KR20200024379A - Transparent display device - Google Patents

Abstract

The present invention relates to a transparent display device and, more specifically, to a transparent display device which can expand a visible area for the rear surface of a display by arranging a light guide plate having a non-spherical surface on the rear surface of a display panel. According to an embodiment of the present invention, the transparent display device comprises: a front glass allowing a display panel to be arranged on one surface thereof; a rear glass arranged to be spaced away from the front glass; a fixing member to fix a gap between the front glass and the rear glass; a light-scattering light guide plate which is arranged between the front glass and the rear glass, has a convex non-spherical surface towards the rear glass, and scatters light supplied thereinto; and a light source arranged on the edges of sides of the light-scattering light guide plate to supply light into the light-scattering light guide plate. According to the transparent display device, visibility for the rear surface of a display can be improved by arranging a light guide plate having a non-spherical surface on the rear surface of a display panel.

Description

Transparent display device {TRANSPARENT DISPLAY DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent display device, and more particularly, to a transparent display device having a light guide plate having an aspherical surface disposed on a rear surface of a display panel, so as to extend a viewing area of the rear surface of a display.

In general, the refrigerator is provided with a door that seals the inner space to prevent the cool air from leaking inside. As the door is installed, the inside of the refrigerator may be kept cool, and the freshness of the food stored in the refrigerator may be maintained. In particular, a transparent window may be formed on the refrigerator door so that the inside of the refrigerator can be easily recognized without opening or closing the refrigerator door.

The refrigerator door having a transparent window allows the user to easily view the inside of the refrigerator even when the refrigerator door is closed. Accordingly, it is possible to prevent the cool air inside the refrigerator from leaking to the outside by repeatedly opening and closing the refrigerator door.

Recently, a refrigerator door having a display provided on a refrigerator door having a transparent window and driving the display as needed or when the display is not driven, has been proposed.

However, in a refrigerator door provided with a conventional display, a light guide plate of a flat type is disposed on a rear surface of the display panel. The refrigerator door of such a structure has a limitation that visibility of the back surface of the area | region where a display is arrange | positioned is not good. Accordingly, there is a need for a display apparatus having a structure that can improve visibility of the rear surface of an area where a display is disposed.

1. Korean Patent Publication No. 10-2017-0132002 (name of the invention: a display device for a refrigerator door)

The present invention has been made to solve the above problems, the problem to be solved in the present invention, by placing a light guide plate having an aspherical surface on the back of the display panel, a transparent display device that can improve the visibility on the back of the display In providing.

The objects of the present invention are not limited to the above-mentioned objects, and other objects which are not mentioned will be clearly understood by those skilled in the art from the following description.

The transparent display device according to an embodiment of the present invention for solving the above problems, the front glass is disposed on the display panel; A rear glass spaced apart from the front glass; Fixing member for fixing between the front glass and the rear glass; A light scattering light guide plate disposed between the front glass and the rear glass and having an aspherical surface convex in the rear glass direction and configured to scatter light supplied therein; And a light source disposed around a side surface of the light scattering light guide plate to supply light to the inside of the light scattering light guide plate. It includes.

In addition, according to another feature of the invention, the fixing member is configured to form a closed space between the windshield and the rear glass, the light source and the light scattering light guide plate may be fixed by the fixing member.

In addition, according to another feature of the present invention, the aspherical surface may be symmetrical in at least one of the vertical direction or the left and right directions.

In addition, according to another feature of the present invention, the aspherical surface may be formed while the coordinate value Y corresponding to the thickness of the thickest portion satisfies the following Equation 1.

[Relationship 1]

이며, k는 -2<k<2 임.)(Where x is the coordinate value corresponding to the direction perpendicular to the thickness, c is the curvature of the aspherical surface, k is the conic constant, where c is

K is -2 <k <2.

In addition, according to another feature of the present invention, the light scattering light guide plate, a flat portion may be formed by a predetermined length from one end of the aspherical surface to one end of the light scattering light guide plate.

According to the transparent display device of the present invention, by providing a light guide plate having an aspherical surface on the back of the display panel, it is possible to provide a transparent display device that can improve the visibility on the back of the display.

1 is an exploded perspective view schematically illustrating a transparent display device according to an embodiment of the present invention.
2 is a cross-sectional view schematically illustrating a transparent display device according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view illustrating the structure of the light scattering light guide plate of FIG. 1.
4 is a view for explaining a change in viewing angle when the light scattering light guide plate of FIG. 1 is formed to have an aspherical surface.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms, and only the present embodiments make the disclosure of the present invention complete, and those of ordinary skill in the art to which the present invention belongs. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims.

