Optical sorter

Abstract

An optical sorter includes: a light source configured to irradiate light to a sorted object being conveyed on a conveyance path; an optical sensor configured to detect light associated with the sorted object and irradiated from the light source; a determination unit configured to determine a foreign matter and / or a defective product with respect to the sorted object based on a signal related to the light associated with the sorted object and acquired by the optical sensor; and an intermediate member disposed at a position between the light source and the conveyance path in an irradiation direction of the light from the light source to the sorted object, at a position not affecting detection of the light associated with the sorted object, and having a mark. The optical sensor is further configured to detect mark-associated light obtained by the mark via the mark.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an optical sorter. BACKGROUND

[0002] Conventionally, there is known an optical sorter that discriminates and removes foreign matter or defective product contained in an object to be sorted, using light information obtained by an optical sensor when light is irradiated from a light source to the object to be sorted (for example, Japanese Patent Application Publication No. 61-212734). The light information (for example, color gradation value) obtained by the optical sensor is compared with a threshold value, and based on the comparison result, it is determined whether the object to be sorted is a good product, or foreign matter or a defective product. The object to be sorted determined as foreign matter or a defective product is typically blown away by air blowing, whereby the object to be sorted is sorted into a good product, foreign matter, and a defective product.

[0003] However, in order to improve the sorting accuracy, there is room for improvement in the conventional optical sorter. SUMMARY

[0004] The present disclosure is achieved in order to solve the above-described problems, and for example, can be implemented as follows.

[0005] According to a first aspect of the present disclosure, there is provided an optical sorter. The optical sorter includes: a light source configured to irradiate light to an object to be sorted that is being conveyed on a conveyance path; an optical sensor configured to detect light that is irradiated from the light source and associated with the object to be sorted; a determination unit configured to determine foreign matter and / or a defective product with respect to the object to be sorted based on a signal related to the light associated with the object to be sorted and acquired by the optical sensor; and an intermediate member disposed at a position between the light source and the conveyance path in an irradiation direction of the light from the light source to the object to be sorted, at a position that does not affect detection of the light associated with the object to be sorted, and having a mark. The optical sensor is further configured to detect mark-associated light that is irradiated from the light source and obtained via the mark.

[0006] The light associated with the object to be sorted can be light reflected by the object to be sorted, i.e., reflected light, can be light that has passed through the object to be sorted, i.e., transmitted light, or can be both the reflected light and the transmitted light.

[0007] According to the optical sorter, various processes for improving the sorting accuracy can be performed based on the mark-associated light detected by the optical sensor. For example, the light amount of the light source can be detected based on the mark-associated light, and it can be determined whether the light amount is within an appropriate range. In addition, the intermediate member is arranged at a position that does not affect the light associated with the sorted object that is detected by the optical sensor, so the mark-associated light can be detected during the sorting operation of the optical sorter. Furthermore, the optical sensor can be shared between the detection of the light associated with the sorted object and the detection of the mark-associated light, so an additional optical sensor need not be provided only for the detection of the mark-associated light.

[0008] According to the second aspect of the present disclosure, in the first aspect, the optical sorter includes a detection unit configured to detect a state of the optical sensor based on a detection result of the mark-associated light. According to this aspect, various processes for suppressing deterioration of the sorting accuracy due to the state of the optical sensor can be performed based on the detected state of the optical sensor. For example, by reporting an abnormality related to the state of the optical sensor, it is possible to suppress the operation of the optical sorter in a state in which the sorting accuracy is deteriorated due to the state of the optical sensor. Alternatively, in a case where the deterioration of the sorting accuracy is grasped, the detected state of the optical sensor can be used as information for ascertaining the cause of the deterioration. The detected state of the optical sensor may, for example, include a state associated with the arrangement position of the optical sensor.

[0009] According to the third aspect of the present disclosure, in the second aspect, the state of the optical sensor detected by the detection unit includes at least one of the presence or absence of a positional deviation of the optical sensor, the amount of the positional deviation, the direction of the positional deviation, and the presence or absence of a focal point deviation of the optical sensor. According to this aspect, various processes for suppressing deterioration of the sorting accuracy due to the positional deviation or the focal point deviation of the optical sensor can be performed.

[0010] In a case where the state of the optical sensor detected by the detection unit includes the amount and the direction of the positional deviation, it is easy to perform a process or a measure for suppressing deterioration of the sorting accuracy due to the positional deviation. For example, the user can easily grasp how far and in which direction the arrangement position of the optical sensor is moved when performing an adjustment operation for eliminating the positional deviation.

[0011] In a case where the state of the optical sensor detected by the detection unit includes the presence or absence of the focal point deviation of the optical sensor (in other words, the state of not obtaining a focused state with respect to the sorted object), various processes for suppressing deterioration of the sorting accuracy due to the focal point deviation can be performed. For example, the optical sorter can perform a report to the user in a case where the focal point deviation is detected.

[0012] The optical sorter can also include a sorting section that ejects air toward a specific object to be sorted determined based on the determination result of the determination section to separate the specific object to be sorted from the conveyance path, and sorts foreign matter and / or defective products. In a case where the object to be sorted is conveyed in a first direction at a predetermined width in a second direction orthogonal to the first direction, the sorting section can be configured to eject air toward the specific object to be sorted from an appropriate position based on a predetermined correspondence relationship between the position of the light associated with the object to be sorted in the second direction and the position at which air should be ejected in the second direction. In this case, the optical sorter can further include a first correction section that corrects the predetermined correspondence relationship based on the amount of positional deviation of the optical sensor in the second direction.

[0013] In addition, the sorting section can be configured to eject air at a timing determined based on a predetermined delay ejection time. The delay ejection time is the time from the detection of the light associated with the specific object to be sorted to the ejection of air. In this case, the optical sorter can include a second correction section that corrects the predetermined delay ejection time based on the amount of positional deviation of the optical sensor in the first direction.

[0014] According to a fourth aspect of the present disclosure, in any one of the first to third aspects, the optical sorter includes a color correction section that performs color correction on the detection result of the light associated with the object to be sorted based on the detection result of the mark-associated light. According to this aspect, it is possible to adjust the color tone of the image represented by the detection result of the optical sensor. In a case where the mark is a monochrome mark, at least one of linear white balance correction and dark correction can be performed as the color correction. In a case where the mark is a color mark, non-linear color correction can be performed.

[0015] According to a fifth aspect of the present disclosure, in any one of the first to fourth aspects, the optical sorter includes a calibration section configured to be able to perform calibration based on the detection result of the mark-associated light. According to this aspect, it is possible to compensate for variations in the light amount of the light source in real time during sorting operation of the optical sorter.

[0016] According to a sixth aspect of the present disclosure, in the fifth aspect, the calibration includes adjusting the light amount of the light source based on the detection result of the mark-associated light. According to this aspect, it is possible to compensate for variations in the light amount of the light source without amplifying noise.

[0017] According to a seventh aspect of the present disclosure, in the fifth or sixth aspect, the calibration includes adjusting the gain with respect to the signal acquired by the optical sensor based on the detection result of the mark-associated light. According to this aspect, it is possible to compensate for variations in the light amount of the light source regardless of the light amount adjustment capability of the light source.

[0018] According to the 8th aspect of the present disclosure, in any one of the 1st to 7th aspects, the light source includes a 1st light source disposed on a 1st side with respect to the transfer path of the sorted objects, and a 2nd light source disposed on a 2nd side opposite to the 1st side. The optical sensor includes at least one of a 1st optical sensor disposed on the 1st side, and a 2nd optical sensor disposed on the 2nd side. The intermediate member is optically non-transmissive, and substantially prevents light from being transmitted from the transfer path side through the intermediate member to the optical sensor. According to this aspect, in a case where the optical sensor includes the 1st optical sensor, the intermediate member is disposed on the 1st side, so that light emitted from the 2nd light source disposed on the 2nd side does not transmit through the intermediate member and reach the 1st optical sensor disposed on the 1st side. Therefore, when the 1st optical sensor detects the marker-associated light emitted from the 1st light source and passing through the marker, light emitted from the 2nd light source along with the marker-associated light is not detected by the 1st optical sensor. Similarly, in a case where the optical sensor includes the 2nd optical sensor, the intermediate member is disposed on the 2nd side, so that light emitted from the 1st light source disposed on the 1st side does not transmit through the intermediate member and reach the 2nd optical sensor disposed on the 2nd side. Therefore, in a case where the amount of light from the light source is detected based on the marker-associated light, the amount of light can be more accurately detected. Furthermore, if the 8th aspect is combined with the 2nd aspect, the state of the optical sensor can be more accurately detected. Furthermore, in a case of being combined with the 5th aspect, calibration with higher precision can be performed based on the amount of light from the light source that is accurately detected. In addition, if the optical sensor includes both the 1st optical sensor and the 2nd optical sensor, the balance of the amount of light from the 1st light source and the amount of light from the 2nd light source can also be achieved.

[0019] According to the 9th aspect of the present disclosure, in any one of the 1st to 8th aspects, the marker includes at least one 1st unit region having a 1st color and having a constant size, and at least one 2nd unit region having a 2nd color different from the 1st color and having a constant size. The marker is configured such that the 1st unit region and the 2nd unit region are arranged one-dimensionally or two-dimensionally in a predetermined appearance pattern. The unit region is a region having a predetermined constant size and shape.

