JPH02306402A - Recording/reproducing circuit for flexible disk device - Google Patents

Abstract

PURPOSE:To obtain the same electrical characteristic with use of the heads of the same electrical characteristic at both sides '0' and '1' by securing the different actions of the correction circuits contained in the recording circuits with each head. CONSTITUTION:A recording/reproducing circuit of a flexible disk device consists of a read/write head 1, a preamplifier 2, an LPF 3, a differentiator 4, a comparator 5, a system 6, a side '0' recording circuit 11, and a side '1' recording circuit 12. The recording circuit is divided into two parts. That is, the circuit 11 works when a selection signal 10 for side '0' and '1' selects a head of the side '0'. While the circuit 12 works when the signal 10 selects a head of the side '1'. Then the errors of the reproduction output and the characteristic caused by a mechanical error between both heads are corrected. Thus the same standard is secured for both heads between both sides '0' and '1'.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a circuit configuration that equalizes the different electrical characteristics of each head on sides "0" and "1.1" in a flexible disk device (FDD). be.

[Prior Art] FIG. 5 is a block diagram showing the circuit configuration of a recording/reproducing circuit of a conventional flexible disk device.

In the figure, 1 is a read/write head, 2 is a preamplifier, and 3
4 is a low-pass filter (LPF), 4 is a differentiator, 5 is a comparator, 6 is a system for connecting a flexible disk device, 7 is a step pulse signal, 8 is a track counter, 9 is a correction signal, and 20 is a recording circuit.

Figures 6(a) and (b) show the track-to-playback output characteristics and track-to-resolution characteristics when using J\rad with the same electrical characteristics in the recording/playback circuit of the flexible disk device shown in Figure 5. FIG. In the figure, 2
1 is the track vs. playback output 9 resolution characteristic of the head on side "0", 22 is the track vs. playback output 9 resolution characteristic of the head on side "1", and 23 is each of sites "0" and "1" on the same track. The difference in the playback output of the head, 24, is the difference in the playback output of the side 'OJ l' I on the same track.
It shows the difference in resolution of each head of J.

FIG. 7 is a distribution diagram showing the resolution of each head on sides rQJ and rlJ in the recording/reproducing circuit of the flexible disk device shown in FIG. In the figure, 13 is the average resolution of the head on the side "0" side, 14 is the average resolution of the head on the side "1" side, 15 is the lower limit of resolution at which the head becomes defective, and 16 is the head resolution 25 is the defective area of the head on side "0" which exceeds the upper limit of resolution 16, and 26 is the defective area of the head on side "1" which is below the lower limit of resolution 15. It shows.

Next, the operation of the recording/reproducing circuit of the above-mentioned conventional flexible disk device will be explained. In a flexible disk device, in order to record the same amount of data per track regardless of whether it is on the inner or outer side of a recording medium (not shown), the recording density must be higher on the inner side of the recording medium. Therefore, both the reproduction output and the resolution deteriorate, as shown in the track versus reproduction output characteristic shown in FIG. 6(a) and the track versus resolution characteristic shown in FIG. 6<b>.

Therefore, in a recording/reproducing circuit adapted to the outer circumference of the recording medium, the resolution of the inner circumference of the recording medium becomes too low, resulting in a reduction in the read margin.

In addition, in a recording/playback circuit that is adapted to the inner circumference of the recording medium, the resolution of the outer circumference of the recording medium becomes too high, and when data is overwritten, the previous data cannot be erased and errors occur. Data is read out. Therefore, record
In a reproducing circuit, contradictory requirements are required: the resolution should not be too high on the outer circumference side of the recording medium, and the resolution should not be too low on the inner circumference side of the recording medium.

In order to satisfy such requirements, the recording/reproducing circuit counts step pulse signals 7 from the system 6 side with a track counter 8 as shown in FIG. ), that is, the position of the track on the recording medium, the track counter 8 outputs a correction signal 9 at the detected track, and the rival filter 3. Differentiator 4. When the correction circuit in the recording circuit 20 is operated and the head is located on the inner circumference side of the recording medium, a recording/reproduction circuit tailored to the inner circumference side is used, and the head is placed on the outer circumference side of the recording medium. When it is located, a recording/playback circuit tailored to the outer circumference is used.

By the way, the side rQJ of the flexible disk device,
In the structure of each head of rlJ, the head on side "1" is located on the inner circumferential side of the recording medium compared to the head on side "0", and is shifted by 4 or 8 tracks. Therefore, even if heads with the same electrical characteristics are used on both sides, the difference in the track position of each head on sides "0" and "1" is the difference in the electrical characteristics of each head on sides "0" and "1". characteristics are different, conventional side rOJ,
In a recording/reproducing circuit without a correction circuit for each rlJ head, it is extremely difficult to make the electrical characteristics of the side rQJ and rlJ heads equal. That is,
As shown in FIG. 7, the average value 13 of the J\rad resolution on the side "0" side is larger than the average value 14 of the resolution of the head on the side "1" side, and the electrical characteristics of the conventional recording/reproducing circuit Side “0” from the resolution range that satisfies
In the head on the side, the defective area 25 of the high-resolution head is
Further, in the heads on the side "1", head defects occur in the defective regions 26 of the heads with low resolution.

