JPH0247490Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an optical rice grain inspection device, and in particular to an optical grain inspection device that detects split grains, discolored grains, etc. mixed in rice grains, and examines their contamination rate. .

Optical grain inspection devices that electro-optically detect and sort out defective grains contained in rice grains are already known. For example, the applicant's Utility Model Application No. 56-71974, Utility Model Application No. 57-184813, Japanese Utility Model Application No. 57-121235, and Utility Model Application No. 59-12340 are described in the optical particle inspection apparatus which is the most suitable device for this purpose. is proposed.

The optical particle inspection device disclosed in Japanese Patent Application No. 57-121235 mentioned above is equipped with a transfer plate that slides on a slide table and has a large number of through-holes that are approximately the same shape as the rice grains, into which individual rice grains are inserted. The rice grain is inserted into the through hole and is configured to be transferred to the electro-optical detector along a reference axis of the rice grain in a certain direction. The electro-optical detector is composed of a light source and an electro-optical element, and is adapted to measure the amount of diffusely transmitted light through the rice grains. For this reason, this portion of the aforementioned slide table is provided with a crossed Nicol polarization filter to prevent direct light from the light source from entering the through hole of the transfer plate. Alternatively, instead of providing crossed Nicol polarization filters, the light source that illuminates the through-hole is not placed directly below the electro-optic element, but is shifted, and the through-hole that reaches directly below the electro-optic element is irradiated with an oblique light beam. The structure is taken. This prevents light rays from passing through gaps that may occur between the rice grains and the through holes and entering the electro-optical element as noise.

However, even if a crossed Nicol polarizing filter or the like is installed and a light beam from the T direction is irradiated into the through hole, the downward light beam hits the inner circumferential wall of the through hole and is reflected and becomes scattered light, which cannot be completely erased by the polarizing filter. This may enter the electro-optical element as non-existent noise.

An object of the present invention is to provide an electro-optical rice grain inspection device having a structure in which the downward light beam is not reflected by the above-mentioned through-hole and is not incident on the electro-optical element as noise.

According to the present invention, there is a transfer plate having a plurality of through holes arranged in the same shape as the rice grains that easily receive each grain of rice, and a transfer plate provided along the transfer plate to direct downward light to each rice grain in the through holes. In an electro-optical rice grain inspection device that has an electrical detection device including a light source for irradiation and an electro-optical element for measuring the amount of diffusely transmitted light through the rice grains, the inner peripheral wall surface of the through hole has a large number of matte fine irregularities or a large number of peripheries. An electro-optical rice grain inspection device is provided which is characterized in that a directional groove is provided and the inner circumferential wall surface is jagged.

The invention will be explained in detail below in the form of examples and with reference to the accompanying drawings.

With reference to FIGS. 1 and 2, the endless belt 1 is
It travels around a driven pulley 2, a drive pulley 4 driven by a motor 3, and an auxiliary pulley 5, with the driven pulley 2 at the lower end and the drive pulley 4 at the upper end arranged as an ascending running surface for sorting rice grains. Through holes 1a are provided along the running direction of the endless belt. The upward inclination angle of the running surface is preferably about 45 degrees. This through hole 1a has a vertically long shape, and is provided with its vertical axis directed toward the running direction of the endless belt 1. The shape and size of the through hole 1a are similar to that of a single grain of rice, and the size is slightly larger. When aligned along the vertical axis direction, it falls smoothly into the through hole 1a. Further, the through-holes 1a pass through the endless belt 1 from the front surface to the back surface with its cross-sectional shape macroscopically unchanged. Therefore, the inner peripheral wall surface 1b of the through hole 1a is
As will be described later, it is jagged to prevent reflected light from reaching the light receiving element. Endless belt 1
The back surface of the rice grain is arranged so that it can slide on the sliding surfaces of slide tables 6a, 6b, and 6c provided inside the conveyor loop, so that each grain of rice in the through hole 1a enters the inside of the conveyor loop. This is prevented. Furthermore, since the arrangement of rice grains in the through-hole has a very large effect on the optical detection output, it is desirable that the rice grains enter the through-hole in as uniform a state as possible. By sliding the rice grains in the through-hole on the slide table, even if the rice grains are initially unstable, they gradually become stable.

A rice grain input hopper 7 is provided at the lower end of the running surface, and the rice grains introduced here function as the bottom of the hopper 7. A guide plate 8 is provided on the lower surface of which the running surface slides. As clearly understood in FIG. 2, this guide plate 8 has a plurality of tapered grooves 8 aligned with each row of through holes 1a provided in the endless belt 1.
a is provided in a comb shape, and the minimum width of this tapered groove 8a is made almost equal to the width of one grain of rice, so the rice grains put into the hopper 5 fall into this tapered groove 8a and meet the standard. It is oriented with its axis aligned in the running direction of the running surface, that is, in the longitudinal axis direction of the through hole 1a.

