JP2000019128A - Foreign matter inspection device for transparent film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foreign matter inspection device for a transparent film having little possibility of inspection omission of foreign matter in a transparent film on the roughly whole surface at a high speed. SOLUTION: This inspection device has an optical sensor detection means 14 having photdiodes 19a for detecting a foreign matter defect formed inside a test object, namely, a transparent film 1 with roughly the same visual field width as the size of the foreign matter, and a quality determination means for measuring the size of the foreign matter detected by the optical sensor detection means 14 and for determining the quality of the foreign matter from the measured size. In the optical sensor detection means 14, the photodiodes 19a are installed in roughly a lattice shape with a prescribed spacing by being arranged plurally in the longitudinal and lateral directions, and a conveyance line part for moving the longitudinal and lateral arrangement directions in the inclined state against a relative moving direction with the transparent film 1 is installed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent film foreign matter inspection apparatus.

[0002]

2. Description of the Related Art Today, various transparent films are used in various fields of industry. Such a transparent film is subjected to a quality inspection such as a foreign substance inspection at the time of manufacture in order to confirm whether or not a predetermined quality requirement is satisfied.

[0003] As a conventional transparent film quality inspection apparatus, there is a fish eye inspection apparatus as disclosed in Japanese Patent Application Laid-Open No. 6-242023.

That is, as shown in FIG. 8, a line extending vertically in the width direction of the transparent film 1 vertically from below to a lower surface of the transparent film 1 in the middle of a film transport line for transporting the strip-shaped transparent film 1. Light 2 is provided. The linear light 2 is composed of a plurality of optical fibers arranged so that the end faces thereof are straight, so that a line beam close to a parallel light beam can be emitted.

A one-dimensional CCD capable of receiving transmitted light emitted from the linear light 2 and transmitted through the transparent film 1 is provided at a position directly above the linear light 2 across the transparent film 1 in the film transport line. Camera 3
It is arranged so that the viewing direction is perpendicular to the line beam illuminating portion. The one-dimensional CCD camera 3 is arranged such that the light receiving element array 4 provided inside is oriented in the width direction of the transparent film 1, and the one-dimensional CCD camera 3 includes a foreign matter defect 5 (see FIG. 9) to be measured. It is set to have a high resolution of 1/3 or less of the minimum one. In addition, the one-dimensional CCD camera 3 has a field of view covering the entire width of the transparent film 1.

Here, the foreign matter defect 5 will be described. In general, in the manufacturing process of the transparent film 1, optical distortion called fish-eye-like shape may be generated inside the transparent film 1. In most of the fish eyes, the bubble portion 7 is formed around the core portion 6, and among them, the foreign matter 8 becomes the core portion 6, which is the foreign matter defect 5. In addition, the fish eye in which the gel, which is a component of the transparent film 1, becomes the core 6 is treated as not having the foreign matter defect 5. In addition, although there are rare fish eyes including only the bubble portion 7, this case is also treated as not having the foreign matter defect 5.

The one-dimensional CCD camera 3 is connected to an image processing device 9 for counting the number of fish eyes, and the image processing device 9 sets a test condition and displays a result of the test. And the like.

[0008] In this configuration, the linear light 2 extending in the width direction of the transparent film 1 is used in parallel with the belt-shaped transparent film 1 being fed through the film transport line from below to the lower surface of the transparent film 1. A line beam close to a light beam is irradiated vertically.

Then, the transmitted light emitted from the linear light 2 and transmitted through the transparent film 1 is received by the light receiving element array 4 of the one-dimensional CCD camera 3 vertically arranged right above the linear light 2. .

The video signal from the one-dimensional CCD camera 3 is sent to an image processing device 9 which counts the number of fish-eye shaped optical distortions called fish eyes based on the video signal. I do.

Thereafter, an arithmetic processing unit 10 such as a computer inspects the fish eyes counted by the image processing unit 9 to determine whether the core 6 is a gel or a foreign substance 8 and displays the result.

In the above fisheye inspection apparatus, the core 6
As shown in FIG. 10, the image of the fish eye of the gel has two thin shadows 1 １ ／ of the size of the fish eye.
1 is reflected away in the line direction.

This is because, at the peripheral portion of the bubble portion 7 of the fish eye, the transmitted light is refracted due to optical distortion, the amount of received light is reduced, and the shadow is detected as a dark shadow 11, whereas the central portion of the fish eye is detected. The reason for this is that the amount of received light did not decrease because of small optical distortion and the use of a line beam close to parallel rays.

Further, the image of the fish eye of the foreign material 8 whose core 6 is a foreign material dark shadow 12 is shown in the center of the two thin shadows 11 as shown in FIG. this is,
This is because light transmission is blocked at the portion of the foreign matter 8 at the center of the fish eye.

