WO2014119846A1

WO2014119846A1 - Transparent display device

Info

Publication number: WO2014119846A1
Application number: PCT/KR2013/012004
Authority: WO
Inventors: 안기환; 김병인
Original assignee: 동우화인켐 주식회사
Priority date: 2013-02-01
Filing date: 2013-12-23
Publication date: 2014-08-07
Also published as: KR20140099064A; TW201432307A

Abstract

The present invention relates to a transparent display device and, more specifically, to a transparent display device capable of implementing a black mode by comprising: an image display unit provided with a transparent OLED; and a light interruption unit bonded with at least one side of the image display unit, and provided with a light absorbent of which the arrangement thereof is changed according to an electric field or a magnetic field such that the light interruption unit is turned on or off according to the application of the electric field or the magnetic field.

Description

Transparent display device

The present invention relates to a transparent display device, and more particularly, to a transparent display device capable of implementing a black mode.

BACKGROUND ART Image display apparatuses, which are mainly dominated by conventional CRT monitors, have recently undergone rapid advances in technology, such as liquid crystal displays (LCDs), field emission displays (FEDs), and plasma displays (PDPs). Flat panel display devices such as a panel (OLED) and an organic light emitting diode (OLED) are being developed, and image display devices that can be bent, such as electronic paper, are being introduced one after another.

Among these, the organic electroluminescent device (hereinafter referred to as 'OLED') is formed by combining electrons injected from an electron injection electrode (cathode electrode) and holes injected from a hole injection electrode (anode electrode) in the light emitting layer. It is a self-luminous device that forms an exciton and emits light while emitting excitons.

Due to this principle, unlike LCD, which is conventionally used as a thin display device, it does not need a separate light source, and thus has the advantage of reducing the volume and weight of the device. Since the reaction speed is 1000 times faster than LCD, afterimage display is performed. As a result, it is emerging as a next-generation display device.

OLEDs can be classified into passive matrix OLEDs (PM-OLED) and active matrix OLEDs (AM-OLED). PM-OLED is a simple structure that emits light in a region where two electrodes cross each other, and AM-OLED is a structure in which current is driven by each pixel by a thin film transistor (TFT) to emit light. The AM-OLED is divided into a bottom emission structure that emits light toward the substrate on which the thin film transistor is formed, and a top emission structure that emits toward the opposite side of the substrate on which the thin film transistor is formed, according to the light emitting structure. Can be.

In addition, if both the cathode and the anode of the OLED are composed of transparent electrodes, and the driving thin film transistor is composed of an optically transparent material, or the area occupied by the driving thin film transistor in the pixel composed of the driving thin film transistor and the OLED is reduced, It is also possible to manufacture transparent AM-OLEDs that emit light to display information on both sides of the substrate.

However, when implementing a transparent display device using transparent AM-OLED, since the transparent AM-OLED is always configured to transmit external light, it cannot express the black mode in which the transmitted light must be completely blocked. There is this. In addition, there is a problem in that visibility is sharply degraded in the outdoor with a large amount of light due to reflection of external light.

In order to solve this problem, Korean Patent Publication No. 2012-0106432 proposes a transparent display device having a cholesteric liquid crystal based blind panel under the image display unit, and Korean Patent Publication No. 2009-0100920 discloses a TFT-LCD. The transparent display device which laminated | stacked the light quantity control part which consists of a light emitting part which consists of transparent OLED was proposed.

However, all of the above techniques are intended to implement a black mode using liquid crystals, which inevitably causes a slope light leakage phenomenon according to a viewing angle of a viewer having a conventional LCD display.

[Preceding technical literature

[Patent Documents]

(Patent Document 1) Patent Document 1: Korean Patent Publication No. 2012-0106432

(Patent Document 2) Patent Document 2: Korea Patent Publication No. 2009-0100920

An object of the present invention is to provide a transparent display device capable of implementing a black mode.

1. An image display unit having a transparent OLED; And a light blocking unit bonded to at least one surface of the image display unit and having a light absorbing agent whose arrangement is changed according to an electric field or a magnetic field, and being turned on or off by application of an electric field or a magnetic field.

