WO1986007638A1 - X-ray detection apparatus - Google Patents

X-ray detection apparatus Download PDF

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Publication number
WO1986007638A1
WO1986007638A1 PCT/GB1986/000362 GB8600362W WO8607638A1 WO 1986007638 A1 WO1986007638 A1 WO 1986007638A1 GB 8600362 W GB8600362 W GB 8600362W WO 8607638 A1 WO8607638 A1 WO 8607638A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
light guides
aperture
circular array
guides
Prior art date
Application number
PCT/GB1986/000362
Other languages
French (fr)
Inventor
Edwin George Johnson
Original Assignee
Goring Kerr Plc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Goring Kerr Plc filed Critical Goring Kerr Plc
Publication of WO1986007638A1 publication Critical patent/WO1986007638A1/en
Priority to FI870735A priority Critical patent/FI870735A/en

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/02—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material
    • G01N23/06—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption
    • G01N23/083—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption the radiation being X-rays
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/16—Measuring radiation intensity
    • G01T1/20—Measuring radiation intensity with scintillation detectors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T7/00—Details of radiation-measuring instruments
    • G01T7/08—Means for conveying samples received
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V5/00—Prospecting or detecting by the use of ionising radiation, e.g. of natural or induced radioactivity
    • G01V5/20—Detecting prohibited goods, e.g. weapons, explosives, hazardous substances, contraband or smuggled objects
    • G01V5/22—Active interrogation, i.e. by irradiating objects or goods using external radiation sources, e.g. using gamma rays or cosmic rays

