CN100438066C - Double-sided display device - Google Patents

Abstract

A double-sided display device includes a substrate, a first light-emitting element, a second light-emitting element and an upper cover. Both light-emitting elements are arranged on the substrate, wherein the first light-emitting element has a first light-emitting direction, and the second light-emitting element is adjacent to the first light-emitting element and has a second light-emitting direction. The upper cover is located above the first light-emitting element and the second light-emitting element, and maintains a spacing of 1 to 100 microns between the upper cover and the light-emitting elements.

Description

Double-sided display device

technical field

The invention relates to a double-sided display device, in particular to a double-sided organic electroluminescence display device which can prevent light-emitting elements from being damaged by external forces.

Background technique

The forms of electronic products are becoming more and more diversified, and the double-sided display function has become the main feature of the new generation of electronic products. For example, the double-sided display device inside the mobile phone can display the main function window of the mobile phone on one side, and display the time on the other side. Currently, double-sided display devices produced in the industry are usually formed by bonding two single-sided display panels, such as a liquid crystal display panel and an organic electroluminescent panel, or two organic electroluminescent panels.

FIG. 1 shows a conventional double-sided display device. The existing double-sided display device 10 is formed by laminating a first display panel 11 and a second display panel 12 . The first display panel 11 has a transparent substrate 111 , a first electrode 112 , a light emitting layer 113 , a second electrode 114 and a packaging cover 115 . The first electrode 112 is formed on the transparent substrate 111 . The light emitting layer 113 is located between the first electrode 112 and the second electrode 114 . The edge of the packaging cover 115 is attached to the transparent substrate 111 and covers the second electrode 114 .

The second display panel 12 also has a transparent substrate 121 , a third electrode 122 , a light emitting layer 123 , a fourth electrode 124 and a packaging cover 125 . The third electrode 122 is formed on the transparent substrate 121 . The light emitting layer 123 is located between the third electrode 122 and the fourth electrode 124 . The edge of the packaging cover 125 is attached to the transparent substrate 121 and covers the fourth electrode 124 . The packaging cover 115 of the first display panel 11 is attached to the packaging cover 125 of the second display panel 12 to form a double-sided display device 10 .

As mentioned above, the existing double-sided display device 10 has two packaging covers 115 and 125 and two transparent substrates 111 and 121 . Therefore, the entire device has a larger volume, a thicker thickness, and a heavier weight, which does not conform to the trend of light, thin, short, and small electronic products. In order to reduce the thickness, it is necessary to reduce the distance between the package cover and the transparent substrate, but in this way, the package cover is easy to be bent due to external pressure, or the particles generated in the pressing panel process will cause damage to the components on the transparent substrate.

In addition, the two display panels 11 and 12 are manufactured through different processes, so the manufacturing process is complicated and time-consuming. Moreover, the two display panels 11 and 12 must be driven separately, which cannot save materials such as chips and flexible circuit boards, and increases the cost.

The existing double-sided display device is relatively thick and the process is complex, and the process needs to use more materials such as integrated circuits (ICs) and flexible printed circuit boards (FPCs). Particles generated during the process can easily damage components on the transparent substrate. The present invention provides a double-sided display device to solve the above disadvantages.

Contents of the invention

The purpose of the present invention is to provide a double-sided display device, which has a thinner thickness and is suitable for a simpler process; in terms of structural design, it can prevent the particles generated in the process from damaging the light-emitting elements on the substrate.

The double-sided display device of the present invention includes a substrate, a first light-emitting element, a second light-emitting element and a top cover. Two kinds of light-emitting elements are arranged on the substrate, wherein the first light-emitting element has a first light-emitting direction, and the second light-emitting element is adjacent to the first light-emitting element and has a second light-emitting direction. The upper cover is located above the first light-emitting element and the second light-emitting element, and keeps a distance of 1 to 100 microns from the light-emitting elements.

