JPH09269265A - Heterogeneous glass distinguishing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct distinguishing of sodium glass and non-sodium glass by an optical device. SOLUTION: An interference filter 7 passing only light flux having a wavelength of 2800nm ±5% is provided between a light projecting portion 21 and a light receiving portion 22 so as to form a first optical path 11, and a second optical path 12 having no interference filter 7 is provided in parallel thereto. A glass piece 6 is arranged extending over both optical paths 11, 12, in the first optical path 11 the light flux having a wavelength of an infrared range penetrated the interference filter 7 is irradiated on the glass piece 6, and in the second optical path 12 visible light itself is irradiated. In the first optical path 11 sodium glass and non-sodium glass are judged, in the second optical path 12 stain and the like on the surface of the glass piece 6 are detected, and considering the degree of the stain, misjudgement between the sodium glass and the non-sodium glass in the first optical path 11 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for distinguishing foreign glass, and more particularly to a device for optically distinguishing sodium glass from non-sodium glass.

[0002]

2. Description of the Related Art Glass bottles and glass containers in waste include those that are partially chipped or cracked, and those that are broken into pieces of glass or have a perfect shape. Using as a raw material, glass is melted and solidified, and glass is newly recycled and reused.

At this time, in order to increase the purity of the recycled glass,
Although classification is performed in advance based on the difference in color, an identifying operation for that purpose is performed using an optical device such as an image processing device or a color sensor.

[0004]

By the way, most of ordinary glass bottles and containers are made of sodium glass, but as described above, used glass bottles and containers are used as raw materials.
When non-sodium glass such as heat-resistant glass or crystal glass is mixed with this sodium glass when it is melted and solidified to newly regenerate the glass, the regenerated glass is pure sodium glass in terms of strength and other properties. It comes to have various drawbacks compared to.

Therefore, when the glass is melted and recycled, it is necessary to separate the sodium glass from the non-sodium glass in addition to the separation based on the difference in color.

The sodium glass and the non-sodium glass can be discriminated from each other based on the difference in specific gravity between them, but a device for performing such an operation is generally a mechanical device having a function such as weight measurement. Therefore, the device has a completely different specification from the optical device for performing the discrimination based on the color difference.

If such a mechanical device of another specification is incorporated into an optical device for discriminating operation based on a difference in color and it is attempted to discriminate between sodium glass and non-sodium glass based on the difference in specific gravity between them, The configuration of the entire identification device becomes complicated.

Therefore, if the sodium glass and the non-sodium glass can be discriminated by the optical device, the entire discriminating device can be performed by the single optical device, and the device parts can also be used to simplify the entire device.

Therefore, an object of the present invention is to enable the optical device to distinguish between sodium glass and non-sodium glass.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention receives a transmitted light of a reference light emitted from a light projecting portion onto a glass to be detected by a light receiving portion, detects the amount of received light, and detects a different amount. An apparatus for identifying glass, wherein the reference light is visible light, and an interference filter for passing only a light flux having a wavelength of 2800 nm ± 5% is provided between the light projecting unit and the light receiving unit, and the interference filter is passed. Irradiate the detected light beam on the glass to be detected,
The sodium glass and the non-sodium glass are distinguished from each other (Claim 1).

By doing so, 2800 nm
Since the luminous flux of ± 5% has different transmittance between sodium glass and non-sodium glass, if the luminous flux with the wavelength with a large difference in transmittance is irradiated, the amount of received light is measured and the two are distinguished. can do.

In the above structure, the optical path having the interference filter is the first optical path, the second optical path having no interference filter is provided in parallel with the first optical path, and the glass to be detected is provided on both sides. It can be configured to be arranged over the optical path and irradiate the glass to be detected with visible light in the second optical path (claim 2).

According to this structure, there is no difference in the transmittance of visible light between the sodium glass and the non-sodium glass, which have a small degree of dirt or irregularities on the surface or a small thickness. If there is a change in the amount of light received in the second optical path for irradiating the light, it is based on such stains and irregularities on the glass surface or the difference in the thickness of the glass. Therefore, in the second optical path, it is possible to identify by the elements different from those of the first optical path, and by these elements, it is possible to prevent erroneous recognition of the detected glass in the first optical path.

For example, when soiled sodium glass is placed at the determination positions of both optical paths, the contamination of the first optical path reduces the luminous flux of the infrared wavelength that passes through the sodium glass, and the received light amount is small. Even if it is detected and erroneously determined as non-sodium glass, the degree of contamination can be determined in the second optical path as described above. Therefore, the degree of contamination and the amount of light received by the first optical path can be determined. The glass to be detected in the first optical path can be identified in consideration of these two factors. The details of this principle will be described in detail in the following embodiments.