Definitions

  • THE PRESENT INVENTION relates to x-ray detection apparatus and more particularly to x-ray detection apparatus suitable for use in quality control procedures, such as in the detection of impurities in food products.
  • the raw materials When products such as food are mass-produced the raw materials are delivered to the factory in bulk and are then processed by machines to create the finished food items. From time-to-time impurities are present in the raw materials or in the food items, and the raw materials and the food items must be inspected in some appropriate way so that the raw products or food items containing impurities can be rejected.
  • a linear x-ray detector is located under the conveyor belt, and typically such a detector may comprise a plurality of photo diodes, for example 480 photo diodes, each coated with an x-ray phosphor.
  • each photo diode must be provided with an individual amplifier, and the outputs of the photo diodes are multiplexed to an appropriate processor adapted to determine whether the item passing through the x-ray beam at any time contains impurities.
  • the processor may operate an appropriate ejector mechansim to eject contaminated raw material or contaminated food items.
  • Inspection apparatus of this type may be used not only with man- ufactured products such as loaves of bread, cakes, pots of yoghurt and the like, but may also be utilised to locate the presence of stones and twigs in dried beans, stones in dried peas, and pieces of walnut shell in shelled walnuts, for example.
  • a problem with the prior art arrangement is that each photo diode has a different response, and thus the apparatus must be calibrated before use. Also it is expensive to provide a large number of photo diodes each with individual amplifiers, and the multiplexing system that is required is also expensive.
  • a detector apparatus for use in detecting x-rays, said detector comprising a phosphor element, sensitive to x-radiation, a plurality of light guides, each light guide having one end thereof located to receive light emanating from the said phosphor element, the said ends of the light guides being located in a regular linear array, the other ends of said light guides being located in a circular array, rotatable means being provided adjacent the circular array for sequentially interrogating the ends of the light guides in said circular array and directing light therefrom to a single light sensitive element.
  • said phosphor element is an elongated strip of phosphor, the said light guides being arranged in a single row extending axially of said strip.
  • said light guides comprise optic fibres.
  • an apertured plate is provided, therebeing means to rotate the apertured plate about an axis passing through the centre of said circular array, the aperture in the apertured plate being coal ⁇ gned with the ends of the light guides in said circular ray so that light from the light guides can sequentially pass through the aperture, therebeing further light guide means adapted to direct light from said aperture to said light sensitive element.
  • the said further light guide means comprise a transparent 1 element having an annular face thereof aligned with the ends of the light guides in said circular array but spaced therefrom by said apertured plate, and having another end thereof in contact with or adjacent the front or inlet face of said light sensitive element.
  • said transparent element constitutes an element of transparent material of conical or "funnel" configuration.
  • the apertured plate is associated with a further light guide element, one end of which is connected to said aperture and the other end of which is adapted to direct light into the light sensitive device, said further element rotating with said aperture plate.
  • the light guides are retained in the circular array by being located in an annular element having a plurality of through-going bores adapted to receive the ends of the light guides.
  • FIGURE I is a diagrammatic perspective view of the essential parts of an apparatus incorporating a sensor in accordance with the invention, with supporting elements and x-ray shielding elements omitted,for the prupose of clarity of illustration;
  • FIGURE 2 is a partial sectional view through the sensor as shown in Figure I ;
  • FIGURE 3 is a perspective view of the structure shown in Figure 2.
  • Figure I illustrates a conveyor belt I which is adapted to advance in the direction of the arrow 2.
  • the conveyor belt I is adapted to carry raw material or other items intended for inspection.
  • An x-ray source 3 is mounted in position above the conveyor belt and a masking plate 4 is located immediately beneath the x-ray source 3, the masking plate 4 defining a narrow transverse slip 5 which permits a fan- shaped beam 6 of x-rays to pass from the x-ray source 3 towards the conveyor belt.
  • the fan shaped, beam of radiation 6 is vertical and the plane of the beam extends transversely to the direction of travel 2 of the conveyor belt I .
  • the conveyor belt is transparent to x-radiation so that the fan-shaped beam 6 can, in normal circumstances, impinge on a strip-like x-ray detector 7 located under the conveyor belt.
  • the detector will be described in more detail hereinafter.
  • the detector 7 of the present invention is located immediately beneath the conveyor belt I .
  • - consists of a strip 9, which may be of a plastics material, that extends tranversely across the conveyor belt I .
  • a layer of phosphor material 10 which is sensitive to x-ray radiation and which thus emits light when excited by x-ray radiation.
  • the phosphor strip is protected by a cover I I of an appropriate protecting material.
  • the strip 9 has a plurality of recesses 12 of relatively large diameter formed in the undersurface thereof, each recess 12 communicating with a relatively narrow diameter bore 13 which extends from the recess 12 to the top of the strip 9, that is to say to the undersurface of the phosphur layer
  • Each recess 12 and associated bore 13 are adapted to receive an end * of a optic fibre 14 which is of the same diameter as the bore 13, and which has an opaque outer sheath 15 which has a smaller diameter than the recess 1 2.
  • the sheath 15 is inserted in the recess and the space between the sheath and the wall of the recess is fil led with casting resin.
  • a plurality of optic fibres 14 are provided which are retained, by the strip 9, with their ends at evenly spaced positions along the phosphor strip 10 which extends tranversely to the direction of travel of the conveyor belt I .
  • the phosphor strip will be evenly irradiated with x-ray radiation and will glow evenly thus providing equal amounts of light to each optic fibre.
  • the intensity of light emission of the phosphor strip wil l be modulated, and thus the intensity of light passing down each optic fibre will be modulated appropriately.
  • the other ends of the optic fibres 14 are connected to a photo multiplier assembly ⁇ 6.
  • the photo multiplier assembly ⁇ 6 Includes an annular optic fibre retaining member 17. On the front face of the annular member 17 are a plurality of evenly spaced recesses 18 of a greater diameter than the outer sheath 15 on each of the optic fibres 1 . At the base of each recess 18 is a relatively narrow bore 19, of the same diameter as each optic fibre 1 , the bore 19 extending completely through the annular member 17.
  • the ends of the optic fibres 14 are located in the bores 19 with the sheaths 15 located in the recesses 18.
  • the spaces between the sheaths 15 and the recesses 18 are filled with a casting resin.
  • the optic fibres have a uniform linear configuration at one end and a uniform circular configuration at the other end.
  • a motor 20 is mounted in the centre of the annular member 17, the shaft of the motor being connected to an apertured disc or plate 21 which is located behind the annular member 17, the plate 21 being mounted for rotation in a plane which is parallel to but slightly spaced from the plane of the annular member 17.
  • the disc or plate 21 has a single aperture 22 which is positioned so that, cxs the disc rotates, the aperture 22 is sequentially co ⁇ ligned with the through going bores 19.
  • the aperture 22 passes each through going bore 19 any light passing down the fibre optic located within the respective through going passage 19 passes through the aperture in the disc.
  • the disc serves as a multiplexer which sequentially "interrogates" each of the optic fibres 14.
  • each optic fibre 14 is "interrogated” in turn in that, when the aperture 22 in the apertured plate 21 is coaligned with each through-going bore 19 light from the respective fibre optic 14 can pass through the aperture 22, into the element 23 which will serve to guide the light on to the front or input face of the photomultiplier 24.
  • ⁇ short pulse of light from each of the optic fibres 14 is sequentially introduced to the element 23 and is thus sequentially introduced to the photo multiplier 24.
  • the output of the photo multiplier 24 can be fed to any appropriate apparatus adapted to analyse the signals emanating from the photo multi ⁇ plier or adapted to create and display an image from those signals. If the apparatus analyses the signals it may be adapted to control the ejector 8.
  • the element 23 may be replaced by a single light fibre, one end of which is connected to the aperture 22 of the apertured plate 21 , the other end of which is located in such a position that light emanating therefrom is directed into the photomultiplier 24.
  • the light fibre would have to be at supported appropriately for co-rotation with the apertured plate 2 1 .

