JPS63500335A - X-ray detection device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Name: X-ray detection device The present invention relates to an X-ray detection device, particularly for quality control work such as detection of impurities in food. The present invention relates to an X-ray detection device suitable for use in

When a product such as food is mass-produced, raw materials are supplied to the factory in bulk, The food is then processed by machines and becomes a finished food. Ingredients or foods are In most cases, impurities are present and the raw materials and food products are rejected. must be tested in an appropriate manner to ensure that

Such raw materials or foodstuffs are placed, for example, on a conveyor belt and oriented vertically. It has been proposed to perform inspection by passing fan-shaped X-rays. Conveyor A linear X-ray detector is placed below the belt, and a typical example of such a detector is For example, with multiple photodiodes, such as 480 photodiodes, each is coated with X-ray phosphorus. In such a configuration , each photodiode must be individually equipped with an amplifier, and the photodiode The output of the ode determines whether what passes through the x-ray beam contains impurities or not. Sometimes it is multiplexed to the appropriate processor to decide.

This type of inspection equipment is used to inspect processed foods such as bread pieces, cakes, yogurt pots, etc. It can be used not only for industrial products, but also for example, stones and twigs in dried beans, and dried beans. It can be helpful to find stones inside the shell, strips of walnut meat inside the shelled walnuts, etc. Wear.

The problem with the prior art is that each photodiode has a different response and Thus, the device must be calibrated before use. Also, a large number of Providing separate amplifiers for each photodiode is expensive and requires Multipress equipment is also expensive.

According to one aspect of the invention, a detection device used for X-ray detection is provided. and the detector includes a phosphorus-based element sensitive to X-rays, each light guide emitting from the phosphor-based element. one end positioned to receive the light and positioned in a regular linear array; a plurality of light guides having opposite ends located in a row; and an end of the annular array of light guides; sequentially interrogates the light from which it directs light to a single light-sensitive element. and rotation means provided adjacent to the annular array.

, said phosphorous-based element is preferably a long strip of phosphorous, and said light guide is The strips are arranged in a single row extending in the axial direction of the strip.

The light guide is preferably an optical fiber.

Preferably, a perforated plate is provided, wherein the perforated plate There is a means for rotating about an axis passing through the center of the array such that the holes in the perforated plate coincides with the end of the light guide in the annular array, so that the light from the light guide other light suitable for sequentially passing through the aperture and transmitting light from said aperture to said light-sensing element; Guide means are provided.

Preferably, said further light guide means mate with an end of said annular array of light guides. an annular surface spaced from the end by the perforated plate; a transparent element having a front surface of the knowledge element or the other end abutting or proximate to the inlet surface; It will be.

Preferably, said transparent element is conical or "funnel-shaped."

In other embodiments, the perforated plate is associated with another light guide element and the perforated plate is associated with another light guide element. one end communicates with the aperture, the other end transmits light to a light sensing device, and the other element communicates with the aperture. Rotates together with the plate.

Preferably, the light guide includes an annular element having a plurality of through holes for receiving the ends of the light guide. By virtue of their prime position, they are held in a circular arrangement.

In order to make the invention easier to understand and, as a result, to appreciate its features. DESCRIPTION OF THE PREFERRED EMBODIMENTS For the purpose of understanding the invention, the present invention will be described by way of example with reference to the accompanying drawings. on the drawing In order to simplify the illustration, Fig. 1 shows this model without the supporting member and the X-ray shielding member. Figure 2 is a schematic perspective view of the essential parts of the device comprising a sensor according to the invention; The figure is a cross-sectional view of the sensor part shown in Figure 1: and FIG. 3 is a perspective view of the structure shown in FIG. 2.

Referring to the accompanying drawings, FIG. 1 shows a conveyor belt 1 traveling in the direction of arrow 2. show. The conveyor belt 1 is adapted to carry raw materials or other objects to be inspected. ing.

