JPH03122811A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To contrive high recording densification by setting a parameter value to be obtained from an angle formed with a tangential line at an apex part of a sliding surface and a tangential line in an end part position and an inflow angle of a recording medium and also tension per unit width of the medium to fall within a prescribed range. CONSTITUTION:The angle formed by the tangential line Ls in the end part position of the sliding surface 3 of a magnetic head 1 and the tangential line Lo in the apex part position forming a magnetic gap 4 is denoted as alpha, and the angle formed by the magnetic tape 2 in its inflow/outflow direction to the sliding surface 3 and the tangential line Lo is denoted as beta, and then the tape tension per unit width of the magnetic tape 2 is denoted as T. The parameter P is specified as P=TXsin(beta-alpha), and this parameter value is constituted to fall within a range from 0.12gf/mm to 0.3gf/mm. The constitution is established by changing the relationship of alpha and beta in order to compensate an increasing amt. of this tension, so that the traveling with the smallest possible space can be maintained. By this method, excellent electromagnetic conversion characteristics at the time of high speed traveling can be maintained, and hence high recording densification can be contrived.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording/reproducing device, and more specifically, a magnetic recording medium such as a cassette streamer is made to travel back and forth at high speed, thereby achieving a large storage capacity. The present invention relates to a magnetic recording/reproducing device that aims to achieve high speed and high recording density.

[Conventional technology]

For example, in a magnetic recording and reproducing apparatus that performs magnetic δCC replay on a magnetic tape, as shown in FIG. A magnetic gap 23 is provided approximately at the center of this sliding surface 22. Then, the guide roller 24
A magnetic tape 25 guided by 24 runs while sliding on the sliding surface 22. By the way, the contact range of the magnetic tape 25 on the sliding surface 22 is the same as that of each guide roller 24.
- It varies depending on the positional relationship between 24 and the sliding surface 22. In the case of the first conventional example shown in the figure, the magnetic tape 25
do not wrap around the entire width of the sliding surface 22, but are in contact only within a region i on the center side within the sliding surface 22. With this configuration, when the magnetic tape 25 is run at high speed in the direction indicated by arrow R in the figure, a gap (hereinafter referred to as
(called spacing). The spacing distribution in this case varies greatly across the position of the magnetic gap 23, as shown in FIG. In a configuration that produces such a spacing distribution, the spacing on the magnetic gap 23 changes due to disturbances such as vibrations, and therefore, as this spacing increases, output loss increases. It is not possible to stably record short wavelengths.

Therefore, for example, in the device described in Japanese Unexamined Patent Publication No. 60-124052 (hereinafter referred to as the second conventional example), as shown in FIG. , that is, the chordal direction and the sliding surface 32
The angle β formed between the chord direction and the inflow direction of the magnetic tape 34 (hereinafter referred to as the wrapping angle) is made larger than the angle α formed with the tangent at the end position of the magnetic tape (hereinafter referred to as the tangential angle), Furthermore, it has been proposed that the spacing distribution can be improved by configuring the winding angle to the tangent angle ratio β/α to be in the range of 1.2 to 2.5. In this case, as shown in FIG. 8, a substantially constant spacing distribution with no inclination or unevenness is obtained over almost the entire width of the sliding surface 32, and as a result1, even if there is a disturbance such as vibration, the magnetic Since the spacing on the gap 33 is maintained substantially constant, stable electromagnetic conversion characteristics can be obtained.

[Problem to be solved by the invention]

Incidentally, in recent years, this type of cassette streamer has been increasing in storage capacity and high-speed transfer. Therefore, as recording density increases, the head touch between the magnetic head and the magnetic tape becomes increasingly important, and in addition to the above-mentioned substantially constant spacing distribution without slope or unevenness, even smaller spacing is required. It looks like this.

However, the configuration of the second conventional example has a problem in that good electromagnetic conversion characteristics cannot necessarily be obtained when the magnetic tape is run at high speed as described above.

For example, FIG. 9 shows the effect on the magnetic tape when the ratio β/α between the wrapping angle and the tangent angle was set to 2.0 and a test was conducted using the configuration described in the second conventional example. This is a graph showing the relationship between the tension (hereinafter referred to as tape tension) and the head output. As shown in the figure, the head output increases as the tape tension increases, and when the tape tension reaches a certain value Ta. , thereafter, the head output decreases as the tape tension increases. In other words, the spacing changes depending on the tape tension, and therefore the head output changes depending on the tape tension as well as the above β/α.

