JPH02107902A - Web position detector - Google Patents

Abstract

PURPOSE:To enable a highly accurate detection of a position by arranging a projector, a slide contact body for keeping a distance between the projector and a web constant and a light receiving means to suppress the generation of errors in the detection of the position of the web due to a bending and vibration of the web. CONSTITUTION:An inspecting beam of light 16 out of those 16 radiated from a projector 11 passing outside an edge part 14a of a web 14 is incident into light receivers 17 and 18. The light receivers 17 and 18 are provided with a lens for condensing the inspecting beam 16 and photomultiplier tubes (PMT) 19 and 21 are arranged. The PMTs 19 and 21 amplify the inspecting beam 16 incident to be converted to electricity. The resulting photoelectric signal is supplied to a positional deviation detector 22, with which the photoelectric signal is monitored and based on a change in the photoelectric signal, the detector reports the occurrence of a positional deviation across the width thereof and the degree thereof is reported. This enables detection of a width-wise positional deviation of the web at at high accuracy, thereby ultimately realizing a highly accurate surface inspection.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a web position detection device, and more particularly to a position detection device for detecting a positional shift in the width direction of a web.

[Conventional technology]

In FIG. 5 showing a conventional web position detection device,
The web 52 is transported in the X direction indicated by the arrow through the bus rolls 50 and 51. The projector 53 emits inspection light from below the web 52, and the receivers 54 and 56 receive this inspection light. At this time, the inspection light directed toward the lower surface of the web 52 is reflected and absorbed by the web 52, and the light is transmitted to the light receiver 54.
．． It never reaches 56. Therefore, the web 52
Only the inspection light passing outside the edge portion 52a of the light beam enters the light receiver 54.56. Photoreceivers 54 and 56 perform photoelectric conversion, and each outputs a photoelectric signal corresponding to the amount of incident light.

The positional deviation detector 57 that monitors the fluctuation of this photoelectric signal is
It is detected that a positional shift has occurred in the width direction of the web 52. By also detecting the amount of variation in the inspection light received at this time, the degree of positional deviation can be known at the same time (Japanese Utility Model Publication No. 52130/875).

Note that the same effect can be achieved even when the light receivers 54 and 56 described above are disposed below the web 52 and the light projector 53 is disposed above.

[Problem to be solved by the invention]

However, in the positional deviation detection method as described above, even if the web 52 vibrates between the light emitter 53 and the light receivers 54, 56 or the edge portion 52a bends, the light receiver 5
Since the amount of light incident on 4.56 fluctuates, it cannot be distinguished from the case where a positional shift occurs. Moreover, this vibration and bending reduce the reliability of the detection result regarding the degree of positional deviation.

[Purpose of the invention]

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to provide a web position detection device that does not cause web vibration or edge bending.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a light projector that projects an inspection light, a sliding member that transmits the test light and slides into contact with the nib to ensure a constant distance between the projector and the web; A web position detection device is constituted by a light receiving means that receives the inspection light and detects the position of the web in the width direction.

Further, a light source means for projecting inspection light onto the web to be transported, and a transparent roll containing the light source means and slidingly contacting the nib may be provided.

Furthermore, it may be simple to provide a projector that allows the web to slide directly onto the surface of the projector.

[Effect]

Since the positional shift of the web being transported while sliding on the circumferential surface of the sliding body is detected, vibration or bending of the web cannot occur when the inspection light is being projected from the projector. Therefore, it is possible to detect the positional shift in the width direction of the web with high precision, thereby making it possible to realize surface inspection with even higher precision.

In addition, when a transparent roll is used, the web position can be detected by receiving inspection light projected onto the web slidingly in contact with the transparent roll.

Furthermore, when the web is directly brought into sliding contact with the surface of the projector, the same effect can be achieved while simplifying the structure.

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

〔Example〕

In FIG. 1, which schematically shows a web position detection device according to the present invention, a pass roll 10 made of a material that transmits light has a built-in light projector 11 and is rotatably arranged. The projector 11 is arranged so that its longitudinal direction coincides with the rotation axis of the pass roll 10. Support protrusions 10a are provided at both ends of the pass roll 10 to rotatably support the pass roll 10.
is provided. The projector 11 receives power from a power source 13 via a slip ring 12 provided at the tip of the support protrusion 10a. Geeb 14 is being transported in the longitudinal direction indicated by the arrow. Of the inspection light 16 emitted from the projector 11, the inspection light 16 that has passed outside the edge portion 14a of the web 14 enters the light receiver 17.18.