The XIi source 3 is located directly above the conveyor belt, and the masking plate is located directly below the X-ray source 3. Port 4 is located. The masking plate 4 has a thin slit 5, and the slit A fan-shaped X-ray beam 6 is projected from the X-ray source 3 onto the conveyor belt via the conveyor belt. fan The shaped radiation beam 6 is vertical and the plane of the beam is parallel to the conveyor belt. It is perpendicular to the traveling direction 2 of the vehicle 1.

The conveyor belt is transparent to X-rays, and the fan-shaped beam 6 is normally , corresponds to the strip-shaped X-ray detector 7 located below the conveyor belt. The examination The detector will be described later.

At a position beyond the detector 7 in the traveling direction 2 of the conveyor belt, there is a There is a diagrammatically shown ejector.

The discharger discharges contaminated product or contaminated material detected by the X-ray detector. Discharge from bare belt. Products that are not discharged from the conveyor belt by the discharger 8 are left on the conveyor belt for further packaging, processing, etc.

Referring to FIGS. 2 and 3, the detector 7 of the present invention is located directly below the conveyor belt 1. To position. The detector is made of plastic material and extends across the conveyor belt 1. It consists of strips 9. At the top of the strip 9 there is a phosphorous substance sensitive to X-ray radiation. There is a layer 10 of quality, which is excited by X-ray radiation to emit light. Phosphorous strip The pool is protected by a cover 11 of suitable insulating material.

The strip 9 has a plurality of relatively large diameter recesses 12 formed on its lower surface, and each The recess extends from the recess 12 to the top of the strip 9, i.e. to the bottom surface of the phosphorous layer 10. It communicates with a hole 13 having a relatively small diameter.

Each recess 12 and associated hole 13 are adapted to receive an optical fiber 14 having the same diameter as the hole 13. The fiber has an opaque outer sheath 15 with a smaller diameter than the recess 12. There is. The sheath 15 is inserted into the recess, and the gap between the sheath and the wall of the recess is filled with resin. be done.

Thus, the ends of the plurality of optical fibers 14 held by the strut 9 are , at equal intervals along the phosphorous strip 10 transverse to the direction of travel of the conveyor belt 1. Placed. Thus, when the xmm is activated, the phosphorous strip is uniformly exposed to x-ray radiation. etc., emitting light evenly, thus giving each optical fiber a uniform amount of light. . However, if something passes between the X-ray source and the detection strip 7, In this case, the luminous intensity of the phosphorous strip is modulated, thus passing through each optical fiber. The intensity of the emitted light is suitably modulated.

The other end of the optical fiber 14 is connected to a multiplier phototube device 16 .

The multiplier photocell arrangement @16 includes an annular member 17 that holds the optical fiber. annular part On the front surface of the material 17, recesses 1 having a larger diameter than the outer sheath 15 of each optical fiber 14 are formed at regular intervals. 8 are provided. At the bottom of each recess 18 there is a There is a hole 19 of relatively narrow diameter, which extends completely through the annular member 17.

The end of the optical fiber 14 is located in the hole 19 with the sheath 15 located in the recess 18 . The gap between the sheath 15 and the recess 18 is filled with resin. Thus, optical fiber The bar has a uniform straight profile at one end and a uniform annular profile at the other end. has.

The motor 20 is placed at the center of the annular member 17, and the motor shaft is attached to the annular member 17. with a perforated disc or plate 21 located behind the rotates in a plane parallel to the plane of the annular member 17 and slightly away from the plane. It is provided. The disk or plate 21 has a single hole 22, which As the disk rotates, the holes 22 sequentially align with the through holes 19. mosquito Thus, since the hole 22 passes through each through hole 19, it is positioned within each through hole 19. The light passing through the optical fiber placed in the disk passes through the hole in the disk. Thus, dis The block sequentially interrogates each optical fiber 14. Functions as a chibrexer.

Behind the perforated disc 21 is a transparent material such as transparent plastic or glass. A hollow, generally conical or “°funnel” shaped member 23 is disposed. Ru.

