JP2002023654A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device using an EL display having good appearance and high luminance of a displayed image even when the device is used for a display panel of an audio appliance which emphasizes factors relating to the design. SOLUTION: In the display device 1, an image is displayed on the display screen 5a of the EL display 5 and the light of the image emitted from the display screen 5a and transmitted through a front circularly polarizing plate 13 and a protective panel 9 disposed in the front of the El display 5 is observed. In this device, the surface 13a of the circularly polarizing plate 13 is adhered with a transparent adhesive 11 to the back face of the protective panel 9 opposing the display screen 5a of the EL display 5, and an AR film 15 is adhered with the transparent adhesive 11 to the back face 13b of the circularly polarizing plate 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a display device in which an EL display using an EL (electroluminescence) element is covered with a light-transmitting protective panel.

[0002]

2. Description of the Related Art In recent years, an EL display using a thin film EL element represented by an organic EL is expected to be a self-luminous low-voltage driven thin display which does not require a backlight unlike a liquid crystal display. Specifically, application to a display panel or the like of a car audio device is being studied.

[0003] In the case of organic EL, this EL display is constructed by sandwiching a light emitting layer of zinc sulfide (ZnS) or manganese (Mn) between an electrode layer (the electrode layer on the display surface side is a transparent electrode: ITO) and a glass substrate. However, since the light emitted by the light emitting layer has polarized light, a circularly polarizing plate that corrects the polarized light and improves the contrast ratio of the displayed image is adhered to the glass substrate on the display surface side.

In front of the EL display, PMMA (polymethyl methacrylate) or PC having high transparency is used to protect the circularly polarizing plate and the EL display itself.
A protection panel made of (polycarbonate) is provided.

[0005]

However, according to the structure of the above-mentioned general EL display, if the protection panel is made completely transparent so as not to lower the luminance of the display image, the EL display itself becomes invisible. In addition to seeing through, the circular polarizer on the glass substrate on the display surface side
Due to the reflection of the light emitted through the protection panel, the color appears turbid and the appearance is impaired.

On the other hand, if the protective panel is colored in a translucent color such as smoke to prevent this, the brightness of the display image is reduced by that much.

Therefore, in the above-described general EL display configuration, it is difficult to achieve both good appearance and high brightness of the display image, regardless of whether the protection panel is made of a transparent color or a translucent color. This has been a bottleneck in applying EL displays to display panels in fields such as car audio equipment where design elements are regarded as important.

[0008] The present invention has been made in view of the above circumstances,
An object of the present invention is to provide an EL display capable of achieving both good appearance and high brightness of a display image even when applied to a display panel or the like of a car audio device in which design elements are important. And a display device using the same.

[0009]

According to the present invention, there is provided a display apparatus comprising:
In a display device, a display image displayed on a display surface of a display is viewed through an image light of the display image emitted from the display surface and transmitted through the circularly polarizing plate through a protection panel covering the display surface. Wherein the circularly polarizing plate is arranged on a surface of the protection panel facing the display surface of the EL display.

According to a second aspect of the present invention, in the display device of the first aspect of the present invention, a reflection surface of the circularly polarizing plate facing the display surface of the EL display is provided. Prevention treatment was applied.

Further, according to the display device of the present invention described in claim 3, in the display device of the present invention described in claim 1, a surface of the circularly polarizing plate facing the display surface of the EL display is prevented. A glare treatment was performed.

According to the display device of the first aspect of the present invention, since the circularly polarizing plate is disposed on the surface of the protection panel facing the display surface of the EL display, the protection panel can be made of PMMA having high transparency. Even when formed by a PC, the opaque circular polarizing plate blocks the view of the EL display entity behind it.

According to the display device of the present invention described in claim 2, in the display device of the present invention described in claim 1, antireflection treatment is performed on the surface of the circularly polarizing plate facing the display surface of the EL display. Therefore, even if the image light of the display image emitted from the display surface of the EL display reaches the circularly polarizing plate, the image light is not reflected on the display surface side of the EL display.

Further, according to the display device of the present invention described in claim 3, in the display device of the present invention described in claim 1, the surface of the circularly polarizing plate facing the display surface of the EL display has an antiglare treatment. Is applied, even if the image light of the display image emitted from the display surface of the EL display reaches the circularly polarizing plate, the reflected light of the image light becomes diffused light, and is reflected by the circularly polarizing plate. The display image formed by the image light is not formed as a virtual image on the display surface of the EL display.