2. In the above 1, wherein the light blocking unit is provided with a light absorbing agent including a magnetic material is turned on-off according to the application of a magnetic field.

3. In the above 2, the light blocking unit is on-off using the electromagnet system transparent display device.

4. In the above 2, wherein the light absorbing agent is at least one of a magnetic material alone, and a magnetic material coated with an organic material or an inorganic material.

5. The transparent display device of 2 above, wherein the magnetic material has a superparamagnetic property.

6. The transparent display device of any one of 2, 4, and 5, wherein the magnetic material includes at least one oxide selected from the group consisting of Fe, Co, Ni, and FePt.

7. The transparent display device of any one of 2, 4 and 5, wherein the magnetic material has a size of 1 to 100 nm.

8. In the above 1, wherein the light blocking portion has one end is fixed to the inner wall of the light blocking portion and has a body that can be bent and provided with a light absorber capable of holding a charge transparent on-off upon application of an electric field Display device.

9. The transparent display device of claim 8, wherein the light blocking unit applies an electric field by generating a potential difference on both sides of the light blocking unit.

10. In the above 8, wherein the light absorber is arranged in the thickness direction of the light blocking unit when an electric field is applied.

11. The transparent display device of 2 or 8, wherein the light blocking unit is disposed at at least one of a front side and a rear side of the image display unit.

12. The transparent display device of 2 or 8, wherein when the image display unit and the light blocking unit are turned on, external light is transmitted through the light blocking unit, and an image is displayed on the front and the rear of the image display unit.

13. The transparent display device of 2 or 8, wherein when the image display unit and the light blocking unit are in an off state, external light is blocked through the light blocking unit, and black is displayed as the image display unit does not display an image.

14. The transparent display device of 2 or 8, wherein when the image display unit is on and the light blocking unit is off, external light is blocked through the light blocking unit, and an image is displayed on the front or the rear of the image display unit.

15. The transparent display device as set forth in 2 or 8, wherein a polarizing plate is provided on an opposite side of the light blocking unit of the image display unit.

The transparent display device of the present invention can implement a black mode by completely blocking the light transmitted through the light blocking unit having the magnetic material.

In addition, the transparent display device of the present invention is driven by simply turning on and off the light blocking unit, so driving of the black mode is very easy.

In addition, the transparent display device of the present invention can be utilized as a transparent display device that can view information on both sides and a single-side display device that can only view information on one surface by simply turning on and off the light blocking unit.

In addition, the transparent display device of the present invention may further improve the viewing feeling by further comprising a polarizing plate on the opposite side of the light blocking portion of the image display unit.

1 is a schematic vertical cross-sectional view of an embodiment of a transparent display device of the present invention.

2 is a schematic vertical cross-sectional view of an embodiment of the transparent display device of the present invention.

3 is a schematic vertical cross-sectional view of the case where a magnetic material is coated among light absorbers used in the transparent display device of the present invention.

4 is a schematic vertical cross-sectional view of another embodiment of the transparent display device of the present invention.

The present invention provides an image display unit having a transparent OLED; And a light blocking unit bonded to at least one surface of the image display unit and having a light absorbing agent whose arrangement is changed according to an electric field or a magnetic field and turned on or off according to an application of an electric field or a magnetic field. The present invention relates to a transparent display device.

Hereinafter, the present invention will be described in more detail with reference to the drawings. However, the following drawings attached to the present specification are intended to illustrate preferred embodiments of the present invention, and together with the contents of the present invention serves to further understand the technical spirit of the present invention, the present invention described in such drawings It should not be construed as limited to matters.

1 is a vertical cross-sectional view of an embodiment of a transparent display device of the present invention.

The transparent display device of the present invention includes an image display unit 100 and a light blocking unit 110.

The image display unit 100 according to the present invention includes a plurality of organic electroluminescent devices (OLEDs) that are two-dimensionally arranged on a transparent substrate to display an image. Transparent OLEDs are driven in thin film transistors (TFTs), and this configuration and operation can be adopted without limitation as commonly used in the art.

