Abstract: In a disk drive apparatus of the present invention, power transistors of a power supplying part execute high-frequency switching operation and form current paths to three-phase windings so as to rotate a disk, a position detecting part produces a position signal which responds with terminal voltages of the three-phase windings, an activation operation part controls active periods of the power transistors in response to an output signal of the position detecting part, a commanding part produces a command signal in response to an output pulse signal of the position detecting part, and a switching operation block produces a switching pulse signal in response to a comparison result of a current detection signal with the command signal.

Abstract: A disk drive apparatus reproduces an information signal from a disk and/or records an information signal on the disk. FET power transistors of a power supplying part execute high-frequency switching operation and form current paths to three-phase windings so as to rotate the disk. A voltage detecting part compares terminal voltages of the three-phase windings and produces a detected pulse signal in response to a comparison result. An activation operation block controls active periods of the FET power transistors in response to the detected pulse signal. A commanding part produces a command signal in response to an output pulse signal of the voltage detecting part. A switching operation block produces a switching pulse signal in response to a comparison result of a current-detection signal with the command signal, and causes at least an FET power transistor of the power supplying part to perform high-frequency switching in response to the switching pulse signal.

Abstract: A disk drive apparatus reproduces an information signal from a disk with a head, and outputs a processed information signal from the reproduced signal of the head. A movable member having a field part which generates field fluxes is coupled to the disk so as to rotate the disk directly. First FET power transistors of first power amplifying parts and second FET power transistors of second power amplifying parts form current paths from a DC power source to three-phase windings. Three-phase first amplified current signals varying smoothly in rising and falling slopes are supplied to conduction control terminal sides of the first power amplifying parts. Three-phase second amplified current signals varying smoothly in rising and falling slopes are supplied to conduction control terminal sides of the second power amplifying parts.

Abstract: FET power transistors of a power supplying part execute high-frequency switching operation and form current paths to three-phase windings. A voltage detecting part compares terminal voltages of the three-phase windings and produces a detected pulse signal in response to a comparison result. A state shifting part and an activation control part control active periods of the FET power transistors in response to the detected pulse signal. A commanding part produces a command signal in response to an output pulse signal of the voltage detecting means. A switching operation block produces a switching pulse signal in response to a comparison result of a current-detection signal with the command signal, and causes at least an FET power transistor of the power supplying part to perform high-frequency switching in response to the switching pulse signal.

Abstract: A disk drive apparatus comprises a movable member having a field part for driving a disk. A current path is formed from a DC power supply into one winding of a Q-phase winding of the movable member by a first FET power transistor of a first power amplifier and a second FET power transistor of a second power amplifier. The first power amplifier amplifies an input current into a conduction control terminal side using the first FET power transistor. The second power amplifier amplifies the input current into the conduction control terminal side using the second FET power transistor. A switching control part simultaneously controls Q conduction control terminal sides of the first power amplifying means in an on and an off state and causes the first FET power transistor of the first power amplifying means to perform an on and off high-frequency switching.

Abstract: First power transistors of first power amplifying parts and second power transistors of second power amplifying parts form current paths from a DC power source to three-phase windings. A first distribution control block activates the first power amplifying parts with first three-phase signals, each having an active electrical angle larger than 120 degrees. A second distribution control block activates the second power amplifying parts with second three-phase signals, each having an active electrical angle larger than 120 degrees. A switching operation block has a current detecting part and a switching control part. The current detecting part obtains a current detected signal corresponding to a composed supply current of negative or positive parts of the three-phase drive currents to the three-phase windings.

Abstract: In the present invention, a Q-phase motor, which electronically switches current paths to plural-phase windings, comprises waveform shaping signal producing device for producing Q-phase waveform shaping signals having a conduction width larger than an electric angle of 360/Q degrees and superimposed signal producing device for superimposing signals to the waveform shaping signals. The superimposed signal producing device comprises superimposed timing producing device for producing superimposed timing signals which are output in a period shorter than a conduction period of the waveform shaping signals in a conduction period of the waveform shaping signals, synchronous rectifying control device for controlling the timing for synchronous rectification, and superimposed signal composing device for composing the signals output from the synchronous rectifying control device with the superimposed timing signals.

