JP2013197024A - Shelf board and storehouse including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shelf board having a function as a lighting means for reducing glare and shade and utilizing a space efficiently, without disturbing air circulation which is important in a storehouse such as a refrigerator, and provide a storehouse including the shelf board.SOLUTION: A shelf board is formed of a light guide plate formed by dispersing light diffusing particles in a base material made of translucent resin, and two or more of LEDs. The light guide plate has an incident face, an emission face orthogonal to the incident face, an opposite face opposed in parallel with the emission face, and through-holes penetrating the emission face and the opposite face. The LEDs are so arranged so as to make light incident on the incident face without contact with arbitrary imaginary straight lines which are orthogonal to the incident face of the light guide plate and pass through the through-holes.

Description

  The present invention relates to a shelf board. More specifically, the present invention relates to a shelf board that has LEDs and functions as an illuminating unit, and a storage that includes the shelf board, preferably a refrigerator.

  Conventionally, incandescent bulbs have been widely used as lighting fixtures, but from the viewpoint of energy saving, replacement with lighting fixtures with lower power consumption is in progress. Among them, an LED that is easy to realize an emission color close to an incandescent light bulb has been attracting attention.

However, since LEDs have high directivity, the emitted light is dazzling and shadows are easily generated. On the other hand, a surface light emitter is known in which an LED is disposed on a side surface of a light guide plate, and a main surface positioned perpendicular to the side surface is an emission surface (see Patent Document 1). In such a surface light emitter, since the emitted light is uniformly diffused over the entire emission surface, reduction of glare can be expected. However, illumination using such a surface light emitter is not only in the way, but it may hinder air circulation, particularly in a storage such as a refrigerator.

International Publication No. 2010/113422 Pamphlet

  The present invention has been made in view of such circumstances, and illumination means that can reduce the occurrence of dazzling and shadows, can use space without waste, and does not hinder the circulation of air that is important in a storage such as a refrigerator. It aims at providing the shelf board which has a function as. Moreover, it is another object to provide a storage provided with such a shelf board.

In order to solve the above problems, the present invention provides:
[1] A shelf plate composed of a light guide plate in which light diffusing particles are dispersed inside a base material made of a translucent resin, and two or more LEDs,
The light guide plate has an entrance surface, an exit surface perpendicular to the entrance surface, an opposite surface facing the exit surface in parallel, and a through-hole penetrating the exit surface and the opposite surface;
A shelf board in which the LED is arranged so as to make light incident on the incident surface without being in contact with any imaginary straight line perpendicular to the incident surface of the light guide plate and passing through a through hole;
[2] The shelf board of the above [1], comprising two LEDs closest to and equidistant from the through hole;
[3] The shelf plate according to the above [1] or [2], wherein the through hole has a slit shape parallel to a perpendicular to the incident surface;
[4] The shelf board according to any one of the above [1] to [3], which is for storage use;
[5] The shelf board of [4], wherein the storage is a refrigerator;
[6] A storage provided with the shelf of [4] above; and [7] The storage of [6] above which is a refrigerator.

  The shelf board of this invention is useful as an illuminating device using LED as a light source, and can suppress the occurrence of glare and shadow. In addition, it will not get in the way by replacing existing shelf boards. Furthermore, since the light guide plate included in the shelf board of the present invention has a through hole, the circulation of air important in the storage of the present invention including the shelf board, in particular, the refrigerator is not hindered.

1 is a perspective view showing a first embodiment of the present invention. It is a top view which shows the 1st Embodiment of this invention. It is a top view which shows the modification of 1st Embodiment of this invention. It is a top view which shows another modification of 1st Embodiment of this invention. It is a top view which shows another modification of 1st Embodiment of this invention. It is a top view which shows the 2nd Embodiment of this invention. It is a top view which shows the 3rd Embodiment of this invention. It is a top view which shows the comparative example of this invention.