The light blocking unit 110 according to the present invention is provided on at least one surface of the image display unit 100, that is, at least one surface of the front and rear surfaces.

The light blocking unit 110 includes a light absorber whose arrangement is changed according to an electric field or a magnetic field, and is turned on or off in response to the application of the electric or magnetic field. The black mode may be implemented when the light blocking unit 110 is in an off state, and the transparent mode may be implemented when the light blocking unit 110 is in an off state.

The on-off of the light blocking unit 110 may be determined according to the application of an electric field or a magnetic field. Hereinafter, each case will be described in detail with reference to the accompanying drawings.

2, as an embodiment of the present invention, a schematic structure of a light blocking unit 110 including a light absorbing agent including a magnetic material is illustrated. 2 (a-1) and 2 (b-1) are schematic horizontal cross-sectional views of the light blocking unit, and (a-2) and (b-2) are schematic vertical cross-sectional views.

The light blocking unit 110 includes a light absorber 200 therein. The light absorber 200 according to the present embodiment includes a magnetic material, and when the magnetic field is formed in the light blocking unit 110, the light absorber 200 is arranged according to the magnetic field. In the light blocking part 100 according to the present invention, the expression of the light blocking property (black mode) depends on whether the light absorber 200 is arranged according to the application of the magnetic field.

2 (a-1) and (a-2) show schematic structures of a state in which a magnetic field is not applied to the light blocking unit 110 (off state). When the light blocking unit 110 is in an off state, the light absorber 200 is irregularly dispersed in the light blocking unit 110. When the light absorber 200 is irregularly dispersed in the light blocking unit 110, light transmission is prevented (light blocking), and the light absorber 200 absorbs light, thereby implementing a black mode.

When the light blocking unit 110 is in an off state, when the image display unit 100 is also in an off state (not displaying an image), the transparent display device displays black.

In addition, when the light blocking unit 110 is in an off state, when the image display unit 100 is in an on state (a state of displaying an image), the transparent display device may be disposed only on the opposite side of the surface on which the light blocking unit 110 is disposed. The video can be recognized. Accordingly, the transparent display device of the present invention can be used as a double-side display device or a single-side display device depending on the application.

2B and 2B show schematic structures of a state in which a magnetic field is applied to the light blocking unit 110 (on state). When the light blocking unit 110 is turned on, the light absorber 200 is regularly arranged in the light blocking unit 110 according to the magnetic field. In the present invention, when the light absorbers 200 are regularly arranged in the light blocking unit 110, light is transmitted, thereby implementing a transparent mode.

When the light blocking unit 110 is in the on state, when the image display unit 100 is in an off state (not displaying an image), the transparent display device is in a transparent state.

In addition, when the light blocking unit 110 is in an on state, when the image display unit 100 is in an on state (a state of displaying an image), the transparent display device may visually recognize images from both sides of the image display unit 100. do.

The light absorber 200 of the present invention has an appropriate size and shape for transmitting light when arranged regularly. As such, the size of a material that allows transmission of light to depend on whether or not it is regularly arranged is known in the art.

The size of such a material is dependent on the wavelength of light used, for example, but may be a light absorber 200 having a size of 1 to 50,000 nm, but is not limited thereto.

In addition, in the present embodiment, the shape of the light absorber 200 is not particularly limited. For example, the structure may have a spherical shape, a polyhedron shape, a rugby ball shape, a bar shape, and the like, and in order to maximize the light blocking effect according to the on-off of the magnetic field, a rugby ball shape or a bar shape is preferable. In the case of having a rugby ball shape or a rod shape, it is preferable that the size in the major axis direction is 2 to 50,000 nm, and the size in the minor axis direction is 1 to 25,000 nm.

The light absorber 200 used in the present embodiment includes a magnetic material to be arranged in accordance with the application of a magnetic field. The magnetism of the magnetic body according to the present embodiment is not particularly limited as long as it can be arranged in accordance with the application of an electric field, and may have superparamagnetism, for example.

