JPH06267043A - Magnetic head support mechanism - Google Patents

Abstract

PURPOSE:To obtain a magnetic head support mechanism which make possible the adjusting of the height of a magnetic head without removing a motor from an upper rotary drum by reducing the twisting of a head base of a magnetic head mounting section as causing errors in the azimuth angle of a magnetic head in the adjustment of the height of the magnetic head to prevent the lowering of a signal output in an interchangeable reproduction. CONSTITUTION:A slit 11 is formed in the direction of the center of the rotation of a rotary drum on a head base at an intermediate part between two magnetic heads 8a and 8b while extending parts 6c and 6d are provided with a shape of sticking out on both side parts of positions of mounting the two magnetic heads. Screw holes 13a and 13b are formed at the extending parts 6c and 6d respectively and height adjusting screws 12a and 12b are arranged in the screw holes 13a and 13b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head device such as a video tape recorder and a digital audio tape recorder.

[0002]

2. Description of the Related Art FIG. 16 shows, for example, Japanese Patent Laid-Open No. 63-19331.
FIG. 17 is a plan view showing a conventional magnetic head supporting mechanism shown in Japanese Patent Laid-Open No. 6-67, FIG. 17 is a front view thereof, and FIG. 18 is a sectional view of a rotary drum device to which the magnetic head supporting mechanism is attached. In FIG. 18, 1 is a lower fixed drum having a lead for holding the magnetic tape 2 at an appropriate position at a predetermined angle, 3 is a wedge-shaped groove 4, and the lower fixed drum 1 is located at the center of the lower fixed drum 1. Axis 5 mounted coaxially with respect to is an upper rotating drum having a sleeve in the center,
A lubricant is injected between the sleeve and the shaft 3. 6 is a head base fixed to the upper rotary drum 5 by a fixing screw 7, 8 is a magnetic head fixed to a predetermined position of the head base 6, 9 is a motor mounted coaxially on the upper rotary drum 5, and 10 is It is a rotary transformer that transmits signals in a non-contact manner.

In FIG. 16, reference numerals 8a and 8b denote magnetic heads fixed to the head base 6 at predetermined positions.
Reference numeral 11 is a slit formed in the head base 6 so as to divide the magnetic head mounting portion of the head base 6 into two parts, and 6e and 6f are divided into two parts by the slit 11 to prevent deformation when the height of the magnetic head 8a or 8b is adjusted. It is a plate portion of the head base 6 to be generated. In addition, in FIG.
Reference numerals a and 12b are height adjusting screws for changing the height of the magnetic head.

Regarding the conventional magnetic head supporting mechanism as described above, first, a rotary head drum device to which the magnetic head supporting mechanism is attached will be described. When the upper rotary drum 5 to which the motor 9 is fixed is rotated by driving the motor 9, the lubricant is provided by the pumping action of the sleeve formed on the upper rotary drum 5 and the wedge-shaped groove 4 formed on the shaft 3. Pressure is generated on the upper rotating drum 5
Makes stable rotation without contact with the shaft 3. As a result, the magnetic head 8 fixed to the head base 6 attached to the upper rotary drum 5 passes through the magnetic tape 2 at a predetermined angle, and at this time, the signal transmitted to the magnetic head 8 by the rotary transformer is magnetic. It is recorded or reproduced on the tape 2.

Next, the operation of the conventional magnetic head support mechanism will be described. As shown in FIG. 19, for example, the height of the other magnetic head 8b deviates from the predetermined position with respect to the height of the magnetic head 8a, and there is an overlapping portion h as shown by the shaded portion. If the magnetic tape 2
The signals written in the above are overwritten and become as shown in FIG. 20, resulting in a difference in track width. When the magnetic tape 2 is reproduced by another rotating drum device, the magnetic head 8 cannot accurately trace the recording track, and the output is reduced. In this case, as shown in FIG. 27, the upper rotary drum 5 to the motor 9
21 is removed, the magnetic head 8 is moved by the height adjusting screw 12b attached to the upper rotary drum 5 as shown in FIG.
By adjusting the height of b to a predetermined height, it is necessary to equalize the track widths of the signals recorded on the magnetic tape 2 as shown in FIG.

Here, by providing a screw hole for attaching the head base 6 to the upper rotary drum 5 to the side of the slit 11 so that the head base 6 can be mounted on a small rotary drum device, the length of the head base 6 in the radial direction is increased. Is shortened.

