JP2012047666A - Contour detection device for sheets - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the contour of sheets such as thin transparent plastic films or the overlapped state of the overlapped sheets.SOLUTION: This contour detection device for sheets includes: a roller 20 which rotates while its outer periphery 16 is brought into contact with a sheet 14 to be inspected; a support arm 26 for supporting the roller 20 to move to a direction 24 which is almost vertical to the face of the sheet 14; a conveyance device for making both the roller 20 and the sheet 14 move at the same time or either the roller 20 or the sheet 14 move to the direction of an arrow 33 so that a contact 28 of the roller 20 and the sheet 14 can relatively almost linearly move on the face of the sheet 14; an oscillation sensor 36 for detecting oscillation which occurs when the roller 20 passes through an edge 34 of the sheet 14 at the contact 28 of the roller 20 and the sheet 14; and a contour determination unit for accepting an output signal of the oscillation sensor 36 to determine an occurrence point of the oscillation as a portion of the contour of the sheet 14.

Description

  The present invention relates to a sheet contour detection apparatus that automatically detects the contour of a single sheet or a plurality of overlapping sheets.

  For an apparatus for nondestructive inspection of the shape or the like of an object, a method based on image analysis is frequently used (see Patent Document 1). In addition, an apparatus that blows gas to inspect the unevenness of an object has been developed (see Patent Document 2).

JP 2010-19762 A JP 2008-150069 A

The known prior art has the following problems to be solved.
The non-contact type inspection has an advantage that the object is not damaged compared with the contact type inspection. However, when thin transparent plastic films are overlapped and the overlapping state is detected, it is difficult to clearly distinguish the outline of the film even if the image is taken. It is conceivable to distinguish between the overlapped part and other parts by using an acoustic sensor such as an ultrasonic wave. However, when multiple thin plastic films are stacked and bonded without gaps, the overlapped part The difference in ultrasonic propagation characteristics between the other portions and the other portions is small, and the discrimination is not easy.
In order to solve the above-described problems, the present invention provides a sheet contour detection apparatus capable of quickly and reliably detecting the contour of a sheet such as a thin transparent plastic film and the overlapping state of overlapping sheets. For the purpose.

The following configurations are means for solving the above-described problems.
<Configuration 1>
A roller that rotates while being in contact with the outer periphery of the sheet to be inspected, a support arm that movably supports the roller in a direction substantially perpendicular to the surface of the sheet, and a contact point between the roller and the sheet includes the surface of the sheet. A conveying device that moves the roller and the sheet at the same time or one of the roller or the sheet so that the roller and the sheet move relatively linearly, and the roller rolls in contact with the sheet. A contour sensor that detects a vibration generated when passing through an edge, and an output signal of the vibration sensor, and determines the vibration generation point on the straight line as a part of the contour of the sheet. An apparatus for detecting a contour of a sheet, comprising: a section.

<Configuration 2>
2. The sheet contour detection apparatus according to claim 1, wherein the sheet is a transparent sheet.

<Configuration 3>
In the sheet contour detection apparatus according to Configuration 1 or 2, the sheet is obtained by bonding a sheet having a small area onto a sheet having a large area so that the sheet has a small area. An apparatus for detecting a contour of a sheet, wherein the position of an edge of the sheet having a small area on the sheet is determined.

<Configuration 4>
4. The sheet contour detection apparatus according to any one of configurations 1 to 3, wherein the sheet thickness is 1 mm or less and 0.01 mm or more.

<Configuration 5>
4. The sheet contour detection apparatus according to any one of configurations 1 to 3, wherein a metal roller having an outer diameter of 10 mm or less and 2 mm or more is used.

<Configuration 6>
6. The sheet contour detection device according to any one of Structures 1 to 5, wherein a plurality of rollers whose rotation axes are directed in the same direction or parallel to each other are respectively supported by the support arms, and each of the rollers and the sheet A plurality of vibration sensors provided for each roller and the output signals of the plurality of vibration sensors so as to detect vibrations generated when the rollers pass the edge of the sheet at the contact points An apparatus for detecting a contour of a sheet, comprising: a contour discriminating unit that obtains the vibration generation point on the straight line and determines the contour of the sheet by connecting the vibration generation points.

