Patent ID: 12235203

BEST MODE FOR CARRYING OUT THE INVENTION

The objects, specific advantages, and novel features of the present invention will become apparent from the following detailed description and preferred embodiments in conjunction with the accompanying drawings. It should be noted that in the drawings, the same components are denoted by the same reference numerals even though they are depicted in different drawings. Although such terms as “first” and “second,” etc. may be used to describe various components, these components should not be limited by above terms. These terms are used only to distinguish one component from another. In the description of the present invention, detailed explanations of related art are omitted when it is deemed that they may unnecessarily obscure the essence of the present invention.

Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG.1is a cross-sectional view of a lighting system for pellet analysis according to a first embodiment of the present invention,FIG.2is a bottom view as viewed toward the inner upper side of the casing illustrated inFIG.1, andFIG.3is a perspective view of the upper illumination assembly illustrated inFIG.1.

Referring toFIGS.1to3, the lighting system includes: a casing100having an internal space, a through-hole110formed at an upper side thereof, and inner upper and lower portions between which objects (P) to be sorted including a plurality of pellets move; upper illumination assemblies200, each of which includes a plurality of first illumination sources210irradiating first illumination light and a first light source holder220fixing the first illumination sources210onto an imaginary curved plane convexly rounded toward the objects (P) in a circular arc direction corresponding to the vertical direction with respect to the casing100such that rows of light source arrays, in which some of the plurality of first illumination sources210are arrayed along the lengthwise direction of the imaginary curved plane, are arrayed parallel to the circular arc direction of the imaginary curved plane, arranged in the inner upper portion of the casing110to irradiate the first illumination light toward upper and side portions of the objects (P); and lower illumination assemblies300, each of which includes a plurality of second illumination sources310irradiating second illumination light and a second light source holder320fixing the plurality of second illumination sources310, arranged in the inner lower portion of the casing100to irradiate the second illumination light toward lower and side portions of the objects (P).

The present invention is directed to a lighting system for pellet analysis and an apparatus for foreign matter sorting that are applied to technologies in which images of transparent and opaque pellets are acquired and the pellets are analyzed based on the images. Pellets are raw materials widely used in various fields such as films, pipes, and automotive interior materials. Even pellets produced by the same process are mixed with a number of pellets of other colors such as black, yellow, and red and pellets of other shapes such as long, twin, and snakeskin shapes. Thus, an apparatus for foreign matter sorting to sort normal pellets and abnormal foreign pellets was developed in which the pellets are imaged with a camera and a lighting system and are analyzed based on the images. However, the lighting system used in the conventional apparatus has a problem in that very various forms of shadows appear due to interactions between pellets and illumination light, making it impossible to distinguish actual foreign particles (pellets) and normal pellets only with images. The present invention has been devised to provide a solution to this problem.

As described above, the lighting system according to the first embodiment of the present invention includes a casing100, upper illumination assemblies200, and lower illumination assemblies300.

The casing100is a box-shaped member accommodating the upper illumination assemblies200and the lower illumination assemblies300and has an internal space divided into an inner upper portion and an inner lower portion. The casing100may consist of an upper casing part forming the inner upper portion and a lower casing part forming the inner lower portion. The upper and lower casing parts may be physically separated from, hingedly coupled to or integrated with each other. The casing100has a through-hole110formed at an upper side thereof. The internal space of the casing100is in communication with the outside through the through-hole. Objects (P) to be sorted as analytes move between the inner upper and lower portions of the casing100. An image sensor is arranged at a position corresponding to the through-hole110outside the casing to acquire images of the objects (P). The objects (P) are samples including a plurality of pellets and may be transported by a chute. The chute may be made of a light transmitting material.

The upper illumination assemblies200irradiate first illumination light toward upper and side portions of the objects (P). Each of the upper illumination assemblies200includes a plurality of first illumination sources210and a first light source holder220.

Each of the plurality of first illumination sources210irradiates first illumination light. The first illumination sources may be, for example, LEDs, and are not necessarily limited thereto. Any light sources that can irradiate illumination light may be used without particular limitation as the first illumination sources.

The first light source holder220fixes the plurality of first illumination sources210. The plurality of first illumination sources210are arranged on an imaginary curved plane by the first light source holder220. The imaginary curved plane is convexly rounded toward the objects (P) in a circular arc direction corresponding to the vertical direction with respect to the casing. Some of the plurality of first illumination sources210are spaced apart from each other along the lengthwise direction of the imaginary curved plane, that is, the outer circumferential direction perpendicular to the circular arc direction, to form rows of light source arrays (PAn). The first illumination sources210are arranged such that the plurality of rows of light source arrays (PA1, PA2, . . . , and PAn) are arrayed in parallel with each other along the circular arc direction (seeFIG.3). The first illumination sources210in one (PA1) of the rows of light source arrays and the first illumination sources210in another one (PA2) of the rows of light source arrays have different light intensities. That is, the light intensities of the rows of light source arrays (PA1, PA2, . . . , and PAn) may be different from each other.