In the conventional magnetic head support mechanism, the slit 11 has a substantially L shape as shown in FIG. 16, and the rigidity of the plate portions 6e and 6f having the magnetic head 8a or 8b attached to the fixing screw 7 is changed. ing. This allows
For example, when the height of the magnetic head 8b is adjusted, the height change of the magnetic head 8a can be minimized by reducing the influence on the height of the magnetic head 8a attached adjacently. It is described that the height of the head 8 can be easily adjusted.

[0008]

However, in the conventional magnetic head supporting mechanism constructed as described above, the height adjustment screw 12a or 12b and the fixing screw 7 are not properly positioned, so that the height adjustment screw is adjusted. When the height of the magnetic head 8 is adjusted by the screws 12a or 12b, a moment that causes a twist is applied to the plate portion 6e or 6f of the head base 6 to which the magnetic head 8 is attached.
Alternatively, the 6f will be twisted. 23 and 24 are the analysis results of the perspective view and the contour diagram of the deformation by the structural analysis program. 23 shows the case where the height of the magnetic head 8b is adjusted, and FIG. 24 shows the case where the magnetic head 8a is adjusted.
This is the case when the height of is adjusted. From these results,
It can be seen that the contour line has an angle with respect to the direction connecting the two fixing screws, and the plate portion 6e or 6f is twisted and deformed with respect to the mounting surface of the head base 6 of the upper rotary drum 5.

Therefore, for example, when the height of the magnetic head 8b is adjusted by the height adjusting screw 12b installed near the magnetic head 8b, the influence on the height of the adjacent magnetic head 8a can be prevented. As shown in FIG. 2, the plate portion 6f to which the magnetic head 8b is attached is twisted with respect to the attachment surface of the head base 6 of the upper rotary drum 5,
As shown in 6, the azimuth angle that was θ0 becomes θ1 and an error Δθ (= θ1−θ0) occurs. Then, when the magnetic tape 2 recorded by this rotary drum device is reproduced by another rotary drum head device, there is a problem that the signal output is lowered due to the error of Δθ in the azimuth angle. .

Further, when the height of the magnetic head 8 is adjusted by the height adjusting screw 12, it is necessary to remove the motor 9 from the upper rotary drum 5 as shown in FIG. The motor 9 is composed of a yoke composed of a magnet and a magnetic body, and is a heavy component among the components constituting the drum. For this reason, there is a problem in that the balance of the drum rotating portion is lost due to the mounting error caused by the mounting and dismounting of the motor to cause whirling, so that the balance has to be readjusted and the number of steps for adjustment increases.

The present invention has been made in order to solve the above-mentioned problems, and a head base having a magnetic head attached to a head base mounting surface of an upper rotating drum, which causes an error in an azimuth angle of the magnetic head, is provided. By reducing the twist of the plate part, the purpose is to obtain a magnetic head support mechanism that can prevent a decrease in signal output during compatible reproduction, and by arranging the height adjustment screw on the head base, An object of the present invention is to obtain a magnetic head support mechanism capable of reducing the number of steps at the time of adjustment by preventing the imbalance, by performing the adjustment without removing the motor when adjusting the height of the magnetic head.

[0012]

In the magnetic head support mechanism according to the present invention, a slit is formed in the center of the head of the two magnetic heads in the direction of the center of rotation of the rotary drum, and the two magnetic heads are mounted. Protruding extending portions are provided on both sides of the position, screw holes are formed in the extending portions, and height adjusting screws are arranged in the screw holes.

Further, the head base has a shape including a gap portion near the mounting positions of the two magnetic heads and a wide portion formed to have a wider width than this, and extends to both sides of the magnetic head mounting position. An existing portion is provided, a screw hole is formed in each of the extended portions, and a height adjusting screw is arranged in the screw hole.

[0014]

According to the present invention, a slit is formed in the head base in the middle of the two magnetic heads in the direction of the center of rotation of the rotary drum, and screw holes are formed on both sides of the two magnetic head mounting positions. The height of the magnetic head is adjusted by the height adjustment screw placed in this screw hole to reduce the error in the azimuth angle that occurs during height adjustment. work.

When adjusting the height of the magnetic head,
Since it is not necessary to remove the motor from the upper rotary drum, it works so as not to cause imbalance in the rotating part.

