JPH0237620B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a magnetic recording medium used in a cassette-type video tape recorder (hereinafter referred to as VTR), etc., in which a magnetic tape wound in a cassette is pulled out and wound around a cylinder, and recorded and reproduced using a rotating head or the like. The present invention relates to a positioning mechanism of a recording/reproducing device.

As mentioned above, the operation of winding the magnetic tape in the cassette around the cylinder is called loading (similarly, the operation of returning the magnetic tape wound around the cylinder to the cassette is called unloading), but this loading mechanism has a large number of parts, and The total volume is also considerably larger, and in order to constantly promote smaller, lighter, and cheaper VTRs, the loading mechanism has been made smaller,
Simplification was an important point. Furthermore, when the tape is wound around a drawer cylinder using a post, there is a high probability that the space through which the post passes during the loading process will eventually become a dead space, which poses many problems in terms of efficient configuration of the device. It was. Furthermore, in order to pull out the tape, it is necessary to insert a post into the cassette through an opening provided in the cassette, and in order to make the cassette more compact, it is strongly desired that the loading mechanism be made more compact. Ta. Therefore, a method to solve the above problem can be considered by changing the position of the post when it is in the cassette and when giving the final tape pass with respect to the ring that is the means for moving the post. However, this method has the problem that with a small and simple configuration, it is difficult to position the post with a small error in relation to the ideal position and with a repeatability that guarantees the same position no matter how many times it is repeated.

The present invention has been devised to solve a number of such problems, and provides a small and simple positioning mechanism that enables a highly efficient, compact and lightweight loading mechanism that can form a predetermined tape path. It provides: DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to facilitate understanding of embodiments of the present invention, description will be given below based on reference figures shown in FIGS. 1 to 11. First, FIG. 1, which shows a schematic configuration of the entire apparatus, will be explained. Rotation is transmitted from a capstan motor 2 on a substrate 1 to a capstan 5 via a motor pulley 2a, a belt 3, and a flywheel 4. The pinch roller 6 is pressed against the capstan 5 only in the "record" and "reproduction" modes as shown by the two-dot chain line when the arm 7 engages with a mode conversion plate (not shown). As a result, the capstan 5 and the pinch roller 6
The magnetic tape 21 sandwiched between the two runs at a constant speed. At this time, the tape 21 comes into contact with the running post 8 and runs stably. Now, such running is all done in a predetermined tape path, but the tape is wound around the take-up reel 10 and the supply reel 11 in the cassette 9, and is stretched over the front surface of the cassette 9 via the posts 32a and 32b. The second section describes the loading mechanism for setting the tape 21 to a predetermined tape path.
This will be explained with reference to FIGS. When the cassette 9 is mounted on the board 1, the main post 26 and sub-posts 27, 28, 29 enter into the opening 34 on the front surface of the cassette 9 as shown in the figure. The main post 26 is held on a main post stand 56, and the main post stand 56 is coupled to a hooker 59 via a coupling arm 58 fitted to a shaft 60. The hooker 59 is fixed on the main ring 15, and the main post 26 follows the rotation of the main ring 15. Furthermore, since the grip 57 fixed to the main post base 56 engages with the guide ring 64, the main post 26 changes its position according to the shape of the guide ring 64 as the main ring 15 rotates. It is. This guide ring 64 is held by a plurality of supports 63 and is arranged around the cylinder 22 to move the main post 26 from the opening 34 to the main stopper 62. The position of the main post 26 after loading is shown by the two-dot chain line in FIG. Deputy post 27,2
8 and 29 are each held at a predetermined angle of inclination on the sub-post stand 54. This sub-post stand 54 is mounted on the sub-ring 16 with a presser plate 55 on the lower side of the sub-ring 16.
It is placed so as to sandwich the sub-ring 16 between the two, and is configured to be slightly movable on the sub-ring 16, but the details will be described later. In order to absorb the backlash caused by this movement, the pin 1 stands up on the sub-ring 16.
A spring 14 is hooked between the pin 13 standing up on the sub-post stand 54 and the sub-post stand 54, and the sub-post stand 54 is biased to the left in FIG. In this way, the sub-posts 27, 28, 29 are loaded to the position indicated by the two-dot chain line in FIG. 1 by the rotation of the sub-ring 16.
The details of the sub-stopper 23 and the positioning post 24 will be described later. Now, the main ring 15 and the sub-ring 16 each have a gear-shaped outer periphery, and the main ring 15 has a gear 20 and the sub-ring 16 has a gear 19.
They mesh with each other. Further, the gears 19 and 20 are coaxial and rotate integrally, that is, at the same angular velocity, and constitute the drive gear 18. Note that the driving force transmission path from the loading motor to the driving gear 18 is not shown. Reference numeral 17 denotes a main and sub-ring support gear consisting of two gear parts having the same shape as the two gears 19 and 20 of the drive gear 18. By these two ring support gears 17 and drive gear 18, the main ring 15
And the sub-ring 16 can have the same rotation center. As can be seen from FIG. 1, there is a diameter difference between the gear 19 and the gear 20, and there is also a diameter difference between the gear portions formed on the outer peripheries of the two main and sub-rings 15 and 16 so as to mesh with the gear 19 and the gear 20. exist. Now, the two gears 19 and 20 of the drive gear 18 rotate at the same angular velocity, so when they rotate in the direction of arrow A in Figure 1, the two main and secondary rings 15 and 16 rotate in the direction of arrow B in Figure 1 15 rotates faster than the sub-ring 16. Therefore, depending on how each gear is selected, the main post 26 and the sub posts 27, 2 depending on the loading time.
The distance between 8 and 29 can be set almost arbitrarily, and the tape path as in this embodiment can also be set. At this time, the main post 26 and the sub post 2
The final position of 7, 28, and 29 shown by the two-dot chain line in FIG. The positions of the main stopper 62, sub-stopper 23, and positioning post 24 are very important and require delicate adjustments. It is what you need. 2
5 is a tape position regulating post, 30 is a full-width erasing head, 31 is an audio erasing head, and 33 is an audio and control signal recording head. Although not shown in the drawings, two rotary heads for recording video signals are provided within the cylinder 22.