The second aspect of the present invention is the second aspect.
It is also possible to provide an interference filter in the optical path and use the interference filter having a characteristic of transmitting only the light flux having a wavelength of 1800 nm ± 5% (claim 3).

Also in this structure, as in the case of irradiating visible light in the second optical path, there is no difference in the amount of transmitted light due to the difference in the types of glass to be detected (sodium glass and non-sodium glass), and the second optical path is used. If the amount of light received in the optical path is detected, the glass to be detected can be identified by the stains on the glass surface, the degree of unevenness, the difference in thickness, etc., as described above.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings. (First Embodiment) Optical identification device 10 of this embodiment
Is provided with two optical paths 11 and 12, as shown in FIG.
The light source 1 and the condenser lens 2 are arranged in the light projecting unit 21 for both the optical paths 11 and 12, and a halogen lamp is used as the light source 1.

As the light receiving element 3, a PbSe photoconductive element capable of detecting light with a wavelength of 5 μm is arranged in the light receiving section 22. An arithmetic circuit 5 for measuring the amount of received light is connected to this photoconductive element via an amplifier 4. An operational amplifier is used as the amplifier 4.

A personal computer is used as the arithmetic circuit 5, and the personal computer is further connected to a foreign glass removing device, which will be described later, to send a signal indicating the discrimination result of sodium glass and non-sodium glass.

At the time of inspection, the glass piece 6 to be detected is arranged between the condenser lens 2 of the light projecting portion 21 and the light receiving element 3 of the light receiving portion 22 so as to extend over both optical paths 11 and 12.

Then, one of the two optical paths 11 and 12 (on the left side of the drawing, this optical path is hereinafter referred to as a first optical path 11,
An optical path on the right side of the drawing is referred to as a second optical path 12), and interference occurs between the condenser lens 2 of the light projecting portion 21 and the glass piece 6 and between the glass piece 6 and the light receiving element 3 of the light receiving portion 22. The filter 7 is arranged. The interference filter 7 is a filter that transmits, absorbs, or reflects only light within a certain wavelength range by utilizing the interference of light in a thin film made of a dielectric material. Also, an interference filter for transmission formed by overlapping is used, and only the light of the wavelength in the infrared region is extracted from the light of the halogen lamp by the interference filter 7. A light flux of 2800 nm was extracted as light having a wavelength in the infrared region. However, for light having a wavelength in the vicinity (± 5%) of this, as will be described later, for sodium glass and non-sodium glass, it is between them. There is a large difference in transmission amount.

On the other hand, in the second optical path 12, this interference filter is not provided, and the glass piece 6 is directly irradiated with the light of the halogen lamp of the light source 1. Since the light of the halogen lamp itself is visible light, the portion of the glass piece 6 placed on the second optical path 12 is irradiated with visible light.

The above is the configuration of the optical discriminating apparatus 10 for discriminating between sodium glass and non-sodium glass. On the upstream side of the optical discriminating apparatus 10, a glass piece supply device for supplying the glass piece 6 to the optical discriminating apparatus 10. (Not shown) is arranged, and a glass piece removing device (not shown) for mechanically removing either the identified non-sodium glass or sodium glass from the passage is arranged on the downstream side.

The arithmetic circuit 5 of the optical discriminating device 10 and the removing device are connected by a transmission signal path (not shown), and the discriminating device receives the discriminating signal of the glass piece 6 from the arithmetic circuit 5 as described above. Will be sent.

In the bottles and glass containers collected from the waste, those that remain intact and have a large shape or large pieces are preliminarily crushed by a crusher to receive light from the projecting section 21 and the light receiving section. It is crushed to a size that allows it to pass through the section 22 and sent to the glass piece supply device.

The glass pieces 6 sent to the optical discriminating apparatus 10 under the above-described apparatus configuration are sorted into sodium glass and non-sodium glass as follows.

First, the glass piece 6 sent to the optical discriminating device 10 is placed between the interference filters 7, 7 on the light projecting portion 21 side and the light receiving portion 22 side, and the light source 1 to the light receiving portion 22 side. Is irradiated with light.

The light emitted from the halogen lamp of the light source 1 is in the first optical path 11 the interference filter 7 on the side of the light projecting section 21.
Only light having a wavelength of 2800 nm in the infrared region is selected by the irradiation, and this light is applied to the glass piece 6 in the portion mounted on the first optical path 11. When the glass is colored, the light having a wavelength in the infrared region transmits sodium glass and hardly transmits non-sodium glass.

Therefore, when the light passes through the glass piece 6 and reaches the light receiving portion 22 side, the glass piece 6 is determined to be sodium glass.

If the glass piece 6 is colorless and transparent, 28
30% of the light with a wavelength of 00 nm ± 5% passes through sodium glass, and the transmittance of non-sodium glass is 5%.
Therefore, sodium glass and non-sodium glass can be distinguished from each other by this difference in transmittance.

