JP2021165823A - Display panel - Google Patents

Abstract

To provide a display panel capable of improving the visibility at light emission and thinning a device.SOLUTION: A display panel includes a light-emitting element array substrate where light-emitting elements are arranged two-dimensionally, a transparent base material forming a waveguide in an optical axis direction of the light-emitting element, and a non-transparent thin layer covering an emission surface of the transparent base material. The transparent base material includes a pore in a resin base material formed of the transparent resin. The pore is formed of a lattice-shaped louver. The space of the lattice-shaped louver may become a waveguide along an optical axis of the light-emitting element arranged on the light-emitting element array substrate. The pore may be provided to the resin base material formed of transparent resin and the pore may be filled with a light-transmitting material whose refractive index is different from that of the resin base material. In addition, the transparent base material may be formed of at least two louver films that are stacked with their louvers orthogonal to each other or may be formed of an aggregation of fine fibers.SELECTED DRAWING: Figure 1

Description

The present invention relates to a display panel used for a controller of a household electric appliance, a display of an electronic device, a mobile body such as an automobile, or the like.

In recent years, information and communication technology has undergone remarkable evolution. In the past, personal computers were used only in limited spaces such as homes and offices, but with the spread of smartphones and tablet terminals, anyone can now live a highly convenient life using the Internet, etc. You can do it. In addition, from the viewpoint of IoT (Internet of Things), new products using the Internet are being developed one after another for home appliances and the like that were not conventionally connected to the Internet. In this way, the Internet and products using the Internet have already become indispensable to people's lives, and such products are installed or carried everywhere and used by many people. Has been done.
However, while all kinds of devices are around us, we can enjoy a convenient life, but many people are stressed by living surrounded by electronic devices.

For example, a hotel that values the warmth of natural wood can be said to be a high-quality space where guests can forget about work and relax. However, if a large number of electronic devices, displays or controllers in an inorganic form are placed in such a guest room, it becomes impossible to forget the daily life and relax sufficiently.

Therefore, there is known an operation display panel embedded article in which a thin layer made of wood or the like covers the entire front surface of a display panel with a touch sensor incorporated in the outer peripheral surface of the housing and is arranged on the outer peripheral surface of the housing. (See Patent Document 1). This is designed so that the thickness of the thin layer and the brightness of the panel make the content displayed on the panel visible, and according to such technology, even an article incorporating an operation display panel. It naturally harmonizes with the space and does not cause visual noise for the user, and when the user wants to use it or when it is necessary, it is possible to operate it intuitively while feeling the feel of natural materials.

Then, in the article incorporated in the operation display panel of Patent Document 1, in order to improve the visibility at the time of display, a light guide for guiding the light emitting direction of the light emitting element is provided between the transparent conductive sheet and the light emitting element array. It is supposed to be provided. The light guide here is an opaque dark-colored base material laminated on the substrate of the light-emitting element array, which encloses the entire light-emitting element array and is provided with through holes along the optical axis of each light-emitting element. Pointing to. By providing through holes along the optical axis of each light emitting element in this way, it is possible to improve visibility at the time of light emission.
However, in the case of a method of improving visibility at the time of light emission using a light guide, the light guide needs to have a certain thickness in order to guide the light emitting direction of the light emitting element, so the thickness should be reduced. There is a problem that it is difficult. Further, when the light guide is provided, there is a problem that the alignment of the light emitting element and the light guide is required, which increases the manufacturing cost, the cost of the light guide when the screen becomes large, and the problem of strength and rigidity. ..
Further, in the case of a display panel that does not perform a touch operation, the transparent conductive sheet is not used, and there is room for further thinning, but the operation display panel built-in article of Patent Document 1 does not perform a touch operation. No mention is made of the case of the display panel.

Japanese Patent No. 6370519

In view of such a situation, it is an object of the present invention to provide a display panel capable of improving visibility at the time of light emission and reducing the thickness of the device.