[0020] In a case where the 9th aspect is combined with the 2nd aspect, for example, based on whether the predetermined appearance pattern can be detected, or in which position the predetermined appearance pattern can be detected, the state of the optical sensor can be easily detected. In a case where the 1st unit region and the 2nd unit region are arranged one-dimensionally, based on the marker-associated light, the amount of positional deviation of the optical sensor in the arrangement direction of the 1st unit region and the 2nd unit region can be detected. In a case where the 1st unit region and the 2nd unit region are arranged two-dimensionally, based on which of a plurality of appearance patterns is detected and in which position the appearance pattern is detected, the amount and direction of positional deviation can be detected.

[0021] In a case where the conveyance path extends in the first direction and the sorted objects are conveyed in the first direction at a prescribed width in the second direction orthogonal to the first direction, the first unit region and the second unit region can also be arranged one-dimensionally in the second direction. Alternatively, the first unit region and the second unit region can also be arranged two-dimensionally in the first direction and the second direction. In this case, the appearance pattern of the first unit region and the second unit region in the second direction can also differ from each other at each arrangement position of the first unit region and the second unit region in the first direction. According to this configuration, based on the position and the kind of the detected appearance pattern, the amount of positional deviation and the direction of positional deviation can be easily detected.

[0022] According to a 10th aspect of the present disclosure, in the 9th aspect, the mark is a one-dimensional code or a two-dimensional code. In other words, the mark is a sign made based on a predetermined system in order to represent certain information. According to this aspect, in a case where the 10th aspect is combined with the 2nd aspect, based on whether or not the information represented by the code is read, the state of the optical sensor (for example, the presence or absence of positional deviation, the presence or absence of focal point deviation) can be easily detected. In addition, in a case where the mark is a two-dimensional code, based on what kind of information is read, the amount of positional deviation can be detected.

[0023] According to an 11th aspect of the present disclosure, an optical type sorting machine is provided. The optical type sorting machine, instead of the optical sensor of the 1st aspect, is provided with a 1st optical sensor configured to detect light associated with a sorted object, which is irradiated from a light source, and a 2nd optical sensor configured to detect mark-associated light obtained by the mark via the light irradiated from the light source. By this aspect, the same effect as the 1st aspect can also be obtained. Any one of the 2nd to 10th aspects can also be combined with the 11th aspect. In a case where the 2nd aspect is combined with the 11th aspect, the detection unit is configured to detect the state of the 2nd optical sensor.

[0024] According to a 12th aspect of the present disclosure, there is provided an optical sorter. The optical sorter includes: a light source configured to irradiate light to an object to be sorted that is being conveyed on a conveyance path; an optical sensor configured to detect light that is irradiated from the light source and is associated with the object to be sorted; a determination unit configured to determine a quality of the object to be sorted based on a signal related to the light associated with the object to be sorted and acquired by the optical sensor; and an intermediate member disposed at a position between the light source and the conveyance path in an irradiation direction of the light from the light source to the object to be sorted, and disposed at a position that does not affect detection of the light associated with the object to be sorted, and having a mark. The optical sensor is further configured to detect mark-associated light that is irradiated from the light source and is obtained via the mark. The mark includes a plurality of regions. The plurality of regions are respectively configured to provide at least one or more functions for ensuring determination performance of the determination unit based on the mark-associated light. According to the optical sorter, various processes for improving determination performance of the determination unit and further sorting accuracy can be implemented by each of the plurality of regions.

[0025] According to a 13th aspect of the present disclosure, in the 12th aspect, the at least one function includes at least one of a light amount detection function of the light source, a position deviation detection function of the optical sensor, a focus deviation detection function of the optical sensor, and a white balance confirmation function of the optical sensor.

[0026] According to a 14th aspect of the present disclosure, in the 13th aspect, the optical sensor includes a plurality of light-receiving elements arranged in a straight line. Such an optical sensor can be a linear sensor or a region sensor. At least a part of the plurality of regions includes a first region configured to provide the position deviation detection function of the optical sensor. The first region includes small regions that can be recognized by a difference in color. A width of the small regions in an arrangement direction of the plurality of light-receiving elements is uniquely set according to a position in a direction intersecting the arrangement direction. The direction intersecting the arrangement direction can also be a direction orthogonal to the arrangement direction. According to this aspect, the position deviation of the optical sensor can be easily detected based on the mark-associated light. Specifically, in a case where the optical sensor deviates in the direction intersecting the arrangement direction, the direction and the amount of the deviation can be grasped based on the width of the small regions detected by the optical sensor. Further, in a case where the optical sensor deviates in the arrangement direction, the direction and the amount of the deviation can be grasped based on positions of a start point and / or an end point of the small regions detected by the optical sensor. The 14th aspect can also be implemented independently of the 12th aspect. For example, as the mark, only the above-described small regions can be used alone.

[0027] According to a 15th aspect of the present disclosure, in the 13th or 14th aspect, at least a part of the plurality of regions includes a 2nd region configured to provide a focus deviation detection function. The 2nd region has a small region that can be recognized by a difference in color. According to this aspect, the focus deviation of the optical sensor can be easily detected. For example, the focus deviation of the optical sensor can be detected based on a detection condition of an edge of a boundary of the small region in the image data of the mark-associated light corresponding to the 2nd region. In this case, in a case where a sharp edge of a predetermined degree is detected, it can be determined that no focus deviation has occurred, and in a case where the sharp edge is not detected, it can be determined that focus deviation has occurred. Alternatively, the focus deviation of the optical sensor can be detected based on a detection condition of the small region in the image data of the mark-associated light corresponding to the 2nd region. In this case, for example, a small region having a small size (for example, width) is set in advance, and in a case where the small region is detected, it can be determined that no focus deviation has occurred, and in a case where the small region is not detected, it can be determined that focus deviation has occurred. Further, the small region can also be in the form of a line. For example, the 2nd region can have a 1st line and a 2nd line thinner than the 1st line. In this case, the 1st line and the 2nd line can be set to have a thickness such that, when the optical sensor is focused at the detection position of the object to be sorted, the 1st line can be detected by the optical sensor but the 2nd line cannot be detected, and when the optical sensor is focused at the position of the mark, both the 1st line and the 2nd line can be detected by the optical sensor. The 15th aspect can be implemented independently of the 12th aspect. For example, as the mark, only the 2nd region can be used alone.

[0028] According to one embodiment of the present disclosure, the optical sensor is a linear sensor or an area sensor having a plurality of light-receiving elements arranged in a straight line. The intermediate member is disposed at a position that does not overlap the transfer path when viewed in any direction orthogonal to the direction in which the plurality of light-receiving elements are arranged. The plurality of light-receiving elements include light-receiving elements that detect the mark-associated light but do not detect the light associated with the object to be sorted during transfer, and light-receiving elements that do not detect the light associated with the object to be sorted during transfer but detect the mark-associated light. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a schematic view showing a brief configuration of an optical sorting machine according to a first embodiment.

[0030] Figure 2 is a schematic view showing the positional relationship of the light source, the intermediate member, and the optical sensor.

[0031] Figure 3 is a cross-sectional view of the intermediate member.

[0032] Figure 4is a diagram showing an example of a mark that the intermediate member has.

[0033] Figure 5 is a diagram showing a mark of the second embodiment.

[0034] Figure 6 is a diagram showing examples of various marks. DETAILED DESCRIPTION

[0035] Figure 1 is a schematic diagram showing a brief structure of an optical sorter (hereinafter, simply referred to as a sorter) 10 as a first embodiment. In the present embodiment, the sorter 10 is used for sorting foreign matters (for example, small stones, mud, glass pieces, and the like) and defective products (for example, unripe grains, colored grains, and the like) from rice grains (more specifically, brown rice or white rice) as a sorted object 90. The sorted object 90 is not limited to brown rice or white rice, and can be any granular object. For example, the sorted object 90 can be paddy rice, wheat grains, beans (soybeans, chickpeas, kidney beans, and the like), resins (pellets and the like), rubber pieces, and the like.

[0036] As shown in Figure 1 , the sorter 10 has an optical detection section 20, a storage tank 71, a feeder 72, a chute 73, a good product discharge chute 74, a defective product discharge chute 75, a sorting section 76, and a controller 80. The controller 80 controls the entire operation of the sorter 10. The controller 80 also functions as a determination section 81, a detection section 82, a first correction section 83, a second correction section 84, a color correction section 85, and a calibration section 86. The functions of the controller 80 can be realized by a CPU executing a prescribed program, can be realized by a dedicated circuit, or can be realized by a combination thereof. Each function of the controller 80 can also be realized by one device. For example, each function of the controller 80 can be realized by one CPU. Alternatively, each function of the controller 80 can be distributed to at least two devices. Details of the functions of the controller 80 will be described later.

