JPS62146409A - Magnetic recording device - Google Patents

Abstract

PURPOSE:To reduce the quantity of noise generated in a reproduced output by using a single gap head as a magnetic head when data are to be recorded and reproduced by sliding the magnetic head on a rotary magnetic recording medium having <=63.5 tracks/inch track pitch, and regulating track width to a specific value. CONSTITUTION:Data are recorded and reproduced by sliding the magnetic head on the magnetic recording medium having <=63.5 tracks/inch track pitch as follows. Namely, the single gap head including all functions for data writing, reading and reproducing is used as the head and the track width is specified so as to be the same value as the track pitch or a range of +0 and -50mum. In said constitution, an unerased part is not simultaneously reproduced at the reproducing of a required track, so that the level of significance for the generation of data errors is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording device that records and reproduces data on and from a rotationally driven magnetic recording medium using a magnetic head.

[Summary of the invention]

The present invention is a magnetic recording device that rotationally drives a magnetic recording medium, and by widening the track width of the ventilation head used therein to the same extent as a track pinch, recording, reproducing, and erasing can be performed using an inexpensive single gap head. Although it has all the functions, it is designed to ensure data error reliability against off-track phenomena caused by the environment, device manufacturing parameters, etc.

[Prior art]

2. Description of the Related Art Conventionally, there are roughly two types of magnetic heads used in disk-type magnetic recording devices, particularly flexible disk drives, which drive a magnetic recording medium in full rotation. The magnetic head used in high-end drives is a combination head that integrates a recording/reproducing gap and an erase gap. The magnetic head for general drives was a single-gap head for recording, reproducing, and erasing. The track width of this single gap hend is sufficiently small compared to the track pinch, and even if off-track, the adjacent track is not read out, so the unrecorded card band is fully used.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional technology, the combination head has a complicated structure as shown in FIG.
It is necessary to make the relative position t between the playback head and the erase hand highly accurate. This makes manufacturing the magnetic head difficult. Also, special timing must be taken for recording and erasing in terms of circuitry. When using the other single gap hend, an unrecorded guard band 55 is provided to prevent crosstalk from adjacent tracks, as shown in FIG. However, the unerased portion of the own track due to off-track, 34, always occurs.
There is a high possibility that the head will be located at a position that simultaneously constitutes the unerased portion.

In this case, there is a problem in that when the unerased portion 54 exceeds a certain amount, that is, when the amount of noise superimposed on the reproduced output increases, a read error occurs.

In order to completely solve this problem, JP-A-60-79'505
A method of performing full optical erase and then writing is also considered, but this method imposes restrictions on the host computer and requires special functions such as being equipped with RAM memory.

The present invention is intended to solve all of these problems, and its purpose is to suppress the noise superimposed on the reproduced output to 1t20 dB or less.

[Means to solve the problem]

The magnetic recording device of the present invention is characterized in that the track pinch is a coarse pinch of 6×5 tracks/inch or less, and the track width of the magnetic head used therein is approximately the same as the track pinch.

[For production]

According to the above structure of this patent, the track pinch is 400
Since the magnetic head track width is as wide as μm or more, and the magnetic head track width is about the same, depending on environmental conditions such as temperature and humidity, and drive manufacturing variations, the track position may be 10% wider than the previously recorded track position.
Even if the position is shifted and re-recorded, and the readout is performed at the original track position during playback, an 8/N ratio of 20 dBi can be ensured, ensuring data reliability as long as the off-track is within the above level. can.