In order to solve the occurrence of such head defects, we changed the specifications of each head on side "0" and "1",
The specifications of each head were changed.

However, the switching of the correction circuit in the recording circuit 20 depends entirely on the position of the track, and the switching of the correction circuit in the recording circuit 20 depends entirely on the position of the track, and the switching of the correction circuit in the recording circuit 20 depends entirely on the position of the track.

Since the position of each head "1" is fixed, even if heads with the same electrical characteristics are used on both sides, it is not possible to obtain the same electrical characteristics as a flexible disk device.

[Problems to be Solved by the Invention] Since the recording/reproducing circuit of the conventional flexible disk device is configured as described above, the side "0",
Since it is not possible to correct the mechanical deviation of each head of "1" with the recording/reproducing circuit, the specifications of each head on both sides have to be narrowed, or side ro", rl, , +
As a result, the yield of heads deteriorates, and
There was a problem with raising the boss of the head. Furthermore, since the electrical characteristics of the flexible disk device differ between the heads on the "0" and "1" sides, there are other problems, such as the fact that only unreliable products can be obtained.

This invention was made to solve the above-mentioned problems.If the heads on sides "0" and "1" have the same electrical characteristics, the flexible disk device can have the same electrical characteristics. Show and also side ro'', RL
.

[Means for Solving the Problems] A recording/reproducing circuit of a flexible disk device according to the present invention includes a side "0" recording circuit that operates when the side "0" head is selected, and a side "0" recording circuit that operates when the side "0" head is selected. It is equipped with two recording circuits, a side "1" recording circuit, which is operated when the head is selected, and the side "0" recording circuit and the side "1" recording circuit supply a write current to the recording medium to the sides l"roj, rl'' is uniformly changed according to each head.

[Function] The recording/reproducing circuit of the flexible disk device according to the present invention has a side “0” head for a side “0” head.
The operation of the correction circuit in the recording circuit and the operation of the correction circuit in the side "1" recording circuit for the head on side "1" are different for each head on sides rQJ and rl, and as a result, (1) Differences in electrical characteristics of the flexible disk device due to mechanical positional deviation of the heads on sides "0" and "1" can be corrected and the same electrical characteristics can be provided.

(2) The specifications of the heads on sides "0" and "1" can be made the same, and the specifications of each head can be widened.

(3) Since the reproduction characteristics of the side rOJ and rlJ heads are the same, the reproduction circuit can be optimized.

[Embodiment] FIG. 1 is a block diagram showing the circuit configuration of a recording/reproducing circuit of a flexible disk device according to an embodiment of the present invention.
The same reference numerals as in the conventional example shown in FIG. 5 above indicate the same or corresponding parts, and detailed explanation thereof will be omitted. In the figure, 10 is a side "0", "1" select signal for selecting each head of the side "OJ, rlJ", 11
12 is a side "0" recording circuit when the side "0" head is selected, and 12 is a side "1" recording circuit when the side "1" head is selected.

Figures 2 (a) and (b) show track-to-reproduction output characteristics and track-to-resolution characteristics when heads with the same electrical characteristics are used in the recording/reproducing circuit of the flexible disk device shown in Figure 1. 3 is a distribution diagram showing the resolution of each head on side "0" and "l" in the recording/reproducing circuit of the flexible disk device shown in FIG.
FIGS. 4(a) and 4(b) are diagrams showing write current versus playback output characteristics and write current versus resolution characteristics in the recording/playback circuit of the flexible disk device of FIG. 1.

In FIG. 3, 13 indicates the average resolution of the head on side "0", and 14 indicates the average resolution of the head on side "l". Further, in FIGS. 4(a) and (I), 17 is the write current of each head on the conventional site rOJ and rlJ side, 18 is the write current of the head on the side "0" side of the present invention, and 19 is the write current of the head on the side "0" side of the present invention. side “1”
The write current of the side head is shown.

Next, the operation of the recording/reproducing circuit of the flexible disk device according to the embodiment of the present invention will be explained. The defective head in the conventional example shown in FIG.
As shown in the figure, the defect occurs in the high-resolution head area 25 on the head on the site "0" side, and on the side "1"
On the side head, the problem occurs in the defective area 26 of the head with low lO- resolution. this is,
As shown in FIGS. 4(a) and (b), the conventional side "0"
", since the write current 17 of each head on the "1" side is the same, the mechanical misalignment of each head on sides rQJ and rlJ causes side "0".