[0016]

【Example】

Example 1. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is a front view thereof, and a sectional view of a rotary drum device to which a magnetic head supporting mechanism of this embodiment is attached is the same as FIG. Omit it. In FIG. 1, 6 is a head base in which a substantially L-shaped slit 11 is formed, 8a, 8
Reference numeral b denotes a magnetic head fixed in parallel with the head base 6, and the slit 11 has a gap 11a formed between the magnetic heads 8a and 8b and has a wide dimension w in the downward direction in the drawing. It has a shape composed of the formed wide portion 11b. Reference numeral 7 is a fixing screw for attaching the head base 6 to a rotating drum (not shown). The width of the head base 6 becomes narrow between the attaching positions of the magnetic heads 8a and 8b and the attaching position of the fixing screw 7. Narrow part 6
a and 6b are formed and the magnetic heads 8a and 8b are formed.
The protruding portions 6c and 6d are formed on both sides of the mounting portion b, and the screw holes 1 are formed in the extending portions 6c and 6d, respectively.
3a and 13b are provided. Also, 12a, 12b
Is a height adjusting screw arranged in the screw holes 13a and 13b of the extending portions 6c and 6d.

Next, the operation will be described. The drum assembly assembled with a predetermined accuracy is the upper rotary drum 5
The balance is adjusted in the rotating part, mainly, and then the relative height (step) of each magnetic head is measured and adjusted. At this time, if the step is not of a predetermined accuracy, the upper rotary drum 5 is first removed from the lower fixed drum 1 as shown in FIG. The height adjusting screws 12a and 12b arranged in the screw holes 13a and 13b formed in the extending portions 6c and 6d are opposite to the portion where the motor 9 of the upper rotary drum 5 is attached, that is, clockwise from the lower side in the drawing. Alternatively, by rotating it counterclockwise, the height adjusting screw 1
The amount of protrusion of 2a or 12b can be adjusted in the vertical direction. Since the end portion of the height adjusting screw 12a or 12b is in contact with the upper rotary drum 5, the reaction force causes the portion of the head base 6 to which the magnetic head 8 is attached to be displaced to adjust the height of the magnetic head 8. Is done. That is,
Since the step can be adjusted without removing the motor 9, the balance of the rotating portion is not deteriorated. The deformation of the head base 6 when the height of the magnetic head 8a or 8b is adjusted will be described in detail because the structural analysis was performed.

4A to 4E show positions where the position of the height adjusting screw 12 is sequentially moved. FIG. 5 shows the relationship between the position of the height adjusting screw 12b and the torsion angle of the magnetic head mounting portion at that time, using the results of structural analysis by the structural analysis program at the positions shown in FIG. is there. As shown in this figure, when the magnetic head 8b is arranged at points A, B, and C, the magnetic head 8b is tilted clockwise in FIG. 2, and when it is arranged at point E, it is tilted counterclockwise. Becomes It can be seen that when the magnetic head mounting portion is arranged at the point D, the torsion of the magnetic head mounting portion becomes zero. That is, the azimuth angle error can be minimized by forming the screw hole 13b near the position D and disposing the height adjusting screw 12b in this screw hole.

Further, in FIG. 6, a screw hole 13b is formed at a position D, and a height adjusting screw 12b is arranged in the screw hole. The analysis result of the perspective view and the contour diagram of the deformation of the head base 6 by the analysis program is shown. 7 is an analysis result when the height of the magnetic head 8a is adjusted by the height adjusting screw 12a. From these results, it is understood that the contour line near the magnetic head 8a or 8b of the head base 6 is substantially parallel to the straight line connecting the fixing screws 7, and the error of the azimuth angle is small.

Next, the calculation results when numerical values are concretely entered will be shown. A magnetic head when the height of the magnetic head 8b is adjusted by changing the width w by setting the depth d of the substantially L-shaped slit 11 to 3 mm and changing the width w in the magnetic head supporting mechanism having the dimensions as shown in FIG. 8a shows the influence of 8a on the height direction.
It was shown to. The circles are the analysis results, and the solid lines are the approximate curves by the least squares method. As shown in this figure, when the height of the magnetic head 8a or 8b is adjusted when the slit width w is small, the influence on the adjacent magnetic head 8b or 8a is large and the adjustment becomes difficult. It can be seen that the slit width w is required.