It is to be noted that the interference filters 7 and 7 are provided on both the light projecting portion 21 side and the light receiving portion 22 side when the interference filter 7 is only on the light projecting portion 21 side as shown in FIG. 2A. Since the ambient light 23 has a high probability of entering the device and the accuracy of the determination cannot be maintained, the ambient light is removed by the interference filter 7 provided on the light receiving portion 22 side as shown in FIG. This is because only the light flux having the wavelength that should reach

By the way, the glass bottles / containers or the fragments thereof collected as wastes actually have dust or dirt attached to the surface, fine irregularities exist, and various thicknesses. There is. Therefore, even if it is attempted to discriminate the glass piece 6 in such a state in the first optical path, the amount of transmitted light is suppressed due to the dust, dirt, difference in thickness, etc. Therefore, even if the glass piece 6 is sodium glass. If the amount of received light is equal to or less than that of the non-sodium glass, it may be erroneously determined to be non-sodium glass. Therefore, next, a method for preventing this erroneous determination will be described.

This method uses the above-mentioned second optical path 12. In the second optical path 12, the interference filter 7 as in the first optical path 11 is not provided, and the light of the halogen lamp of the light source 1 is emitted as it is. Since the light of the halogen lamp itself is visible light, the portion of the glass piece 6 placed on the second optical path 12 is irradiated with visible light. As for the visible light transmittance, there is no difference between the sodium glass and the non-sodium glass as long as the surface of the glass piece 6 has a small degree of dirt or unevenness, or has a small thickness. Therefore, in the second optical path 12, If there is a change in the amount of received light, it is based on such a stain, unevenness, and difference in thickness of the glass surface (hereinafter, simply represented by "stain").

The relationship between the degree of "dirt" on the surface of the glass piece 6 and the amount of light received by the light flux that has been transmitted through the glass piece 6 is as follows:
For sodium glass and non-sodium glass, data is collected by irradiating a light flux or visible light with a wavelength in the infrared region and input to a personal computer of the arithmetic circuit 5 to be referred to when judging the glass piece 6. However, in the following description, the relationship between the degree of contamination of the glass piece 6 and the amount of received light is shown in the graph of FIG.

In this graph, the degree of contamination on the surface of the glass piece is shown on the horizontal axis, and the amount of received light corresponding to it is shown on the vertical axis. Then, the straight line indicates the relationship between the stain on the surface of the non-sodium glass and the amount of received light in the first optical path, and the straight line indicates the relationship between the stain on the surface of the sodium glass and the amount of received light in the first optical path. Is.

The same straight line shows the relationship between the stain on the surface of sodium glass and the amount of received light in the second optical path. In the second optical path, the glass piece is irradiated with visible light as described above. Since there is almost no difference in the transmittance of visible light between sodium glass and non-sodium glass, this straight line is also a straight line showing the relationship between the stain on the surface of non-sodium glass and the amount of received light. Both of the lines are negative and have the same slope because it is idealized that the amount of received light decreases proportionally as the dirt becomes larger.

Now, looking only at the first optical path,
As indicated by the straight line, the amount of light received by sodium glass is N when there is no stain, and is larger than the amount of received light UN of non-sodium glass when there is no stain. Until 0 becomes 0, the straight line is always above the straight line showing non-sodium glass on the graph. Therefore, while the stain is small, the amount of received light UN indicated by the broken line in FIG. 3 is set as a limit value, and a glass piece having a received amount of light larger than this value can be determined as sodium glass.

However, as the dirt becomes larger,
When the value on the horizontal axis of the straight line becomes T ₂ ^' , as shown on the vertical axis at that time, the received light amount for sodium glass is also the maximum received light amount U when the non-sodium glass is not contaminated.
When the number of stains reaches N and the amount of dirt becomes larger thereafter, the amount of light received for sodium glass becomes smaller than UN, and the determination of only the amount of light received in the first optical path may mistakenly identify sodium glass as non-sodium glass. Become.

Therefore, as shown below, the erroneous determination in the first optical path is prevented by utilizing the straight line of the second optical path.

For example, it is assumed that a glass piece is placed at the detection positions of both optical paths and the amount of light received in the first optical path is M as shown on the vertical axis in FIG. Since this is smaller than the maximum received light amount UN of the non-sodium glass, it is determined as non-sodium glass in the determination of only the received light amount in the first optical path.

However, the amount of received light is determined to be M in the first optical path because the stain is "β" due to the straight line of
"Α" by the straight line, the former corresponds to non-sodium glass and the latter corresponds to sodium glass.

