Refrigerator

Abstract

The invention provides a refrigerator which is provided with a shelf that can illuminate from a surface portion and is not easily visually recognized even if a fingerprint is attached to the surface portion. A refrigerator (2) is provided with: a shelf (10) having light transmission; a light source (20) that irradiates light to the front side from the rear side surface of the shelf (10); and a plurality of light diffusion dots (18) formed on at least one of the upper surface (10A) and the lower surface (10B) of the shelf (10), the size (S) of the gap between adjacent light diffusion dots (18) being equal to or less than the interval of the ridge lines of the human finger.

Description

Technical Field

[0001] The present invention relates to a refrigerator having a shelf that functions as a light guide plate. Background Art

[0002] In a refrigerator, it is known that a light source is installed on a shelf having translucency, and light is emitted from the surface portion of the shelf to function as interior lighting of the refrigerator. However, if fingerprints adhere to the surface portion of the shelf, it not only affects the lighting but also the fingerprints are easily visually recognized. To address this situation, a refrigerator having a printed layer with a hydrophobic group bound to inorganic particles on the surface of the shelf has been proposed (for example, refer to Patent Document 1).

[0003] Patent Document 1: Japanese Patent No. 6818285.

[0004] In the refrigerator described in Cited Document 1, fingerprints are less likely to adhere to the surface of the shelf due to the hydrophobic group, but attachment cannot be completely prevented. As a result, fingerprints adhere to the surface of the shelf with use, and there is a problem that the fingerprints are easily visually recognized. Summary of the Invention

[0005] Accordingly, an object of the present invention is to solve the above problems and provide a refrigerator having a shelf that can illuminate from the surface portion and is not easily visually recognized even when fingerprints adhere to the surface portion.

[0006] To achieve the above object, a first aspect of the present invention relates to a refrigerator including:

[0007] a shelf having translucency;

[0008] a light source that irradiates light forward from a side surface on the rear side of the shelf; and

[0009] a plurality of light diffusion points formed on at least one of the upper surface and the lower surface of the shelf,

[0010] wherein a size of a gap between adjacent light diffusion points is equal to or less than an interval of ridge lines of a human finger.

[0011] Light emitted from the light source travels forward while being totally reflected by the upper and lower surfaces of the translucent shelf. At this time, if a plurality of light diffusion points are formed on the upper surface or the lower surface of the shelf, the light is reflected by the light diffusion points and emitted to the outside from the surface opposite to the surface on which the light diffusion points are provided. Thereby, the shelf can be used as interior lighting of the refrigerator, and an interior with excellent appearance can be achieved.

[0012] However, when the user's finger touches the surface of the shelf, fingerprints are attached to the surface due to sebum, oil on the finger, etc., and there is a concern that the attached fingerprints may be visually recognized. In particular, when light is directed to the shelf, the fingerprints become more noticeable due to the shadow difference.

[0013] In this method, the size of the gap between adjacent light diffusion points is configured to be less than the spacing of the ridges of fingers. As a result, there must be light reflected from the light diffusion points in the space between the ridges and the ridges, and it enters the eyes of the visual recognizer. The shape of the ridge becomes difficult to recognize through the light between the ridges and the ridges. Therefore, in this method, it is possible to provide a refrigerator with a shelf that can be illuminated from the surface portion and is not easily visually recognized even if fingerprints are attached to the surface portion.

[0014] In addition to the first aspect, a second aspect of the present invention relates to a refrigerator, wherein:

[0015] The light diffusion point is roughly circular.

[0016] If the diameter of the light diffusion point is set to D,

[0017] The distance between the centers of the adjacent light diffusion points is L.

[0018] Let the size of the above gap be S,

[0019] Then the relationship S=L-D exists.

[0020] By using substantially circular light diffusion dots, a plurality of light diffusion dots can be easily and efficiently provided on the shelf by printing, etc. The size of the gap between adjacent light diffusion dots can be reliably set by the equation S=L-D.

[0021] In addition to the second aspect, a third aspect of the present invention relates to a refrigerator having a relationship of S≤0.5 mm.

[0022] The spacing between the ridges of human fingers is considered to be 0.4 to 0.5 mm. By setting S ≤ 0.5 mm, the size S of the gap between the light diffusion points can be reliably set to be less than the spacing between the ridges of human fingers, and a shelf that is not easily visually identified even if fingerprints are attached to the surface can be realized.