[0037] The accumulation tank 71 temporarily accumulates the sorted objects 90. The feeder 72 feeds the sorted objects 90 accumulated in the accumulation tank 71 to the chute 73, which is an example of a sorted object transfer unit. The sorted objects 90 fed to the chute 73 slide on the chute 73 toward the lower side and fall from the lower end of the chute 73. The chute 73 has a prescribed width that enables a plurality of sorted objects 90 to fall at the same time. In the following description, the direction in which the transfer path 95 (in other words, the falling track of the sorted objects 90) of the sorted objects 90 that have fallen from the chute 73 extends will be referred to as the first direction Dl. Further, the width direction of the chute 73 (in other words, the direction on the bottom surface of the chute 73 that is orthogonal to the falling direction of the sorted objects 90) will be referred to as the second direction D2. The second direction D2 is orthogonal to the first direction Dl.

[0038] The optical detection section 20 irradiates the sorted objects 90 that have fallen from the chute 73 with light and detects light associated with the sorted objects 90 (specifically, transmitted light that has transmitted through the sorted objects 90 and reflected light that has been reflected by the sorted objects 90). An output from the optical detection section 20, which is an analog signal that indicates the intensity of the detected light, is amplified with a prescribed gain by an AC / DC converter (omitted from the drawing) and is further converted to a digital signal. This digital signal (in other words, a gray scale value that corresponds to the analog signal) is input to the controller 80. The controller 80 determines, as a process of the determination section 81, whether the sorted objects 90 are good products (in other words, rice grains of relatively high quality) or foreign matter (in other words, not rice grains) or defective products (in other words, rice grains of relatively low quality) based on the input detection result of the light (in other words, the image). This determination is performed for each of the sorted objects 90. This determination can employ any known determination method. Typically, the determination is performed by comparing the gray scale value of the image data with a threshold value that is decided in advance.

[0039] The sorted objects 90 that are determined to be foreign matter or defective products are sorted by the sorting section 76. Specifically, the sorting section 76 is provided with an air jet 77 that jets air 78 toward the sorted objects 90. The sorted objects 90 that are determined to be foreign matter or defective products are blown away by the air 78, depart from the falling track (in other words, the transfer path 95) from the chute 73, and are introduced into the defective product discharge chute 75 (indicated as sorted objects 91 in Figure 1 ). On the other hand, the sorted objects 90 that are determined to be good products are not jetted with the air 78. Therefore, the sorted objects 90 that are determined to be good products are introduced into the good product discharge chute 74 (indicated as sorted objects 92 in Figure 1 ) without changing the falling track.

[0040] The details of the functions of the optical detection section 20 and the controller 80 will be described below. As described above, the optical detection section 20 irradiates the sorted objects 90 with light and detects light associated with the sorted objects 90. The controller 80 determines, as a process of the determination section 81, whether the sorted objects 90 are good products (in other words, rice grains of relatively high quality) or foreign matter (in other words, not rice grains) or defective products (in other words, rice grains of relatively low quality) based on the input detection result of the light (in other words, the image). Figure 1As shown, the optical detection section 20 includes a first light source 30a, a first optical sensor 40a, a second light source 30b, and a second optical sensor 40b. The first light source 30a and the first optical sensor 40a are disposed on one side (also referred to as the front side) with respect to the transfer path 95 of the sorted objects 90. The second light source 30b and the second optical sensor 40b are disposed on the other side (also referred to as the rear side) with respect to the transfer path 95 of the sorted objects 90. The "front side" can be described as an example of the "first side" in the claims, and the "rear side" can be described as an example of the "second side" in the claims. Conversely, the "front side" can be described as an example of the "second side" in the claims, and the "rear side" can be described as an example of the "first side" in the claims.

[0041] The first light source 30a irradiates light 31a toward the sorted object 90 being transferred on the transfer path 95 (in other words, falling from the chute 73). Similarly, the second light source 30b irradiates light 31b toward the sorted object 90 being transferred. The first light source 30a is a light source unit in which a plurality of light emitting elements 32a are mounted on a single substrate. In the present embodiment, LEDs are used as the light emitting elements 32a. Therefore, the light emitting elements 32a are also referred to as LEDs 32a. The plurality of LEDs 32a include an LED that emits red light, an LED that emits blue light, and an LED that emits green light. The second light source 30b has the same structure as the first light source 30a and includes a plurality of LEDs 32b.

[0042] In Figure 1 the present embodiment, the number of each of the first light source 30a and the second light source 30b is one, but at least one of the first light source 30a and the second light source 30b can be a plurality. For example, two first light sources 30a can be disposed on the upper side and the lower side with respect to the detection position on the transfer path 95, respectively. Similarly, two second light sources 30b can be disposed on the upper side and the lower side with respect to the detection position on the transfer path 95, respectively.

[0043] The first optical sensor 40a and the second optical sensor 40b detect light that is irradiated from the first light source 30a and the second light source 30b and is associated with the sorted object 90. Specifically, the first optical sensor 40a on the front side can detect light 31a that is irradiated from the first light source 30a on the front side and is reflected by the sorted object 90, and light 31b that is irradiated from the second light source 30b on the rear side and is transmitted through the sorted object 90. The second optical sensor 40b on the rear side can detect light 31b that is irradiated from the second light source 30b on the rear side and is reflected by the sorted object 90, and light 31a that is irradiated from the first light source 30a on the front side and is transmitted through the sorted object 90.

[0044] In the present embodiment, the first optical sensor 40a is a linear sensor having a plurality of light-receiving elements 41a arranged in a straight line. The first optical sensor 40a can also be an area sensor. The plurality of light-receiving elements 41a are arranged in the second direction D2 (in other words, the width direction of the chute 73). Thus, the first optical sensor 40a can simultaneously capture a plurality of sorted objects 90 conveyed over a prescribed width of the chute 73. In the present embodiment, the first optical sensor 40a is a color CCD sensor and can individually detect red light, green light, and blue light. The first optical sensor 40a can also be another type of sensor such as a color CMOS sensor. In the present embodiment, the second optical sensor 40b has the same structure as the first optical sensor 40a and has a plurality of light-receiving elements 41b arranged in the second direction D2. The first optical sensor 40a and the second optical sensor 40b can also have different structures from each other.

[0045] The optical detection unit 20 further includes transparent members 21a and 21b. The transparent member 21a separates the first light source 30a and the first optical sensor 40a from the conveyance path 95 on the front side. Thus, the first light source 30a and the first optical sensor 40a are isolated from the conveyance path 95, and dust flying from the conveyance path 95 can be prevented from adhering to the first light source 30a and the first optical sensor 40a. Similarly, the transparent member 21b separates the second light source 30b and the second optical sensor 40b from the conveyance path 95 on the rear side.

[0046] The optical detection unit 20 further includes intermediate members 50 on the front side and the rear side, respectively. The intermediate member 50 on the front side is disposed between the first light source 30a and the conveyance path 95 in the direction of irradiation of the light 31a from the first light source 30a toward the sorted object 90. The intermediate member 50 on the rear side is disposed between the second light source 30b and the conveyance path 95 in the direction of irradiation of the light 31b from the second light source 30b toward the sorted object 90.

[0047] Figure 2 is a schematic view showing the positional relationship in the second direction D2 of the first light source 30a and the second light source 30b, the intermediate member 50, the first optical sensor 40a, and the second optical sensor 40b. The positional relationship shown in the drawing is the same on the front side and the rear side, and thus, the front side will be mainly described below. As shown in Figure 2 On the front side, a plurality of (18 in the illustrated example) light-emitting elements 32a are arranged in the second direction D2 of the plurality of light-receiving elements 41a of the first optical sensor 40a.

[0048] Figure 2 “V1” shown in the drawing indicates the total field of view of the second direction D2 of the first optical sensor 40a. In addition,Figure 2 The "V2" shown indicates a raw material field, that is, a range in which the sorted object 90 can be imaged. The width of the raw material field V2 corresponds to the width of the chute 73 (in other words, the width of the transfer path 95). The plurality of light receiving elements 41a are arranged in a manner that extends outward of the raw material field V2 in the second direction D2. Thereby, a non-raw material field V3 of the first optical sensor 40a is ensured on both sides of the raw material field V2 in the second direction D2.

[0049] The intermediate member 50 is disposed in a region of the transparent member 21a that corresponds to the non-raw material field V3. In other words, the intermediate member 50 is disposed at a position that does not affect the detection of light associated with the sorted object 90 by the first optical sensor 40a. In other words, the position is a position that does not overlap the transfer path 95 when viewed in an arbitrary direction orthogonal to the second direction D2. In the present embodiment, the intermediate member 50 is disposed on both sides of the transfer path 95 in the second direction D2.

[0050] The intermediate member 50 on the front side reflects the light 31a irradiated from the first light source 30a on the front side. The light 31a reflected by the intermediate member 50 is detected by the first optical sensor 40a (more specifically, the light receiving elements 41a corresponding to the non-raw material field V3). The intermediate member 50 is located outward of the second direction D2 from the boundary between the raw material field V2 and the non-raw material field V3, and thus the reflected light at the intermediate member 50 is not detected by the light receiving elements 41a corresponding to the raw material field V2. In contrast, the light associated with the sorted object 90 is not detected by the light receiving elements 41a corresponding to the non-raw material field V3. Similarly, the intermediate member 50 on the rear side reflects the light 31b irradiated from the second light source 30b on the rear side. The light 31b reflected by the intermediate member 50 is detected by the second optical sensor 40b (more specifically, the light receiving elements 41b corresponding to the non-raw material field V3).

