Abstract: A magnetic recording and reproducing device with an automatic tracking control function which can record and reproduce signals by means of a rotary head incorporating plural heads. The device performs tracking control by detecting, based on a timing of a synchronizing signal of a track, crosstalks of pilot signals obtained from adjacent tracks and comparing the crosstalks to use the difference as a tracking error signal. In a first example of the invention, the device comprises means which, when time points at which the tracking error signals is obtained are located at uneven time interval, transmits the tracking error signal to the tracking control system with a transfer gain which varies substantially in inverse proportion to the time interval. According to the invention, when the time interval for obtaining the tracking error signal is long, the transfer gain becomes low whereas when the time interval is short, the transfer gain becomes high.

Abstract: A magnetic recording and reproducing device of a type recording and reproducing a signal on a magnetic recording medium such as a tape by using a rotary head and performing a tracking control by detecting crosstalk components of pilot signals on left and right adjacent tracks and comparing these components with each other comprises a pilot signal detection circuit for detecting a pilot signal during fast feeding or rewinding of the magnetic recording medium and speed control circuit for controlling at least one of rotation speed of the rotary head and running speed of the magnetic recording medium so that the pilot signal can be detected substantially at its predetermined frequency during the fast feeding or the rewinding.

Abstract: A motor driving circuit capable of driving a motor with a single circuit regardless of whether the motor used is a brush motor or a brushless motor. The circuit detects a speed error between actual speed and commanded speed of the motor and provides a speed error signal. An inversion circuit selectively inverts or non-inverts the speed error signal in response to the type of the motor and desired motor rotation direction. When a brushless motor is used, the non-inverted error signal is employed for controlling driving of the motor. When a brush motor is used, the inverted speed error signal is employed.

Abstract: A magnetic recording and reproducing device comprises a rotary head incorporating plural heads having different azimuths and recording and reproducing an input signal by tracing a magnetic tape and a tape feeding drive device for feeding the magnetic tape. The tape feeding drive device feeds the magnetic tape during multiple speed reproduction with a tape feeding speed of about (N+1/2) times (where N is an integer) as high as a tape feeding speed during a normal speed reproduction. Positional relation of head trace to the track thereby is shifted by 1/2 track in each trace with a result that a section in which information such as sub-code can be read and a section in which it cannot be read are dispersed on time axis. This enables the information to be obtained substantially in real time.

Abstract: A magnetic recording and reproducing device with an automatic tracking control function which can record and reproduce signals by means of a rotary head incorporating plural heads of different azimuth. The device performs tracking control by detecting, based on a timing of a synchronizing signal of a track, crosstalks of pilot signals obtained from adjacent tracks and comparing the crosstalks to use the difference as a tracking error signal. A form of the synchronizing signal is different alternately in a series of tracks of the same azimuth. The device comprises a designation element and a detection element for the synchronizing signal form.

Abstract: A clock signal reproducing circuit for a player reproducing information of a disc reproduces a clock signal from a signal reproduced from a disc via a pickup head.

Abstract: The rotation speed of a disc rotation motor is controlled such that a synchronizing signal derived from an output signal reproduced from a disc coincides with a reference oscillation frequency. The amount of data accumulated in a memory provided for absorbing jitter of the output signal reproduced from the disc is detected. In response to a result of the detection, a control signal in the disc rotation control is corrected such that the amount of data accumulated in the memory becomes substantially constant.

Abstract: An automatic focusing device in an optical type data reproducing apparatus is capable of restoring an objective lens to a position in which a servo controlling system can perform a normal servo control, when the servo controlling system has entered a divergent state. In the device, a photodetector produces a detection signal corresponding to a relative distance between the objective lens and a disk and, in response to this detection signal, the servo controlling system automatically controls the relative distance between the objective lens and the disk so as to form a focal point on a signal plane of the disk.