<Effect of Configuration 1>
If the roller rolls almost linearly on the surface of the sheet and detects the vibration generated when the roller passes through the edge of the sheet, the contour can be reliably discriminated whether it is a very thin sheet or a transparent sheet.
<Effect of Configuration 2>
Since the transparent sheet is not particularly easy to detect the contour, the configuration of this apparatus functions effectively.
<Effect of Configuration 3>
A sheet having a small area is in close contact with a sheet having a large area, and even when both sheets are transparent or the same color, the contour can be reliably determined.
<Effect of Configuration 4>
Even when the thickness of the sheet is 1 mm or less and as thin as 0.01 mm, the contour can be reliably determined.
<Effect of Configuration 5>
In order to detect the level difference of the edge of a thin sheet, a roller having an outer diameter of 10 mm or less and 2 mm or more is suitable.
<Effect of Configuration 6>
If the edge of the sheet is detected by a plurality of rollers, the outline and orientation of the entire sheet can be simultaneously determined.

It is a perspective view which shows the principal part Example of the outline detection apparatus of a sheet | seat. It is a side view showing the relationship between a roller and a sheet during contour detection. (A) is explanatory drawing which shows the relationship between the four straight lines which four rollers pass, the edge of a sheet | seat, and the output signal of a vibration sensor, (b) is explanatory drawing for discriminating the outline of a sheet | seat. It is a functional block diagram of the circuit which processes the output signal of a vibration sensor. FIG. 5 is a hardware block diagram when the circuit shown in FIG. 4 is realized by a computer.

  Hereinafter, embodiments of the present invention will be described in detail for each example.

FIG. 1 is a perspective view showing an embodiment of a main part of a sheet contour detecting apparatus 10.
The illustrated apparatus is installed in a conveyance path for conveying the sheet 14 in the direction of arrow 33. In the sheet of this example, two polyethylene films having a thickness of 0.05 mm are stacked and bonded with an adhesive. The lower film is trapezoidal. The upper film is a thin strip. If both are bonded as shown in the figure, it is a non-defective product. If the upper film is bent and adhered, it is excluded from the line as a defective product. It can also be applied to the case where the film is welded by heat.

  The sheet outline detection device 10 is used for this quality inspection. Here, the lower film is referred to as a sheet 14A, and the upper film is referred to as a sheet 14B. The apparatus of this embodiment includes four rollers 20. These rollers 20 rotate while rolling while contacting the outer periphery of the surface 22 of the sheet 14 to be inspected. The rotation shaft 18 of each roller 20 is fixed to a support arm 26. Each roller 20 is movably supported by a support arm 26 in a direction substantially perpendicular to the surface 22 of the sheet 14 (arrow 24 direction). That is, the support arm 26 is supported by the support shaft 27 oriented in the direction orthogonal to the arrow 33 and is configured to swing its free end.

  When the sheet 14 is conveyed in the direction of arrow 33 by a belt conveyor or the like (not shown), the contact point 28 between the roller 20 and the sheet 14 moves linearly on the surface of the sheet 14. The conveying device may be driven so that both move relatively linearly. The roller 20 and the sheet 14 may be moved simultaneously. One of the roller 20 or the sheet 14 may be moved.

  A vibration sensor 36 is fixed to the support arm 26 adjacent to the portion where the roller 20 is attached. The vibration sensor 36 has a function of detecting vibration generated when the roller 20 passes the edge of the sheet 14 at a contact point between the roller 20 and the sheet 14. In the illustrated example, the sheet 14A has an edge 34A and an edge 34D. The sheet 14B has an edge 34B and an edge 34C. The vibration sensor 36 detects all vibrations when passing through them. A wiring 37 formed on the support arm 26 is connected to the vibration sensor 36. An output signal of the vibration sensor 36 is sent to the contour discriminating unit (not shown) through the wiring 37.

  The contour discriminating unit receives the output signal of the vibration sensor 36 and discriminates the generation point of the vibration on the straight line as a part of the contour of the sheet 14. The circuit configuration will be described later with reference to FIG. If the roller 20 rolls almost linearly on the surface of the sheet 14 and detects the vibration generated when the roller 20 passes through the edge of the sheet 14, the contour can be reliably discriminated whether it is a very thin sheet or a transparent sheet.

FIG. 2 is a side view showing the relationship between the roller and the sheet during contour detection.
An example of the sheet edge detection method will be described with reference to FIG. As shown in the figure, in this embodiment, a sheet 14B having a small area is in close contact with a sheet 14A having a large area. Both are bonded by an adhesive or the like. Moreover, all the sheets are transparent sheets. Therefore, it is difficult to recognize the contour in image processing. It is difficult to detect the overlap of two sheets even with a transmissive optical sensor or an ultrasonic sensor.