References to elements or layers "on" other elements or layers include all instances where another layer or other element is directly over or in the middle of another element.

Although the first, second, etc. are used to describe various components, these components are of course not limited by these terms. These terms are only used to distinguish one component from another. Therefore, of course, the first component mentioned below may be the second component within the technical spirit of the present invention.

Like reference numerals refer to like elements throughout.

The size and thickness of each component shown in the drawings are shown for convenience of description, and the present invention is not necessarily limited to the size and thickness of the illustrated configuration.

Each of the features of the various embodiments of the present invention may be combined or combined with each other, partly or wholly, and various technically interlocking and driving are possible as one skilled in the art can fully understand, and each of the embodiments may be independently implemented with respect to each other. It may be possible to carry out together in an association.

Hereinafter, a transparent display device according to an exemplary embodiment will be described in detail with reference to FIGS. 1 to 4.

1 is an exploded perspective view schematically illustrating a transparent display device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view schematically showing a transparent display device according to an embodiment of the present invention, and FIG. 3 is FIG. 1. 4 is a cross-sectional view for describing the structure of the light scattering light guide plate of FIG. 1, and FIG. 4 is a view for explaining a change in viewing angle when the light scattering light guide plate of FIG. 1 is formed to have an aspherical surface.

Prior to the detailed description of the transparent display device, the transparent display device according to an embodiment of the present invention can be installed wherever the need to recognize the back of the device while driving the display. For example, the present invention can be applied to various places such as showcases and windows, as well as display stands for accessories and mobile phones. Hereinafter, for convenience of description, it will be described that the transparent display device of the present invention is installed in the door of the refrigerator.

1 and 2, the transparent display device 1000 of the present invention includes a front glass 100, a rear glass 200, a fixing member 300, a light scattering light guide plate 400, and a light source 500. .

The windshield 100 is disposed on the front surface of the transparent display device 1000 and functions to protect the front surface of the transparent display device 1000. Therefore, the windshield 100 may have a strength capable of protecting the entire surface of the transparent display device 1000, or a known glass formed of a transparent material may be used without limitation.

The windshield 100 may have a display panel (not shown) disposed on one surface thereof. Accordingly, the display panel can display an image to be visually visible from the outside. The display panel may be attached to one surface of the windshield 100 using an adhesive and a resin. One surface on which the display panel is disposed is preferably formed inside the apparatus 1000.

As the display panel, a transparent display panel is used, so that objects disposed on the rear surface of the transparent display apparatus 1000 can be easily recognized. For example, when the transparent display device 1000 is installed in the door of the refrigerator, the display image driven by the transparent display device 1000 can be visually recognized, and the state of the items stored in the refrigerator can be easily displayed. You can check it. The display panel may operate by receiving driving power from the outside.

A touch screen panel (not shown) may be disposed on a surface opposite to a surface on which the display panel is disposed on the windshield 100. The touch screen panel may receive a signal relating to an operation of the light source 500 or driving of the display, by sensing a touch signal of the user.

The rear glass 200 is formed to have an area corresponding to the windshield 100 and is spaced apart from the windshield 100. The rear glass 200 functions to insulate the inside and the outside of the transparent display device 1000. In this case, the low-emissivity glass may be used for the rear glass 200. Roy glass is a glass made of a thin coating of metal or metal oxide on the surface of the general glass, has a low emissivity and emissivity has an effective thermal insulation performance. Accordingly, when the Roy glass is used as the rear glass 200, condensation that may occur inside the transparent display device 1000 and cold air inside the refrigerator may be prevented from leaking to the outside. In addition to this, the rear glass 200 may be selected without limitation, known glass.

Fixing member 300 is disposed along the edge between the windshield 100 and the rear glass 200, is configured to form a closed space between the windshield 100 and the rear glass 200. The fixing member 300 fixes the light source 500 to be described later and the light scattering light guide plate 400 to be described later, so that the light source 500 can efficiently supply light toward the light scattering light guide plate 400. At this time, the fixing member 300 may be configured as a bar-shaped frame having a space formed therein, or may be configured in the form of a housing completely surrounding the edges of the windshield 100 and the rear glass 200.

