Inspection unit for web-conveyed object

Abstract

The present invention provides an inspection unit for a web-conveyed object, in which the web length of an inspection zone is reduced. In this inspection unit for a web-conveyed object, an interval L between a front-side floating conveyance device 1 and a rear-side floating conveyance device 2 arranged before and after an inspection device B is equal to or less than the total length (R1 + R2) of the radius R1 of the front-side floating conveyance device 1 and the radius R2 of the rear-side floating conveyance device 2.

Description

Inspection unit for web transported items

[0001] The present invention relates to an inspection unit for a web-carried object.

[0002] Web transport refers to the technology of transporting and storing thin sheet-like products (webs) wound into rolls, such as film or foil. Web-transported objects are a general term for objects transported by web transport. Inspection of such web-transported objects typically involves capturing images using both a transmitted light source and a reflected light source and then performing image processing. Inspection using a transmitted light source requires a light source to be installed on the backside of the web-transported object (see, for example, Patent Document 1). Conventionally, light sources have been installed between two transport rollers. However, while the light source itself can be narrowed using optical fibers or light guides, installing it between two transport rollers results in a long web length in the inspection section, which can lead to defects such as wrinkles when the web passes through the inspection device. Furthermore, using two transport rollers also creates dead space, requiring a large installation space for the inspection device.

[0003] JP 2013-253906 A

[0004] An object of the present invention is to provide an inspection unit for a web-transported object in which the web length in the inspection section is shortened.

[0005] According to one aspect of the present invention, there is provided an inspection unit for a web-transported object, in which a distance L between a front floating transport device and a rear floating transport device disposed before and after the inspection device is equal to or less than the sum of a radius R1 of the front floating transport device and a radius R2 of the rear floating transport device (R1 + R2).

[0006] According to the present invention, since the distance L between the front floating conveying device and the rear floating conveying device arranged respectively before and after the inspection device is less than the total length (R1 + R2) of the radius R1 of the front floating conveying device and the radius R2 of the rear floating conveying device, an inspection unit for web-transported objects can be provided in which the web length of the inspection section is shortened.

[0007] 1 is a cross-sectional view conceptually showing the configuration of an inspection unit for a web-transported object according to one embodiment of the present invention; 2 is a cross-sectional view conceptually showing the configuration of an inspection unit for a web-transported object according to another embodiment of the present invention; 3 is a cross-sectional view conceptually showing the configuration of a front-side floating transport device and a rear-side floating transport device; 4 is a cross-sectional view conceptually showing the configuration of a modification of the front-side floating transport device and the rear-side floating transport device; 5 is a cross-sectional view conceptually showing the configuration of an inspection unit for a web-transported object according to prior art;

[0008] FIG. 1 conceptually illustrates, in cross section, the configuration of a web-transported object inspection unit (hereinafter simply referred to as "inspection unit") according to one embodiment of the present invention. The inspection unit A1 shown in the figure includes a front-side floating transport device 1 and a rear-side floating transport device 2, which are disposed before and after an inspection device B, respectively. The distance L between the front-side floating transport device 1 and the rear-side floating transport device 2 is equal to or less than the sum of the radius R1 of the front-side floating transport device 1 and the radius R2 of the rear-side floating transport device 2 (R1 + R2). Here, the distance L between the front-side floating transport device 1 and the rear-side floating transport device 2 refers to the distance along the transport direction of the web-transported object W, and this distance L corresponds to the "web length of the inspection section."

[0009] 1, inspection device B is a transmission-type inspection device including a transmission light source B1 and a camera B2, with transmission light source B1 being arranged on the back side of the web transported object W. Note that in the present invention, the inspection device is not limited to the transmission-type as shown in FIG. 1, but may be a reflection-type inspection device including a reflection light source and a camera, or may be a combination of a transmission type and a reflection type, or may be a semi-transmission type. In any case, in the present invention, a front-side floating transport device and a rear-side floating transport device are arranged before and after the inspection device, respectively.

[0010] 1, the front-side floating conveying device 1 and the rear-side floating conveying device 2 have quarter-arc floating conveying surfaces 11 and 21, respectively. These floating conveying surfaces 11 and 21 can be formed, for example, from a porous material, and in this case, the web-shaped transport object W is floated and conveyed by ejecting gas from the floating conveying surfaces 11 and 21. However, in the present invention, the system of the front-side floating conveying device and the rear-side floating conveying device is not limited to the above-mentioned gas ejection system, and known systems such as systems using ultrasonic waves or magnetism can also be used.

[0011] 1 , the distance L between the front-side floating transport device 1 and the rear-side floating transport device 2, which are respectively disposed before and after the inspection device B, i.e., the web length of the inspection section, is less than or equal to the sum of the radius R1 of the front-side floating transport device 1 and the radius R2 of the rear-side floating transport device 2 (R1 + R2). On the other hand, as shown in FIG. 5 , in a conventional inspection unit in which the front-side transport rollers 5 and the rear-side transport rollers 6 are respectively disposed before and after the inspection device B, the distance L between the front-side transport rollers 5 and the rear-side transport rollers 6, i.e., the web length of the inspection section, necessarily exceeds the sum of the radius R1 of the front-side floating transport device and the radius R2 of the rear-side floating transport device (R1 + R2). Thus, according to the present invention, an inspection unit for a web-transported object can be provided in which the web length of the inspection section is shortened.

[0012] Figure 2 conceptually illustrates, in cross section, the configuration of an inspection unit for a web-transported object according to another embodiment of the present invention. The inspection unit A2 shown in this figure is identical to the inspection unit A1 of Figure 1 except for the arrangement of the rear floating transport device 2. That is, in the inspection unit A2 of Figure 2, the distance L between the front floating transport device 1 and the rear floating transport device 2, which are respectively arranged before and after the inspection device B, i.e., the web length of the inspection zone, is also less than the sum (R1 + R2) of the radius R1 of the front floating transport device 1 and the radius R2 of the rear floating transport device 2. Therefore, the embodiment of Figure 2 also provides an inspection unit for a web-transported object with a shortened web length of the inspection zone.

[0013] 3 shows a specific configuration example of the front-side floating transport device 1 and the rear-side floating transport device 2. In FIG. 3, the front-side floating transport device 1 and the rear-side floating transport device 2 are arranged in parallel on a substrate 3 and integrated, and a groove portion 4 having a distance L therebetween is formed between the front-side floating transport device 1 and the rear-side floating transport device 2. Although not shown in FIG. 3, for example, a transmitted light source B1 of the inspection device B shown in FIGS. 1 and 2 is disposed in the groove portion 4. Furthermore, like the distance L shown in FIGS. 1 and 2, the distance L shown in FIG. 3 is equal to or less than the total length (R1 + R2) of the radius R1 of the front-side floating transport device 1 and the radius R2 of the rear-side floating transport device 2, and corresponds to the web length of the inspection section.

[0014] In Fig. 3, the front-side floating conveying device 1 and the rear-side floating conveying device 2 have floating conveying surfaces 11 and 21, respectively, in the same manner as in Figs. 1 and 2. In Fig. 3, these floating conveying surfaces 11 and 21 are formed by placing a porous body on the surface of the respective base materials 12 and 22. That is, in Fig. 3, the web-transported object W is floated and conveyed by ejecting gas from the floating conveying surfaces 11 and 21 made of a porous body. Note that the gas supply path to the floating conveying surfaces 11 and 21 made of a porous body is omitted from Fig. 3.