[0051] As is clear from the description, the first optical sensor 40a is shared in the detection of the light associated with the sorted object 90 and the detection of the light 31a reflected by the intermediate member 50. Similarly, the second optical sensor 40b is shared in the detection of the light associated with the sorted object 90 and the detection of the light 31b reflected by the intermediate member 50.

[0052] In the present embodiment, the intermediate member 50 is in the form of a sheet-shaped member that can be attached to the transparent members 21a, 21b. In other words, the intermediate member 50 is a sheet-shaped member having an adhesive on one face. Thus, the device structure of the sorting machine 10 can be simplified. Furthermore, the manufacturing is easy, and the manufacturing cost is inexpensive. The intermediate member 50 can be implemented in an arbitrary form. For example, the intermediate member 50 can also be a plate-shaped member. In this case, the intermediate member 50 can also be disposed so as to be separated from the transparent members 21a, 21b.

[0053] Figure 3 is a sectional view of the intermediate member 50. In Figure 3 the intermediate member 50 adhered to the rear side of the transparent member 21b is shown. As illustrated, the intermediate member 50 on the rear side has a two-layer structure. Specifically, the intermediate member 50 has a first layer 51 on the side of the conveyance path 95 and a second layer 52 on the side opposite to the conveyance path 95. The first layer 51 is optically non-transmissive. Thus, the first layer 51 of the intermediate member 50 on the rear side substantially prevents the light 31a from the first light source 30a on the front side from passing through the intermediate member 50 from the side of the conveyance path 95 to reach the second optical sensor 40b. Although not shown, the intermediate member 50 adhered to the front side of the transparent member 21a also has a first layer 51 on the side of the conveyance path 95 and optically non-transmissive, and a second layer 52 on the side opposite to the conveyance path 95. Thus, the first layer 51 of the intermediate member 50 on the front side substantially prevents the light 31b from the second light source 30b on the rear side from passing through the intermediate member 50 from the side of the conveyance path 95 to reach the first optical sensor 40a.

[0054] The second layer 52 is at least partially formed of a material having light reflectivity. The second layer 52 of the intermediate member 50 on the front side reflects the light 31a irradiated from the first light source 30a, and the second layer 52 of the intermediate member 50 on the rear side reflects the light 31b irradiated from the second light source 30b.

[0055] In the present embodiment, as Figure 3 illustrated, the intermediate member 50 is disposed on the side opposite to the conveyance path 95 with respect to the transparent members 21a, 21b. Thus, the intermediate member 50 is not affected by dust generated in association with the conveyance of the sorted objects 90. Also, the exposed surface of the first layer 51 (in other words, the surface on the side opposite to the second layer 52) becomes the adhering surface of the intermediate member 50 to the transparent members 21a, 21b, and the exposed surface of the second layer 52 (in other words, the reflecting surface of the light 31b) does not have an adhesive. Thus, there is no concern that the adhesive hinders the reflecting performance of the second layer 52. Note that the intermediate member 50 can also be disposed on the side of the conveyance path 95 with respect to the transparent members 21a, 21b. In this case, the reflecting surface of the second layer 52 also abuts against the transparent members 21a, 21b, and thus is not affected by dust.

[0056] The intermediate member 50 (more specifically, the second layer 52) has a mark 53 on a surface thereof (more specifically, a surface on the side opposite to the transfer path 95). Therefore, it can also be said that the light 31a reflected by the intermediate member 50 and detected by the first optical sensor 40a and the light 31b reflected by the intermediate member 50 and detected by the second optical sensor 40b are light obtained via the mark 53 (in other words, reflected light at the mark 53), respectively. Such light obtained via the mark 53 is also referred to as mark-associated light. The mark 53 can be printed on the surface of the second layer 52, for example.

[0057] Figure 4 FIG. 6 is a view showing one example of the mark 53. Figure 4 FIG. 7 is a view showing the mark 53 as viewed in a direction orthogonal to the first direction Dl and the second direction D2. In Figure 4 the example shown in FIG. 7, the mark 53 is composed of a plurality of unit areas UA. The unit areas UA have a constant size and shape decided in advance. In Figure 4 the example shown in FIG. 7, the size and shape of the unit areas UA are shown in the lower right. The unit areas UA are Figure 4 squares in the example shown, but can be any shape. The mark 53 includes first unit areas 54 having a first color and second unit areas 55 having a second color. In the present embodiment, the first color is black and the second color is white. The first unit areas 54 and the second unit areas 55 are configured to be arranged two-dimensionally in the first direction Dl and the second direction D2 in a predetermined pattern of occurrence.

[0058] In the present embodiment, as shown in Figure 4 FIG. 8, the pattern of occurrence of the first unit areas 54 and the second unit areas 55 in the second direction D2 differs at each arrangement position of the first unit areas 54 and the second unit areas 55 in the first direction Dl (indicated as positions P1 to P19 in Figure 4 FIG. 8).

[0059] According to the sorting machine 10 described above, various processes for improving the sorting accuracy can be implemented using the mark-associated light. The following describes such processes. First, the controller 80 is configured to detect the states of the first optical sensor 40a and the second optical sensor 40b based on the detection results of the mark-associated light as a process of the detection section 82. The state of the first optical sensor 40a on the front side is detected based on the mark-associated light obtained via the mark 53 of the intermediate member 50 pasted to the transparent member 21a on the front side. The state of the second optical sensor 40b on the rear side is detected based on the mark-associated light obtained via the mark 53 of the intermediate member 50 pasted to the transparent member 21b on the rear side.

[0060] The state of the first optical sensor 40a and the second optical sensor 40b detected by the detection section 82 includes a state associated with the set positions of the first optical sensor 40a and the second optical sensor 40b. The state associated with such set positions can include at least one of the presence or absence of a positional deviation of the first optical sensor 40a and the second optical sensor 40b, the amount of the positional deviation, the direction of the positional deviation, and the presence or absence of a focus deviation.

[0061] The presence or absence of the positional deviation, the amount of the positional deviation, and the direction can be detected, for example, as follows. As a specific example, in the case where the first optical sensor 40a is disposed at a normal position, it is assumed that the region on the line L1 is imaged by the first optical sensor 40a. In this case, when the appearing pattern detected on the basis of the mark-associated light is the appearing pattern of the arrangement position P10, it can be detected that the first optical sensor 40a is not deviated in the first direction D1. On the other hand, when the appearing pattern detected on the basis of the mark-associated light is the appearing pattern of the arrangement position P12, it is known that the first optical sensor 40a is deviated to the position of the line L2 in the first direction D1 (more specifically, the direction from the arrangement position P1 toward the arrangement position P19). The amount of the deviation at this time is an amount of about 2 times the size of the unit region UA (more accurately, a distance that is larger than the length of one side of the unit region UA and smaller than 2 times the length).

[0062] In addition, on the basis of which one of the plurality of light-receiving elements 41a (which are arranged in the second direction D2) of the first optical sensor 40a detects the appearing pattern of each of the arrangement positions P1 to P19, it is possible to detect how much and to which side the first optical sensor 40a is deviated in the second direction D2.

[0063] Each of the appearing patterns of the arrangement positions P1 to P19 can also be stored in the memory of the controller 80 at the time of manufacture of the handler 10. Furthermore, it is also possible to store, as the appearing pattern corresponding to the first optical sensor 40a and the second optical sensor 40b located at a normal position, the appearing pattern detected on the basis of the mark-associated light detected by the first optical sensor 40a and the second optical sensor 40b after the first optical sensor 40a and the second optical sensor 40b are installed at appropriate positions at the manufacturing stage of the handler 10 in the memory of the controller 80. Similarly, it is also possible to store, as the detection position corresponding to the first optical sensor 40a and the second optical sensor 40b located at a normal position, the position of the light-receiving element that detects the appearing pattern in the memory of the controller 80.

[0064] Further, the presence or absence of the focus deviation can be detected, for example, as follows. In one embodiment, first, the image data (RAW data) of the mark-associated light is binarized. In this binarization, the pixel value corresponding to the gray color due to the focus deviation is converted to the pixel value corresponding to the white color. Then, by pattern matching, it is determined whether or not the appearance pattern represented by the binarized image matches a certain one of the plurality of appearance patterns (in other words, the appearance patterns for the arrangement positions P1 to P19) stored in advance. In a case where the appearance pattern represented by the image obtained by the binarization does not match any of the appearance patterns stored in advance, it is detected that the focus deviation has occurred. In an alternative embodiment, in the image data of the mark-associated light, the focus deviation can also be detected based on whether or not a sharply edged portion of a predetermined degree is detected.

[0065] In the present embodiment, the intermediate member 50 is arranged on both sides of the transfer path 95 in the second direction D2, and thus even in a case where the first optical sensor 40a or the second optical sensor 40b is arranged slightly deviated on one side in the second direction D2 to such an extent that does not give an impact on the sorting accuracy and is arranged largely deviated on the other side to such an extent that gives an impact on the sorting accuracy, the positional deviation can be reliably detected.