[0023] A fourth aspect of the present invention, in addition to any one of the first to third aspects, is a refrigerator in which the arrangement density of the light diffusion points is 0.39 or more.

[0024] In this aspect, by setting the arrangement density of the light diffusion points to 0.39 or more, it is possible to realize a shelf that is reliably difficult to be visually recognized even if fingerprints are attached to the surface portion.

[0025] The fifth aspect of the present invention relates to a refrigerator, which includes:

[0026] A shelf having translucency;

[0027] A light source that irradiates light from the side surface at the rear of the shelf toward the front side; and

[0028] A plurality of light diffusion points formed on at least one of the upper surface and the lower surface of the shelf,

[0029] The arrangement density of the light diffusion points is 0.39 or more.

[0030] In this aspect, by setting the arrangement density of the light diffusion points to 0.39 or more, it is possible to realize a shelf that can illuminate the surface portion of the shelf and is reliably less likely to be visually recognized even when fingerprints are attached to the surface portion.

[0031] The sixth aspect of the present invention relates to a refrigerator, which includes:

[0032] A shelf having translucency;

[0033] A light source that irradiates light from the side surface at the rear of the shelf toward the front side; and

[0034] A plurality of light diffusion points formed on at least one of the upper surface and the lower surface of the shelf,

[0035] The illuminance of the surface of the shelf on the side opposite to the surface on which the light diffusion points are arranged based on the light source is 220 Lx or less, and the arrangement density of the light diffusion points is 0.15 or more.

[0036] When the illuminance is 220 Lx or less, it has sufficient brightness to function as the illumination inside the box. According to this aspect, it is possible to illuminate from the surface portion, and by limiting the illuminance of the light emitted from the surface portion, even with a smaller arrangement density of the light diffusion points, it is possible to make it less likely to visually recognize fingerprints attached to the surface portion.

[0037] As described above, in the present invention, it is possible to provide a refrigerator having a shelf that can illuminate from the surface portion and is less likely to be visually recognized even when fingerprints are attached to the surface portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a perspective view schematically showing a refrigerator according to an embodiment of the present invention.

[0039] Figure 2 It shows Figure 1 A perspective view showing an outline of a shelf of the refrigerator shown.

[0040] Figure 3 is a side cross-sectional view schematically showing the way light travels in the shelf shown below. Figure 2

[0041] Figure 4 are pictures showing the surface portions of Samples 1 to 4 of the shelf used in the experiment.

[0042] Figure 5A is a diagram showing the dot patterns of the light diffusion points of Samples 1 to 4.

[0043] Figure 5B is a table showing the light diffusion point diameters of the respective regions of Samples 1 to 4.

[0044] Figure 6A is an explanatory diagram of an equation for calculating the size S of the gap between adjacent light diffusion points.

[0045] Figure 6B is a table showing the relationship between the gap between light diffusion points and the visibility of fingerprints.

[0046] Figure 7 is a table showing the relationship between the illuminance of the surface portion and the visibility of fingerprints.

[0047] Figure 8A is a side cross-sectional view for explaining the case where fingerprints attached to the surface portion are not easily visually recognized on a shelf without light diffusion points.

[0048] Figure 8B is a side cross-sectional view for explaining the case where fingerprints attached to the surface portion are not easily visually recognized on a shelf in which a plurality of light diffusion points are arranged at a prescribed gap interval.

[0049] Figure 9A is a side cross-sectional view schematically showing the way light travels when the size of the gap between adjacent light diffusion points is greater than the interval between the ridges of a human finger.

[0050] Figure 9B is a side cross-sectional view schematically showing the way light travels when the size of the gap between adjacent light diffusion points is less than or equal to the interval between the ridges of a human finger.

[0051] Figure 10 is a table showing the relationship between the arrangement density of light diffusion points and the visibility of fingerprints.

[0052] Figure 11 is a graph showing the relationship between the illuminance of the surface portion of the shelf and the arrangement density of light diffusion points.

[0053] Explanation of Reference Numerals

[0054] ​2…Refrigerator; 4…Door; 6…Refrigerating compartment; 10…Shelf; 10A…Upper surface; 10B…Lower surface; 12…Rear side surface; 14…Front side surface; 16…Side surfaces on both sides; 18…Light diffusion point; 20…Light source; 22…Light source main body part. Detailed implementation mode

[0055] Hereinafter, an implementation mode for implementing the present invention will be described with reference to the drawings. The implementation mode described below is to embody the technical idea of the present invention. Unless otherwise specified, the present invention is not limited to the following implementation mode.

