JPH0375933B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a head adjustment mechanism, and in particular, to a cassette tape recorder having an auto-reverse function, which adjusts the azimuth angle of a magnetic head according to the running direction of a magnetic tape. This invention relates to a head adjustment mechanism such as a head adjustment mechanism.

[Conventional technology]

In general, when playing back a magnetic tape in a cassette tape recorder, the most faithful playback condition is achieved when the playing core gap of the magnetic head and the running direction of the magnetic tape, that is, the magnetic recording surface, are directly opposite to each other. However, due to the inclination of the head surface or the inclination of the capstan, the magnetic tape usually runs in an angular direction slightly deviating from a predetermined position.
For this reason, in the past, one end of the base plate to which the magnetic head was attached was fixed, the other end was slightly bent using the biasing force or elastic force of a spring, and an adjustment screw was used to adjust the distance between the recording surface and the core gap. He was making adjustments to face him directly.

However, the inclinations of the magnetic heads and capstans differ for each device, and must be adjusted for each device. However, in cassette tape recorders that are commonly used these days and have an auto-reverse mechanism that allows playback of magnetic tape in both directions, if the recording surface and core gap are adjusted to face each other in the forward direction of the magnetic tape, there will be a slight misalignment when the magnetic tape is running in the reverse direction. There were cases where this occurred. In such a case, the best point when traveling in the forward direction is slightly shifted, and an adjustment is made by finding a compromise with the best point when playing in the reverse direction. However, such an adjustment method not only requires complicated work but also results in poor uniformity in performance. In order to solve this problem, a magnetic head azimuth adjustment device was developed in 17624 (1983) that adjusted the angle of the head separately for each run of the magnetic tape and found the best point.
It is known in the publication no.

9 and 10 are diagrams showing the above-mentioned azimuth adjustment device for a magnetic head, in particular, FIG. 9 shows an external perspective view of the main part, and FIG. 10 shows a sectional view of the main part.

First, a conventional azimuth adjustment device will be described with reference to FIGS. 9 and 10. The magnetic head 1 has a head mounting plate 2 made up of a leaf spring.
One end 2a of the head mounting plate 2 is mounted by mounting screws 5 on a mounting base 4 fixed on a reciprocating head base plate 3. A groove 6 is formed on the other end 2b side of the head mounting plate 2. Other end 2b of head mounting plate 2
A fulcrum shaft 7 is vertically fixed on the side and on the head substrate 3. A rotary lever 8 having a substantially U-shaped cross section is fitted into the fulcrum shaft 7 through a pair of upper and lower through holes 9a and 9b, and the rotary lever 8 rotates around the axis of the fulcrum shaft 7. It is configured to be freely rotatable in the horizontal direction and slidable up and down in the axial direction.

On the same circumference of the top plate 8a of the rotary lever 8,
A pair of adjustment screws 11 and 12 for adjusting azimuth are both mounted downward. Both of these adjustment screws 11 and 12 are screwed into a pair of screw holes 13 and 14 provided in the upper surface plate 8a and penetrate downward.
Compression springs 15 and 16 for preventing loosening are inserted between the heads of the adjustment screws 11 and 12 and the top plate 8a in a pre-compressed state, respectively.

The other end 2b of the head mounting plate 2 is in contact with the tip of the lower plate 8b of the rotary lever 8. A height reference shaft 18 inserted into the groove 6 of the head mounting plate 2 is vertically fixed on the head board 3, and its upper end surface is configured as a height reference surface. A washer 20 is fitted to the upper end of this height reference shaft 18, and the washer 20 and the other end 2 of the head mounting plate 2
A compression spring 21 for pressing the head mounting plate is inserted in a pre-compressed state between the height reference shaft 18 and the height reference shaft 18.

