JP2014232061A - Cloth inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cloth inspection device capable of increasing inspection accuracy by determining the existence of a foreign matter on the optical path of inspection light.SOLUTION: The cloth inspection device which irradiates inspection light on a spread cloth during movement from a light source and inspects the cloth by imaging transmitted light or reflected light using cameras 13, 19 includes: a calibration data storage part 21 for storing image data of inspection light at a normal time as calibration data; an acquisition data storage part 22 for imaging inspection light to be evaluated using a camera and storing image data of the inspection light as acquisition data; a primary difference data acquisition part 23 for obtaining a difference between the calibration data and the acquisition data to be defined as primary difference data; a smoothed data acquisition part 24 for smoothing the primary difference data to be defined as smoothed data; a secondary difference data acquisition part 25 for obtaining a difference between the primary difference data and the smoothed data to be defined as secondary difference data; and a foreign matter determination part 26 for determining that a light quantity is reduced due to a foreign matter when an integrated value of the secondary difference data is equal to or more than a predetermined value and outputting a determination result thereof.

Description

  The present invention relates to a cloth inspection apparatus that detects abnormalities such as dirt or tears on the surface or inside of an expanded cloth carried out from an ironing roller or the like in a cloth laundry factory or the like. The present invention relates to a cloth inspection apparatus that detects a decrease in the amount of inspection light due to light source deterioration.

  In cloth washing factories, after washing cloths such as sheets and bedding covers used in hospitals and hotels, etc., they are stretched by a stretcher in a semi-dry state, sent to an iron roller, ironed, and a folding machine It is folded and supplied again to hospitals and hotels. Therefore, when there is an abnormality such as dirt or tear on the surface or inside of the cloth during the washing process, it is necessary to remove the cloth from the above-described normal washing process line and separately process it.

  For this reason, the applicant of the present application has conventionally proposed, for example, the one described in Patent Document 1 as a cloth inspection device for detecting abnormalities such as dirt or tear on the surface or inside of the cloth. This cloth inspection apparatus inspects both the front and back surfaces of a cloth in combination with a folding machine arranged on the downstream side of the ironing roller. The cloth inspection apparatus moves the cloth on the first belt conveyor connected to the ironing roller. Take a picture of the upward surface (usually the back side is facing the iron roller, so the back side when the iron roller comes out) with the first camera from the top, then from the end of the first belt conveyor to the bottom With the second belt conveyor facing each other, turn the cloth hanging from the end of the first belt conveyor over, and then transport the cloth sandwiched between the first belt conveyor and the second belt conveyor, While handing over the second belt conveyor to the third belt conveyor, the other side (usually the surface) of the moving fabric is second Taken by the camera, from an image captured by these cameras, cloth for detecting the dirt, the dirt is detected on both surfaces of the textiles are excluded from the normal washing process line.

  In addition, the applicant of the present application has conventionally proposed, for example, the one described in Patent Document 2 as a cloth inspection device for detecting abnormalities such as dirt or tear on the surface or inside of the cloth. This cloth inspection device is integrated with the kneading and stretching device, and the first belt conveyor for loading and transporting cloths such as towels that have been washed and dried by workers, and the first belt conveyor. A second belt conveyor that conveys the fabric received from the second belt conveyor, and a third belt conveyor that conveys the fabric received from the second belt conveyor and delivers it to the folding machine. The cloth is stretched by speeding up the cloth and the cloth moving on the inspection table with the black part and the transparent part placed between the second belt conveyor and the third belt conveyor. Irradiate the inspection light from the upper and lower light sources, respectively, the image of the inspection light from the upper light source reflected by the cloth on the black part with the first camera from above, and the lower The image of the inspection light from the light source reflected on the cloth on the transparent part taken by the second camera from the bottom, and the inspection light directed from the upper light source to the transparent part by the reflecting mirror on the transparent part From the image taken with the second camera from the bottom of the light transmitted through the cloth, dirt and tears on both surfaces and inside of the cloth are detected, and the cloth where the dirt or tear is detected is stained. In the case of, it is sent to the washing process again and discarded if it is torn.