[0056] Sometimes multiple embodiments are shown separately, but the structures shown in different embodiments can be combined, or structural parts can be replaced. In the following embodiments, descriptions of matters common to the above embodiments are omitted, and only differences are described. In particular, the same functions and effects based on the same structure are not mentioned successively in each embodiment.

[0057] For the sake of clarity in the description, sometimes the sizes, positional relationships, etc. of the components shown in the drawings are exaggerated for illustration. In the following description and drawings, the refrigerator is placed on a horizontal plane, the side with the door is taken as the front side, the opposite side is taken as the rear side, and the left and right directions when viewed from the front side are referred to as left and right for description. In the drawings, the progress of light in the shelf is schematically indicated by solid lines, dashed lines or dotted line arrows.

[0058] (Refrigerator and shelf according to the first embodiment of the present invention)

[0059] First, refer to Figure 1 and Figure 2 , and a refrigerator and a shelf according to an embodiment of the present invention will be described. Figure 1 is a perspective view schematically showing a refrigerator according to an embodiment of the present invention. Figure 2 is a perspective view showing the outline of the shelf of the refrigerator shown in Figure 1 .

[0060] In the refrigerator 2 according to the present embodiment, a refrigerating compartment 6 is arranged on the upper side, and a freezing compartment is arranged on the lower side. In Figure 1 , a state in which the door 4 for opening and closing the front opening of the refrigerating compartment 6 is open is shown. The shelf 10 is a partition that divides the refrigerating compartment 6, which is a storage area of the refrigerator 2, into upper and lower parts. For example, the shelf 10 can be placed on a support portion formed to protrude inward from the left and right inner surfaces of the refrigerating compartment 6, and the shelf 10 can be arranged in the refrigerating compartment 6. At this time, the side surfaces 16 on both sides of the shelf 10 are arranged to face the left and right inner surfaces of the refrigerating compartment 6. In addition, the storage area where the shelf 10 is arranged is not limited to the refrigerating compartment 6, and the shelf 10 can also be arranged in any other storage area such as the freezing compartment.

[0061] The shelf 10 is formed of a light-transmissive member and functions as a light guide plate. The shelf 10 can be formed of a light-transmissive resin material such as acrylic, or can also be formed of a light-transmissive glass material. In addition, the inside of the shelf 10 does not contain light-diffusing particles. The light-transmissive shelf 10 can be transparent or colored.

[0062] A light source main body portion 22 having a plurality of light sources 20 is installed on the rear side of the shelf 10. The light source main body portion 22 has a U-shaped or C-shaped side surface shape, and the rear end portion of the shelf 10 is inserted into the opening of the U-shaped (C-shaped) light source main body portion 22, and the two are fitted together.

[0063] The light source main body portion 22 is preferably formed of an elastic material such as resin. The opening size of the U-shaped (C-shaped) of the light source main body portion 22 is formed to be slightly smaller than the outer shape of the shelf 10. When the shelf 10 is inserted into the opening of the U-shaped (C-shaped) light source main body portion 22, the light source main body portion 22 is elastically deformed slightly outward. Thereby, the light source main body portion 22 is closely attached to the shelf 10, and the light source main body portion 22 can be reliably installed on the shelf 10.

[0064] However, the shape of the light source main body portion 22 is not limited to this. The light source main body portion 22 can also be in the shape of a flat plate. In this case, the light source main body portion 22 can be installed on the shelf 10 using adhesives or other fastening members. Furthermore, it can also be the case where each light source 20 is directly installed on the shelf 10.

[0065] Six light sources 20 are installed on the surface of the light source main body portion 22 that faces the side surface 12 on the rear side of the shelf 10. The six light sources 20 are arranged side by side in the width direction of the shelf, and irradiate light from the side surface 12 on the rear side of the shelf 10 to the front side. As the light source 20, an LED that emits white light is adopted. The light source 20 is controlled, for example, to light up when the door on the front side of the storage area where the shelf 10 is arranged is opened.

[0066] In addition, the light emitted by the LED is not limited to white light, and an LED that emits any other color of light can also be adopted according to the use. The number of the light sources 20 is not limited to this, and any number of light sources 20 of 2 or more can be arranged.