[0066] In a case where the positional deviation or the focus deviation of the first optical sensor 40a or the second optical sensor 40b is detected by the detection section 82, the controller 80 can also report the detected content to the user via the reporting section 88. The reporting section 88 can also be in the form of a screen of an operation panel of the sorter 10, a speaker, a lamp, or the like. In other words, the reporting can be performed in the form of a display on the screen, a warning sound, a lamp lighting, or the like. According to this structure, the user can notice the abnormality of the position or the focusing state of the first optical sensor 40a or the second optical sensor 40b early, and thus perform an operation for eliminating the abnormality. As a result, the sorting operation of the sorter 10 is continued regardless of whether or not the abnormality occurs, and thus it is possible to suppress the deterioration of the sorting accuracy. In addition, in a case where the controller 80 is configured to report the direction and the amount of the positional deviation, the user can easily grasp that the setting position of the first optical sensor 40a or the second optical sensor 40b is to be moved in which direction and to which extent in order to eliminate the positional deviation when performing the adjustment operation for eliminating the positional deviation. It can also be that, in a case where the first optical sensor 40a and the second optical sensor 40b have an auto-focusing function, the focus deviation is automatically eliminated when the focus deviation is detected.

[0067] In the present embodiment, in a case where the positional deviation of the first optical sensor 40a or the second optical sensor 40b is detected, the controller 80 can further automatically perform a process for suppressing the deterioration of the sorting accuracy due to the positional deviation. This process is performed as a process of at least one of the first correction section 83 and the second correction section 84.

[0068] First, the processing of the first correction section 83 will be described. In the sorting section 76, in order to simultaneously sort a plurality of sorted objects 90 that are simultaneously conveyed across the width of the chute 73, a plurality of valves (not shown) that control the injection of the air 78 are arranged in the second direction D2. Then, each of the detection positions of the sorted objects 90 in the second direction D2 of the first optical sensor 40a and the second optical sensor 40b is assigned a certain valve. In other words, the correspondence relationship between the position of the light detected in association with the sorted object 90 in the second direction D2 (hereinafter, also referred to as the detection position) and the position in the second direction D2 at which the air 78 should be injected (hereinafter, also referred to as the injection position) is determined in advance. If it is determined that one sorted object 90 is a foreign object or a defective product, the air 78 is injected from the injection position corresponding to the detection position of the one sorted object 90.

[0069] The controller 80, as the processing of the first correction section 83, corrects the correspondence relationship between the detection position and the injection position based on the amount of the positional deviation of the first optical sensor 40a or the second optical sensor 40b in the second direction D2. More specifically, if the positional deviation of the first optical sensor 40a or the second optical sensor 40b occurs in the second direction D2, the detection position in the correspondence relationship between the detection position and the injection position deviates in the direction of the positional deviation by the amount of the positional deviation. Therefore, the correction is made so that the injection position corresponding to the detection position deviates in the direction opposite to the direction of the positional deviation by the amount of the positional deviation. Thus, the correspondence relationship returns to the original normal state. According to the first correction section 83, even if the position of the first optical sensor 40a or the second optical sensor 40b deviates in the second direction D2, the sorting accuracy can be automatically suppressed from deteriorating due to the positional deviation.

[0070] Next, the processing of the second correction section 84 will be described. In the first direction Dl, the position at which the track of the sorted object 90 is changed (hereinafter, also referred to as the track change position) by the air 78 from the injector 77 is located lower than the detection positions of the first optical sensor 40a and the second optical sensor 40b. Therefore, the sorting section 76 is configured to inject the air 78 toward a foreign object or a defective product at a timing at which a predetermined time is delayed after the foreign object or the defective product is detected by the first optical sensor 40a or the second optical sensor 40b. This time difference is also generally referred to as a delayed injection time. The delayed injection time is determined in advance. The delayed injection time can be determined in advance as a constant value, or can be determined in a manner that becomes variable based on an arbitrary parameter (for example, the kind of the sorted object 90, the measured falling speed of the sorted object 90, and the like).

[0071] The controller 80 corrects the above-described delay ejection time based on the amount of positional deviation of the first optical sensor 40a or the second optical sensor 40b in the first direction Dl as the processing of the second correction section 84. For example, in a case where the first optical sensor 40a or the second optical sensor 40b deviates downward from the normal position in the first direction Dl, the distance between the detection position at which the first optical sensor 40a or the second optical sensor 40b detects the sorted article 90 and the track change position becomes smaller than in a case where no positional deviation occurs. Therefore, the controller 80 shortens the delay ejection time in correspondence with the amount of deviation in the first direction Dl. On the contrary, in a case where the first optical sensor 40a or the second optical sensor 40b deviates upward from the normal position in the first direction Dl, the controller 80 lengthens the delay ejection time in correspondence with the amount of deviation in the first direction Dl.

[0072] The delay ejection time can also be corrected using a function in which the amount of positional deviation of the first optical sensor 40a or the second optical sensor 40b in the first direction Dl is a variable. This function can also be determined in advance through experiments and stored in the memory of the controller 80. Alternatively, it can also be calculated through physical calculation based on the distance between the normal detection position at which the first optical sensor 40a or the second optical sensor 40b detects the sorted article 90 and the track change position, the inclination angle of the chute 73, the conveyance speed of the sorted article 90 (these can be measured or determined in advance through experiments), the amount of positional deviation of the first optical sensor 40a or the second optical sensor 40b in the first direction Dl, and the like. According to the second correction section 84, even if the position of the first optical sensor 40a or the second optical sensor 40b deviates in the first direction Dl, it is possible to automatically suppress deterioration of the sorting accuracy due to the positional deviation.

[0073] In the present embodiment, the amount of positional deviation is detected on both sides of the conveyance path 95 in the second direction D2. Therefore, in a case where the detection amount on one side differs from the detection amount on the other side, the average of the detection amounts on both sides can also be used, for example, to perform the processing of the first correction section 83 and the second correction section 84.

[0074] The processing of the detection section 82, the first correction section 83, and the second correction section 84 described above can also be performed as initial adjustment at the time of manufacture or initial use of the sorting machine 10. Alternatively, these processes can also be performed at a prescribed timing at the time of use (in other words, at the time of sorting operation) of the sorting machine 10. There is a possibility that the set positions of the first optical sensor 40a and the second optical sensor 40b will deviate due to an impact or the like received during conveyance of the sorting machine 10, but in the latter case, such post-manufacture position deviation can also be appropriately dealt with. Furthermore, the processing of the first correction section 83 and the second correction section 84 can also be performed automatically when a position deviation is detected, or can also be performed by manual operation, or can also be performed when a position deviation is reported to have occurred and no user operation is made within a prescribed period.

[0075] In addition, in the present embodiment, the controller 80 is configured to perform, as the color correction section 85, color correction of the detection result of light associated with the sorted object 90 based on the detection result of the marker-associated light. Specifically, the controller 80 can perform dark correction based on the imaging result of the first unit region 54 of black. Specifically, a representative value (for example, an average value) of the color gradation values of the image data of the first unit region 54 of black can be utilized as a black level.

[0076] In addition, the controller 80 can perform white balance correction based on the imaging result of the second unit region 55 of white. For example, linear white balance correction can also be performed in such a manner that, in a case where an image is represented by 256 gradations, a representative value of the color gradation values of the image data of the first unit region 54 of black corresponds to a gradation value of 0, and a representative value of the color gradation values of the image data of the second unit region 55 of white corresponds to a gradation value of 255. Such color correction processing can also be performed, for example, at the start of the sorting operation of the sorting machine 10. According to the color correction section 85, it is possible to approach the light detection performance before replacement when the first optical sensor 40a and the second optical sensor 40b or the first light source 30a and the second light source 30b are replaced. This is particularly effective in a case where the model of the component before replacement becomes discontinued in production and a replacement is newly installed.

[0077] In addition, according to the sorting machine 10 described above, it is possible to detect the light amount of the first light source 30a and the second light source 30b based on the marker-associated light (more specifically, the imaging result of the second unit region 55). The intermediate member 50 having the marker 53 is disposed at a position that does not affect the detection of light associated with the sorted object 90, and thus it is possible to detect the light amount of the first light source 30a and the second light source 30b in real time during the sorting operation of the sorting machine 10. Furthermore, it is not necessary to provide an additional optical sensor for detecting the light amount of the first light source 30a and the second light source 30b.

[0078] The first layer 51 of the intermediate member 50 has optical non-transparency as described above. Therefore, when the mark-associated light is detected by the first optical sensor 40a on the front side, the light 31b from the second light source 30b on the back side is not detected by the first optical sensor 40a together with the light 31a from the first light source 30a on the front side. Therefore, the light amount of the first light source 30a can be accurately detected without being affected by the light 31b irradiated from the second light source 30b. Similarly, the light amount of the second light source 30b can be accurately detected without being affected by the light 31a irradiated from the first light source 30a. In other words, even if the light amount fluctuation occurs in only one of the first light source 30a and the second light source 30b, the light amount of the first light source 30a and the light amount of the second light source 30b can be accurately detected, respectively. The optical non-transparency of the first layer 51 also contributes to more accurate detection of the shape of the mark 53, and further contributes to more accurate detection of the states of the first optical sensor 40a and the second optical sensor 40b.

[0079] According to the sorter 10, on both sides of the transfer path 95 in the second direction D2, the light amounts of the first light source 30a and the second light source 30b can be detected using the intermediate member 50. Therefore, compared to the case where the light amounts are detected on only one side, it is easy to grasp the trend of the light amounts of the first light source 30a and the second light source 30b locally. For example, in the case where the light amount abnormality occurs on only one side in the second direction D2, it is easy to grasp the abnormality.