A thin leaf spring 22 is inserted between the tips (lower ends) of both adjusting screws 11 and 12 and the height reference surface 19 at the upper end of the height reference shaft 18. This leaf spring 22 has a substantially L-shape, and one end thereof is inserted into the fulcrum shaft 7 through a through hole (not shown), and a protrusion 24 integrally provided on the other end is connected to the rotation lever 8.
It is configured to be engaged with an engagement hole 25 provided at the tip of the top plate 8a and rotated together with the rotary lever 8. In addition, the interlocking lever 26 described later
The tip of the rotary lever 8 is connected to a part of the lower plate 8b of the rotary lever 8 via a pin 27.

Next, a method for adjusting the azimuth angle in the conventional azimuth adjustment device described above will be explained. When the magnetic tape 29 is running in the forward direction, the interlocking lever 26
is moved in the direction of arrow c in FIG.
is rotated in the direction of arrow d. As a result, the tip (lower end) of one adjustment screw 11 is aligned with the height reference axis 18.
The rotary lever 8 is brought into contact with the height reference surface 19 at the upper end via the leaf spring 22, and the rotary lever 8 is moved along the fulcrum shaft 7 in the direction of the arrow e.
direction by the compression spring 21. At the tip of the lower plate 8b of the rotary lever 8, the head mounting plate 2 has its own elasticity and compression spring 21.
The head mounting plate 2 is bent by a predetermined angle in the direction of arrow f, and the magnetic head 1 is tilted by a predetermined angle. In this forward running state, by adjusting the adjustment screw 11, the compression spring 21
The rotary lever 8 is moved up and down along the fulcrum shaft 7 to adjust the azimuth adjustment (gap verticality adjustment) of the magnetic head 1 by adjusting the deflection angle of the head mounting plate 2. can be done.

On the other hand, when the magnetic tape 29 runs in the reverse direction, the interlocking lever 26 moves in the direction of arrow i, and the rotary lever 8 is rotated in the direction of arrow j. As a result, the tip (lower end) of the other adjusting screw 12 is aligned with the height reference axis 1.
The rotary lever 8 is brought into contact with the height reference surface 19 at the upper end of the lever 8 via the leaf spring 22, and the rotary lever 8 is slid along the fulcrum shaft 7 in the direction of the arrow e against the compression spring 21. Note that the spring 22 is bent at this time. As the lower plate 8b of the rotary lever 8 moves, the other end 2b of the head mounting plate 2 is pushed up against its own elasticity and compression spring 21, and the head mounting plate 2 is moved in the direction of arrow l. It bends at a predetermined angle. As a result, the magnetic head 1 is tilted at a predetermined angle. By adjusting the adjusting screw 12 while the head is running in the opposite direction, the rotary lever 8 can be adjusted to move up and down along the fulcrum shaft 7 in cooperation with the compression spring 21, and the bending angle of the head mounting plate 2 can be adjusted. The azimuth of the magnetic head 1 can be adjusted by adjusting the verticality of the gap.

[Problem that the invention seeks to solve]

In the above-mentioned azimuth adjustment device, it is necessary to adjust the azimuth angle using the adjusting screw 11 when the vehicle is traveling in the forward direction, and it is necessary to adjust the azimuth angle using the adjusting screw 12 when traveling in the reverse direction. However, the adjusting screw 11 corresponds to when traveling in the forward direction, and the adjusting screw 12
If you don't remember that this corresponds to when traveling in the opposite direction, you will not know which adjustment screw to turn to adjust the azimuth angle in which direction.

In addition, since the lower ends of both adjustment screws 11 and 12 are in contact with the tip of the reference shaft 18 via the thin leaf spring 22, the tip of the reference shaft 18 may wear out over many years of use, causing the rotation of the rotary lever 8. There is a risk that the surface will not be smooth. Moreover, if the tip of the reference shaft 18 wears out, both adjusting screws 11 and 12
This will cause the azimuth angle adjusted by .

Furthermore, in the above-mentioned azimuth adjustment device,
The rotating lever 8 rotates depending on the running direction of the magnetic tape 29.
Since the rotating lever 8 rotates, vibrations are transmitted to the adjusting screws 11, 12 via the compression springs 15, 16, and the vibrations cause the screws 11, 12 to move in either direction. There is a risk of rotation in the direction. For this reason, there have been various drawbacks in that the azimuth adjusted by the adjusting screws 11 and 12 is distorted.

