JPH09304182A - Grain color selector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect two wavelengths by a single sensor by correspondingly joining a light receiving element having high sensitivity to a wavelength in a visible light region and a light receiving element having high sensitivity to a wavelength in a near infrared region for integrally forming and using a CCD line sensor for at least one of them. SOLUTION: A CCD line sensor 22A is used as a light receiving element having high sensitivity in a visible region and an InGaAs array sensor 23A is used as a light receiving element having high sensitivity in a near infrared region. The sensor 22A is a one-dimensional image sensor comprising 256 CCD elements arranged in a lateral line, wherein chutes 5 corresponding to channels are less than CCD elements with respect to the 256 elements of the CCD line sensor. Thus twelve CCD elements are made to correspond to one chute 1, wherein the 256 elements are divided into 21 blocks for determining good and discolored grains for the respective CCD blocks comprising twelve elements.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grain color sorter for removing inorganic foreign matter such as discolored grains or glass fragments mixed in grains of rice, especially rice grains.

[0002]

2. Description of the Related Art Conventionally, inorganic grains such as discolored grains or glass fragments that are mixed into grains by irradiating falling grains with light rays in the visible light region and near-infrared region and using the transmitted / reflected light. Regarding the grain color sorter that removes dust,
1161.

The optical detecting section in this grain color sorter is provided with a light receiving sensor having a high sensitivity in the visible light range and a light receiving sensor having a high sensitivity in the near infrared range, and these two types of light receiving sensors are arranged. The following two types are proposed. That is, FIG.
11) and the plural lens types shown in FIG.
It is a dichroic type shown in (Fig. 2 of Japanese Patent Application No. 7-21161).

[0004]

In the case of the multi-lens type shown in FIG. 10, since the lens barrel is provided for each light receiving sensor, the entire optical detecting section becomes large, and each lens barrel (total of 4 locations) is large. The optical axis had to be adjusted, and there was a drawback that the adjustment was troublesome. On the other hand, the dichroic type shown in FIG. 11 includes a light-receiving sensor having high sensitivity in the visible light region and a light-receiving sensor having high sensitivity in the near infrared region in one lens barrel, so that the entire optical detection unit It becomes compact and the optical axes of the two front and rear lens barrels only have to be adjusted, and the optical axis adjustment is easier than that of the multiple lens type shown in FIG.

However, as a light receiving sensor having a high sensitivity in the visible light region, a multi-element CCD sensor (Charge
InGaAs (Indium-Gallium-) as a light receiving sensor having high sensitivity in the near infrared region by using a Coupled Device).
It has been found that it is difficult to adjust the optical axis of the dichroic type shown in FIG. 11 as well as the plural lens type shown in FIG. 10 when the arsenic sensor is used. This is shown in FIG. 12 and FIG.
3 and FIG.

FIG. 12 is a schematic view showing the end faces of a plurality of shoots (channels) 102 through which the grains flow down and the grains falling from each chute 102, which are monitored by a CCD sensor 101. CCD sensor 101 of this example
Is a so-called one-dimensional image sensor in which, for example, 256 elements are arranged in a horizontal row. And this CCD
The number of chutes 102 corresponding to the channel is 21 for 256 elements of the sensor, which is much smaller than that of CCD elements. For this reason, 12 CCD elements are associated with each chute (1 channel) and 25
The 6 elements are divided into 21 blocks, and 12 blocks are used to discriminate non-defective products and discolored particles for each block (channel). In this case, 12 ×
Since 21 = 252, four of the 256 elements are left over, but for the two elements at each end of the CCD sensor arranged in a horizontal row, the output is not handled and 252 elements are used. Output is valid.

