JPH0245515B2 - KOTAKUSENBETSUSOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gloss sorting device for optically sorting objects to be sorted by projecting light onto them.

2. Description of the Related Art There is a conventionally known method of sorting articles by projecting light onto articles to be sorted and comparing the amount of reflected light with the amount of light serving as a sorting standard.
For example, in order to sort out granular materials such as grains, light is projected onto the granular materials that continuously flow down from a predetermined guide, and the reflected light of this projected light is detected by a sensor and compared with a reference value. There are ways to perform selection.

Furthermore, for spherical objects such as pearls, a patent application filed by the same applicant and inventor as the present application entitled "Spherical Object Sorting Apparatus" (Japanese Patent Application No. 58-247325 ~ As disclosed in Japanese Patent No. 60-137477~), there is a sorting method that uses a structure that rotates the objects to be sorted while being conveyed by a guide and projects light around the entire circumference in order to improve the accuracy of sorting. . In this sorting method as well, light is projected from a normal light source and the reflected light is detected by a sensor.

In such a conventional method, a sensor receives all the reflected light from a surface onto which light is projected onto the object to be sorted, and detects the amount of light. In other words, the amount of light is the integrated amount of reflected light from the entire light-reflecting surface of the object to be sorted. For this reason, even if there are areas with different effects in one subdivided area of the light-reflecting surface, it is difficult to separate them because the overall amount of light is compared, and it has been desired to improve the selection accuracy.

Therefore, an object of the present invention is to provide a novel gloss sorting device with improved sorting accuracy.

The inventor obtained the following findings by projecting a linear light source onto the object to be sorted and using a sensor to detect only the linear high-luminance area on the surface of the object to be sorted. . That is, near the center of the sensor signal, reflected light from the object to be sorted is dominant, while scattered light is dominant at the base of the waveform. The amount of reflected light and scattered light varies depending on the level of gloss on the surface of the object to be sorted. Therefore, it has been found that the surface gloss of the object to be sorted can be sorted by waveform processing the sensor signal.
Here, the term "linear light source" includes all light sources that have the function of converging and projecting light from the light source in a straight line onto the object to be sorted.For example, a cylindrical light source such as a line filament lamp Of course, there are tubes in which a long filament is stretched in a line so that the filament itself projects in a straight line, as well as fluorescent or incandescent lamps that have a narrow projection slit in the front. It may be provided with a light shielding plate to allow linear light to pass through the slit portion. In addition, when the light source is an incandescent lamp, it is desirable to contact the slit surface with something that has the property of scattering light, such as a milky white synthetic resin thin plate.

A brief overview of typical inventions disclosed in this application is as follows.

In other words, a linear light source that projects light onto the objects to be sorted as they are sequentially conveyed is arranged perpendicular to the direction of conveyance, and the surface of the objects to be sorted is irradiated with linear high-intensity light by this linear light source. Only the area is focused by a light shielding plate with a slit and a lens, and detected by an optical sensor. By processing the output of the optical sensor into a waveform, differences in gloss are detected and the objects to be sorted are sorted. Since the conveyance direction of the object to be sorted is perpendicular to the linear high-intensity portion, it is equivalent to sequentially linearly scanning the object to be sorted in the direction opposite to the conveyance direction. Therefore, a dramatic improvement in sorting accuracy is achieved.

An embodiment of the gloss sorting device of the present invention will be described below with reference to FIGS. 1 to 4.

In FIG. 1, reference numeral 1 indicates an object to be sorted. The objects to be sorted are, for example, spherical objects such as pearls, cylindrical objects such as metal pellets, etc., and a conveying device (not shown) is used.
The materials are continuously conveyed for sorting in the direction of the arrow in the figure. This conveying device can use the base, circular rotary disk, etc. disclosed in the above-mentioned patent application "Spherical Object Sorting Apparatus".

Reference numeral 2 indicates a linear light source. This linear light source 2 is disposed on the conveyance device and projects light onto the surface of the object 1 to be sorted. The projected light is converged as reflected light and scattered light onto a photosensor 4 via an optical lens system 3, which is shown as one lens in the embodiment. The electrical output of this optical sensor 4 is input to a signal processing circuit 5, and after being subjected to predetermined processing, is output as a determination signal. Based on this judgment output, an ejector (not shown) is operated to selectively remove the objects to be sorted. For the operation of the ejector, a known forced evacuation method using jetting of compressed air can be used.