JP 2009-285109 A JP 2011-242330 A

  By the way, when the applicant of the present application further researched the conventional cloth inspection apparatus, in both of the above-described two kinds of cloth inspection apparatuses, the cloth moved by the belt conveyor is in a direction crossing the moving direction. The two-dimensional image of cloth is obtained by photographing with the extended one-dimensional digital camera as the first and second cameras, and the one-dimensional image is connected in the moving direction. Although the cloth is irradiated, it has been found that the inspection light source (fluorescent tube and LED) is deteriorated and foreign matters such as dust existing on the optical path cause the inspection accuracy to be lowered. For this reason, the applicant of the present application detects light source deterioration and light amount decrease due to dust by detecting a decrease in the maximum value of data (pixel value) photographed by the one-dimensional digital camera for the latter device, and dimmable illumination. Although we tried to adjust the brightness with the device, this method can be used for partial deterioration of the light source and for detecting foreign objects when using a reflector or a transparent part of the inspection table on the optical path as in the latter device. It has been found that there is an inconvenience that it is difficult to deal with.

The present invention solves the problems of the conventional cloth inspection apparatus as described above, and the first aspect of the cloth inspection apparatus of the present invention is:
The cloth spread while moving is irradiated with inspection light from a light source, the inspection light transmitted through the cloth or the inspection light reflected by the cloth is photographed with a camera, and the cloth is based on an image of the camera. In a cloth inspection device that inspects abnormalities such as dirt on the surface or inside of
A calibration data holding unit that captures normal inspection light with the camera and holds the image data of the inspection light as calibration data;
Taking the inspection light to be evaluated with the camera, an acquisition data holding unit that holds the image data of the inspection light as acquisition data,
A primary difference data acquisition unit that obtains a difference between the calibration data and the acquired data and sets the difference as primary difference data;
A smoothed data obtaining unit that smoothes the primary difference data to obtain smoothed data;
A secondary difference data acquisition unit that obtains a difference between the primary difference data and the smoothed data to obtain secondary difference data;
A foreign matter determination unit that determines that there is a decrease in the amount of light due to foreign matter when the integrated value of the secondary difference data is equal to or greater than a predetermined value, and outputs the determination result;
It is characterized by comprising.

Further, the second aspect of the cloth inspection device of the present invention is:
Irradiate inspection light from a light source onto the cloth that is being moved, and continuously inspect the inspection light transmitted through the cloth or the inspection light reflected by the cloth with a camera image. In the cloth inspection apparatus for inspecting abnormalities such as dirt on the surface or inside of the cloth,
A calibration data holding unit that captures normal inspection light with the camera and holds the image data of the inspection light as calibration data;
Taking the inspection light to be evaluated with the camera, an acquisition data holding unit that holds the image data of the inspection light as acquisition data,
A calibration data dividing unit that divides the calibration data into a plurality at an arbitrary width interval;
An acquired data dividing unit that divides the acquired data into a plurality at the same width interval as the calibration data;
A divided difference data acquisition unit that obtains a difference between average values of the image data of each section divided into a plurality of the calibration data and the acquired data, and sets the divided difference data;
A foreign matter / light source deterioration determination unit that determines that there is a light amount decrease due to foreign matter or light source deterioration when the maximum value of the divided difference data is equal to or greater than a predetermined value, and outputs the determination result;
It is characterized by comprising.

  In the first aspect of the cloth inspection apparatus of the present invention, the calibration data holding unit holds the image data of the camera of the inspection light at the time when the inspection light is normal as calibration data, and the acquired data holding unit Holds the image data of the camera of the inspection light at the time of evaluating the inspection light as acquisition data, and the primary difference data acquisition unit obtains the difference between the calibration data and the acquisition data to obtain the primary difference data And Since the primary difference data, which is the difference between the calibration data and the acquired data, may include both a light amount decrease due to foreign matters such as dust and a light amount decrease due to light source deterioration, the smoothed data acquisition is further performed here. The first difference data is smoothed by, for example, a low-pass filter to obtain smoothed data indicating a light amount decrease due to light source deterioration, and a second difference data acquisition unit calculates a difference between the first difference data and the smoothed data. The secondary difference data indicating the decrease in the amount of light due to foreign matter such as dust is obtained, and the foreign matter determination unit reduces the amount of light due to foreign matter such as dust when the integrated (cumulative) value of the secondary difference data exceeds a predetermined value. It is judged that there was, and the judgment result is output.