Next, the optical axis adjustment of the CCD sensor 101 will be described. In FIG. 12, optical axis adjustment marks 103 are provided in a horizontal row at the grain detection position below the chute 102 so as to be parallel to the end surface of the chute 102. The optical axis adjustment mark 103 is coated with black dots corresponding to the boundaries of each chute. Then, the focus of the CCD sensor 101 via the condenser lens 104 is the optical axis adjustment mark 10.
Adjust it to fit 3. As a result, the CCD sensor 101 scans the optical axis adjustment mark 103 to output a detection waveform, and the output waveform determines whether or not the optical axis is accurate. That is, as shown in FIG. 13, the optical axis is accurate in the case where the valley of the waveform that becomes the boundary of each chute can be identified in correspondence with the element that should be the boundary position. If the object cannot be identified, the optical axis is not accurate. If the optical axis is not accurate, it is advisable to adjust the optical axis by adjusting the position of the CCD sensor 101 so that the waveform shown in FIG. 13 is detected.

In the case of the above-mentioned CCD sensor, the optical axis adjustment is relatively easy. On the other hand, the InGaAs sensor having a high sensitivity in the near infrared region is not in the CCD format, so the optical axis adjustment is difficult. is there. FIG. 12 and FIG.
4 describes the optical axis adjustment of the InGaAs sensor, the InGaAs sensor 105 corresponds to the number of the plurality of chutes 102, that is, the number of channels corresponding to 2
One element is arranged in a horizontal row. And InGa
Unlike the CCD sensor 101, the As sensor 105 cannot obtain signals from a plurality of elements at the same time, so the optical axis must be adjusted by a single signal intensity obtained from the elements. That is, the detection waveform shown in FIG. 14 is for monitoring the background corresponding to the InGaAs sensor 105, and in order to actually detect the signal intensity and adjust the optical axis, a sample such as a glass piece is made to flow and all the waveforms are detected. It was necessary to obtain a uniform signal from the element.

In view of the above problems, the present invention is provided with an optical detection unit for detecting two wavelengths of visible light region and near infrared region with one sensor, and facilitates optical axis adjustment and output balance adjustment of elements. A technical problem is to provide a grain color sorter.

[0010]

In order to solve the above-mentioned problems, the present invention provides a grain guiding means for guiding the grain along a predetermined grain flow path, and supplying the grain to the grain guiding means. A light receiving unit including a grain supply unit, an illumination unit that illuminates grains in a predetermined detection range when the grains fall from the grain flow path, and a light receiving sensor that receives a light amount from the illuminated grains. An optical detection means composed of a block and a background provided at a position facing the light receiving sensor with the falling trajectory of the grain interposed therebetween, and a removal signal is obtained by comparing an output signal of the optical detection means with an arbitrary threshold value. A grain color sorter provided with a control circuit for outputting and an ejector unit below the optical detection unit for removing defective grains or foreign substances by a removal signal of the control circuit, wherein the illumination unit is , Visible spectral energy distribution Using a light source of a single type or a plurality of types having a wavelength range and a near-infrared region, the light receiving block includes a filter having two pass bands, a condenser lens, and a light receiving sensor, and the light receiving sensor is in the visible light range. The first light receiving element having the high sensitivity to the wavelength and the second light receiving element having the high sensitivity to the wavelength of the near infrared region are integrally formed by joining them so as to correspond to each other arbitrarily, A technical measure was taken to use a CCD line sensor for at least one of the light receiving elements.

A plurality of CCD line sensor elements may be divided into one block, and the one block elements may be arranged in a horizontal row so as to correspond to each grain flow path.

As the first light receiving element, a silicon photodiode having high sensitivity in the visible light region can be used.

Further, as the second light receiving element, an InGaAs array sensor having a high sensitivity to wavelengths in the near infrared region or a germanium array sensor can be used.

[0014]

[Function] Defective grains such as discolored grains mixed in grains or inorganic foreign substances such as glass fragments fall from the grain flow path of the grain guiding means and are visible when they reach the detection range on the way. A first light receiving element (for example, CC, which is illuminated by a light source having a light region and a near infrared region and has high sensitivity to wavelengths in the visible light region)
The reflected / transmitted light is received by the D line sensor) and the second light receiving element (for example, InGaAs array sensor) having high sensitivity to the wavelength of the near infrared region. Then, whether it is a non-defective product or a discolored particle according to the detection signal of the first light receiving element, and whether it is a non-defective product or the same color as the non-defective product according to the detection signal of the second light receiving element or an inorganic foreign material such as a transparent glass piece. Whether or not there is is determined by the control circuit. Then, in the case of discolored particles and inorganic foreign matter, a removal signal is output to the ejector means corresponding to the grain flow path, and is ejected from the flow of non-defective products by jetting air.

