JPS59178603A - Infomration recording or reproducing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an information recording or information reproducing device, and more particularly to a device that records different information on a plurality of tracks or individually reproduces information recorded on a plurality of tracks.

(Prior art) The above-mentioned device rotates a recording medium such as a magnetic disk or a magnetic sheet to form a plurality of concentric tracks, records video signals for one field on each track, and continuously records the video signals for one field. 1) A recording and reproducing apparatus that obtains a still image by reproducing the same will be explained as an example.

When recording a video signal in such a recording/playback device, in order to avoid overlapping recording of another video signal on a track where a video signal has already been recorded,
It is necessary to determine whether a video signal is recorded on the track. Such discrimination has conventionally been carried out by detecting an envelope recorded on a track using a magnetic head. Conventionally, the above t, envelope detection, and t are performed one by one by tracking the magnetic head used for envelope detection.

Therefore, in order to detect a track on which no video signal is recorded, time required for tracking and time required for the tracked magnetic head to settle into a stable state are required.

Therefore, there is a drawback that (2) it is not possible to immediately detect an empty track on a magnetic medium and record a video signal on that track.

(Objective) In view of the above-mentioned drawbacks, the present invention provides an information recording or information reproducing device that can quickly and accurately detect the presence or absence of information on each track while eliminating the above-mentioned drawbacks of the conventional example. The purpose is to

(Example) The present invention will be described below using examples. Furthermore, the citation of the following examples is not intended to limit the scope of the present invention.
The present invention can be modified within the scope of the claims.

FIG. 1 is a block diagram showing an embodiment in which the present invention is applied to a recording system of a recording/reproducing apparatus as described above. 1 in Figure 1
is a magnetic disk, and is constructed so that one field's worth of video signals is recorded on a circular recording track for each rotation of the magnetic disk. In the apparatus of this embodiment, nine such recording tracks are formed. 2 is a DC motor that rotates the magnetic disk 1 (3), 3 is a recording magnetic head that records video signals on the magnetic disk 1 as changes in magnetic flux, and 4 is a recording magnetic head that drives the recording magnetic head 3 to move onto each track. 5 is a step motor for driving the head feeding mechanism 4; 6 is a video signal input terminal; 7 is a modulator for modulating the input video signal; 8 is a step motor for driving the head transport mechanism 4; This is a recording amplifier that supplies a signal whose output is amplified to the recording magnetic head 3.

9 utilizes an element (hereinafter referred to as MR element) that converts the magnitude of a magnetic field into a resistance value, and is used as a magneto-electrical conversion element by connecting a constant current source to both ends of the element (
A multi-head (hereinafter referred to as MR head) is provided corresponding to each track formed on the magnetic disk 1 to detect the envelope of a signal recorded on each track. 10 is a constant current source that supplies current to the multi-head 9;
11 is a switch (4) for supplying the current output from the constant current source 10 to each track of the multi-head to each MR element; 12 is a selector switch 11 and a head feed switch; fff that controls the step motor 5 that drives the rocky shore
! The I control section 13 is an envelope detection section that detects envelope information obtained by the multihead 9 and transmits this information to the control section 12.

FIGS. 2(A), 2(B) and 2(C) are schematic diagrams of the multi-head 9 shown in FIG. 1. Figure 2 (A) is a top view of the multi-head 9, Figure 2 (B), , (C)
is a side view of the multi-head 9. In FIG. 2, 20 is an MR element that converts the magnetic field in each track on the magnetic disk 1 into a resistance value, and the M and R elements are installed in accordance with the position of each recording track on the magnetic disk 1, respectively. ing. Naturally, this multihead 9 has the same number of MR elements 20 as the number of tracks. 21 is an insulating layer that insulates each MR element 2o, and 22 is a current terminal for passing a current through the MR element 20. Note that l is equal to the track width on the magnetic disk 1.