Next, based on Figures 4 and 5, the main post 26
The manner in which the position is determined will be explained. FIG. 4 shows the main stopper 62. The main stopper 62 is the V portion 35,
It has a U section 36 and is fixed to the substrate 1 through two holes 37a and 37b. As shown in FIG. 5, the main post stand 56 is pulled by the coupling arm 58 in accordance with the movement of the main ring 15, and the shape of the guide ring 64 guides the main post stand 56 to come into contact with the main stopper 62. At this time, the bearing portion 61 of the main post base 56 is fitted into the U portion 36 of the main stopper 62. The upper end 38 of the main post stand 56 is the main stopper 62
When it comes into contact with the V section 35 of the main post base 56, the connecting arm 58 is pulled in the lower right direction (in the direction of arrow G) in FIG. A moment is generated in the direction of arrow C). As a result, at the tip of the main post base 56, there was a gap between the V section 35 and the U section 36 due to the relief section 39, but the tip section 65 is located inside the V section 35. come into contact with The drawing shows this situation. The bottom surface of the main post stand 56 other than the bearing part 61 rests on both sides of the U section 36, and in this state, the main post stand 56 does not move no matter how much the coupling arm 58 pulls the main post stand 56.
That is, as long as there is a force of the coupling arm 58 in the lower right direction in FIG. 5 (in the direction of arrow G), the main post 26 is perfectly positioned. Furthermore, a certain degree of reproducibility can be obtained due to the dimensional accuracy of the main stopper 62 and the main post base 56, and this is a very effective positioning method for securing the final position of the main post 26.

