JPS63181150A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To set a back tension separately to a rotary cylinder and an A/C head by providing a 2nd tension post providing the back tension to the audio control A/C head and varying the winding angle of a magnetic tape onto the post. CONSTITUTION:The magnetic tape 15 is pressed into contact with the 2nd tension post 1 with a winding angle of theta. In moving the position plate 5 of a positioning shaft 4 of the 2nd tension post 1 in the direction A, the winding angle theta to the magnetic tape 15 is larger than the back tension T3' of the A/C head 10 is increased. In moving the positioning plate 5 in the direction B, the winding angle theta onto the magnetic tape 15 is smaller and the back tension T3' of the A/C head 10 is decreased. Thus, the 2nd tension post 1 is provided before the A/C head 10 and the means varying the winding angle of the magnetic tape onto the 2nd tension post 1 is provided so as to set the back tension of the rotary cylinder and the back tension of the A/C head 10 separately.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a magnetic recording/reproducing device.

2. Description of the Related Art A conventional magnetic recording and reproducing apparatus will be explained with reference to FIG. FIG. 4 is a schematic diagram showing the tape running system of a conventional video tape recorder (hereinafter referred to as VTR). In Fig. 4, 9 is an audio erase head, 1o is an audio control head (hereinafter referred to as A/C head), 11 is an A/C head mounting plate, 12 is a rotation shaft, 1
3 is a capstan shaft, 14 is a pinch roller, 15 is a magnetic tape, 16, 17, 25, 26 are fixed posts, 18 is a first tension post, 19 is a full erase head,
20, 21, 23, 24 are tape drawer posts, 22
is a rotating shilling, 27.28 is a reel stand, 29 ham
1 is the tension post lever, 30 is the first tension spring.

The operation of the conventional magnetic recording/reproducing apparatus configured as described above will be described below.

When loading the tape, the tape pull-out post 20,
21, 23, and 24 move from the position shown by the dashed line to the position shown by the solid line, and wind the magnetic tape 15 around the cylinder 22. The magnetic tape 15 is driven in the C direction by a capstan shaft 13 and a pinch roller 14. At this time, it is necessary to apply a certain back tension to the magnetic tape 15.

In the conventional VTR, as shown in FIG. 6, by applying a back tension of T to the tension run post 18 by a tension spring 3o, the /< tension T2 of the cylinder 22 and the back tension T of the A/C head 10 are adjusted.
I got 3. In the conventional running system, when the magnetic tape is driven in the C direction, T = a-T (IL>1) T3 = a-b
-T, (a, t+)1) is established, and by determining the bank tension T1, the back tension T21''5
was given by the above formula.

Problems to be Solved by the Invention However, with the above configuration, the back tension T2 of the cylinder 22 and the back tension T3 of the input/C head 10 cannot be set arbitrarily. Conventionally, T was set to make the back tension T2 of the cylinder 22 a constant value, but the back tension T3 of the input/C head 10 was not set arbitrarily.
By using a VTR for a long time, the mechanical load on the running system increases, the back tension T3 of the input/C head 10 increases, and magnetic powder from the magnetic tape tends to adhere to the input/C head 1o. There was a problem in that the head 10 suffered from increased wear.

In view of the above problems, the present invention provides a second tension post in front of the input/C head 10, so that the back tension T2 of the rotary cylinder 220 and the back tension T3 of the A/C head 10 can be set separately. The present invention provides a recording/playback device.

Means for Solving the Problems In order to solve the above problems, the magnetic recording and reproducing apparatus of the present invention provides a first
By providing a second tension post that applies a back tension T to the input/C head, and changing the winding angle of the magnetic tape to the second tension post, the back tensicon T2 and the back tension It has a configuration in which the tension T3 can be set separately.

Effect of the Invention With the above-described configuration, the present invention prevents the back tension of the input/C head from increasing when the VTR is used for a long time, and reduces the adhesion of magnetic powder from the magnetic tape to the input/C head. Furthermore, wear of the input/C head can also be reduced.