The distance between the upper cover and the light-emitting elements is adjusted according to the size of the particles that may be generated in the general process. In a preferred embodiment, the first light-emitting element may emit light upwards, and the second light-emitting element may emit light downwards, and there is a spacer layer between the two light-emitting elements. A supporting layer is provided between the upper cover and the spacer layer or the non-upward light-emitting area such as the second light-emitting element, so that the upper cover can be prevented from being deformed by pressure and further damaging the components on the substrate.

Description of drawings

Fig. 1 is an existing double-sided display device;

Fig. 2 is the first embodiment of the double-sided display device of the present invention;

FIG. 3A is a first planar configuration diagram of a light-emitting element according to a second embodiment of the present invention;

FIG. 3B is a second planar configuration diagram of light-emitting elements according to the second embodiment of the present invention;

FIG. 4 is a second embodiment of the double-sided display device of the present invention; and

FIG. 5 is a third embodiment of the double-sided display device of the present invention.

simple notation

10 double-sided display device (existing) 221 opaque electrodes

11 The first display panel 222 Organic light-emitting layer

111 transparent substrate 223 transparent electrode

112 first electrode 23 downward light-emitting element

113 light-emitting layer 231 light-transmitting electrode

114 second electrode 232 organic light-emitting layer

115 package cover 233 opaque electrode

12 second display panel 24 top cover

121 transparent substrate 25 drive components

122 third electrode 25a driving element

123 light-emitting layer 25b driving element

124 fourth electrode 26 adhesive

125 package cover 30 double-sided display device

20 double-sided display device 31 compartment layer

21 substrate 32 support layer

22 upward light-emitting elements 40 double-sided display device

42 flat

Detailed ways

The double-sided display device of the present invention is described in detail in conjunction with the icons, and the preferred embodiments are listed as follows:

Please refer to FIG. 2 , which is the first embodiment of the present invention. The double-sided display device 20 includes a substrate 21 , two light emitting elements 22 and 23 for emitting light in different directions, and a top cover 24 . In the following description, both the substrate 21 and the upper cover 24 are not limited to organic materials or inorganic materials, which are described first.

As shown in the figure, the light emitting elements 22 and 23 are adjacent to each other and disposed on the same substrate 21 . The substrate 21 may be selected from glass or plastic material substrates. In this embodiment, the light emitting element 22 emits light upward, and the light emitting element 23 emits light downward so that both the front and back sides of the display device 20 can be used to display images. The upper cover 24 is located above the light-emitting elements 22 and 23 to protect them from external damage, and a hard material with a light transmittance of more than 30%, such as glass or hard plastic, should be selected. An adhesive 26 is used to bond the upper cover 24 and the substrate 21 . It should be emphasized that the distance H between the upper cover 24 and the light-emitting elements 22 and 23 is maintained at 1 to 100 micrometers to prevent the particles generated in the process from crushing the light-emitting elements 22 and 23 .

The upward light-emitting element 22 can be a top-emission organic light-emitting diode, and an opaque electrode 221 is fabricated on the substrate 21, and then an organic light-emitting layer 222 is formed on the opaque electrode 221, and a light-transmitting electrode 223 is formed on the on the organic light emitting layer 222 . The downward emitting element 23 can be a bottom emitting organic light emitting diode, and its structure also includes a transparent electrode 231 , an organic light emitting layer 232 and an opaque electrode 233 . Different from the top emission OLED, the electrode formed on the substrate 21 is a light-transmitting electrode.

The organic light emitting diode as the upward emitting element 22 or the downward emitting element 23 can be a polymer organic light emitting diode (PLED) or a small molecule organic light emitting diode. The opaque electrodes 221 and 233 can be a reflective electrode or a black electrode, and their materials can be selected from metals, semiconductors, metal oxides, or conductive polymers. The transparent electrodes 223 and 231 are usually made of indium tin oxide and indium zinc oxide. The material of the organic light-emitting layers 222 and 232 can be fluorescent or phosphorous optically active and relatively strong luminescent compounds.