(Light guide plate)
Although there is no restriction | limiting in particular in the shape of the light-guide plate with which the shelf board of this invention is equipped, Usually, it is a plate shape which makes the surface opposite to an output surface the largest surface (main surface), and rectangular shape is preferable as an outer edge shape of a main surface. . The light guide plate has a side surface that connects the outer edge of the exit surface and the opposite surface, and at least one of the side surfaces is an entrance surface. The entrance surface is perpendicular to the exit surface and the opposite surface. When the outer edge shape of the main surface is rectangular, the side surfaces are four, and the incident surface may be one surface or two surfaces facing each other.

  The opposite surface of the light guide plate may emit light in the same manner as the emission surface, or may be a surface that reflects light. If the opposite surface has the same configuration (material, shape, etc.) as the exit surface, it functions in the same manner as the exit surface. Further, the opposite surface may have an uneven structure, and a reflective layer made of metal or the like may be further provided on the opposite surface. The amount of light emitted from the opposite surface can be adjusted by the shape of the concavo-convex structure or the coverage of the reflective layer.

  The light guide plate is formed by dispersing light diffusing particles inside a base material made of a translucent resin. Examples of the light-transmitting resin include acrylic resins, styrene resins, and polycarbonate resins. From the viewpoints of transparency and impact resistance, acrylic resins and polycarbonate resins are preferred. A plurality of translucent resins may be mixed and used, or a multi-layer configuration in which a plurality of layers having different types and compositions of translucent resins are provided.

  Examples of the light diffusing particles used in the present invention include titanium oxide, zinc oxide, and barium sulfate.

  Preferably, the absolute value (hereinafter referred to as “Δn”) of the difference between the refractive index of the translucent resin that is the base material of the light guide plate and the refractive index of the light diffusing particles is from 0.3 to 3.0, 0.4 or more and 1.5 or less are more preferable. When Δn is smaller than 0.3 or larger than 3.0, the ratio of the outgoing light from the outgoing surface may decrease and the brightness of the shelf board may be inferior.

  Further, the product of Δn and the weight average diameter d (mm) of the light diffusing particles is preferably in the range of 0.0001 to 0.1, more preferably in the range of 0.0002 to 0.05, More preferably, it is in the range of 0.0005 to 0.01. When this product is less than 0.0001, the hue of the emitted light is different within the emission surface, and the scattered light may be bluish near the light source, and may be yellowish at a position away from the light source. When this product exceeds 0.1, the light scattered by the light diffusing particles is visually recognized as a bright spot, and the appearance quality may be impaired.

  The content of the light diffusing particles is preferably in the range of 0.00001 to 0.1% by mass with respect to the light guide plate from the viewpoint of light utilization efficiency and in-plane luminance uniformity, and 0.00002 to The range of 0.05% by mass is more preferable, the range of 0.00005 to 0.01% by mass is more preferable, and the range of 0.0001 to 0.005% by mass is particularly preferable.

  The haze value measured in the direction from the exit surface to the opposite surface of the light guide plate (hereinafter referred to as “thickness direction”) is preferably 30% or less, more preferably 20% or less, and even more preferably 10% or less.

  The light emitted from the LED travels inside the light guide plate while repeating total reflection. The thickness of the light guide plate is preferably in the range of 1 to 15 mm, more preferably in the range of 2 to 10 mm. The transparency of the light guide plate is increased when the thickness of the light guide plate is 15 mm or less, and the strength of the shelf plate is increased when the thickness is 1 mm or more.

  The through-hole penetrating from the exit surface of the light guide plate to the opposite surface preferably penetrates with a uniform cross-sectional area perpendicular to the exit surface and the opposite surface. A plurality of through holes may be provided, and the shape and size of each through hole may be different.

  The inner surface of the through hole provided in the light guide plate preferably has a surface roughness (Ra) of 1 μm or less, more preferably 0.5 μm or less. When the surface roughness (Ra) of the inner surface of the through hole is 1 μm or less, light from the incident surface is likely to be totally reflected when it hits the through hole. Uniform brightness can be achieved. Here, Ra is defined in JIS B0601-2001.