In addition, according to the display device of the present invention described in claim 3, in the display device of the present invention described in claim 1, the display image displayed on the display surface of the EL display is an image formed by a dot matrix. In this case, when the image light of each dot reaches the surface of the circularly polarizing plate facing the display surface of the EL display, it becomes diffused light and a part of the light is transmitted through the circularly polarizing plate and the protection panel.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the display device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing the entire configuration of a display device according to a first embodiment of the present invention. The display device of the first embodiment indicated by reference numeral 1 in FIG. The EL display 5 mounted on the display panel 3 is provided with a decorative panel 7 located in front of the display surface 5a.
Resin (PMMA or PC) fitted into the opening 7a
, Etc.).

The display surface 5a of the EL display 5
Are further disposed on a rear-side glass substrate, a thin-film electrode layer serving as a cathode, a light-emitting layer, and a transparent electrode layer such as ITO serving as an anode (all not shown), which are sequentially laminated on the printed wiring board 3. It is constituted by the surface of the front-side glass substrate laminated in pairs with the rear-side glass substrate.

Next, the detailed structure of the display device 1, particularly the protection panel 9 will be described in detail with reference to an enlarged sectional view of a main part shown in FIG.

As shown in FIG. 2, the front surface 13a of the circular polarizing plate 13 is adhered to the back surface of the protection panel 9 facing the display surface 5a of the EL display 5 by a transparent adhesive 11. The back surface 13b of the circularly polarizing plate 13 facing the display surface 5a of the EL display 5 is anti-reflection (non-reflective, hereinafter referred to as “A”) by a transparent adhesive 11.
R ". ) The film 15 is stuck.

Next, the operation of the display device 1 according to the first embodiment configured as described above will be described.

In the display device 1 of the first embodiment,
When a voltage is applied between the thin-film electrode layer, which is a cathode and an anode, and the transparent electrode layer, the light-emitting substance in the light-emitting layer is excited to emit light, thereby forming image light of a desired display image. The AR film 1 emitted from the display surface 5a of the EL display 5 and stuck on the back surface of the protection panel 9 on the circularly polarizing plate 13
Reach 5

Then, the image light of the display image that has reached the AR film 15 passes through the AR film 15 and the adhesive 11, reaches the back surface 13b of the circularly polarizing plate 13, and further from the back surface 13b to the front surface 13a. The light passes through the circularly polarizing plate 13 and, when transmitted through the circularly polarizing plate 13, corrects the polarization of the image light to improve the contrast ratio of the displayed image.

Further, the light is transmitted through the circularly polarizing plate 13 and its surface 1
The image light of the display image that has reached 3a passes through the adhesive 11 and the protection panel 9 and is emitted forward from the surface of the protection panel 9, and the emitted image light causes the display image to be displayed from the surface side of the protection panel 9 Is visually recognized on the display surface 5a of the EL display 5.

In this case, since the circularly polarizing plate 13 is adhered to the rear surface of the transparent resin protective panel 9 by the transparent adhesive 11, the circularly polarizing plate looks turbid when viewed from the front side of the protective panel 9. 13, the originally transparent protective panel 9 located in front of it also looks cloudy and looks like smoke, and the EL display 5 located behind the protective panel 9 to the circularly polarizing plate 13 is emitted from its display surface 5 a. Except for the real image portion of the display image that looks brilliant with the image light,
The view is obstructed, making it invisible.

However, since the protection panel 9 is made of a transparent resin, the image light of the display image is not attenuated by the transmission of the protection panel 9 and the brightness of the display image does not decrease.

The protection panel 9 protects the image light of the display image emitted from the display surface 5a of the EL display 5 by the AR film 15 adhered to the back surface 13b of the circularly polarizing plate 13.
The reflection from the side of the protective panel 9 to the display surface 5a is prevented, and the reflected image light from the protection panel 9 side
No image is formed on a.

As described above, according to the first embodiment, a display image displayed on the display surface 5a of the EL display 5 is converted into image light emitted from the display surface 5a and transmitted through the circular polarizer 13 in front of the display image. The display device 1 is seen through the protection panel 9 disposed in front of the EL display 5
, The front surface 13a of the circularly polarizing plate 13 is adhered to the back surface of the protection panel 9 facing the display surface 5a of the EL display 5 with a transparent adhesive 11.