[0080] In the present embodiment, in the sorter 10, further in order to improve the sorting accuracy, calibration and reporting can be performed based on the light amounts of the first light source 30a and the second light source 30b detected using the mark-associated light. Hereinafter, the structure will be described. In the present embodiment, the calibration is a process of the calibration section 86 of the controller 80, which is repeatedly executed in the sorting operation of the sorter 10. Specifically, the calibration section 86 first acquires the light amounts of the first light source 30a and the second light source 30b acquired using the mark-associated light as described above. The light amounts are acquired for each RGB color component. In addition, the light amounts are acquired on one side and the other side in the second direction D2, respectively. The acquired light amounts can be statistical values (for example, average value, median value, or the like) of the detection results of the second unit regions 55 of white color corresponding to the detection results of the plurality of light receiving elements 41a or 41b other than the raw material field of view V3.

[0081] Next, the calibration section 86 determines whether the acquired light quantity is within the first range. The first range can also be set in advance for each RGB color component. The first range is a range bounded by a first threshold TH1 and a second threshold TH2, and a reference value of the ideal light quantity is included in the first range. For example, the first threshold TH1 can be set to a value of -30% with respect to the reference value, and the second threshold TH2 can also be set to a value of +30% with respect to the reference value.

[0082] As a result of the determination, when a color component whose light quantity deviates from the first range exists, the controller 80 reports the light quantity abnormality to the user via the reporting section 88. According to this configuration, the light quantity abnormality of the first light source 30a or the second light source 30b can be reported in real time during the sorting operation of the sorter 10. Therefore, the user can notice the light quantity abnormality of the first light source 30a or the second light source 30b early. As a result, the sorting operation of the sorter 10 continues regardless of whether the light source abnormality occurs, and thus it is possible to suppress deterioration of the sorting accuracy.

[0083] On the other hand, with respect to all the RGB color components, if the light quantity is within the first range, next, the calibration section 86 determines whether the acquired light quantity is within a second range. The second range can also be set in advance for each RGB color component. The second range is a range bounded by a third threshold TH3 (TH1 < TH3) and a fourth threshold TH4 (TH4 < TH2), and the reference value is included in the second range. Moreover, as a result of the determination, if the acquired light quantity is not within the second range, the calibration section 86 performs calibration. The calibration here is a process of adjusting the light quantity of the first light source 30a and the second light source 30b in accordance with the detected light quantity. Specifically, the calibration section 86 adjusts the light quantity of the corresponding light emitting element 32a, 32b on the basis of the detection result of the corresponding light receiving element 41a, 41b for each color component. Furthermore, in the present embodiment, the light quantity on both sides of the transfer path 95 in the second direction D2 is detected, and thus the light quantity of the light emitting element 32a, 32b located on one side in the second direction D2 can be adjusted on the basis of the light quantity detection result at the one side, and similarly, the light quantity of the light emitting element 32a, 32b located on the other side in the second direction D2 can be adjusted on the basis of the light quantity detection result at the other side. If calibration is performed by adjustment of the light quantity, it is possible to compensate for the variation in the light quantity of the first light source 30a and the second light source 30b without amplifying noise.

[0084] In the present embodiment, the controller 80 adjusts the light amount of the light emitting elements 32a, 32b by PWM control. More specifically, at the time of shipment of the sorting machine 10, the controller 80 is set to apply a voltage to the light emitting elements 32a, 32b with a duty ratio of 50%. Also, the calibration section 86 compensates for variations in the light amount of the light emitting elements 32a, 32b by increasing or decreasing the duty ratio. In other words, when the light amount of the light emitting elements 32a, 32b is greater than a reference value, the calibration section 86 decreases the duty ratio so that the light amount becomes the reference value, and when the light amount of the light emitting elements 32a, 32b is less than the reference value, the calibration section 86 increases the duty ratio so that the light amount becomes the reference value. By making the default duty ratio less than 100%, it is possible to cope with both cases where the light amount is greater than the reference value and where the light amount is less than the reference value. In addition, when the light amount does not reach the reference value even if the duty ratio is changed, the controller 80 reports this via the reporting section 88.

[0085] On the other hand, if the acquired light amount is in the second range, the calibration section 86 determines not to perform calibration. In other words, in a case where the variation in the light amount is small enough that calibration is not needed, the execution of calibration is prevented. According to this approach, it is possible to reduce the load on the controller 80.

[0086] According to the calibration section 86, even if a variation in the light amount of at least one of the first light source 30a and the second light source 30b occurs during the sorting operation of the sorting machine 10, it is possible to compensate for this variation in real time. Also, by the intermediate member 50 described above, it is possible to accurately detect the light amount of each of the first light source 30a and the second light source 30b, respectively, and thus the accuracy of calibration is also high. Furthermore, it is possible to perform calibration in such a way that the intensity of the signal acquired by the first optical sensor 40a and the intensity of the signal acquired by the second optical sensor 40b fall within the same reference range. Thus, the accuracy of the determination by the determination section 81 is improved.

[0087] In addition, according to the calibration section 86, if the degree of variation in the light amount of the first light source 30a and the second light source 30b is such that the accuracy of determination can be appropriately ensured by calibration, calibration is performed, and if the degree of variation is such that the accuracy of determination cannot be appropriately ensured, the light amount is reported as abnormal. Thus, it is possible to take appropriate measures depending on the degree of variation in the light amount.

[0088] In an alternative embodiment, if the detected light amount is in the first range, the calibration section 86 performs calibration. In other words, if the difference between the detected light amount and the reference value is such that the light amount is not reported as abnormal, calibration is performed even if this difference is very small. According to this approach, it is possible to more carefully compensate for variations in the light amount of the first light source 30a and the first optical sensor 40a.

[0089] In still another alternative embodiment, the calibration section 86 performs calibration by adjusting the gain with respect to the signal acquired by the light-receiving elements 41a, 41b corresponding to the raw material field of view V2, instead of adjusting the light amount of the light-emitting elements 32a, 32b. In other words, when the light amount of the light-emitting elements 32a, 32b is more than the reference value, the calibration section 86 reduces the gain by the amount of the excess, and when the light amount of the light-emitting elements 32a, 32b is less than the reference value, the calibration section 86 increases the gain by the amount of the deficiency. In this embodiment, the change in the gain is performed by changing the gain in the AC / DC converter, but in the case where the amplification circuit is built into the first optical sensor 40a and the second optical sensor 40b, the gain of the amplification circuit can also be changed. According to this method, the variation in the light amount of the first light source 30a and the second light source 30b can be compensated regardless of the light amount adjustment capability of the first light source 30a and the second light source 30b.

[0090] In still another alternative embodiment, the calibration section 86 performs calibration by combining the method of adjusting the light amount of the light-emitting elements 32a, 32b with the method of adjusting the gain. For example, the default duty ratio can be set to 100%. In this case, when the light amount of the light-emitting elements 32a, 32b is more than the reference value, the calibration section 86 reduces the duty ratio in such a manner that the light amount becomes the reference value, and when the light amount of the light-emitting elements 32a, 32b is less than the reference value, the calibration section 86 increases the gain by the amount of the deficiency. According to this method, when the light amount of the light-emitting elements 32a, 32b is within an appropriate range, the light amount can be sufficiently ensured. Alternatively, the default duty ratio can be set to less than 100% (for example, 90%) in advance, and when the light amount does not reach the reference value even if the duty ratio is increased to 100%, the gain is adjusted with respect to the light amount of the deficiency.

[0091] The calibration processing and the reporting processing described above can be performed at any timing. For example, these processing can be performed instead of in the sorting operation of the sorting machine 10, before the start of the operation of the sorting machine 10, or in addition to in the sorting operation of the sorting machine 10, before the start of the operation of the sorting machine 10. In addition, in the case where the sorting machine 10 is configured to be able to clean the transparent members 21a, 21b by a wiper and to temporarily interrupt the sorting processing to perform the cleaning, the calibration processing and the reporting processing can also be performed at the time of the cleaning.

[0092] In the sorter 10 described above, the size of the unit region UA of the mark 53 can also be set to be the same degree as the size of the field of view of each of the plurality of light receiving elements 41a, 41b. In this way, the positional deviation of the first optical sensor 40a and the second optical sensor 40b can be detected with high precision. Alternatively, the size of the unit region UA can also be set to be about half (for example, about 1.5 mm if 3 mm) of the smallest size of the sorted object 90 (for example, 3 mm if it is a grain thickness). In this way, only the positional deviation that has a large effect on the sorting precision can be detected. Alternatively, the size of the unit region UA can also be set to be the same degree or more than the size of the field of view of each of the plurality of light receiving elements 41a, 41b and about half or less of the smallest size of the sorted object 90.