[0067] (The way light travels in the shelf)

[0068] Next, with reference to Figure 3 , the way light travels in the shelf will be described. Figure 3 is a side cross-sectional view schematically showing the way light travels in the shelf shown in Figure 2 . As shown in Figure 3As shown by the arrows of the dashed lines, the light emitted from the light source 20 advances forward while being totally reflected by the upper surface 10A and the lower surface 10B of the shelf 10, and a part of the light is emitted from the front side surface 14.

[0069] In the present embodiment, a plurality of light diffusion points 18 are formed on the lower surface 10B of the shelf 10. A part of the light emitted from the light source 20 is reflected upward by the light diffusion points 18 and is emitted outward from the upper surface 10A of the shelf 10. Thereby, it functions as illumination for irradiating the storage items placed on the shelf 10 from below.

[0070] In addition, it may be the case where the light diffusion points 18 are provided on the upper surface 10A of the shelf 10. In this case, a part of the light emitted from the light source 20 is reflected downward by the light diffusion points 18 and is emitted outward from the lower surface 10B of the shelf 10. Thereby, it functions as illumination for irradiating the storage items placed on the lower side of the shelf 10. Further, it may be the case where the light diffusion points 18 are provided on both the upper surface 10A and the lower surface 10B of the shelf 10. In this case, it functions as double-sided illumination that emits light from both the upper surface 10A and the lower surface 10B of the shelf 10. The light diffusion points 18 can be formed on the upper surface 10A and the lower surface 10B of the shelf 10 by printing, for example.

[0071] As described above, the shelf 10 is formed of a light-transmissive acrylic or glass material, but when the user's finger touches it, sebum, oil attached to the finger, etc. adhere to the surface of the shelf 10. In particular, fingerprints attached to the upper surface 10A or the lower surface 10B of the shelf 10 are easily visually recognized. When the light source 20 is turned on and the surface portions 10A and 10B are used for illumination, the fingerprints are more easily visually recognized.

[0072] In order to address this situation, the inventor focused on the light diffusion points and conducted research on a shelf on which fingerprints are not easily visually recognized. Specifically, samples of shelves with light diffusion points having various dot patterns were trial-produced, fingerprints were attached to the surface portion, a test was conducted on whether the fingerprints were visually recognized, and research was conducted on dot patterns in which fingerprints are not easily visually recognized.

[0073] (Samples of the shelf)

[0074] Refer to Figure 4 、 Figure 5A and Figure 5B for an explanation of the samples of the shelf used in the test. Figure 4 are photos showing the surface portions of samples 1 to 4 of the shelf used in the test. Figure 5A is a diagram showing the dot patterns of the light diffusion points of samples 1 to 4. Figure 5B is a table showing the light diffusion point diameters of each region of samples 1 to 4.

[0075] As Figure 3 shown, in the four samples 1 to 4, light diffusion points are formed on the lower surface of the shelf. The dot patterns of the light diffusion points formed in the samples 1 to 4 are as described below.

[0076] In sample 1, in all regions, substantially circular light diffusion points are formed at the vertices of an equilateral triangle with a side length of 1.7 mm, centered at the position of the vertices. In sample 2, in all regions, substantially circular light diffusion points are formed at the vertices and the center of a square with a side length of 1 mm, centered at the positions of the vertices and the center. In sample 3, in all regions, substantially circular light diffusion points are formed at the vertices of an equilateral triangle with a side length of 2.3 mm, centered at the position of the vertices. In sample 4, in all regions, substantially circular light diffusion points are formed at the vertices of an equilateral triangle with a side length of 1.2 mm, centered at the position of the vertices.

[0077] In samples 1 to 4, the area is divided into six regions A to F from the rear side to the front side. In samples 1, 3, and 4, as moving from region A to region F (from the rear side to the front side), the dot diameter of the light diffusion points becomes larger to 0.5 mm, 0.55 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm. On the other hand, in sample 2, in all regions, the dot diameter of the light diffusion points is 0.5 mm.

[0078] By installing a light source on the side surface at the rear of the samples 1 to 4 of such a shelf and irradiating, light is emitted from the upper surface of the samples 1 to 4 of the shelf. In addition, in the following fingerprint visual recognition test, 10 inspectors performed visual recognition from the upper surface side of the samples 1 to 4 of the shelf. When no one could visually recognize the fingerprint, it was determined as "unable to visually recognize", and when at least some inspectors could visually recognize the fingerprint, it was determined as "able to visually recognize".