Next, a method for positioning the sub-posts 27, 28, 29 and the sub-post stand 54 will be described based on FIG. 1 and FIGS. 6 to 11. In FIG.
0 and protrudes above the main ring 15 and sub-ring 16. The positioning post 24 is planted on the substrate 1. FIG. 6 shows the structure of the sub-post stand 54 and the sub-ring 16. Note that the sub-post stand 54 is shown in a simplified manner. Reference numeral 41 is a cam-shaped groove provided in the sub-ring 16 with one end 41a bent. Two protrusions 42 and 43 on the bottom of the sub-post base 54 fit into this groove 41, and the sub-ring 16 is pressed from below. Fasten with screws through the plate 55. This protrusion 4
The height of 2, 43 is slightly longer than the thickness of the sub-ring 16, and the diameter is slightly smaller than the width of the groove 41. That is, the sub-post stand 54 is guided by the projections 42, 43 and the groove 41 and can freely slide on the sub-ring 16. Now, in order to prevent this sliding, a spring 14 is hooked between the pin 12 that stands up on the sub ring 16 and the pin 13 that stands up on the sub post base 54, and the urging force of the spring 14 causes the protrusion 42 to become grooved. The protrusion 4 is brought to one end 41a of the 41
2, 43 and the shape of the groove 41, the sub-post stand 54 is located at a position as shown in FIG. Note that 44 is a convex portion projecting in an arc shape on the side of the sub-post stand 54;
It is fitted into a recess 45 of the sub-stopper 23 shown in FIG. Further, in FIG. 7, the direction of arrow D is the loading direction.

8a to 8c are diagrams showing the movement of the sub-post base 54 when sliding along the groove 41 described above. Now, consider a case where the sub-post stand 54 remains at substantially the same position and only the sub-ring 16 moves in the loading direction (direction of arrow D). FIG. 8a shows the same state as FIG. 7, and this is taken as the initial state. From this state, when only the sub ring 16 rotates in the loading direction (direction of arrow D) as described above, the spring 14 is stretched as shown in FIG. Related post stand 54
moves slightly counterclockwise, and then the sub ring 16
As the rotation progresses, the state as shown in FIG.
The movement of the sub-post stand 54 by sliding is eliminated. As a result, during the loading process, the sub-post stand 54 rotates on the sub-ring 16, that is, the position of each sub-post 27, 28, 29 relative to the sub-ring 16 can be changed. In other words, by selecting the shape of the groove 41 and the position of the protrusions 42, 43 on the sub-post base 54, the sub-posts 27, 28, 29 can be moved almost freely when setting the tape path and when located at the front opening 34 of the cassette 9. The position can be set, and the cassette 9 can be designed without worrying too much about the tape path. FIG. 9 is a diagram showing the configuration of the sub-stopper 23, and as described above, the sub-stopper 23 is held below the substrate 1.
A support plate 46 is fixed under the substrate 1 from the back side. Two shafts 47 and 48 are installed in this support plate 46, and holes 5 provided in the sub-stopper 23
0 is fitted onto the shaft 47, and is also regulated in the vertical direction. Therefore, the sub-stopper 23 can rotate around the shaft 47, and has one degree of freedom. Further, a spring 52 is hung between the protrusion 51 of the sub-stopper 23 and the cut-and-raised portion 49 of the support plate 46.
Turn the sub-stopper 23 clockwise (direction of arrow F in Figure 9)
to energize. Then, another protrusion 53 of the sub-stopper 23 comes into contact with the shaft 48 set on the support plate 46, and in this state, the position of the sub-stopper 23 is determined. FIG. 10 shows the attached state of the sub-stopper 23 viewed from above, but the substrate 1 is omitted for convenience. The convex portion 44 of the sub-post base 54 mentioned above enters the concave portion 45 of the sub-stopper 23 from the direction of arrow E in FIG. In other words, the arc of the concave portion 45 corresponds to the convex portion 4.
It is equal to that of 4.