Superparamagnetism is a non-magnetic state when not exposed to a magnetic field, but has magnetic properties when exposed to a magnetic field. When the metal oxide magnetic material maintains ultrafine particles of 1 to 100 nm in size, the particles exhibit superparamagnetism. When a magnetic field is applied, it behaves as a micro magnet. The light absorbing agent 200 of the present embodiment including the magnetic material having such superparamagnetism can be controlled in its arrangement and position according to whether a magnetic field is applied to the light blocking unit 110.

In the present embodiment, the magnetic body can be used without particular limitation. For example, at least one oxide selected from the group consisting of Fe, Co, Ni, and FePt may be used, and iron oxide may be used in view of ease of manufacture and obtaining, and preferably maghemite Iron oxide or magnetite (Magnetite, Fe ₃ O ₄ ) of (γ-Fe ₂ O ₃ ) can be used.

In the present embodiment, the light absorber 200 may be a magnetic material alone, a magnetic material coated with an organic material or an inorganic material, or a mixture of the two. An example where the light absorber 200 is a coated magnetic body is schematically illustrated in FIG. 3.

Referring to FIG. 3, the light absorber 200 includes a magnetic body 220 and a coating material 210. The light absorber 200 may have a form (a) in which a single magnetic body 220 particle is wrapped with the coating material 210, and a shape in which a plurality of magnetic body 220 particles are wrapped with the coating material 210 (b). You can also have

The coating material 210 may be used without being particularly limited to organic materials or inorganic materials. For example, in the case of an organic material, a polymer may be used. In the case of an inorganic material, silica (SiO ₂ ), which may be easily coated on the magnetic body 220, may be used, but is not limited thereto.

The light shield 110 of this embodiment is provided with means capable of applying a magnetic field to arrange the light absorber if necessary. Referring to FIG. 2,

magnetic poles

115a and 115b for applying opposite magnetic properties are formed on one surface and the other surface of the light blocking unit 110, respectively. For example, if the first magnetic pole 115a is the S pole, the second magnetic pole 115b becomes the N pole.

In this embodiment, the

magnetic poles

115a and 115b become magnetic only when necessary, apply a magnetic field to the light shield 110, and arrange the light absorber 200 at a desired specific position. Thus, for example, an electromagnet system is a system that keeps magnetism only when necessary.

4 illustrates a schematic structure of a light blocking unit 110 that is turned on and off according to an application of an electric field as another embodiment of the present invention. 4 (a-1) and (b-1) are schematic horizontal cross-sectional views of the light blocking unit 110, and (a-2) and (b-2) are schematic vertical cross-sectional views.

The light absorbing agent 200 provided inside the light blocking unit 110 has one end fixed to an inner wall of the light blocking unit 100, has a bendable body, and is formed of a material capable of holding a charge. do. Since the light absorber 200 according to the present embodiment retains electric charge, the electric light is formed on both sides of the light blocking unit 110 when the electric field is not formed in the light blocking unit 110. If it is, it has a property to move toward the positive plate of the electric field. At this time, the light absorbing agent 200 according to the present embodiment has one end is fixed to the inner wall of the light blocking unit 110 and has a body that can be bent, the thickness of the light blocking unit 110 when an electric field is applied Will be arranged in the direction. Therefore, the expression of light blocking properties (black mode) depends on the arrangement according to the application of the electric field.

4 (a-1) and (a-2) show schematic structures of a state in which an electric field is not applied to the light blocking unit 110 (off state). When the light blocking unit 110 is in an off state, the light absorbing agent 200 is fixed to the inner wall of the light blocking unit 110, but one end thereof is irregularly positioned inside the light blocking unit 110 because it has a curved body. When the light absorber 200 is irregularly positioned inside the light blocking unit 110, light transmission is prevented (light blocking), and the light absorber 200 absorbs light, thereby implementing a black mode.

The operating state of the transparent display device when the light blocking unit 110 is in the off state is the same as the embodiment using the magnetic field.

4B and 4B show schematic structures of a state in which an electric field is applied to the light blocking unit 110 (on state). When the light blocking unit 110 is in an on state, the light absorbing agent 200 having a charge tries to move to one electrode plate, but one end thereof is fixed to the inner wall of the light blocking unit 110. It is arranged regularly in the thickness direction (the electric field formation direction). In the present invention, when the light absorber 200 is regularly arranged inside the light blocking unit 110, the light is transmitted, thereby implementing a transparent mode.