In addition, FIG. 10 shows that the head tip radius of curvature is 2.5 mm,
β/α when testing various magnetic tape winding angles β using a magnetic head with a tangential angle α of 1.2 degrees
It is a graph showing the relationship between and output. The magnetic tape used for the measurement was a commercially available 8mm video tape.
Saturation recording was performed in advance at a recording wavelength of 1.5 μm. Further, the magnetic tape speed during reproduction was 901 PS, and the tape tension was 35 gf. In this case, the head output is maximum when β/α is in the range of 3 to 4. Also, the results of measurements of other magnetic head shapes conducted by the inventors of the present application show that the optimum values of β/α are different.

In this way, as in the second conventional example, β/α is 1.2
to 2.5 does not necessarily provide a sufficiently small spacing, and especially when the tape tension is low, considerable spacing may occur.
This results in a decrease in output, resulting in the problem that a sufficiently high recording density cannot be achieved.

(Means for Solving the Problems) Therefore, the inventors of the present application conducted various studies taking into account the arrangement relationship between the magnetic head shape and the magnetic tape, as well as the tape tension, and as a result, found that the relationship between the magnetic head and the magnetic tape was The present inventors have newly discovered a configuration that can improve electromagnetic conversion characteristics by minimizing the spacing between the two, and have now accomplished the present invention.

That is, in order to solve the above problems, the magnetic recording and reproducing apparatus of the present invention includes a magnetic head having a convex curved sliding surface on which a flexible magnetic recording medium such as a magnetic tape slides,
In a magnetic recording/reproducing device in which a magnetic gap for recording and reproducing information on the magnetic recording medium is formed approximately at the apex position of the sliding surface of the magnetic head, a tangent line at the apex position of the sliding surface and , α is the angle between the tangent at the end position of the sliding surface, and β is the angle between the direction in which the magnetic recording medium flows into the sliding surface and the tangent at the apex position of the sliding surface. , when the tension per unit width of the magnetic recording medium is T, the variation value determined by TXsin(β-α) at at least one end position of the sliding surface is from 0.12 gf/mm to 0.12 gf/mm. 3g
The present invention is characterized in that the shape of the magnetic head, the arrangement and tension of the magnetic recording medium are set so that f is in the range of 7 mm.

[For production]

As above, set the parameter value to 0.12 g f 7m
By configuring the magnetic head to fall within the range of m to 0.3 g f 7 mm, it is possible to run with the spacing between the magnetic head and the magnetic recording medium as small as possible. In this case, the above parameter value is a value that takes into account the tension T acting on the magnetic recording medium. Therefore, even when a larger tension is applied to the magnetic recording medium to run at high speed, etc. By changing the relationship between α and β to compensate for this incremental amount of tension, running with as small a spacing as possible can be maintained. As a result, it becomes possible to run the magnetic recording medium at higher speeds and maintain stable electromagnetic conversion characteristics, thereby achieving higher recording density.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

In FIG. 1, 1 is a magnetic head, 2 is a magnetic tape, and the tip end side (upper side in the figure) of the above-mentioned head 1 has a convex curved shape as a sliding surface 3 with respect to the magnetic tape 2. It is formed. Also, approximately in the center of this sliding surface 3,
A magnetic gap 4 is formed on the magnetic tape 2 for recording and reproducing. Both end sides of the sliding surface 3 are as follows:
They are formed as inclined surfaces 5, 5 which do not contact the magnetic tape 2, and are smoothly connected to both left and right ends of the sliding surface 3, respectively.

On the other hand, the magnetic tape 2 is driven at high speed by a drive mechanism (not shown) in the direction indicated by the arrow in the figure, or in the direction indicated by the arrow R when the running direction is switched, and is driven in the magnetic gap 4. Recorded and played back. Incidentally, the tape tension of the magnetic tape 2 is determined during the running of the magnetic tape 2.
It can be controlled by the drive mechanism described above. The magnetic tape 2 is guided by tape guide rollers 6 provided on both sides of the magnetic head 1 so as to wrap around the entire width of the sliding surface 3 of the magnetic head 1 in the left and right direction.

