JPH0225161Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a device for detecting twisting of a tape, and in particular, to a device that reliably and easily detects twisting of a tape over the entire length of the tape. It is something. The term "tape" used here refers to a flexible strip-shaped recording material that is wound in a coil around a core or unwound from it, and broadly refers to magnetic tape, long photographic film, etc. It is.

(Prior art) In the manufacturing process, the tape wound around the annular core is generally 2 to 50 times the length of the product (hereinafter simply referred to as a "long hub"). The product is supplied to the user as a product that is wound around another annular core (hereinafter simply referred to as the "product hub") to a predetermined length and wound around another annular core (hereinafter simply referred to as the "product hub") suitable for the purpose of use. Note that the recording medium usually has a width of 3
~51mm long, 45~3000m long, and 3~50μm thick tape-like material containing polyethylene terephthalate, polyethylene-2,6-naphthalate, cellulose diacetate, cellulose striacetate, cellulose acetate butyrate, and cellulose acetate. Plastic film such as propionate, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyimide, polyamide, etc.; Paper; paper or polyethylene, polypropylene, ethylene-buden copolymer, etc. having 2 to 10 carbon atoms;
Recording and reproduction comprising a flexible support such as paper coated or laminated with α-polyolefins; metal foil of aluminum, copper, tin, etc.; magnetic film or photosensitive film, etc. layered on the surface of the flexible support. It is a medium for use. Typical products for this recording medium include audio tapes, video tapes, data tapes,
mm cine film, etc.

Generally, when rewinding the tape wound around the long hub onto the product hub, the long hub 2 around which the tape 1 is wound is fitted onto the unwinding shaft 3 as shown in FIG. , the tip of the tape 1 is engaged with the product hub 8 fitted to the winding shaft 7 via the guide roller groups 4 and 6 and the measuring roller 5, and then connected to the unwinding shaft 3 and the winding shaft 7. motor (not shown)
The tape is rotated to run the tape, the tape 1 is wound on the product hub 8, and the unwinding shaft 3 and the winding shaft 7 are stopped by a fixed length signal issued from the measuring roller 5, and then the tape is cut. operate the machine 9 to obtain a tape of a fixed length wound around the product hub 8;
Generally, a device called a winder is used.

However, in such cases there were the following drawbacks. In other words, because the thickness of the tape is thin and flexible (3 to 50 μm), and the width of the tape is narrow (3 to 51 mm), the tape may be twisted due to tension fluctuations or meandering while the tape is running, and the front and back sides of the tape may be twisted. In some cases, the front and back sides were wound the wrong way.

When the tape is wound upside down and used as a product, the recording head 10 has a base layer 1, as shown in FIG.
1 comes into contact and the magnetic layer 12 does not come into contact with each other, making it impossible to record, causing the inconvenience that it is impossible to record on videotape. Because it is difficult to determine whether the recording is being recorded or not, there have been cases where it has become clear that the recording was not recorded when playing back later, which caused a serious problem.

For this reason, with audio tapes, etc., there is a method of visually inspecting the front and back sides of the tape at the beginning and end of the winding, or as shown in Figure 3, the recording head 1
3. A method of disposing the reproducing head 14 and the erasing head 15 between the guide roller 4 and the measuring roller 5 to judge the input/output of electric signals, or using a projector (not shown) as shown in FIGS. 4A and 4B. ) is irradiated onto the tape surface through an optical fiber 16, and in the case of FIG.
There is a method of distinguishing between front and back by utilizing the phenomenon that light reaches the light receiver through the sensor, but in the case of Fig. 4B, the light does not reach the receiver, or as shown in Figs. A method has been used in which the difference in electrical resistance between the two electrodes is determined by multiplying by . However, in any of these methods, although it is possible to distinguish between front and back sides of a certain portion of the tape, it is impossible to reliably distinguish the entire length of the tape.

In other words, with the visual inspection method, it cannot be determined if the tape winding speed is high, and with the method using the recording/playback/erasing head, the tape has scratches caused by friction with the head, and if the running speed is high, the electrical signal cannot be detected. In addition to scratches caused by friction between the tape and the head, the optical fiber method also has the disadvantage that the optical fiber method can easily cause erroneous judgments due to unstable input/output or the tape floating from the head. If it floats, it will cause false judgments, and in the electrical resistance method, in addition to scratches that occur between the electrode and tape, when the tape is run, the contact force between the electrode and tape becomes uneven, causing false judgments. It was hot.

For this reason, a method has generally been adopted in which the beginning, end, or both ends of the tape are inspected with the naked eye, an optical fiber method, an electrical resistance method, or the like when the tape is not running.