Appropriate recording/reproducing circuits cannot be used for each "1" head.

On the other hand, in the recording/reproducing circuit according to the present invention, the recording circuit is divided into two as shown in FIG. When selecting the head, press the side “O”
” The recording circuit 11 is operated, and when the side “1” head is selected, the side “1” recording circuit 12 is operated.

Therefore, the write current of each head on the side 'OJI'IJ side is 17% compared to the write current of each head on the side 'OJI'IJ side, as shown in FIGS. 4(a) and (b). , the write current 18 of the head on the side "oj" side is large, and the write current 19 of the head on the side "1" side is small. Difference 23 in the playback output of heads on sides “o” and “1” on the same track as shown in b), and difference 24 in resolution between heads on sides “0” and “1” on the same track
are respectively corrected, and as a result, Fig. 2(a) and (
As shown in b), the track vs. playback output characteristics and the track vs. resolution characteristics have the same electrical characteristics for each head on side "0" and "1", and as shown in Figure 3, The distribution of resolution for each head on the OJ and rl sides is also the same, and the average values are also the same.In this way, the distribution of resolution is the same for each head on the side job and rlJ sides, so the reproducing circuit is It becomes possible to design a circuit suitable for the distribution, and as a result, the number of defective heads can be reduced.

[Effects of the Invention] As described above, the recording/reproducing circuit of the flexible disk device of the present invention has a side "0" recording circuit that operates when the head of the side rOJ is selected;
It is equipped with two recording circuits, a side rlJ recording circuit that is activated when the side "1" head is selected, and the side rOJ recording circuit and the side "l" recording circuit transfer the write current to the recording medium to the side "0" head. , "1", so that the deviation in the playback output characteristics due to the mechanical deviation of the side roJ and rlJ heads can be corrected, and the specifications of each head can be adjusted to the side "0". '' and ``1'' side, it is possible to reduce the number of defective heads in this type of conventional reproduction circuit, and it is possible to make the electrical characteristics of each head the same, making the product cheaper. This provides an excellent effect in that a highly reliable flexible disk device can be produced.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the circuit configuration of a recording/reproducing circuit of a flexible disk device according to an embodiment of the present invention, and FIGS. 2(a, 2) and (b) are recording/reproducing circuits of the flexible disk device of FIG. Figure 3 shows the track vs. playback output characteristics and track vs. resolution characteristics when heads with the same electrical characteristics are used in the circuit. Distribution diagrams showing the resolution of each head on the OJ and rl+ side, Figures 4 (a) and (b) show the write current vs. playback output characteristics and the write current vs. FIG. 5 is a block diagram showing the circuit configuration of the recording/reproducing circuit of a conventional flexible disk device, and FIGS. 6(a) and (b) are diagrams showing resolution characteristics.
) is a diagram showing track vs. playback output characteristics and track vs. resolution characteristics when heads with the same electrical characteristics are used in the recording/reproducing circuit of the flexible disk device shown in FIG. 5, and FIG. In the recording/playback circuit of a flexible disk device, side "0". FIG. 7 is a distribution diagram showing the resolution of each head on the “1” side. In the figure, 1... read/write head, 2... preamplifier, 3... low pass filter (LPF), 4...
Differentiator, 5... Comparator, 6... System, 7
...Step pulse signal, 8...Track counter, 9...Correction signal, 10...Side rQJ, r
lJ select signal, 11...site "0" recording circuit,
12... Side "1" recording circuit, 13... Side "
Average resolution of the head on the 0" side, 14...Side "
1" average value of the resolution of the head on the side, 15...lower limit of resolution that causes head failure, 16...upper limit of resolution that causes head failure, 17...conventional side job,
Write current of each head on rlJ side, 18... Write current of head on side "0" side of this invention, 19...
・The writing current of the head on the side “1” side of this invention, 2
0... Recording circuit, 21... Track vs. playback output 5 resolution characteristics of the head on side "0", 22... Side "0"
1” head track versus playback output 9 resolution characteristics, 23
...Side rOJ, rl in the same track
”, 24... Difference in resolution of each head on sides rQJ and rlJ on the same track, 25... Defective area of head on side "0" side, 26... Side This is the defective area of the head on the "1" side. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] In the recording/playback circuit of flexible disk devices,
The recording circuit is divided into a side "0" recording circuit that operates when the side "0" head is selected, and a side "0" recording circuit that operates when the side "0" head is selected.
The write current to the recording medium of each of the side "0" recording circuit and the side "1" recording circuit is divided into two, and the side "1" recording circuit is operated when the head "1" is selected. A recording/reproducing circuit for a flexible disk device, characterized in that the recording/reproducing circuit for a flexible disk device is provided with a means for uniformly changing the output voltage according to the head on the side "0" and the head on the side "1".