In the figure, α represents the tangent Ls at the end position of the sliding surface 3 of the magnetic head 1, the central position on the sliding surface 3,
That is, it is the angle formed with the tangent Lo at the apex position where the magnetic gap 4 is formed (hereinafter referred to as tangential angle), and β is the angle between the inflow and outflow of the magnetic tape 2 to the sliding surface 3. This is the angle between the direction and the tangent Lo at the apex position of the sliding surface 3 (hereinafter referred to as the wrap angle). Further, T indicates the tape tension per unit width of the magnetic tape 20.

In such a tape running system, the output when the tangent angle α, wrapping angle β, and tape tension T are variously changed is measured, and the parameter value P is calculated as P=T
The relationship between this parameter value P and the output when determined as Xs in (β-α) is shown in FIG. As shown in the figure, the output is maximum when the parameter value is PA, and the output decreases when the parameter value P is larger or smaller. Then, as a result of measuring the spacing in the configuration with the parameter value PA that gives the above-mentioned maximum output, the measured value is on the order of several tens of nanometers, which is approximately the same as the surface roughness of the magnetic tape 2. This could be considered the minimum realistic spacing.

Next, when driving at low speed under conditions where the above peak value can be obtained (5
Figure 3 shows the measurement results of the output during high speed running (90 IPS) and high speed running (90 IPS). The above-mentioned high-speed running test was conducted based on the deflection angle (hereinafter referred to as tilt angle) when the magnetic head 1 is swung around the center of curvature Oc of the sliding surface 3, as shown by the two-dot chain line in FIG. ) Measurements were also conducted with various changes in θ. Therefore, Fig. 3 shows the change in the output when the horizontal axis is the tilt angle θ. It is shown as

In FIG. 3, the line indicated by Wc is the output level when the tilt angle θ of the magnetic head l is set to 0 and the magnetic head l is run at low speed. In the figure, the curve indicated by WAR is the first
When the magnetic tape 2 is run at high speed on the R side in the figure, the curve indicated by WAL will be on the L side in FIG.
It shows each output when running at high speed. The magnetic head 2 used in this measurement is a magnetoresistive head (
MR head). Further, the magnetic tape 2 used is one that has been recorded in advance at a predetermined recording wavelength.

The above recording wavelength is set to a value that causes almost no core loss when the magnetic tape 2 runs at high speed, and most of the output loss during low speed and high speed running can be considered to be spacing loss. can.

As a result of the above, when the tilt angle θ is O, even when the magnetic tape speed is high, the output is only slightly lower than when the speed is low, and therefore, the distance between the magnetic head 1 and the magnetic tape 2 is The minimum spacing state is almost maintained, and even when the running direction is reversed, the same output level is maintained.

Furthermore, from FIG. 3, even if the installation causes vibration in the magnetic head 1, as long as the tilt angle is small,
Almost the same output level as above is maintained.

In this way, in the case of a configuration in which the parameter value P is an appropriate value, that is, a value close to the parameter value PA that gives the maximum output in Fig. 2, the output is almost the same even when running at high speed as when running at low speed. is obtained, and the same output level is maintained even when the direction of travel is switched.

Furthermore, even if the magnetic head 1 is slightly shaken, the above output level is maintained, and therefore there is a margin in the mounting position, so mounting the magnetic head 1 requires work and adjustment work. becomes very easy.

In Fig. 2, the parameter value at the point where the output drops below the maximum output is indicated by P, and Fig. 3 shows the output curve during high-speed running with the configuration of this parameter value P. Indicated by 'TV B R, W II L. W,
, l are the cases where the magnetic tape 2 is run at high speed on the R side in FIG. 1, and WllL is on the L side in FIG. 1, respectively. Even under these conditions, the output is almost the same as when running at low speed, and therefore the minimum spacing is obtained, but there is almost no margin for the deflection of the magnetic head 1, and therefore the position of the magnetic head 1 is Adjustment becomes difficult.

By the way, in order to find an appropriate value for the parameter value P represented by Txs in (β-α), we used a generally commercially available magnetic tape to measure magnetic heads of various shapes, winding angles of the magnetic tape, and tape. FIG. 4 shows the results of measuring the relationship between the parameter value TXsin (β-α) and the output for tension. In the figure, wh is the output upper limit line,
W! ! , indicates the lower limit line of the output. From the same figure, 0.12 to 0.3 g f 7mm sandwiching the output peak region
By setting the above parameter value P in the range of
Even at the output lower limit line W2, the output does not decrease much, so that the magnetic tape 2 can be run while the minimum spacing state is roughly maintained.

