JPH0246275B2 - KOKURUITONOSHIKISAISENBETSUKI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color sorting machine for grains, etc.

[Conventional technology]

A color sorting machine is generally known that compares the brightness of reflected light from an object to be sorted with the brightness of reflected light from the background and excludes those whose brightness exceeds an allowable range. For example, as shown in FIG. 3, light from a light source 3 is irradiated onto grains 2 sent out from a chute 1. This light is applied to the grain 2 and the background 4,
The reflected light is detected via a lens 5, a filter 6, and a photodiode 7. The detected reflected light is converted into an electrical signal, amplified by an amplifier 8, and then compared with a reference value by a comparator 9. Items to be sorted whose difference from the reference value was outside the allowable range were removed and sorted by the air gun 9'.

By the way, as shown in Fig. 4, in a color sorter that sorts grains by brightness (color), bright grains 21 and 21' and medium bright grains are classified regardless of the grain size. The grains 22, 22' and the dark grains 23, 23' each need to be similarly sorted.

However, in reality, the sorting level changes in the order shown in FIG. 5 depending on the shape of the grain. The reason for this is that even if the grains have the same brightness (color) but differ in size, the influence of reflected light from the background changes. That is, when the shape is small, the influence of the reflected light from the background is small, and when the shape is large, the influence of the reflected light from the background is large. For this reason, objects to be sorted that should be sorted only according to their brightness (color) are
There was a problem that the sorting accuracy was reduced due to the influence of the size.

[Problem that the invention seeks to solve]

Therefore, the present invention provides a color sorting machine that eliminates the influence of the size of objects to be sorted even when there is variation in size when color sorting is performed.

[Means for solving problems]

A first light source that illuminates the object to be sorted and the background, a first detector that detects reflected light from these, and a covered area having the same area as the spread of the reflected light from the background by the first light source. a second light source that illuminates the object to be sorted, a second detector that detects the light that is blocked by the object to be sorted, and a second light source that illuminates the object to be sorted; It has a half mirror (dichroic mirror) that selectively passes or blocks light.

[Effect]

The first detector detects the product of the area of the background minus the projected area of the object to be sorted on the background and the amount of reflected light per unit area of the background, the irradiated area of the object to be sorted and the object to be sorted. The sum of the product and the amount of reflected light per unit area is output. Further, the product of the area obtained by subtracting the irradiated area of the object to be sorted from the area of the background and the amount of light per unit area of the second light source is output to the second detector. Therefore, by processing these outputs, it is possible to eliminate the parameter of the size of the object to be sorted and to detect the amount of light proportional to the amount of reflected light per unit area of the object to be sorted.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In the figure, reference numeral 30 indicates the object to be sorted, and reference numeral 31 indicates the background. The object to be sorted 30 and its background 31 are illuminated by a first light source 32 . This first light source 32 uses, for example, a fluorescent lamp that emits light in the visible range but does not emit light in the near-infrared range. The reflected light from the object to be sorted 30 and its background 31 passes through a lens 33, a half mirror 34, and a visible range filter 35, and reaches a photodiode 36 (first detector).

Further, as the second light source 37, one that emits light in the near-infrared region, such as an incandescent light bulb, is used. The light from this second light source 37 passes through a near-infrared filter 38, is reflected by a half mirror 39, and is irradiated onto the object 30 to be sorted. The spread of the irradiated light is determined by the first light source 32
This is the same area as the spread of the reflected light from the background 31 due to this. The light from the second light source 37, which is partially blocked by the object to be sorted 30, passes through the lens 33 and is reflected by the half mirror 34, and then passes through the near-infrared filter 39' to the photodiode 40 (second light source 37). detector). Photodiode 3
Electrical signals from 6 and 40 are amplified by amplifiers 41 and 42, respectively. The output of the amplifier 41 is input to the addition input side of the adder 43, and the output of the amplifier 42 amplified by the amplifier 44 is input to the subtraction input side.
The output of is input. Further, the output of the amplifier 42 is input to the subtraction input side of an adder 45, and a constant potential V is marked on the addition input side. and,
The outputs of adders 43 and 45 are mutually divided by divider 46.
Division is performed by , and a signal proportional to the brightness of the object 30 to be sorted is output.

As shown in FIG. 2, the calculation here is performed as follows, assuming that the area of the background 31 is S and the area of the object to be sorted 30 is M. In addition,
The amount of reflected light per unit area on the background 31 is shown as a, the amount of reflected light per unit area on the object to be sorted 30 is shown as b, and the amount of near-infrared light per unit area of the second light source 37 is shown as c.

The spread of the second light source 37 is the same area S as the background 31, and the light from the second light source 37 is blocked by the object 30 to be sorted by the area M projected onto the background 31 of the object 30 to be sorted. From(2)
It becomes a ceremony. Also, equation (1) is clear from FIG.

First, the outputs of amplifiers 41 and 42 are expressed by equations (1) and (2), respectively.

(S-M)a+Mb...(1) (S-M)c...(2) Next, the gain K of the amplifier 44 is adjusted so that the output of the adder 43 when the object to be sorted 30 is not present is zero. After adjusting , the output of the adder 43 is expressed by equation (3). However, a=KC.

Mb...(3) On the other hand, if one input V of the adder 45 is adjusted so that the output of the adder 45 is zero when the object to be sorted 30 is not present, the output of the adder 45 is (4 ) expression. However, V=Sc.

Mc……(4) Therefore, the output of the divider 46 is expressed by equation (5).

b/c...(5) That is, regardless of the size of the object to be sorted 30,
On the other hand, a signal proportional to the amount of light reflected from the object to be sorted 30 per unit area is obtained. By comparing this signal with a reference value using a comparator to obtain an exclusion signal and performing the sorting, it is possible to perform highly accurate sorting regardless of the size of the objects 30 to be sorted.

〔Effect of the invention〕

In color sorting equipment, the sorting level that caused errors due to the size of the objects to be sorted has changed due to color (brightness).
The effect is that it is determined only by

[Brief explanation of drawings]

Fig. 1 is a diagram showing an embodiment of the color sorting machine for grains, etc. of the present invention, Fig. 2 is a diagram for explaining the areas of the objects to be sorted and the background, and Fig. 3 is a diagram of a conventional color sorting machine. A diagram showing an example, and FIGS. 4 and 5 are diagrams for explaining examples of errors in the conventional example. 30... Object to be sorted, 31... Background, 32... First light source, 34, 39... Half mirror, 36... First detector, 37... Second light source, 40... Third 2 detector.

Claims (1)

[Claims] 1. A first light source that illuminates the object to be sorted and the background, a first detector that detects light reflected from the object to be sorted and the background by the first light source, and a first light source that illuminates the object to be sorted and the background. a second light source that illuminates the object to be sorted and has the same area as the spread of reflected light of the object; and a second light source that detects light from the second light source other than the light that is blocked by the object to be sorted. a detector; a half mirror that distinguishes light from the first light source and light from the second light source and guides them to the first detector and the second detector, respectively; The output of the first detector and the second detector
1. A color sorting machine for grains, etc., characterized in that the output of a detector is processed and the influence of the size of the objects to be sorted on the color judgment of the objects to be sorted is removed.