Abstract: In a motor and a disk drive apparatus using the motor, a switching control part produces a PWM pulse signal in response to the comparison result between a current detected signal and a command signal. An activate control part determines the active periods of power transistors in response to the holding state of the state holding part, and performs high-frequency switching operation to turn ON/OFF the power transistors in response to the PWM pulse signal of the switching control part. Furthermore, a voltage detecting part stops the detection of terminal voltages for a predetermined time in response to the PWM operation by the switching control part. After the stop, the voltage detecting part resumes the detection of the terminal voltages. This prevents improper detection caused by PWM noise.

Abstract: A disk drive apparatus reproduces an information signal from a disk with a head, and outputs a processed information signal from the reproduced signal of the head. A movable member having a field part which generates field fluxes is coupled to the disk so as to rotate the disk directly. First FET power transistors of first power amplifying parts and second FET power transistors of second power amplifying parts form current paths from a DC power source to three-phase windings. Three-phase first amplified current signals varying smoothly in rising and falling slopes are supplied to conduction control terminal sides of the first power amplifying parts. Three-phase second amplified current signals varying smoothly in rising and falling slopes are supplied to conduction control terminal sides of the second power amplifying parts.

Abstract: A conversion control part controls a converted DC voltage of a voltage converting part. The converted DC voltage is supplied to first and second amplifying parts each including a FET power transistor. At least one of first power transistors of first power amplifying parts and at least one of second power transistors of second power amplifying parts perform a full ON operation, thereby analoguely altering a current path from the converted DC voltage of the voltage converting part to plural-phase windings. This configuration reduces powerless and vibration of a motor.

Abstract: A recording and reproducing apparatus is disclosed in which video signal and indexing signal are separately recorded in video signal areas and subcode areas, respectively, of diagonal tracks formed on a tape by a rotating head. The apparatus has a tape driver for driving the tape, add/erase command keys for generating add/erase command to add/erase the indexing signal, an indexing signal control for setting and resetting the indexing signal, and a recording device for recording the video signal to the video signal area and, if any, the indexing signal to the subcode area of each track. An editing control is provided for controlling the indexing signal control in response to the add/erase command such that the indexing signal is first recorded as a reset state for a first predetermined amount and then recorded as a set state.

Abstract: A recording and reproducing apparatus is disclosed in which video signal and indexing signal are separately recorded in video signal areas and subcode areas, respectively, of diagonal tracks formed on a tape by a rotating head. The apparatus has a tape driver for driving the tape, add/erase command keys for generating add/erase command to add/erase the indexing signal, an indexing signal control for setting and resetting the indexing signal, and a recording device for recording the video signal to the video signal area and, if any, the indexing signal to the subcode area of each track. An editing control is provided for controlling the indexing signal control in response to the add/erase command such that the indexing signal is first recorded as a reset state for a first predetermined amount and then recorded as a set state.

Abstract: A video data is accompanied or multiplexed with one or more flags indicating a relation between fields or frames of video data for transmission or recording. An interlace flag determines whether the video data is interlaced or not. A still image flag determines whether the video data carries a motion image, a field still image, or a frame still image. A frame change flag determines whether or not a given frame of the still image is identical to its previous frame. At least one of the three different flags is multiplexed with its relevant video data.

Abstract: First FET power transistors of first power amplifying parts and second FET power transistors of second power amplifying parts form current paths from a DC power source to three-phase windings. Three-phase first amplified current signals varying smoothly in rising and falling slopes are supplied to conduction control terminal sides of the first power amplifying parts. Three-phase second amplified current signals varying smoothly in rising and falling slopes are supplied to conduction control terminal sides of the second power amplifying parts. A switching control part performs simultaneous on-off switching of the conduction control terminal sides of the first power amplifying parts, thereby causing first FET power transistors of the first power amplifying parts to perform high-frequency on-off switching. As a result, three-phase drive currents to the windings vary smoothly, thereby reducing motor vibration.