The light receivers 17 and 18 are equipped with lenses for condensing the inspection light 16, and each has a photomultiplier tube (P, M T ).
, , 19 and 21 are installed. Photomultiplier tube 1
At 9 and 21, the incident inspection light 16 is amplified and photoelectrically converted. The same applies to a light receiver in which a plurality of light receiving elements are arranged in place of a photomultiplier tube. This photoelectric signal is supplied to the positional deviation detector 22. The positional deviation detector 22 monitors the photoelectric signal, and based on this fluctuation, notifies that a positional deviation has occurred in the width direction and the degree of positional deviation.

In FIG. 2 showing another embodiment of the present invention, (A) is a front view, showing that the web 14 is transferred in direct sliding contact with the projector 30. This is a side view (a)
As shown in FIG.
is arranged at a higher position than both pass rolls 31' and '32.

This embodiment has the advantage that the conventional web position detection device can be used as is. At that time, it is necessary to pay attention to the smoothness of the peripheral surface of the projector 30 and the heat dissipation means.

In FIG. 3 showing another embodiment, a bath roll 36 made of a material that transmits light includes a light projector 37 and a power supply device 38 that supplies power to the light projector 37.

The power supply device 38 is fixed to the support member 40 inside the horizontal roll 36.

Further, reference numerals 40a and 40b indicate support members. Support member 4
The projectors 37 are arranged in alignment with the center of rotation of the bath roll 36 by 0a and 40b.

When the web 14 is transported, the bath roll 36 rotates together with them. In this embodiment, there is no need to use a slip ring, so the configuration can be simplified.

In FIG. 4 showing yet another embodiment, a bath roll 41 made of a material that transmits light is rotatably disposed. A floodlight 42 is provided below. Therefore, the distance d between the light projector 42 and the web 14 is maintained constant, the web 14 does not vibrate or bend, and the accuracy of detecting the positional deviation of the web 14 in the width direction can be improved. In the case of this embodiment, it is best to arrange the projector 42 on the opposite side of the position where the web 14 makes sliding contact with the bath roll 41.

〔Effect of the invention〕

As described above, the web position detection device of the present invention includes a light projector that projects inspection light onto the web, and a sliding body that transmits the test light and slides into contact with the web to ensure a constant distance between the projector and the web. and a light receiving means for receiving the inspection light and detecting the position of the web in the width direction. Therefore, errors in detecting the web position due to web vibration or bending can be suppressed, and highly accurate web position detection can be performed.

Furthermore, when a transparent roll that slides on the web is used, the web position can be easily detected. Furthermore, if the web is brought into direct sliding contact with the surface of the projector, it is possible to provide a very simple and highly accurate web position detection device.

4,

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of a web position detection device according to the present invention. FIG. 2 shows another embodiment according to the present invention,
(A) shows a front view, and (B) shows a side view. FIG. 3 is a front view showing an embodiment of the web position detection device according to the present invention. FIG. 4 is a front view showing an embodiment of the web position detection device according to the present invention. FIG. 5 is an explanatory diagram of the appearance of a conventional web position detection device. 19.21...Photomultiplier tube 22...Position shift detector. 10... Bath roll 11... Emitter 12... Slip ring 13... Power supply 14... Web 16... Inspection light 17.18... Light receiver

Claims (3)

[Claims] (1) A light projector that projects an inspection light onto the web being transported, a sliding body that transmits the test light and slides into contact with the web to ensure a constant distance between the projector and the web, and the test light 1. A web position detection device comprising: a light receiving means for receiving light and detecting a position in the width direction of the web. (2) A light source unit that projects an inspection light onto the web being transported, a transparent roll containing the light source unit and in sliding contact with the web, and detecting the position in the width direction of the web by receiving the inspection light. 1. A web position detection device comprising a light receiving means. (3) Projecting an inspection light onto the transported web,
A web position detection device comprising: a light projector that brings the web into direct sliding contact with the surface thereof; and a light receiving means that receives the inspection light and detects the position of the web in the width direction.