JPH0470694B2 - - Google Patents

Description

[Detailed description of the invention] The transfer apparatus of the present invention will be explained in the following order.

A. Field of industrial application B. Overview of the invention C. Prior art D. Problems to be solved by the invention (Figs. 4 and 5) E. Means for solving the problems F. Effect G. Example (Fig. 1) and Fig. 2) a transfer drum b air guide c air reservoir groove H Effects of the invention (industrial field of application) The present invention is a novel transfer device, particularly an air guide for a running tape running on a tape guide member. The present invention relates to a novel transfer device that performs transfer while pressing air against a tape guide member by blowing air from an air outlet.

(B. Summary of the Invention) The present invention provides a transfer device that performs transfer while pressing a running tape against a tape guide member using air blown from an air outlet of an air guide, in which air is applied to a wall surface facing the tape guide member of the air guide. By providing a reservoir groove, the pressing force of the air against the transferred portion of the running tape is increased, thereby reducing the gap between the transfer tape (hereinafter referred to as "mother tape") and the transferred tape (hereinafter referred to as "copy tape"). This aims to eliminate the positional deviation between the tapes and, in turn, prevent a drop in the level of the transfer signal due to demagnetization due to the positional deviation between the tapes.

(C. Prior Art) A transfer device that transfers video, audio, or other information magnetically recorded on one tape (mother tape) to another tape (copy tape) is described in, for example, Japanese Patent Laid-Open No. 137137/1983. something is known. This type of transfer device includes at least a transfer drum that guides the mother tape and the copy tape, and an air guide in which an air outlet is formed on a wall surface facing the outer circumferential surface of the transfer drum. are passed between an air guide and a transfer drum at high speed while overlapping each other, and the mother tape and copy tape are strongly pressed against the transfer drum by the air blown out from the air outlet of the air guide, thereby magnetically recording on the mother tape. The information is transferred onto copy tape. Generally, it is necessary for a bias magnetic field to be generated in the transfer section for the transfer, so a bias head that generates the bias magnetic field is installed, for example, in an air guide, and the bias head is used to transfer the mother tape and copy tape. A bias magnetic field of a predetermined strength is generated in the area.

(D Problems to be Solved by the Invention) By the way, in the above-described transfer device, a deviation in relative positional relationship occurs between the mother tape and the copy tape, and as a result, a certain signal is transferred to the copy tape. There was a problem in that signals from a portion of the mother tape where the transfer was made and another portion had a magnetic influence on the portion of the mother tape, preventing high-fidelity transfer. This issue will be explained in more detail.

That is, in a transfer device, it is necessary to increase the running speed of the tape in order to increase the transfer efficiency, and the running speed is actually extremely fast, several meters per second. Therefore, even if the running speeds of the mother tape and the copy tape are controlled by a running speed control servo, it is difficult to accurately control the running speeds, and a positional shift occurs between the two tapes. This is because the speed detection unit, winding motor, etc. that make up the servo mechanism have time constants, and it takes time, even if only slightly, for the speed to return to a predetermined speed after the speed fluctuates. This time delay may not cause a large deviation in the positional relationship between the tapes when the running speed is slow, but when the running speed is slow, it causes a positional shift that cannot be ignored. Therefore, the fourth
As shown in the figure, drive tape c is stacked on copy tape a and mother tape b, and drive tape c is
The mother tape b and the copy tape c are made to run by winding them using a drive motor (not shown), and the drive tape c and the transfer drum d, which rotates at a rotation speed such that the running speed and the circumferential speed of the drive tape c are equal to each other, make the mother tape b and the copy tape c. At the same time as feeding the drive tape c
The tape tension servo is performed separately on the supply side of the mother tape B and the copy tape A, and on the supply side and the take-up side of the mother tape B and the copy tape A, thereby minimizing tension fluctuations. In the drawings, e is an air guide, and f is a bias head provided inside the air guide e.

However, even with this arrangement, it is extremely difficult to prevent rapid tension fluctuations because the tension detection section, motor, etc. that make up the tension servo mechanism have a time constant, albeit a small one.
This tension variation causes a shift in the relative positional relationship between the mother tape b and the copy tape a.