(Problem that the invention aims to solve) However, in any of these methods, it is impossible to distinguish between the front and back sides of the central part of the wound product tape.
If the tape is reversed once during the run and then returned again, or if the long tape sent from the previous process is reversed midway through, the wrong side of the tape may end up being wrapped around the product hub. Ta. Furthermore, in products such as audio and video tapes where the tape thickness is thin, it has been impossible to detect the folded portion of the tape even if the wound end face is inspected in detail with the naked eye.

The present invention solves these conventional drawbacks and creates a simple and compact tape that can detect the flip of the tape in order to reliably distinguish the front and back sides of the tape over its entire length. The object of the present invention is to provide a twist detection device.

(Means for Solving the Problems) The tape twist detection device of the present invention includes a projector that irradiates light onto the tape, which is provided at a position facing the tape in the middle of the running tape, and which emits light onto the tape. It is characterized by comprising a light receiver that receives the light emitted from the light projector through the tape and detects a change in the length of the tape in the width direction due to twisting of the tape.

(Example) The contents of the present invention will be explained in more detail below based on the attached drawings from FIG. 6 onwards, which show one embodiment of the present invention.

In FIG. 6, ``A'' indicates a detecting section using the optical fiber method or the electrical resistance method, and ``B'' indicates a projected dimension change detecting section of the tape width. The tape width projected dimension change detecting section (B) will be explained in more detail with reference to FIGS. 7A, 7B and 8.

Figure 7A shows a state where the tape is running normally.
FIG. 7B shows a state in which a portion of the tape whose front and back sides have been changed is running between the guide roller 4 and the measuring roller 5. Ends 20 and 21 in the tape width direction between the guide roller 4 and the measuring roller 5
2 as shown in Figure 8 so that the optical axis passes through the position.
A pair of light emitters 22, 23 and light receivers 24, 25 are arranged with a tape sandwiched therebetween. In the state shown in FIG. 7A when the tape 1 is running normally, the projector 2
The light from the emitters 22 and 23 is blocked by the tape 1 and does not reach the receivers 24 and 25, but in the state shown in FIG. Since the light reaches the light receiver 24 or 25 or both without being obstructed by the tape, it is possible to detect the twist of the tape, thereby easily detecting the reversal of the front and back sides of the tape.

For example, a light emitting diode can be used as a light emitter and a phototransistor can be used as a light receiver, but a tungsten lamp, a solar cell, etc. may also be used as the light emitter and receiver. Alternatively, instead of using two pairs of light emitters and receivers, as shown in FIG. 9, the light from the lamp 26 is made into parallel light by a lens 27,
A method may be used in which the shadows of the magnetic tapes 11 and 12 are received by the linear array 28 and the tape twisting portion is detected based on changes in the amount of light from the linear array 28. This linear array 28 is formed by arranging a large number of photoelectric elements in the width direction of the tape, and determines the amount of light emitted from the lamp and received without being blocked by the tape, or the light receiving position. Therefore, it is a detection device that can detect twisting of the tape.

According to the present invention, a device that detects the twist in the middle part of the tape wound around the product hub must be installed in each winder, but a device that detects the beginning or end of the tape is required to If there is a place where all the tapes are collected in one place, grounding one unit there has the advantage of being cheaper and easier to maintain. Further, the device for detecting the end of the tape may be omitted.

The present invention can be applied to magnetic tapes, movies, etc.
It is also possible to apply the present invention to the detection of twist in the part where a slit web such as photographic film is wound.

(Effect of the invention) As explained above, according to the apparatus of the invention, the light emitted from the projector at the middle part of the running tape is received by the light receiver through the tape, and the light is received by the receiver in the longitudinal direction of the tape. Since changes are detected, twisting of the tape can be detected. Furthermore, by combining this device with a conventional device that detects only the front and back sides of the tape starting and ending ends, it becomes possible to reliably distinguish between the front and back sides of the tape over its entire length.

[Brief explanation of drawings]

Figure 1 is a front view of the winder, Figure 2 is an explanatory diagram showing how to use magnetic tape, Figures 3, 4A, 4B
Figures 5A and 5B are explanatory diagrams showing a conventional tape front and back discrimination device, Figure 6 is a front view showing an embodiment of the present invention, and Figures 7A, 7B, and 8 show details of Figure 6. FIG. 9 is an explanatory diagram showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Tape, 2... Long hub, 4, 6... Guide roller, 5... Measurement roller, 8... Product hub, 11... Base layer, 12... Magnetic layer, 18,
19... Electrode, 22, 23... Light emitter, 24, 2
5... Light receiver.

Claims (1)

[Scope of utility model registration request] A light projector that irradiates light onto the tape is provided at a position facing the tape in the middle of the running tape, and the light emitted from the light projector is received through the tape and A tape twist detection device comprising: a light receiver for detecting a change in length of the tape in the width direction due to twisting.