JPH0721847B2 - Head output adjusting device for rotary head type recording / reproducing apparatus - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a VTR (video tape recorder) and a DAT.
The present invention relates to a head output adjusting device for a rotary head type recording / reproducing device such as a (digital audio tape recorder).

[Conventional technology]

FIG. 5 is a perspective view showing a general configuration of an output adjusting device of a conventional rotary head type recording / reproducing device. In the figure, 1 is a supply reel, 2 is a take-up reel, 3a to 3f are magnetic tape running guides, 4 is a tape tension control guide, 5a and 5b are guide rollers, 6a and 6b are slide guides, 7 is a rotary drum, 8
Is a head mounted on the rotating drum 7, 9 is a tape guide lead provided on a fixed drum, 10 is an erasing head arranged between the tape tension control guide 4 and the guide roller 5a,
Reference numeral 11 is, for example, a fixed head for tape speed control, 12 is a capstan shaft, 13 is a pinch roller, and 14 is a cassette in which the tape 104 is stored.

FIG. 6 is a view showing a part of a conventional head wrapping tape. In the figure, 104 is a tape, 105 is a tape 104
Is an abrasive part in which an abrasive is applied to the entire surface of.

FIG. 7 is a perspective view of the head 8. 16 is a head gap, 17 is a glass portion, 18 is a sliding surface, 19 is a head curvature Ry in the sliding width direction, and 20 is a head curvature Rx in the sliding length direction. Show.

FIG. 8 is a view specifically showing the curvature of the head 8, FIG. 8 (a) is a plan view, and FIG. 8 (b) is a side view. In both of FIGS. 8 (a) and 8, the reference numeral 21 indicates the initial state before polishing, and the reference numeral 22 indicates the state in which the tape 105 has been fit to the ground state.

FIGS. 9 (a) to 9 (d) are views showing a reproduction state, in which 23 shows a good reproduction waveform, and 24 shows a reproduction waveform before polishing in which the tape and the head are not properly matched, for example, The front falling phenomenon 25 in FIG. 2 (a), the middle falling phenomenon 26 in FIG. 2 (b),
FIG. 9 (c) shows the post-fall phenomenon 27, and FIG. 9 (d) shows the output level small 28.

In FIG. 9A, reference numeral 106 indicates the head and tape writing start, 107 the middle of writing, and 108 the head and tape writing end. FIG. 10 shows a flow chart showing the head output adjusting step.

Next, the operation will be described. The head 8 obliquely repeatedly slides and scans the surface of the tape 104 for head wrapping shown in FIG. At this time, the head 8 is polished by the abrasive part 105 applied to the surface of the tape 104. Then, the head curvature 21 before polishing shown in FIG. 7, FIG. 8A, and FIG. 8B gradually becomes the head curvature 22 after polishing, which is familiar to the tape 104.

In the reproducing state, as shown in FIGS. 9 (a) to 9 (d), in the reproduced waveform, the front falling phenomenon and the middle falling phenomenon,
Polishing was applied to the initial state that shows a phenomenon such as a post-fall phenomenon or a small output level to obtain a good interface that is familiar between the head and the tape.
A good rectangular playback waveform 23 is obtained.

Conventionally, this head output adjusting step is performed by the method shown in FIG. 10, for example, and the rotary drum 7 is mounted in step S1 in the system shown in FIG. 5 and a wrapping tape is used (step S2) or set time (step S2). Wrap for 10 seconds, for example (step S3) and replace with normal tape (step S3)
4) In step S5, the reproduced waveform is visually inspected, and if it is good, the head output adjustment is finished in step S6, but if it is insufficient, in step S7, the wrapping tape is used again for a certain set time (for example, After lapping for 5 seconds (step S8), the reproduction output state of the normal tape is inspected in step S9 (step S10).

If it is still insufficient, the rotating drum is defective and the rotating drum is replaced (step S11), and this routine is repeated.

[Problems to be solved by the invention]

In the conventional head lapping method as described above, it is unclear how much the head has been polished, and there is a problem that the tape must be replaced each time the determination is made and that the head life is shortened due to excessive polishing. .

The present invention has been made to solve the above problems, and a head of a rotary head type recording / reproducing apparatus capable of performing polishing while judging the polishing state by monitoring the reproduction output level and polishing simultaneously. The purpose is to obtain an output adjusting device.

[Means for solving problems]

A head output adjusting device for a head-type recording / reproducing device according to the present invention is a tape having a part coated with a polishing agent to serve as a polishing part and a magnetic part having a predetermined signal recorded in another part. When the head is polished with this tape, a discriminating means for judging the state of head polishing is provided.

[Work]

In the present invention, when the head is polished with a tape having a magnetic material portion on which a signal is recorded in advance and an abrasive material portion, when the head passes through the magnetic material portion of the tape, the reproduction output of the signal read by the head The discriminating means discriminates whether or not the level has reached a predetermined set level, and the polishing is completed in the shortest polishing time.

〔Example〕

An embodiment of the rotary head type recording / reproducing apparatus of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment. In FIG. 1, a head 8 is mounted on the rotary drum 7 in a state where the rotary drum 7 is mounted on a tape traveling system (not shown), and 9 is a tape guide formed on the outer peripheral surface of the rotary drum 7. For leads,
104 is the tape for wrapping shown in FIG.

As shown in FIG. 2 (plan view), the lapping tape 104 is provided with an abrasive portion 105 by applying an abrasive to the substantially central portion in the longitudinal direction.
Adjacent to 05, there is provided a reproduction track section 103 of a magnetic material section in which a signal is recorded in advance.