In the actual height adjustment of the magnetic head, the adjustment amount is about 5 to 10 (μm) due to the selective use of the magnetic head 8. Therefore, if the head height adjustment accuracy is set to about ± 1 (μm), the degree of influence of the adjacent heads is about 10%, which allows easy adjustment. FIG. 9 shows the relationship between the slit depth d and the slit width w obtained when the influence of the magnetic head 8 on the adjacent heads is about 10% or less by a structural analysis program. Is an approximate curve by the method of least squares. Adjacent heads during height adjustment by setting the slit depth d and slit width w in the region above this approximate curve, that is, the region represented by w ≧ -0.354d ² +0.635 d + 3.134 (unit mm) The impact on the magnetic head 8a or 8b is about 10% or less.
The height can be easily adjusted. Further, in FIG. 10, the head base 6 having the slit depth d and the slit width w satisfying this relationship is analyzed by the structural analysis program, and the height adjustment amount and the adjustment-side magnetic head 8b (.largecircle.
The magnetic head 8a adjacent to the displacement amount when the
The amount of displacement of (□) is obtained, and both the magnetic head 8a whose height is adjusted and the adjacent magnetic head 8b are displaced in proportion to the amount of height adjustment, and the influence on the adjacent head is also 1 It will be about 50%.

Example 2. In the first embodiment, the slit 11
Is approximately L-shaped, but as shown in FIG.
If 1 is substantially T-shaped, the same operation as in the embodiment can be obtained. In FIG. 11, 6 is a head base, 8a and 8b are magnetic heads fixed to the head base 6, 7 is a fixing screw of the head base 6, 6a and 6b are narrow portions of the head base, and 6c and 6d are magnetic heads. The extending portions 13a and 13b projecting from both sides of 8a and 8b are extended portions 6c and 6b.
screw holes formed in d. Reference numeral 11 is a slit formed in the head base 6 and has a gap 1 with a depth d.
1a and a wide portion 11b having a width w are formed into a substantially T shape. Further, 12a and 12b are height adjusting screws arranged in screw holes 13a and 13b formed in the extending portions 6c and 6d.

Next, the operation of the magnetic head supporting mechanism shown in FIG. 11 will be described. FIG. 12 is a perspective view and a contour diagram analysis result of deformation by the structural analysis program when the height of the magnetic head 8b is adjusted by the height adjusting screw 12b. From this figure, in the portion of the head base 6 where the magnetic head 8b is attached, the contour lines are substantially parallel to the direction of the straight line connecting the two fixing screws 7, and the twist in this portion is small. Therefore, the magnetic head 8
The azimuth error of a or 8b becomes small, and an appropriate signal output can be obtained even when the magnetic tape 2 recorded by the rotary drum device equipped with this magnetic head support mechanism is reproduced by another rotary drum device.

When the height of the magnetic head 8 is adjusted, the upper rotary drum 5 is removed from the lower fixed drum 1 and the magnetic head 8 is adjusted by a height adjusting screw 12 from the side opposite to the motor 9 of the upper rotary drum 5. Since the height can be adjusted without removing the motor 9, the balance of the rotating portion is not deteriorated.

Further, by making the shape of the slit 11 substantially T-shaped as shown in FIG. 11, the following effects can be obtained in addition to the above-mentioned action of reducing the error of the azimuth angle. That is, since the head base generally requires flatness of several μm, it is subjected to flattening.
At this time, if the rigidity of the deformed portions 6a and 6b is low, there is a possibility that breakage may occur in this portion. In such a case, the rigidity can be increased by increasing the widths of the narrow portions 6a and 6b, and such a failure of destruction can be reduced.

Example 3. In this embodiment shown in FIG. 13, the slit 11 has a substantially triangular shape, and FIG. 14 is a plan view when the head base 6 is attached to the upper rotary drum 5. Further, FIG. 15 is a perspective view and a contour diagram analysis result of deformation by the structural analysis program when the height of the magnetic head 8b is adjusted by the height adjusting screw 12b. As shown in this figure, even if the slit 11 is formed in a substantially triangular shape, the twist angle of the magnetic head mounting portion is small, the error of the azimuth angle is small, and a proper signal output is obtained even during compatible reproduction. Can be obtained.

When adjusting the height of the magnetic head 8, the upper rotary drum 5 is removed from the lower fixed drum 1, and the magnetic head 8 is adjusted by the height adjusting screw 12 from the side opposite to the motor 9 of the upper rotary drum 5. Since the height can be adjusted without removing the motor 9, the balance of the rotating portion is not deteriorated.

