JP5012609B2 - Display device - Google Patents

Description

  The present invention relates to a display device provided with a protective cover, and is particularly suitable for application to a liquid crystal display device.

For example, in a display device for outdoor installation using liquid crystal, it is necessary to protect the display panel from external impacts and flooding due to rain, so the display surface of the display panel is covered with a transparent protective cover made of resin or glass. In many cases, the cover is further waterproofed around the protective cover.

When a protective cover is placed on the display surface of the display panel, there is an air layer between the display panel and the protective cover, so external light incident on the display surface is reflected on the front and back surfaces of the transparent protective cover and the flat panel surface. The problem that visibility falls will arise.

In order to solve such a problem, there is one in which a transparent resin or the like is filled in a gap between the display panel and the protective cover, or a light-transmitting adhesive sheet is disposed (for example, see Patent Document 1). .

JP 2006-290960 A

In the system in which the liquid transparent resin is filled in the gap between the display panel and the protective cover, the resin enters the display panel through the gap between the frame that holds the display panel and the display panel, and the resin that has entered the interior is visually recognized. There was a problem such as. In order to prevent this problem, it is necessary to form a sealing material or the like that suppresses the penetration of the resin in the gap between the frame and the display panel, which increases the number of work steps.

In addition, a transparent adhesive sheet is arranged in the gap between the display panel and the protective cover, and the protective cover is attached to the frame arranged to cover the periphery of the display surface of the display panel and the display surface of the display panel. Since a level difference occurs, bubbles are mixed in the vicinity of the level difference when the protective cover is bonded with the transparent adhesive sheet, and the display quality is remarkably lowered. In order to suppress bubbles, it is necessary to dispose a transparent adhesive sheet only on the display surface of the display device. However, in this configuration, the frame, the display panel, and the protective cover cannot be fixed. There was a problem that the strength decreased.

The present invention has been made in view of such problems, and by not using a liquid resin, the intrusion of the resin into the display panel is eliminated, and bubbles are also generated in the vicinity of the step portion of the frame. An object of the present invention is to provide a display device that does not deteriorate display quality by being suppressed.

The present invention relates to a display panel having a display surface, an opening formed at a position corresponding to the display surface, a frame for holding the periphery of the display panel, a protective cover for protecting the display surface, a display surface and a protective cover A display device including two transparent adhesive sheets disposed in a gap between the display panel and the frame covering a peripheral portion of the display surface of the display panel, and the display surface of the two transparent adhesive sheets. The thickness of the first transparent adhesive sheet adjacent to the frame is substantially the same as the thickness of the end portion of the frame that covers the periphery of the display surface of the display panel, and the first transparent adhesive sheet is attached to the frame. formed is formed smaller than the opening, a second transparent adhesive sheet adjacent to the protective cover, characterized in that bonding the said protective cover and said frame and said first transparent adhesive sheet To.

  According to the present invention, it is possible to obtain a display device that does not deteriorate the display quality without generating bubbles in the vicinity of the step of the frame on the display surface of the display panel. In addition, by not using a resin on the liquid, the manufacturing method is simplified because the handling at the time of bonding is facilitated, and the impact strength of the display device is improved because the frame can also be fixed with a transparent adhesive sheet. be able to.

Embodiment 1 FIG.
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a display device according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view of another display device according to Embodiment 1 of the present invention.

In FIG. 1, a display panel 1 using, for example, a liquid crystal is composed of an insulating substrate 2 on which a thin film transistor array or the like is formed, and a counter substrate 3 arranged to face the insulating substrate 2 with the liquid crystal interposed therebetween. Yes. Polarizing plates 4 and 5 are attached to the outer surfaces of the insulating substrate 2 and the counter substrate 3 in the display panel 1. In the figure, the outer surface of the counter substrate 3 corresponds to the display surface, an opening is formed at a position corresponding to the display surface, and a frame 6 that holds the periphery of the display surface is disposed. Further, the display panel 1 is mounted with a driving circuit, a circuit board, and the like for driving the liquid crystal, but this is not shown in the present embodiment.

In the display panel 1, a planar light source device (not shown) is arranged on the outer surface side of the insulating substrate 2 (lower side in the drawing). The frame 6 is fitted with the planar light source device to constitute a display device. The size of the opening of the frame 6 is smaller than the size of the polarizing plate 5 of the counter substrate, and the end of the frame 6 is arranged on the polarizing plate 5.