The light scattering light guide plate 400 may be disposed between the windshield 100 and the rear glass 200. In addition, the light scattering light guide plate 400 is formed to have a convex aspherical surface 401 toward the rear glass 200, and may scatter light supplied from the light source 500 to be described later into the light scattering light guide plate 400.

The light scattering light guide plate 400 may be formed of a transparent material. In this case, the light scattering light guide plate 400 may be made of polymethylmethacrylate (PMMA), polycarbonate (PC) or glass (Glass) material of a transparent material having excellent light transmittance.

Referring to FIG. 2, the light scattering light guide plate 400 may include a transparent resin 410 and a light scattering agent 411 therein. Here, the transparent resin 410 may be a transparent liquid UV curable resin, the light scattering agent 411 may be composed of an inorganic material and an organic material.

Specifically, the inorganic material configured in the light scattering agent 411 may include one selected from titanium dioxide (TiO 2), silica (SiO 2), and aluminum oxide (Al 2 O 3). When such an inorganic material is included in the light scattering agent 411, the light output efficiency is improved by reflecting light from the light source 500 with a high reflectance. At this time, the inorganic material is preferably mixed in a ratio of 10% by weight or less relative to the total weight of the transparent resin (410). When the inorganic material is mixed at a ratio of more than 10% by weight relative to the total weight of the transparent resin 410, the light output efficiency may be further improved, but the light transmittance is lowered, so that visibility of the inside and outside of the transparent display apparatus 1000 may be improved. Can be degraded.

In addition, the organic material included in the light scattering agent 411 may include polystyrene (PS) or poly methyl methacrylate (PMMA). When the organic material is included in the light scattering agent 411, the refractive index of the light scattering light guide plate 400 may be controlled. However, when the light scattering agent 411 is included in a large amount, the light emission efficiency of the light scattering light guide plate 400 may be inhibited. Therefore, the organic material is preferably mixed at a ratio of less than 5% by weight based on the total weight of the transparent resin 410.

On the other hand, the light scattering agent 411 is preferably composed of particles having a diameter smaller than the wavelength of visible light.

Specifically, the inorganic material may be composed of particles having a diameter of 10nm to 500nm. When the inorganic material has a diameter smaller than 10 nm, the light transmittance may be improved, but the light emission efficiency may be reduced. On the other hand, when the inorganic material has a diameter larger than 500 nm, the light emission efficiency may be improved, but the light transmittance may be lowered.

In addition, the organic material may be composed of particles having a diameter of 80nm to 300nm. When the organic material has a diameter smaller than 80 nm, light transmittance may be improved, but light emission efficiency may be reduced. On the other hand, when the organic material has a diameter larger than 300 nm, the light emission efficiency may be improved but the light transmittance may be reduced.

As such, as the light scattering light guide plate 400 includes the light scattering agent 411, the light scattering light guide plate 400 may transmit light or function as a surface light source by an operation of the light source 500 to be described later. Specifically, the light scattering light guide plate 400 allows the driving image of the display panel to be displayed when light is supplied from the light source 500, and when light is not supplied to the light scattering light guide plate 400, the front surface of the light scattering light guide plate 400 is provided. In order to transmit light, the rear surface of the transparent display apparatus 1000, that is, the inside of the refrigerator may be visually recognized.

Referring back to FIGS. 1 and 2, the light scattering light guide plate 400 may have an aspherical surface 401 toward one end from a central portion thereof. In this case, the aspherical surface 401 may be formed to be symmetrical in at least one of up and down directions or left and right directions. For example, the aspherical surface 401 may be formed toward the upper side and the lower side from the center of the light scattering light guide plate 400, respectively, may be formed toward the left and right from the center of the light scattering light guide plate 400, respectively, the upper side, the lower side It may be formed toward both left and right sides.

The aspherical surface 401 may be formed while the coordinate value Y corresponding to the thickness of the thickest portion satisfies the following relational expression (1).

[Relationship 1]

이이며, k의 값은 -2<k<2 이다.Here, x is a coordinate value corresponding to the plane perpendicular | vertical to thickness. For example, assuming that the true center of the light scattering light guide plate 400 is the origin of the coordinates, the Y value is a coordinate value corresponding to the thickest portion of the aspherical surface 401 in the convex direction, and the x value is an aspherical surface 401. Coordinate value corresponding to the direction perpendicular to the convex direction. Here, the direction perpendicular to the direction in which the aspherical surface 401 is convex may mean an up and down direction of the light scattering light guide plate 400 according to a direction in which the aspherical surface 401 is formed on the light scattering light guide plate 400, and may mean a left and right direction. It may be. In addition, c is the curvature of the aspherical surface 401 and k is a conic constant. At this time, the value of c is

This value of k is -2 <k <2.

