at a cycle that is shorter than the cycle of the AC power supply.

Abstract: A motor driving apparatus for driving a motor includes a single-phase rectifier circuit having an input connected to a single-phase AC power supply, an inverter circuit that is connected to the single-phase rectifier circuit and applies a current and a voltage to the motor, and an inverter control unit for controlling the inverter circuit. The inverter control unit controls the current applied to the motor, i.e., the output of the inverter circuit, so that the inverter input voltage becomes equal to the absolute value of the voltage of the single-phase AC power supply.

Abstract: A motor generator is provided with a stator having a winding around each of a plurality of stator teeth, and a rotor having a plurality of permanent magnets by the number larger than that of the stator teeth, arranged in the circumferential direction at equal intervals. The stator teeth are formed of a first stator teeth section including a plurality of stator teeth groups I, II, and III each including the adjacent stator teeth around which a winding to which the same phase voltage is applied is wound and in which winding directions of the stator teeth are opposite to each other, and a second stator teeth section including a stator teeth having a winding wound therearound and being placed among stator teeth groups of different phases such that electric power is independently input and output with respect to the first and second winding sections.