JP2007225868A - Light reflective plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for preventing the deformation of a light reflective plate, which is obtained by fabricating a light reflective plate material into a three-dimensional shape, and reducing the fabrication cost. <P>SOLUTION: A molded piece 10 having a bottom part 12 and inclined parts 14, which are formed successively at both ends of the bottom part in the width direction and extend obliquely upward, is manufactured by using the light reflective plate material. The light reflective plate 20 is formed by arranging the plurality of molded pieces in parallel so that the upper end of each inclined part of one of the adjacent molded pieces is abutted on that of each inclined part of the other of the adjacent molded pieces. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a three-dimensional light reflecting plate for efficiently emitting light by making backlights and lighting boxes of liquid crystal display devices, electric signboards, lighting fixtures, and the like brighter and thinner.

  Conventionally, a light reflecting plate obtained by processing a plastic light reflecting sheet into a three-dimensional shape has been proposed as a light reflecting plate used in a liquid crystal display device, an electric signboard, a lighting fixture, and the like (for example, Patent Document 1). reference).

JP 2002-122863 A

  The light reflection plate obtained by processing the above-described plastic light reflection sheet into a three-dimensional shape is deformed after fabrication due to distortion during molding or shrinkage after molding. Therefore, as a means for preventing the deformation of the light reflecting plate, a hole or slit cutting portion is provided in the light reflecting plate, a claw-like bent portion is formed in the metal casing, and a metal is formed in the hole or slit cutting portion of the light reflecting plate. Means have been proposed for fixing the reflector and the metal casing by inserting the claw-shaped bent portion of the casing and then bending the claw-shaped bent portion.

  However, the above-described light reflection plate deformation preventing means has a drawback that the processing cost is high because the light reflection plate and the metal casing are fixed.

  The present invention has been made in view of the above-described circumstances, and can prevent deformation of a light reflecting plate obtained by processing a plate material that reflects light into a three-dimensional shape and reduce processing costs. The purpose is to provide.

  In order to achieve the above-mentioned object, the present invention comprises a plurality of molded pieces made of a plate material that reflects light, and having a bottom portion and inclined portions extending obliquely upward and continuously provided at both widthwise end portions of the bottom portion. Provided is a light reflection plate characterized by being arranged in parallel so that upper end portions of inclined portions of adjacent molding pieces are in contact with each other.

  In the present invention, since the plurality of molded pieces are not continuous and are separate from each other, deformation of the entire light reflecting plate is effectively prevented. Moreover, in this invention, since a light reflection board can be produced only by arrange | positioning several shaping | molding pieces in parallel, processing time can be shortened and processing cost can be made cheap.

  Hereinafter, the present invention will be described in more detail. In the present invention, a molded piece made of a plate material that reflects light is not necessarily limited, but a plastic molded product that reflects light, or a plastic processed product that reflects light, such as a plastic film or sheet that reflects light, and the like. A laminate with a metal plate is preferred. In this case, examples of the plastic that reflects light include polyethylene, polypropylene, polystyrene, polyvinyl chloride, polychlorinated biphenyl, polyethylene terephthalate, polycarbonate, polybutylene terephthalate, polyamide, polyacetal, polyphenylene ether, polysulfone, and polyethersulfone. , Polyarylate, polyamideimide, polyetherimide, polyimide, polyetheretherketone, liquid crystal polymer, fluororesin, cyclic olefin resin, or a copolymer or mixture thereof. Of these, polyesters such as polyethylene terephthalate, polypropylene, and cyclic olefin resins are preferred because of their good heat resistance and impact resistance.

  More specifically, a preferable example of the plastic that reflects light is a thermoplastic resin having fine bubbles or pores having an average bubble diameter of 50 nm or more and 50 μm or less inside. As such a thermoplastic resin, for example, an extruded sheet of polyethylene terephthalate is impregnated with carbon dioxide under high pressure and then heated and foamed, and the light reflection made of foamed plastic with an internal cell diameter of 50 μm or less is used. There are sheets (for example, MCPET (registered trademark) manufactured by Furukawa Electric Co., Ltd.).

  Another preferable example of the plastic that reflects light is a thermoplastic resin containing a filler, in which a large number of voids are formed with the filler as a nucleus. In this case, the thermoplastic resin containing the filler is a porous film in which a number of voids are formed with the filler as a core by forming an unstretched film or sheet containing the filler and stretching the unstretched film or sheet. It is preferably a stretched film or sheet.

  Additives such as antioxidants, ultraviolet inhibitors, lubricants, pigments, reinforcing agents and the like can be appropriately added to the plastic that reflects light. Moreover, you may form the coating layer containing these additives on a plastic.

