JP2002006765A - Display device and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfy the request for the miniaturization and the weight saving of a liquid crystal display element by using an organic EL element, and to form a direct lighting system for display element. SOLUTION: The display device is provided with a nonluminous display element and an organic electroluminescence element which lights the display element directly from the observation surface side about the display element. The mentioned organic EL element may be disposed out of the display area of the mentioned display element when viewed from the observation surface side. It is suitable that the organic EL element is disposed on the rear side surface of a supporting member disposed at the observation surface side of the display element. It is preferable that the supporting member covers the whole display area of the display element when viewed from the observation side. Besides, it is suitable that the organic EL element have a shape suitable for illuminating the whole display element uniformly. The display element may be a reflection type liquid crystal display element including a liquid crystal showing a cholesteric phase at room temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a display device and a method for manufacturing the same.

[0002]

BACKGROUND OF THE INVENTION Today, liquid crystal display devices are used in various devices as means for displaying images and character data. As a typical example of such devices, for example, PD
A (Personal Digital Assist)
ant).

[0003] It is generally required that the liquid crystal display element as described above be reduced in size and weight, and be designed in various shapes. With the goal of responding to this request,
Organic electroluminescence (Electro)
A technology using a Luminescence element has been proposed.

Japanese Patent Application Laid-Open No. H11-307241 discloses an "organic electroluminescence" light source device using an organic electroluminescence structure as a light source.
FIG. 8 is a schematic sectional view showing the configuration of the light source device described in the above publication. The light source device 101 includes an organic electroluminescent structure 102a, a reflector 102b provided as needed, and a light transmitting body 103.
Light emitted from the organic electroluminescence structure 102a is condensed by the light transmitting body 103 formed in a lens shape, and is efficiently injected into the light guide diffusion plate 104, and the light is diffused by the light diffusion function of the light guide diffusion plate 104. The light is emitted in the form of a plane to serve as a backlight of the liquid crystal display device 105.

On the other hand, in the case of a reflection type liquid crystal display device, a front light for illuminating from an observation surface side of the display device is provided instead of a backlight for the purpose of improving visibility in a dark place or the like. For example, in the case of a reflective liquid crystal display element which performs display using selective reflection of a cholesteric phase, the light utilization efficiency is usually 50% or less, so that as much light as possible is guided to the display element and scattering occurs. It is required that the optical member that reduces the contrast be reduced on the observation surface as much as possible.

According to the present invention, the display element is reduced in size and weight and can be designed into various shapes by appropriately utilizing the electroluminescence element.
It is an object of the present invention to satisfy this requirement and to form direct illumination on the display surface of the display element.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object. A display device according to the present invention includes a non-light-emitting display element and an electroluminescence element that directly illuminates the display element from the observation surface side with respect to the display element.

[0008] The electroluminescent element may be arranged outside a display area of the display element when viewed from an observation surface side. The display element may be arranged outside the display area of the display element as viewed from the observation surface side, and may be arranged along the display area. The display device may be arranged outside the display area of the display element as viewed from the observation surface side, and may be arranged so as to surround the display area.

It is preferable that the electroluminescent element is arranged on a back surface of a support member arranged on the observation surface side of the display element. It is preferable that the support member covers the entire display area of the display element when viewed from the observation side.

[0010] The electroluminescent element may be arranged on the back surface of a plate-shaped position input device arranged on the observation surface side of the display element.

It is preferable that the electroluminescent element has a shape suitable for uniformly illuminating the entire display element. The electroluminescent element may have a shape suitable for converging a predetermined portion of the display element relatively more than other portions.

In the above-described electroluminescent element, the whole shape may be formed by using one or a plurality of unit-shaped electroluminescent elements.

The display element may be a reflection type liquid crystal display element, or may be a reflection type liquid crystal display element which performs display using selective reflection of a cholesteric phase.

[0014]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

First Embodiment FIG. 1 is a schematic diagram of a display device 2 according to a first embodiment of the present invention.
(1) is a plan view, (2) is a side cross-sectional view, and (3) is an enlarged side cross-sectional view of an end portion 6 including an organic electroluminescence (hereinafter, referred to as organic EL) light source unit 4. The display device 2 includes a protective cover 10 provided with an organic EL light source unit 4 at an edge of a surface, and a display element 8.

The display element 8 is fixed to, for example, a portable information device (not shown), and displays characters and images under the control of a control unit (not shown) of the portable information device. As the display element 8, various non-light-emitting elements can be used. For example, a reflective liquid crystal display element is preferable. The protective cover 10 is a plate-shaped member that covers the viewing side of the display element 8, and is fixed to the portable information device (not shown) or the like, like the display element 8. The protective cover 10 is formed, for example, from a transparent member such as glass or acrylic resin. On one flat surface of the protective cover 10, the organic EL light source unit 4 having a constant width is formed at an edge portion (FIGS. 1A and 1B). The surface on which the organic EL light source unit 4 is formed is disposed so as to face the display element 8 (FIG. 1 (2)).

FIGS. 2A and 2B show the organic EL light source section 4.
FIG. 2 is a cross-sectional view illustrating an example of the configuration of a protective cover 10. First, in FIG. 2A, the organic EL light source unit 4 is
2. It comprises an electrode layer 14, an organic light emitting layer 16, an electrode layer 18, and a protective layer 20 made of a transparent material. As a material of the substrate 12, besides a glass substrate, a flexible substrate such as polycarbonate, polyethersulfone (PES), or polyethylene terephthalate can be used. The materials and configurations of the electrode layers 14 and 18 and the organic light emitting layer 16 are not particularly limited, and various conventionally known materials and configurations can be employed. Note that at least the electrode layer 18 needs to be formed of a light-transmitting material so that light emission from the organic light-emitting layer 16 can be extracted. Therefore, it is preferable that the electrode layer 18 be an anode and the electrode layer 14 be a cathode. . Further, a charge injection layer or a charge transport layer may be provided between the organic light emitting layer 16 and the electrode layers 14 and 18 as needed.

The above layers are laminated by utilizing conventional techniques. That is, the electrode layer 14, the organic light emitting layer 16, the electrode layer 18, and the protective layer 20 are sequentially stacked on the substrate 12 by using the conventional technology.

For example, a single-plate organic EL light source sheet 22 shown in FIG. 7A is formed. Figure 7 (1)
2 (1) by appropriately cutting and combining the cut units and pasting them to the protective cover 10.
The configuration of the organic EL light source unit 4 and the protective cover 10 as described above can be formed.

The structure is such that a potential difference can be formed between the electrode layers 14 and 18 by an external power supply 24. When a potential difference between the electrode layer 14 and the electrode layer 18 is applied, the organic light emitting layer 16 emits light.

As shown in FIG. 2B, the organic EL light source section 4 is formed on the protective cover 10 by using a conventional technique on an electrode layer 14, an organic light emitting layer 16, an electrode layer 18, and a protective layer. 20 may be formed by directly forming by vapor deposition or coating.

Returning to FIG. When the organic light emitting layer 16 emits light, the band-shaped organic EL light source unit 4 emits light. Due to the light emission, the display element 8 surrounded by the edge of the protective cover 10 when viewed from the observation side receives illumination from the edge on the observation side. Therefore, the observer can observe the display element 8 illuminated through the transparent protective cover 10.

Since the display element is directly irradiated from the organic EL light source section 4, it is not necessary for the protective cover 10 to have a function of guiding the light emitted from the organic EL light source section 4. Therefore, a protective cover having a sufficiently high light transmittance can be used, and a bright display can be realized.

Second Embodiment FIG. 3 is a schematic diagram of a display device 2 according to a second embodiment of the present invention.
(1) is a plan view, and (2) is a side sectional view. The display device 2 according to the second embodiment has the following configuration except for the points described below.
The display device 2 according to the first embodiment shown in FIG.
It is similar.

That is, in the second embodiment, the substrate 1
The organic EL light source unit 4 including the light emitting element 2 is formed as a separate member from the protective cover 10. After both are formed as separate members, the organic EL light source unit 4 is bonded and supported by a suitable support member.

In this embodiment, the protective cover 10 and the organic E
Since there is no need to directly join the L light source unit 4, the manufacturing of the display device is facilitated.

Third Embodiment FIG. 4 is a schematic diagram of a display device 2 according to a third embodiment of the present invention.
(1) is a plan view, and (2) is a side sectional view. The display device 2 according to the third embodiment has the following configuration except for the points described below.
The display device 2 according to the first embodiment shown in FIG.
It is similar.

That is, in the third embodiment, the organic E
The substrate 12 of the L light source unit 4 forms a part of the touch panel. Specifically, the substrate 12 is a plate-shaped substrate having a size to cover the display element 8, and as shown in FIG.
The substrate 12 of the light source unit 4, the film 26 located on the outer surface of the display device 2 and having substantially the same size as the substrate 12, and the sealing material 28 constitute a touch panel unit. The type of the touch panel employed in this embodiment is not particularly limited, and may be an analog type touch panel or a matrix type touch panel.

Since some of the members of the organic EL light source unit 4 and some of the members of the touch panel are used, the number of components is reduced, and the display is light and small, and has a bright and high-quality display with little optical loss. It can be an element.

Fourth Embodiment FIG. 5 is a schematic diagram of a display device 2 according to a fourth embodiment of the present invention.
(1) is a plan view, and (2) is a side sectional view. The display device 2 of the fourth embodiment is substantially similar to the display device 2 of the first embodiment shown in FIG. However, the following differences exist.

In the present embodiment (fourth embodiment), the shape of the organic EL light source section 4 in a side cross section is different from that of the first embodiment. That is, in the first embodiment, both the protective cover 10 and the organic EL light source unit 4 are flat and arranged in parallel with the plane of the display element 8. Form)
A concave shape is provided in the side section so that light emitted from the organic EL light source unit 4 is focused on the display element 8 (see FIGS. 5 (2) and 6 (1)). FIG. 5B is a diagram illustrating a cross section taken along a plane AA in FIG. The cross section along the plane BB in FIG. 5A may have a concave shape like the organic EL light source unit 4 in FIG. 5A.

Here, the plane AA is parallel to the side a of the display area and perpendicular to the side b.
Is a plane that cuts through. The plane BB is a plane that cuts the protective cover 10 and the display element 8 parallel to the side b of the display area and perpendicular to the side a. FIG. 6 is an enlarged sectional side view of the end 6 of the display device 2 including the organic EL light source unit 4.

In the creation of the display device 2 shown in FIG.
The end of the protective cover 10 made of a transparent member such as glass or acrylic resin is formed in a concave shape as shown in FIG. 6A, and the organic EL is fitted along the shape.
The light source unit 4 may be deformed, and the organic EL light source unit 4 may be attached to the deformed end of the protective cover 10.

As shown in FIG. 6A, the organic EL light source section 4 has an appropriate concave shape so as to optimize the brightness of the entire display element 8 and to make a specific portion of the display element 8 particularly bright. (Or especially darker).

In addition to the fourth embodiment shown in FIG. 6A, the shape of the side cross section of the organic EL light source unit 4 can be variously set. For example, the slope shape in FIG. 6 (2), the convex shape in FIG. 6 (3), the staircase shape in FIG. 6 (4), all of which are shown in FIG.
Organic E in plane AA (or plane BB) in (1)
It can be set as the cross-sectional shape of the L light source unit 4.

The sectional shape of the organic EL light source section 4 on the plane AA (or plane BB) is shown in FIG.
It is also possible to set a combination of a concave shape, (2) a slope shape, (3) a convex shape, or (4) a step shape.

{Fifth Embodiment} FIG. 7 shows a fifth embodiment of the present invention.
It is the schematic of the formation unit of the organic EL light source part 4 which concerns on the manufacturing method of the display element which is embodiment.

As shown in the description of FIG. 2A, the single-plate-shaped organic EL light source sheet 22 includes the substrate 12 and the electrode layer 1.
4, the organic light emitting layer 16, the electrode layer 18, and the protective layer 20
It is formed by laminating using a conventional technique.
As shown in FIG. 7A, the L-shaped organic E
The light source unit 4 is appropriately divided into the formation units 30. The organic EL light source unit 4 shown in FIG. 7B can be formed by combining the divided forming units 30.

By forming the organic EL light source sheet 22 and forming the organic EL light source unit forming unit 30 therefrom, the raw materials used in forming the organic EL light source unit 4 can be effectively utilized.

The shape of the forming unit 30 formed from the organic EL light source sheet 22 is not limited to the above-described L-shape, and may be, for example, a strip shape.

Although the specific embodiments of the present invention have been described above, the present invention is not limited to these embodiments and can be variously modified. In particular, various non-light-emitting display elements can be used as the display element 8, for example, a reflective liquid crystal display element,
A reflective liquid crystal display element including a liquid crystal exhibiting a cholesteric phase at room temperature can be used.

In the case of a reflection type liquid crystal display element which performs display using selective reflection of a cholesteric phase, the light utilization efficiency is usually 50% or less, so that as much light as possible is guided to the display element and scattering is reduced. It is required to minimize the arrangement of optical members that generate and lower the contrast on the observation surface. Since the display device of each of the above embodiments uses the direct illumination system using the organic electroluminescence element, it is possible to irradiate the display element with more light, and since it is not necessary to provide a light guide plate on the observation surface, This is extremely effective for achieving both bright display and prevention of contrast reduction.

In each of the above embodiments, an example in which an organic EL element is used as a light source has been described. Organic E
The L element is particularly preferable from the viewpoints of low voltage driving, ease of manufacturing, and the like, but an inorganic EL element can also be used.

