JPH0146194B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is a method for comparing objects having predetermined characteristics and objects not having predetermined characteristics, that is, preferable objects and undesirable objects. The present invention relates to a sorting device that separates

The term "object" is used herein in a broad sense and is intended to include agricultural products such as rice, peas, soybeans, etc., as well as fine particulate and lump minerals. The term "property" is also used herein in a broad sense to include color, reflectance, light transmission, electrical conductivity, magnetism, fluorescence, and emissivity.

[Prior Art] In known sorting devices with a plurality of detectors for testing a plurality of objects arranged on one support, each detector tests a group of such objects. is configured to do so. The response of the detector to a property of the objects being tested is therefore determined by the average value of said property in the group of objects. However, such average values do not necessarily provide good criteria for selection.

For example, if the purpose of sorting is to remove dark-colored objects, when a detector simultaneously observes one object to be removed and several light-colored objects, the detector It is possible to be deceived. This is because the average color of the group may be acceptable despite the presence of dark colored objects. A similar problem may occur if each support carries objects arranged in a single file. In this case as well, if one object has a light colored part and a dark colored part, it is not necessarily removed.

Additionally, the sorting device typically views the object to be sorted against a background having a color that matches the average color of the object to be sorted. Such a background will compensate for the effects caused by changes in the dimensions of the objects to be sorted. However, the effective colors of both the background and objects are subject to change. For example, the background and object may each be illuminated by fluorescent lamps that age at different rates and/or unevenly over their length in different ways. The light output ratio of such multiple fluorescent lamps also varies depending on the amount of dust that accumulates on them. Furthermore, although the average color of the objects to be sorted is usually substantially constant,
Even when the products to be sorted are the same, there are usually slow but random changes in their average color. If the products to be sorted change to similar but different products, changes in average color are even more likely to occur.

Furthermore, when the sorting device is a multi-passage device, the objects passing through the different channels will not necessarily all have the same average color, and for the reasons mentioned above, the backgrounds of the different channels will not necessarily have the same effective color. is not limited.

An object of the present invention is to provide a sorting device that can always perform accurate sorting even if the background or color of the object changes.

Preferably, according to the present invention, the following sorting device is provided. That is, an observation device that observes an object to be sorted passing in front of a background within a predetermined field of view in a sorting band and detects reflection, transmission, or emission of light in a predetermined portion of the spectrum within the field of view; the background provided within the field of view of the device; a feeding device for causing the object to pass in front of the background in the sorting zone so that the object is observed against the background; and the sorting zone. a separation device for relatively separating the object observed as undesirable from the remaining objects; and an instruction to the separation device to separate the undesirable object according to the detection result from the observation device. The sorting device further includes a testing device 16,
17, for causing the observation device to detect the reflection, transmission or emission of light only by the background; and adjusting the reflection, transmission or emission of light by the background, or adjusting the light incident on the object. an adjustment device for performing adjustment, and the test device receives a detection result representing an average value of light from both the background and the object within the predetermined field of view from the observation device while the object is being supplied. The test device periodically receives detection results representing reflection, transmission, or emission of light only by the background during the supply stop of the object from the observation device; The detection result received from the device is compared with the detection result received while the object is stopped, and the adjustment device is made to make the adjustment according to the comparison result while the object is being sorted, so that the light due only to the background is The sorting device is provided which maintains a predetermined relationship between the reflection, transmission or radiation of light and the average reflection, transmission or radiation of light only from the object.

Said testing and adjustment makes it possible to maintain the reflection, transmission or emission of light from the background in said predetermined relationship with that of the average of the object. As will be appreciated, in many cases the "predetermined relationship" is equivalence, ie, the color of the background matches the average color of the object. However, if desired, the background can be made this intentionally mismatched color to the average color of the object. However, this is provided that this mismatch remains constant.

Hereinafter, the following aspects of the present invention can be considered.

The test equipment measures the average reflection, transmission, or emission of the collective light between the background and the object immediately before stopping.
Includes a comparison device that compares the background-only reflection, transmission or emission during the stop period.