The light receiving sensor is integrally formed by joining the first light receiving element and the second light receiving element so as to correspond to each other, and a CCD line sensor is provided on at least one of the first light receiving element and the second light receiving element. Since it is used, the optical axis of the first light receiving element and the optical axis of the second light receiving element behind it match,
If the optical axis of one CCD line sensor is adjusted, the optical axis of the other light-receiving element will be adjusted accordingly.

Further, a plurality of the elements of the CCD line sensor are divided into one block, and the elements of this one block are arranged in a horizontal row so as to correspond to each of the grain flow paths. The line sensor scans a plurality of grain flow paths to detect a rectangular waveform that distinguishes the grain flow path from the boundaries of each grain flow path, and the optical axis is accurate from this detected waveform. It has become possible to easily determine whether or not.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional view showing the overall configuration of a grain color sorter of the present invention. In FIG. 1, a raw material tank 2 is provided on an upper side on one side in a frame 1, a lower end of the raw material tank 2 is connected to a vibration supply gutter 3, and the raw material tank 2 is placed on a vibration generator 4 such as a vibrator. And the vibration supply gutter 3
Is connected to a plurality of chutes 5 provided at an angle. That is, the upper end of the chute 5 having a V-shaped or U-shaped cross section is provided in the vicinity of the gutter end of the vibration supply gutter 3, and the lower end thereof is faced between the pair of optical detection means 6. Below the chute 5, a cylindrical trough 7 for receiving grains falling from the lower end of the chute 5 is provided, and the lower end of the trough 7 is connected to a conveying means 8 for discharging a product. Also,
In order to remove inorganic foreign matter such as discolored grains or glass fragments from the grains passing through the detection range, the nozzle opening of the ejector valve 9 is provided near the detection range while falling from the lower end of the chute 5 into the gutter 7. Arrange. The ejector valve 9 is connected to an air compressor (not shown) via an air pipe 10. A defective product discharge port 11 is provided below the ejector valve 9, and a defective product discharge port 11 discharges defective products. Contact twelve. A control box 13 and an operation panel 14 are provided on the frame 1.

Next, one embodiment of the illumination means and the optical detection means 6 will be described with reference to FIG. The illumination means is arranged in the vicinity of the optical detection means 6 in order to irradiate the grains falling in the predetermined detection range F with light. For this illuminating means, a single type or a plurality of types of light sources having spectral energy distributions in the visible light region and the near infrared region are used. In this embodiment, the fluorescent tube 15 having the visible light region and the halogen having the near infrared region are used. A plurality of light bulbs 16 are provided so as to surround the detection range F.

The optical detecting means 6 comprises a light receiving sensor 17 for receiving the amount of light from the illuminated grain and a background 18 provided at a position facing the light receiving sensor 17 with a detection range F interposed therebetween. In this embodiment, the light receiving sensor 17 is provided in the light receiving block 20 in which the condenser lens 19 is inserted, and two sets of the light receiving blocks 20 are provided so that the back and abdomen of the grain can be simultaneously monitored. . The transparent glass plate indicated by reference numeral 24 is for preventing dust and the like from entering the optical detection means 6, 6, and a cleaning means (represented in the drawing) for reciprocally moving the cleaning body on the transparent glass plates 24, 24. No) may be provided.

A condenser lens 19 in the light receiving block 20.
A double peak filter 21 having a transmission characteristic in the visible light region and the near infrared region as shown in FIG.
Is provided. This transmission characteristic has two peak values, namely, a peak value in the visible light region near a wavelength of 450 nm and a peak value in the near infrared region near a wavelength of 1500 nm.