[0079] As a preliminary test, examples were formed in which a finger with salad oil attached was brought into contact with the upper surface of samples 1 to 4 and fingerprints were left, and examples in which salad oil was evenly coated on the upper surface of samples 1 to 4 with paper. Then, as described above, the light source was turned on to confirm whether it was possible to visually recognize. As a result, although it was determined that the fingerprint could be visually recognized, the oil-coated part could not be clearly visually recognized. It was clarified that there is also a tendency to be easily able to visually recognize fingerprints in the future.

[0080] (Example 1)

[0081] Next, fingerprints were attached to all regions A to F of Samples 1 to 4, the light source was turned on, and a fingerprint visual recognition test was conducted to see if the fingerprints could be visually recognized. As Example 1, regarding the size S of the gap between adjacent light diffusion points, a confirmation was made as to whether the fingerprints could be visually recognized. Refer to Figure 6A , Figure 6B and Figure 7 for an explanation thereof. Figure 6A is an explanatory diagram of the formula for calculating the size S of the gap between adjacent light diffusion points. Figure 6B is a table showing the relationship between the gap between light diffusion points and the visibility of fingerprints. Figure 7 is a table showing the relationship between the illuminance of the surface part and the visibility of fingerprints.

[0082] As Figure 6A shown, in Samples 1, 3, and 4, light diffusion points with a point diameter D centered at the position C of each vertex of the equilateral triangle dot pattern were formed at the vertices. The center-to-center distance L between adjacent light diffusion points is the same as the length of one side of the equilateral triangle. In Sample 2, light diffusion points with a point diameter D centered at the positions of the vertices and the center of the square dot pattern were formed at the vertices and the center of the square. The center-to-center distance L between adjacent light diffusion points is the same as the length of one side of the square and the distance between the vertex and the center. If the length of one side of the square is set as N, the distance between the vertex and the center becomes N×SQR(2) / 2, which is approximately 70% of the length of one side of the square.

[0083] If the length of one side of the equilateral triangle, the length of one side of the square, and the distance between the vertex and the center of the square are set as the center-to-center distance L, the point diameter is set as D, and the size of the gap between adjacent light diffusion points is set as S, then the size S of the gap can be calculated by S = L - D. The size S of the gap in each region A to F of each of Samples 1 to 4 is as shown in the table of Figure 6B .

[0084] In the Figure 6B table, the samples and regions where 10 testers determined that the fingerprints could not be visually recognized are shown in color (blackened). In Sample 2, in all regions A to F, it was determined that the fingerprints could not be visually recognized.

[0085] The illuminance of the light emitted from the upper surface of Samples 1 to 4 on the shelf varies depending on the distance from the light source and the proportion of the formed light diffusion points. The measurement results of the illuminance of the light on the upper surface in each region A to F of each of Samples 1 to 4 are shown in Figure 7 . Generally, it shows a tendency that the illuminance decreases from the rear side closer to the light source to the front side (the side of A to F). Furthermore, in Samples 1, 3, and 4, the point diameter increases from the rear side to the front side (the side of A to F), so this tendency becomes more significant.

[0086] It can be considered that even for the same distribution of light diffusion points, fingerprints on the side with higher illuminance of the light emitted from the upper surface are more likely to be visually recognized. Considering these, referring to Figure 6B and Figure 7 , the following becomes clear.

[0087] In sample 2 where the size S of the gap between adjacent light diffusion points is 0.5 mm and 0.2 mm, it was determined that no fingerprints were visually recognized in all regions. In particular, even in region A with a high illuminance of 1560 Lx, no fingerprints were visually recognized. On the other hand, for example, in sample 4 where the size S of the gap is 0.7 mm, fingerprints were visually recognized in region A with an illuminance of 1300 Lx.

[0088] In region A where light is emitted with a high illuminance exceeding 1000 Lx, no fingerprints were visually recognized in sample 2 where the size S of the gap between adjacent light diffusion points is 0.5 mm and 0.2 mm, while fingerprints were visually recognized in sample 2 with a size of 0.7 mm. The reasons for this difference in the visual recognition of fingerprints are investigated below.