The rim of the member 23 surrounding the large mouth is aligned with the through hole 19 of the annular member 17. , separated from the through-hole by a perforated disk or plate 21 .

The narrow end of the component 3 is connected to a perforated disk 21 of conventional construction as it rotates. Then, each optical fiber 14 is sequentially "interrogated" and connected to the perforated plate 2. When the hole 22 of 1 matches each through hole 19, light from each optical fiber 14 passes through the hole 22 and enters the member 23, which directs the light to the front end face of the multiplier phototube 24. Or guide you to the entrance side. Thus, when the disk 21 rotates once, each optical fiber bar 14 short pulse of light (assuming the light passes through all optical fibers 14) ) are sequentially introduced into the member 23 and thus the multiplier photocell 24 Introduced to Kenshal.

Appropriate equipment to analyze the detected signals or to create and display images from these signals. the appropriate equipment as indicated.

Any device that analyzes signals is suitable for controlling the ejector 8.

It is emphasized that many modifications can be made without departing from the scope of the invention.

For example, member 23 could be replaced with a single optical fiber, one end of which could be Connected to the hole 22 of the perforated plate 21, the light emitted from the other end is connected to the multiplier phototube 2. Place it in a position that roughly divides it into 4 parts. Of course, the optical fiber is connected to the perforated plate 21. They must be properly supported so that they can rotate together.

Although multiplier photocells are used in the described embodiments of the invention, suitable A light sensing member is also a light sensor that generates an electrical output signal in response to light reception. If so, you can use it.

In a preferred embodiment of the invention, a number of amplifiers are also included in the multiplex system. It should also be appreciated that it is not necessary.

international search report ANNEXTτ)! E INTERNATION An, 5EARCHREPO RT　NINTERNATIONAL　APPLICATION　No, P CT/GB 86100362 (3A 13772) US-A-436638 228/12/82 NoneUS-A-411985010/10/78 N on.

US-A-382819006108/74 None

Claims (11)

[Claims] 1. A detector for detecting X-rays includes a phosphorous element sensitive to X-rays, and each light guide one end positioned to receive light emitted from the element and positioned in a regular linear array; a plurality of light guides having opposite ends positioned in an annular array; and said annular array of light guides. sequentially interrogates the ends of the wire and connects the light from there to a single light-sensitive element. used for X-ray detection, consisting of an annular array directed toward the element and a rotating means provided in close proximity to the detection device. 2. the phosphorous element is a long strip of phosphorous, and the light guide is a long strip of phosphorous; Device according to claim 1, arranged in a single axially extending row. 3. An arrangement according to any one of the preceding claims, wherein the light guide is an optical fiber. Place. 4. A perforated plate is provided, wherein the perforated plate is located within said annular array. There is a means for rotating the perforated plate about an axis passing through the core such that the holes in the perforated plate are arranged in said annular array. coincides with the end of the light guide at , so that the light from the light guide is sequential another light guide means suitable for transmitting light through the hole in the hole and from the hole to the light-sensing element; A device according to any one of the preceding claims, wherein a step is provided. 5. said further light guide means mate with an end of said annular array of light guides; an annular surface spaced from the end by a perforated plate; and an annular surface of the light sensing element. a transparent element having a front end or other end abutting or proximate to the entrance surface; Apparatus according to scope 4 of the request. 6. A transparent material element in which said transparent element is conical or “funnel” shaped. 6. A device according to claim 5 constituting an element. 7. a perforated plate is associated with another light guide element, one end of which communicates with the hole; the other end transmits light to a light sensing device, and said other element rotates with said perforated plate. A device according to claim 4. 8. The light guide is located in an annular element having a plurality of through holes that receive the ends of the light guide. Any one of the boxed boxes of said claims held in a circular array by device by. 9. A device according to any one of the preceding claims, wherein the light sensitive element is a multiplier phototube. 10. in accordance with any one of the box boxes in the foregoing claims and substantially as described herein. Place. 11. Novel features and combinations described herein.