Therefore, by increasing the resolution of the one-dimensional CCD camera 3 to one third or less of the minimum one of the foreign matter defects 5 to be measured, the detection of fish eyes and the nucleus part 6 of gel The fish eye and the core 6 can be distinguished from the fish eye of the foreign matter 8.

[0016]

However, in such a conventional fisheye inspection apparatus, a one-dimensional CCD is used.
By increasing the resolution of the camera 3 to 1/3 or less of the minimum one of the foreign matter defects 5 to be measured, the fish eye is detected, and the nucleus 6 is a gel fish eye and the nucleus 6 is Since the fish eyes of the foreign matter 8 are distinguished from each other, an expensive one-dimensional CCD camera 3 is required. In addition, when the resolution of the one-dimensional CCD camera 3 is set to be higher, the field of view of the one-dimensional CCD camera 3 is correspondingly narrowed. Camera 3
However, there is a problem that a plurality of devices are required, which leads to an increase in cost.

On the other hand, in order to avoid cost increase,
If the resolution of the one-dimensional CCD camera 3 is set lower than the above, the core 6 and the bubble 7 cannot be clearly imaged, and the core 6 is a gel fish eye and the core 6 is a foreign matter 8.
Cannot be distinguished from fish eyes.

Moreover, the field of view M of the one-dimensional CCD camera 3
It is known that No. 1 becomes narrower as shown by the two-dot chain line in the figure with the improvement of the resolution. The main body portion 3a of the one-dimensional CCD camera 3 has a predetermined size L1 as shown in FIG. 12, for example, a gap S1 between the visual field widths M2 and M2 over substantially the entire width direction H of the transparent film 1. It is difficult to inspect the entire surface of the transparent film even if they are arranged side by side so as to minimize or eliminate
When there exists, there exists a possibility that it may not be detectable.

For example, the one-dimensional CCD camera 3 is
Although reciprocating along substantially the entire width direction H of the transparent film 1 or scanning using a laser beam can be considered, a predetermined time is required to inspect the entire surface, and the flow direction of the transparent film 1 is required. It was difficult to improve the speed.

Therefore, an object of the present invention is to solve the above-mentioned problems, to reduce the possibility of an inspection omission even when the resolution is improved, and to perform a high-speed inspection of foreign substances on a transparent film over substantially the entire surface. An object of the present invention is to provide an apparatus for inspecting a foreign substance of a transparent film.

[0021]

According to the first aspect of the present invention, there is provided a method for solving the above-mentioned problems, wherein a foreign substance formed inside a transparent film to be inspected is reduced in size and substantially to the size of the foreign substance. An optical sensor detecting means having a micro area optical sensor for detecting with the same field of view width, and a good or bad determining means for determining the type of the foreign matter from the measured value of the foreign matter detected by the optical sensor detecting means, The optical sensor detecting means is provided with a plurality of the micro-area optical sensors arranged at predetermined intervals, and provided with a relative moving portion in which the arrangement direction is inclined with respect to the relative moving direction with respect to the inspection object. It features a film foreign matter inspection device.

According to the first aspect of the present invention, the arrangement direction of the plurality of micro-region optical sensors arranged at predetermined intervals by the relative moving portion of the optical sensor detecting means is set to be the same as the above. The relative movement is performed while being tilted with respect to the inspection object.

For this reason, even if a high-resolution micro-region optical sensor having a small visual field width of the optical sensor is provided at a predetermined interval,
The distance between the visual fields of the adjacent small area optical sensors is made closer to each other with an inclination to the relative movement direction. For example, by arranging the size of the inspection object in the width direction / the visual field width of one micro area sensor = the number (number) of the micro area sensors in the width direction of the inspection object, The gap between the widths can be eliminated. Therefore, even if the resolution is improved, there is little possibility that the inspection will be missed, and it is possible to inspect foreign substances at high speed over the entire surface of the transparent film.

According to the second aspect of the present invention, there is provided a micro-area optical sensor for detecting a foreign substance formed inside a transparent film to be inspected with substantially the same visual field width as the size of the foreign substance. Optical sensor detection means having, and good or bad judgment means to measure the size of the foreign matter detected by the light sensor detection means and determine the quality of the foreign matter from the measured dimensions,
The optical sensor detecting means is provided with a plurality of the micro area optical sensors arranged in a vertical and horizontal direction at a predetermined interval in a substantially lattice shape, and tilts the vertical and horizontal arrangement directions with respect to a relative movement direction with respect to the inspection object. And a foreign matter inspection device for a transparent film provided with a relative moving portion.

According to the second aspect of the present invention, a plurality of micro-area optical sensors of the optical sensor detecting means are arranged in a substantially lattice pattern at predetermined intervals in the vertical and horizontal directions. While the vertical and horizontal arrangement directions are inclined with respect to the direction of relative movement with respect to the inspection object, they are relatively moved by the relative moving unit.