Next, the light receiving sensor 17 will be described with reference to FIG. The light receiving sensor 17 is integrally formed by joining the first light receiving element 22 having a high sensitivity in the visible light region and the second light receiving element 23 having a high sensitivity in the near infrared region so as to arbitrarily correspond to each other. At least one of the first light receiving element 22 and the second light receiving element 23 has a high resolution CC.
It is advisable to use a D line sensor. In this embodiment, a CCD line sensor (Charge Coupled Device) 22A is used for the first light receiving element 22 having high sensitivity in the visible light region,
InG in the second light receiving element 23 having high sensitivity in the near infrared region
It is preferable to use an aAs array sensor (Indium-Gallium-Arsenic) 23A.

In the case of this example, the CCD line sensor 2
2A is a so-called one-dimensional image sensor in which 256 CCD elements are arranged in a horizontal row.
For 256 elements of the D line sensor, the number of the chute 5 corresponding to the channel is, for example, 21 and C.
Much less than CD elements. Therefore, 12 CCD elements are associated with one chute (1 channel), 256 elements are divided into 21 blocks, and each CCD block (channel) with 12 elements is regarded as a good product. Determine the discolored particles. In this case,
Since 12 × 21 = 252, four of the 256 elements are left over, but for the two elements at the two ends of the CCD elements arranged in a horizontal line, the output is not handled and the output is 252. The output of the element of is valid.

The InGaAs array sensor 23A, which is joined to the CCD line sensor 22A so as to correspond arbitrarily, is, for example, a device in which 21 elements corresponding to the number of the chutes 5 are arrayed in a horizontal row.
Connected to the back of D block, CCD line sensor 22
A and the InGaAs array sensor 23A are integrally formed. Then, the transmitted / reflected light obtained by irradiating the object to be detected from the illumination means enters through the double peak filter 21 and responds to the wavelength near 450 nm shown in FIG. 3 by the CCD line sensor 22A. Long wavelengths in the near infrared pass through the CCD line sensor 22A and
It is incident on the array sensor 23A and responds to wavelengths near 1500 nm. The double peak filter 21 is preferably a narrow band filter so that the red light from the halogen bulb 16 does not enter the CCD line sensor 22A and the defective selection of colored particles does not occur. On one side of the light receiving sensor 17, a terminal 25 of the CCD line sensor 22A and a terminal 26 of the InGaAs array sensor 23A.
Are provided, and they are respectively input to the control circuit via an amplifier or the like. By the way, if the above-mentioned InGaAs array sensor 23A can be manufactured into a CCD element at a low cost by improving the technology, it can be formed into a CCD line sensor together with visible light.

Further, referring to FIG. 4, the light receiving sensor 1
The optical axis adjustment of No. 7 will be described. In FIG. 4, at the detection position F below the chute 5, the optical axis adjustment marks 27 are provided in a horizontal row so as to be parallel to the end surface of the chute 5. The optical axis adjustment mark 27 is coated with black dots corresponding to the boundaries 5A of each chute 5. Then, the focus of the CCD line sensor 22A, which is the first light receiving element, is adjusted via the condenser lens 19 so as to be aligned with the optical axis adjustment mark 27. As a result, the CCD line sensor 22A causes the optical axis adjustment mark 2
By scanning 7, the detected waveform is output (see FIG. 5),
Based on this output waveform, it is determined whether the optical axis is accurate. That is, as shown in FIG. 5, what can be discriminated by correlating the troughs of the waveforms at the boundaries of the shoots with the elements that should be the boundaries has an accurate optical axis, and the optical axes are shifted vertically and horizontally to discriminate the valleys of the waveforms. What cannot be done has an incorrect optical axis. If the optical axis is not accurate, the position of the light receiving sensor 17 may be adjusted so that the waveform as shown in FIG. 5 is detected. Further, since the InGaAs array sensor 23A which is the second light receiving element is formed integrally with the CCD line sensor 22A, there is no need to adjust the optical axis.