[0089] (Relationship between the size of the gap between adjacent light diffusion points and the visibility of fingerprints)

[0090] Next, referring to Figure 8A , 8B , 9A and 9B, the relationship between the size S of the gap between adjacent light diffusion points and the visibility of fingerprints is studied. Figure 8A is a side cross-sectional view for explaining the case where fingerprints attached to the surface portion in a shelf without light diffusion points are easily visually recognized. Figure 8B is a side cross-sectional view for explaining the case where fingerprints attached to the surface portion in a shelf with multiple light diffusion points arranged at a specified gap interval are not easily visually recognized. Figure 9A is a side cross-sectional view schematically showing the advancing mode of light when the size of the gap between adjacent light diffusion points is larger than the interval between the ridge lines of a human finger. Figure 9B is a side cross-sectional view schematically showing the advancing mode of light when the size of the gap between adjacent light diffusion points is less than or equal to the interval between the ridge lines (ridge) of a human finger. In the drawings, the cross-sectional shape of the ridge line that is substantially orthogonal to the extending direction of the ridge line is shown as a circle.

[0091] As Figure 8AAs shown, when fingerprints adhere to the surface portion of the shelf without light diffusion points, the surrounding light is reflected by the fingerprints, and this reflected light enters the eyes of the visual recognizer (refer to the solid arrows), thereby enabling the shape of the fingerprints to be recognized. In particular, when the light source is turned on and the light is guided to the shelf, the fingerprints are more easily visually recognized due to the shadow difference.

[0092] As Figure 8B shown, even on a shelf where a plurality of light diffusion points are arranged at a prescribed gap interval on the lower surface of the shelf, the surrounding light is reflected by the fingerprints, and this reflected light enters the eyes of the visual recognizer. In this shelf, furthermore, the surrounding light enters the shelf from the upper surface, is reflected by the light diffusion points, and is emitted upward from the upper surface (refer to the dashed arrows). Additionally, when the light source is turned on, the light from the light source is reflected by the light diffusion points and is emitted upward from the upper surface A (refer to the colored arrows).

[0093] Thus, the reflected light from the ridges of the fingerprints (refer to the solid arrows), the light reflected by the light diffusion points from the incident light from above (dashed arrows), and the light reflected by the light diffusion points from the light guided to the shelf (refer to the colored arrows) all enter the eyes of the visual recognizer. As a result, it becomes difficult to see the fingerprints.

[0094] Particular attention should be paid to the relationship between the interval of the ridges of the fingerprints and the interval of the light diffusion points.

[0095] As Figure 9A and Figure 9B shown, in the area where there are light diffusion points, the light is reflected by the light diffusion points and is emitted from the upper surface of the shelf, but in the space between the light diffusion points, no reflected light is generated. Thus, the larger the gap between adjacent light diffusion points, the wider the area where no reflected light is generated. As Figure 9A shown, when the size S of the gap between adjacent light diffusion points is greater than the interval T of the ridges of the finger, there may be no reflected light from the light diffusion points between the ridges. In such a space, the outer edge of the ridge formed by the reflected light of the ridge touched by the surrounding light becomes a state where it can be clearly visually recognized as it is.

[0096] On the other hand, as Figure 9B shown, when the size S of the gap between adjacent light diffusion points is less than or equal to the interval T of the ridges of the finger, there is no space where no reflected light from the light diffusion points is generated between the ridges. There must be reflected light from the light diffusion points in at least a part of the space between the ridges. The reflected light from the light diffusion points in the space between the ridges enters the eyes of the visual recognizer, so it is difficult to confirm the outer edge of the ridge formed by the reflected light of the ridge touched by the surrounding light.

[0097] The interval between the ridges of a fingerprint is generally considered to be 0.4 to 0.5 mm. Thus, in Sample 2 where the size S of the gap between adjacent light diffusion points is 0.5 mm and 0.2 mm, it is below the interval T of the ridges of a finger. Thus, even in the area A where light is emitted at an illuminance exceeding 1000 Lx, the fingerprint is not visually recognized. On the other hand, in the area A of Sample 4 where the size S of the gap is 0.7 mm, which is larger than the interval T of the ridges of a finger, the fingerprint is visually recognized in the area A where light is emitted at an illuminance exceeding 1000 Lx.

[0098] As described above, through Example 1, it was confirmed that when the size S of the gap between adjacent light diffusion points is below the interval of the ridges of a human finger, the fingerprint is not visually recognized even on the surface where light is emitted at an illuminance exceeding 1000 Lx. Specifically, it was confirmed that if the size S of the gap is 0.5 mm or less, the fingerprint cannot be visually recognized.