For this reason, the presence of the turbid circular polarizing plate 13 prevents the EL display 5 from being seen through the protection panel 9, and maintains the good appearance of the display device 1 while maintaining the appearance of the protection panel 9 itself. By using a transparent resin, it is possible to realize a configuration in which the image light of the display image is not attenuated when transmitted through the protection panel 9, and the display image can be maintained at a high luminance.

Although the structure in which the AR film 15 is adhered to the back surface 13b of the circularly polarizing plate 13 with the transparent adhesive 11 may be omitted, the AR film 15 may be used as in the display device 1 of the first embodiment. If it is configured to stick, EL
The reflection of the image light of the display image emitted from the display surface 5a of the display 5 from the protection panel 9 side to the display surface 5a is prevented, and the virtual image of the display image is formed together with the real image by the formation of the reflected image light. This is advantageous because it can be prevented from being visually recognized on the display surface 5a.

Next, a display device according to a second embodiment of the present invention will be described with reference to FIG.

FIG. 3 is an enlarged sectional view of a main part showing a detailed structure of a display device 1A according to a second embodiment of the present invention, particularly, a protective panel 9 portion. The configuration is different from that of the display device 1 of the first embodiment in that the film 17 is attached to the back surface 13b of the circularly polarizing plate 13, and all other points are the display of the first embodiment. The configuration is the same as that of the device 1.

In the display device 1A of the second embodiment configured as described above, similarly to the display device 1 of the first embodiment, the image light of the desired display image emitted from the display surface 5a of the EL display 5 is provided. But AG film 17,
The light passes through the adhesive 11, the circularly polarizing plate 13, the adhesive 11, and the protection panel 9, and is emitted forward from the surface of the protection panel 9, and is displayed from the surface side of the protection panel 9 by the emitted image light. The actual image is the display surface 5 of the EL display 5
a.

Then, due to the presence of the circularly polarizing plate 13 adhered to the back surface of the protective panel 9, both the circularly polarizing plate 13 and the originally transparent protective panel 9 located in front of the circularly polarizing plate 13 are viewed from the front side of the protective panel 9. It looks cloudy and smoked, and E is located behind the protective panel 9 to the circularly polarizing plate 13.
The L display 5 becomes invisible because the view is blocked except for the real image portion of the display image, and the EL display 5
Of the display image on the display surface 5a does not decrease because the protection panel 9 is made of a transparent resin.

In the display device 1A of the second embodiment, since the AG film 17 is adhered to the back surface 13b of the circularly polarizing plate 13, the image of the display image emitted from the display surface 5a of the EL display 5 is obtained. When the light reaches the AG film 17, the image light is reflected toward the display surface 5a on the back surface of the AG film 17 facing the display surface 5a.

In this case, since the image light of the display image becomes diffused light when reflected on the back surface of the AG film 17, the display image formed by the image light reflected from the back surface of the AG film 17 is not displayed on the display surface of the EL display 5. No image is formed on 5a as a visible virtual image.

According to the display device 1A of the second embodiment having such a configuration, similarly to the display device 1 of the first embodiment, due to the presence of the circularly polarizing plate 13 which looks turbid, the EL display 5 is provided through the protection panel 9. The protection panel 9 itself is made of a transparent resin so that the image light of the display image is not attenuated when transmitted through the protection panel 9 while maintaining the good appearance as the display device 1 so as not to be seen through. As possible, the display image can be kept at a high luminance.

In addition, according to the display device 1A of the second embodiment, since the AG film 17 is adhered to the back surface 13b of the circularly polarizing plate 13, the light is emitted from the display surface 5a of the EL display 5 and the AG film 17 is emitted. When the image light of the display image arriving at the back surface of the light is reflected on the display surface 5a side, the image light is used as diffused light, and the virtual image of the display image by the reflected image light is E
By not forming an image on the display surface 5a of the L display 5, it is possible to prevent a virtual image of the display image from being visually recognized together with the real image on the display surface 5a.

By the way, in the display device 1A of the second embodiment, even when the image light of the display image that has reached the back surface passes through the AG film 17, the image light becomes diffused light in the same manner as the reflected image light. Therefore, when the EL display 5 is of the dot matrix type, the boundaries between the dots constituting the display image seen through the protection panel 9 are prevented from being clearly recognized, and the boundaries are blurred to improve the display quality. Can be further improved.