In order to solve the above problems, in the display panel of the present invention, light emitting elements are arranged two-dimensionally, and a light emitting element array substrate in which a striking wall portion is not provided between the light emitting elements and a light emitting element array substrate are guided in the optical axis direction of the light emitting elements. It includes a transparent base material that forms an optical path and an opaque thin layer that covers the exit surface of the transparent base material, and does not have a transparent conductive film.
By providing a transparent base material that forms a light guide path in the optical axis direction of the light emitting element, the light of the light emitting element can be efficiently traveled straight. As a result, the loss of light is reduced, the amount of light when displayed on a thin layer is increased, and the display performance can be improved. In addition, effects such as cost reduction and miniaturization of light emitting element components, power consumption and suppression of heat generation can be obtained. Further, the miniaturization of the light emitting element component contributes to the high density of pixels. Further, unlike the light guide of the prior art, it is not necessary to align the light emitting element and the transparent base material, so that the manufacturing cost can be reduced.
Here, opaque means that visible light is substantially not transmitted, and in the present specification, opacity means that the visible light transmittance is less than 20%. The opaque thin layer is a thin layer having a visible light transmittance of less than 20%, and the transmittance is determined from the material and thickness of the thin layer. The opaque thin layer has a light emitting element array substrate in which light emitting elements are two-dimensionally arranged on the back side thereof, and the irradiation light from the light emitting element passes through the thin layer, and the presence of the light emitting element is clarified from the front side of the thin layer. It is recognizable. The opaque thin layer has opacity to the extent that the presence of an object on the back side of the blank paper cannot be detected by the reflected light under normal lighting, such as a blank paper such as memo paper, but the light source is on the back side of the blank paper. Then, the irradiation light from the light source passes through the blank paper, and the existence of the light source can be clearly recognized from the front side of the blank paper. The material of the thin layer and the thickness of the layer are designed so that the thickness of the opaque thin layer and the brightness of the light emitting element can visually recognize the content displayed on the thin layer.
As will be described later, the opaque thin layer is a natural wood, natural fiber, natural leather or natural stone, or a resin, synthetic fiber, or synthetic material produced by imitating the appearance and texture of nature. It is preferably composed of leather or artificial stone, but is not limited to these. The opaque thin layer may be a thin layer made of an artificial material that is not of natural origin, or may not be a material produced by imitating the appearance and texture of nature.

In the display panel of the present invention, in the transparent base material, micropores are provided in a resin base material made of a transparent resin, the micropores are formed by lattice-shaped louvers, and gaps between the grid-shaped louvers are formed in a light emitting element. It may be a light guide path along the optical axis of the light emitting elements arranged on the array substrate. Since the micropores are formed by the lattice-shaped louvers, the light of the light emitting element can be efficiently traveled straight, and the display performance can be improved. Further, the transparent base material may be a resin base material made of a transparent resin provided with fine pores, and the fine pores may be filled with a translucent material having a refractive index different from that of the resin base material.
As a resin base material made of a transparent resin provided with micropores formed by lattice-shaped louvers, or as a transparent base material in which the fine pores provided in the resin base material are filled with a translucent material. A known privacy filter is preferably used.
In the present specification, the shape of the micropores is not particularly limited, and may be not only a circular hole in a plan view but also a polygonal shape such as a hexagon in a plan view.

In the display panel of the present invention, the transparent base material may be made by laminating at least two louver films so that the louvers are orthogonal to each other. By laminating a plurality of louver films, the light of the light emitting element can be efficiently traveled straight at low cost even when a grid-like louver is not used, and the display performance is improved.

In the display panel of the present invention, the transparent substrate may consist of an aggregate of fine fibers. Since the transparent base material is made of an aggregate of fine fibers, the light of the light emitting element can be efficiently traveled straight, and the display performance can be improved.

In the display panel of the present invention, the fine fiber can be widely used such as an optical fiber and ulexite, but an optical fiber made of glass or plastic is preferable. In the case of the above-mentioned fine pores, the amount of light that is absorbed in the pores and reaches the surface decreases, but in the case of fine fibers such as optical fibers, the light absorption is suppressed because the light is totally reflected, and the amount of light that reaches the surface. Has the advantage of increasing.

In the display panel of the present invention, the transparent base material may be formed of a flexible resin. By forming the transparent base material with a flexible resin, it is possible to manufacture display panels having various shapes. As for the shape, for example, it is possible to manufacture a display having a curved surface. The molding method can be realized by processing a transparent base material using a molding technique such as insert molding or in-mold molding.

In the display panel of the present invention, the transparent base material preferably has a visible light transmittance of 50% or more.

In the display panel of the present invention, the thin layer is made of naturally derived wood, natural fiber, natural leather or natural stone, or resin, synthetic fiber, synthetic leather or a material produced by imitating the appearance and texture of nature. It is preferably made of artificial stone.
By using a material derived from nature or a material generated by imitating the appearance and feel of nature, a natural feel can be realized. Therefore, a polymer material such as a resin can be used as the thin layer material as long as it realizes a natural appearance and a natural feel. Since the resin is easy to mold, it has an advantage that a thin layer having a three-dimensionally complicated shape can be produced. Here, the polymer material refers to a material having a large molecular weight, and refers to a polymer obtained by polymerizing a monomer or a compound having a large molecular weight such as a natural polymer.