A protective cover 4 is disposed on the polarizing plate 5 of the counter substrate 3, and two transparent adhesive sheets are disposed in the gap between the polarizing plate 5 and the protective cover 7. Of the two transparent adhesive sheets, the size of the first transparent adhesive sheet 8 adjacent to the counter substrate 3 is smaller than the opening of the frame 6 by a predetermined amount (about 0.5 to 1.0 mm). . Further, the thickness of the first transparent adhesive sheet 8 is substantially the same as the thickness of the end portion of the frame 6 that covers the periphery of the display surface of the display panel. The second transparent adhesive sheet 9 adjacent to the protective cover 7 is disposed above the first transparent adhesive sheet 8 and the frame 6 and is formed larger than the opening of the frame 6. The polarizing plate 5 and the protective cover 4 of the frame 6 and the counter substrate 3 are bonded via the sheet 8.

As described above, the size of the first transparent adhesive sheet 8 is made smaller than the opening of the frame 6, and the thickness is substantially the same as the thickness of the end portion of the frame 6 that covers the periphery of the display surface of the display panel. Thus, when the display panel 1 and the protective cover 7 are bonded together with the second transparent adhesive sheet 9, the step between the upper surface of the end portion of the frame 6 and the upper surface of the polarizing plate 5 of the counter substrate 3 can be eliminated. Bubbles resulting from the step can be suppressed, and a display device with excellent display quality can be obtained. Furthermore, since the frame 6 can also be fixed by the second transparent adhesive sheet 9, the impact strength of the display device can be improved. Here, the protective cover 7 is not particularly limited as long as it is a transparent material that can protect the display portion of the display panel 1, and an insulating material such as glass or acrylic can be applied. It is preferable to use tempered glass that has been applied.

Next, FIG. 2 shows a cross-sectional view of another display device in this embodiment. The difference from FIG. 1 is that the size of the polarizing plate 5 of the counter substrate 3 is smaller than the size of the opening formed in the frame 6. Therefore, in FIG. 2, the end portion of the frame 6 that covers the peripheral portion of the display surface of the display panel is directly disposed on the counter substrate 3. Thus, by disposing the polarizing plate 5 of the counter substrate 3 in the opening of the frame 6, the step between the upper surface of the end portion of the frame 6 and the upper surface of the polarizing plate 5 on the counter substrate can be reduced ( Compared with FIG. 1 above, it is possible to reduce the step by the thickness of the polarizing plate), and the thickness of the first transparent adhesive sheet 8 can be made thinner than in the case of FIG. Therefore, since the thickness of the 1st transparent adhesive sheet 8 can be made thin, it becomes possible to produce a 1st transparent adhesive sheet at low cost.

Embodiment 2. FIG.
A second embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a cross-sectional view of a display device according to Embodiment 2 of the present invention, and FIG. 4 is a cross-sectional view of another display device according to Embodiment 2 of the present invention. 3 and 4, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and differences from the first embodiment will be described.

3, the size of the polarizing plate 5 of the counter substrate 3 is larger than the opening of the frame 6, and the end of the frame 6 is arranged on the polarizing plate 5 (similar to FIG. 1). Constitution). Further, the first transparent adhesive sheet 8 is formed to be smaller than the opening of the frame 6, and the thickness thereof is a predetermined amount (about 0.1 to 0.2 mm) than the thickness of the end of the frame 6. It is preferable that the thickness is larger.

Next, FIG. 4 shows a cross-sectional view in which the protective cover 7 is attached to the display device shown in FIG. 3 via the second transparent adhesive sheet 9. In the figure, since the second transparent adhesive sheet 9 bonds the frame 6 and the protective cover 7, the first transparent adhesive sheet 8 is sandwiched between the second transparent adhesive sheet 9, the protective cover 7 and the polarizing plate 5. Therefore, the gap between the frame 6 and the first transparent adhesive sheet 8 can be filled by elastic or plastic deformation.

With the above-described configuration, it is possible to obtain a display device with excellent display quality by suppressing the generation of bubbles by eliminating the gap between the frame 6 and the first transparent adhesive sheet 8.