Neither the light-transmitting electrode nor the light-transmitting electrode is limited to be an anode or a cathode, and the region between the electrode and the light-emitting layer is a hole or electron transfer. In the hole transfer region, a hole injection layer (not shown) or a hole transport layer (not shown) can be selectively inserted. In the electron transfer region, an electron hole injection layer (not shown) or an electron transport layer (not shown) can be selectively inserted.

The electron transport layer can be made of 8-hydroxyquinoline aluminum (Alq), tripolybenzimidazole (TPBI), anthracene derivatives, fluorine derivatives (fluorine, spirofluorine) and other materials, and then doped with alkali metal halides , alkaline earth metal halides, alkali metal oxides or metal carbonates and other n-type dopants to enhance their electron mobility.

The material of the electron injection layer can be a metal compound, and an alkali metal halide, an alkaline earth metal halide, an alkali metal oxide or a metal carbonate compound or an organic compound containing the above-mentioned n-type dopant with a good degree of coordination with the work function of the opaque electrode is used. layer.

The hole transport layer material can be allylamine compounds such as NPB (N,N-di(naphthalene-1-yl)-N,N-diphenyl-benzidene). The material of the hole injection layer can be allylamine or CuPc and other cyanine compounds.

Please refer to FIG. 3A , which is a first plane configuration diagram of a light emitting element according to a first embodiment of the present invention. A plurality of upward light-emitting elements 22 and a plurality of downward light-emitting elements 23 are arranged on the substrate 21 in a chessboard pattern alternately, of course, they can also be arranged on the substrate 21 in strips. The upward light-emitting element 22 and the downward light-emitting element 23 can be electrically connected to the same driving element 25 to display the same picture on the front and back of the display device 20 .

Please refer to FIG. 3B , which is a second plane configuration diagram of light emitting elements according to the first embodiment of the present invention. The upward light-emitting element 22 is electrically connected to the driving element 25a, and the downward light-emitting element 23 is electrically connected to the driving element 25b, so as to independently control the image on the front and back of the display device 20 . The driving elements 25, 25a and 25b can be selected from various types of thin film transistors. Incidentally, the plane configurations shown in FIGS. 3A-3B can also be applied to the following embodiments.

Please refer to FIG. 4 , which is a second embodiment of the present invention. In the present invention, a supporting layer is grown in the non-upward light-emitting area of the double-sided display device to isolate the substrate and the glass back cover, and prevent the back cover from crushing the components on the substrate. In the double-sided display device 30 , there is a spacer layer 31 between the upward light-emitting element 22 and the downward light-emitting element 23 . A supporting layer 32 is grown on the spacer layer 31 to prevent the upper cover 24 from sinking due to external force. In order to maintain an effective distance between the upper cover 32 and the light-emitting elements 22 and 23 , the support layer 32 should have a height of at least 1 to 100 microns, but is not limited to using organic materials or inorganic materials to make the support layer 32 .

In the above two embodiments, the upper cover 24 has a body with an inner side concave upward, and the lower edge of the side wall of the upper cover 24 is sealed with the substrate 21 by an adhesive 26 . However, the upper cover 24 can also be replaced by a flat plate, such as the third embodiment of the present invention shown in FIG. 5 .

Please refer to FIG. 5 , the double-sided display device 40 covers the light-emitting elements 22 and 23 with a flat plate 42. The distance between the lower surface of the flat plate 42 and the light-emitting elements 22 and 23 is maintained by the thickness of the adhesive 26. The composition of the encapsulant, determined by volume. The supporting strength of the adhesive 26 may be insufficient, so a supporting layer 32 as shown in FIG. 4 may be used for reinforcement.

The above embodiments are all described with an active display, but the features of the present invention can also be applied to a passive display. When the present invention is compared with the prior art, it has the following characteristics and advantages:

1. Can save integrated circuit (IC) or flexible circuit board (FPC) and other materials to reduce costs.

2. Seal the light-emitting element with a back cover with a visible light transmittance greater than 30% to prevent moisture from entering the light-emitting area of the panel.