In the configuration as described above, operation (5) will be explained below. When recording multiple video signals input to the video signal input terminal 6 onto tracks on the magnetic disk 1 using the recording magnetic head 6, a track on which no video signal is recorded is first detected and the recording magnetic head The head 3 must be moved to that track.

In this embodiment, the multi-head 9 is used to detect the unrecorded track described above. The envelope of the signal recorded on each track is detected by passing a constant current through each MR element 20 using the knob and changeover switch and detecting the voltage between each MR element. If a track where no envelope is detected is found, the control section 12 drives the step motor 5 to move the recording magnetic head 3 onto that track. Then, the video signal is recorded.

That is, when detecting the envelope recorded on the track, there is no need to track the magnetic head 3, and the MR element 20 detects the magnetic field due to the magnetization signal recorded on the track without rotating the magnetic disk (6) 1. can be detected, so the effort of rotating the magnetic disk 1 can be saved when searching for unrecorded tracks.

Further, since the signal output obtained from the MR transducer 20 is substantially greater than that obtained from an inductive reading type magnetic head, accurate information can be obtained.

In the above embodiment, the multi-head 9 is used to detect whether an envelope is recorded on a track, but the sensitivity of the MR element 20 can be adjusted by applying an appropriate bias magnetic field to each MR element 20. You can also raise it up and use it as a playhead.

FIG. 3 is a block diagram showing another embodiment of the present invention in which a multi-head is also used as a reproducing head. Third
In the drawings, the same numbers as in FIG. 1 refer to the same or equivalent parts as shown in FIG. In FIG. 3, reference numeral 14 denotes a regenerative amplifier that amplifies the envelope detection signal output from the envelope detection section 13.
5(7) is a reproduction signal processing circuit for obtaining a video signal from the output signal from the reproduction amplifier 14.

Figure 4 (Al l (B) l (C) is a schematic diagram of the multi-head 9' in Figure 3. Figure 4 (A) is a diagram of the multi-head 9' viewed from above; Figure (B), (
C) is a side view. In FIG. 4, the same numbers as in FIG. 2 indicate the same parts or equivalent parts, and the explanation thereof will be omitted. In FIG. 4, 23 is a conductor through which current flows in order to apply a bias magnetic field to the MR element. The magnetic field created by the current flowing through the conductor 23 serves as an appropriate bias magnetic field for the MR element 20, so that the MR element 20 is biased within its operating range. Can use multi-hera dog.

Further, the method of applying such a bias magnetic field to the MR element is not limited to the method of flowing a current and utilizing the magnetic field as described above, but may also apply a bias magnetic field using a permanent magnet.

Even in the embodiment (8) shown in FIGS. 3 and 4 described above, the same effects as in the embodiment shown in FIGS. 1 and 2 can be obtained. Furthermore, by using the multi-head 9' as a means for reproducing video signals, it is possible to eliminate the trouble of tracking the reproducing head as in the prior art when reproducing video signals. Therefore, the video signal can be reproduced immediately after the command is issued.

(Effect) As explained above using the examples, according to the claimed invention,
To obtain an information recording or information reproducing device capable of quickly and accurately detecting the presence or absence of information on each track.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing one embodiment of the present invention, Fig. 2 (A), (B) l (C) is a schematic diagram of the multi-head shown in Fig. 1, and Fig. 3 is a block diagram showing an embodiment of the present invention. A block diagram showing the embodiment. FIGS. 4(A), 4(B), and 4(C) are schematic diagrams of the multi-herald (9) shown in FIG. 3. 1... Magnetic disk 3... Recording head 4... Head feeding mechanism 9... Multi head 10... Constant current source 11... Changeover switch 13... Envelope detection unit 20... # MR element 21 ... Insulating layer 22 ... Current terminal of each MR element 20 Applicant: Canon Co., Ltd. (10)

Claims (1)

[Claims] (1) A device that records different information on each of a plurality of tracks or reproduces information recorded on a plurality of tracks individually, including a magneto-resistive conversion element arranged corresponding to each track, An information recording or information reproducing device comprising means for detecting the presence or absence of information on a track.