The first light source holder220is arranged in the inner upper portion of the casing100such that the plurality of first illumination sources210irradiate first illumination light toward the objects (P) downward obliquely. Accordingly, the first illumination light propagates toward upper and side portions of the objects (P).

The lower illumination assemblies300irradiate second illumination light toward lower and side portions of the objects (P). Each of the lower illumination assemblies300includes a plurality of second illumination sources310and a second light source holder320.

Each of the plurality of second illumination sources310irradiates second illumination light. The second illumination sources may be, for example, LEDs, and are not necessarily limited thereto. Any light sources that can irradiate illumination light may be used without particular limitation as the second illumination sources.

The second light source holder320fixes the plurality of second illumination sources310. The second light source holder320is arranged in the inner lower portion of the casing100such that the plurality of second illumination sources310irradiate second illumination light toward the objects (P) downward obliquely. Accordingly, the second illumination light propagates toward lower and side portions of the objects (P).

Referring toFIG.2, the upper illumination assemblies200are provided in four. The upper illumination assemblies200are arranged at four sides of an imaginary rectangular ring centered on the through-hole110. The lower illumination assemblies300are provided in four. The lower illumination assemblies300are arranged to face the upper illumination assemblies200diagonally in a one-to-one relationship.

The second illumination light from the lower illumination assemblies300is irradiated toward lower portions of the pellets upward obliquely. This irradiation can block the appearance of shadows in spaces between the pellets. In addition, the first illumination light irradiated downward obliquely in all directions from the plurality of first illumination sources210arranged on the imaginary curved plane reaches not only the side portions but also the lower portions of the pellets, which can suppress the appearance of shadows. The light intensities of the first illumination sources210and the second illumination sources310may also be differentiated uniformly or individually to control the appearance of shadows due to interactions between the pellets and the illumination light.

The coupling between the first illumination sources210and the first light source holder220can be implemented in various ways. For example, the first light source holder220aof the upper illumination assembly200amay include an illumination mounting plane221formed in a shape corresponding to the imaginary curved plane and the plurality of first illumination sources210may be arranged in parallel with each other on the illumination mounting plane221to configure the rows of light source arrays (PA1, PA2, . . . , and PAn), as illustrated inFIG.3. The coupling between the first illumination sources210and the first light source holder220may be implemented in other ways, which will be described with reference to the following other embodiments.

FIG.4is a cross-sectional view of a lighting system for pellet analysis according to a second embodiment of the present invention. As illustrated inFIG.4, the lighting system includes upper illumination assemblies200b. Each of the upper illumination assemblies200bincludes a rotatable cylindrical first light source holder220b.

The outer circumference of the cylindrical first light source holder220bcorresponds to the imaginary curved plane. The plurality of first light source holder220bare arrayed in parallel with each other on the outer circumference of the cylindrical first light source holder220bto configure a plurality of rows of light source arrays (RA). The cylindrical first light source holder220bfixes the plurality of rows of light source arrays (RA).

The first light source holder220bmay rotate along a circular arc direction. The plurality of rows of light source arrays (RA) also rotate with the rotation of the first light source holder220b. Depending on the rotation angle, a selection is made as to which of the first illumination sources210irradiate first illumination light. The selected first illumination sources210are located at positions where the first illumination light can be irradiated downward obliquely onto objects (P) to be sorted.

Each of the upper illumination assemblies200aof the lighting system may further include a housing290.

The housing290is a member accommodating the first light source holder220btherein and has an opening291at a position facing the underlying objects (P) obliquely. Accordingly, the plurality of rows of light source arrays (RA) arranged on the outer circumference of the first light source holder220bare surrounded by the inner surface of the housing290and the rotation of the first light source holder220bexposes at least two adjacent ones of the rows of light source arrays (RA) to the outside through the opening291. A collection of rows of light source arrays (RA) that can be exposed through the opening291is defined as a “light irradiation zone”. That is, the plurality of rows of light source arrays (RA) are divided into a plurality of light irradiation zones (LZ1, LZ2). The light irradiation zone (LZ1) exposed through the opening291irradiates first illumination light. The first illumination sources210arranged in the different light irradiation zones (LZ1, LZ2) may have different light intensities. Accordingly, as the first light source holder220brotates, the different light irradiation zones (LZ1, LZ2) are exposed so that the first illumination sources210with different intensities can selectively irradiate light.

The lighting system may further include upper illumination rotating units400, each of which rotates the corresponding upper illumination assembly200b.