The movement of the sub-stopper 23 and the sub-post stand 54 will be explained with reference to FIGS. 11a to 11c. First, as loading progresses, the sub-post stand 54 approaches the sub-stopper 23. FIG. 11a shows this state. The sub-stopper 23 is held at an angle such that the protrusion 44 of the sub-post stand 54 can easily fit into the recess 45 of the sub-stopper 23. FIG. 11b shows a state in which the loading progresses further and the above-mentioned convex portion 44 is completely accommodated in the concave portion 45. At this time, the main post 26 is also connected to the main stopper 62.
has not yet been reached, and the main ring 15 and the sub-ring 16 will rotate a little further. Loading ends when the main post 26 is completely positioned by the main stopper 62 (the ring cannot move any further), so just before the end of loading, the sub posts 27, 28, and 29 are in the vicinity of their normal positions. This means that we have reached this point. Now, although the sub-post stand 54 is prevented from moving forward by the sub-stopper 23, only the sub-ring 16 continues to rotate for the remaining loading time. The table 54 attempts to rotate counterclockwise (in this case, in the direction of arrow J in FIG. 11b). Further, as explained in FIGS. 9 and 10, the sub-stopper 23 is moved around the shaft 47 by the arrow J.
Rotation in this direction is possible against the biasing force of the spring 52. Here, when the rotation center of the sub-post base 54 due to the shape of the groove 41 and the axis 47 coincide with each other, and the elastic force of the spring 14 is stronger than the elastic force of the spring 52, the sub-post base 54 and The sub stopper 23 rotates in the direction of arrow J as a unit. After rotation to a certain extent, the sub stopper 23 comes into contact with the positioning post 24, and further rotation becomes impossible.
This state is shown in FIG. 11c. In this case, it is necessary to allow some allowance for the groove 41 of the sub-ring 16. That is, for positioning, the purpose is to give the sub-stopper 23 and the positioning post 24 the precision necessary to realize a predetermined tape path, and to ensure that the sub-ring 16 can sufficiently achieve its purpose even if it moves somewhat roughly. Immediately after this state is created, the main post 26 is positioned and the loading is completed. However, in order to maintain the tape path, it is necessary to secure the final position of each post, and a force must always be applied to the main ring 15 and the sub-ring 16 in the loading direction.

Unloading can be performed by rotating the drive gear 18 in the reverse direction. Regarding the movement of the sub-post stand 54, the above-described events occur in the completely reverse order, and when it finally returns to the cassette 9, it returns to the exact same state as before loading. The relationship between the main and sub-two rings 15 and 16 is determined digitally by gear engagement, and will never change no matter how many times loading and unloading is repeated.

Next, an embodiment of the present invention in which the post stand is rotated relative to the ring will be described based on FIGS. 12 to 14. Reference numeral 66 denotes a block corresponding to the above-mentioned sub-post stand 54. A gear 67 is fixed to the bottom of this block 66, and a hole 68 is formed in the center. Reference numeral 69 denotes a ring corresponding to the sub-ring 16, and a spring 72 is hung between a pin 70 that stands up on this ring 69 and a protrusion 71 on the front surface of the block 66, and the block 66 is attached in the direction of arrow K in FIG. Forced. A gear portion 73 is provided on the surface of the ring 69. The block 66 is held slidably on the ring 69 by inserting the shaft 74 into the hole 68 through the groove 75 of the ring 69. Further, the gear 67 is configured to mesh with the gear portion 73, and this state is shown in FIG. 13 when viewed from above. Now, as described above, when the block 66 is prevented from moving forward in the loading direction in the direction of arrow K in FIG. 13 in the direction of arrow M]. At this time, the groove 75 is
Despite the rotation of 9, the gear 67 and the gear portion 73
It is necessary to form a shape that maintains the same pitch circle distance. Since the gear 67 and the block 66 are integrated, the block 66 naturally also rotates in the direction of arrow M in FIG. 13, resulting in the state shown in FIG. 14. In this case, positioning can be performed using a stopper similar to the above example.

