Sheet inspection device

Abstract

The present invention provides a sheet material inspection device capable of achieving space saving, reduction of component costs and reduction of maintenance man-hours. A first light source unit (Ls1) and a first inspection unit (S1) for inspecting defects on the front side of a sheet material and a second light source unit (Ls2) and a second inspection unit (S2) for inspecting defects on the back side of a sheet material are arranged in the following positional relationship: when there is a hole in the sheet material, the first inspection unit (S1) can detect light irradiated by the second light source unit and passing through the hole in the sheet material.

Description

Technical Field

[0001] The present invention relates to a sheet material inspection device. Background Art

[0002] In the past, as a sheet material inspection device for inspecting defects and holes on the front and back sides of a sheet material to be inspected, a structure has been proposed that includes two defect inspection units that inspect defects on the front and back sides of the material to be inspected, respectively, and a light-transmitting hole defect inspection unit that inspects hole defects in the material to be inspected (for example, refer to patent document 1).

[0003] However, when an optical inspection device is used as a flaw inspection device, it is necessary to provide a front light source and a back light source for irradiating the front and back sides of the inspected material, respectively, and a front detection unit and a back detection unit for detecting the reflected light from the inspected material of the light emitted from the front light source and the back light source, respectively. Therefore, as a sheet material inspection device, at least six elements need to be configured, including a transmission light source for detecting holes in the inspected material and a hole detection unit for detecting light emitted from the transmission light source and passing through the holes.

[0004] However, when such a sheet inspection device is assembled in a part of another device, a large space needs to be secured for the sheet inspection device, which hinders the miniaturization of the entire device. In addition, the sheet inspection device has many components, which increases the cost and the maintenance man-hours.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2001-343331 Summary of the invention

[0008] Problems to be solved by the invention

[0009] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a sheet inspection device capable of achieving space saving, reduction of component costs, and reduction of maintenance man-hours.

[0010] Means for solving problems

[0011] The present invention for solving the above-mentioned problems is a sheet material inspection device, which inspects defects of the inspected material, and is characterized in that it comprises: a first light source unit, which irradiates the first surface of the sheet-shaped inspected material; a first inspection unit, which detects reflected light of the light irradiated by the first light source unit and reflected by the first surface of the inspected material; a second light source unit, which irradiates the second surface of the inspected material; and a second inspection unit, which detects reflected light of the light irradiated by the second light source unit and reflected by the second surface of the inspected material, wherein the first inspection unit is arranged at the following position: at this position, when there is a hole in the inspected material, the first inspection unit can detect the light irradiated from the second light source unit and passed through the hole.

[0012] According to the present invention, the second light source unit that irradiates light to the back of the sheet material in order to inspect the defects on the second surface of the sheet material also functions as a light source for inspecting the holes of the sheet material, and the first inspection unit for inspecting the defects on the first surface of the sheet material also functions as a hole inspection unit for inspecting the holes of the sheet material. Therefore, a separate light source and inspection unit for inspecting the holes of the sheet material can be omitted. In this way, the number of components of the sheet material inspection device can be reduced, so that space saving and cost reduction can be achieved, and maintenance man-hours can be reduced.

[0013] In the present invention, the first inspection unit may detect regular reflection light of light irradiated by the first light source unit and reflected by the first surface, and the second inspection unit may detect regular reflection light of light irradiated by the second light source unit and reflected by the second surface.

[0014] This makes it possible to inspect the first surface and the second surface of the sheet for defects with high accuracy.

[0015] In addition, in the present invention, the incident angle of the light irradiated by the first light source unit and the reflection angle of the regular reflected light detected by the first inspection unit may both be 10±5 degrees, and the incident angle of the light irradiated by the second light source unit and the reflection angle of the regular reflected light detected by the second inspection unit may both be 10±5 degrees.

[0016] In this way, it is possible to reliably inspect whether a thin material to be inspected has pinholes.

[0017] Effects of the Invention

[0018] According to the present invention, it is possible to provide a sheet material inspection device capable of achieving space saving, reduction in component costs, and reduction in maintenance man-hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] [ Figure 1 ] is a diagram showing the main structure of the inspection device of an embodiment of the present invention.