[0093] In alternative embodiments, various marks can be used instead of the mark 53 illustrated. Figure 4 For example, the mark can also include other unit regions of any color other than white and black instead of at least one of the first unit region 54 of black and the second unit region 55 of white illustrated. Figure 4 For example, the mark can also include other unit regions of any color other than white and black instead of at least one of the first unit region 54 of black and the second unit region 55 of white illustrated. Figure 4 For example, the mark can also include other unit regions of any color other than white and black instead of at least one of the first unit region 54 of black and the second unit region 55 of white illustrated.The other unit regions can also include two or more unit regions of mutually different colors. In addition, the mark can also be a color mark having two or more colors other than white and black. For example, the mark can also have unit regions of white, black, red, green, blue, cyan, magenta, and yellow, respectively. In the case of using such a color mark, the color correction section 85 can also be configured to perform non-linear color correction in such a way that the respective gray scale values of the image of the mark approach the colors decided in advance. In addition, the unit regions of the same color or different colors can also be spaced apart from each other, or can also abut without a gap as in the example illustrated. Figure 5

[0094] In addition, the unit regions do not necessarily need to be arranged two-dimensionally, and can also be arranged one-dimensionally in the second direction D2 only. In this way, the amount of positional deviation in the second direction D2 can be detected.

[0095] In addition, a two-dimensional code can also be used as the mark. In this way, the same effects as in the above-described embodiments can be obtained. The two-dimensional code can also be a standardized publicly known code, and for example, can be a stacked type (PDF417, CODE49, etc.) or a matrix type (QR code (registered trademark), Data Matrix, VeriCode (registered trademark), etc.). Alternatively, the two-dimensional code can also be an independently developed code.

[0096] Alternatively, one-dimensional codes (e.g., barcodes) can also be used as markers. In this case, if the markers are arranged in a bar-like pattern in the second direction D2, the amount of positional deviation in the second direction D2 can be detected. When one-dimensional or two-dimensional codes are used as markers, the state of the optical sensor (e.g., presence or absence of positional deviation, presence or absence of focus deviation) can be easily detected based on whether the encoded information is read. Furthermore, when the marker is a two-dimensional code, the amount of positional deviation in the first direction D1 can be detected based on the information read.

[0097] The markings are not limited to the examples mentioned above and can be single or multiple marks of any shape. For example, the markings can also be "+", "-", "■", "▲", etc.

[0098] The second embodiment will now be described. The second embodiment differs from the first embodiment only in that it includes reference numeral 153 instead of reference numeral 53; however, the device structure of the sorting machine 10 in the second embodiment is the same as that in the first embodiment. (As...) Figure 6 As shown, the marker 153 includes a first region 154, a second region 155, and a third region 156. These regions 154 to 156 each provide at least one function for ensuring the determination performance of the determination unit 81 based on the marker-associated light. In this embodiment, regions 154 to 156 each provide different functions. Hereinafter, regions 154 to 156 will be described in detail.

[0099] Region 154 provides position offset detection functionality for optical sensors 40a and 40b. Region 154 includes a small black region 157. Region 157 has a trapezoidal shape with an upper base and a lower base parallel to the second direction D2. White left and right small regions 158 and 159 are located on either side of region 157 in the second direction D2. In other words, the boundaries of region 157 are identified by their different colors. The width W1 of region 157 in the second direction D2 is uniquely determined by its position in the first direction D1 (in other words, the direction orthogonal to the second direction D2) due to its trapezoidal shape.

[0100] If the mark correlation light based on the first region 154 is detected, it is possible to detect the presence or absence, direction, and amount of positional deviation of the optical sensors 40a, 40b. In the case where the first optical sensor 40a is disposed at a normal position, it is assumed that the middle linear region Al is imaged by the first optical sensor 40a, and a specific example will be described below. If the position of the first optical sensor 40a deviates to one side in the first direction Dl, and the upper linear region A2 is imaged by the first optical sensor 40a, the width Wl of the small region 157 detected by the first optical sensor 40a becomes larger in proportion to the amount of deviation as compared with the normal position (middle linear region Al). On the other hand, if the position of the first optical sensor 40a deviates to the other side in the first direction Dl, and the lower linear region A3 is imaged by the first optical sensor 40a, the width Wl of the small region 157 detected by the first optical sensor 40a becomes smaller in proportion to the amount of deviation as compared with the normal position (middle linear region Al). Therefore, it is possible to detect the direction and amount of positional deviation in the first direction Dl based on the width Wl.

[0101] In addition, the boundary of the small region 157 and the left small region 158 is orthogonal to the second direction D2 (in other words, parallel to the first direction Dl). Therefore, even if the position of the first optical sensor 40a deviates in the first direction Dl, the detection position of this boundary in the second direction D2 does not change. On the other hand, if the position of the first optical sensor 40a deviates in the second direction D2, the detection position of this boundary (in other words, the start point of the small region 157 in the second direction D2) changes in correspondence with the direction and amount of deviation. Therefore, it is possible to detect the direction and amount of deviation in the second direction D2 based on the detection position of this boundary.

[0102] Further, in an alternative embodiment in which the boundary between the small region 157 and the right small region 159 is orthogonal to the second direction D2, the direction and the amount of the deviation in the second direction D2 can be detected based on the detected position of the boundary between the small region 157 and the right small region 159 (in other words, the end point of the small region 157 in the second direction D2). Further, in an alternative embodiment in which the boundary between the small region 157 and the left small region 158 is not orthogonal to the second direction D2 and the boundary between the small region 157 and the right small region 159 is not orthogonal to the second direction D2, the direction and the amount of the deviation in the second direction D2 can be detected based on the detected positions of both the start point and the end point of the small region 157 in the second direction D2. Although detailed description is omitted, the position deviation detection function can also be provided by the same principle using other portions of the first region 154 (portions other than the small regions 157 to 159). Further, in another alternative embodiment, the width Wl of the small region 157 can also be set to be uniquely determined depending on the position in a direction crossing the second direction D2 (hereinafter, also referred to as a crossing direction).

[0103] The second region 155 provides a focus deviation detection function of the optical sensors 40a, 40b. This second region 155 is provided with a plurality of first lines 161 in white and a plurality of second lines 162 in white. The second lines 162 are each thinner than any of the plurality of first lines 161.

[0104] The optical sensors 40a, 40b are each initially set to be in focus at any position in the second direction D2 at the detected position of the sorted object 90 (in other words, the position on the transfer path 95). Further, with respect to the front-side mark 153, the thicknesses of the first lines 161 and the second lines 162 are set so that, when the first optical sensor 40a is in focus at the detected position of the sorted object 90, the first optical sensor 40a can detect the first lines 161 but cannot detect the second lines 162 due to blurring, and when the first optical sensor 40a is in focus at the position of the mark 153, the first optical sensor 40a can detect both the first lines 161 and the second lines 162. The same applies to the relationship between the rear-side mark 153 and the second optical sensor 40b.

[0105] If the mark-associated light based on such a second region 155 is detected, it can be determined that a focus deviation has occurred with respect to the detected position of the sorted object 90 both when both the first lines 161 and the second lines 162 are not detected and when both the first lines 161 and the second lines 162 are detected. The determination of whether the first lines 161 and the second lines 162 can be detected can be performed, for example, based on the signals acquired by the optical sensors 40a, 40b and by a binarization process using a threshold, or by an edge detection process.

[0106] The 3rd region 156 provides a white balance confirmation function. Specifically, the 3rd region 156 is a region of white, and the current white balance setting can be confirmed based on the gray scale value of the mark-associated light obtained based on the 3rd region 156. Further, if necessary, the white balance can be corrected in a manner such that the gray scale value of the mark-associated light obtained based on the 3rd region 156 becomes an arbitrary reference value (for example, a reference value of a gray scale value of 255). The 3rd region 156 is a region of white as a whole, and thus the white balance confirmation function can be provided without being affected by a positional deviation of the optical sensors 40a, 40b.

[0107] At least one of the regions 154 to 156 can also provide a light amount detection function of the light sources 30a, 30b. In other words, the light amount of the light sources 30a, 30b can be detected based on the mark-associated light obtained via at least one of the regions 154 to 156. In this case, the processing of the calibration section 86 can be performed in the same manner as in the 1st embodiment based on the detected light amount. In this case, the calibration section 86 can also perform light amount adjustment by the aperture of the lens of the optical sensors 40a, 40b. Alternatively, the calibration section 86 can detect that at least a part of the light emitting elements 32a, 32b has become in a state where it cannot be lit due to a failure, deterioration, or the like, as a light amount abnormality based on the detected light amount.

[0108] Figure 6 Examples of various marks that can be used instead of the mark 153 are shown. Examples 1 to 4 are examples of marks that can provide the positional deviation detection function and the white balance confirmation function, and examples 5 to 8 are examples of marks that can provide the focus deviation detection function in addition to the positional deviation detection function and the white balance confirmation function. In examples 5 to 8, the focus deviation detection function is added by the combination of the relatively thick line and the relatively thin line as described above. Examples 1 to 3, 5 to 8 are monochrome marks using only black and white, and example 4 is a color mark having a plurality of colors other than black and white. Among them, with respect to Figure 5 Examples 1 to 8 shown above, the color of the mark is not particularly limited, and an arbitrary number and kind of colors can be used in the mark. This is also the same in the mark 153 shown in Figure 5 above. In addition, the shape of the outer contour and the inside of the mark is not limited to the various examples shown in Figure 6 and ​ above, and can be arbitrarily set as long as at least a part of the above-described functions can be provided.