[0099] As described above, based on Example 1, the refrigerator 2 according to the embodiment of the present invention includes: a shelf 10 having translucency; a light source 20 that irradiates light from the side surface on the rear side of the shelf 10 toward the front side; and a plurality of light diffusion points 18 formed on at least one of the upper surface 10A and the lower surface 10B of the shelf 10, and the size S of the gap between adjacent light diffusion points 18 is below the interval of the ridges of a human finger.

[0100] Thus, it is possible to provide a refrigerator 2 having a shelf 10 that can illuminate the surface portions 10A and 10B and is less likely to be visually recognized even if fingerprints adhere to the surface portions 10A and 10B.

[0101] Furthermore, the light diffusion points 18 are substantially circular. If the diameter of the light diffusion point 18 is D, the distance between the centers of adjacent light diffusion points 18 is L, and the size of the gap is S, then S = L - D can be used for calculation.

[0102] By using substantially circular light diffusion points 18, it is possible to easily and efficiently arrange a plurality of light diffusion points 18 on the shelf 10 by printing or the like. Through the above formula S = L - D, the size S of the gap between adjacent light diffusion points 18 can be reliably set.

[0103] The interval between the ridges of a human finger is considered to be 0.4 to 0.5 mm. By setting S ≤ 0.5 mm, the size S of the gap between the light diffusion points 18 can be reliably set below the interval of the ridges of a human finger. Thus, it is possible to achieve a shelf that is less likely to be visually recognized even if fingerprints adhere to the surface portion. In addition, since there are individual differences in the interval of the ridges, it is more preferable to set S ≤ 0.4 mm, and further preferably set S ≤ 0.3 mm.

[0104] (Example 2)

[0105] Regarding the visual recognition test of fingerprints using the above-mentioned Samples 1 to 4, as Example 2, paying attention to the arrangement density of light diffusion points, confirmation was carried out on whether fingerprints could be visually recognized. Hereinafter, with reference to Figure 10 This situation will be described. Figure 10 It is a table showing the relationship between the arrangement density of light diffusion points and the visibility of fingerprints.

[0106] The arrangement density of light diffusion points is the ratio of the area occupied by light diffusion points in the entire area of the surface portion where light diffusion points are arranged. As described above, when the size S of the gap between adjacent light diffusion points is small, it can be considered that the arrangement density of light diffusion points becomes large, so there is a certain degree of correlation between the two. However, there are various dot patterns such as equilateral triangles and squares, and various combinations of the center distance between dots and the dot diameter. Therefore, the arrangement density of light diffusion points is not uniquely determined by the size of the gap between light diffusion points.

[0107] As Figure 10 shown, in the case of Sample 2 with an arrangement density of light diffusion points of 0.39, in all regions A to F, it was determined that no fingerprint was visually recognized. In particular, in region A where the illuminance from the upper surface exceeds 1000 Lx, it was also determined that no fingerprint was visually recognized.

[0108] Even when the arrangement density of light diffusion points is 0.39 or more, the size S of the gap between adjacent light diffusion points is not always less than the interval between the ridges of a human finger. However, in terms of probability, it can be said that there is a high possibility that reflected light from light diffusion points exists in the space between ridges. Therefore, it is difficult to confirm the outer edge of the ridge formed by the reflected light of the ridge touched by surrounding light, and it is considered difficult to visually recognize fingerprints.

[0109] As described above, based on Example 2, the refrigerator 2 according to the embodiment of the present invention includes: a shelf 10 having translucency; a light source 20 that irradiates light from the side surface 12 on the rear side of the shelf 10 toward the front side; and a plurality of light diffusion points 18 formed on at least one of the upper surface 10A or the lower surface 10B of the shelf 10, and the arrangement density of the light diffusion points 18 is 0.39 or more.

[0110] In this way, by making the arrangement density of the light diffusion points 18 0.39 or more, a shelf 10 can be realized that can illuminate the surface portions 10A and 10B of the shelf 10 and is reliably not easily visually recognized even when fingerprints adhere to the surface portions 10A and 10B. In addition, the structure shown in Example 2 can be combined with the structure shown in the above-mentioned Example 1.