By the way, such a positional shift causes the transfer portion T and the detachment portion U where the tapes a and b separate from the transfer drum d.
If the signal is transferred to a certain transferred area of the copy tape a, the transferred area of the mother tape b overlaps with another area of the mother tape b. As a result, the signal transferred to the copy tape a is magnetically influenced by a signal different from the transferred signal on the mother tape b.
Therefore, specifically, the transferred magnetic signal is demagnetized. This adverse effect from the mother tape b to the copy tape a may occur even in locations where no bias magnetic field is generated. This demagnetization inevitably causes a decrease in the output level of the magnetically recorded signal, and experiments have confirmed that the output level can decrease by as much as 2 dB.
Incidentally, FIG. 5A shows the RF signal wavelength at which no demagnetization occurs when a signal recorded by a VTR is transferred, and FIG. 5B shows the waveform of the RF signal at which demagnetization also occurs. As is clear from FIGS. A and B, demagnetization causes a non-negligible difference in the waveform of the RF signal.

The present invention has been made to solve these problems, and it prevents the relative positional deviation between the mother tape and the copy tape from occurring, and also prevents demagnetization caused by the positional deviation. The purpose of this method is to prevent the level of the transferred signal from decreasing as a result.

(E. Means for Solving Problems) In order to solve the above-mentioned problems, the transfer device of the present invention has an air blowing port extending from the air blowing port on the wall surface facing the tape running surface of the air guide toward the tape running direction side. It is provided with a communicating air reservoir groove.

(F Effect) According to the transfer device of the present invention, since there is an air trap groove on the side of the air outlet in the direction of the running tape, the tape can be transferred not only in the part corresponding to the air outlet but also in the part on the side in the direction of the running tape. It can be strongly pressed against the tape guide member. Therefore, it is possible to prevent positional deviations between the tapes due to tension fluctuations or the like in the transferred portions of the tapes. Therefore, it is possible to prevent the level of the transfer signal from decreasing due to demagnetization of the magnetic signal due to positional deviation between the tapes.

(G Embodiment) The transfer apparatus of the present invention will be described in detail below according to the illustrated embodiment.

1 and 2 show an example of the implementation of the transfer apparatus of the present invention.

(a Transfer Drum) In the drawings, 1 is a transfer drum, and 2 is an air guide having a wall surface 3 facing the outer peripheral surface of the transfer drum 1.

A copy tape 4, a mother tape 5,
The drive tapes 6 are inserted in an overlapping state. Specifically, the copy tape 4 is located on the transfer drum 1 side, the mother tape 5 is located on the air guide 2 side of the copy tape 4, and the drive tape 6 is located on the air guide 2 side of the copy tape 4. , are stretched across the outer circumferential surface of the transfer drum 1 between a special supply reel and a take-up reel (not shown), and are at a central angle α from the starting point S of contact with the outer circumferential surface of the transfer drum 1 to the separation point U. The tapes 4, 5, and 6 are pressed against the transfer drum 1 in the region O (O is the center of rotation of the transfer drum 1), and the opposing surfaces of the copy tape 4 and the mother tape 5 are brought into close contact with each other. The drive tape 6 is then wound onto a take-up reel rotated by a drive motor (not shown) and run at a predetermined speed. On the other hand, the transfer drum 1 is rotated by a motor (not shown) connected via a rotating shaft 7 at a rotational speed such that its peripheral speed is equal to the running speed of the tape. The copy tape 4 and the mother tape 5 are caused to run at a predetermined speed by the rotating transfer drum 1 and the running drive tape 6. The tension of the tapes 4 and 5 is maintained at a predetermined value by applying tension servo on the supply side and take-up side of the copy tape 4 and mother tape 5, respectively. Also, on the supply side of the drive tape 6, tension is controlled by a tension servo. In this way, consideration is given to minimizing fluctuations in the tension applied to the copy tape 4 and the mother tape 5. However, the tension detection part that constitutes the tension servo mechanism,
As mentioned above, since motors and the like have time constants, it is impossible to completely eliminate tension fluctuations.

Note that T is the central part of the area where the copy tape 4 and the transfer drum 1 are in close contact (the area from the adhesion start part S to the separation part U), and in that part T, as will be described later, the copy tape is removed from the mother tape 5. 4 is transferred. Therefore, this portion T will be referred to as a transfer portion.

(b Air Guide) The air guide 2 is composed of a base 8, a guide block 9 fixed on the base 8, and a cover plate 10 fixed on the guide block 9 by, for example, screws. 11 is a set screw, and 12 is a screw hole formed on the upper surface of the guide block 9 into which the set screw 11 is screwed.