[0020] [ Figure 2 ] is a functional block diagram of a sheet inspection device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] [Application Examples]

[0022] Hereinafter, application examples of the present invention will be described with reference to the drawings.

[0023] In the present invention, if Figure 1 As shown, the first light source unit Ls1 and the first inspection unit S1 for inspecting defects on the front side of the sheet and the second light source unit Ls2 and the second inspection unit S2 for inspecting defects on the back side of the sheet are arranged in the following positional relationship: when there is a hole on the sheet, the first inspection unit S1 can detect light irradiated by the second light source unit and passing through the hole in the sheet.

[0024] Thus, it is not necessary to separately provide a light source unit and an inspection unit for detecting holes in a sheet material from the first light source unit, the first inspection unit, the second light source unit, and the second inspection unit for inspecting defects in the sheet material. Thus, according to the present invention, the number of components of the sheet material inspection device 1 can be reduced, thereby achieving space saving and cost reduction, and further reducing maintenance man-hours.

[0025] [Example 1]

[0026] Hereinafter, the sheet inspection device 1 according to the embodiment of the present invention will be described in more detail with reference to the drawings.

[0027] <Device Structure>

[0028] Figure 1 The main structure of the sheet inspecting device 1 of this embodiment is shown.

[0029] exist Figure 1 In the sheet conveying path T for conveying a sheet material such as a steel plate as a sheet-shaped material to be inspected, the sheet material is conveyed in a horizontal direction (from left to right on the paper). In addition, the sheet conveying path T has an extension along the width direction of the sheet material in a direction orthogonal to the conveying direction (from the front side of the paper surface to the back side in a direction orthogonal to the paper surface). Although not shown in the figure, the sheet material is supported by a conveying device such as a conveyor and conveyed along the sheet conveying path T.

[0030] The first light source unit Ls1 on the front side of the sheet (the upper side of the paper surface) is configured such that when the light irradiated from the first light source unit Ls1 to the sheet is incident at an angle of α degrees upward relative to the sheet conveying path T, the light (regular reflected light) incident from the first light source unit Ls1 and reflected by the sheet, that is, the light reflected at an angle of α degrees upward relative to the sheet conveying path T, is incident on the first inspection unit S1 on the front side of the sheet. In this way, the angles formed by the light path L11 from the first light source unit Ls1 to the sheet and the light path L12 of the light reflected from the sheet to the first inspection unit S1 relative to the vertical plane V (the plane perpendicular to the paper surface from the front side to the back side of the paper surface) orthogonal to the sheet conveying path T, that is, the angle of incidence θ11 and the angle of reflection θ12 are both 90 to α degrees, and are in mutually symmetrical positions. The sheet inspection device 1 described later inspects the presence or absence of a flaw as a defect on the front side of the sheet by detecting the light irradiated by the first light source unit Ls1 and reflected by the front side of the sheet using the first inspection unit S1. By configuring the first inspection unit S1 to detect the regular reflected light of the light irradiated by the first light source unit Ls1, it is possible to detect defects of the sheet with high accuracy. Here, the front side of the sheet corresponds to the "first side" of the present invention.

[0031] The second light source unit Ls2 on the back side of the sheet (the lower side of the paper) is configured so that the light irradiated from the second light source unit Ls2 to the sheet is incident at an angle of α degrees downward relative to the sheet conveying path T. In addition, the second inspection unit S2 on the back side of the sheet is configured so that the light (regular reflected light) incident from the second light source unit Ls2 and reflected by the sheet, that is, the light reflected at an angle of α degrees downward relative to the sheet conveying path T, is incident on the second inspection unit S2. In this way, the angles formed by the light path L21 from the second light source unit Ls2 to the sheet and the light path L22 from the light reflected by the sheet to the second inspection unit S2, that is, the angle of incidence θ21 and the angle of reflection θ22, are both 90 to α degrees relative to the vertical plane V orthogonal to the sheet conveying path T, and are in mutually symmetrical positions. The sheet inspection device 1 described later detects the light irradiated by the second light source unit Ls2 and reflected by the back side of the sheet through the second inspection unit S2, thereby inspecting the presence or absence of flaws as defects on the back side of the sheet. By configuring the second inspection unit S2 to detect regular reflected light of light irradiated by the second light source unit Ls2, defects of the sheet can be detected with high accuracy. Here, the back side of the sheet corresponds to the "second side" of the present invention.