There is also the idea of not taking the trouble to rotate the sub-stopper 23 and simply abutting the sub-post base 54 and allowing it to slide during rotation, but this tends to cause the load to increase due to prying, and the motor torque must also be increased. This will lead to undesirable results for the entire device.

The positioning mechanism of the magnetic recording and reproducing apparatus of the present invention can be implemented as described above, and a small, simple, and reliable positioning mechanism has been obtained.
The following effects can be obtained.

The loading mechanism uses gears to operate very reliably and stably, and is miniaturized with a simple configuration. [At least one of the tape pull-out members, for example, the sub-post, can be moved in the most compact state, that is, with the minimum required passing area, until just before it is positioned, and no other parts are particularly required. ] The cassette becomes smaller. [The area required for posts inserted into the front of the cassette can be minimized.

As a result, the entire device also becomes smaller and, inevitably, lighter.

Therefore, according to the present invention, it is inevitable that the present invention will be greatly improved compared to the prior art, and the usability of the VTR will be improved and further development will be possible.

[Brief explanation of drawings]

Figures 1 to 11 are provided to facilitate understanding of the embodiments of the present invention. Figure 1 is a schematic configuration diagram of a VTR, Figure 2 is a configuration diagram of a tape drawer post of the same VTR, and Figure 3 is an explanatory diagram of the main post stand of the VTR, Figure 4 is a perspective view of the main stopper of the VTR, Figure 5 is an explanatory diagram of the main post positioning state of the VTR,
Fig. 6 is an exploded perspective view of the sub post stand mounting part of the VTR, Fig. 7 is a plan view of the sub post stand mounting part of the VTR, and Figs. 8 a to c are explanatory diagrams of the sub post stand operation of the VTR. Fig. 9 is an exploded perspective view of the sub-stopper mounting part of the same VTR, Fig. 10 is a plan view of the sub-stopper mounting part of the same VTR, Figs. The figure is an exploded perspective view of the post base mounting part in one embodiment of the present invention, the first
3 and 14 are explanatory diagrams of the operation of the post stand. 1... Board, 9... Cassette, 15... Main ring, 1
6... Sub-ring, 21... Magnetic tape, 22... Cylinder, 23... Sub-stopper, 24... Positioning post,
26...Main post, 27, 28, 29...Secondary post,
54... Sub post stand, 56... Main post stand, 65... Main stopper, 66... Block, 69... Ring.

Claims (1)

[Claims] 1. A guide drum 22 with a built-in rotating head,
A plurality of tape pull-out members 27, 28, 29 which pull out the magnetic tape 21 wound inside the cassette 9 to the outside of the cassette 9 and wrap it around the guide drum 22 to form a part of a predetermined tape path, It consists of a rotating ring 69 for transferring the members 27, 28, 29 to predetermined positions, and a stopper member 23 for locking the tape pulling members 27, 28, 29, and the rotating ring 69 has a gear-shaped part. 73 and a groove portion 75, a gear portion 67 that meshes with the gear-shaped portion 73 is integrally formed on at least one of the tape pull-out members 27, 28, and 29, and The rotating ring 69 is engaged while being biased in the direction.
At least one of the tape pull-out members 27, 28, and 29 engaged with the groove portion 75 is locked by the stopper member 23 immediately before the tape pull-out members 27, 28, and 29 rotate to form a part of a predetermined tape path, and the rotation is stopped. By only the ring 69 continuing to rotate against the elastic force, the engagement position between the groove 75 and at least one of the tape pull-out members 27, 28, 29 engaged with the groove 75 is established. As the gear part 67 meshes with the gear-shaped part 73 rotates, at least one of the tape pull-out members 27, 28, and 29 that is engaged with the groove part 75 moves into the rotation ring 69. A positioning mechanism of a magnetic recording/reproducing device configured to rotate on the top to form a part of a predetermined tape path.