摘要:
In a disk device, when processing is resumed after replacing the disk or cutting off the power supply, in order to acquire disk-related information in a short period of time and reduce the start-up time, the effectiveness of management information recorded on the disk is judged, the finding of the judgment is stored into a memory means capable of storing even when power supply is off, the management information is read out of some of the recording areas of the disk in advance of a recording or reproducing operation if the stored information on the finding of the judgment indicates effectiveness for the inserted disk.
摘要:
A VCR integrally provided with a camera (camcorder) stops power supply at a non-recording mode for reducing power consumption. The camcorder is arranged to have power control units and a switch for controlling the start or the end of the recording operation and the power-on or power-off of at least one or more of a camera section, a VCR section and a display section, a time measuring unit, and a control unit for starting the recording unit a predetermined time later than when the camera section starts to pick up an image sequence and the image sequence appears on an electronic viewfinder or the like. Further, the camcorder includes units for moving a zoom lens to a Wide-terminal when powered off, when powered on or a predetermined time later than when powered off. Moreover, there are provided units for overlapping text information with the image sequence appearing on the electronic viewfinder. These units display a time left until the recording start. The camcorder further provides units for varying a predetermined time left until the recording start and units for selecting a moving timing on which the zoom lens is moved to the Wide-terminal so that the user may freely set the predetermined time and the moving timing.
摘要:
The precedingly reproduction signal reproduced by a precedingly reproducing head is recorded on a tape. If it is detected that the reproduction signal includes abnormality owing to a reason such as poor error rate, the recording operation is stopped. Then, for retrial of the recording, the information on the position where the abnormality has occurred is held. A memory may be provided to always rewrite and store the signal reproduced by the precedingly reproducing head, and also a simultaneously reproducing head which is different from the precedingly reproducing head may be provided to immediately monitor the recording state of the signal recorded on the tape. If it is detected that the signal reproduced by the simultaneously reproducing head includes abnormality, the recording operation is stopped, the information on the position where the abnormality has occurred is held. Further, the rewrite operation in the memory is stopped and the original precedingly reproduction signal corresponding to the signal to be recorded at the position where the abnormality has occurred is held in the memory.
摘要:
A memory controlling apparatus for a magnetic recording and reproducing apparatus which records and reproduces a field image signal in each read or write cycle performed by a video head for reproducing the image signal from a magnetic tape, and by a video head position detector for detecting the position of the video head. A reference circuit obtains a signal defining a reference timing which is independent of the position of the video head and which is also used to determine the phase of the video head. A memory is provided having storage sufficient to store the field image signal, and a controller is provided for controlling the operation of reading and writing the image signal from and into the memory. The controller is synchronized with a signal of the video head position detector when storing the image signal into the memory and when reading out the image stored in the memory, the controller and the head position detector are synchronized with the reference timing so as to enable production of a slow-motion image signal free from fluctuations caused by feeding of the magnetic tape.
摘要:
In a slow-motion device of a helical scan type video tape recorder, detection is effected to detect a noise in a reproduced signal which is caused when the magnetic tape is fed such that the magnetic heads which have reproduced a preceding still image at a track transfer to the succeeding track and thereafter the magnetic heads scan the succeeding track, and the position of the magnetic tape is controlled by a tape control system so that the noise is confined within a position at a noise bar due to the noise is prevented from being displayed on the reproduction screen.
摘要:
An apparatus for driving a brushless motor, in which a ripple appearing in the rotation torque of the motor is cancelled by driving the motor with a signal current whose phase is opposite to that of and which has a waveform symmetrical with that of the torque ripple waveform, so that the motor can rotate accurately without any speed variation. In order to obtain such a signal current waveform, counter-electromotive forces induced in the stator coils of the motor are detected, and the level of the signal indicative of the detected counter-electromotive forces is controlled depending on the load and rotation speed of the motor to provide a control signal for controlling the motor drive current.
摘要:
A transistor circuit is used as a signal amplifier which has little possibility of oscillation in an IC. The transistor circuit includes a cascade connection of differential amplifiers. Each of the amplifiers comprises a differential pair of bipolar transistors and an enhancement-type MOSFET as a constant current source. The MOSFET of each amplifier is connected in the common source mode, and the drain is connected to the emitters of the differential pair of bipolar transistors. The sources of all the MOSFETs are connected to a common ground-line.
摘要:
A power supply in which a single variable voltage supply device is used as a power source for a plurality of motors which are simultaneously or successively rotated, in which each motor is subjected to constant current driving by a current control device connected to the motor, and in which the variable voltage supply device is controlled so as to produce a voltage which is the sum of the highest one of the voltages required for driving the motors and necessary and minimum voltage with which all the current control devices are operable.
摘要:
Disclosed is a drive system for a motor, wherein a current proportional to a change of a load of a motor is sensed by a sensing resistor. A voltage produced across the sensing resistor controls an electronic switch in a manner that the output DC voltage of a DC - DC converter is used for a motor drive power source at a normal load and yet a DC power source with a higher voltage than the output DC voltage of the DC - DC converter is used therefor at an increased load.
摘要:
A limiter circuit comprises a low-pass filter which passes only a modulation signal out of the modulation signal having pulsive noises superimposed thereon and circuit means for supplying the modulation signal extracted by the filter to current source circuits for a limiter differential amplifier to control the current source circuit for the limiter differential amplifier in accordance with a waveform of the input modulation signal applied thereto.