Therefore, the main object of the present invention is to provide a head adjustment mechanism which can solve the various problems mentioned above and which can easily adjust the azimuth according to the running direction of the magnetic tape.

[Means for solving problems]

In this invention, one end of a support to which a magnetic head is attached is fixed, the other end is pushed down by elastic force, and the adjustment is guided by a guide member so that it comes into contact with the lower surface of the other end of the support. A member is provided, a pair of adjusting screws are provided on the adjusting member, and a sliding body provided so as to be slidable is slid in a horizontal direction to come into contact with the lower part of one of the pair of adjusting screws, and the sliding body is moved upwardly. The azimuth angle of the magnetic head is adjusted by pushing up the other end of the support through an adjustment member.

[Effect]

In the head adjustment mechanism of the present invention, the sliding body is slid according to the running direction of the magnetic tape and brought into contact with the lower end of one of the pair of adjustment screws, and the adjustment screw is pushed upward. The other end of the support is then pushed up via the adjustment member to adjust the azimuth angle of the magnetic head. Therefore, since the mechanism only moves by sliding or moving up and down,
No rotational force is applied to the adjustment screw, and the azimuth angle of the magnetic head can be adjusted simply by adjusting the adjustment screw on the side facing the running direction of the magnetic tape.

〔Example〕

FIG. 1 is a diagram showing the overall configuration of a car stereo to which an embodiment of the present invention is applied. First, the configuration of the main parts of a car stereo will be explained with reference to FIG. The main base 31 is mainly provided with a motor 32, flywheels 33 and 34, and reel rests 35 and 36. Rotational force is transmitted to the flywheels 33 and 34 from the motor 32 via a belt 37. A capstan 38 is provided on the flywheel 33, and the capstan 38, together with a pinch roller 39, causes the magnetic tape 42 to run in the forward direction (F). On the other hand, a capstan 40 is attached to the flywheel 34, and the capstan 40, together with a pinch roller 41, causes the magnetic tape 42 to run in the opposite direction (R). Further, the main base 31 is provided with a base head 60 provided with an azimuth adjustment mechanism, which is a feature of the present invention. A cam plate head 50 is provided on the back side of the main base 31 of the base head 60.

FIG. 2 is an exploded perspective view of an embodiment of the present invention, FIG. 3 is an external view of the sliding plate 70 included in FIG. 2, and FIG. 4 is a vertical cross-section of an embodiment of the invention. It is a diagram.

Next, the structure of the head adjustment mechanism will be explained with reference to FIGS. 2 to 4. The head adjustment mechanism is mainly composed of a cam plate head 50, a base head 60, a sliding plate 70, and a head support 80. Guide grooves 54 and 55 are formed in the cam plate head 50, into which pins (not shown) are inserted. The cam plate head 50 moves in the direction of arrow F when the magnetic tape 42 is running in the forward direction, and moves in the direction of arrow R when moving in the reverse direction. Further, cams 52 and 53 are formed at both ends of the cam plate head 50. and,
When the cam plate head 50 moves in the direction of arrow F, the pin of the pinch roller 39 shown in FIG. Let it run. Further, when the cam plate head 50 moves in the direction of arrow R, the pin of the pinch roller 41 engages with the cam 53, brings the pinch roller 41 into close contact with the capstan 40, and causes the magnetic tape 42 to run in the opposite direction. Furthermore, a cam hole 51 is formed in the cam plate head 50. The cam hole 51 is into which a sliding pin 71 formed on the sliding plate 70 is inserted, and has portions 511 and 512 with which the sliding pin 71 comes into contact. The base head 60 is mainly used to attach the magnetic head 43 and the head support 80. A sliding plate 70 is attached to the base head 60.
An oval escape hole 61 into which a sliding pin 71 is inserted is formed, and a head fixing pin 62 for fixing the magnetic head 43 is attached near the escape hole 61. The base head 60 also has two pins 65 and 6.
6 is provided. These pins 65 and 66 restrict the sliding movement of the sliding plate 70. A half-opened base 67 is formed between the pins 65 and 66. Two rollers 68 and 69 are provided to roll on the base 67. The base 67 is
When the magnetic tape 42 runs in the direction of arrow F, as shown in FIG. The roller 69 is placed on top and serves as an adjustment base for an adjustment screw 86, which will be described later. In this way, the two rollers 68, 69
The reason why the rollers 68 and 69 are provided is to smooth the sliding operation by rotating the rollers 68 and 69, thereby reducing wear on the sliding parts. Furthermore, the base head 6
0 is provided with a fixed guide pin 63 and a guide pin 64. The fixed guide pin 63 serves as a sliding reference for the adjustment table 83 to be described later to slide in the vertical direction, and the guide pin 64 serves as a guide when the adjustment table 83 slides in the vertical direction. .