  Therefore, according to the first aspect of the cloth inspection apparatus of the present invention, since a case where a predetermined amount or more of foreign matter such as dust is present on the optical path of the inspection light is determined and output, the dust or the like is based on the determination result. The foreign matter can be removed to prevent a decrease in inspection accuracy, and the determination can be made even when a reflecting mirror or transmission plate is used on the optical path.

  In the second aspect of the cloth inspection apparatus of the present invention, the calibration data holding unit holds the image data of the inspection light camera at the time when the inspection light is normal as the calibration data, and the acquired data. The holding unit holds the image data of the camera of the inspection light at the time when the inspection light is evaluated as acquired data, and the calibration data dividing unit divides the calibration data into a plurality at arbitrary width intervals, and acquires the data divided Unit divides the acquired data into a plurality at the same width interval as the calibration data, and the divided difference data acquisition unit averages the image data of each section divided into the plurality of the calibration data and the acquired data The difference between them is obtained and used as divided difference data. Since this divided difference data may include both a light amount decrease due to foreign matter such as dust and a light amount decrease due to light source deterioration, the foreign object / light source deterioration determination unit determines that the maximum value of the divided difference data is predetermined. When the value is greater than or equal to the value, it is determined that there has been a decrease in light quantity due to foreign matter or light source deterioration, and the determination result is output.

  Therefore, according to the cloth inspection apparatus of the second aspect of the invention, it is determined whether or not there is a predetermined amount or more of foreign matter such as dust on the optical path of the inspection light and when the deterioration of the light source is proceeding more than a predetermined amount. Because it outputs, it can remove foreign substances such as dust and replace the light source based on the determination result, it can prevent a decrease in inspection accuracy, and even when using a reflector or transmission plate on the optical path, That determination can be made.

  In at least one of the cloth inspection devices according to the first and second aspects of the invention, the camera extends in a direction intersecting with the movement direction of the cloth and continuously photographs the inspection light. A one-dimensional digital camera may be used, and in this way, the cloth inspection can be continuously performed at a high speed and the cloth inspection apparatus can be configured at a low cost.

  The cloth inspection apparatus according to the second aspect of the invention may further include a cause determination unit that determines whether the cause of the decrease in light amount is a foreign object or a light source deterioration based on a peak pattern of the divided difference data. This is more preferable because foreign substances such as dust can be removed and the light source can be replaced according to the determination result.

It is a side view which shows the whole structure of one Example common to the 1st and 2nd aspect of the cloth inspection apparatus of this invention. It is explanatory drawing which expands and shows the A section of the cloth inspection apparatus of the said Example. (A) And (b) is the top view and side view which show the structure of the jump stand and cradle of the cloth inspection apparatus of the said Example. It is a block diagram which shows the foreign material determination process corresponding to the said 1st aspect of the cloth inspection apparatus of the said Example. (A) And (b) is explanatory drawing which shows the function of the foreign material determination process corresponding to the said 1st aspect. It is a block diagram which shows the foreign material and light source deterioration determination process corresponding to the said 2nd aspect of the cloth inspection apparatus of the said Example. (A), (b) and (c) is explanatory drawing which shows the function of the foreign material and light source degradation determination process corresponding to the said 2nd aspect. It is explanatory drawing which shows the example of light source deterioration.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view showing the overall configuration of one embodiment common to the first and second aspects of the cloth inspection apparatus of the present invention, and FIG. 2 is A of the cloth inspection apparatus of the above embodiment. FIG. 3 (a) and FIG. 3 (b) are a plan view and a side view showing the configuration of the jump stand and the cradle of the cloth inspection apparatus of the above embodiment. Reference numeral 1 denotes a normal ironing roller, 2 denotes a normal folding machine, and 3 denotes a cloth inspection apparatus of this embodiment.