For this reason, even if a high-resolution micro-area optical sensor having a small field-of-view width of the optical sensor is provided at a predetermined interval, the distance between the visual fields of the adjacent micro-area optical sensors is inclined with respect to the relative movement direction. , And arranged in the vertical direction, so that the number of micro-area optical sensors provided within a predetermined width can be increased.

According to the third aspect,
The relative moving unit is provided with a transport line unit for transporting and moving the transparent film along the longitudinal direction, and a housing in which the micro area optical sensors are arranged at predetermined intervals is arranged in the flow direction of the transport line unit. A foreign matter inspection device for a transparent film according to claim 1 or 2, which is fixed by being inclined with respect to the transparent film.

According to the third aspect of the present invention, the housing in which the small area optical sensors are arranged at predetermined intervals is fixed at an angle with respect to the flow direction of the transport line. The transparent film transported and moved by the transport line unit is inspected in the width direction over substantially the entire width.

For this reason, even if the transparent film is given a predetermined speed of passing through the casing, each of the minute area sensors only needs to inspect the inside of a predetermined minute area. Inspection can be performed over the entire surface, and the inspection process can be sped up.

According to another aspect of the present invention, the micro-area optical sensor of the optical sensor detecting means includes an illuminating means for vertically irradiating one side surface of the transparent film with light, A first minute area optical sensor which is provided at a position facing the illuminating means on the side surface and directs the viewing direction in a vertical direction with respect to the illuminated portion; 4. The apparatus for inspecting foreign matter in a transparent film according to claim 1, further comprising: a second minute area optical sensor for providing a predetermined angle from a vertical direction to the portion and directing the viewing direction. .

According to the fourth aspect of the present invention, the illuminating means is provided on the other side of the illuminating means with the transparent film interposed therebetween, and is provided at a predetermined angle from the vertical direction with respect to the irradiated portion. A second micro-area optical sensor for directing a visual field direction detects optical distortion of an irradiated portion of the transparent film. For this reason, for example, it is possible to determine whether bubbles or the like are formed around the foreign matter.

In addition, the first side of the transparent film
Even if the micro-area optical sensor and the second micro-area optical sensor are provided, the arrangement direction is tilted, so that the field of view is made close to and substantially zero by setting the field of view width close to substantially zero. Can be simultaneously performed while discriminating the types of a plurality of foreign substances, and the inspection process can be further speeded up.

Further, according to the present invention, in the quality judgment means, the light quantity detected by the second minute area optical sensor is smaller than the refracted light generated by optical distortion in the presence of foreign matter. 5. The apparatus according to claim 4, wherein the type of the foreign matter is determined by comparing the quality of the foreign matter with a preset value for determining the quality of the foreign matter, which is a dark value and a value brighter than the light amount in the non-defective state. .

According to the fifth aspect of the present invention, the light quantity detected by the second micro area optical sensor is compared with a pass / fail judgment reference value preset in the pass / fail judgment means. If the value is darker than the refracted light generated by optical distortion in the presence of foreign matter, and the value is brighter than the amount of light in the non-defective state, the type of foreign matter is specified.
For example, the center nucleus is determined to be a gel fisheye.

[0035]

Embodiment 1 Hereinafter, a specific embodiment 1 of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show a first embodiment of the present invention.
It shows. Parts that are the same or equivalent to those in the conventional example will be described with the same reference numerals.

First, the structure will be described. The foreign matter inspection apparatus for a transparent film according to the first embodiment employs a so-called transmission illumination system in which a transparent film 1 used as a protective film for a photomask used in manufacturing a printed wiring board is used. An illumination means 13 for vertically irradiating light to one side 1a of the transparent film 1 as an object to be inspected, and an illumination means 13 for the other side 1b of the transparent film 1. An optical sensor detecting means 14 provided at a position facing the optical sensor; a good / bad determining means 15 for measuring the size of the foreign matter detected by the optical sensor detecting means 14 to determine the quality of the foreign matter based on the measured dimensions; Relative movement provided in the detecting means 14 to move the transparent film 1 in the longitudinal direction while tilting the arrangement direction with respect to the relative movement direction of the transparent film 1 A conveying line portion 16 as are provided.

In the illuminating means, a light source casing 18 having a substantially rectangular flat plate shape is provided in parallel at a predetermined interval below the transparent film 1 flowing through the transport line section 16. On the upper surface side of the light source housing 18, a plurality of light source blocks 17 are opposed to each other so that the infrared irradiation direction is vertical to the one side surface 1a, and have a substantially lattice shape at a predetermined interval. As shown in FIG.
The arrangement pitch of the light source blocks 17, 17 is set to 10 mm in the film flow direction, which is the vertical direction, and in the film width direction, which is the horizontal direction. These light source blocks 17...
And a total of 12,000 pieces of 120 pieces in the film width direction. 1 and 3, for the sake of description, the light source blocks 17 are described as being arranged in a total of 120 light source blocks 17 in the film flow direction and 12 in the film width direction.