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  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Molecular Biology (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Toxicology (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geophysics (AREA)
  • Analysing Materials By The Use Of Radiation (AREA)

Abstract

In a detector apparatus using x-rays (3), a plurality of light guides (15) each have one end adjacent part of a linear phosphor strip (7). The other ends of the light guides form a circular array. Rotatable means (22) sequentially interrogate the ends of the light guides in circular array and direct light therefrom to a single light sensitive element (24).

Description

X-Ray Detection Apparatus
THE PRESENT INVENTION relates to x-ray detection apparatus and more particularly to x-ray detection apparatus suitable for use in quality control procedures, such as in the detection of impurities in food products.
When products such as food are mass-produced the raw materials are delivered to the factory in bulk and are then processed by machines to create the finished food items. From time-to-time impurities are present in the raw materials or in the food items, and the raw materials and the food items must be inspected in some appropriate way so that the raw products or food items containing impurities can be rejected.
It has been proposed to inspect raw materials or food items of this nature by passing them, for example on a conveyor belt, through a vertical downwardly directed fan-shaped beam of x-rays. A linear x-ray detector is located under the conveyor belt, and typically such a detector may comprise a plurality of photo diodes, for example 480 photo diodes, each coated with an x-ray phosphor. In such an arrangement each photo diode must be provided with an individual amplifier, and the outputs of the photo diodes are multiplexed to an appropriate processor adapted to determine whether the item passing through the x-ray beam at any time contains impurities.
The processor may operate an appropriate ejector mechansim to eject contaminated raw material or contaminated food items.
Inspection apparatus of this type may be used not only with man- ufactured products such as loaves of bread, cakes, pots of yoghurt and the like, but may also be utilised to locate the presence of stones and twigs in dried beans, stones in dried peas, and pieces of walnut shell in shelled walnuts, for example. A problem with the prior art arrangement is that each photo diode has a different response, and thus the apparatus must be calibrated before use. Also it is expensive to provide a large number of photo diodes each with individual amplifiers, and the multiplexing system that is required is also expensive.
According to one aspect of this invention there is provided a detector apparatus for use in detecting x-rays, said detector comprising a phosphor element, sensitive to x-radiation, a plurality of light guides, each light guide having one end thereof located to receive light emanating from the said phosphor element, the said ends of the light guides being located in a regular linear array, the other ends of said light guides being located in a circular array, rotatable means being provided adjacent the circular array for sequentially interrogating the ends of the light guides in said circular array and directing light therefrom to a single light sensitive element.
Preferably said phosphor element is an elongated strip of phosphor, the said light guides being arranged in a single row extending axially of said strip.
Preferably said light guides comprise optic fibres.
Conveniently an apertured plate is provided, therebeing means to rotate the apertured plate about an axis passing through the centre of said circular array, the aperture in the apertured plate being coalϊgned with the ends of the light guides in said circular ray so that light from the light guides can sequentially pass through the aperture, therebeing further light guide means adapted to direct light from said aperture to said light sensitive element. Preferably the said further light guide means comprise a transparent1 element having an annular face thereof aligned with the ends of the light guides in said circular array but spaced therefrom by said apertured plate, and having another end thereof in contact with or adjacent the front or inlet face of said light sensitive element.
Advantageously said transparent element constitutes an element of transparent material of conical or "funnel" configuration.
In another embodiment the apertured plate is associated with a further light guide element, one end of which is connected to said aperture and the other end of which is adapted to direct light into the light sensitive device, said further element rotating with said aperture plate.
Preferably the light guides are retained in the circular array by being located in an annular element having a plurality of through-going bores adapted to receive the ends of the light guides.
In order that the present invention may be more readily understood, and so that further features thereof may be appreciated, the invention wil l now be described, by way of example, with reference to the accompanying drawings in which:
FIGURE I is a diagrammatic perspective view of the essential parts of an apparatus incorporating a sensor in accordance with the invention, with supporting elements and x-ray shielding elements omitted,for the prupose of clarity of illustration;
FIGURE 2 is a partial sectional view through the sensor as shown in Figure I ;
and
FIGURE 3 is a perspective view of the structure shown in Figure 2.
Referring to the accompanying drawings Figure I illustrates a conveyor belt I which is adapted to advance in the direction of the arrow 2. The conveyor belt I is adapted to carry raw material or other items intended for inspection.
An x-ray source 3 is mounted in position above the conveyor belt and a masking plate 4 is located immediately beneath the x-ray source 3, the masking plate 4 defining a narrow transverse slip 5 which permits a fan- shaped beam 6 of x-rays to pass from the x-ray source 3 towards the conveyor belt. The fan shaped, beam of radiation 6 is vertical and the plane of the beam extends transversely to the direction of travel 2 of the conveyor belt I .