  The cloth inspection apparatus 3 according to this embodiment is disposed between the ironing roller 1 and the folding machine 2 in a cloth washing factory or the like, and is carried out of the ironing roller 1 and conveyed to the folding machine 2 during the washing process. The cloth inspection apparatus 3 in this embodiment is a frame-like support frame 4 having side plates on both sides, and a support frame 4 for detecting abnormalities such as dirt or tear on the surface or inside of the cloth F. In FIG. 1, a delivery conveyor 5 which is provided on the left side portion and receives the spread fabric F carried out from the iron roller 1 and conveys it to the right in FIG. 1, and its conveyance direction with respect to the delivery conveyor 5. 1 is provided in the right side portion in FIG. 1 in the support frame 4 so as to be spaced apart from each other, and the spread fabric F fed from the delivery conveyor 5 is conveyed to the right in FIG. A receiving conveyor 6 that is handed over to a carry-in conveyor 2a that protrudes to the receiving conveyor 2 and a jumping base 7 and a receiving base 8 as jumping means for jumping the spread fabric F from the feeding conveyor 5 to the receiving conveyor 6. .

  Here, as shown in the plan view of FIG. 3A, each of the delivery conveyor 5 and the reception conveyor 6 has narrow conveyor belts 9 arranged side by side with a gap in the width direction. The jump stand 7 is shown in an enlarged view in FIG. 2 and as shown in the plan view and the side view of FIGS. 3A and 3B, the delivery side end of the delivery conveyor 5 (the right end in FIG. 1). Projected to Here, the jump stand 7 includes a comb-like portion 7 a that projects a large number of support portions from the gap of the conveyor belt 9 toward the receiving side end portion (left end portion in FIG. 1) of the receiving conveyor 6, and the extension of the delivery conveyor 5. It has a connecting portion 7b that extends in a horizontal direction orthogonal to the existing direction (a direction orthogonal to the paper surface in FIG. 1) and connects the tips of the support portions of the comb-like portion 7a.

  The cradle 8 is also shown in an enlarged view in FIG. 2 and, as shown in the plan view and side view of FIGS. 3A and 3B, the receiving side end of the receiving conveyor 6 (the left end in FIG. 1). Part). Here, the cradle 8 protrudes the support part from the gap of the conveyor belt 9 toward the delivery side end part (the right end part in FIG. 1) of the delivery conveyor 5, and the tips of the support parts are the same as the connection part 7b. It has the comb-shaped member connected with the connection part. A gap G is provided in the horizontal direction between the tip of the jump base 7 and the tip of the cradle 8, and a slight height difference is also provided in the vertical direction. It is located slightly higher than the tip of the base 8.

  Further, the cloth inspection apparatus 3 of this embodiment is arranged by being arranged near the sending conveyor 5 and the receiving conveyor 6 obliquely below the gap G, and the LED 10 as the transmission light source arranged obliquely above the gap G. A fluorescent tube 11 as a reflected light source, and a horizontal direction perpendicular to the extending direction of the delivery conveyor 5 and the receiving conveyor 6 attached to the side of the support frame 4 on the receiving conveyor 6 side via a bracket 12 (FIG. 1). Then, one or a plurality of one-dimensional digital video cameras (line sensors) 13 as cameras extending in a direction orthogonal to the paper surface, and a one-dimensional digital video arranged at the lower part of the central portion in the support frame 4. A reflecting mirror 14 extending in parallel with the camera 13, and the optical axis of the one-dimensional digital video camera 13 (light ) L1 is bent obliquely upward passes between and gap G of the fluorescent tube 11 by oblique upward reflecting surface of the reflecting mirror 14, are directed to LED10 as a transmission source.