As explained above, the parameter value TXS i n(β
-α) is in the range of 0.12 to 0.3 g f 7 mm, so that the magnetic tape 2 can run at high speed while the spacing between the magnetic head l and the magnetic tape 2 is almost minimum. It is possible, and as a result,
Since spacing loss is reduced, electromagnetic conversion characteristics that enable high recording density can be obtained.

Furthermore, since magnetic tape running systems such as cassette streamers use the so-called serpet-in method, similar small spacing is required even when the magnetic tape is running in reverse. A similar minimum spacing can be obtained when the magnetic tape is running in reverse, and stable current-n conversion characteristics can be obtained.

Furthermore, since there is a margin against the deflection of the magnetic head 1, the above arrangement also has the effect that mounting and adjustment work can be easily performed.

In the above embodiment, a case was explained in which one magnetic head 1 was used. However, when a plurality of magnetic heads are used, such as a combination head, for example, the above parameters may be affected by each magnetic head. A similar effect can be obtained if all appropriate conditions are met.

〔Effect of the invention〕

As described above, the magnetic recording and reproducing apparatus of the present invention includes a magnetic head having a convex curved sliding surface on which a flexible magnetic recording medium such as a magnetic tape comes into sliding contact, and In a magnetic recording and reproducing device in which a magnetic gap for recording and reproducing information on the magnetic recording medium is formed at approximately the apex position of the surface, a tangent at the apex position of the sliding surface and an end of the sliding surface The angle formed with the tangent at the position is α
, the angle between the direction in which the magnetic recording medium flows into the sliding surface and the tangent at the apex position of the sliding surface is β,
When the tension per unit width force of the magnetic recording medium is T, at least one end position of the sliding surface is T.
If the parameter value determined by Xsin(β-α) is 0.
In this configuration, the shape of the magnetic head, the arrangement and tension of the magnetic recording medium are set so that the magnetic head is in the range of 12 gf/mm to 0°3 gf/mm.

As a result, it is possible to run with the spacing between the magnetic head and the magnetic recording medium as small as possible, and even when running at high speed by changing the tension acting on the magnetic recording medium, the above-mentioned The vehicle can be driven while maintaining the same spacing. This makes it possible to maintain good electromagnetic conversion characteristics during high-speed running, and as a result, it is possible to achieve the effect of increasing recording density.

[Brief explanation of drawings]

1 to 4 show one embodiment of the present invention. FIG. 1 is a schematic plan view of the vicinity of a magnetic head of a magnetic recording/reproducing device. FIG. 2 shows the parameter value TXsiH(β
It is a graph showing the measurement result of the output when changing ) of -. FIG. 3 is a graph showing the measurement results of the output when the deflection angle of the magnetic head is changed. FIG. 4 is a graph showing the results of measuring the relationship between the parameter value TXsin (β-α) and output using various commercially available magnetic tapes. 5 to 10 show conventional examples. FIG. 5 is a schematic plan view of the vicinity of the magnetic head of the magnetic recording/reproducing apparatus in the first conventional example. FIG. 6 is a graph showing the spacing distribution between the magnetic head and the magnetic tape in the first conventional device. FIG. 7 is a schematic plan view of the vicinity of a magnetic head of a magnetic recording/reproducing apparatus in a second conventional example. FIG. 8 is a graph showing the spacing distribution between the magnetic head and the magnetic tape in the second conventional device. FIG. 9 is a graph showing the measurement results of the output when the tape tension is changed in the configuration of the second conventional example. FIG. 1O is a graph showing the measurement results of the output when the parameter β/α is changed in the configuration of the second conventional example.

Claims (1)

[Scope of Claims] 1. A magnetic head having a convex curved sliding surface on which a flexible magnetic recording medium such as a magnetic tape comes into sliding contact; , in a magnetic recording and reproducing device in which a magnetic gap for recording and reproducing is formed in the magnetic recording medium, a tangent at the vertex position of the sliding surface and a tangent at the end position of the sliding surface; α is the angle formed between the direction in which the magnetic recording medium flows into the sliding surface and the tangent at the apex position of the sliding surface is β, and T is the tension per unit width of the magnetic recording medium. When, at least one end position on the sliding surface, T×sin(β−α)
The magnetic head shape and the arrangement and tension of the magnetic recording medium are set so that the parameter value determined by is in the range of 0.12 gf/mm to 0.3 gf/mm. Recording and playback device.