The conveyor belt is transparent to x-radiation so that the fan-shaped beam 6 can, in normal circumstances, impinge on a strip-like x-ray detector 7 located under the conveyor belt. The detector will be described in more detail hereinafter.
At a position located beyond the detector 7 in the direction of travel 2 of the conveyor belt there is an ejector schematically illustrated at 8. The ejector is adapted to eject from the conveyor belt any contaminated product or material detected by the x-ray detector. Any products not ejected from the conveyor belt by the ejector 8 remain on the conveyor belt for appropriate further packaging or processing etc.
Referring now to Figures 2 and 3 the detector 7 of the present invention is located immediately beneath the conveyor belt I . The detector
- consists of a strip 9, which may be of a plastics material, that extends tranversely across the conveyor belt I . On top of the strip 9 is a layer of phosphor material 10 which is sensitive to x-ray radiation and which thus emits light when excited by x-ray radiation. The phosphor strip is protected by a cover I I of an appropriate protecting material.
The strip 9 has a plurality of recesses 12 of relatively large diameter formed in the undersurface thereof, each recess 12 communicating with a relatively narrow diameter bore 13 which extends from the recess 12 to the top of the strip 9, that is to say to the undersurface of the phosphur layer
10.
Each recess 12 and associated bore 13 are adapted to receive an end * of a optic fibre 14 which is of the same diameter as the bore 13, and which has an opaque outer sheath 15 which has a smaller diameter than the recess 1 2. The sheath 15 is inserted in the recess and the space between the sheath and the wall of the recess is fil led with casting resin.
Thus a plurality of optic fibres 14 are provided which are retained, by the strip 9, with their ends at evenly spaced positions along the phosphor strip 10 which extends tranversely to the direction of travel of the conveyor belt I . Thus, when the x-ray source is initially activated the phosphor strip will be evenly irradiated with x-ray radiation and will glow evenly thus providing equal amounts of light to each optic fibre. However, when any items pass between the x-ray source and the detector strip 7 the intensity of light emission of the phosphor strip wil l be modulated, and thus the intensity of light passing down each optic fibre will be modulated appropriately.
The other ends of the optic fibres 14 are connected to a photo multiplier assembly \ 6. The photo multiplier assembly \ 6 Includes an annular optic fibre retaining member 17. On the front face of the annular member 17 are a plurality of evenly spaced recesses 18 of a greater diameter than the outer sheath 15 on each of the optic fibres 1 . At the base of each recess 18 is a relatively narrow bore 19, of the same diameter as each optic fibre 1 , the bore 19 extending completely through the annular member 17. The ends of the optic fibres 14 are located in the bores 19 with the sheaths 15 located in the recesses 18. The spaces between the sheaths 15 and the recesses 18 are filled with a casting resin. Thus the optic fibres have a uniform linear configuration at one end and a uniform circular configuration at the other end.
A motor 20 is mounted in the centre of the annular member 17, the shaft of the motor being connected to an apertured disc or plate 21 which is located behind the annular member 17, the plate 21 being mounted for rotation in a plane which is parallel to but slightly spaced from the plane of the annular member 17. The disc or plate 21 has a single aperture 22 which is positioned so that, cxs the disc rotates, the aperture 22 is sequentially coσligned with the through going bores 19. Thus, as the aperture 22 passes each through going bore 19 any light passing down the fibre optic located within the respective through going passage 19 passes through the aperture in the disc. Thus, effectively, the disc serves as a multiplexer which sequentially "interrogates" each of the optic fibres 14.
Located behind the apertured disc 21 is a hol low generally conical or
"funnel" shaped element 23 of transparent material such as transparent plastic or glass. The rim of the element 23 surrounding the large open mouth thereof is aligned with the through-going bores 19 in the annular member 17, but is separated therefrom by the apertured disc or plate 2 1 .
The narrow end of the element 23 is in contact with the front or inlet end of a photomυltipϋer 24, which can be of conventional design.
It is to be appreciated that as the apertured disc 21 rotates each optic fibre 14 is "interrogated" in turn in that, when the aperture 22 in the apertured plate 21 is coaligned with each through-going bore 19 light from the respective fibre optic 14 can pass through the aperture 22, into the element 23 which will serve to guide the light on to the front or input face of the photomultiplier 24. Thus, as the disc 21 completes α single revolution α short pulse of light from each of the optic fibres 14 (assuming that light is passing down all of the optic fibres 14) is sequentially introduced to the element 23 and is thus sequentially introduced to the photo multiplier 24.
The output of the photo multiplier 24 can be fed to any appropriate apparatus adapted to analyse the signals emanating from the photo multi¬ plier or adapted to create and display an image from those signals. If the apparatus analyses the signals it may be adapted to control the ejector 8.
It is envisaged that many modifications may be effected without departing from the scope of the present invention.
For example the element 23 may be replaced by a single light fibre, one end of which is connected to the aperture 22 of the apertured plate 21 , the other end of which is located in such a position that light emanating therefrom is directed into the photomultiplier 24. Of course, the light fibre would have to be at supported appropriately for co-rotation with the apertured plate 2 1 .
Whilst a photomultiplier is utilised in the described embodiment of the~present invention any appropriate light-sensing element could be .utilised provided that the light-sensor produced an electric output signal in response to receipt of light.
It is to be appreciated that, in the preferred embodiments of the invention, it is not necessary to provide a large number of amplifiers, neither is it necessary to provide a multiplexing system.