  Furthermore, the cloth inspection apparatus 3 of this embodiment is arranged on the delivery conveyor 5 so as to extend in a horizontal direction perpendicular to the extension direction of the delivery conveyor 5 (in the direction perpendicular to the paper surface in FIG. 1). A blackboard 15 supported by a support member protruding from the gap of the conveyor belt 9, and a comb-like member 16 projecting upstream of the blackboard 15 in order to move the expanded fabric F on the blackboard 15; The fluorescent tube 17 serving as another reflected light source is disposed at an angle above the blackboard 15 and close to the delivery conveyor 5 and the reception conveyor 6, and the delivery conveyor is attached to the upper portion of the support frame 4 via a bracket 18. 5 and a one-dimensional digital video as another camera extending in a horizontal direction orthogonal to the extending direction of the receiving conveyor 6 (direction orthogonal to the paper surface in FIG. 1). A camera (line sensor) 19, which comprises a, the optical axis of the one-dimensional digital video camera 19 (an optical path) L2 passes between the fluorescent tube 17 is directed to the board 15.

  In the fabric inspection apparatus 3 of this embodiment having such a configuration, the jump stand 7 supports the expanded fabric F conveyed by the delivery conveyor 5 from below and is expanded from the tip. The cloth 8 is caused to jump, and the cradle 8 is expanded from the delivery conveyor 5 to the reception conveyor 6 by receiving the expanded cloth F jumped from the jump pedestal 7 and delivering it to the reception conveyor 6. The cloth F is caused to jump, and during that time, as shown in FIG. 2, the spread cloth F jumping through the gap G between the delivery conveyor 5 and the reception conveyor 6 is irradiated from the LED 10 as a transmission light source. Both the light transmitted through the cloth F and the light reflected from the cloth F irradiated from the fluorescent tube 11 as a reflection light source to the expanded cloth F jumping through the gap G Thus, the spread was cloth F is one-dimensional digital video camera 13 to shoot the image of the cloth F, and outputs a computer (not shown) constituting the conventional image processing apparatus.

  Therefore, according to the cloth inspection apparatus 3 of this embodiment, the image processing apparatus configured by the computer jumps the gap G between the sending conveyor 5 and the receiving conveyor 6 and spreads the cloth F. Both from the LED 10 and transmitted through the cloth F, and from the fluorescent tube 11 to the expanded cloth F jumping through the gap G and reflected from the cloth F. In the figure of the cloth F expanded based on the two-dimensional image, the image output from the one-dimensional digital video camera 13 that has photographed the cloth F is connected to the movement direction of the cloth F to form a two-dimensional image. Since the lower surface and the inside are inspected, it is possible to detect abnormalities such as stains and tears inside the fabric F as well as abnormalities such as stains on the surface of the same color as the fabric F with high inspection capability. It can be done, and cloth F Since inspection is not performed with transmitted light through a transparent table, the inspection capability is not reduced by dirt or scratches on the transparent table, so the high inspection capability can be maintained for a long time. .

  Further, according to the cloth inspection apparatus 3 of this embodiment, the cloth F spread on the delivery conveyor 5 is irradiated from the fluorescent tube 17 as a reflection light source and reflected from the surface of the cloth F by the light. A further one-dimensional digital video camera 19 is provided for photographing cloths and outputting an image to the computer. An image processing apparatus constituted by the computer outputs an image output from the one-dimensional digital video camera 19 to the computer. The cloth F is connected to the moving direction to form a two-dimensional image. Based on the two-dimensional image, the upper surface and the inside of the expanded cloth F are inspected. The image data (one-dimensional digital video camera 13) output by each of the two one-dimensional digital video cameras 13, 19, even if it is nearly transparent dirt that is transmitted by transmitted light, etc. Because it can detect based on 19 received light amount data of each pixel along the longitudinal direction of), it can exhibit higher examination capability.

  Moreover, according to the cloth inspection apparatus 3 of this embodiment, as a camera for inspection, a one-dimensional digital video camera 13 that extends in a direction crossing the moving direction of the cloth F and continuously shoots inspection light. , 19 can be used, and the cloth F can be inspected continuously at a high speed and the cloth inspection apparatus can be constructed at a low cost.