Embodiment 3 FIG.
A third embodiment of the present invention will be described with reference to FIG. FIG. 5 is a cross-sectional view of a display device according to Embodiment 3 of the present invention. 5, the same components as those in FIGS. 1 to 4 are denoted by the same reference numerals, and differences from the first embodiment and the second embodiment will be described.

  In FIG. 5, the size of the polarizing plate 5 of the counter substrate 3 is larger than the opening of the frame 6. A third transparent adhesive sheet 10 larger than the opening of the frame 6 is disposed on the polarizing plate 5, and the opening end of the frame 6 is disposed on the third transparent adhesive sheet 10. Here, the thickness of the third transparent adhesive sheet is not particularly limited, and may be equal to or thicker than the thickness of the frame 6. Further, the first transparent adhesive sheet 8 is formed smaller than the opening of the frame 6 and is sandwiched between the second transparent adhesive sheet 9 and the third transparent adhesive sheet 8 on the display panel 1. Yes.

  In the present embodiment, in the final form in which each sheet is bonded, since the third transparent adhesive sheet 10 receives a force to be crushed by the frame 6 and the first transparent adhesive sheet 8, the frame is elastically or plastically deformed. The gap formed by the open end of 6 and the first transparent adhesive sheet 8 is filled. Similarly, the second transparent adhesive sheet 9 is also elastically or plastically deformed when bonded. By adhering these deformations to the side surface of the first transparent adhesive sheet 8, the gap between the opening end of the frame 6 and the first transparent adhesive sheet 8 can be filled. Here, the size of the first, second and third transparent pressure-sensitive adhesive sheets is such that the second pressure-sensitive adhesive sheet> the third pressure-sensitive adhesive sheet> the first pressure-sensitive adhesive sheet, and further the opening of the frame 6. The relationship including the size is such that the second adhesive sheet> the third adhesive sheet> the opening of the frame> the first adhesive sheet is more reliable than the opening end of the frame 6 and the first transparent adhesive. It is possible to fill the gap with the sheet, which is preferable.

  With the above-described configuration, by completely filling the opening of the frame with the transparent adhesive sheet, it is possible to suppress the generation of bubbles in the vicinity of the opening of the frame and obtain a display device with excellent display quality.

Although the display device using liquid crystal has been described as the above embodiment, the present invention is not limited to this, and is applicable not only to a display device using an electroluminescence (EL) element but also a display device. The present invention can be applied to any display device in which the panel is held by a frame having an opening and a protective cover is disposed on the display panel.

It is sectional drawing of the display apparatus in Embodiment 1 of this invention. It is sectional drawing of the other display apparatus in Embodiment 1 of this invention. It is sectional drawing of the display apparatus in Embodiment 2 of this invention. It is sectional drawing of the other display apparatus in Embodiment 2 of this invention. It is sectional drawing of the display apparatus in Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display panel, 2 Insulating substrate, 3 Opposite substrate, 4 Polarizing plate of insulating substrate, 5 Polarizing plate of opposing substrate, 6 Frame, 7 Protective cover, 8 1st transparent adhesive sheet, 9 2nd transparent adhesive sheet 10 Third transparent adhesive sheet

Claims (4)

A display panel having a display surface;
An opening is formed at a position corresponding to the display surface, and a frame that holds a peripheral portion of the display panel;
A protective cover for protecting the display surface;
Two transparent adhesive sheets disposed in a gap between the display surface and the protective cover;
A display device comprising :
The frame covers the periphery of the display surface of the display panel,
Of the two transparent adhesive sheets, the thickness of the first transparent adhesive sheet adjacent to the display surface is substantially the same as the thickness of the end portion covering the display surface periphery of the display panel in the frame,
The first transparent adhesive sheet is formed smaller than the opening formed in the frame,
The display device , wherein the second transparent adhesive sheet adjacent to the protective cover adheres the frame, the first transparent adhesive sheet, and the protective cover . The thickness of the first transparent adhesive sheet, the display device according to claim 1, wherein a is a predetermined amount larger than the thickness of the frame. Wherein between the two transparent pressure-sensitive adhesive sheet and the display panel, the display device according to claim 1 or 2, characterized in that it comprises a third transparent adhesive sheet. It said third transparent adhesive sheet, the display device according to claim 3, characterized in that it is larger than the opening formed in the frame.

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