JPH08337354A - End sensing device for belt-shaped transparent sheet - Google Patents

Abstract

PURPOSE: To sense certainly the end of a belt-shaped transparent sheet under conveyance. CONSTITUTION: A laser projecting part 11 is installed so that the side edge of a belt-shaped transparent sheet S to be conveyed is irradiated, and a laser beam reception part 12 is installed to receive the beam from the laser projecting part 11, and a polarizing filter 13 is installed between the part 11 and sheet S so that the beam from the part 11 is allowed to pass through. Because the phase of the beam having penetrated only the filter 13 is largely different from the phase of the beam having penetrated both the filter 13 and sheet S, it can serve for sensing of the end part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting the edge of a belt-shaped transparent sheet being conveyed.

[0002]

2. Description of the Related Art Conventionally, a sensor using a laser beam has been generally used for measuring the position and size of an object to be measured with an accuracy of a micron unit. Among them, the transmissive sensor detects the interruption of the laser light due to the opaque body, but recently, the transmissive sensor that has realized the detection of the transparent body by improving the accuracy and stabilization of the processing circuit has been developed. There is.

[0003]

However, when detecting the edge of a thin transparent film such as that used in the base film of a magnetic tape, the light transmittance of this transparent film is very close to that of air. However, there is a problem in that detection is difficult even with the above-mentioned transmission type sensor. On the other hand, although it is possible to detect the edge by using the reflection on the film surface, if the transparent film that is the object to be measured is in the transportation state, the accuracy of the measurement deteriorates due to the influence of flapping during transportation. There is a problem.

The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to reliably detect the end of a thin transparent transparent sheet which is being conveyed. It is to provide a detection device.

[0005]

In order to achieve the above object, an edge detecting device according to the present invention is a laser projecting section arranged so as to irradiate the vicinity of a side edge of a belt-shaped transparent sheet being conveyed. And a laser light receiving portion arranged to receive the light from the laser light emitting portion, and a laser light receiving portion disposed between the laser light emitting portion and the band-shaped transparent sheet so as to transmit the light from the laser light emitting portion. And a polarizing filter provided.

[0006]

In the edge detecting device of the present invention having the above-mentioned structure, the light from the laser projecting portion once passes through the polarizing filter, and this transmitted light irradiates the vicinity of the side edge of the band-shaped transparent sheet. Since the phase of the light that has passed through only the polarizing filter and the phase of the light that has passed through both the polarizing filter and the transparent sheet are significantly different, the edge of the band-shaped transparent sheet can be easily detected.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of a magnetic tape slitter equipped with an edge detecting device according to the present invention, and FIG. 2 is a plan view of FIG.

The slitter shown in the figure cuts a raw sheet S having a magnetic material powder M applied to one side of a base film F into a predetermined width, and its basic structure is the same as that of a conventional one. . The original sheet S is of a wide width in which the applied portions B are formed on substantially the entire surface except the uncoated portions A on both side ends thereof. As shown in the figure, the slitter winds the original sheet S of the magnetic tape (Fig. (Not shown), is passed through the guide rollers 1 and 2, and is cut into a predetermined width by a knife portion composed of the bladed roller 3 and the receiving roller 4, and then the cut product portion and the ear portion are taken up by a winding device (not shown). It is supposed to be rolled up individually. During this cutting, if the original sheet S is misaligned especially at the knife portion, quality deterioration such as width variation and meandering curve occurs. Therefore, in order to prevent these quality deteriorations, in the slitter of this embodiment, before the original sheet S enters the first guide roller 1,
As shown in the figure, the edge detecting device 10 is installed to monitor the transport state immediately before cutting.

As shown in the enlarged view of FIG. 3, the edge detecting device 10 includes a laser projecting section 11 arranged so as to irradiate the vicinity of the side edge of the original sheet S being conveyed, and the laser projecting section 11. A laser light receiving portion 12 arranged to receive the light from the light portion 11, and a laser light receiving portion 12 arranged between the laser light emitting portion 11 and the original sheet S so as to transmit the light from the laser light emitting portion 11. The polarizing filter 13 is provided, and the end portion of the original sheet S is detected by irradiating the vicinity of the side edge of the original sheet S with the light transmitted through the polarizing filter 13. It should be noted that the laser projecting unit 11 is provided with light emitting elements in one row, and the laser light receiving unit 12 is provided with light receiving elements in one row corresponding to the light emitting elements. Also,
In this embodiment, the light receiving mask 14 is arranged between the original sheet S and the laser light receiving portion 12 so as to block a part of the uncoated portion A from the coating portion B side, and the detection amount in the laser light receiving portion 12 is increased. Is to be the minimum necessary. Further, as shown in FIG. 4, the edge detecting device 10 includes a laser sensor amplifier 21, a pen recorder 2, and a laser light receiving portion 12 thereof.
2. The FFT analyzer 23 is connected.

A normal laser sensor is a sensor that utilizes the fact that the light emitted from the laser projecting section reaches the laser receiving section by the object to be measured. Detection is performed by temporarily transmitting the light emitted from the laser projecting unit 11 through the polarization filter 13 and further transmitting this transmitted light only through the portion of the base film F which is the object to be measured. That is, since the phase of the light transmitted only through the polarization filter 13 and the phase of the light transmitted through both the polarization filter 13 and the base film F are significantly different, the latter light becomes brighter than the former light, and the laser light receiving unit 12 This is because it is compatible with the processing characteristics of the light receiving element and the laser sensor amplifier 21. Specifically, the detection amount of the base film F portion obtained by the light receiving element of the laser light receiving unit 12 is converted into a voltage signal by the laser sensor amplifier 21 and recorded by the pen recorder 22, and at the same time, the original sheet S meanders. The FFT analyzer 23 can be loaded so that correlation data with vibration analysis can be obtained. As a result, it is possible to measure the meandering during cutting, and it becomes possible to perform more advanced edge control by feeding back the measurement results.

Further, by combining the above-mentioned edge detecting device 10 with an alarm device, the change in tension of the original sheet S increases, the rotation failure of the guide rollers 1 and 2 occurs, and the electric control system malfunctions. It is possible to detect the deterioration of the mechanical state, the shape of the original sheet S, the winding deformation, the winding mounting failure, etc. at an early stage, and it is possible to improve the product yield.

[0013]

As described above, according to the edge detecting device of the present invention, it is possible to reliably detect the edge of the belt-shaped transparent sheet which is in the transporting state, only by providing the conventional laser sensor with the polarization filter. You can

[Brief description of drawings]

FIG. 1 is a side view of a magnetic tape slitter provided with an edge detecting device according to the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is an enlarged explanatory view of an edge detection device.

FIG. 4 is an overall configuration diagram of an edge detection device.

[Explanation of symbols]

 10 Edge Detection Device 11 Laser Projector 12 Laser Receiver 13 Polarization Filter

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location G01V 8/10 9406-2G G01V 9/04 R G11B 5/00 9406-2G U

Claims (1)

[Claims] 1. A laser projecting section arranged to irradiate the vicinity of a side edge of a belt-shaped transparent sheet to be conveyed, and a laser receiving section arranged to receive light from the laser projecting section. And a polarizing filter disposed between the laser projection unit and the band-shaped transparent sheet so as to transmit the light from the laser projection unit, and an edge detection device for the band-shaped transparent sheet. .