[Example 1] FIG. 4 shows the state of the recording pattern in the present invention. This means that the recording track width is approximately 50 μm for track pinch.
This is a narrow method. This type emphasizes the reliability of self-scythe recovery rather than compatibility with other machines. track 1,
Track 2 and track 5 are track patterns recorded initially. There are about 50 tracks between the track patterns.
A guard band 47 at μtn is generated. First, consider the cost of reproducing this recorded data. When recording and reproducing on the own device, under certain circumstances, no off-track occurs and the magnetic head traces over the track pattern, so no problems occur. However, if the environment changes, such as when the recording temperature is low and the reproduction temperature is high, or vice versa, or if the humidity environment changes, the magnetic head may trace a track pattern that deviates from the previously recorded track pattern. Put it away. This fL is an off-track phenomenon. In this case, since there is a guard band 47, there is no danger of reading adjacent tracks at the same time until the off-track amount is about 50 μm, and since the track pinch is 63.5 tracks/inch, the track width is also about 400 μm, and there is a sufficient magnetic head. Once output is obtained, production is possible.

Let's consider what will happen if some of the data is stored in the next case. A part of track 2 was rewritten to become track 2'. At this time, it is assumed that due to the above-mentioned change in environmental conditions, the data was off-track and re-recorded. As a result, an unerased portion 48 is generated.

Furthermore, assuming that the environmental conditions when this data was played back were the same as when the initial data was recorded, then when tracks 2 and 2' are played back, the erased portion 48 is also played back while the track 2' portion is being read. Resulting in. This unerased portion is superimposed on the reproduction head output of track 2' as a noise component, so if its amount becomes large, a data error will occur. When the s/h+ level of the head output at which data errors occur was measured, it was found that up to about 20 dB could be reproduced without errors. In other words, reproduction is possible if (unerased portion)/(data portion)≦9 within the read track width. In the case of this patent, since the track width is assumed to be 400 μm or more, an off-track amount of 40 μm or more is allowable.

[Embodiment 2] It was stated at the end of Embodiment 1 that the wider the track width, the more advantageous the amount of off-track when re-recording is performed. In the future, we will focus on considering compatibility with other machines of the same type, which is a characteristic of flexible disk drives. In this case, a magnetic head having a track width equivalent to that of the track pinch is used. The entire recording pattern diagram in that case is shown in FIG.

All conditions that cause off-track, occurrence of unerased areas, and read conditions that tend to cause data errors are all implemented.
Since it is the same as J+, the explanation will be omitted.

Since there is no guard band, there is a problem that adjacent tracks are always played back at the same time due to the off-track when reading from the initial recording, but since the recording track width is wide, there is a problem that the erased residue that occurs when re-recording occurs. The smaller the ratio with respect to 9, the less likely reproduction errors will occur. It should be noted that the wider the track pinch, the better.However, if the track pinch is the same, recording performance will drop, so it is not good to make it too wide.

〔Effect of the invention〕

According to the above-described invention, even though a single gamble hand is used, the risk of reproduced data errors, which is a problem with this type, can be reduced. Furthermore, if the risk of data errors is taken into consideration, the combination head shown in FIG. 2 is preferable, but the head used in the present invention shown in FIG. 6 also has the advantage of being about half the cost.

[Brief explanation of drawings]

FIG. 1 is a track pattern diagram according to the present invention. The second problem is the bottom view of a conventional magnetic head. FIG. 5 is a diagram of a conventional recording pattern. FIG. 4 and FIG. 5 are recording pattern diagrams in an embodiment according to the present invention. FIG. 6 is a bottom view of the magnetic head used in the present invention. Applicant: Seiko Epson Co., Ltd. +I H1 board/Citra 1,77/gutter Figure 1, Figure 22 Read/Write 1,000/-/No I-Raise 4 to 3,7 , cannon, meen 2nd figure follower>gu: legi ¥...7fu"% l-/) '2 death meeting pattern country 3rd figure @self-money right tiger 5,7fligter> Dro Figure 4 ↓ Dead Record Tora, 7 Kupatan Figure 5

Claims (1)

[Claims] In an apparatus that records and reproduces data on a rotationally driven magnetic recording medium using a magnetic head and has a track pitch of 63.5 tracks/inch or less, the magnetic head performs all functions of writing, reading, and reproducing data. The track width is as follows:
Same as track pitch, or ▲mathematical formula, chemical formula,
A magnetic recording device characterized by having values in the range of ▼.