Next, correspondence between the detection signals of the light receiving elements 22 and 23 and the removal signal of the ejector valve 9 and the operation of the ejector valve 9 will be described with reference to FIGS. 6 and 7. FIG. 6 is a diagram showing reflected light amount characteristics of non-defective products (white rice), glass pieces, plastic pieces, and white stones.
FIG. 4 is a schematic diagram in which the detection signals of the respective light receiving sensors and the removal signals of the ejector valves are made to correspond to each other by monitoring the objects to be sorted by the light receiving block 20.

Light receiving element 22 having high sensitivity in the visible light region
6 and the light receiving element 23 having high sensitivity in the near-infrared region is used as shown in FIG.
This is for distinguishing the reflectance of white rice from the reflectance of glass pieces, plastic pieces, and white stone near 1600 nm.

Now, when the objects to be sorted reach the detection range F, they are illuminated by a light source having a visible light range and a near infrared range, and the CCD line sensor 22A and the near infrared range having a high sensitivity to the wavelength of the visible light range. In with high sensitivity to wavelength
The reflected / transmitted light is received by the GaAs array sensor 23A. At this time, for example, colored particles,
Assuming that glass pieces, plastic pieces, and white stones have arrived (see FIG. 7), the CCD line sensor 22A produces a detection signal for the colored particles due to the difference in color depending on the visible light range ((A) in FIG. 7). ). Further, the InGaAs array sensor 23A produces a detection signal for the plastic piece, the glass piece, and the white stone due to the difference in the amount of reflected light in the near infrared region ((B) of FIG. 7).

Then, as shown in FIG. 9, the detection signals of the CCD line sensor 22A and the InGaAs array sensor 23A are communicated to the amplifier 28 and the signal processing means 29, and are processed by the signal processing means 29 equipped with OR logic. Then, the removal signal is output ((C) of FIG. 7). The removal signal actuates the ejector valve 9 to eject compressed air from the nozzle port. In the example of FIG. 7, the sixth, eighth, eleventh, fourteenth and sixteenth ejector valves are operated, and the colored particles, the plastic pieces, the glass pieces and the white stones are blown off to perform selective removal. The blown foreign matter is transferred from the defective product discharge port 11 of FIG. 1 to the conveyance means 12 and discharged outside the machine.

In the above embodiment, the plurality of chutes 5 arranged in a slanted shape were mainly used as the grain guide means, but the conveyor belt 31 provided laterally on the pair of rollers 30 shown in FIG. Well, not only grains but also beans can be selectively removed.

Further, in the above-mentioned embodiments, the description has been made mainly on the use of the CCD line sensor having a high sensitivity to the wavelength of the visible light region and the InGaAs array sensor having a high sensitivity to the wavelength of the near infrared region as the light receiving element. , But is not limited to this, as a light receiving element having a high sensitivity in the near infrared region, a germanium array sensor is used,
A silicone photodiode can also be used as a light receiving element having high sensitivity in the visible light region.

[0031]

As described above, according to the present invention, the illuminating means uses a single or plural kinds of light sources whose spectral energy distribution has a visible light region and a near-infrared region, and two light receiving blocks are provided. The light receiving sensor includes a filter having a pass band, a condenser lens, and a light receiving sensor, and the light receiving sensor includes a first light receiving element having high sensitivity in a wavelength of a visible light region and a second light receiving element having high sensitivity in a wavelength of a near infrared region. And are integrally formed so as to correspond to each other arbitrarily, and a CCD line sensor is used for at least one of the first light receiving element and the second light receiving element. It became possible to detect with one sensor.

Further, a plurality of the elements of the CCD line sensor are divided into one block, and the elements of this one block are arranged in a horizontal row so as to correspond to each of the grain flow paths. The line sensor scans a plurality of grain flow paths to detect a rectangular waveform that distinguishes the grain flow path from the boundaries of each grain flow path, and the optical axis is accurate from this detected waveform. It has become possible to easily determine whether or not.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the overall configuration of a grain color sorter of the present invention.