Abstract: In a brushless motor having a field permanent-magnet part, an altering signal producing circuit produces altering signals which vary analogously with output signals of a position detector. Then, at least one distributing circuit distributes current to first and/or second three-phase distributed current signals which vary analogously with the output signals of the altering signals. The first and/or second distributed current signals may be composed by a distributing composer to produce three-phase distributed signals. A driving block uses the three-phase distributed signals to produce driving signals for the three-phase coils.

Abstract: As shown in FIG. 9, a switching control part 310 detects voltage drops of FET power transistors 81 to 83, and outputs a switching control signal Vd responding with a modulated signal changed in synchronization with a movement of a motor, and a detected operation voltage. The switching operation of a switching transistor 61 is controlled responding with the switching control signal Vd, so that a converted DC voltage of a voltage converting part 52 is controlled. The converted DC voltage of the voltage converting part is supplied to power amplifying parts 11 to 17. The power amplifying parts configured by FET power current-mirror circuits analoguely alter current paths from the converted DC voltage of the voltage converting part to three-phase windings 2, 3, and 4, whereby pulsation of drive currents I1, I2, and I3 to the windings is reduced and a motor vibration is decreased in level.

Abstract: A brushless motor has a field part 20, three-phase coils 21, 22, and 23, a drive block 40 for supplying a power to the coils in accordance with output signals of a position detecting block 30, and a rotation detecting block 10 for producing a rotation signal and a direction signal by using output signals of the position detecting block 30. The rotation detecting block 10 has a shaped position signal producing circuit 11 for producing plural-phase shaped position signals, a rotation signal producing circuit 12 for producing the rotation signal synchronized with the shaped position signals, and a direction signal producing circuit 13 for producing the direction signal in correspondence with levels of the shaped position signals at a timing of a level change of the rotation signal.

Abstract: In a brushless motor having a field permanent-magnet part (10), an altering signal producing circuit (22) produces altering signals which vary analogously with output signals of a position detector (21). Then, a first distributing circuit (31) and a second distributing circuit (32) distributes first and second output current signals of a command block 15 to first and second three-phase distributed current signals which vary analogously with the altering signals. The first and second distributed current signals are composed by a distributing composer (33) to produce three-phase distributed signals. A driving block (14) uses the three-phase distributed signals to produce driving signals for the three-phase coils.

Abstract: A magnetic recording and reproducing apparatus includes: a recorder for recording information signals so as to form tracks obliquely on a magnetic tape, and for recording pilot signals so that the frequency may differ between different modes such as SP and LP; a reproducing head for reproducing recorded information; an error detecting circuit for comparing the level difference of pilot signals recorded in both tracks adjacent to the track to be scanned by there producing head and for outputting a tracking error signal; and a controller for controlling the feed of the magnetic tape so that the tracking error signal may be balanced. Preferably, in the LP mode, a pilot signal of a higher frequency than that used in the SP mode is recorded. In a tracking error detector for a magnetic recording and reproducing apparatus for detecting the pilot signal, the reproduced signals are sampled at a frequency at a common multiple of each pilot frequency, a pilot signal is detected, and a tracking error signal is output.

Abstract: The brushless motor has: a field unit having a rotor permanent magnet (12); three-phase driving windings (20A, 20B, and 20C) of the stator; driving transistors for supplying a power to the driving windings; a driving command unit (43) for generating sinusoidal driving command signals; and a driving unit which supplies to the driving windings sinusoidal driving currents in accordance with the driving command signals. The driving command unit (43) consists of: a time interval measurement device (42) which measures timing intervals from a pulse signal of a rotation detector (41), the timing intervals being inversely proportional to the rotational speed of the rotor; and a driving command generation unit (43) which changes an estimated electric angle at time intervals responding to the measurement result of the time interval measurement device thereby to generate the sinusoidal driving command signals corresponding to the estimated electric angle.