[0032] Here, it is configured that when the light irradiated from the second light source unit Ls2 to the sheet passes through the front side due to the presence of a hole in the sheet, the light emitted from the second light source unit Ls2 is incident on the first inspection unit S1. In this way, in the sheet inspection device 1 described later, the presence or absence of holes as defects of the sheet is inspected by detecting the light irradiated by the second light source unit Ls2 and passing through the hole of the sheet by the first inspection unit S1. In the sheet inspection device 1 of the present embodiment, when θ11=θ12=θ21=θ22=10 degrees (α=80 ​​degrees), holes with a diameter of 0.1 mm or more in a sheet with a thickness of 0.25 mm can be well detected. θ11 (=θ12=θ21=θ22) is preferably 10±5 degrees, thereby being able to well detect holes in a sheet with a thickness of 0.20 to 0.30 mm. In addition, it is more preferable that θ11 (=θ12=θ21=θ22) is 10±1 degrees. In the above-described configuration, when there is a hole in the sheet, the light irradiated from the first light source unit Ls1 onto the sheet passes through the sheet and enters the second inspection unit S2 .

[0033] Thus, in this embodiment, the second light source unit Ls2 that irradiates light to the back of the sheet in order to inspect the defects on the back of the sheet also functions as a light source for inspecting the holes of the sheet, and the first inspection unit S1 for inspecting the defects on the front of the sheet also functions as a hole inspection unit for inspecting the holes of the sheet. Therefore, a separate light source and inspection unit for inspecting the holes of the sheet can be omitted. Thus, according to this embodiment, the number of components of the sheet inspection device 1 can be reduced, so that space saving and cost reduction can be achieved, and maintenance man-hours can be reduced.

[0034] Here, the first light source unit Ls1 and the second light source unit Ls2 are linear light sources extending in a direction perpendicular to the conveying direction (from the front side to the back side of the paper surface, in a direction perpendicular to the paper surface) in order to illuminate a sheet having a width in a direction perpendicular to the conveying direction. The linear light source may be, for example, a light source in which a plurality of LED elements are arranged in a direction perpendicular to the conveying direction and a diffusion plate is further provided, or may be a fluorescent lamp, but is not limited thereto.

[0035] The first inspection unit S1 and the second inspection unit S2 can use a line sensor camera having a field of view in a direction perpendicular to the conveying direction so as to detect light reflected from or transmitted through a sheet having a width in the direction perpendicular to the conveying direction.

[0036] Figure 2 1 is a functional block diagram of the sheet inspection device 1 according to the present embodiment.

[0037] The sheet material inspection device 1 includes an inspection section 11, an input signal processing section 12, a detection and determination processing section 13, and an output section 14. The inspection section 11 includes a first light source section Ls1, a first inspection section S1, a second light source section Ls2, and a second inspection section S2.

[0038] The input signal processing unit 12 processes the signals input from the first inspection unit S1 and the second inspection unit S2. For example, the input signal processing unit 12 includes an amplifier for amplifying the electrical signals input from the first inspection unit S1 and the second inspection unit S2, a filter for removing electrical noise, an AD converter, a processing unit for performing image processing, etc. As the input signal processing unit, a known technology can be appropriately adopted according to the structure of the inspection unit.

[0039] The detection and determination processing unit 13 detects and determines the presence and type of flaws and the presence or absence of holes based on the information output from the input signal processing unit 12. The detection and determination processing unit 13 can adopt a known technique as appropriate depending on the configuration of the inspection unit 11 and the input signal processing unit 12.