Each of the upper illumination rotating units includes a coupling shaft410and a rotary motor430. The coupling shaft410is a shaft member that couples the housing290to an inner upper side of a casing100. The coupling shaft410may be arranged perpendicular or oblique to a rotary shaft of the housing290. The rotary motor430rotates the housing290about the coupling shaft410. Accordingly, the rotation of the upper illumination assembly200bby the upper illumination rotating unit400changes the direction of light irradiated from the first illumination sources210.

FIGS.5and6are cross-sectional views of a lighting system for pellet analysis according to a third embodiment of the present invention.

Referring toFIGS.5and6, the lighting system includes upper illumination assemblies200c, each of which includes a plurality of first light source holders220c. The plurality of first light source holders220ccan fix rows of light source arrays (RA) in a one-to-one relationship. The plurality of rows of light source arrays (RA) are arranged in parallel with each other. The first light source holders220care provided as many as the number of the rows of light source arrays (RA) such that each of the rows of light source arrays (RA) is coupled to the corresponding first light source holder220c.

Each of the upper illumination assemblies200cmay further include a plurality of light source holder supports230, a first hinge shaft240, second hinge shafts250, a light source holder support length adjusting unit260, a light source holder support pivoting unit270, and a light source holder pivoting unit280.

Each of the plurality of light source holder supports230includes a cylinder231and a piston233. One end of the piston233is inserted into one end of the cylinder231. The piston233reciprocates in the cylinder231. Accordingly, the length of the light source holder support230varies depending on the length of the piston233inserted. The other end of the piston233exposed outside the cylinder231is coupled to the corresponding first light source holder220c. As a result, the plurality of rows of light source arrays (RA), the first light source holders220c, and the light source holder supports230are coupled to one another one by one.

The first hinge shaft240penetrates the other ends of the cylinders231of the plurality of light source holder supports230to integrally connect the plurality of light source holder supports230. This integral connection allows the plurality of light source holder supports230to pivot in the vertical direction with respect to a casing100around the first hinge shaft240.

Each of the second hinge shafts250hingedly couples the other end of the piston233of the light source holder support230and the first light source holder220csuch that the first light source holder220cis pivoted. The second hinge shafts250are arrayed in parallel with the first hinge shaft240. With this array, the second hinge shafts250are pivoted in a plane identical to or facing the plane where the light source holder supports230are pivoted.

The light source holder support length adjusting unit260controls the lengths of the plurality of light source holder supports230individually. The light source holder support length adjusting unit260controls the reciprocal movement of the piston233of each of the light source holder supports230to adjust the length of the piston233inserted into the corresponding cylinder231, with the result that the length of the light source holder support230is adjusted. For example, the light source holder support length adjusting unit260may control the amount and inflow position of a hydraulic fluid supplied to the cylinder231to adjust the length of the piston233inserted but is not necessarily limited to this function.

The light source holder support pivoting unit270pivots the plurality of light source holder supports230individually. For example, rotary devices such as motors may be individually mounted in the plurality of light source holder supports230and the light source holder support pivoting unit270may control the rotary devices to rotate the light source holder supports230. However, the light source holder support pivoting unit270is not necessarily limited to this function as long as it can pivot the plurality of light source holder supports230individually.

The light source holder pivoting unit280pivots the plurality of first light source holders220cindividually. For example, rotary devices such as motors may be individually mounted in the plurality of first light source holders220cand the light source holder pivoting unit280may control the rotary devices to rotate the first light source holders220c. However, the light source holder pivoting unit280is not necessarily limited to this function as long as it can pivot the plurality of first light source holders220cindividually.

Each of the upper illumination assemblies200cof the lighting system may further include a housing290. The housing290accommodates the plurality of first light source holders220cand the light source holder supports230therein and has an opening291at a position facing underlying objects (P) to be sorted obliquely. Accordingly, the plurality of rows of light source arrays (RA) are surrounded by the inner surface of the housing290and the rotation of at least two ones of the plurality of light source holder supports230exposes at least two adjacent ones of the rows of light source arrays (RA) connected to the rotating light source holder supports230to the outside through the opening291. A collection of rows of light source arrays (RA) that can be exposed through the opening291is defined as a “light irradiation zone”. That is, the plurality of rows of light source arrays (RA) are divided into a plurality of light irradiation zones (LZ1, LZ2). The light irradiation zone (LZ1) exposed through the opening291irradiates first illumination light. The first illumination sources210arranged in the different light irradiation zones (LZ1, LZ2) may have different light intensities. Accordingly, as the light source holder supports230rotates, the different light irradiation zones (LZ1, LZ2) are exposed so that the first illumination sources210with different light intensities can selectively irradiate light. Since the first light source holders220care also pivoted individually in the light irradiation zones (LZ1, LZ2), the rows of light source arrays (RA) exposed through the opening291are moved when the light source holder supports230are pivoted, enabling control over the direction of the first illumination light.