EXAMPLES Below, a magnetic recording/reproducing apparatus of the present invention will be explained with reference to the drawings.

FIGS. 1 and 2 show schematic configuration diagrams of embodiments of the present invention. In Fig. 1, 1 is the second tension post, 2 is the second tension post lever, 3 is the rotation axis,
4 is a positioning shaft, 6 is a positioning plate, 6.7 is a screw, and 8 is a biasing spring. In FIG. 2, 9 is an audio erase head, 1o is an input/C head, and 11 is an input/C head mounting plate.

12 is a rotating shaft, 13 is a capstan shaft, 14 is a pinch roller, 15 is a magnetic tape, 16.17°25.26 is a fixed post, 18 is a first tension post, 19 is a full erase head, and 2o.

21, 23, and 24 are tape draw-out posts, 22 is a rotating cylinder, 27, 28 is a reel stand, 29 is a first tension post, and 30 is a first tension post spring.

The operation of the magnetic recording/reproducing apparatus configured as described above will be described below with reference to FIGS. 1, 2, and 3. As shown in FIG. 2, during tape loading, the tape pull-out posts 20, 21, 23, 24 move from the position shown by the dashed line to the position shown by the solid line. At this time, the magnetic tape 16 contacts the second tension post 1 as shown in FIG. 3, and the magnetic tape 15 contacts the second tension post 1 with a winding angle of θ. At this time, the tension before and after the second tension post 10 is generally given by T'=eμθ·T (μ is the coefficient of friction between the second tension post 1 and the magnetic tape 16). At this time, if the positioning plate 7 shown in FIG. 1 is moved in the entry direction, the second
The position 6-a of the positioning shaft 4 of the second tension post 1 in contact with the positioning plate 5 also moves in the input direction, and the winding angle θ of the second tension post 1 around the magnetic tape 16 increases, causing the input/output direction to increase. The back tension T3/ of the C head increases. Further, if the positioning plate 7 is moved in the direction B, the position 5-4 where it comes into contact with the positioning shaft of the second tensicom blast 1
The second tension post 1 also moves in the B direction, the winding angle θ of the second tension post 1 on the magnetic tape 16 becomes smaller, and the back tension of the input/C head causes / to become smaller.

As described above, according to this embodiment, the second tension post 1 is provided in front of the input/C head 1o, and means for changing the wrapping angle of the magnetic tape around the second tension post 1 is provided. Therefore, the back tension T2 of the rotary cylinder 22 and the back tension T3 of the input/C head 10 are
can be set separately.

Effects of the Invention As described above, according to the present invention, by setting the back tension of the rotary cylinder and the back tension of the fixed head separately, the back tension of the fixed head can be set, and the back tension that is optimal for the fixed head can be set. You can obtain the excellent effect of being able to always set the .

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a main part of a magnetic recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a plan view of a tape running system of the magnetic recording/reproducing apparatus according to the embodiment, and FIG. 3 is an explanation of the embodiment. FIG. 4 is an enlarged plan view of a tape running system of a conventional magnetic recording/reproducing apparatus, and FIG. 6 is an enlarged plan view of the same essential parts. 1...second tension post, 2...-second tension boss lever, 3...rotation shaft,
4... Positioning shaft, 6... Positioning plate, 6, 7... Screws. Name of agent: Patent attorney Toshio Nakao and 1 other person/°
-Second tensicom blast?・-%l tension boss lever 3・-concave! Power shaft 4 - Relaxed J1 Terminal 6 - I upright, fixed plate 4, 7 - Screw Fig. 3 15 - Sulfur tag No. 4rI! J 15- Reef Air Teig

Claims (1)

[Claims] a rotating cylinder carrying a rotating head; a tape loading means for attaching a magnetic tape to the rotating head; a first tension post applying back tension to the rotating head; a fixed head; applying back tension to the fixed head. A magnetic recording/reproducing apparatus comprising a second tension post, and means for changing a winding angle of the magnetic tape around the second tension post.