3. A supporting layer is grown in the non-upward light-emitting area of the double-sided display device to isolate the substrate and the back cover, and prevent the back cover from crushing the components on the substrate.

The above detailed descriptions are specific descriptions of the preferred embodiments of the present invention, but the above embodiments are not intended to limit the patent scope of the present invention, and all equivalent implementations or changes that do not depart from the spirit of the present invention should be included in the scope of the present invention. within the scope of the patent.

Claims (19)

1. double-side display device comprises:

Substrate;

First light-emitting component is arranged on this substrate, and has first light emission direction;

Second light-emitting component is arranged on this substrate, and adjacent to this first light-emitting component, this second light-emitting component has second light emission direction; And

Loam cake is positioned at this first light-emitting component and this second light-emitting component top, and and these light-emitting components between keep 1 to 100 micron spacing;

Wherein, also comprise wall between this first light-emitting component and this second light-emitting component.

2. double-side display device as claimed in claim 1 comprises the staggered or bar row shape configuration with the chess checkerboard type of a plurality of these first light-emitting components and a plurality of this second light-emitting component.

3. double-side display device as claimed in claim 1, wherein this first light-emitting component comprises:

Light tight electrode is formed on this substrate;

Organic luminous layer is formed on this light tight electrode; And

Euphotic electrode is formed on this organic luminous layer.

4. double-side display device as claimed in claim 1, wherein this second light-emitting component comprises:

Euphotic electrode is formed on this substrate;

Organic luminous layer is formed on this euphotic electrode; And

Light tight electrode is formed on this organic luminous layer.

5. double-side display device as claimed in claim 1, wherein this first light-emitting component is the macromolecule Organic Light Emitting Diode.

6. double-side display device as claimed in claim 1, wherein this second light-emitting component is the macromolecule Organic Light Emitting Diode.

7. double-side display device as claimed in claim 1, wherein the material of this loam cake is the material of light transmittance more than 30%.

8. double-side display device as claimed in claim 1, the wherein edge of this loam cake and this base plate bonding.

9. double-side display device as claimed in claim 1, wherein this first light-emitting component and this second light-emitting component are connected to same driving element.

10. double-side display device as claimed in claim 1, wherein this first light-emitting component and this second light-emitting component are connected to the different driving element.

11. a double-side display device comprises:

Substrate;

First light-emitting component is arranged on this substrate, and this first light-emitting component is for upwards luminous;

Second light-emitting component is arranged on this substrate, and adjacent to this first light-emitting component, this second light-emitting component is for luminous downwards;

Loam cake is positioned at this first light-emitting component and this second light-emitting component top; And

Supporting layer is supported between this loam cake and these light-emitting components so that this loam cake and these light-emitting components keep spacing;

Wherein also comprise wall between this first light-emitting component and this second light-emitting component, this supporting layer is formed on this wall.

12. double-side display device as claimed in claim 11, wherein this supporting layer has 1 to 100 micron height.

13. double-side display device as claimed in claim 11 comprises the staggered or strip columnwise configuration with the chess checkerboard type of a plurality of these first light-emitting components and a plurality of this second light-emitting component.

14. double-side display device as claimed in claim 11, wherein this first light-emitting component comprises:

Light tight electrode is formed on this substrate;

Organic luminous layer is formed on this light tight electrode; And

Euphotic electrode is formed on this organic luminous layer.

15. double-side display device as claimed in claim 11, wherein this second light-emitting component comprises:

Euphotic electrode is formed on this substrate;

Organic luminous layer is formed on this euphotic electrode; And

Light tight electrode is formed on this organic luminous layer.

16. double-side display device as claimed in claim 11, wherein this first light-emitting component is the macromolecule Organic Light Emitting Diode.

17. double-side display device as claimed in claim 11, wherein this second light-emitting component is the macromolecule Organic Light Emitting Diode.

18. double-side display device as claimed in claim 11, wherein the material of this loam cake is the material of light transmittance more than 30%.

19. double-side display device as claimed in claim 11, the wherein edge of this loam cake and this base plate bonding.

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