  Although there is no particular limitation on the cross-sectional shape of the through-hole as viewed from the exit surface side, a shape that is axisymmetric with respect to a predetermined perpendicular to the entrance surface is preferable from the viewpoint of uniformly emitting light. For example, a circular shape, an elliptical shape, a rectangular shape, etc. can be mentioned, and the shape of the object to be placed on the shelf plate can be selected, but from the viewpoint of uniformity of the luminance in the exit surface, a slit shape parallel to the perpendicular of the entrance surface Is preferred. Here, the slit shape parallel to the normal of the incident surface is a shape in which the cross-sectional shape of the through-hole has two straight lines parallel to the normal and the dimension in the normal direction is the maximum dimension in the cross-section. Specific examples of the cross-sectional shape include a rectangular shape having a side parallel to the perpendicular as a long side, and a short side of the rectangle replaced with a curve.

Although there is no restriction | limiting in particular in the dimension per through-hole, Considering the retainability as a shelf board, the cross-sectional area parallel to the main surface of one through-hole is 0.01-10 area% of a main surface. Is preferable, the range of 0.05 to 5 area% is more preferable, and the range of 0.1 to 2 area% is more preferable.
In consideration of the strength as a shelf board, the sum of the cross-sectional areas parallel to the main surfaces of all the through holes is preferably in the range of 0.1 to 30 area% of the main surface, and 0.5 to 20 area%. Is more preferable, and a range of 1 to 15% by area is more preferable.

  The shelf board of this invention has at least 2 or more LED arrange | positioned so that light may enter into an entrance plane, and it is preferable to have 2 or more LED per entrance plane. In order to arrange the LED so that the light is incident on the incident surface, it is only necessary that the light emitting part of the LED is disposed so as to face the incident surface, whereby the main light emitting direction of the LED and the incident surface are perpendicular to each other. Become.

  As a manufacturing method of a light-guide plate, the method of shape | molding after mixing translucent resin used as a base material and light-diffusion particle | grains is mentioned. Examples of the molding method include cast molding, extrusion molding, and injection molding.

  The through hole of the light guide plate may be formed by a drill or a router grinder after the plate member is formed by the above forming method. Moreover, you may form a through-hole simultaneously with shaping | molding by injection molding.

(LED)
Although there is no limitation in particular in the light emission color of LED with which the shelf board of this invention is equipped, the so-called light bulb color whose color temperature is 2700K-3000K which does not feel uncomfortable compared with the conventional illuminating device is preferable. The dimension of the light emitting portion of the LED is preferably shorter than the distance between the light emitting surface and the opposite surface.

(Position relationship between through hole and LED)
In the shelf plate of the present invention, the light supplied from the LED to the incident surface scatters the light in the light guide plate, and a part of the light exits from the output surface while being perpendicular to the incident surface (hereinafter referred to as the light guide direction). Proceed toward. The LED is arranged so that light is incident on the incident surface without being in contact with an arbitrary imaginary straight line that is perpendicular to the incident surface and passes through the through hole. Can be suppressed.
This will be described using a first example regarding the positional relationship between the through hole and the LED shown in FIGS. In the following description, the direction perpendicular to the light guide direction connecting the two main surfaces (the surface opposite to the exit surface) of the light guide plate is referred to as the thickness direction. A direction perpendicular to both the light guide direction and the thickness direction of the light guide plate is referred to as the width direction of the light guide plate. In FIG. 1, the direction of arrow A is the thickness direction, the direction of arrow B is the width direction, and the direction of arrow C is the light guide direction. In this example, the shelf plate 1 includes a light guide plate 11 and two LEDs 12 that are opposed to the incident surface and are spaced apart in the width direction.
The through hole 13 of the light guide plate 11 has a slit shape parallel to the light guide direction.
FIG. 2 shows an imaginary straight line 14 passing through the through hole 13 perpendicular to the incident surface (that is, parallel to the light guide direction). The LEDs 12 are respectively arranged at positions that are perpendicular to the incident surface and do not contact any imaginary straight line 14 that passes through the through hole 13.
Since the light guide plate 11 is provided with slit-like through holes 13 as shown in FIG. 2, the light entering from the LED is not prevented from proceeding in the light guide direction, and the intensity of the emitted light is uniform. , Can reduce glare.