  However, according to the apparatus of the present invention, these overlaps can be detected accurately. As shown in the figure, the roller 20 moves relatively to the right side on the sheet 14 toward (a) to (e). When the roller 20 rides on the edge 34B of the sheet 14B as shown in (b), the vibration is detected. Further, as shown in (d), the vibration is detected when the roller 20 descends at the edge 34C of the sheet 14B. When the sheet 14A is placed on a flat conveyor, the edge 34A and the edge 34D of the sheet 14A are detected in exactly the same manner.

FIG. 3A is an explanatory diagram illustrating the relationship between the four straight lines 30A, 30B, 30C, and 30D through which the four rollers 20 pass, the edges of the sheets 14A and 14B, and the output signal of the vibration sensor 36. is there.
As shown in the figure, for example, the roller 20 passing the straight line 30A in the figure detects the positions of the edge 34A of the sheet 14A, the edge 34B of the sheet 14B, the edge 34C, and the edge 34D of the sheet 14A in this order. The output signal 38A is output.

  The roller 20 passing through the straight line 30B in the figure outputs an output signal 38B. The roller 20 passing through the straight line 30C in the figure outputs an output signal 38C. The roller 20 passing through the straight line 30D in the figure outputs an output signal 38D. As a result, the contours of the sheets 14A and 14B can be determined by analyzing the detection timing of these output signals. In the above example, two sheets are targeted, but even when three or more sheets are overlapped, the edge can be similarly determined.

FIG. 3B is an explanatory diagram for determining the outline of the sheet.
As can be seen from FIGS. 2B and 2D, the roller vibrates not directly above the edges 34B and 34C of the sheet 14B. Therefore, it is necessary to correct the actual edge detection position of the sheet. As shown in FIG. 3 (b), when the sheet thickness is W and the outer diameter of the roller is R, when both are overlaid, the length corresponding to the overlapping portion G in the figure is corrected to be subtracted, The position of the sheet edge, the exact width, etc. can be detected.

  With the apparatus of the embodiment described with reference to FIG. 1, it can be determined whether the sheet 14B is correctly attached as shown by the solid line in FIG. 3A or bent and attached as shown by the broken line in FIG. . Further, the position where the sheet 14B is attached can be detected accurately. That is, the above-described apparatus can be used for both or one of the determination of the bending of the sheet edge and the accurate position determination. According to an experiment, when the thickness of the sheet is as thin as 1 mm to 0.01 mm, a roller having an outer diameter of 10 mm to 2 mm is suitable for detecting the step of the edge of the sheet without error. all right.

  When the thickness of the sheet exceeds 1 mm, it can be sufficiently detected even with a relatively large diameter roller. Further, the thickness of the sheet can be detected with an optical sensor. In addition, when the thickness of the sheet is less than 0.01 mm, the vibration of the roller is weak, and the vibration detection mechanism and circuit may be expensive. If the outer diameter of the detection roller is 10 mm or less, the vibration at the time of detecting the step is remarkable, and a vibration detector and an analysis circuit can be obtained at low cost. When the outer diameter of the roller is less than 2 mm, the roller may jump up at the edge of the sheet. Accordingly, the outer diameter of the roller is preferably 10 mm or less and 2 mm or more.

FIG. 4 is a functional block diagram of a circuit that processes the output signal of the vibration sensor 36.
As shown in the figure, the analog signal output from the vibration sensor 36 is converted into a digital signal by the A / D converter 40. Then, the waveform analysis unit 44 analyzes the waveform in order to determine the timing at which the sheet edge is detected. The edge of the sheet may be, for example, the timing when the maximum value of the input waveform is detected. An output signal from the waveform analysis unit 44 and a signal for controlling the conveying device 32 are input to the contour determination unit 46. This is because the conveyance speed and the edge detection timing are synchronized.

  In the embodiment shown in FIG. 1, output signals after waveform analysis of the four vibration sensors 36 are input to the contour determination unit 46. Thereby, it is possible to determine the bending of the sheet and the attachment position of the sheet. The determination result 48 is output from the speaker 50. For example, the speaker 50 emits a buzzer sound to notify the operator when a sheet bending or misalignment is detected. An apparatus such as an arm (not shown) that automatically removes the sheet from the conveyance path may be driven. The circuit shown in FIG. 4 can be realized by combining a microcomputer and a simple digital integrated circuit.

