Canon Kabushiki Kaisha

Mitsuhiro Otokawa

Kenichi Nagasawa

Koji Takahashi

Hiroyuki Takimoto

Hiroo Edakubo

Keiji Satoh

Susumu Kozuki

Katsuji Yoshimura

Motokazu Kashida

Shinichi Yamashita

Masahide Hasegawa

Noritsugu Hirata

Hidetoshi Matsuoka

Yasuyuki Miyaoka

Shunpei Kimura

In an apparatus for recording an information signal on a recording medium forming many parallel tracks on the medium and for reproducing the information signal from the medium, a tracking control system is arranged to record a pilot signal of a given frequency along with the information signal in the first of the many tracks; to have the pilot signal also recorded in second and third tracks adjoining the first track on both sides thereof but at pilot signal phases shifted from the pilot signal phase of the first track to equal degrees in the directions opposite to each other at parts of the second and third tracks aligned perpendicularly to the longitudinal direction of the first track; and, in reproducing the information signal, the position of the recording medium and that of a reproducing head relative to each other are controlled on the basis of the pilot signal of the given frequency reproduced by the reproducing head from the first track along with the information signal.

Tracking control system using single frequency pilot signal

An apparatus for recording an input signal on a magneto-optical recording medium. The apparatus includes an optical head for applying a light beam to the medium, a circuit for delaying the input signal by a time for preventing a bit recorded on the medium from shifting relative to the input signal, a magnetic head for applying a magnetic field modulated in conformity with the delayed signal to that portion of the medium to which the light beam is applied, and a motor for moving the medium relative to the light beam.

Magneto-optical recording apparatus having means for delaying an input

A multi-channel recording apparatus in which n rotary heads (n is 3 or higher integer) are arranged on the outer peripheral edge of a drum is evenly spaced relation, and a tape-shaped recording medium is trained round the drum over an angular range of at least 360.degree..times.(1-1/n), while recording (n-1) channels of a signal on the recording medium by using the (n-1) of the n heads which are simultaneously tracing on the medium.

Recording apparatus for an information signal with a plural kinds of

There is disclosed a brushless motor provided with a speed detector for detecting the rotating speed of rotor; a synthesizer for synthesizing the output wave forms of inverse electromotive force of different phases of the brushless motor; a detector for detecting the synthesized wave form from the synthesizer; an inverter for inverting the detected wave form from the detector; an oscillator for generating a predetermined frequency; a frequency divider for dividing the frequency from the oscillator according to the output from the inverter; a counter for counting the clock output signal from the frequency divider, latching the count in a cycle of a signal from the speed detector and resetting the count; and a drive controller for generating a control voltage in response to the output from the counter thereby controlling the current supplied to the rotor.

Brushless motor with torque compensation

Tracking control system with pilot signal phase setting circuitry

A rotary head type reproducing apparatus wherein, three rotary heads are arranged to be capable of simultaneously tracing different parts of many parallel tracks formed on a record bearing medium, the parts differing from each other both in the transverse and longitudinal directions of the tracks; among the three heads, a first head is positioned in the middle part of each track in the direction of the width thereof; a first tracking error signal is formed to represent a level difference between pilot signals reproduced by the first head from second and third tracks adjoining both sides of a first track which is being traced by the first head; a second tracking error signal is formed to represent a level difference between pilot signals reproduced from the second and third tracks by second and third heads which are other than the first head; and tracking control is accomplished by using both the first and second tracking error signals.

Rotary head type reproducing apparatus with tracking control function

A multi-channel recording apparatus in which n rotary heads (n is 3 or higher integer) are arranged on the outer peripheral edge of a drum in evenly spaced relation, and a tape-shaped recording medium is trained round the drum over an angular range of at least 360.degree..times.(1-1/n), while recording (n-1) channels of a signal on the recording medium by using the (n-1) of the n heads which are simultaneously tracing on the medium.

Multi-channel recording apparatus using a plurality of heads in turn

A rotary head type recording apparatus according to the present invention can record information signals on a tape-shaped magnetic recording medium based on a plurality of kinds of recording modes in which track pitches are different from each other, and the track pitches of the recording tracks formed on the taped-shaped magnetic recording medium are varied depending on the kinds of the recording modes and at the same time a pattern of a signal-for-erasion supplied to a rotary type erasing head with wider width in the direction perpendicularly crossing a tracing direction of the head than that of a rotary type magnetic head is varied depending on the kinds of the recording modes, so that the undesirable influence of the signal-for-erasion over the recording of the information signals is reduced and at the same time power consumption is also reduced.

Rotary head type recording apparatus having an erasing function based on

A recording and reproducing apparatus in which track pitch is determined by using a signal reproduced by a rotary head which is also used for erasing.

Recording and reproducing apparatus with track pitch detection

An information signal recording apparatus having a rotary recording head and a rotary erase head is arranged to control timing for a start of recording by the recording head on the basis of the reproduction output of the rotary erase head.

Information signal recording apparatus

There is disclosed an information signal reproducing apparatus for reproducing information signals from a magnetic record bearing medium on which information signals are recorded with pilot signals of four different frequencies recurrently superimposed thereon. The apparatus comprises magnetic heads which are arranged to reproduce said information signals and said pilot signals by tracing said magnetic record bearing medium and an erasing head which is arranged to trace said magnetic record bearing medium in equal tracing direction to that of said magnetic heads and which is able to erase at least the information signals recorded on said magnetic record bearing medium and to reproduce said pilot signals. At the time of controlling a tracing position of said magnetic heads relative to said magnetic record bearing medium, four local pilot signals having the same frequencies as those of said pilot signals, respectively, are recurrently generated in a predetermined rotation. The state of said pilot signals reproduced by said magnetic heads is monitored, using said four local pilot signals and the tracing position on said medium of said magnetic heads is controlled, depending upon the state of said pilot signals. The level of a specific pilot signal from among said pilot signals reproduced by said erasing head is detected and the generating sequence of the local pilot signals is changed over, depending upon a result of such detention. According to such construction it is possible to effect the tracking control with high precision and high response speed.

Tracking control using signals reproduced by erase head

In an information signal recording and reproducing apparatus arranged to record in rotation pilot signals of a plurality of kinds having different frequencies, one in each of recording tracks along with an information signal on a recording medium and to reproduce the information signal from the recording medium, the relative positions of a rotary head which is reproducing the information signal and the recording medium are controlled by using the pilot signals reproduced by the rotary head and reference signals of a plurality of kinds which are of different frequencies corresponding respectively to the pilot signals of the plurality of kinds and are generated in rotation; and the generating sequence of these reference signals is changed by skipping a given number of reference signals according to signals reproduced by a rotary erase head during a reproducing operation.

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Kanagawa, Japan

Mitsuhiro Otokawa