According to the display panel of the present invention, there are effects that visibility at the time of light emission is improved and the device is made thinner. In addition, there is no need to align the light emitting element and the light guide, it is easy to support curved displays, and unlike the resin molded light guide, it is easy to handle various screen sizes and pixel spacing. There is.

Schematic cross-sectional view of the display panel of Example 1 Operation display panel of the conventional technology Configuration image diagram of the built-in article Schematic cross-sectional view of the article incorporated in the operation display panel of the prior art

Hereinafter, an example of the embodiment of the present invention will be described in detail with reference to the drawings. The scope of the present invention is not limited to the following examples and illustrated examples, and many modifications and modifications can be made.

First, in explaining the embodiment of the present invention, the basic configuration of the article incorporating the operation display panel using the display panel of the prior art will be described.
FIG. 2 shows a configuration image diagram of an article incorporated in the operation display panel of the prior art. As shown in FIG. 2, the operation display panel built-in article 105 is composed of a veneer 2, a transparent base material 3, a touch panel sheet 4 as a transparent conductive film, a light guide 5, and an LED array 6 as a light emitting element array, respectively, from above. They are stacked in order. The veneer 2 using the sycamore material is located on the outer surface of the article incorporated in the operation display panel, and the LED array 6 is configured to be located inside the article. A large number of LED light sources 7 are arranged two-dimensionally in the LED array 6. The light guide 5 guides the light emission direction of each LED light source 7 in the direction perpendicular to the substrate of the LED array 6, and is provided with the same number of guide holes 5a as the number of LED light sources 7.

Although not all LED light sources are shown in FIG. 2 for convenience of explanation, for example, the LED array 6 is composed of a total of 6400 LED light sources of 32 vertical and 200 horizontal. One LED light source is composed of a plane mount type LED. A point light source can be realized by the light of one LED light source, and this can be regarded as one dot, and one character or pattern can be expressed by 8 × 8 dots or 16 × 16 dots. For example, in the case of the LED array 6 having 6400 LED light sources, a sentence of 22 characters × 3 lines can be expressed. Here, as the LED light source, for example, an LED light source having a size of 2 mm × 2 mm and 700 to 1000 mcd (millicandela) is used.
The light guide 5 is a dark-colored base material, and plays a role of clearly visualizing characters and patterns composed of light emitted from the LED light source 7 through the veneer 2. That is, a large number of guide holes 5a are arranged according to the arrangement of the LED light sources 7 so that the guide holes 5a are arranged directly above each LED light source 7 when the light guides 5 are laminated on the LED array 6. Is provided.

Next, the structure of the article incorporated in the operation display panel using the display panel of the prior art after assembly will be described with reference to FIG.
FIG. 3 shows a schematic cross-sectional view of an article incorporated in the operation display panel of the prior art. As shown in FIG. 3, in the operation display panel built-in article 105, the veneer 2, the transparent base material 3, the touch panel sheet 4, the light guide 5, and the LED array 6 are laminated in order from the top by the housing 8. It is glued. Of the light emitted from the LED light source 7 provided on the LED array 6, the obliquely emitted light (90b, 90c) is blocked by the light guide 5, and is a veneer as straight light like the light 90a. It will reach 2. The housing 8 is mainly made of ABS resin.
The veneer 2 and the transparent base material 3 or the transparent base material 3 and the touch panel sheet 4 are bonded together without providing a gap. In contrast, between the touch panel sheet 4 and the light guide 5, a gap G ₁ is provided. This is because the light guide 5 is provided with a guide hole 5a, and when the touch panel sheet 4 and the light guide 5 are adhered to each other, the stress varies when the touch panel is operated, which causes a malfunction. be.

Further, even while the light guide 5 and the LED light source 7, the gap _{G 2} is provided. Since the number of the LED light source 7 provided in the LED array 6 and the guide holes 5a provided in the light guide 5 reaches several thousand, there is an arrangement error when the light guide 5 and the LED array 6 are laminated. It can occur. If the light guide 5 and the LED array 6 are adhered to each other in a state where an error occurs, the light emitted from the LED light source 7 does not pass through the guide hole 5a, and accurate display cannot be performed. Therefore, _{by providing the gap G 2} , it is possible to prevent the display quality from being deteriorated due to an error in the arrangement of the LED light source 7 and the guide hole 5a. Moreover, since the display quality is maintained even if there are some errors, the manufacturing becomes easy.
Hereinafter, the display panel of the present invention will be described. The display panel described in the following embodiment can be incorporated in the housing 8 as shown in FIG.