One side of the guide block 9, that is, the side facing the transfer drum 1, is concavely curved when viewed from above, and the radius of curvature of the concave curved surface is slightly larger than the radius of the transfer drum 1. , this concave side surface constitutes the wall surface 3 of the air guide 2 that faces the outer peripheral surface of the transfer drum 1 . The wall surface 3 is opposed to the outer circumferential surface of the transfer drum 1, particularly the area from the contact start part S to the part slightly beyond the separation part U via the transfer part T.

Reference numeral 13 denotes an air chamber formed in the guide block 9 so as to hollow it out, and has a pentagonal shape consisting of a triangular part and a square part, and the top part of the triangular part is the central part of the wall surface 3. Opening in the vertical direction (direction of the rotation axis of the transfer drum 1)
A long air outlet 14 is formed in the air. The air outlet 14 is opposed to the transfer section T.

The upper and lower sides of the air chamber 13 are closed by the cover plate 10 and the base part 8, thereby forming a space through which air to be blown onto the transfer drum 1 flows. Reference numeral 15 denotes an air introduction hole extending from the side surface of the guide block 9 opposite to the wall surface 3 and opening into the air chamber 13. An air supply pipe (not shown) for supplying air for blowing is connected to the outer end of the air introduction hole 15.

A bias head 16 is disposed within the air chamber 13 and held by a head holding member 17, and is composed of a core 18 and an excitation coil 19, and a gap 20 of the core 18 is located approximately at the center of the air outlet 14. , and the transfer part T
It plays the role of generating a bias magnetic field of a predetermined strength. Therefore, the mother tape 5 and the copy tape 4 that are brought into close contact with each other are brought into close contact with each other very strongly by the strong air from the air outlet 14 at the transfer section T, and are also excited by the bias magnetic field. From mother tape 5 to copy tape 4 like
A transcription is made.

Bias head 1 inside the air chamber 13
The portion between the head holding member 6 and the inner wall surface of the air chamber 13 becomes a thin air guide gap 21, 21, and the air outlet 14
The function is to increase the pressure of the air blown out.

(c Air reservoir groove) 22 is an air reservoir groove formed in the wall surface 3 of the air guide 2, and is formed by thinly cutting the surface of the wall surface 3 in a region on the tape running direction side from the air outlet 14. . The air reservoir groove 22 communicates with the air outlet 14 and extends from the air outlet 14 to a portion corresponding to the detached portion U or its vicinity, and its width is narrower than the width of each of the tapes 4, 5, and 6. The upper and lower inner surfaces 23, 23 of the air trap groove 22 are located slightly inside than the positions corresponding to both side edges of the running tapes 4, 5, 6, and the depth is, for example,
It is set to about 0.2 to 0.3 mm. Therefore, of the air that passes through the air guide caps 21 and 21 and is blown out from the air outlet 14, most of the air that goes in the tape running direction is located in the air reservoir groove 2.
While being prevented from coming out upward and downward by the upper and lower inner surfaces 23, 23 of 2, the air advances on the bottom surface of the air reservoir groove 22, and then the terminal surface 24 of the air reservoir groove 22.
, the tape is blocked from progressing in the running direction, and the air pressure inside the air trap groove 22 becomes high, causing the running tape 4,
5 and 6 strongly against the outer peripheral surface of the transfer drum 1. Therefore, the running tapes 4, 5, and 6 are blown directly from the air outlet 14 to the transfer portion T, particularly on the area from the transfer portion T to the detachment portion U among the areas pressed against the outer peripheral surface of the transfer drum 1. It is pressed more strongly by the air and the high pressure air in the air reservoir groove 22. Therefore, even if some tension fluctuation occurs in the copy tape 4 or the mother tape 5, the relative positional relationship between the tapes 4 and 5 will not shift.

By the way, Figure 3 A and B are air outlet 1.
This is a comparison of the distribution of pressure on the outer peripheral surface of the transfer drum 1 due to the air blown out from the air guide 3 in the case where the air trap groove 22 is not provided on the wall surface 2 of the air guide 3 and the case where the air trap groove 22 is provided in the wall surface 2 of the air guide 3. Figure A shows the case where the air reservoir groove 22 is not provided, and Figure B shows the case where the air reservoir groove 22 is provided.
In the figure, the X-axis indicates the position in the tape running direction of the area where the tapes 4, 5, and 6 are in close contact with the outer peripheral surface of the transfer drum 1, and the Y-axis indicates the height (position in the vertical direction) of the area. (P indicates the center position in the height direction of the air outlet 14), and pressure is maintained on the Z axis.