[0111] (Example 3)

[0112] As Figure 7 shown in the table, when the illuminance from the upper surface of the shelf is less than 1000 Lx, even a light diffusion point that does not meet the requirements verified in the above-described Embodiments 1 and 2 may not allow fingerprints to be visually recognized. An illuminance of 1000 Lx is an illuminance level at which minute work can be performed. If one wants to confirm the state of the contents stored inside the refrigerator 2, even a lower illuminance will not pose a problem. For example, the recommended illuminance in the living area is 100 - 200 Lx.

[0113] Next, with reference to Figure 11 the configuration density of the light diffusion points where fingerprints are not visually recognized corresponding to the illuminance will be examined. Figure 11 is a graph showing the relationship between the illuminance of the surface portion of the shelf and the light diffusion point configuration density. In the Figure 11 graph, the horizontal axis represents the light diffusion point configuration density, and the vertical axis represents the illuminance (Lx) from the upper surface 10A.

[0114] From Figure 7 and Figure 10 the table and Figure 11 the graph, it is clearly known that when the illuminance from the upper surface 10A is 220 Lx or less, fingerprints are not visually recognized in all of the samples 1 - 4. The configuration density of the light diffusion points in this case is 0.15 or more. When the illuminance of the upper surface is 220 Lx or less, if the configuration density of the light diffusion points is 0.15 or more, the attached fingerprints cannot be visually recognized.

[0115] As described above, based on Embodiment 3, the refrigerator 3 according to the embodiment of the present invention includes: a shelf 10 having translucency; a light source 20 that irradiates light forward from the side surface 12 at the rear side of the shelf 10; and a plurality of light diffusion points 18 formed on at least one of the upper surface 10A or the lower surface 10B of the shelf 10. The illuminance of the surface 10A (10B) of the shelf 10 on the side opposite to the surface on which the light diffusion points 18 are arranged based on the light source 20 is 220 Lx or less, and the configuration density of the light diffusion points 18 is 0.15 or more.

[0116] Even when the illuminance is 220 Lx or less, it is sufficient to function as the illumination inside the refrigerator 2. It is possible to perform illumination from the surface portions 10A and 10B and limit the illuminance of the light emitted from the surface portions 10A and 10B, so that even with a smaller configuration density of the light diffusion points, fingerprints attached to the surface portions 10A and 10B cannot be visually recognized. In addition, the structure shown in Embodiment 3 can be combined with the structures shown in the above-described Embodiment 1 and / or Embodiment 2.

[0117] In addition, in the above-described Embodiments 1 to 3, a visual recognition test of the fingerprint on the upper surface 10A of the shelf 10 was performed, but it is not limited thereto. The same applies to the case where the light diffusion points 18 are provided on the upper surface 10A and a visual recognition test of the fingerprint on the opposite lower surface 10B is performed.

[0118] The embodiments and implementation states of the present invention have been described, but the disclosed content may also be changed in the details of the structure, and combinations and order changes of the elements in the embodiments and implementation states may be achieved without departing from the scope and spirit of the claimed invention.

Claims

1. A refrigerator, characterized in that, Comprising: A shelf having translucency; A light source that irradiates light from the side surface on the rear side of the shelf toward the front side; and A plurality of light diffusion points formed on at least one of the upper surface and the lower surface of the shelf, The size of the gap between adjacent ones of the light diffusion points being equal to or less than the interval between the ridge lines of a human finger.

2. The refrigerator according to claim 1, wherein The light diffusion points are substantially circular, If the diameter of the light diffusion point is set as D, The distance between the centers of adjacent ones of the light diffusion points is set as L, The size of the gap is set as S, Then there is a relationship of S = L - D.

3. The refrigerator according to claim 2, wherein There is a relationship of S ≤ 0.5 mm.

4. The refrigerator according to any one of claims 1 to 3, wherein The arrangement density of the light diffusion points is 0.39 or more.

5. A refrigerator, characterized in that, Comprising: A shelf having translucency; A light source that irradiates light from the side surface on the rear side of the shelf toward the front side; and A plurality of light diffusion points formed on at least one of the upper surface and the lower surface of the shelf, The arrangement density of the light diffusion points is 0.39 or more.

6. A refrigerator, characterized in that, Comprising: A shelf having translucency; A light source that irradiates light from the side surface on the rear side of the shelf toward the front side; And A plurality of light diffusion points formed on at least one of the upper surface and the lower surface of the shelf, The illuminance of the surface of the shelf on the side opposite to the surface where the light diffusion points are arranged based on the light source is 220 Lx or less, and the arrangement density of the light diffusion points is 0.15 or more.

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