Linear track portions 101 are provided on the outer peripheral sides of the abrasive portion 105 and the reproduction track portion 103, respectively, with a guard band portion 102 interposed therebetween.

Here, the explanation is returned to FIG. Reference numeral 30 in FIG. 1 denotes an amplifier, which amplifies the reproduction output reproduced by the head 8 and sends it to the sequence circuit unit 15. The sequence circuit section 15 is shown as a flow chart showing the flow of the operation in order to explain its operation.

Next, the operation will be described. As shown in FIG. 1, when the rotary head type recording / reproducing apparatus is assembled, the rotary drum 7 is mounted on the tape running system (not shown), and the tape 10
In order to make the head 4 compatible with the head 4, the head 8 is polished by using the lapping tape 104 shown in FIG. 2, for example.

The head 8 scans the tape in an oblique direction. Therefore, the head 8 is gradually polished as the head 8 repeatedly scans the reproducing track portion 103 and the abrasive portion 105.

The signal detected when the head 8 scans the recorded reproduction track 103 is the sequence circuit shown in FIG.
Then, the head output is sent to the sequence circuit 15 in step S21, the reproduction output level is detected in step S22, and it is determined in the next step S23 whether the reproduction output level has reached a predetermined set level.

When the favorable reproduction output level is reached in step S24, the head polishing is automatically stopped and the head output adjustment is finished.

If the reproduction output level has not reached the set level in step S23, the steps S21 to S23 are repeated by the step of continuing polishing in step S25.

In the above embodiment, the determination is automatically performed in the sequence, but the reproduction output level may be determined visually.

Further, if the image can be judged by VTR such as VTR, the reproduced image may be displayed on the monitor for judgment.

Further, in the above embodiment, the upper half of the tape width is not limited to the abrasive portion 105 and the lower half is the magnetic material portion, that is, the reproduction track portion 103 as shown in FIG. As shown in FIG.
The upper and lower sides of the tape may be the reproduction track portion 103 that is a magnetic material portion, and may be a tape having both a magnetic material portion and an abrasive portion.

Further, in the above embodiment, the tape having both the magnetic material portion and the abrasive portion has been described, but an abrasive is added to the magnetic material portion itself to make the abrasiveness of the entire tape as the magnetic material / polishing portion 109. An elevated tape such as FIG. 4 may be used. The tape may be mounted in a cassette before use.

〔The invention's effect〕

As described above, according to the present invention, the head output adjusting device of the rotary head type recording / reproducing device is provided with the judging means for judging the head polishing condition, and the reproducing output is detected at the same time when the head is polished by the tape. Therefore, the head life can be prevented from being shortened due to over-polishing during head lapping, while the labor of re-polishing due to insufficient polishing and tape replacement can be saved, and an optimum state can be obtained very easily.

[Brief description of drawings]

FIG. 1 is a block diagram of a head output adjusting device of a rotary head type recording / reproducing apparatus according to an embodiment of the present invention, and FIGS. 2 to 4 are plan views showing a head wrapping tape used in the same embodiment. FIG. 5 is a perspective view showing a configuration of an output adjusting device of a conventional rotary head type recording / reproducing apparatus, FIG. 6 is a plan view of a conventional head lapping tape, and FIG. 7 is a conventional rotary head type recording / reproducing apparatus. 8A is a perspective view of a head used in the output adjusting device of FIG. 8, FIG. 8A is a plan view specifically showing the curvature of the tip of the head of FIG. 7, and FIG. 8B is FIG. 8A. ) Side views, FIGS. 9 (a) to 9 (d) are diagrams showing reproduction waveforms by the output adjusting device of the conventional rotary head type recording / reproducing device, and FIG. 10 is a conventional rotary head type recording / reproducing device. Showing the head output adjustment process by the output adjustment device A chart. 7 ... Rotating drum, 8 ... Head, 15 ... Sequence circuit section, 103 ... Playback track section, 104 ... Tape, 105 ...
… Abrasive part. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (5)

[Claims] 1. A drum equipped with a rotary head is attached to a device,
In the head output adjusting device of the rotary head type recording / reproducing device, the head surface in the vicinity of the head gap is polished so as to have an optimum interface with the magnetic tape by using a lapping tape to obtain a stable head output. The lapping tape is provided with a reproduction track portion in which a predetermined signal is recorded in advance and an abrasive portion for polishing the head, and the reproduction output level of the reproduction track portion reproduced by the head is detected and compared with a set level. Then, a head output adjusting device for a rotary head type recording / reproducing device is provided, which is provided with a discriminating means for discriminating whether or not the head polishing should be continued based on the detected level. 2. The lapping tape comprises a magnetic material portion capable of magnetic recording and reproduction and an abrasive portion coated with an abrasive for head cleaning, which are separately provided. A head output adjusting device for a rotary head type recording / reproducing device according to the item. 3. A head output adjusting device for a rotary head type recording / reproducing apparatus according to claim 1, wherein the lapping tape has a magnetic material capable of magnetic recording / reproducing with an abrasive. . 4. The head output adjustment of the rotary head type recording / reproducing apparatus according to claim 1, wherein the determining means uses a sequence circuit to automatically determine whether or not head polishing should be continued. apparatus. 5. The output adjusting device for a rotary head type recording / reproducing apparatus according to claim 1, wherein the discriminating means displays the head reproduced output as a reproduced image on a monitor.