FIG. 1 shows a schematic cross-sectional view of the display panel of the first embodiment. As shown in FIG. 1, in the display panel 101, unlike the operation display panel built-in article 105 of the prior art, the transparent base material 30 is provided instead of the transparent base material 3. A large number of micropores are formed as guide holes 30a in the transparent base material 30 which is a resin base material made of a transparent resin. Although not shown, the guide hole 30a is formed by a grid-shaped louver, and the gap between the grid-shaped louvers serves as a light guide path along the optical axis of the LED light source 7. Alternatively, the guide hole 30a is filled with a translucent material having a refractive index different from that of the main body of the transparent base material 30, so that the guide hole 30a serves as a light guide path for the emitted light of the LED light source 7.
That is, the light 9a emitted from the LED light source 7 can efficiently travel straight through the guide hole 30a as the light 9b as it is. As a result, the loss of light is reduced, the amount of light when displayed on a thin layer is increased, and the display performance can be improved. Further, by not providing the light guide 5, the gap between the LED light source 7 and the transparent base material 30 can be further reduced, and the space between the LED light source 7 and the light guide 5 in the conventional configuration shown in FIG. 3 and the space between the light guide 5 and the light guide 5 can be further reduced. It has the effect of suppressing the diffusion of light in the gap between the light guide 5 and the transparent base material 3. Further, by not providing the light guide 5, it is possible to reduce the cost and the thickness. Since the veneer 2 is made of sycamore material, it is possible to realize a clear display and a soft appearance display in which the warmth of the natural material can be felt.
As the thickness of the transparent base material 30, various thicknesses can be adopted according to the needs. For example, if it is desired to increase the rigidity of the transparent base material 30, the transparent base material 30 may be made thicker, or the transparent base material 30 may be made thinner in order to reduce the thickness of the device.

(Other Examples)
1) The transparent base material 30 may be made by laminating at least two louver films so that the louvers are orthogonal to each other. By laminating a plurality of louver films, the light of the light emitting element can be efficiently traveled straight at low cost even when a grid-like louver is not used, and the display performance is improved.
2) The transparent base material 30 may be made of a glass or plastic optical fiber or an aggregate of fine fibers such as ulexite. In the case of fine pores, the amount of light that is absorbed in the pores and reaches the surface decreases, but in the case of fine fibers such as optical fibers, the absorption of light is suppressed because the light is totally reflected, and the amount of light that reaches the surface increases. There is an advantage to do.

The present invention is used for display devices for household electric appliances, displays for electronic devices, display devices mounted on moving bodies such as automobiles, or display devices provided in structures such as interiors and exteriors of houses and buildings. It is useful as a display panel.

2 Veneer 3,30 Transparent base material 4 Touch panel sheet 5 Light guide 5a, 30a Guide hole 6 LED array 7 LED light source 8 Housing 9a, 9b, 90a to 90c Light 101 Display panel 105 Operation display panel Built-in article G gap

Claims (9)

A light emitting element array substrate in which light emitting elements are arranged two-dimensionally and no striking wall portion is provided between the light emitting elements, and a light emitting element array substrate.
A transparent base material that forms a light guide path in the optical axis direction of the light emitting element,
An opaque thin layer that covers the exit surface of the transparent substrate,
Display panel with no transparent conductive film. In the transparent base material, micropores are provided in a resin base material made of a transparent resin, the micropores are formed by lattice-shaped louvers, and gaps between the grid-shaped louvers are arranged on the light emitting element array substrate. The display panel according to claim 1, wherein the light guide path is along the optical axis of the light emitting element. The transparent base material is characterized in that a resin base material made of a transparent resin is provided with micropores, and the micropores are filled with a translucent material having a refractive index different from that of the resin base material. The display panel according to claim 1. The display panel according to claim 1, wherein the transparent base material is formed by laminating at least two louver films so that the louvers are orthogonal to each other. The display panel according to claim 1, wherein the transparent base material is made of an aggregate of fine fibers. The display panel according to claim 5, wherein the fine fibers are optical fibers made of glass or plastic. The display panel according to any one of claims 1 to 6, wherein the transparent base material is formed of a flexible resin. The display panel according to any one of claims 1 to 7, wherein the transparent base material has a visible light transmittance of 50% or more. The thin layer consists of naturally occurring wood, natural fibers, natural leather or natural stone, or resin, synthetic fibers, synthetic leather or artificial stone, which is a material produced by imitating the appearance and feel of nature. The display panel according to any one of claims 1 to 8, which is characterized.

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