A leveling device 9 is provided downstream of the input hopper 7 and carries a leaf spring 9a and a bristle brush 9b. First, the leaf spring 9a flicks off the excess rice grains, and then the end of the bristle brush 9b is applied to the endless belt 1.
By stroking the surface of the rice grains into the through-hole 1a, the rice grains are ensured to enter one by one, and the rice grains that are caught in the through-hole 1a and previously transported are simply repelled and returned to the hopper 7. Therefore, the tip of the guide plate 8 is given a rake angle and the endless belt 1 is
It is preferable that rice grains sliding down the running surface of the hopper 7 are easily returned to the hopper 7.

Further upstream, an electro-optical detector 10 is provided, which irradiates light from a light source 10a into the through-holes 1a of the endless belt 1, and detects the amount of light that passes through each rice grain with a light-receiving element 10b.

The electro-optic detector 10 will be described in detail with reference to FIG.

In FIG. 3, the slide table 6a is provided with a slot 10c so as to cross itself, and a transparent plate 10d is inserted therein so that its upper surface is flush with the sliding surface of the slide table 6a. The first polarizing plate 10e is fitted onto the lower surface of the transparent plate 10d. Further, a second polarizing plate 10f is provided directly above the endless belt 1 at a position facing the transparent plate 10d. This second polarizing plate 10
A light receiving element 10b is provided opposite to and above f. First and second polarizing plates 10e, 1
0f constitute a pair of orthogonal Nicol polarization filters. Therefore, direct light from the light source 10a is passed through the transparent plate 10d and the through hole 1a to the light receiving element 1.
Since 0b does not receive light, the light receiving element 10b
The system is designed so that only the rays that diffusely pass through each grain of rice can reach it. Note that the light receiving elements 10b are provided in the same number of rows as the through holes 1a provided in the endless belt 1, facing the rows.

The light-receiving element 10b converts the amount of light received into an electrical signal, sends this to a processing arithmetic circuit (not shown), and performs grain size adjustment and determination of defective grains. If the slide table 6a is made of a transparent glass plate or the like, the slot 10c and the transparent plate 10d become unnecessary.

After passing the drive roller 4, the endless belt 1 descends rapidly, and after passing around the auxiliary pulley 5, the surface thereof faces downward, so that the rice grains in the through holes 1a fall and are received in the receiving container 11. Note that reference number 12 is a cleaning brush device having a bristle brush 12a.

As is clear from FIG. 3, the inner circumferential wall surface 1b of the through hole 1a is provided with a large number of circumferential grooves, and the light source 10
The light rays from the inner peripheral wall surface 10a are reflected downward. This prevents the light reflected by the inner circumferential wall surface 10a from being directed toward the light receiving element 10b from the through hole 1a as noise light.

The method of forming a large number of grooves as described above in the through hole 1a having a special cross-sectional shape can be performed by various known methods such as machining, insert insertion sandblasting, chemical processing, etc., but the method of forming jagged grooves is as follows. Since this is not the main subject of this invention, its explanation will be omitted.

Although the present invention has been described above in the form of embodiments, the present invention is not limited to the above-mentioned embodiments, but can be modified in various ways within the scope of the claims for utility model registration.

For example, in the above embodiment, the transfer plate is described as an endless belt, but it may also be in the form of a disc with through holes arranged around its periphery, as described in Japanese Utility Model Application No. 71947/1983.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of an electro-optical grain inspection apparatus for rice grains, which is an embodiment of the present invention. FIG. 2 is a top view of the electro-optical inspection apparatus shown in FIG. 1; FIG. 3 is an enlarged sectional view taken along the - line in FIG. 1. 1...Endless belt, 1a...Through hole, 1b...
Inner peripheral wall surface, 2...Followed roller, 3...Motor, 4
... Drive roller, 5 ... Auxiliary roller, 6a, 6
b, 6c...Slide stand, 7...Insertion hopper, 8
... Guide plate, 8a ... Tapered groove, 9 ... Leveling device, 9a ... Leaf spring, 9b ... Bristle brush, 1
0... Electro-optical detector, 10a... Light source, 10
b... Light receiving element, 10c... Slot, 10d...
...Transparent plate, 10e, 10f...Polarizing plate (crossed Nicol polarizing filter), 11...Receiving container, 12...
Cleaning brush device, 12a... bristle brush.

Claims (1)

[Claim for Utility Model Registration] A transfer plate with a plurality of through-holes arranged in a shape almost identical to that of rice grains to easily receive each grain of rice, and a transfer plate provided along this transfer plate and arranged downwardly for each rice grain in the through-hole. In an electro-optical rice grain inspection device that has a light source that irradiates a light beam and an electric detection device that includes an electro-optical element that measures the amount of diffusely transmitted light through the rice grains, the inner peripheral wall surface of the through hole is matted, has many fine irregularities, or has many An electro-optical rice grain inspection device characterized in that a circumferential groove is provided and the inner peripheral wall surface is jagged.