[0015] In this way, by integrating the front-side floating transport device 1 and the rear-side floating transport device 2, it is possible to easily set and adjust the distance L. Note that in Fig. 3, the front-side floating transport device 1 and the rear-side floating transport device 2 are integrated using a substrate 3, but the configuration for integration is not limited to this, and for example, the front-side floating transport device 1 and the rear-side floating transport device 2 can also be integrated using a side plate as in Fig. 2. However, when the front-side floating transport device 1 and the rear-side floating transport device 2 are arranged in parallel as in Fig. 1, it is preferable to integrate them using a substrate 3 as in Fig. 3 from the viewpoint of simplifying the device configuration, etc.

[0016] 1 to 3, the floating conveying surfaces 11 and 21 are quarter-arc shaped, but the shapes of the floating conveying surfaces 11 and 21 are not limited to quarter-arc shapes and can be made smaller or larger than a quarter-arc. However, from the viewpoint of reducing the interval L, it is preferable that the shapes of the floating conveying surfaces 11 and 21 be semi-arc or smaller, and further from the viewpoint of simplifying the device configuration, it is more preferable that they be quarter-arc.

[0017] 1 to 3, the floating conveying surfaces 11 and 21 are almost exact partial arcs. Therefore, the radius R1 of the front floating conveying device 1 and the radius R2 of the rear floating conveying device 2 are constant over the entire length of the floating conveying surfaces 11 and 21. However, in the present invention, the floating conveying surfaces 11 and 21 do not need to be exact partial arcs, and may be parabolic, for example, as shown in FIG. 4. In this case, the radii of the front floating conveying device 1 and the rear floating conveying device 2 vary depending on the positions of the floating conveying surfaces 11 and 21. In this invention, the radius R1 of the front floating conveying device 1 is defined as the radius of the floating conveying surface 11 at the position where the web conveyed object W separates, i.e., the rearmost end 111 of the floating conveying surface 11, between this starting point 111, a point 112 10 mm long from the starting point 111 along the floating conveying surface 11, and a point 112 10 mm long from the starting point 111 along the floating conveying surface 11. The radius R2 of the rear floating transport device 2 refers to the radius of an arc that passes through three points: the point 111, a point 212 that is 10 mm from the starting point 211 along the floating transport surface 21, and a point 213 that is 20 mm from the starting point 211 along the floating transport surface 21 (see FIG. 4). Note that in FIG. 4, the positions of the three points (111, 112, 113) and (211, 212, 213) do not necessarily accurately reflect the actual dimensions, but are merely shown conceptually.

[0018] A1, A2 Inspection unit for web transported object B Inspection device B1 Transmitted light source B2 Camera W Web transported object 1 Front floating transport device 11 Floating transport surface 111 Rearmost end (starting point) of floating transport surface 112 Point 10 mm long from the starting point along the floating transport surface 113 Point 20 mm long from the starting point along the floating transport surface 12 Substrate 2 Rear floating transport device 21 Floating transport surface 211 Frontmost end (starting point) of floating transport surface 212 Point 10 mm long from the starting point along the floating transport surface 213 Point 20 mm long from the starting point along the floating transport surface 22 Substrate 3 Substrate 4 Concave groove portion 5 Front transport roller 6 Rear transport roller

Claims

1. An inspection unit for a web-transported object, in which the distance L between a front side floating conveying device and a rear side floating conveying device arranged respectively before and after the inspection device is less than the total length (R1 + R2) of the radius R1 of the front side floating conveying device and the radius R2 of the rear side floating conveying device.

2. An inspection unit for a web-transported object as described in claim 1, wherein said front side floating transport device and said rear side floating transport device each have a floating transport surface shaped like a quadrant arc.

3. An inspection unit for a web transported object as described in claim 1 or 2, wherein the front side floating transport device and the rear side floating transport device are integrated together.

4. An inspection unit for a web-transported object as described in claim 1 or 2, wherein the front-side floating transport device and the rear-side floating transport device are arranged in parallel on a substrate and integrated, and a groove portion having the distance L is formed between the front-side floating transport device and the rear-side floating transport device.

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