The sliding plate 70 slides on the base head 60 in the direction of arrow F or the direction of arrow R. A sliding pin 7 protrudes downward from one end of the sliding plate 70.
1 is formed, and a long groove 72 is formed at the other end.
Further, an oblong hole 7 is provided on the sliding pin 71 side of the sliding plate 70.
3 is formed. The long groove 72 has a base head 60.
A pin 65 is inserted into the oblong hole 73, and a pin 66 is similarly inserted into the oblong hole 73. Furthermore, roller insertion holes 74 and 75 are formed between the long groove 72 and the oblong hole 73 to insert the rollers 68 and 69, respectively.

Therefore, when the sliding pin 71 is inserted into the cam hole 51 of the cam plate head 50 through the escape hole 61 of the base head 60 and the cam plate head 50 moves in the direction of arrow F, The sliding pin 71 comes into contact with the end 512 of the hole 51 and causes the sliding plate 70 to slide in the direction of arrow F. Furthermore, when the cam plate head 50 slides in the direction of arrow R,
The sliding pin 71 is pushed by the end 511 of the cam hole 51, and the sliding plate 70 slides in the direction of arrow R.

The head support 80 supports the magnetic head 43. That is, the magnetic head 43 is attached to the base plate 8.
Fixed to 1. A through hole is formed at one end of the base plate 81 for screwing the head fixing pin 62 of the base head 60 with a set screw 87, and a groove for inserting the fixed guide pin 63 is formed at the other end. Furthermore, a head pressing spring 82 having a force for pressing the base plate 81 clockwise around the head fixing pin 62 is provided. A set screw 87 is attached to one end of this head pressing spring 82 along with a base plate 81.
A through hole for screwing the head fixing pin 62 is formed therein, and a long groove for inserting the fixing guide pin 62 is formed at the other end. One end of each of the base plate 81 and the head pressing spring 82 is screwed to the head fixing pin 62 by a set screw 87, and the other end of each is screwed to the fixed guide pin 62.
3 is inserted. Therefore, the base plate 81 has one end as a fulcrum and the other end as the fixed guide pin 63.
However, the adjustment table 83 moves up and down along the fixed guide pins 63 and 64.

The adjustment table 83 is configured to slide in the vertical direction along the fixed guide pin 63 and the guide pin 64. For this purpose, an adjustment screw 8 is provided on the adjustment table 83.
5 and 86 are screwed into the magnetic tape 4.
2 along the running direction. Adjustment screw 85
is used to adjust the azimuth angle of the magnetic head 43 when the magnetic tape 42 runs in the direction of arrow F, and the adjustment screw 86 adjusts the azimuth angle of the magnetic head 43 when the magnetic tape 42 runs in the direction of arrow R. It is something to do. Therefore,
The adjusting screw 85 corresponds to the direction when the magnetic tape 42 runs in the forward direction, and the adjusting screw 86 corresponds to the direction when the magnetic tape 42 runs in the reverse direction. Therefore, when adjusting the azimuth angle of the magnetic head 43, by turning the adjusting screw on the side facing the running direction of the magnetic tape 42, the azimuth angle can be adjusted in accordance with that direction.