Preferably, the observation device is a photoelectric observation device, and the test device includes an averaging circuit for generating a voltage signal representative of the average electrical output of the observation device, and the test device also receives the voltage signal and an electrical device for receiving another voltage signal representative of the instantaneous electrical output of the observation device during an object supply stop, the electrical device generating a difference signal being the difference between the two voltage signals to adjust the adjustment; It is designed to control the device.

The electrical device includes a processor that controls the feed device, and the processor is programmed to stop the feed device at time intervals having a length inversely proportional to the magnitude of the difference signal.

When the adjustment device is controlled by an electrical device and a difference signal occurs in a test, said adjustment resulting therefrom is different in the next test, as being insufficient to restore said relationship at the beginning. said electrical device is configured to generate a difference signal of two successive difference signals and determine from the magnitude of these two successive difference signals the signal necessary to be sent to said adjustment device to complete said adjustment. has been done.

Means are provided for operation during each said stop period to measure the output of the observation device and provide a correction factor to the electrical device as required to maintain the sensitivity of the observation device substantially constant.

Means is provided for operating during the period in which the object passes in front of the background to indicate an undesirable object separation ratio.

The adjustment device includes a motor for changing the angular position of the background.

At least one light source illuminates the background or object, and the adjustment device includes a device for varying the light output of the light source.

The background includes a light emitting diode or a liquid crystal material,
The adjustment device is configured to vary the total light output of the light emitting diode or liquid crystal material.

Another aspect of the invention includes at least one set of a plurality of separate but adjacent supports for conveying the object to the sorting zone, each support having a plurality of detectors; Each detector shall be responsive to said characteristic, and each detector shall be responsive to objects located only in, or transmitted to said sorting zone from a respective portion of a respective support. The sorting device is provided with means for ensuring that it is operative.

The detectors are preferably light sensitive detectors and are provided with lens means for forming an image of the respective object on each detector.

A common background observed by the detector is provided for each of the plurality of supports, each background being located on a side of the support opposite to the side on which the detector is located. be done. Thus, the images are focused on the detector and each common background is taken out of focus.

a plurality of groups of supports, each group including said plurality of separate but adjacent supports, each group varying the reflectance or light transmission or emission of each background independently of the values of the other backgrounds; equipped with a device to In this case, the backgrounds of said groups are arranged close to each other, and each said group is spaced from an adjacent group equal to at least one third of said groups.

Apparatus for varying the reflectance include apparatus for varying the angular positioning of each background.

Alternatively or additionally, the device for varying reflectance includes one or more light sources for each background, the output of which impinges on the respective background. A device is provided for varying the light output or varying the amount of light that falls on each background.

Another possibility is to provide each background with a light emitting diode or liquid crystal material and a device for varying the output of the light emitting diode or liquid crystal material.

Preferably, the object passes through the sorting zone in free fall.

The separating device includes an ejector for removing the sorted objects during descent through the sorting zone, each support having one ejector. Each ejector is a compressed air ejector that provides a jet of air to the sorted objects.

Preferably, each of the supports is configured to simultaneously carry a plurality of said objects in a row, and each support preferably includes a substantially flat-bottomed chute.

Apparatus is provided to periodically adjust the output of the detector to maintain the sensitivity of the detector substantially constant as required.

EMBODIMENTS OF THE INVENTION The invention is illustrated by way of example only in the accompanying drawings, in which: FIG.

Referring to the drawings, FIG.
Although only passage groups are shown, the sorting device for sorting rice by reflectance includes a plurality (for example, 10) of passage groups 10. Each passageway group 10 includes a plurality (eg, four) of separate but adjacent substantially vertical passageways or chutes 11. Each chute 11, which is a support, has a substantially flat bottom 12 and supports a plurality of (for example four) rice grains 1 in a row.
3 are supported and conveyed simultaneously to the sorting zone 14.

The passage groups 10 are arranged in two assemblies of 105 such groups (therefore 20 passages).
A respective rice hopper 15 is mounted on each of the five groups 10 of assemblies, and a vibrating table 16 receives the rice grains from each hopper 15, and an electromagnetic vibrator or Another vibrator 17 vibrates the vibration table 16,
The rice grains 13 above it are supplied.
In operation, each vibrator 17 removes rice grains 13 from its respective hopper 15 into all its respective chute 1.
Supply to the top of 1. Rice grains 13 are each shoot 11
It falls by gravity from the bottom of the screen and passes through the sorting zone 14.