At this time, looking at the amount of visible light received in the second optical path, and if it is detected as "a", the straight line of shows the degree of contamination at that time, which is "α". Therefore, the reason why the amount of received light becomes M with the stain of "α" is when the glass to be detected is sodium glass with reference to the straight line. Therefore, at this time, it is understood that the determination by the first optical path is incorrect.

On the other hand, when the amount of light received on the second optical path is detected as "b", the degree of contamination is "similarly".
β ”, and the amount of received light is M due to the contamination of“ β ”when the glass to be detected is non-sodium glass with reference to the straight line of, and at this time, the first optical path It matches the judgment result.

In this way, erroneous determination of sodium glass and non-sodium glass can be prevented in consideration of the degree of contamination of the glass piece that can be detected in the second optical path and the amount of light received in the first optical path.

However, when the stain reaches the value of T ₂ , thereafter, until the stain is T ₃ , visible light passes through the glass piece in the second optical path and the degree of stain can be detected.
_When it becomes ₂ , both the straight lines and the straight lines thereafter intersect with the horizontal axis, and the amount of received light is 0 for both sodium glass and non-sodium glass, so it is not possible to distinguish between the two. That is, the identifiable limit is the area up to T ₂ where the stain on the glass piece is shown in the graph of FIG.

In this connection, for the straight line of the second optical path, it intersects the abscissa at the position of T ₃ , which is
When the stain becomes T ₃ or more, it means that the visible light cannot pass through the glass piece and cannot be received in the second optical path, and therefore the stain itself cannot be determined.

Therefore, when determining the light projection amount of the second optical path, the straight line of the horizontal axis is so that the degree of contamination can be determined up to the level of T ₂ at which the light receiving amount of the above straight line can be detected. The position T ₃ intersecting with must be on the right side of T ₂ .

That is, it is important that the minimum value of the light projection amount of the second optical path corresponds to the light reception amount when the straight line passing through T ₂ on the horizontal axis of the graph intersects the vertical axis.

(Second Embodiment) In the second embodiment,
As shown in FIG. 4, interference filters 17 and 17 are also arranged in the second optical path 12 of the optical identification device 10 of the first embodiment. Other configurations are the same as those of the first embodiment.

The interference filter 17 has a first optical path 11
While the interference filter 7 of No. 1 transmits infrared light having a wavelength of 2800 nm, the one that transmits only infrared light having a wavelength of 1800 nm was used. Near this 1800 nm (± 5
%), The difference in the amount of transmitted light between sodium glass and non-sodium glass is small, as in the case of visible light.

Therefore, also in this embodiment in which the infrared light having the wavelength of 1800 nm is applied to the glass piece 6 of the second optical path 12, as in the case of applying visible light in the first embodiment, If there is a change in the amount of light received by the second optical path 12, it is due to stains or irregularities on the surface of the glass piece 6 and the difference in thickness. It is possible to prevent erroneous determination in.

[0052]

As described above, according to the present invention, the discrimination between sodium glass and non-sodium glass can be performed by the optical device in the same manner as the discrimination by the color difference, so that the entire discrimination device can be performed only by the optical device.

Therefore, there is an advantage that the optical components of the optical discriminating device due to the difference in shape and color can be used in common and the overall constitution of the device can be simplified.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an optical device of an embodiment.

FIG. 2A is a principle diagram of ambient light prevention, showing a state of ambient light intrusion in FIG. 2A and an interference filter for preventing ambient light intrusion in FIG.

FIG. 3 is a graph showing the relationship between the amount of light received and the stain on one glass surface.

FIG. 4 is a schematic diagram showing an optical device according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 light source 2 condensing lens 3 light receiving element 4 amplifier 5 arithmetic circuit 6 glass piece 7, 17 interference filter 11 first optical path 12 second optical path 21 light projecting section 22 light receiving section 23 ambient light

Claims (3)

[Claims] 1. A device for receiving the transmitted light of the reference light emitted from the light projecting portion onto the glass to be detected by the light receiving portion and detecting the amount of received light to identify foreign glass, wherein the reference light is visible light. 280 between the light emitter and the light receiver
An interference filter that passes only the light flux with a wavelength of 0 nm ± 5% is provided, and the light flux that has passed through the interference filter is applied to the glass to be detected, and the amount of received light is detected to distinguish between sodium glass and non-sodium glass. A different glass identification device characterized in that 2. An optical path having the interference filter is defined as a first optical path, a second optical path having no interference filter is provided in parallel with the first optical path, and the glass to be detected is arranged across both optical paths. The foreign glass identifying device according to claim 1, wherein the glass to be detected is irradiated with visible light in the second optical path. 3. An interference filter is provided in the second optical path,
The foreign glass discriminating apparatus according to claim 2, wherein the interference filter has a characteristic of transmitting only a light flux having a wavelength of 1800 nm ± 5%.