The lighting system may further include upper illumination rotating units400, each of which rotates the corresponding upper illumination assembly200c.

Each of the upper illumination rotating units400may include a coupling shaft410and a rotary motor430. The coupling shaft410is a shaft member that couples the housing290to an inner upper side of the casing100. The coupling shaft410may be arranged perpendicular or oblique to a rotary shaft of the housing290. The rotary motor430rotates the housing290about the coupling shaft410. Accordingly, the rotation of the upper illumination assembly200cby the upper illumination rotating unit400changes the direction of light irradiated from the first illumination sources210to a direction perpendicular to the pivoting direction of the light source holder supports230.

A description will be given of an apparatus for foreign matter sorting to which any of the lighting systems for pellet analysis according to the first to third embodiments of the present invention is applied. The lighting systems for pellet analysis have been described above and a repeated explanation is omitted or simplified.

FIG.7is a cross-sectional view of an apparatus for foreign matter sorting according to an embodiment of the present invention. With reference to this figure, the apparatus includes a lighting system1000for pellet analysis, a chute2000, an image sensor3000, and a compressed air spraying unit4000.

The lighting system1000is any of the lighting systems according to the first to third embodiments of the present invention. That is, the lighting system1000is designed in which the upper illumination assemblies200,200a,200bor200care arranged in the inner upper portion of the casing100to irradiate first illumination light downward obliquely and the lower illumination assemblies300are arranged in the inner lower portion of the casing100to irradiate second illumination light upward obliquely.

The chute2000is a moving means for moving objects (P) to be sorted including a plurality of pellets. The chute2000is arranged in the casing100to move the objects (P) between the inner upper and lower portions of the casing100. The objects (P) pass through a zone irradiated with the first illumination light and the second illumination light. The chute2000may be made of a material through which the second illumination light can pass.

The image sensor3000images the objects (P) under the first illumination light and the second illumination light through the through-hole110formed at an upper side of the casing100. The image sensor3000may be a CCD sensor but is not necessarily limited thereto.

The compressed air spraying unit4000is a device for spraying compressed air upward from the bottom of the chute2000. Air nozzles2100are disposed so as to penetrate from the bottom to the top of the chute. Compressed air flows upward through the air nozzles2100to allow the objects (P) moving along the upper surface of the chute2000to float from the surface of the chute2000. At this time, the first illumination light and the second illumination light can reach the lower portions of the objects (P), which enables analysis of the pellets while suppressing the appearance of shadows.

Overall, the lighting system of the present invention is designed in which a plurality of illumination devices are arrayed such that the arrays are convexly rounded toward objects (P) to be sorted including a plurality of pellets and moving in one direction and irradiate illumination light in all directions, including upward, downward, left, and right directions, avoiding the appearance of shadows due to interactions between the objects (P) and the illumination light. In addition, all or some of the plurality of illumination devices have different light intensities and irradiate light in controlled directions. Therefore, control over the light intensities depending on the shape of objects (P) to be sorted suppresses the appearance of shadows regardless of the shape of the objects (P).

Although the present invention has been described herein with reference to the foregoing specific embodiments, these embodiments do not serve to limit the invention and are set forth for illustrative purposes. It will be apparent to those skilled in the art that modifications and improvements can be made without departing from the spirit and scope of the invention.

Simple modifications and changes of the present invention belong to the scope of the present invention and the specific scope of the present invention will be clearly defined by the appended claims.

[Explanation of Reference Numerals]100: Casing110: Through-hole200: Upper illumination assembly210: First illumination source220: First light source holder221: Illumination mounting plane230: Light source holder support231: Cylinder233: Piston240: First hinge shaft250: Second hinge shaft260: Light source holder support length adjusting unit270: Light source holder support pivoting unit280: Light source holder pivoting unit290: Housing291: Opening300: Lower illumination assembly310: Second illumination source320: Second light source holder400: Upper illumination rotating unit410: Coupling shaft430: Rotary motor1000: Lighting system for pellet analysis2000: Chute3000: Image sensor4000: Compressed air spraying unitP: Object to be sorted

INDUSTRIAL APPLICABILITY

The lighting system of the present invention is designed in which a plurality of illumination devices are arrayed such that the arrays are convexly rounded toward objects to be sorted including a plurality of pellets and moving in one direction and irradiate illumination light in all directions, including upward, downward, left, and right directions, avoiding the appearance of shadows due to interactions between the objects and the illumination light. In addition, all or some of the plurality of illumination devices have different light intensities and irradiate light in controlled directions. Therefore, control over the light intensities depending on the shape of objects to be sorted suppresses the appearance of shadows regardless of the shape of the objects. Therefore, the lighting system of the present invention is suitable for industrial applications, including foreign matter sorting and analysis.