The light source block 17 includes an infrared light emitting diode body 17a as a light source for emitting infrared light.
And, when the infrared light emitting diode body 17a and the one side surface 1a are interposed between the infrared light emitting diode body 17a and the transparent film 1, the effective field width irradiated by the infrared light is 0.1 m.
The lens unit 17b that converges infrared rays so as to set m is provided for each small case 17c.

The light source housing 18 itself is fixed at an angle of α = 0.57 ° with respect to the flow direction of the transparent film 1 so that the flow of the transparent film 1 of the infrared light emitting diode main bodies 17 a. The arrangement of the directions is also inclined by α1 = 0.57 degrees with respect to the flow direction of the transparent film 1.

The optical sensor detecting means 14 is provided with a sensor housing 20 having a substantially rectangular flat plate shape.
Are provided above the transparent film 1 flowing in parallel at predetermined intervals. A plurality of sensor blocks 19 are provided on the lower surface side of the sensor housing 18 so that the infrared light receiving direction is perpendicular to the other side surface 1b.

The sensor block 19 serves as a small area optical sensor main body for detecting the foreign matter 8 formed inside the transparent film 1 to be inspected with substantially the same visual field width as the size of the foreign matter 8. A photodiode 19a;
A lens 19b interposed between the minute area optical sensor 19a and the other side surface 1b and condensing light within an effective visual field width of 0.1 mm irradiated by the infrared ray that has reached the transparent film 1 is small. Each set is stored in the case 19c,
A plurality of them are arranged in the vertical and horizontal directions so as to have a substantially lattice shape at predetermined intervals.

The arrangement pitch of the sensor blocks 19 is set to 10 mm in the longitudinal direction of the film and in the lateral direction of the film. Then, 100 of these sensor blocks 19 are arranged in the film flow direction and 120 in the film width direction.
The light source block 17 is arranged so as to oppose each light source block 17 with the transparent film 1 interposed therebetween. 1 and 3 for explanation.
10 sensor blocks 19 in the film flow direction,
And 12 are arranged in the film width direction in total of 120.

The sensor housing 20 itself is fixed at an angle α2 = 0.57 ° with respect to the flow direction of the transparent film 1 so that the photodiode 1 is fixed.
The arrangement of 9a in the direction of flow of the transparent film 1 is also inclined by α1 = 0.57 degrees with respect to the direction of flow of the transparent film 1.

In the first embodiment, the size of the minimum inspection standard for use as a protective film for the photomask of the foreign matter 8 is about 50 μm, so that the effective visual field width of 0.1 mm which exhibits a resolution of substantially the same order. Is used. Further, the transfer line unit 1
The 6-line speed is 40 m / min, and the width of the transparent film 1 is about 1200 mm or less.

The photodiode 19 a is connected via a A / D converter 23 to a pass / fail judgment device 22 of a pass / fail judgment means 15 for judging the presence / absence of a foreign substance from the detected light quantity of the foreign substance.

The pass / fail determination device 22 includes a storage section 24 for storing a predetermined light quantity lower than the quantity of light in a state where there is no normal foreign matter as a pass / fail determination reference value b, and the A / D converter 23.
Is compared with the pass / fail judgment reference value b stored in the storage unit 24, and the light amount lower than the pass / fail judgment reference value b stored in the storage unit 24 is reduced by any one of the photodiodes 19a. When any one of... Is detected, a foreign object detection position is calculated based on speed information from a central processing unit 25 which determines that the product is defective and speed information from a film speed detector 26 provided on the transport line unit 16. A timing controller unit 28 that outputs position correction information to the central processing unit 25 and outputs a rotation speed correction signal to a drive motor 27 provided in the transport line unit 16, and outputs a defective product location. It mainly comprises a result output unit 29 for displaying on a monitor 30 or the like connected thereto.

Next, the operation of the first embodiment will be described with reference to the flowchart of FIG.

In the first embodiment, when the inspection is started in Step 1, the driving of the driving motor 27 provided on the transport line section 16 of the optical sensor detecting means 14 is performed.
The transparent film 1 moves along the longitudinal direction. This movement is performed relatively while the arrangement direction of the plurality of photodiodes 19a arranged at predetermined intervals is inclined with respect to the transparent film 1 by a predetermined angle α2.