  By the way, in the cloth inspection apparatus 3 of this embodiment, in order to inspect the lower surface and the inside of the expanded cloth F, the reflecting mirror 14 is attached to the square pipe-shaped base frame 20 here. Since the reflecting surface is supported obliquely upward and supported by the support frame 4, foreign matter such as dust frequently falls and adheres to the reflecting surface of the reflecting mirror 14 as it is. The generated and accumulated foreign matter may affect the inspection accuracy. Similarly, there is a possibility that foreign matter such as dust adheres to the LED 10 and the fluorescent tubes 11 and 17 and the light amount of the inspection light is reduced. The light amount of the inspection light is also reduced due to deterioration of the LED 10 and the fluorescent tubes 11 and 17 themselves. May be reduced.

  Therefore, in the cloth inspection apparatus 3 of this embodiment, the computer further includes a calibration data holding unit 21 and an acquisition based on a program given in advance for the first aspect of the present invention, as shown in FIG. Each of the data holding unit 22, the primary difference data acquisition unit 23, the smoothed data acquisition unit 24, the secondary difference data acquisition unit 25, and the foreign matter determination unit 26 is configured as shown in FIGS. The function of performing the foreign matter determination process as shown in FIG.

  That is, the calibration data holding unit 21 captures the inspection light when the inspection light is normal, for example, immediately after replacement of the LED 10 and the fluorescent tubes 11 and 17 as new light sources with new ones. The acquired data holding unit 22 has photographed the inspection light at the time when the inspection light is evaluated, for example, after the cloth inspection apparatus 3 of this embodiment has been operated for a predetermined time. The image data of the one-dimensional digital video cameras 13 and 19 is held as acquired data, and the primary difference data acquisition unit 23 excludes the influence of sensitivity variations between the pixels of the one-dimensional digital video cameras 13 and 19. As shown in FIG. 5A, the difference between the calibration data held by the calibration data holding unit 21 and the acquired data held by the acquired data holding unit 22 is obtained to obtain the primary difference data. And (differential data A). When acquiring the calibration data and the acquired data, the cloth F is not present on the delivery conveyor 5 or the gap G, and the inspection light from the LED 10 is turned off with the fluorescent tube 11 turned off. 13, the inspection light from the fluorescent tube 11 is reflected by the one-dimensional digital video camera 13 while the LED 10 is turned off, and the inspection light from the fluorescent tube 17 is reflected from the blackboard 15. The light to be photographed is photographed by the one-dimensional digital video camera 19 to eliminate the influence of the difference in the state of the cloth F on the determination result.

  Since the primary difference data, which is the difference between the calibration data and the acquired data, may include both a light amount decrease due to foreign matters such as dust and a light amount decrease due to light source deterioration, the smoothed data acquisition unit 24 The primary difference data (difference data A) is smoothed by, for example, passing through a low-pass filter and removing fine light quantity changes due to foreign matters such as dust, and the like, to obtain smoothed data indicating a light quantity decrease due to light source deterioration. As shown in FIG. 5B, the secondary difference data acquisition unit 25 obtains a difference between the primary difference data and the smoothed data, and secondary difference data (difference) indicating a light amount decrease due to foreign matters such as dust. Data B), the foreign matter determination unit 26 determines that there is a decrease in the amount of light due to foreign matters such as dust when the integrated (cumulative) value of the secondary difference data is equal to or greater than a predetermined threshold, and the determination result is Example If output by the display device or the like.

  Therefore, according to the cloth inspection apparatus 3 of this embodiment based on the first aspect of the present invention, it is determined and output when there is a predetermined amount or more of foreign matter such as dust on the optical path of the inspection light. Foreign matter such as dust can be removed based on the determination result, and the inspection accuracy can be prevented from being lowered. Moreover, even when the reflecting mirror 14 is used on the optical path as in the one-dimensional digital video camera 13, the determination is made. It can be performed.

  Furthermore, in the cloth inspection apparatus 3 of this embodiment, the computer also acquires a calibration data holding unit 21 and an acquisition based on a program given in advance for the second aspect of the present invention, as shown in FIG. The data holding unit 22, the calibration data dividing unit 27, the acquired data dividing unit 28, the divided difference data acquiring unit 29, the foreign matter / light source deterioration determining unit 30, and the cause determining unit 31 are respectively configured, and FIG. It fulfills the function of performing foreign object / light source deterioration determination processing as shown in a), (b), and (c).