FIG. 5 is a plan view of the head adjustment mechanism when the magnetic tape is running in the forward direction, and FIG. 6 is a front view of the same. FIG. 7 is a plan view of the head adjustment mechanism when the magnetic tape is running in the reverse direction, and FIG. 8 is a front view of the same.

Next, the azimuth adjustment of the magnetic head 43 when the magnetic tape runs in the forward direction will be explained with reference to FIGS. 5 and 6. When adjusting the azimuth of the magnetic head 43 during forward running, the adjusting screw 85 facing the positive direction of the magnetic tape 42 is adjusted to adjust the perpendicularity of the gap of the magnetic head 43 with respect to the tape center of the magnetic tape 42. When traveling in the forward direction, the cam plate head 50 slides in the direction of arrow R, causing the roller 56 to disengage from the cam 52 and, by a clockwise biased spring (not shown), pinch roller 39 shown in FIG.
is pressed against the capstan 38 via the magnetic tape 42. Then, the capstan 38 rotates counterclockwise, and the magnetic tape 42 runs in the forward direction, that is, in the direction of arrow F. On the other hand, the roller 57 for running in the reverse direction comes into contact with the cam 53, and the rotation of the pinch roller 41 for running in the reverse direction is restricted.

As the cam plate head 50 slides in the R direction, the end 511 of the cam hole 51 touches the sliding plate 7.
0 sliding pin 71 in the R direction. Therefore, the sliding plate 70 also slides in the R direction. At this time, the rollers 68 and 69 inserted into the roller insertion holes 74 and 75 of the sliding plate 70 also move while rotating in the R direction. Even if the sliding plate 70 slides in the R direction, it stops at the position where the pin 65 of the base head 60 abuts the long groove 72 of the sliding plate 70. At this time, the roller 68 rides on the base 67 and the adjustment screw 85 of the holding plate 84
Push the sides upwards. Adjustment screw 8 of retaining plate 84
When the 5th side is pushed upward, the adjustment table 83 is also pushed up along the fixed guide pin 63 and the guide pin 64 by the amount adjusted by the adjustment screw 85. The adjustment table 83 pushes up the other end of the base plate 81 against the head pressing spring 82. Therefore,
The adjustment table 83 moves up and down, but the base plate 81 uses one end as a fulcrum and the other end rotates. By turning the adjustment screw 85 in this state, the perpendicularity of the gap of the magnetic head 43 with respect to the tape center when the magnetic tape 42 is running in the forward direction can be adjusted.

Next, azimuth adjustment when the magnetic tape 42 runs in the reverse direction will be explained. When traveling in the reverse direction, the cam plate head 50 slides in the direction of arrow F. Then, the roller 57 comes off the cam 53,
The pinch roller 41 shown in FIG.
2 to the capstan 40. Therefore, the capstan 40 rotates clockwise, and the magnetic tape 42 runs in the opposite direction, that is, in the direction of arrow R. On the other hand, the roller 56 comes into contact with the cam 52, and rotation of the pinch roller 39 for forward travel is restricted.

As the cam plate head 50 slides in the F direction, the end 512 of the cam hole 51 pushes the sliding pin 71 in the F direction. Therefore, the sliding plate 70
slide in the direction. At this time, the rollers 68 inserted into the roller insertion holes 74 and 75 of the sliding plate 70,
69 also moves while rotating in the F direction. and,
The roller 69 rides on the base 67 and the holding plate 84
Push up the adjusting screw 86 side. Holding plate 8
When the adjustment screw 85 side of No. 4 is pushed upward,
The adjustment screw 86 and adjustment stand 83 are also pushed upward. The adjustment table 83 pushes up the other end of the base plate 81 against the head pressing spring 82. By turning the adjusting screw 86 in this state, the verticality of the gap of the magnetic head 43 with respect to the tape center when the magnetic tape 42 runs in the reverse direction can be adjusted.