For this reason, even if a high-resolution photodiode 19a having a small visual field width is provided at a predetermined interval as an optical sensor, the distance between the visual fields of the photodiodes 19a is close to each other with the inclination α relative to the relative movement direction. For example,
As shown in FIG. 3, the size r of the inspection object in the width direction / the visual field width of one photodiode 19a = photodiode 1
By arranging n photodiodes 19a in the number (pieces) 9a in the range r in the width direction of the inspection object, it is possible to eliminate the gap between the field widths. Here, for simplicity of explanation, as shown in FIG.
Are arranged in a total of n × m = 120, where n = 10 in the film flow direction and m = 12 in the film width direction, and n
The positions of × m arbitrary sensors are p (i, j) (1 ≦ i
≦ m, 1 ≦ j ≦ n), n × m photodiodes 19a of p (i + 1) and p (i + 1, n) are arranged at the same position,
The inclination α1 = α2 = 0.57 degrees is set and fixed.

For this reason, in the case shown in FIG. 3, when calculation is performed with r × the number of columns m = 120 mm, the field width = 1 mm, and the number m = 12 arranged in the horizontal direction, n = 120/12/1 =
If ten sensor blocks 19 are arranged in the vertical direction along the flow direction, the gap amount can be made zero.

In the first embodiment, α1 = α2 = 0.
57 degrees, r × the number of rows m = 1200 mm, field width =
When the calculation is performed with 0.1 mm and the number m = 120 arranged in the horizontal direction, n = 1200/120 /
By arranging 0.1 = 100 sensor blocks 19 having photodiodes 19a having a visual field width of 0.1 mm in the vertical direction along the flow direction, the gap amount can be set to 0 and the inspection omission can be eliminated.

Further, m = 12 columns are arranged in the vertical direction,
Photodiode 1 provided within a predetermined width of 1200 mm
9a can be increased to 12,000 pieces.

An analog signal of the amount of light detected by these photodiodes 19a is sent to the A / D converter 23, where it is converted into a digital signal, and a signal value g indicating the brightness after the conversion. (Step 2).

In the pass / fail judgment device 22, the signal value g
Is compared with the pass / fail judgment reference value b stored in the storage unit 24 (Step 3).

When there is no foreign matter 8 on the transparent film 1, the reference value b for good or bad is set to the signal value g.
Since the light amount exceeds the threshold value, it is determined that the quality is good when g> b (Step 4). Further, when the foreign substance 8 exists on the transparent film 1, the light amount is reduced and the signal value g does not exceed the pass / fail judgment reference value b. For this reason, in the pass / fail determination device 22, if g <b, even at one location, it is determined as a defective product (Step 5).

Therefore, by using the lenses 17b and 19b to limit the area to be measured and improving the resolution, the width of the field of view is narrowed, or the field of view is inexpensive, and the field of view is the unit width of the sensor. Even if the photodiode 19a having a width smaller than the width of the sensor block 19 and the infrared light emitting diode main body 17a are used in combination, there is little possibility that an inspection leak will occur, and the transparent film 1 is transported at high speed over the entire surface of the transparent film 1 by the transport line section 16. Inspection of the presence or absence of the foreign matter 8 can be continuously performed while conveying 1.

Further, even if a predetermined speed of 40 m / min passing through the sensor housing 20 is given by the transport line section 16, each of the photodiodes 19a
However, only by individually inspecting a predetermined minute area, an inspection can be performed over substantially the entire surface without moving the sensor housing 20, and for example, scanning is performed while reciprocating in the width direction. In comparison, the inspection process can be sped up.

The result of the pass / fail judgment is output and displayed on the monitor 30 by the result output unit 29, and the minute defect of the transparent film 1 moving at high speed is visually recognized by the operator.

[0060]

Second Embodiment FIGS. 5 to 7 illustrate a second embodiment of the present invention. The same or equivalent parts as those in the first embodiment will be described with the same reference numerals.

In the second embodiment, the first micro area optical sensor body for detecting with the same field of view width as the size of the foreign substance 8 used in the transparent film foreign substance inspection apparatus of the first embodiment is used. In addition to the diode 19a, similarly, a sensor as a second minute area optical sensor that directs the viewing direction at a predetermined angle α3 from the vertical direction to the irradiated portion on the other side surface 1b of the transparent film 1 A block 31 is provided.

In this sensor block 31, a photodiode 31a as a second minute area optical sensor main body is provided.
The viewing angle on the other side surface 1b of the transparent film 1 is set to 0.1 mm by a lens 31b provided in the small case 31c and provided on the front surface of the small case 31c.

Then, the sensor block 19 and the sensor block 31 form a pair and form the first embodiment.
As schematically shown in FIG. 3, a plurality of sensors are arranged in the vertical and horizontal directions at a predetermined interval on the sensor housing 20 so as to have a substantially lattice shape.

Then, these sensor blocks 19... And sensor block 31
0 sets and 120 sets in the film width direction for a total of 12000
The light source blocks 17 are arranged so as to face each of the light source blocks 17 with the transparent film 1 interposed therebetween.

The sensor housing 20 itself is fixed at α2 = 0.57 degrees with respect to the flow direction of the transparent film 1 so that the photodiode 1 is fixed.
The arrangement of 9a and the photodiodes 31a in the flow direction of the transparent film 1 is also inclined by α1 = 0.57 degrees with respect to the flow direction of the transparent film 1.