  That is, as in the first mode, the calibration data holding unit 21 images the inspection light when the inspection light is normal, for example, immediately after replacement of the LED 10 as the light source or the fluorescent tubes 11 and 17 with a new one. The image data of the one-dimensional digital video cameras 13 and 19 are held as calibration data, and the acquisition data holding unit 22 operates for a predetermined time of the cloth inspection apparatus 3 of this embodiment, for example, as in the first mode. The image data of the one-dimensional digital video cameras 13 and 19 that photographed the inspection light at the time of evaluation of the inspection light, such as later, are held as acquired data, and the calibration data dividing unit 27 is shown in FIG. As shown on the left side, the calibration data held by the calibration data holding unit 21 is divided into a plurality of intervals at an arbitrary width interval, and the acquired data dividing unit 28 acquires the acquired data as shown on the right side of FIG. Is divided into a plurality at the same width intervals as the calibration data, and the divided difference data acquisition unit 29, as shown in FIG. 7B, of the images of the sections divided into the plurality of the calibration data and the acquired data. The difference between the average values of the data is obtained and used as divided difference data (difference data C).

  Since this divided difference data may include both a light amount decrease due to foreign matter such as dust and a light amount decrease due to light source deterioration, the foreign object / light source deterioration determination unit 30 determines that the maximum value of the above divided difference data is When it becomes a predetermined threshold value or more, it is determined that there has been a decrease in the amount of light due to foreign matter or light source deterioration, and the cause determination unit 31 determines whether the cause of the decrease in light amount is a foreign matter or a light source deterioration based on the peak pattern of the divided difference data. The foreign matter / light source deterioration determination unit 30 and the cause determination unit 31 output the determination results by, for example, a display device or the like.

  Here, when the peak pattern of the divided difference data is, for example, the pattern 1 shown on the left side in FIG. 7C, the brightness of the end portion is decreased mainly due to deterioration of the fluorescent tubes 11 and 17. It is judged. For example, in the case of the pattern 2 shown at the center in FIG. 7C, it is determined that the LED 10 is partly deteriorated or partly reduced in brightness due to foreign matter. Are determined as anode spots, end bands, and the like. For example, in the case of the pattern 3 shown on the right side in FIG. 7C, it is determined that the amount of the inspection light is reduced overall due to the accumulation of foreign matters such as dust over a wide range.

  Therefore, according to the cloth inspection apparatus 3 of this embodiment based on the second aspect, when a predetermined amount or more of foreign matter such as dust is present on the optical path of the inspection light and when the light source deterioration has progressed by a predetermined amount or more. Accordingly, it is possible to remove foreign matters such as dust and replace the light source based on the determination result, and to prevent a decrease in inspection accuracy. Moreover, as in the case of the one-dimensional digital video camera 13, Even when the reflecting mirror 14 is used on the road, the determination can be made, and it is determined whether the cause of the decrease in the amount of light is a foreign object or a light source deterioration. Can be exchanged.

  Although the present invention has been described based on the illustrated examples, the present invention is not limited to the above-described examples, and can be appropriately changed within the scope of the claims. For example, in the above-described embodiments, the computer displays a normal image. In addition to the function of the processing apparatus, it has both the functions of the first and second embodiments of the present invention, but the function of the normal image processing apparatus and the first and second embodiments of the present invention are also included. The functions of the two forms may be provided by separate computers, or only one of the first form and the second form may be provided as necessary in addition to the functions of the normal image processing apparatus. Good.

  In addition, the cloth inspection apparatus according to the first and second embodiments of the present invention can be applied to the cloth inspection apparatus described in Patent Document 2, for example. In that case, the inspection light from the upper light source is used. The reflected light at the black part of the inspection table is photographed with the upper camera, the transmitted light at the transparent part of the inspection table is photographed with the lower camera, and the inspection light from the lower light source is transparent on the inspection table. The reflected light from the camera may be photographed with a camera below, and the deterioration of the light source and the presence of foreign matter on the optical path may be determined.