The operating state of the transparent display device when the light blocking unit 110 is in the on state is also the same as the embodiment using the magnetic field.

When the light absorbing agent 200 of the present invention is arranged regularly, the light absorbent 200 has an appropriate size and shape for transmitting light, which may be applied in the same manner as in the embodiment using the aforementioned magnetic field. However, in the present embodiment, since the light absorbing agent 200 has a curved body, it may be preferable to have a thin and long form such as a fiber form.

The light absorber 200 used in the present embodiment may be bent while retaining charge, and if such a material is not particularly limited, it may be used in the present invention.

If necessary, the transparent display device of the present invention having the above-described light blocking unit 110 may include a polarizing plate on one surface of the image display unit 100 in order to improve reflection viewing. For example, the light blocking unit 110 may be provided on an opposite side of the surface of the image display unit 100.

As described above, the transparent display device of the present invention can implement a black mode by blocking light transmitted through the light blocking unit having a magnetic material very simply. In addition, the display device may be used as a transparent display device for viewing information on both sides and a single-side display device for viewing information on only one surface. In addition, when the polarizing plate is provided, an improved reflection time can be exhibited.

As described above, although preferred embodiments have been presented to aid in understanding the present invention, these examples are merely illustrative of the present invention and are not intended to limit the appended claims, but are within the scope and spirit of the present invention. It is apparent to those skilled in the art that various changes and modifications to the embodiments are possible, and such variations and modifications are within the scope of the appended claims.

[Description of the code]

100: image display unit 110: light blocking unit

115a, 115b: Stimulus 200: Absorbent

210: light absorber coating material 220: magnetic material

Claims

An image display unit having a transparent OLED; And

A light blocking unit bonded to at least one surface of the image display unit and provided with a light absorbing agent whose arrangement is changed according to an electric field or a magnetic field, and being turned on or off by application of an electric field or a magnetic field;

Transparent display device comprising a.
The transparent display device of claim 1, wherein the light blocking unit includes a light absorbing agent including a magnetic material and is turned on and off according to an application of a magnetic field.
The transparent display device of claim 2, wherein the light blocking unit is turned on and off using an electromagnet system.
The transparent display device of claim 2, wherein the light absorber is at least one of a magnetic material alone and a magnetic material coated with an organic material or an inorganic material.
The transparent display device of claim 2, wherein the magnetic material has a superparamagnetism.
The transparent display device of claim 2, 4 or 5, wherein the magnetic material includes at least one oxide selected from the group consisting of Fe, Co, Ni, and FePt.
The transparent display device of claim 2, 4 or 5, wherein the magnetic material has a size of 1 to 100 nm.
The transparent display device of claim 1, wherein one end of the light blocking unit is fixed to an inner wall of the light blocking unit and has a body that can be bent, and has a light absorber capable of holding electric charges, thereby being turned on and off by application of an electric field. .
The transparent display device of claim 8, wherein the light blocking unit applies an electric field by generating a potential difference on both surfaces of the light blocking unit.
The transparent display device of claim 8, wherein the light absorber is arranged in the thickness direction of the light blocking unit when an electric field is applied.
The transparent display device of claim 2, wherein the light blocking unit is disposed at at least one of a front surface and a rear surface of the image display unit.
The transparent display device of claim 2 or 8, wherein when the image display unit and the light blocking unit are turned on, external light is transmitted through the light blocking unit, and an image is displayed on the front and rear surfaces of the image display unit.
The transparent display device of claim 2 or 8, wherein when the image display unit and the light blocking unit are in an off state, external light is blocked through the light blocking unit and black is displayed as the image display unit does not display an image.
The transparent display device of claim 2 or 8, wherein when the image display unit is on and the light blocking unit is off, external light is blocked through the light blocking unit, and an image is displayed on the front or the rear of the image display unit.
The transparent display device of claim 2, wherein a polarizing plate is provided on a surface opposite to the light blocking unit of the image display unit.