In the display device 1 of the first embodiment described above, the case where the AR film 15 is adhered to the back surface 13b of the circularly polarizing plate 13 on the back surface of the protection panel 9 has been described. If it is permissible due to the configuration and installation environment, a low reflection (low reflection, LR) film (not shown) is attached to the back surface 13b of the circularly polarizing plate 13 with a transparent adhesive 11 instead of the AR film 15. Of course, you may wear it.

The AR film 15, the AG film 17, and the LR film (not shown) are not limited to those adhered to the back surface 13b of the circularly polarizing plate 13 by the transparent adhesive 11, but may be formed by vapor deposition or coating. Back surface 1 of circularly polarizing plate 13
3b, or may be formed integrally with the back surface 13b of the circularly polarizing plate 13 instead of using a member separate from the circularly polarizing plate 13.

Further, it is needless to say that the present invention can be applied to a display device using any of so-called organic EL and inorganic EL displays.

[0043]

As described above, according to the display device of the first aspect of the present invention, the display image displayed on the display surface of the EL display is emitted from the display surface to form the circularly polarizing plate. In a display device that allows the image light of the transmitted display image to be viewed through a protection panel covering the display surface, the circular polarizing plate is provided on a surface of the protection panel facing the display surface of the EL display. It was configured to be arranged.

For this reason, the presence of the turbid circular polarizing plate prevents the EL display from being seen through the protection panel, thereby maintaining the good appearance of the display device, and changing the protection panel itself to a highly transparent PMMA or the like. It is possible to realize a configuration in which the image light of the display image is not attenuated when transmitted through the protection panel, and can maintain the display image at high luminance.

According to the display device of the present invention described in claim 2, in the display device of the present invention described in claim 1, the surface of the circularly polarizing plate facing the display surface of the EL display. The anti-reflection treatment is applied to the.

For this reason, a circularly polarizing plate, whose design is more difficult to match the refractive index with the refractive index of air existing between the protective panel and the EL display than the protective panel, is opposed to the display surface of the EL display. Even if it is arranged on the surface of the protection panel, it is necessary to reliably prevent the image light of the display image from being reflected on the circularly polarizing plate, which causes the virtual image of the display image to be displayed on the display surface of the EL display. Can be.

Further, according to the display device of the present invention described in claim 3, in the display device of the present invention described in claim 1, the EL device of the circularly polarizing plate is provided.
The antiglare treatment was performed on the surface of the display facing the display surface.

For this reason, a circularly polarizing plate, whose design is more difficult to match the refractive index with the refractive index of air existing between the protective panel and the EL display than the protective panel, faces the display surface of the EL display. Image light of the display image reflected by the circularly polarizing plate,
It is possible to surely prevent a real image of a display image from being formed as a visible virtual image on a portion of the display surface of the display remote from the real image of the display image and being displayed on the display surface of the EL display together with the real image of the display image. it can.

In addition, when the display image displayed on the display surface of the EL display is an image based on a dot matrix, the image light of each dot is diffused at the time of arrival at the circularly polarizing plate and the boundary between adjacent dots is diffused. Can be blurred so that even if the dot interval is wide, it is visually inconspicuous.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically illustrating an entire configuration of a display device according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part showing a detailed structure of a display panel in FIG.

FIG. 3 is an enlarged cross-sectional view of a main part showing a detailed structure of a display device according to a second embodiment of the present invention, particularly, a protection panel portion.

[Explanation of symbols]

1, 1A Display device 5 EL display 5a EL display display surface 9 Protective panel 13 Circular polarizing plate 13b Back surface of circular polarizing plate (surface of circular polarizing plate facing display surface of EL display) 15 AR film (anti-reflection treatment) 17 AG film (anti-glare treatment)

Claims (3)

[Claims] 1. A display image displayed on a display surface of an EL display is transmitted through a protective panel covering the display surface by image light of the display image emitted from the display surface and transmitted through a circularly polarizing plate. A display device, wherein the circularly polarizing plate is disposed on a surface of the protection panel facing the display surface of the EL display. 2. The display device according to claim 1, wherein an anti-reflection process is performed on a surface of said circularly polarizing plate facing said display surface of said EL display. 3. The display device according to claim 1, wherein a surface of the circularly polarizing plate facing the display surface of the EL display is subjected to an anti-glare treatment.