A photoelectric observation device in which a plurality (for example, 16) of photocells or other light-sensitive detectors 20 are provided in each of four groups of shoots 11 for observing objects 13 to be sorted in a sorting zone 14. Configure. Each lens (or lens system) 21
is the rice grain 1 that falls through the sorting zone 14 as a result of being conveyed from each chute 11 to the sorting zone.
3 images are focused onto a plurality of detectors 20.

One common background 22 observed out of focus by each detector 20 Four shoots 1
1 for each group 10. Each background 22
is provided on the side of the passage group 10 opposite to the side on which the detector is arranged. Each background 22 has 13 rice grains
The average color, i.e., the average reflectance of the rice grain in a part of the spectrum, is either matched or mismatched to the rice grain at a predetermined rate, so that the detector 2
The signal generated by 0 is virtually unaffected by changes in grain size. Although the backgrounds 22 are arranged close to each other, since the background 22 is out of focus and the rice grains 13 are in focus, each group 10 of four shoots 11 is separated from its neighboring group by a wide distance, e.g. be spaced at a distance equal to at least one third of the width of the

Two fluorescent tubes 23 are provided to illuminate each rice grain 13 falling through the sorting zone 14, and one fluorescent tube 23a illuminates all the background 22.
It is set up so that the light shines on it.

Each chute 11 is associated with a compressed air eliminator 24. Each ejector 24 is connected to a source of compressed air (not shown) and includes an electrically operated valve (not shown). It opens and closes under the control of an eliminator drive device 25 driven by a processor 26. A plurality of processors 26 are provided, one for each group 10 of four shoots 11. Each processor 26 is
Since it is controlled by the signal from each detector 20, for example, dark colored rice grains or discolored rice grains 1
3 is detected by any of the detectors 20, the valve opens and compressed air is ejected and sprayed towards the discolored rice grains. As a result, the path of movement of the discolored rice grains changes, and the discolored rice grains do not reach the storage box 27 and reach the removal box 2.
Reach 8.

As can be seen in FIG. 2, the provision of lenses 21 means that each detector 20 operates in response to rice grains 13 delivered to sorting zone 14 from a respective portion of a respective chute, and also has a respective background. Ensure that it operates in response to its counterpart. For example, the leftmost detector 20a of each of the plurality of detectors 20 detects rice grains 13 falling from the rightmost rightmost portion 11a of each chute 11.
At the same time, the corresponding portions 22a of each background 22 are observed. Similarly, detector 20
b, 20c, and 20d observe only the rice grains at the rightmost portions 11b, 11c, and 11d of the chute 11, as well as the corresponding background portions 22b, 22c, and 22d, respectively. Therefore, if the width of each portion of the chute 11 is such that it can only accept one grain of rice 13 at a time, each detector 20 will observe only one grain of rice 13 at a time during operation. ,
The resolution of the sorting device, ie the ability to detect defective rice grains, is much higher than if each detector were to observe two or more rice grains at a time.

The reflectance of each background 22 can vary independently of the reflectance of other backgrounds 22. This variation is in order to be able to compensate for changes in the average color of the rice passing through different parts of the sorting device and for changes in the effective color of the background caused by dust and aging of the fluorescent tubes. desirable. That is, if the average color of the rice passing through the entire sorting device changes gradually (in fact, no abrupt changes occur), it is desirable to change the effective color of all backgrounds 22 correspondingly. On the other hand, if the average color of the rice on one side of the sorting device varies somewhat with respect to the average color of the rice on the other side, it may be desirable to change the relative color of each background.

For this purpose, each background 22 has a pivot 30
It is mounted on top of the motor 31 so that it can be rotated by each motor 31. Such rotational movement of the background 22 is controlled by a background brightness controller 32, which in turn is controlled by the processor 26. Due to this rotational movement of the background 22,
Fluorescent tubes 23 reflecting towards their respective detectors 20
The effective color of the background is changed by changing the amount of light a.