[0044]

According to the present invention, in a display device using a non-light emitting display element such as a reflection type liquid crystal display element, it is possible to make the light source section and the entire display section thinner and smaller. . Therefore, various shapes can be realized in the design of the entire display device.

Since a light guide plate is not required, a bright, high-contrast, high-quality display can be realized.

By arranging the electroluminescent element outside the display area, visibility is not impaired.

The substrate of the organic EL light source section can also be used as the substrate of a plate-like position input device such as a touch panel.

The shape of the organic EL light source section can be optimized for various purposes. For example, the size of the outer frame of the display device can be reduced, and the degree of concentration or dispersion of light on the display element can be changed.

Further, according to the display device manufacturing method of the present invention, since the entire shape of the light source is obtained by using the unit-shaped element, the material can be effectively used.

[Brief description of the drawings]

FIG. 1 shows a display device according to a first embodiment of the present invention.
(1) Plan view, (2) Side sectional view, (3) Enlarged side sectional view of an end including an organic EL light source unit.

FIG. 2 is a cross-sectional view illustrating an example of a configuration of an organic EL light source unit and a protective cover in the display device according to the first embodiment of the present invention.

FIG. 3 shows a display device according to a second embodiment of the present invention;
It is (1) a top view, (2) sectional side view.

FIG. 4 shows a display device according to a third embodiment of the present invention;
It is (1) a top view, (2) sectional side view.

FIG. 5 shows a display device according to a fourth embodiment of the present invention.
It is (1) a top view, (2) sectional side view.

FIG. 6 is an enlarged side sectional view of an end including an organic EL light source unit in a display device according to a fourth embodiment of the present invention.

FIG. 7 is a schematic diagram of a unit for forming an organic EL light source unit in a method of manufacturing a display element according to a fifth embodiment of the present invention.

FIG. 8 is a schematic sectional view showing a configuration of a conventional light source device.

[Explanation of symbols]

2: display device, 4: organic EL light source portion, 6: display device end portion, 8: display element, 10: protective cover, 12: substrate, 1
4: electrode layer, 16: organic light emitting layer, 18: electrode layer, 20:
Protective layer, 22: organic EL light source sheet, 24: external power supply,
26: film, 28: sealing material, 30: organic EL light source unit forming unit.

Continuation of the front page F term (reference) 2H091 FA23Z FA26Z FA44Z LA30 5B087 AA06 CC01 5G435 AA18 BB12 BB16 DD13 EE27 GG26 LL07

Claims (13)

[Claims] 1. A display device comprising: a non-light-emitting display element; and an electroluminescence element for directly illuminating the display element from an observation surface side with respect to the display element. 2. The electroluminescent element according to claim 1,
The display device according to claim 1, wherein the display device is disposed outside a display area of the display element when viewed from an observation surface side. 3. The electroluminescent element according to claim 1,
The display device according to claim 1, wherein the display device is disposed outside a display area of the display element when viewed from an observation surface side, and is disposed along the display area. 4. The electroluminescent device according to claim 1,
The display device according to claim 1, wherein the display device is disposed outside a display area of the display element when viewed from an observation surface side, and is disposed so as to surround the display area. 5. The electroluminescent device according to claim 1,
The display device according to claim 1, wherein the display device is disposed on a back surface of a support member disposed on an observation surface side of the display element. 6. The display device according to claim 5, wherein the support member covers the entire display area of the display element when viewed from an observation side. 7. The electroluminescent element according to claim 1,
The display device according to claim 1, wherein the display device is disposed on a back surface of a plate-shaped position input device disposed on an observation surface side of the display element. 8. The electroluminescent device according to claim 1,
The display device according to claim 1, wherein the display device has a shape suitable for uniformly illuminating the entire display element. 9. The electroluminescent element according to claim 1,
For a predetermined portion of the display element, a shape suitable for condensing relatively more light than other portions is provided.
The display device according to claim 1. 10. The display according to claim 1, wherein the whole shape is formed by using one or a plurality of unit-shaped electroluminescent elements in the electroluminescent element. apparatus. 11. The display device according to claim 1, wherein the display element is a reflective liquid crystal display element. 12. The display device according to claim 1, wherein the display element is a reflective liquid crystal display element that performs display using selective reflection of a cholesteric phase. 13. A step of forming an entire shape of a light source by using one or a plurality of unit-shaped electroluminescent elements, and disposing the light source of the entire shape on the observation surface side of a non-light emitting display element. And a manufacturing method of the display device.