  The shelf board of the present invention preferably includes two LEDs that are closest to and equidistant from the through hole from the viewpoint of emitting light of uniform intensity.

  Hereinafter, the second to sixth examples will be described as modified examples of the positional relationship between the through holes and the LEDs in the shelf board of the present invention with reference to the drawings.

FIG. 3 is a second example regarding the positional relationship between the through hole and the LED.
In this example, the shelf plate 1 includes a light guide plate 11 and two LEDs 12 that are opposed to the incident surface and are spaced apart in the width direction. The light guide plate 11 is provided with two slit-like through holes 13 that penetrate in the thickness direction and are parallel to the perpendicular of the incident surface.
A virtual straight line 14 that passes through the through-hole 13 and is parallel to the perpendicular of the incident surface is shown in the figure. The two LEDs 12 are respectively provided at positions that do not contact the virtual straight line 14.

FIG. 4 is a third example regarding the positional relationship between the through hole and the LED.
In this example, the shelf plate 1 includes a light guide plate 11 and two LEDs 12 that are opposed to the incident surface and are spaced apart in the width direction. The light guide plate 11 is provided with slit-like through-holes 13 parallel to the three light guide directions in the light guide direction. The slit-like through-hole 13 can be considered as the slit-like through-hole 13 in the first example divided into three in the light guide direction.

FIG. 5 is a fourth example regarding the positional relationship between the through hole and the LED.
In this example, the shelf plate 1 includes a light guide plate 11 and two LEDs 12 that are opposed to the incident surface and are spaced apart in the width direction. The light guide plate 11 is provided with five circular through holes 13 arranged in the light guide direction.
A virtual straight line 14 that passes through the through-hole 13 and is parallel to the perpendicular of the incident surface is shown in the figure. The two LEDs 12 are respectively provided at positions that do not contact the virtual straight line 14.

FIG. 6 is a fifth example regarding the positional relationship between the through hole and the LED.
In this example, the shelf plate 1 includes a light guide plate 11 and three LEDs 12 that are opposed to the incident surface and are spaced apart from each other in the width direction. The light guide plate 11 is provided with two slit-like through-holes 13 that penetrate in the thickness direction and are parallel to the perpendicular of the incident surface, separated in the width direction.
A virtual straight line 14 passing through the through-hole 13 and parallel to the perpendicular of the incident surface is indicated by a one-dot chain line in the figure. Each of the three LEDs 12 is provided at a position not in contact with the alternate long and short dash line.

FIG. 7 is a sixth example regarding the positional relationship between the through hole and the LED.
In this example, the shelf plate 1 includes a light guide plate 11 and three LEDs 12 that are opposed to the incident surface and are spaced apart in the width direction. The light guide plate 11 is provided with four slit-like through-holes 13 that penetrate in the thickness direction and are parallel to the perpendicular of the incident surface.
A virtual straight line 14 that passes through the through-hole 13 and is parallel to the perpendicular of the incident surface is shown in the figure. The three LEDs 12 are respectively provided at positions not in contact with the virtual straight line 14.

  The method for fixing the LED and the light guide plate is not particularly limited, and examples thereof include a method in which the light emitting portion of the LED is opposed to the side surface of the light guide plate and fixed with a transparent adhesive.

  Although there is no restriction | limiting in particular about the method of installing a shelf board, It is desirable to fix a part of outer edge of a light-guide plate from a viewpoint which does not prevent light emission. For example, when used as a shelf plate installed inside a box such as a refrigerator, the outer edge of the light guide plate may be bonded to the inner wall of the box, or the light guide plate may be fitted into the unevenness provided on the inner wall of the box. The storage of the present invention may be provided with at least one shelf according to the present invention, and may be provided with a plurality of shelf boards according to the present invention as necessary. By using the shelf board of the present invention in the storage of the present invention, preferably a refrigerator, the circulation of the air in the warehouse can be illuminated, the interior can be illuminated, and the power consumption is low and there is no glare.