Alternatively or additionally, for each background 22 one or more light sources 33 are provided so that their light output falls on the respective background 22. light source 33
The light sources may be flashable, their positions with respect to the background may be adjusted, or the light output of the light sources may be varied by respective controllers 34 connected to respective background brightness controllers 32.

Alternatively or additionally, the light from the light sources 33 may be applied to the respective backgrounds 22 after passing through the respective rotating optical wedges 35 . The angular positioning of the rotating optical wedges 35 is controlled by respective background brightness controllers 32.

Another possibility is that each background 22 comprises a collection of light emitting diodes (not shown) or a liquid crystal material (not shown), and each background brightness controller 32 comprises a collection of light emitting diodes (not shown) or a liquid crystal material (not shown). The objective is to be able to vary the overall light output of the material.

Alternatively or additionally, fluorescent tubes 23, 23a
It is possible to adjust the relative position and relative light output of.

Each group of four detectors 20 simultaneously observes the object 13 and an unobstructed portion of the background 22 in front of which the object 13 is free-falling. However, as described below, when the supply of objects is stopped, only the respective backgrounds are observed. Thus, when supplied, these detector 20 electrical outputs represent the reflectance of the object 13 and the respective background in a given portion of the spectrum. In the absence of supply, the output of the detector represents the reflectance of only the respective background 22 in said predetermined portion of the spectrum.

4 adjacent detectors 2 attached to each chute 11
4 outputs 20a, 20b, 20c, 2 from 0
0d is applied to each DC-coupled preamplifier 36. Each preamplifier 36 has one output, and four outputs 37 are connected to each processor 26.
added to.

Each processor 26 has four outputs 37.
digital/analog, analog/digital interface 42 (see Figure 3) that receives
including. Each processor 26 additionally has four
low pass filter 4 receiving one of the outputs of
It has an averaging circuit including 1. This low pass filter 4
The DC output 43 of 1 is also digital/analog,
Received by analog/digital interface 42. Output 37 may also be AC coupled to an analog/digital, digital/analog interface 42. Each processor 26 includes an interface 42 as well as a microprocessor unit 44, a program memory 45, a random access memory 46, and a bus system 5.
It has an input/output device 47 interconnected by 0. Output conductor 5 from input/output device 47 of each processor 26
1 extends to each vibrator 17, and the output conductor 5
2 extend to the respective background brightness controller 32 , and the output conductor 49 extends to the excluder 24 .

The program memory 45 of each processor 26 is
It is programmed to periodically send a signal to each input/output device 47 to cause an output from the input/output device to output lead 51 . When an output is generated on the output conductor 51, each vibrator 17 is stopped for a predetermined period, for example, 5 seconds, and then restarted. The voltage signal generated by each low-pass filter 41 is the output from each detector 20, that is, the voltage signal immediately before stopping.
The signal represents the average value of the reflection of light both by the undisturbed portion of each background 22 and by the object 13 passing in front of the background. On the other hand, the voltage signal produced at the output 37 represents the instantaneous value of the output from the respective detector 20 and represents the instantaneous value of the reflection of light from the respective background 22 alone during the stop period. The two voltage signals are compared at the interface 42 of each processor 26 to generate a difference voltage signal, which is the difference between the two voltages. When each color is selected to correspond exactly to the average color of the object, the differential voltage will be zero unless a relative color change occurs between the background color and the object color. On the other hand, if the background is intentionally made mismatched with the average color of the object, the differential voltage will be a predetermined value, but in this case the difference between the actual value of the differential voltage and the predetermined value will be used for subsequent control. can be used to perform.

Assuming, as is usually the case, that the background color corresponds to the average color of the object, the difference signal is processed in each processor 26 and sent to a respective background brightness controller 32 and, after a delay, to a respective The output is given to the vibrator 17 of. Background brightness controller 3
2, upon receiving such output, rotates the respective motor 31 and/or rotates the respective optical wedge 35 to adjust the angular position of the respective background 22 as required; The light output of each light source 33 is adjusted via a controller 34 of the light source 33 . In this case, the amount of light reflected from each background is increased or decreased as necessary to maintain the correspondence between the background color and the average color of the object.

The output 51 applied to each vibrator 17 is
is used to temporarily stop the supply to the twenty shoots 11, the output 51 of which is delayed by a period inversely proportional to the magnitude of the difference signal. Therefore, each processor 2
When the maximum difference signal among the difference signals from 6 is small, the vibrator 17 is stopped at long intervals, but when the maximum difference signal is large, the vibrator 17 is stopped at short intervals.

See FIG. 4, which is a graph illustrating the output from detector 20 when the brightness of each background does not match the average brightness of the object being observed. V _P is the average voltage generated by the detector 20 when the object is present, ie, during supply. V _N is when the object does not exist, i.e.
This is the voltage generated by the detector 20 while it is stopped. Obviously V _P ≠V _N .

That is, when the object 13 is not observed by the detector, the voltage V _N generated by the detector is due to the reflectance of the background 22 alone. However, when an object 13 with a reflectance greater or less than that of the background 22 is observed by the detector, pulses 53 and 54 are generated, respectively.

The voltage V _P is determined by the average reflectivity of the object 13 in the portion of the spectrum to which the detector responds and the average amount of object within the field of view of the detector 20 . FIG. 5 shows the field of view of the detector 20, which is constituted by a rectangular area 55 having a length l ₁ and a width l ₂ . The objects 13a, 13b and 13c are passing through the field of view 55, and have areas A ₁ , A ₂ and A ₃ within the field of view 55, respectively.
It is shown as having .

Therefore, if the brightness of the background 22 is intended to be the same as the average brightness of the object 13, then the background 22 when no object is provided in front of the background
It is necessary to change the brightness of from the original value V _N to the new value N _N2 . Here, V _N2 = V _N + (V _P - V _N ) F = Area of field of view 55 / Average area of objects within field of view = l ₁ · l ₂ / (A ₁ + A ₂ + A ₃ ) F is load For a given object 13, the field of view 55 when that object is being supplied.
It depends primarily on the average amount of objects 13 inside. A load factor F also exists in the throughput, but a given constant load factor can be treated as a fixed one, and in order to set the brightness of the background 22 in the processor 26 to the correct value for the equilibrium condition. Can be used.

However, in programming the processor 26, it is desirable to select a load factor F that is smaller than the actual load factor F in order to correctly set the background. Therefore, during the first outage period, the background adjustment resulting from the generation of the difference signal is insufficient to completely restore the background brightness to just match the average brightness of the object 13. The background is adjusted sequentially during subsequent pauses to reach the correct limits. On the contrary,
If the load factor chosen is too large, there is a risk that the background will constantly adjust around the average position at each stop.

In FIG. 6, it is assumed that the background is initially set at point X and that the supply of objects passing in front of the background is stopped. In this case, the voltage generated in the detector 20 when no object is present is _VN ,
It is also assumed that the above-mentioned differential voltage is V. Further, assume that as a result of estimating the load factor F to be small as described above, insufficient adjustment of the background is performed and the adjustment is made to the point indicated by Y. As a result, it is found that the background is not sufficiently adjusted during the next stop period, and it is assumed that the voltage generated by the detector 20 when no object is present is V _N1 and the differential voltage is V ₁ . . In this case, the correct load factor F at the set point Z representing the correct setting of the background by similar triangles can be assumed to be F=V _N2 -V _N /V and F=V _N1 -V _N /V-V ₁ .

Since V _N1 , V _N , V and V ₁ have all been previously measured, the exact value of F can be determined. To arrive at the correct Z setting from the Y setting, consider the fact that V _N2 = V _N1 + (V ₁ ×F) V _N2 = V _N1 + V/V−V ₁ (V _N1 −V _N ).

Each processor 26 is programmed to perform the above calculations, including recalculating the load factor F, during each outage period.

During each stop period, each processor 26
The output of each DC-coupled preamplifier 36 is tested to determine if the zero sensitivity has changed, and if necessary, a correction factor of the processor 26 is applied to keep the effective sensitivity of the detector 20 substantially constant. programmed to maintain.

As the object passes in front of the background 22 and while the object is selected, each processor 26 measures the average separation ratio of the objectionable object and sends a signal through output line 60 to a respective display. It is programmed as follows.