As is clear from this figure, the air reservoir groove 22
If there is no pressure, as shown in FIG.
The pressure decreases rapidly as it moves away from the tape (in the direction opposite to the tape running direction). Therefore, it is not possible to effectively prevent the relative positional relationship from shifting due to tension fluctuations in the transferred portions of the tapes 4 and 5. However, in the transfer device provided with the air reservoir groove 22 as shown in FIGS. 1 and 2, the separation portion U from the transfer portion T as shown in FIG. 3B.
A strong air pressure is applied to the tapes 4, 5, and 6 over a wide area. That is, the pressure at the transfer portion T reaches a maximum (for example, 4 kg/cm ² ), and the pressure decreases as you move toward the tape running direction or the opposite tape running direction. For example, the rate of decrease in pressure in the area corresponding to the air trap groove 22 is 2.
Very low ~10%, 90-98% of maximum value
In other words, the pressure at the transfer section T of the tapes 4, 5, and 6 is almost the same as the pressure at the transfer section T.
It is possible to act on the transferred portion located between and the detachment portion U. Therefore, copy tape 4,
Even if the tension of the mother tape 5 changes, the relative positional relationship between the tapes 4 and 5 does not shift or becomes less likely to occur in the transferred portion. In this embodiment, the total pressing force of air against the tapes 4, 5, and 6 can be made to be about 7 to 8 kg, so that the tapes 4, 5, and
It was possible to completely eliminate any positional deviation in the relative positional relationship of No. 5. Therefore, according to this embodiment, the waveform of the signal transferred to the copy tape 4, which should originally have the form shown in FIG. The above-mentioned problem of the waveform as shown in FIG. 5B can be avoided.

By providing an air reservoir groove similar to the air reservoir groove 22 on the side opposite to the tape running direction from the air outlet 14 on the wall surface 2, the air pressure can be strongly applied to the area between the adhesion start part S and the transfer part T. You may also do this. In addition, since a deviation in the relative positional relationship between the copy tape 4 and the mother tape 5 in the untransferred area does not cause problems such as demagnetization, an air trap groove 22 is also provided on the opposite side of the tape running direction from the air outlet 14. Although it can be said that the necessity of providing it is not so great, it can be said that the overall pressing force of the air against the tapes 4, 5, and 6 can be increased, and it can be said that it has the advantage of more reliably preventing positional deviation.

In the embodiment described above, the present invention is applied to a type of transfer device that uses a drive tape 6 to run a copy tape 4 and a mother tape 5. The transfer device described in Japanese Patent No. 58-137137 is one example).

(H Effects of the Invention) As described above, the transfer device of the present invention has an air pocket that communicates with the air outlet in the opposite tape running direction from the air outlet on the wall surface facing the opposite tape running surface of the air guide. Since the groove is provided, the running tape can be strongly pressed against the tape guide member not only in the part corresponding to the air outlet but also in the part on the tape running direction side from there. Therefore, it is possible to prevent positional deviations from occurring between the tapes due to tension fluctuations or the like in the transferred portion of the running tape. Therefore, it is possible to prevent the level of the transfer signal from decreasing due to demagnetization of the magnetic signal due to positional deviation between the tapes.

[Brief explanation of the drawing]

1 and 2 show an example of the implementation of the transfer device of the present invention, in which FIG. 1 is a partially cutaway perspective view, FIG. 2 is a sectional view taken along the line - in FIG. 1, and FIG.
Figure 3 is a pressure distribution diagram showing the distribution of pressure due to air in the area where the tape guide member and tape are in close contact. Figure 4 is a cross-sectional plan view showing a type of transfer device that uses a drive tape to reduce tension fluctuations, and Figure 5 is a waveform diagram of the transfer signal. B shows a waveform when there is no demagnetization due to a shift in the relative positional relationship between the tapes, and B shows a waveform when there is demagnetization due to a shift in the relative positional relationship between the tapes. Explanation of symbols: 1... Tape guide member, 2... Air guide, 3... Wall surface, 4, 5... Traveling tape, 14...
Air outlet, 22...Air reservoir groove.

Claims (1)

[Scope of Claims] 1. A tape guide member that guides a running tape on a tape running surface, and a wall surface facing the tape running surface, and an air blower that blows air between the wall surface and the tape running surface. an air guide in which a blowout port is formed, and a transfer device that performs transfer while pressing the running tape running on the tape running surface against the tape guide member by the air blown out from the air blowout port, The wall surface is characterized by being provided with an air reservoir groove having a width narrower than the width of the running tape that communicates with the air guide and extends from there in the tape running direction by making a thin cut on the surface of the wall surface. Transfer device.