[0040] The input signal processing unit 12 and the detection and determination processing unit 13 can be constituted by a computer including a storage device such as a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). By expanding the program stored in the ROM and the like in a working area such as the RAM and executing it in the CPU, various functions that meet the prescribed purpose can be realized. In addition, the input signal processing unit 12 and the detection and determination processing unit 13 can also be realized by a dedicated circuit such as an FPGA or an ASIC.

[0041] The output unit 14 outputs the processing result of the detection and determination processing unit 13 to a display, a printer, a lamp, a buzzer or other reporting means, or a marking device that marks the occurrence position of a defect or a hole on the sheet.

[0042] <Modification>

[0043] In the above-mentioned sheet inspection device, when there are holes in the sheet, the presence of the hole in the sheet is inspected by the first inspection unit S1 detecting the light irradiated by the second light source unit Ls2 and passing through the hole in the sheet, but the presence of the hole in the sheet can also be inspected by the second inspection unit S2 detecting the light irradiated by the first light source unit Ls1 and passing through the hole in the sheet. In addition, the presence of the hole in the sheet can be inspected by using the result of the first inspection unit S1 detecting the light irradiated by the second light source unit Ls2 and passing through the hole in the sheet and the result of the second inspection unit S2 detecting the light irradiated by the first light source unit Ls1 and passing through the hole in the sheet.

[0044] It should be noted that, in order to enable comparison between the constituent elements of the present invention and the configurations of the embodiments, the constituent elements of the present invention are described below with reference numerals of the drawings.

[0045] <Invention 1>

[0046] A sheet material inspection device (1) is used to inspect defects of an inspected material. The sheet material inspection device (1) is characterized in that it comprises:

[0047] a first light source unit (Ls1) for irradiating a first surface of the sheet-shaped material to be inspected;

[0048] a first inspection unit (S1) for detecting reflected light of the light irradiated by the first light source unit (Ls1) and reflected by the first surface of the inspected material;

[0049] a second light source unit (Ls2) for illuminating a second surface of the inspected material; and

[0050] a second inspection unit (S2) for detecting reflected light of the light irradiated by the second light source unit (Ls2) and reflected by the second surface of the inspected material,

[0051] The first inspection unit (S1) is arranged at a position where, when a hole exists in the inspected material, the first inspection unit (S1) can detect light irradiated from the second light source unit (Ls2) and transmitted through the hole.

[0052] Description of symbols

[0053] 1: sheet material inspection device; 11: inspection unit; 12: input signal processing unit; 13: detection and determination processing unit; 14: output unit; Ls1: first light source unit; Ls2: second light source unit; S1: first inspection unit; S2: second inspection unit.

Claims

1. A sheet material inspection device for inspecting defects of an inspected material, the sheet material inspection device comprising: A first light source unit, which illuminates a first surface of the sheet-shaped material to be inspected; a first inspection unit configured to detect reflected light of the light irradiated by the first light source unit and reflected by the first surface of the inspected material; a second light source unit, which illuminates the second surface of the inspected material; a second inspection unit configured to detect reflected light of the light irradiated by the second light source unit and reflected by the second surface of the inspected material; as well as a detection and determination processing unit that determines the presence or absence of defects in the inspected material based on the signal input to the first inspection unit and / or the second inspection unit, The first inspection unit is arranged at a position where, when a hole exists in the inspected material, the first inspection unit can detect light irradiated from the second light source unit and transmitted through the hole. The detection and determination processing unit determines the presence or absence of the hole as the defect in the inspection target material using the light emitted from the second light source unit, transmitted through the hole, and detected by the first inspection unit.

2. The sheet material inspection device according to claim 1, characterized in that: The first inspection unit detects regular reflected light of the light irradiated by the first light source unit and reflected by the first surface. The second inspection unit detects regular reflected light of the light irradiated by the second light source unit and reflected by the second surface.

3. The sheet material inspection device according to claim 2, characterized in that: The incident angle of the light irradiated by the first light source unit and the reflection angle of the regular reflected light detected by the first inspection unit are both 10±5 degrees, The incident angle of the light irradiated by the second light source unit and the reflection angle of the regular reflected light detected by the second inspection unit are both 10±5 degrees.

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