As such, when the light scattering light guide plate 400 is formed to have a convex aspherical surface 401 toward the rear glass 200, the light spreading area is increased to improve visibility of the inside of the refrigerator.

2 and 4, the viewing angle (b) when the light scattering light guide plate 400 is formed to have an aspherical surface 401 is larger than the viewing angle (a) when the light scattering light guide plate 400 is formed in a plane. Can be formed. Accordingly, the light supplied into the light scattering light guide plate 400 is changed by the aspherical surface 401, and the refracted light spreads to a wider area, thereby allowing the inside of the refrigerator to be more easily recognized.

Meanwhile, the planar portion 402 may be formed in the light scattering light guide plate 400. The planar portion 402 is formed to have a predetermined length from one end of the aspherical surface 401 to one end of the light scattering light guide plate 400, so that the spacer 600 to be described later may be disposed.

The light source 500 is disposed at the periphery of the light scattering light guide plate 400 to supply light to the inside of the light scattering light guide plate 400.

Referring to FIG. 1, the light source 500 may be disposed around the side surface of the light scattering light guide plate 400 to supply light to the inside of the light scattering light guide plate 400. For example, the light source 500 may be disposed above or below the light scattering light guide plate 400, and may be disposed on the left side or the right side. When the light source 500 is disposed at this position, a separate frame (not shown) may be provided to fix the light source 500 disposed at the corresponding position. In addition, when the aspherical surface 401 of the light scattering light guide plate 400 is formed to be symmetric in the vertical direction and the left and right directions, the light source 500 may be disposed around all of the light scattering light guide plates 400.

The light source 500 may be configured of light emitting members such as a light emitting diode (LED), a hot cathode fluorescent lamp (HCFL), a cold cathode fluorescent lamp (CCFL), and an external electrode fluorescent lamp (EEFL). It may also be configured in the form of a mounted array.

In addition, the transparent display apparatus 1000 may further include a spacer 600.

Spacer 600 may be disposed in planar portion 402. In detail, the spacer 600 may be disposed between the rear glass 200 and the light scattering light guide plate 400 or between the fixing member 300 and the light scattering light guide plate 400. Accordingly, the spacer 600 allows the light scattering light guide plate 400 and the structure in contact with the light guide plate 400 to be disposed at regular intervals, and may be fixed between the structures.

The spacer 600 may be configured to include a moisture absorbent therein to remove moisture in the transparent display device 1000. In addition, the spacer 600 is configured to include a structure such as a butyl material and a sealant at the edge, so that it can be firmly fixed between the light scattering light guide plate 400 and the structure in contact with it.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. I can understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

1000... Transparent display device
100... Windshield
200... Rear glass
300... Fixing member
400... Light Scattering Light Guide Plate
401... Aspheric surface
402. Flat part
410... Transparent resin
411. Light scattering agent
500... Light source
600... Spacer

Claims (5)

A front glass on which a display panel is disposed;
A rear glass spaced apart from the front glass;
Fixing member for fixing between the front glass and the rear glass;
A light scattering light guide plate disposed between the front glass and the rear glass and having an aspherical surface convex toward the rear glass and configured to scatter light supplied therein; And
A light source disposed around a side surface of the light scattering light guide plate to supply light to the inside of the light scattering light guide plate; Transparent display device comprising a. According to claim 1,
The fixing member is configured to form a closed space between the windshield and the rear glass,
And the light source and the light scattering light guide plate are fixed by the fixing member. According to claim 1,
The aspherical surface,
A transparent display device which is symmetrical in at least one of vertical and horizontal directions. According to claim 1,
The aspherical surface,
The coordinate display Y corresponding to the thickness of the thickest portion is formed while satisfying the following relational expression 1.
[Relationship 1]

(Where x is the coordinate value corresponding to the direction perpendicular to the thickness, c is the curvature of the aspherical surface, k is the conic constant, where c is

K is -2 <k <2. According to claim 1,
The light scattering light guide plate,
The flat display portion is formed by a predetermined length from one end of the aspherical surface to one end of the light scattering light guide plate.

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