JPH04170741A - Tape rolling-up device - Google Patents

Abstract

PURPOSE:To always perform a high-speed tape rolling-up operation without being influenced by the state of a tape by a method wherein the end of the tape is judged by the number of revolutions of a tape reel and by the relative speed of the tape. CONSTITUTION:The speed at which a tape 5 is passed through a capstan 2 and the speed at which a reel 3 sends out the tape 5 are the same because they come into contact with the same tape. The speed at which the reel 3 sends out the tape can be obtained when the circumference of a rolled tape is multiplied by the turning speed of a tape reel. The radius of the left reel 3 is designated as LRr, its number of revolutions is designated as LRp, the radius of the capstan 2 is designated as CRr and its number of revolutions is designated as CRp. Since the rolling-up finish of the tape is considered as a state that the thickness of the tape is zero, and LRr and CRr are fixed by a tape rolling-up device, LRr : CRr = LRp : CRp is judged and the end of the tape can be judged.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tape winding device for magnetic tape used in audio and VTR.

[Conventional technology]

FIG. 2 is a block diagram of a conventional tape winding device. In the figure, 3.4 is a reel required for winding each tape, and the tape 5 is moved by being wound on this reel.

In FIG. 2A, the tape reel 3 is wound with a small amount of tape, and the tape reel 4 is wound with a large amount of tape.

In the opening of Figure 2, it is the opposite of A, with more tape being wound on the tape reel 3 and less tape being wound on the tape reel 4.

Each reel 3.4 is provided with a rotation number counter 6.7 for obtaining the number of rotations of the tape reel.

In order to wind the tape at a high speed in such a device, instead of winding the tape at a high speed, it is necessary to determine the end of the tape, then slow down the tape winding speed at the end of the tape, and end the tape in a low continuous state. There is a need to. If you wind up the tape without doing this, you will not only damage the tape at the end of winding it, but you may even break the tape. For this reason, the following method has conventionally been used.

The two states shown in FIG. 2 will be explained.

The number of rotations can be obtained from each tape reel 3.4. In order to know to what position the tape has been wound, it can be determined by the rotation speed ratio of each tape.

This takes advantage of the fact that the number of revolutions varies depending on the state of tape winding; when more tape is wound up, the number of revolutions decreases, and conversely, when less tape is wound up, the number of revolutions increases.

To use this to wind the tape at high speed from the state in Figure A to the state in Figure A, take the ratio of tape reels 3 and 4 at the number of rotations of the tape in Figure A, and make the ratios opposite. Assume that there is a tape up to 100, and wind the tape at high speed until the opposite ratio is reached. This realizes high-speed winding of the tape.

[Problem R that the invention attempts to solve]

Since the conventional tape winding device utilizes the ratio of the rotational speed of the tape reel 3.4 shown in FIG. 2, the larger this ratio is, the longer the section in which the tape is wound at high speed, and a greater effect can be obtained. However, when the above ratio is the minimum (1:1), there is no difference from the current situation even if the ratio is reversed, and high-speed winding cannot be performed.

This invention was made to solve the above problems, and the object is to obtain a tape winding device that can always wind up a tape at high speed regardless of the state of the tape. Means for Solving the Problems] A high-speed tape winding device according to the present invention is configured to determine the end of the tape based on the number of rotations of the tape reel and the relative speed of the tape.

[Effect]

The effect of obtaining the relative speed of the tape is that it becomes possible to determine when the tape has ended, making it possible to wind the tape at high speed without being affected by the state of the tape. This takes advantage of the fact that the relative speed of the tape and the speed of the tape fed by the tape reel are the same.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. As in the prior art, the tape 5 is wound on a 3.4 tape reel in FIG. 1, and the number of rotations of the tape reel is determined by this. Tape 5 goes to control
and is in contact with capstan 2. 8 is a capstan rotation number counter. A feature of the present invention is that the relative speed of the tape is determined by the number of revolutions of the capstan.

Next, the operation will be explained with reference to FIG. The speed at which the tape 5 passes through the capstan 2 and the speed at which the reel 3 feeds out the tape 5 are equivalent because they are in contact with the same tape. Further, the speed at which the reel 3 feeds out the tape is obtained by multiplying the circumference of the wound tape by the rotational speed of the tape reel. Therefore, the tape speed can be obtained from the following equation.

Formula: Circumference of capstan x Number of revolutions of capstan 2 Circumference of wound tape Assuming the % rotation speed as ORF, find the formula for determining when the tape winding is complete. With this configuration, the number of rotations of the reel and the radius of the reel body can be obtained, but there is no way to directly obtain the radius including the tape wound around the reel.

First, it is assumed that the tape thickness is O at the end of tape winding, so the speed of the tape in contact with the left reel 3 is determined by (2πLRrXLR1)), and the speed of the tape in contact with the capstan is (2πLRrXLR1)). 2rour X 0
RE)). Furthermore, since the speeds of these tapes are the same, they can be calculated using the following formula.

Formula: % formula % However, the radius of one left reel 3 (Left-R・el-radiu
s) == LRr・Rotation speed of left reel 3 (Left-
Reel-pu1m@) -LRp Capstan 2
Radius of (C!apstan-Bs*l-r&diu-R-ORr-Number of times'@(Oap*tt
n-Roe knee pulse) -, ORp.

Of these, the radius of LRr and ORr is fixed by a tape winding device. Therefore, it is sufficient to judge the following formula.

Formula: % Formula %: In the above embodiment, the relative speed of the tape was obtained from the rotational speed of the capstan, but it is also possible to obtain the relative speed from information such as the control head.

Furthermore, in the above embodiment, the explanation was given to determine the end of the tape, but by using the relative speed t of the present invention, it is also possible to calculate the remaining amount of the tape operating at a constant speed. be.

For example, if the current rotation speed of the left reel is f LRpl,
Let the rotation speed after 1 second of operation be T seconds be LRI)2, and the rotation speed of the left reel at the end be LRpO.

Tape reel speed is T seconds from LRpl to LRI)
The time required for the tape to run until it becomes empty with this amount of change, which changes to 2, is determined by the following equation.

Formula: % Formula %) [Effects of the Invention] As described above, according to the present invention, it becomes possible to wind up the tape at high speed without affecting the amount of tape winding.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a high-speed winding of a tape according to an embodiment of the present invention, and FIG. 2A is a block diagram of a conventional high-speed tape winding. In the figure, 1 is the control head, 2 is the capstan, and 3
is the left reel, 4 is the right reel, 5 is the tape, and 6.7.8 is the rotation number counter. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] In a tape winding device that has the function of determining the rotational speed of the reel that winds the tape and the function of determining the relative speed of the tape, the end of the tape is determined based on the rotational speed of the tape reel and the relative speed of the tape. Features a tape winding device.