  Hereinafter, the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[Example 1]
Titanium oxide particles (weight average particle diameter) as light diffusing particles in a methacrylic resin ("Parapet" manufactured by Kuraray Co., Ltd., refractive index = 1.494), which is a translucent resin, so that the content is 0.00075% by mass. = 1 μm, refractive index = 2.72), and after mixing, extrusion is performed by an extruder to obtain a resin plate in which light diffusion particles are dispersed in a methacrylic resin having a thickness of 5 mm. Cut in parallel, a rectangular parallelepiped having a major surface dimension of 200 mm short side, 240 mm long side, and 5 mm thickness was obtained. When the haze value of the resin plate was measured by “Haze Meter HZ-1” manufactured by Suga Test Instruments Co., Ltd., it was 5.0% and the transparency was high.

  Next, a slit-shaped through-hole having a width of 5 mm and a length of 110 mm, which was perpendicular to the resin plate main surface and parallel to the short side of the main surface, was opened at the center of the main surface of the obtained resin plate. In addition, the both ends of the longitudinal direction of a slit-shaped through-hole are semicircular. Next, the inner surface of the through hole and the side surface of the resin plate were polished by buffing to give a mirror finish (Ra = 0.2 μm or less) to obtain a light guide plate.

  Next, using the side surface including one long side of the obtained light guide plate as an incident surface, the light emitting part of two LEDs (“NIFA Chemical Co., Ltd.“ LED NFSW036BT ”) is used so that light is incident on the incident surface. Glued with a transparent adhesive. The bonded positions are 60 mm from both ends in the width direction of the incident surface of the light guide plate, and are two points that are the centers in the thickness direction. Thus, the shelf board of the present invention was obtained.

[Comparative Example 1]
Except that the number of slit-shaped through-holes is two and the width direction is changed to 1/4 and 3/4 positions as shown in FIG. 8, in other words, from the left and right ends in the width direction to positions 60 mm respectively. A light guide plate was produced in the same manner as in Example 1.

Next, using the side surface including one long side of the obtained light guide plate as an incident surface, the light emitting part of two LEDs (“NIFA Chemical Co., Ltd.“ LED NFSW036BT ”) is used so that light is incident on the incident surface. Glued with a transparent adhesive. The bonded positions are 60 mm from both ends in the width direction of the incident surface of the light guide plate, and are two points that are the centers in the thickness direction.
In the shelf plate thus manufactured, the LED is in contact with the virtual straight line 14 that is perpendicular to the incident surface of the light guide plate and passes through the through hole.

[Evaluation]
With respect to the shelf boards of Example 1 and Comparative Example 1, 2.8 V was applied to each LED, and the dazzling and in-plane brightness uniformity were visually evaluated. As a result, the shelf board of the example was bright and uniform in brightness, and no shadow was observed. On the other hand, the shelf of the comparative example was uneven in intensity of the emitted light, and a shadow was observed. Furthermore, the space between the LED and the through hole was particularly bright and felt dazzling.

  As described above, the shelf board of the present invention can suppress the occurrence of glare and shadows.

1 Shelf plate 11 Light guide plate 12 LED
13 Through hole 14 Virtual straight line

Claims (7)

A light guide plate in which light diffusion particles are dispersed inside a base material made of a light-transmitting resin, and a shelf plate made of two or more LEDs,
The light guide plate has an entrance surface, an exit surface perpendicular to the entrance surface, an opposite surface facing the exit surface in parallel, and a through-hole penetrating the exit surface and the opposite surface;
The shelf board, wherein the LEDs are arranged so that light is incident on the incident surface without contacting any virtual straight line that is perpendicular to the incident surface of the light guide plate and passes through a through hole.   The shelf board of Claim 1 provided with two LED which is the nearest and equidistant with the said through-hole.   The shelf plate according to claim 1 or 2, wherein the through hole has a slit shape parallel to a perpendicular line of the incident surface.   The shelf board according to any one of claims 1 to 3, wherein the shelf board is used for storage.   The shelf board according to claim 4, wherein the storage is a refrigerator.   A store | warehouse | chamber provided with the shelf board of Claim 4.   The storehouse according to claim 6 which is a refrigerator.

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