FIG. 2 is an enlarged sectional view showing an illumination unit and an optical detection unit of the grain color sorter.

FIG. 3 is a diagram showing a transmission characteristic of a double peak filter.

FIG. 4 is a schematic view showing end faces of a plurality of chutes and grains falling from the chutes monitored by a light receiving sensor.

FIG. 5 is a detection waveform of a CCD line sensor.

FIG. 6 is a diagram showing reflected light amount characteristics of non-defective products (white rice), glass pieces, plastic pieces, and white stones.

FIG. 7 is a schematic diagram in which a detection signal of each light receiving sensor and a removal signal of an ejector valve are made to correspond to each other by monitoring the objects to be sorted by the light receiving block.

FIG. 8 is another embodiment of the grain guiding means.

FIG. 9 is a block diagram showing a control circuit of the present invention.

FIG. 10 is a schematic view showing an arrangement of conventional light receiving sensors.

FIG. 11 is a schematic view showing an arrangement of conventional light receiving sensors.

FIG. 12 is a schematic diagram of monitoring grains falling from each chute with a CCD sensor.

FIG. 13 is a detection waveform of a CCD sensor.

FIG. 14 is a detection waveform of an InGaAs sensor.

[Explanation of symbols]

 1 frame 2 raw material tank 3 vibration supply gutter 4 vibration generator 5 chute 6 optical detection means 7 gutter 8 transportation means 9 ejector valve 10 air tube 11 defective product outlet 12 transportation means 13 control box 14 operation panel 15 fluorescent tube 16 halogen Light bulb 17 Light receiving sensor 18 Background 19 Condenser lens 20 Light receiving block 21 Double peak filter 22 First light receiving element 22A CCD line sensor 23 Second light receiving element 23A InGaAs array sensor 24 Transparent glass plate 25 Terminal 26 terminal 27 Optical axis adjustment mark 28 amplifier 29 signal processing means 30 roller 31 conveyor belt

Claims (7)

[Claims] 1. A grain guide means for guiding a grain along a predetermined grain flow path, a grain supply means for supplying a grain to the grain guide means, and a grain from the grain flow path. When falling, illuminating means for illuminating the grain of a predetermined detection range, a light receiving block having a light receiving sensor for receiving the amount of light from the illuminated grain and the light receiving sensor across the falling trajectory of the grain An optical detection means composed of a background provided at an opposite position, a control circuit for outputting a removal signal by comparing an output signal of the optical detection means with an arbitrary threshold value, and a control circuit below the optical detection means. A grain color sorter provided with an ejector means for removing defective grains or foreign matter by a removal signal of the control circuit, wherein the illumination means has a spectral energy distribution in a visible light region and a near infrared region. Having a single or multiple light sources The light receiving block includes a filter having two pass bands, a condenser lens, and a light receiving sensor, and the light receiving sensor includes a first light receiving element having a high sensitivity to a wavelength in a visible light region and a wavelength in a near infrared region. And a second light receiving element having a high sensitivity are integrally formed by joining them so as to correspond arbitrarily, and a CCD line sensor is used for at least one of the first light receiving element and the second light receiving element. A grain color sorter that does. 2. A plurality of CCD line sensor elements are divided into one block, and the one block element is arranged in a horizontal row so as to correspond to each grain flow path. The described grain color sorter. 3. The grain color sorter according to claim 1, wherein the first light receiving element is a silicon photodiode having high sensitivity in a visible light region. 4. The grain color sorter according to claim 1, wherein the second light receiving element is an InGaAs array sensor having high sensitivity to wavelengths in the near infrared region. 5. The grain color sorter according to claim 1, wherein the second light receiving element uses a germanium array sensor having high sensitivity to wavelengths in the near infrared region. 6. The grain color sorter according to claim 1, 2, 3, 4 or 5, wherein the grain guide means is composed of a plurality of chutes arranged in an inclined shape. 7. The grain guide means comprises a conveyor belt provided laterally on a pair of rollers.
The described grain color sorter.