In another embodiment, particularly applied to a multi-pass sorter, information regarding the average separation ratio from each processor 20 is sent to a central management processor. The central processor now calculates the average value of the average separation ratio for each aisle, compares the average value to the individual separation ratios, and determines the difference between the individual separation ratios for a particular aisle and the average value. ing. A display (not shown) is provided to indicate to the operator of the device which passages are above or below the average value.

Although the invention has been described with reference to the reflection of light by the object 13 and the background 22, the invention also examines the transmission of light through the object or the emission of light from the object, e.g. fluorescence. It can also be applied to sorting equipment. Similarly, light from the background can be transmitted or emitted from the background.

Furthermore, although the present invention has been described with respect to monochromatic light sorting, the present invention is also applicable to dichromatic light sorting. 2
In color light screening, the object 13 is tested by determining whether the proportion of light from the object in a certain portion of the spectrum is outside certain limits.

It should be noted that in the above description, adjustments with respect to the background are made to adjust the reflection, transmission or emission of light, for example by changing the reflectance of the background. However, instead (or in addition), the desired adjustment can be made by adjusting the light incident on the object. For example, each aisle could have its own light source (not shown) and the light could shine on its own object, but the light source could not shine on objects in other aisles. A device for varying the light output can be provided.

According to the present invention, since the supply of the objects to be sorted is periodically stopped and each time a test is made to see if there is a predetermined comparison relationship between the objects and the background, for example, the objects to be sorted are Even if the average color of the lighting device changes or the light output of the illumination device gradually decreases, this can be corrected and accurate sorting can be performed, which is an excellent effect.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of a sorting device according to the present invention, FIG. 2 is a diagram showing a part of the sorting device of FIG. 1,
Fig. 3 is a block diagram of a processor forming part of the structure shown in Fig. 1, Fig. 4 is a diagram showing the output of the detector shown in Figs. A diagram illustrating the pattern in which the object is viewed and FIG. 6 is a diagram illustrating how the correct differential voltage is derived by the processor to supply the background brightness controller. 11... Shoot which is a supporter, 13, 13
a, 13b, 13c...object, 20, 20a,
20b, 20c...detector, 21...lens, 2
2... Background, 24... Excluder, 26... Processor, 33... Light source.

Claims (1)