[0109] The above describes embodiments of the present disclosure, but the above-described embodiments are for easy understanding of the present disclosure and are not intended to limit the present disclosure. The present disclosure can be changed and improved without departing from the gist thereof, and the present disclosure includes equivalents thereof. Furthermore, any combination or omission of each structural element recited in the claims and the specification can be made within a range in which at least a part of the above-described problems can be solved or at least a part of the effects is exerted.

[0110] For example, the first light source 30a and the second light source 30b can also be constituted by any form of light emitting element instead of an LED. The light emitting element can also be, for example, a fluorescent lamp, EL, or the like. Furthermore, the sorter 10 can also be provided with a light source that irradiates near-infrared light instead of the first light sources 30a and 30b, or in addition to the first light sources 30a and 30b. In this case, an additional intermediate member having the same function as the intermediate member 50 can also be provided for the near-infrared light source, and calibration processing and reporting processing can also be performed with respect to the near-infrared light source. Furthermore, an additional optical sensor for detecting near-infrared light can also be provided. In this case, processing of the detection section 82, the first correction section 83, and the second correction section 84 can also be performed with respect to the additional optical sensor. Furthermore, the light source for the sorter 10 is not limited to the structure that emits visible light and near-infrared light as exemplified earlier, and can also be constituted so as to emit electromagnetic waves (in other words, light in a broad sense) of any wavelength. In this case, any form of sensor can also be employed in order to detect electromagnetic waves emitted from the light source, and furthermore, an intermediate member having the same function as the intermediate member 50 can also be provided with respect to at least one of the light source and the sensor.

[0111] In addition, the first layer 51 of the intermediate member 50 can also be omitted. Alternatively, the intermediate member 50 can also be provided with a single-layer region and a multi-layer region. In addition, at least a part of the detection section 82, the first correction section 83, the second correction section 84, the color correction section 85, and the calibration section 86 can also be omitted. Alternatively, at least a part of the above-described reporting processing can also be omitted.

[0112] Further, one of the first optical sensor 40a and the second optical sensor 40b can be omitted, or one of the first light source 30a and the second light source 30b can be omitted. Along with such omission, the light associated with the sorted object 90 can also be one of the reflected light and the transmitted light. Conversely, the number of light sources can also be any number of two or more on the front side, or any number of two or more on the back side. Similarly, the number of optical sensors can also be any number of two or more on the front side, or any number of two or more on the back side. The number of light sources and the number of optical sensors can be the same or different between the front side and the back side. Further, the total number of light sources on the front side and the back side and the total number of optical sensors on the front side and the back side can be the same or different.

[0113] Further, the number of the intermediate members 50 can be any number of one or more.

[0114] Further, the sorter 10 can also have an additional optical sensor for detecting the marker-associated light in addition to the first optical sensor 40a and the second optical sensor 40b. In this case, the first optical sensor 40a and the second optical sensor 40b are used only for detecting the light associated with the sorted object 90.

[0115] Explanation of Reference Signs

[0116] 10... optical sorter; 20... optical detection section; 21a, 21b... transparent member; 30a... first light source; 30b... second light source; 31a, 31b... light; 32a, 32b... light emitting element; 40a... first optical sensor; 40b... second optical sensor; 41a, 41b... light receiving element; 50... intermediate member; 51... first layer; 52... second layer; 53... mark; 54... first unit region; 55... second unit region; 71... storage box; 72... feeder; 73... chute; 74... good product discharge chute; 75... defective product discharge chute; 76... sorting section; 77... ejector; 78... air; 80... controller; 81... determination section; 82... detection section; 83... first correction section; 84... second correction section; 85... color correction section; 86... calibration section; 88... reporting section; 90, 91, 92... sorted object; 95... transfer path; 153... mark; 154... first region; 155... second region; 156... third region; 157... small region; 158... left small region; 159... right small region; 161... first line; 162... second line; D1... first direction; D2... second direction; V1... total field of view of first optical sensor and second optical sensor; V2... raw material field of view of first optical sensor and second optical sensor; V3... non-raw material field of view of first optical sensor and second optical sensor.

Claims

1. An optical sorting machine, characterized in that, have: A light source configured to illuminate the sorted items being transported along a transport path; An optical sensor configured to detect light that is irradiated from the light source and associated with the sorted object; The determination unit is configured to determine foreign objects and / or non-conforming items related to the sorted item based on a signal related to light associated with the sorted item and acquired by the optical sensor. as well as An intermediate component is positioned between the light source and the transport path in the direction of light illumination from the light source to the sorted object, and is positioned so as not to affect the detection of the light associated with the sorted object, and has a marking. The optical sensor is further configured to detect mark-associated light obtained from illumination by the light source and passing through the mark. The marker is configured to provide at least one function for ensuring the determination performance of the determination unit based on the marker-associated light.

2. The optical sorting machine according to claim 1, characterized in that, The device includes a detection unit configured to detect the state of the optical sensor based on the detection result of the marker-associated light.

3. The optical sorting machine according to claim 1 or 2, characterized in that, It includes a calibration unit configured to perform calibration based on the detection results of the marker-associated light.

4. The optical sorting machine according to claim 1 or 2, characterized in that, The light source has the following features: A first light source, the first light source being disposed on a first side of the transport path relative to the sorted items; and A second light source, wherein the second light source is disposed on a second side opposite to the first side. The optical sensor includes at least one of a first optical sensor disposed on the first side and a second optical sensor disposed on the second side. The intermediate component is light-impermeable, which substantially prevents light from passing through the intermediate component from the transfer path side to reach the optical sensor.

5. The optical sorting machine according to claim 1 or 2, characterized in that, The mark includes at least one first unit region having a first color and a constant size, and at least one second unit region having a second color different from the first color and the constant size. The markings are configured such that the first unit region and the second unit region are arranged in a predetermined one-dimensional or two-dimensional pattern.

6. An optical sorting machine, characterized in that, have: A light source configured to illuminate the sorted items being transported along a transport path; A first optical sensor, configured to detect light that is irradiated from the light source and associated with the sorted object; The determination unit is configured to determine foreign objects and / or non-conforming items related to the sorted item based on a signal related to light associated with the sorted item and acquired by the optical sensor. An intermediate component is disposed at a position between the light source and the transfer path in the direction of light illumination from the light source to the sorted object, and is disposed at a position that does not affect the detection of the light associated with the sorted object, and has a marking. as well as A second optical sensor is configured to detect mark-related light obtained from illumination by the light source and passing through the mark. The optical sorting machine satisfies at least one of the following conditions: The marker is configured to provide at least one function for ensuring the determination performance of the determination unit based on the marker-associated light; The device includes a detection unit configured to detect the state of the optical sensor based on the detection result of the marker-associated light. It includes a calibration unit configured to perform calibration based on the detection results of the marker-associated light.

7. An optical sorting machine, characterized in that, have: A light source configured to illuminate the sorted items being transported along a transport path; An optical sensor configured to detect light that is irradiated from the light source and associated with the sorted object; The determination unit is configured to determine the quality of the sorted item based on a signal related to light associated with the sorted item and acquired by the optical sensor. as well as An intermediate component is positioned between the light source and the transport path in the direction of light illumination from the light source to the sorted object, and is positioned so as not to affect the detection of the light associated with the sorted object, and has a marking. The optical sensor is further configured to detect mark-associated light obtained from illumination by the light source and passing through the mark. The marker has multiple regions. The plurality of regions are each configured to provide at least one function for ensuring the determination performance of the determination unit based on the marker-associated light.

8. The optical sorting machine according to any one of claims 1, 2, 6, and 7, characterized in that, The at least one function includes at least one of the following: light quantity detection function of the light source, position deviation detection function of the optical sensor, focus deviation detection function of the optical sensor, and white balance confirmation function of the optical sensor.

9. An optical sorting machine, characterized in that, have: A light source configured to illuminate the sorted items being transported along a transport path; An optical sensor configured to detect light that is irradiated from the light source and associated with the sorted object; The determination unit is configured to determine foreign objects and / or non-conforming items related to the sorted item based on a signal related to light associated with the sorted item and acquired by the optical sensor. as well as An intermediate component having a mark that is illuminated by the light source. The optical sensor is configured to detect the marker-associated light obtained via the marker. The optical sorting machine includes a detection unit configured to detect the state of the optical sensor based on the detection result of the marker-associated light. The state of the optical sensor detected by the detection unit includes at least one of the following: presence or absence of positional deviation of the optical sensor, amount of positional deviation, direction of positional deviation, and presence or absence of focal deviation of the optical sensor.

10. An optical sorting machine, characterized in that, have: A light source configured to illuminate the sorted items being transported along a transport path; A first optical sensor, configured to detect light that is irradiated from the light source and associated with the sorted object; The determination unit is configured to determine foreign objects and / or non-conforming items related to the sorted item based on a signal related to light associated with the sorted item and acquired by the optical sensor. An intermediate component having a mark that is illuminated by the light source; A second optical sensor is configured to detect mark-related light obtained via the mark; as well as The detection unit is configured to detect the state of the first optical sensor based on the detection result of the marker-correlated light. The state of the first optical sensor detected by the detection unit includes at least one of the following: presence or absence of positional deviation of the first optical sensor, amount of positional deviation, direction of positional deviation, and presence or absence of focal deviation of the first optical sensor.

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