  In the present invention, the method for producing the molded piece is not particularly limited, but it can be produced using a press working method, a bending working method, or the like. When a plastic sheet is used to produce a molded piece by a bending method, cuts penetrating from one surface of the plastic sheet to the opposite surface are intermittently formed along a straight line, and the plastic sheet is bent along the cuts. Thus, a molded piece with less strain can be produced.

  In the present invention, the peak portions are formed by the pair of inclined portions by bringing the upper ends of the inclined portions of the adjacent molded pieces into contact with each other. In this case, the cross-sectional shape of the mountain portion can be formed in a mountain shape such as a triangle, a semi-polygon, a semi-circle, and a semi-ellipse, but is not limited thereto. It is particularly preferable that the bottom and the inclined part of the molded piece are each rectangular and the cross-sectional shape of the peak is triangular.

  According to the present invention, it is possible to satisfactorily prevent the light reflecting plate from being deformed, to reduce the processing cost, and to reduce the cost.

  Next, although the embodiment of the light reflection board concerning the present invention is shown with reference to drawings, the present invention is not limited to the following example. FIG. 1 is a perspective view showing an example of a molded piece used for manufacturing a light reflecting plate according to the present invention, FIG. 2 is a perspective view of a light reflecting plate manufactured using the molded piece, and FIG. 3 is a side view of the light reflecting plate. FIG.

  The molded piece 10 of this example is made of a plastic sheet that reflects light, and has a rectangular bottom portion 12 and a rectangular inclined portion 14 that extends diagonally upward and is provided continuously at both widthwise ends of the bottom portion 12.

  When a light reflecting plate is produced using the molded piece 10 of this example, as shown in FIGS. 2 and 3, a plurality of molded pieces 10 are arranged so that the upper ends of the inclined portions 14 of adjacent molded pieces 10 are in contact with each other. The light reflectors 20 are arranged in parallel so as to be in contact with each other, thereby forming the light reflecting plate 20 having the crest portions 18 having a triangular section formed by the pair of inclined portions 14. The plurality of molded pieces 10 may be fixed to the arrangement location of the light reflecting plate or the substrate with a double-sided adhesive tape or the like, or may be arranged in the casing, and the fixing means for the plurality of molded pieces 10 is not particularly limited. The light reflection plate 20 of this example is used as a reflection plate for a backlight of a liquid crystal display device, for example. In this case, the light source 22 is disposed between the peaks 18.

  Next, although an example is shown, the present invention is not limited to the following example.

(Example)
As a plastic sheet that reflects light, a polyethylene terephthalate sheet (MCPET manufactured by Furukawa Electric Co., Ltd.) having an internal bubble diameter of 50 μm or less and a thickness of 1 mm was used to produce the molded piece shown in FIG. 1 by bending. Then, the light reflection plate (light reflection plate for backlight of liquid crystal display device) shown in FIGS. 2 and 3 was produced using the molded piece. In this case, the some molded piece was fixed to the arrangement | positioning location of a light reflection board with the double-sided adhesive tape. This light reflecting plate was not deformed.

(Comparative example)
As a plastic sheet for reflecting light, a polyethylene terephthalate sheet (MCPET manufactured by Furukawa Electric Co., Ltd.) having an internal bubble diameter of 50 μm or less and a thickness of 1 mm is used. Cuts penetrating to the surface were intermittently formed along a straight line, and the plastic sheet was bent into a valley along the cuts, thereby obtaining an integrated light reflecting plate having the shape shown in FIGS. Regarding the bending process, the metal mold was not used, and the jig was bent one by one using a jig shaped like the shape of the valley. This light reflecting plate was deformed due to strain during molding and shrinkage after molding.

It is a perspective view which shows an example of the shaping | molding piece used for preparation of the light reflecting plate which concerns on this invention. It is a perspective view of the light reflection board produced using the shaping | molding piece of FIG. It is a side view of the same light reflecting plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Molding piece 12 Bottom part 14 Inclination part 18 Mountain part 20 Light reflecting plate

Claims (3)

  A plurality of molding pieces made of a plate material that reflects light and having a bottom portion and slant portions extending obliquely upward connected to both ends in the width direction of the bottom portion, and upper ends of the sloping portions of adjacent molding pieces A light reflecting plate, wherein the light reflecting plates are arranged in parallel so as to contact each other.   The light reflecting plate according to claim 1, wherein a bottom portion and an inclined portion of the molded piece are each rectangular. The light reflection according to claim 1, wherein the molded piece is a thermoplastic resin molded product or processed product having fine bubbles or pores having an average cell diameter of 50 nm or more and 50 μm or less inside. Board.

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