  Thus, according to the first aspect of the cloth inspection apparatus of the present invention, since a case where a predetermined amount or more of foreign matter such as dust is present on the optical path of the inspection light is determined and outputted, the dust such as dust based on the determination result is output. Foreign matter can be removed to prevent a reduction in inspection accuracy, and even when a reflecting mirror or transmission plate is used on the optical path, the determination can be made.

  Further, according to the cloth inspection apparatus of the second aspect of the invention, it is determined whether or not there is a predetermined amount or more of foreign matter such as dust on the optical path of the inspection light and when the deterioration of the light source is proceeding more than a predetermined amount. Because it outputs, it can remove foreign substances such as dust and replace the light source based on the determination result, it can prevent a decrease in inspection accuracy, and even when using a reflector or transmission plate on the optical path, That determination can be made.

DESCRIPTION OF SYMBOLS 1 Iron roller 2 Folding machine 2a Carry-in conveyor 3 Cloth inspection apparatus 4 Support frame 5 Sending conveyor 6 Receiving conveyor 7 Jump stand 7a Comb-like part 7b Connecting part 8 Receptacle 9 Conveyor belt 10 LED
DESCRIPTION OF SYMBOLS 11, 17 Fluorescent tube 12, 18 Bracket 13, 19 One-dimensional digital video camera 14 Reflector 15 Blackboard 16 Comb member 20 Base frame 21 Calibration data holding part 22 Acquisition data holding part 23 Primary difference data acquisition part 24 Smoothing data Acquisition unit 25 Secondary difference data acquisition unit 26 Foreign matter determination unit 27 Calibration data division unit 28 Acquisition data division unit 29 Division difference data acquisition unit 30 Foreign matter / light source deterioration determination unit 31 Cause determination unit L1, L2 Optical axis

Claims (3)

The cloth spread while moving is irradiated with inspection light from a light source, the inspection light transmitted through the cloth or the inspection light reflected by the cloth is photographed with a camera, and the cloth is based on an image of the camera. In a cloth inspection device that inspects abnormalities such as dirt on the surface or inside of
A calibration data holding unit that captures normal inspection light with the camera and holds the image data of the inspection light as calibration data;
Taking the inspection light to be evaluated with the camera, an acquisition data holding unit that holds the image data of the inspection light as acquisition data,
A primary difference data acquisition unit that obtains a difference between the calibration data and the acquired data and sets the difference as primary difference data;
A smoothed data obtaining unit that smoothes the primary difference data to obtain smoothed data;
A secondary difference data acquisition unit that obtains a difference between the primary difference data and the smoothed data to obtain secondary difference data;
A foreign matter determination unit that determines that there is a decrease in the amount of light due to foreign matter when the integrated value of the secondary difference data is equal to or greater than a predetermined value, and outputs the determination result;
A cloth inspection device characterized by comprising: The cloth spread while moving is irradiated with inspection light from a light source, the inspection light transmitted through the cloth or the inspection light reflected by the cloth is photographed with a camera, and the cloth is based on an image of the camera. In a cloth inspection device that inspects abnormalities such as dirt on the surface or inside of
A calibration data holding unit that captures normal inspection light with the camera and holds the image data of the inspection light as calibration data;
Taking the inspection light to be evaluated with the camera, an acquisition data holding unit that holds the image data of the inspection light as acquisition data,
A calibration data dividing unit that divides the calibration data into a plurality at an arbitrary width interval;
An acquired data dividing unit that divides the acquired data into a plurality at the same width interval as the calibration data;
A divided difference data acquisition unit that obtains a difference between average values of the image data of each section divided into a plurality of the calibration data and the acquired data, and sets the divided difference data;
A foreign matter / light source deterioration determination unit that determines that there is a light amount decrease due to foreign matter or light source deterioration when the maximum value of the divided difference data is equal to or greater than a predetermined value, and outputs the determination result;
A cloth inspection device characterized by comprising:   The cloth inspection apparatus according to claim 2, further comprising a cause determination unit that determines whether a cause of the light amount decrease is a foreign object or a light source deterioration based on a peak pattern of the divided difference data.