Further, in the transparent film foreign matter inspection apparatus according to the second embodiment, the light amount value is lower than the light amount when no ordinary foreign matter is stored in the storage unit 24 in the first embodiment. In addition to the pass / fail judgment reference value b1,
The pass / fail judgment reference value b2 is set in advance to a value darker than refracted light generated due to optical distortion in the presence of foreign matter, and a value brighter than the amount of light in the non-defective state.
Is stored.

Then, in addition to the quality judgment criterion b1 which is compared with the light quantity g1 detected by the first photodiode 19a by the quality judgment means 15, the quality judgment device of the quality judgment means 115 of the second embodiment is further added. 122, the second
The light amount g2 detected by the photodiode 31a is compared with a pass / fail judgment reference value b2 to determine the type of foreign matter.

Next, the operation of the second embodiment will be described with reference to the flowchart of FIG.

In the second embodiment, in Step 11,
When the inspection is started, the transparent film 1 is moved in the longitudinal direction by the rotational driving of the drive motor 27 provided on the transport line section 16 of the optical sensor detecting means 14. This movement is performed while the arrangement direction of the plurality of photodiodes 19a and the plurality of photodiodes 31a provided at predetermined intervals is inclined with respect to the transparent film 1 by a predetermined angle α2. Done.

For this reason, even if a set of a high-resolution photodiode 19a and a photodiode 31a having a small field width is provided at a predetermined interval from another adjacent pair as an optical sensor, the distance between the field of view of the photodiodes 19a and 19a can be increased. Along with the distance, the photodiodes 31a and 31a are also approached by the inclination α with respect to the relative movement direction, and the gap between the visual fields can be set to zero.

Therefore, as in the case of the number of the photodiodes 19a, 12,000 photodiodes 31a can be present within a predetermined width of 1200 mm of the transparent film 1.

An analog signal of the amount of light detected by the photodiodes 19a... And the photodiode 31a is sent to the A / D converter 23 to be converted into digital signals, respectively, and indicates the converted brightness. Signal value g
1, g2 (Step 12).

The pass / fail judgment device 122 compares the signal value g1 with the pass / fail judgment reference value b1 stored in the storage unit 124 (Step 13).

If no foreign matter 8 exists on the transparent film 1, the signal value g1 exceeds the pass / fail judgment reference value b1, and it is judged to be non-defective when g1> b1 (St).
ep14). Specifically, as shown in the upper left diagram in FIG. 7, the infrared light of the infrared light emitting diode 17a of the light source block 17 goes straight toward the photodiode 19a, and The light amount exceeding the pass / fail judgment reference value b1 as shown in the figure is detected by the photodiode 19a, and an output signal is output.

Further, on the transparent film 1, a foreign substance 8
Is present, the light quantity decreases and the pass / fail judgment reference value b
When the signal value g1 does not exceed 1, g1 <b1. Therefore, in the pass / fail determination device 122, g1
If <b1, it proceeds to the next Step 15. Specifically, in FIG. 7, the infrared light traveling straight from the infrared light emitting diode 17a of the light source block 17 toward the photodiode 19a is Foreign matter 8 or gel fisheye 108
The amount of light that has been blocked by the
And an output signal is output as shown in FIG.

At Step 15, the pass / fail judgment means 11
According to 5, the digital signal value g2 based on the light amount detected by the second photodiode 31a is a value darker than the refraction light generated due to optical distortion in the presence of the foreign matter, and the light amount in the non-defective state. The type of the foreign matter is determined by comparing with a pass / fail determination reference value b2 which is set to a value brighter than before.

If the digital signal value g2 is larger than the pass / fail judgment reference value b2, that is, g2 <b2, it is judged that the fish-eye is a gel fisheye (Step 16), and the digital signal value g2 is set to the pass / fail judgment reference value b2. G2> b which does not exceed
If it is 2, it is determined that the foreign substance 8 is present (St
ep17). Specifically, as shown in the middle left diagram in FIG. 7, the infrared light traveling straight from the infrared light emitting diode 17a of the light source block 17 toward the direction of the second photodiode 31a By the bubble section 7 of
When the scattered infrared light amount is detected by the photodiode 31a and an output signal is output as shown in the right middle diagram in FIG. 7, the converted digital signal value g2 also increases, and the pass / fail judgment reference value Beyond b1, it is determined that the foreign matter defect has the foreign matter 8 in the nucleus 6.

In addition, as shown in the lower left diagram in FIG. 7, the infrared light traveling straight from the infrared light emitting diode 17a of the light source block 17 toward the second photodiode 31a is not scattered but is If the light quantity detected by the photodiode 31a goes straight and does not increase as shown in the lower right part of FIG. 7, the converted digital signal value g2 does not increase and does not exceed the pass / fail judgment reference value b1. Is determined to be a foreign matter defect having a gel-like fish eye 108.