The linear light source 2 is arranged such that the length direction of the filament 21 thereof is perpendicular to the conveyance direction of the objects 1 to be sorted. Therefore, the light from the filament 21 of the linear light source 2 creates a relatively high-intensity linear irradiation area on the surface of the object to be sorted 1 perpendicular to the conveying direction. A light shielding plate 6 is interposed between the lens of the optical lens system 3 and the optical sensor 4 in order to selectively detect this high brightness area. This light shielding plate 6 has a slit 61 opened therein. The width and length of the slit 61 are set appropriately so that the optical sensor 4 can selectively detect a high-intensity area irradiated onto the object 1 to be sorted. Figure 2 shows
This is a diagram showing the planar positional relationship among the linear light source 2, the object to be sorted 1, and the light shielding plate 6, in which only the portion corresponding to the linear high-intensity portion perpendicular to the conveyance direction is shown through the slit 61. It can be seen that the light is detected by the optical sensor 4.

By the way, as a waveform of the object to be sorted during transportation detected by this optical sensor 4, a waveform as shown in FIG. 4a is obtained. Near the center of these signal waveforms, reflected light is predominant, and at the bottom of the waveform, scattered light is predominant. When the light selection is small, as shown in the waveform on the left side of FIG. 4a, there is less reflection and more scattering. In other words, the contrast of the shadow of the linear light source cast on the object to be sorted is small. On the other hand, when the gloss is high, as shown in the waveform on the right side of FIG. 4a, there is a lot of reflection and little scattering. In other words, the contrast of the shadow of the linear light source cast on the object to be sorted is large.

A determination signal for detecting the difference in gloss from the output of the optical sensor 4 and operating the ejector is obtained from the waveform processing circuit 5. This signal processing circuit 5 includes an amplifier 51 that amplifies the output of the optical sensor 4, a differentiation circuit 52 that differentiates the output from the amplifier 51, and a peak-to-peak circuit 53 that holds the peak value of the differential waveform. The comparator 54 compares the values and outputs a judgment signal depending on the magnitude thereof.

The functions and effects of the gloss sorting device having the above configuration will be explained next.

When the object 1 to be sorted, which is sequentially conveyed on the conveying device, reaches a predetermined position by light from the linear light source 2, a linear high-intensity portion appears and the surface thereof is illuminated. Only the light from this high brightness area is selectively detected by the optical sensor 4 through the slit 61 of the light shielding plate 6. If the surface of the object 1 to be sorted has low gloss, the waveform will be on the left in FIG.
Therefore, by amplifying these waveforms by the amplifier 51 and then processing them by the differentiating circuit 52 and the peak-to-peak circuit 53, the waveforms with low gloss and gentle waves have small amplitudes, and the waveforms with high gloss and steepness have small amplitudes. Large amplitude. Therefore, a discrimination signal can be obtained by comparing these amplitudes with a reference level set in advance for selection using the comparator 54. Thereafter, the ejector is driven by this discrimination signal to carry out sorting and elimination.

In this way, only the linear high-luminance area on the surface of the object to be sorted that is irradiated by the linear light source is selectively detected by the slit of the light shielding plate, and the waveform of the detected output waveform is Since the sorting is performed through processing, highly accurate sorting can be performed.
In addition, since the linear light source is arranged perpendicular to the conveyance direction of the objects to be sorted, it has the same effect as continuous linear scanning of the surface of the objects to be sorted, allowing for high-precision sorting. It has various effects such as being able to obtain a device.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention. Fig. 1 is a diagram showing the configuration of the gloss sorting device of the invention, and Fig. 2 is a plan view of the linear light source, the object to be sorted, and the light shielding plate shown in Fig. 1. FIG. 3 is a block diagram showing the configuration of the waveform processing circuit of FIG. 1, and FIG. 4 is a diagram showing waveforms processed by the waveform processing circuit. DESCRIPTION OF SYMBOLS 1... Object to be sorted, 2... Linear light source, 21... Filament, 3... Optical lens system, 4... Optical sensor, 5... Waveform processing circuit, 6... Light shielding plate, 61... Slit.

Claims (1)

[Claims] 1. A light source that projects onto the objects to be sorted that are sequentially transported for sorting is a light source that can project linearly, and this light source is arranged so that the linear projection is perpendicular to the conveyance direction of the objects to be sorted, Furthermore, an optical lens system that receives light from the object to be sorted and focuses it on an optical sensor is provided, and slits are provided corresponding to linear high-intensity areas on the surface of the object to be sorted that are created by the linear light source. inserting a light shielding plate into the optical lens system, electrically processing the output signal of the optical sensor, and comparing the processed signal with a reference value to sort the objects to be sorted; A gloss sorting device featuring: