JPS61222016A - Azimuth adjusting mechanism - Google Patents

Abstract

PURPOSE:To realize two azimuth angles in one magnetic head by moving an azimuth adjusting screw abutting part in interlocking with a tape running direction changeover lever, and using said abutting part to provide a reference height to the adjusting screw. CONSTITUTION:The azimuth adjusting screws 8, 9 attain separate azimuth adjustment in different tape running directions. In turning the screw 8 in a state shown in figure, the azimuth adjustment in e tape running direction (right direction) according to the tape running direction changeover lever 12 in this state is attained. The adjustment is performed while a peak in the reproducing frequency characteristic is caused. When the lever 12 is switched and the screw contact part 15 comes under the screw 9, the screw 9 is used to provide a peak in the reproducing frequency characteristic. The tape running direction is opposite to that by the screw 8. Thus, the screws 8, 9 apply adjustment respectively to the azimuth angle in the forward/reverse running direction. After the adjustment, the signal if reproduced automatically at the best point in matching with the movement of the lever 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an azimuth adjustment mechanism for an auto-reverse type cassette deck.

[Conventional technology]

The angle between the magnetic head and the magnetic tape (azimuth angle) affects the reproduction frequency characteristics, and there is an optimal azimuth angle. However, this is the case when the tape runs in the same direction, and in an auto-reverse type that handles forward and reverse runs using the same head, the best point for re-running generally does not match.

FIG. 3 shows a typical example of a conventional azimuth adjustment mechanism, in which 31 is a magnetic head, 32 is a head support base on which it is mounted, 33 is a head mount for moving the head 31, 34 is a spacer,
35 is a head fixing screw that fixes one end of the head support 32 to the head mount 33 using the spacer 34;
Reference numeral 6 denotes an azimuth adjustment screw that uses a helical spring 37 instead of a fixed length spacer to adjust the height of the other end of the head support base 32. When the inclination of the support base 32 changes depending on the amount of engagement of the azimuth adjustment screw 36, the angle formed between the head 31 and the magnetic tape 38 also changes.

[Problem that the invention seeks to solve]

However, in the auto-reverse type in which the tape 38 runs not only in the forward direction F but also in the reverse direction R, the peaks of the reproduction frequency characteristic level in each running direction occur at different azimuth angles θF and θR, as shown in FIG. is common. Therefore, conventionally, the adjustment is made to the midpoint θM, which has the disadvantage that neither of them is at the best level (Δ
L is the level difference from the peak). Moreover, finding this intermediate point requires changing the tape running, which results in extremely poor work efficiency.

The present invention seeks to improve these points.

[Means for solving problems]

The present invention relates to an azimuth adjustment mechanism for an auto-reverse type cassette deck that reproduces signals from magnetic tapes running in different running directions using a common magnetic head. A mechanism that supports the holder in a rotatable manner, two azimuth adjustment screws that are screwed onto the other end of the holder to define the inclination of the holder, and a screw contact section that moves in conjunction with the tape running direction switching lever. and an azimuth cam that provides a reference height to one of the two azimuth adjustment screws by the screw contact portion.

[Effect]

Two azimuth adjustment screws that can be adjusted individually are provided, which are screwed into the head holder, and an azimuth cam is provided that moves the screw contact part in conjunction with the tape running direction switching lever. By giving a reference height to the azimuth adjustment screw (the other is unsupported), two azimuth angles can be achieved with one head. This will be explained in detail below with reference to illustrated embodiments.

〔Example〕

FIG. 1 is a configuration diagram showing an embodiment of the present invention, and FIG. 2 is a detailed diagram of each part thereof. In FIG. 1, 1 is a magnetic head, 2 is a head support base on which it is mounted, 3 is a head mount for moving the helad 1 forward or backward, and 7 is a head to which the head support base 2 is attached with screws 24 and 25. It is a holder.

This head holder 7 is elastically supported by the head mount 3 in the vertical direction.

That is, the left end is pressed from above by the L-shaped leaf spring 5. 23 is a screw for fixing this plate spring 5, 21
is a spacer. However, if the lower surface of the holder 7 is brought into direct contact with the head frame 3, the azimuth adjustment can only be made upwards, so a spherical head rotation fulcrum (dowel) 22 is formed on the lower left surface of the holder 7 so that the holder 7 is centered on the left end. to be able to rotate up and down. Therefore, this part 5.21.2
2.23 can also be realized with other pivot mechanisms.

On the other hand, the right end of the holder 7 is always pressed from above by a helical spring (head bias spring) 19. This spring 1
9 is supported by a screw 20 screwed into the upper part of a fixed shaft 20' fixed to the head frame 3. FIG. 2(d) shows this part enlarged. However, the holder 7 has a fixed shaft 20'.
Since a through hole is formed to pass through the head, the right end thereof will tend to rotate toward the head mount 3 if there is no member to support it from below. The two azimuth adjustment screws 8 and 9 and the azimuth cam 4 are used to appropriately prevent this movement and adjust the inclination of the head 1, and thus the azimuth angle.

The screw 8.9 is screwed into the holder 7 and causes its tip to protrude downward. 10.11 is a spring that locks the protruding length of this screw 8.9 to maintain the azimuth adjustment angle.

The azimuth cam 4 rotates on the head mount 3.

Its rotating shaft is the aforementioned fixed shaft 20', and the driving force is applied from the tape running direction switching lever 12. 26 is a shaft protruding from the lower surface of the cam 4 for linking with the switching lever 12. Reference numeral 15 denotes a screw contact portion that moves below the screw 8.9 when the cam 4 rotates. This is a part of the cam 4 that protrudes upward. The leaf spring 6 is an intervention that allows the screw abutment 15 to easily slide below the spaced screws 8.9.

In the above arrangement, the screws 8.9 allow separate azimuth adjustments for different tape running directions. In other words,
By rotating the screw 8 in the illustrated state, the azimuth can be adjusted in the tape running direction (rightward direction) according to the state of the switching lever 12 at this time. This adjustment may be made to bring out the peak of the reproduction frequency characteristics. And the switching lever 1
2 and when the screw contact portion 15 is positioned below the screw 9, the screw 9 is adjusted so as to produce the peak of the reproduction frequency characteristic. At this time, the tape running direction is opposite to that of the screw 8. Therefore, as explained using the characteristic diagram of FIG. 4, the screws 8 and 9 are adjusted to produce the azimuth angles θF and θR, respectively. After this adjustment, the cam 4 rotates in accordance with the movement of the switching lever 2, so that regeneration is automatically performed at the best point.

The operating principle of the present invention has been described above, and the details of each part will be explained next. First, the leaf spring 6 has the shape shown in FIG. 1), and although a portion thereof is engaged with the holder 7, it is basically in a free state. Therefore, the fixed shaft 20' also passes through the through hole of the leaf spring 6. The shaft 26 of the azimuth cam 4 passes through the long hole 27 of the head mount 3 and engages with the switching lever 12. In addition to the elongated hole 27, the head mount 3 is provided with two locking holes 16, 16 and a threaded hole 28 into which the screw 20 is screwed, as shown in FIG. 2(a).

The azimuth cam 4 has a through hole 29 through which the screw 20 passes, as shown in FIG. A holder rising part 17 having a trapezoidal cross section higher than the part 15 is provided, and the holder rising part 17 absorbs the force of the spring 19 when the cam 4 rotates when the screw contact part 15 is not located below the screw 8 or 9. This is to prevent wear of the contact portion 15 and the screw 8 or 9. In order to make this effect more noticeable, the dowel 18 is also made to protrude downward from the holder 7. That is, when the cam 4 rotates, Then, the dowel 18 rides on the holder rising part 17 and the holder 7 rises.As the screws 8 and 9 also rise accordingly, the contact between the screws 8 or 9 and the plate spring 6 is lost, and the contact with the screw contact part 15 is The pressing force of the leaf spring 6 also weakens.Soon, when the cam 4 rotates to a predetermined position,
The dowel 8 is removed from the holder rising part 17 and the holder 7 is lowered. As screws 8 and 9 also descend accordingly, screw 8
Or 9 contacts the leaf spring 6 while facing the screw contact portion 15 . In this way, when the cam 4 rotates, the lower ends of the screws 8 and 9 do not come into contact with anything, and the pressing force of the leaf spring 6 against the screw contact portion 15 is also weakened, so that the screw contact portion 15 and the screw 8 or 9 are not in contact with each other. can prevent wear. The second is a cam stopper pin (or Bearing) 13
is housed in the vertically long cylindrical part 30, and the tip of the pin 13 is placed in the second
Locking holes 16 and 16 in the head mount 3 shown in Figure (a)
The point is that it is made to engage with either one of the two. However, the head of the pin 13 is hemispherical, and its diameter is larger than the hole 16.

〔Effect of the invention〕

As described above, according to the present invention, the azimuth angle of the auto-reverse type cassette deck can be adjusted to the best point in any direction of travel, making it possible to make maximum use of the playback frequency characteristics of the head and to adjust the azimuth angle individually. Therefore, it has the advantage of good workability.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an embodiment of the present invention, Fig. 2 is a detailed view of each part thereof, Fig. 3 is a structural diagram of a conventional azimuth adjustment mechanism, and Fig. 4 is a reproduction frequency characteristic of an auto-reverse type cassette deck. and azimuth angle. In the figure, 1 is a magnetic head, 3 is a head mount, 4 is an azimuth cam, 6 is a leaf spring, 7 is a head holder, 5.21 to 23
1 is a mechanism for rotatably supporting one end of the holder 7; 8 and 9 are azimuth adjustment screws; 19 is a holder pressing spring; 12 is a tape running direction switching lever; and 15 is a screw contact portion. Applicant Fujitsu Ten Ltd. Representative Patent Attorney Minoru Aoyagi Embodiment of the present invention Figure 1 (C) Side view of the 7-piece 7-strain ram Figure 1 (2) 8N-1-Figure IIZ diagram

Claims (1)

[Claims] In the azimuth adjustment mechanism of an auto-reverse type cassette deck that reproduces signals from magnetic tapes running in different running directions using a common magnetic head, a head holder equipped with the magnetic head and one end of the holder are rotatable relative to the head mount. a supporting mechanism, two azimuth adjustment screws that are screwed onto the other end of the holder to define the inclination of the holder, and a screw contact portion that moves in conjunction with a tape running direction switching lever;
An azimuth adjustment mechanism characterized in that one of the two azimuth adjustment screws is provided with an azimuth cam that provides a reference height by the screw contact portion.