[Claims] 1. The background 22 within a predetermined field of view in the screening zone 14
Observe the object 13 to be sorted passing in front of the
Observation device 2 that detects reflection, transmission or emission of light in a predetermined part of the spectrum within its field of view
0, the background 22 provided within the field of view of the observation device 20, and the background 22 arranged on the object 13 in the screening zone 14 so that the object 13 is observed against the background 22; a separating device 24 for relatively separating the objects observed as unfavorable in the sorting zone 14 from the remaining objects; In the sorting device including a testing device 26 that instructs the separating device 24 to perform relative separation of undesirable objects according to the detection result, the feeding devices 16 and 17 are further temporarily stopped to detect the background 22 only. A stop device 45 that allows the observation device 20 to detect reflection, transmission or radiation of light.
and an adjustment device 32 that adjusts the reflection, transmission, or radiation of light by the background 22 or adjusts the light incident on the object, and the test device 26 is operated while the object is being supplied. Detection results representing the average value of light from both the background 22 and the object 13 within the predetermined field of view are periodically received from the observation device 20, and the detection result representing the average value of light from both the background 22 and the object 13 within the predetermined field of view is periodically received from the observation device 20, and when the supply of the object is stopped, the detection result representing the average value of light from both the background 22 and the object 13 is The testing device 26 receives a detection result from the observation device 20 during the supply of the object while the supply of the object is stopped. The adjustment device 3
2 to perform the adjustment so as to maintain a predetermined relationship between the reflection, transmission, or radiation of light only by the background 22 and the reflection, transmission, or radiation of light by the average of only the object. . 2. In the sorting device according to claim 1, the testing device 26 detects the background 22 immediately before stopping.
The average reflection, transmission or emission of the collective light between and the object 13, the reflection of only the background during the stop period,
Said screening device comprising a comparison device 26 for comparison with transmission or radiation. 3. In the sorting device according to claim 2, the observation device is a photoelectric observation device, the test device 26 includes an averaging circuit that generates a voltage signal representing the average electrical output of the observation device 20, The test device 26 also includes an electrical device 2 for receiving the voltage signal and for receiving another voltage signal representative of the instantaneous electrical output of the observation device 20 during the object supply stop.
6, wherein the electrical device 26 is adapted to generate a difference signal that is the difference between the two voltage signals to control the regulating device 32. 4. The sorting device according to claim 3, wherein the electrical device includes a processor 26 for controlling the supply devices 16, 17, the processor having a length inversely proportional to the magnitude of the difference signal. The sorting device is programmed to stop the feeding devices 16, 17 at time intervals. 5. In the sorting device according to claim 3 or 4, the adjustment device 32 is controlled by the electrical device 26 so that when a difference signal is generated in the test, said adjustment caused thereby , in order to complete said adjustment from the magnitude of these two successive difference signals by generating another difference signal in the next test, initially insufficient to restore said relationship. the sorting device, wherein the electrical device 26 is configured to determine the signals needed to be sent to the conditioning device 32; 6. In the sorting device according to any one of claims 1 to 5, operating during each of the stop periods and measuring the output of the observation device 20,
The sorting device comprises means for applying a correction factor to the electrical device 26 as required to maintain the sensitivity of the viewing device 20 substantially constant. 7. The sorting device according to any one of claims 1 to 6 operates during the period when the object 13 passes in front of the background 22 to reduce the separation ratio of unfavorable objects. Said sorting device comprising means for instructing. 8. In the sorting device according to any one of claims 1 to 7, the adjusting device 32
The sorting device includes a motor 31 for changing the angular position of the background. 9. The sorting device according to any one of claims 1 to 8, comprising at least one light source 33 that illuminates the background 22 or the object 13, and the adjusting device 32 Said sorting device comprising a device 34 for varying the light output of the light source 33. 10. The sorting device according to any one of claims 1 to 9, wherein the background 22 comprises a light emitting diode or liquid crystal material, and the adjusting device 32 adjusts the total light output of the light emitting diode or liquid crystal material. The sorting device is configured to change. 11. In the sorting device according to any one of claims 1 to 10, the object 1
3 to the sorting zone 14, at least one set (10) of a plurality of separate but adjacent supports 11 are provided, each support 11 having a plurality of detectors 20.
, each detector 20 being responsive to said characteristic, and each detector 20 being responsive to a respective support 1
means 2 for ensuring that the means 2 operate in response to objects that are only in the respective parts 11a of 1 or that are transmitted from the respective parts 11a to the sorting zone;
1. 12. In the sorting device according to claim 11, the detector 20 is a photosensitive detector,
Each object 13 on each detector 20
Said sorting device comprising lens means 21 for forming an image of. 13. In the sorting device according to claim 12, a common background 22 observed by the detector 20 is provided for each of the plurality of supports 10, and each background 22 is provided with a common background 22 observed by the detector 20. The sorting device is placed on the side of the supporter opposite to the side where the detector 20 is placed. 14. A sorting device according to claim 13, wherein the lens means 21 focuses the image onto the detector 20 and each common background 22 is out of focus. 15. The sorting device according to claim 14, comprising a plurality of groups 10 of supports 11, each group 1
0 includes said plurality of separate but adjacent supports 11 and comprises a device 31 for varying the reflectance or light transmission or emission of each background 22 independently of the values of other backgrounds. Device. 16. The sorting device according to claim 15, wherein the backgrounds 22 of said groups 10 are arranged close to each other, and each said group is spaced from an adjacent group equal to at least one third of said groups. said sorting device. 17. In the sorting device according to any one of claims 11 to 16, the separating device 24 includes an excluder 24 for removing the sorted objects 13 while descending the sorting zone 14. , and each supporter 11 has one excluder 24. 18. In the sorting device according to any one of claims 11 to 17, each of the supports 11 has a plurality of objects 13 arranged in a row.
The sorting device is configured to simultaneously transport. 19. The sorting device of claim 18, wherein each support 11 includes a substantially flat-bottomed chute.