FIG. 5 is a hardware block diagram when the circuit shown in FIG. 4 is realized by a computer.
A CPU (Central Processing Unit) 111, a ROM (Read Only Memory) 112, a RAM (Random Access Memory) 113, and an input / output interface 115 are connected to the internal bus 110 of the computer 100. A display 117, a printer 118, a mouse 119, and a keyboard 120 are connected to the input / output interface 115. Furthermore, the input / output interface 115 is connected to the A / D converters 32 of the four vibration sensors 36, the transport device 32, and the speaker 50.

  The waveform analysis unit 44 and the contour determination unit 46 are realized by a computer program. That is, the functions are realized by the CPU 111, the ROM 112, the RAM 113, and the like. The determination result 48 is stored in the RAM 113. A display 117 and a printer 118 are used for display output of processing results, and a mouse 119 and a keyboard 120 are used for control of the apparatus.

  As described above, if a plurality of rollers 20 whose rotation axes are directed in the same direction or parallel to each other are supported by the support arm 26, each roller 20 is a sheet 14 at the contact point between each roller 20 and the sheet 14. It is possible to detect vibrations that occur when passing through the edge of the. As a result, the plurality of vibration sensors 36 provided for each roller and the output signals of the plurality of vibration sensors 36 are received, the generation points of vibrations on a straight line are obtained, and the generation points of the vibrations are connected to each other to outline the sheet. Can be determined.

DESCRIPTION OF SYMBOLS 10 Sheet outline detection apparatus 14 (A, B) Sheet 16 Outer periphery 18 Rotating shaft 20 Roller 22 Sheet surface 24 Vertical direction 26 Support arm 27 Support shaft 28 Contact 30 (A, B, C, D) Straight line 32 Conveyance device 33 Arrow 34 (A, B, C, D) Edge 36 Vibration sensor 37 Wiring 38 Output signal 40 (A, B, C, D) A / D conversion unit 42 Contour data 44 Waveform analysis unit 46 Contour discrimination unit 48 Discrimination result 50 Speaker 100 Computer 110 Internal bus 111 CPU
112 ROM
113 RAM
115 Input / Output Interface 117 Display 118 Printer 119 Mouse 120 Keyboard

Claims (6)

A roller that rotates while contacting the outer periphery of the sheet to be inspected, and
A support arm that movably supports the roller in a direction substantially perpendicular to the surface of the sheet;
A conveying device that moves the roller and the sheet simultaneously or one of the roller or the sheet so that the contact point of the roller and the sheet moves relatively linearly on the surface of the sheet;
A vibration sensor for detecting vibration generated when the roller passes through the edge of the sheet while rolling in contact with the sheet;
An apparatus for detecting a contour of a sheet, comprising: a contour determining unit that receives an output signal of the vibration sensor and determines a generation point of the vibration on the straight line as a part of the contour of the sheet. The contour detection apparatus for a sheet according to claim 1,
The sheet outline detecting apparatus, wherein the sheet is a transparent sheet. In the sheet contour detection apparatus according to claim 1 or 2,
The sheet is formed by adhering a sheet having a small area on a sheet having a large area, and the contour determination unit determines a position of an edge of the sheet having the small area on the sheet having a large area. An apparatus for detecting a contour of a sheet, characterized by discriminating. In the outline detection apparatus of the sheet according to any one of claims 1 to 3,
An apparatus for detecting a contour of a sheet, wherein the sheet has a thickness of 1 mm or less and 0.01 mm or more. In the outline detection apparatus of the sheet according to any one of claims 1 to 3,
A sheet contour detection apparatus using a metal roller having an outer diameter of 10 mm or less and 2 mm or more. In the sheet contour detection device according to any one of claims 1 to 5,
A plurality of rollers whose rotation axes are directed in the same direction or parallel to each other are supported by the support arms, respectively.
A plurality of vibration sensors provided for each roller so as to detect vibrations generated when the rollers pass the edge of the sheet at the contact points between the rollers and the sheet;
A contour determining unit that receives output signals of the plurality of vibration sensors, obtains the vibration generation point on the straight line, and determines the contour of the sheet by connecting the vibration generation points; Sheet contour detection device.

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