Claims

CLAIMS:
1. A detector apparatus for use in detecting x-rays, said detector comprising a phosphor element, sensitive to x-radiation, a plurality of light guides, each light guide having one end thereof located to receive light emanating from the said phosphor element, the said ends of the light guides being located in a regular linear array, the other ends of said light guides being located in a circular array, rotatable means being provided adjacent the circular array for sequentially interrogating the ends of the light guides in said circular array and directing light therefrom to a single light sensitive element.
2. An apparatus according to claim I wherein said phosphor element is an elongated strip of phosphor, the said light guides being arranged in a single row extending axially of said strip.
3. An apparatus according to any one of the preceding claims wherein said light guides comprise optic fibres.
. An apparatus according to any one of the preceding claims wherein an apertured plate is provided, therebeing means to rotate the apertured plate about an axis passing through the centre of said circular array, the aperture in the apertured plate being coaligned with the ends of the light guides in said circular ray so that light from the light guides can sequen- tially pass through the aperture, therebeing further light guide means adapted to direct light from said aperture to said light sensitive element.
5. An apparatus according to claim 4 wherein the said further light guide means comprise a transparent element having an annular face thereof aligned with the ends of the light guides in said circular array but spaced therefrom by said apertured plate, and having another end thereof in contact with or adjacent the front or inlet face of said light sensitive element.
6. • An apparatus according to claim 5 wherein said transparent element constitutes an element of transparent material of conical or "funnel" configuration.
7. An apparatus according to claim 4 wherein the apertured plate is associated with a further light guide element, one end of which is connected to said aperture and the other end of which is adapted to direct light into the light sensitive device, said further element rotating with said aperture plate.
8. An apparatus according to any one of the preceding claims wherein the light guides are retained in the circular array by being located in an annular element having a plurality of through-going bores adapted to receive the ends of the light guides.
9. An apparatus according to any one of the preceding claims wherein the light sensitive element comprises a photo-multiplier.
10. An apparatus according to any one of the preceding claims and substantially as herein described.
1 1. Any novel features or combination of features disclosed herein.
PCT/GB1986/000362 1985-06-21 1986-06-20 X-ray detection apparatus WO1986007638A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
FI870735A FI870735A (en) 1985-06-21 1987-02-20 ROENTGENSTRAOLDETEKTOR.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB08515812A GB2176888A (en) 1985-06-21 1985-06-21 Improvements in or relating to x-ray detection apparatus
GB8515812 1985-06-21