As mentioned above, in this embodiment, the magnetic tape 4
The adjustment table 83 is moved up and down along the fixed guide pin 63 and the guide pin 64 according to the traveling direction of the head 2, so that one end of the adjustment table 83 pushes up the other end of the base plate 81 fixed to the head fixing pin 62. So,
The other end of the base plate 81 rotates around one end,
Since the adjustment screws 85 and 86 screwed into the adjustment table 83 only move up and down and no rotational force is applied, the adjusted azimuth angle will not be distorted.

〔Effect of the invention〕

As described above, according to the present invention, one end of the support to which the magnetic head is attached is fixed, the other end is pushed down by elastic force, and one end of the support is fixed.
The adjusting member with which the pair of adjusting screws are screwed is brought into contact with the lower surface of the other end of the support, and the sliding body is slid according to the running direction of the magnetic tape so that either one of the pair of adjusting screws is screwed together. The azimuth angle of the magnetic head can be adjusted in accordance with the running direction of the magnetic tape by bringing it into contact and pushing it upward, and pushing up the other end of the support via the adjustment member. Therefore, the azimuth can be easily adjusted in accordance with the running direction of the magnetic tape by simply adjusting the adjustment screw on the side facing the running direction of the magnetic tape. Moreover, the sliding body slides in the horizontal direction,
Since the adjustment member and the other end of the support body only move in the vertical direction, no rotational force is applied to the adjustment screw, so that the adjusted azimuth angle will not be distorted.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the overall configuration of a car stereo to which an embodiment of the present invention is applied. FIG. 2 is an exploded perspective view of one embodiment of the present invention. FIG. 3 is an external view of the sliding plate included in FIG. 1. Fourth
The figure is a longitudinal sectional view of an embodiment of the present invention. Fifth
The figure is a plan view of the head adjustment mechanism when the magnetic tape is running in the forward direction. FIG. 6 is also a front view. FIG. 7 is a plan view of the head adjustment mechanism when the magnetic tape is running in the reverse direction. FIG. 8 is also a front view. FIG. 9 is an external perspective view of the main part of a conventional magnetic head azimuth adjustment device. FIG. 10 is also a sectional view of the main part. In the figure, 42 is a magnetic tape, 43 is a magnetic head, 50 is a cam plate head, 51 is a cam hole, 60 is a base head, 62 is a head fixing pin, 63 is a fixed guide pin, 64 is a guide pin,
65 and 66 are pins, 67 is a base, 68 and 69 are rollers, 70 is a sliding plate, 71 is a sliding pin, 72 is a long groove, 73 is an oblong hole, 74 and 75 are roller insertion holes,
80 is a head support body, 81 is a base plate, 82 is a head pressing spring, 83 is an adjustment table, 84 is a holding plate, 85,
86 indicates an adjustment screw.

Claims (1)

[Scope of Claims] 1. A head adjustment mechanism for adjusting the azimuth angle of a magnetic head according to the running direction of a magnetic tape, one end of which is fixed, and the magnetic head is attached to the center of the mechanism, A support whose other end side is pushed down by elastic force so that the other end side moves up and down, and which is movable only in one direction in the up and down direction with respect to the tape width direction and whose upper surface is an adjustment member provided so as to come into contact with the lower surface of the other end of the support; a guide member provided in association with the adjustment member and serving as a guide when the adjustment member moves up and down; a guide member screwed onto the adjustment member; a pair of adjustment screws for adjusting the azimuth angle of the magnetic head according to the running direction of the magnetic tape by moving the adjustment member up and down; and a lower part of the pair of adjustment screws that is slidable in the horizontal direction. a sliding body for moving the adjusting member up and down by coming into contact with the lower part of one of the pair of adjustment screws based on the sliding movement of the sliding body, and according to the sliding movement of the sliding body, A head adjustment mechanism for adjusting an azimuth angle of the magnetic head by pushing up one of the pair of adjustment screws, thereby pushing up the other end of the support body through the adjustment member. . 2. A pair of the guide members are provided along the running direction of the magnetic tape, and the adjustment member is configured to move up and down only in one direction in the up and down direction with respect to the tape width direction along the pair of guide members. A head adjustment mechanism according to claim 1.