[0028]

Since the present invention is configured as described above, the height adjusting screw is arranged in the screw hole formed in the extending portion of the head base, and the height adjusting screw is used to move the magnetic head. By adjusting the height, the error of the azimuth angle can be reduced by reducing the twist of the plate part that is divided by the slit of the head base and fixed to the magnetic head.
An appropriate signal output can be obtained even during compatible reproduction. Also, since the height can be adjusted without removing the motor when adjusting the height of the magnetic head,
It is possible to reduce the number of adjustment steps without disturbing the balance of the rotating portion of the drum.

[Brief description of drawings]

FIG. 1 is a plan view showing a magnetic head support mechanism according to a first embodiment of the present invention.

FIG. 2 is a front view of FIG.

FIG. 3 is a partial cross-sectional side view of the rotary head drum device of the first embodiment.

FIG. 4 is a plan view showing an arrangement position of height adjusting screws according to the first embodiment.

FIG. 5 is a diagram showing the relationship between the position of the adjusting screw and the helix angle of the first embodiment.

FIG. 6 is a diagram showing an analysis result of the magnetic head support mechanism of the first embodiment.

FIG. 7 is a diagram showing an analysis result of the magnetic head support mechanism of the first embodiment.

FIG. 8 is a diagram showing the slit width of the head base and the degree of influence on an adjacent magnetic head in Example 1.

FIG. 9 is a diagram showing the influence of the slit depth and width of the head base on the adjacent magnetic head in Example 1.

FIG. 10 is a diagram showing the adjustment amount of the height adjustment screw and the displacement amount of the magnetic head in the height direction according to the first embodiment.

FIG. 11 is a plan view showing a magnetic head support mechanism according to the second embodiment of the present invention.

FIG. 12 is a diagram showing an analysis result of a magnetic head support mechanism of Example 2.

FIG. 13 is a plan view showing a magnetic head support mechanism in Embodiment 3 of the present invention.

FIG. 14 is a plan view of an upper rotating drum according to a third embodiment.

FIG. 15 is a diagram showing an analysis result of a magnetic head support mechanism of Example 3;

FIG. 16 is a plan view showing a conventional magnetic head support mechanism.

FIG. 17 is a front view showing a conventional magnetic head support mechanism.

FIG. 18 is a sectional side view of a rotary drum device equipped with a conventional magnetic head support mechanism.

FIG. 19 is a front view showing a case where there is a magnetic head height deviation of a conventional magnetic head support mechanism.

FIG. 20 is a pattern diagram of a recording track when there is a magnetic head height deviation of a conventional magnetic head support mechanism.

FIG. 21 is a front view showing a conventional magnetic head support mechanism after adjustment of magnetic head height deviation.

FIG. 22 is a pattern diagram of a recording track after a magnetic head height deviation adjustment of a conventional magnetic head support mechanism.

FIG. 23 is a diagram showing an analysis result of a conventional magnetic head support mechanism.

FIG. 24 is a diagram showing an analysis result of a conventional magnetic head support mechanism.

FIG. 25 is a front view showing a state in which a conventional magnetic head support mechanism is twisted due to a magnetic head height adjustment.

FIG. 26 is a partially enlarged view of the conventional magnetic head support mechanism during magnetic head height adjustment.

FIG. 27 is a partial cross-sectional view of the conventional magnetic head support mechanism with the motor removed.

[Explanation of symbols]

 1 Lower fixed drum 2 Magnetic tape 3 Shaft 5 Upper fixed drum 6 Head base 8 Magnetic head 9 Motor 11 Slit 12 Height adjusting screw 13 Screw hole

Claims (2)

[Claims] 1. A head base mounted on an upper rotary drum which is wound with a magnetic tape and rotated at a predetermined rotation, two magnetic heads arranged in parallel in the rotation direction and fixed to the head base, and the magnetic heads. In a magnetic head support mechanism consisting of a height adjustment screw for adjusting the height of the head,
A slit is formed in the head base in the middle of the two magnetic heads in the direction of the center of rotation of the rotary drum, and extended portions having a shape projecting on both sides of the two magnetic head mounting positions are provided. A magnetic head supporting mechanism is characterized in that a threaded hole is formed in this extending portion, and the height of the magnetic head is adjusted by the height adjusting screw arranged in the threaded hole. 2. The slit formed in the head base has a shape including a gap portion near the mounting positions of the two magnetic heads and a wide portion formed in a wide dimension by the gap portion. 2. The magnetic head support according to claim 1, wherein the height of the magnetic head is adjusted by the height adjusting screw arranged in a screw hole formed in an extending portion protruding on both sides of the mounting position. mechanism.