As described above, one side 1 on which the light source block 17 is disposed, with the transparent film 1 interposed therebetween.
a second photodiode 31a, which is provided on the other side 1b opposite to the side a and is oriented at a predetermined angle α3 from a vertical direction with respect to a portion to be illuminated so as to face the viewing direction, is provided on the illuminated portion of the transparent film 1. The optical distortion of is detected. Therefore, for example, even if there is a foreign matter defect, it is possible to determine whether the bubble part 7 or the like is formed around the foreign matter 8 or the gel-like fish eye 108.

Further, even if the first photodiode 19a and the second photodiode 31a are provided on the other side 1b of the transparent film 1, the arrangement direction is at a predetermined angle α1, with respect to the flow direction. Since the angle of view is inclined by α2 degrees, the visual field width is made close to and set to substantially 0, so that the inspection of the substantially entire surface of the transparent film 1 can be performed by checking a plurality of types of foreign substances, and in the second embodiment, the bubble section 7 around the bubble section 7. A foreign material 8 having
At the same time as distinguishing from the gel-like fish eye 108,
It is also possible to determine whether or not there is a foreign matter defect.
The inspection process can be sped up.

Although the first and second embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to the first and second embodiments, and the design is within the scope of the present invention. Modifications are included in the present invention.

In the first embodiment, a plurality of columns having a width r are combined and the sensor blocks 19 are arranged vertically and horizontally in a lattice shape. However, the present invention is not limited to this. The shape and quantity of the sensor blocks 19..., The type of optical sensor used, and the lens portion 17 b The presence / absence is not particularly limited, and the relative movement is performed while the arrangement direction of the plurality of micro area optical sensors arranged at predetermined intervals is tilted with respect to the inspection object. It is good if it is what is done.

In the first and second embodiments, the sensor housing 20 and the like are fixed, and
Although the transparent film 1 is moved along the longitudinal direction, the present invention is not particularly limited to this. For example, even if the sensor housing 20 is configured to be moved along the longitudinal direction of the transparent film 1, What is necessary is that the relative movement is performed while the arrangement direction of the minute area optical sensors is tilted with respect to the inspection object.

[0084]

As described above, according to the first aspect of the present invention, the plurality of micro regions arranged at predetermined intervals by the relative moving portion of the optical sensor detecting means. The relative movement is performed while the arrangement direction of the optical sensors is tilted with respect to the inspection object.

For this reason, even if a high-resolution micro-area optical sensor having a small visual field width of the optical sensor is provided at a predetermined interval,
The distance between the visual fields of the adjacent small area optical sensors is made closer to each other with an inclination to the relative movement direction. For example, by arranging a plurality of small area optical sensors of the size of the inspection object in the width direction / the field width of one small area sensor in the width direction of the inspection object, a gap between the field widths is reduced. Can be eliminated. Therefore, even if the resolution is improved, there is little possibility that the inspection will be missed, and it is possible to inspect foreign substances at high speed over the entire surface of the transparent film.

According to the second aspect of the present invention, a plurality of micro-area optical sensors of the optical sensor detecting means are arranged in a vertical and horizontal direction substantially in a lattice at predetermined intervals.
While the vertical and horizontal arrangement directions are inclined with respect to the direction of relative movement with respect to the inspection object, they are relatively moved by the relative moving unit.

For this reason, even if a high-resolution small area optical sensor having a small field width of the optical sensor is provided at a predetermined interval, the distance between the visual fields of the adjacent small area optical sensors is inclined with respect to the relative movement direction. , And arranged in the vertical direction, so that the number of micro-area optical sensors provided within a predetermined width can be increased.

And, according to the third aspect,
A housing in which the micro-area optical sensors are arranged at predetermined intervals is fixed at an angle with respect to the flow direction of the transport line unit, and the transparent film conveyed and moved by the transport line unit is substantially full width in the width direction. And inspect.

For this reason, even if the predetermined speed at which the transparent film passes opposite to the housing is given to the transparent film, each of the micro area sensors only inspects a predetermined micro area, and the Inspection can be performed over the entire surface, and the inspection process can be sped up.

According to the fourth aspect of the present invention, the illuminating means is provided on the other side of the illuminating means with the transparent film interposed therebetween, and is provided at a predetermined angle from a vertical direction with respect to a portion to be illuminated. The second minute area optical sensor that turns the direction,
Optical distortion of an irradiated portion of the transparent film is detected. For this reason, for example, it is possible to determine whether bubbles or the like are formed around the foreign matter.

Further, the first side of the transparent film
Even if the micro-area optical sensor and the second micro-area optical sensor are provided, the arrangement direction is tilted, so that the field of view is made close to and substantially zero by setting the field of view width close to substantially zero. Can be simultaneously performed while discriminating the types of a plurality of foreign substances, and the inspection process can be further speeded up.