Publications (1)

Publication Number Publication Date
WO1986007638A1 true WO1986007638A1 (en) 1986-12-31

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1986/000362 WO1986007638A1 (en) 1985-06-21 1986-06-20 X-ray detection apparatus

Country Status (7)

Country Link
EP (1) EP0230443A1 (en)
JP (1) JPS63500335A (en)
AU (1) AU6132086A (en)
ES (1) ES8800433A1 (en)
FI (1) FI870735A (en)
GB (1) GB2176888A (en)
WO (1) WO1986007638A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2211931B (en) * 1987-11-02 1992-02-26 De Beers Ind Diamond Sorting apparatus
EP0358460B1 (en) * 1988-09-08 1993-12-29 De Beers Industrial Diamond Division (Proprietary) Limited Sorting apparatus

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3828190A (en) * 1969-01-17 1974-08-06 Measurex Corp Detector assembly
US4119850A (en) * 1977-04-05 1978-10-10 Abbott Laboratories Multiple sample, radioactive particle counting apparatus
US4366382A (en) * 1980-09-09 1982-12-28 Scanray Corporation X-Ray line scan system for use in baggage inspection
FR2552887A1 (en) * 1983-09-30 1985-04-05 Kernforschungsz Karlsruhe SYSTEM FOR DETECTING NEUTRONS AND / OR GAMMA RAYS

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1008337A (en) * 1963-04-10 1965-10-27 Muirhead & Co Ltd Improvements in or relating to facsimile telegraph apparatus
GB1312516A (en) * 1970-07-08 1973-04-04 Rank Organisation Ltd Fibre-optical scanning apparatus
US3800149A (en) * 1973-01-29 1974-03-26 Michael M Du Pont Electro-optical information conversion system using fiber optics
JPS5549703B2 (en) * 1975-03-25 1980-12-13
JPS6111693Y2 (en) * 1977-03-14 1986-04-12

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3828190A (en) * 1969-01-17 1974-08-06 Measurex Corp Detector assembly
US4119850A (en) * 1977-04-05 1978-10-10 Abbott Laboratories Multiple sample, radioactive particle counting apparatus
US4366382A (en) * 1980-09-09 1982-12-28 Scanray Corporation X-Ray line scan system for use in baggage inspection
US4366382B1 (en) * 1980-09-09 1996-01-23 Scanray Corp X-ray line scan system for use in baggage inspection
US4366382B2 (en) * 1980-09-09 1997-10-14 Scanray Corp X-ray line scan system for use in baggage inspection
FR2552887A1 (en) * 1983-09-30 1985-04-05 Kernforschungsz Karlsruhe SYSTEM FOR DETECTING NEUTRONS AND / OR GAMMA RAYS

Also Published As

Publication number Publication date
GB8515812D0 (en) 1985-07-24
FI870735A0 (en) 1987-02-20
EP0230443A1 (en) 1987-08-05
JPS63500335A (en) 1988-02-04
ES556907A0 (en) 1987-11-01
FI870735A (en) 1987-02-20
GB2176888A (en) 1987-01-07
ES8800433A1 (en) 1987-11-01
AU6132086A (en) 1987-01-13

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