Further, according to the present invention, the light amount detected by the second micro area optical sensor is compared with a reference value set in advance in the acceptability judging means, and the light amount detected by the second minute area optical sensor is used. A value that is darker than the refracted light generated by optical distortion in the state, and a value that is brighter than the amount of light in the non-defective state, a specific type of foreign matter, for example,
This has a practically useful effect of determining that the central nucleus is a gel fish eye.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional perspective view illustrating a configuration of a main part of a transparent film foreign matter inspection device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a transparent film foreign matter inspection device according to the first embodiment and illustrating a circuit configuration;

FIG. 3 is a schematic diagram illustrating a transparent film foreign matter inspection device according to the first embodiment, as viewed from above.

FIG. 4 is a flowchart illustrating a transparent film foreign matter inspection apparatus according to the first embodiment, and illustrating a control flow of pass / fail determination criteria;

FIG. 5 is a block diagram illustrating a transparent film foreign matter inspection device according to a second embodiment of the present invention and illustrating a circuit configuration.

FIG. 6 is a flowchart illustrating a transparent film foreign matter inspection apparatus according to a second embodiment and illustrating a control flow of pass / fail determination criteria;

FIG. 7 is a table illustrating an apparatus for inspecting a foreign substance of a transparent film according to a second embodiment, in which output signals for determining the type of the foreign substance among the criteria for quality determination are grouped for each micro-area optical sensor.

FIG. 8 is a perspective view of a conventional transparent film foreign matter inspection apparatus.

FIG. 9 is a conceptual diagram of a foreign substance.

FIG. 10 is a schematic view showing an image when a core is a gel in a conventional transparent film foreign matter inspection apparatus.

FIG. 11 is a schematic view showing an image when a core portion is a foreign substance in a conventional transparent film foreign substance inspection apparatus.

FIG. 12 is a conceptual diagram illustrating a configuration in which one-dimensional CCD cameras as optical sensors are arranged along a width direction of a transparent film.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Transparent film 6 Core part 7 Bubble part 8 Foreign substance 13 Illumination means 17 Light source block 17a Infrared diode main body 18 Light source housing 14 Optical sensor detecting means 19, 31 Sensor block (micro area optical sensor) 19a Photo diode (first micro area) Optical sensor body) 31a Photodiode (second minute area optical sensor body) 15,115 Pass / fail determination means 24,124 Storage unit 108 Gel fisheye

Claims (5)

[Claims] An optical sensor detecting means having a minute area optical sensor for detecting a foreign substance formed inside a transparent film to be inspected with substantially the same visual field width as the size of the foreign substance; From the measured value of the foreign matter detected by the sensor detection means,
The optical sensor detecting means is provided with a plurality of the micro area optical sensors arranged at predetermined intervals, and the direction of the arrangement is different from that of the inspection object. A foreign matter inspection device for a transparent film, comprising a relative moving portion inclined with respect to a relative moving direction. 2. An optical sensor detecting means having a minute area optical sensor for detecting a foreign substance formed inside a transparent film to be inspected with substantially the same visual field width as the size of the foreign substance; Quality judgment means for measuring the size of the foreign matter detected by the sensor detection means and judging the quality of the foreign matter from the measured dimensions, the light sensor detection means placing the micro area light sensor at a predetermined interval A foreign matter inspection apparatus for a transparent film, comprising a plurality of substantially lattice-shaped arrangements arranged in the vertical and horizontal directions, and a relative moving portion having the vertical and horizontal arrangement directions inclined with respect to the relative movement direction with respect to the inspection object. . 3. A transport line section for transporting and moving the transparent film along a longitudinal direction in the relative moving section, and a housing in which the micro-area optical sensors are arranged at predetermined intervals. 3. The apparatus for inspecting foreign matter in a transparent film according to claim 1, wherein the apparatus is fixed to be inclined with respect to the flow direction of the portion. 4. The micro-area optical sensor of the optical sensor detecting means includes an illuminating means for vertically irradiating light to one side surface of the transparent film, and an illuminating means facing the illuminating means on the other side surface of the transparent film. Position, and for the irradiated portion,
A first minute region light sensor for directing the viewing direction in the vertical direction, and a second minute region light for directing the viewing direction at a predetermined angle from the vertical direction with respect to the irradiated portion on the other side of the transparent film. The foreign matter inspection device for a transparent film according to any one of claims 1 to 3, further comprising a sensor. 5. The pass / fail judging means sets the light amount detected by the second minute area optical sensor to a value darker than refracted light generated by optical distortion in the presence of a foreign substance, and in a non-defective state. 5. The foreign film foreign matter inspection apparatus according to claim 4, wherein the type of foreign matter is determined by comparing with a pass / fail determination reference value set to a value brighter than the light amount.