Liquid crystal cells – elements and systems – Particular structure – Having significant detail of cell structure only
Reexamination Certificate
2002-01-14
2003-08-26
Chowdhury, Tarifur R. (Department: 2871)
Liquid crystal cells, elements and systems
Particular structure
Having significant detail of cell structure only
C349S156000
Reexamination Certificate
active
06611312
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a display device, and more particularly, to a flat-face panel display device which sets the pressure in a sealed space defined in the inside of display device lower than the outside pressure.
2. Description of the Related Art
As a display device which exhibits high brightness and high definition, a color cathode ray tube has been widely used. However, along with the progress in the field of information processing equipment and to realize the high quality television broadcasting, the demand for a flat-plate-like display (panel display) which exhibits excellent characteristics such as high brightness and high definition, is light-weighted and can minimize the space has been increasing.
As typical examples, liquid crystal display devices, plasma display devices or the like have been commercialized. Particularly, as display devices which can further enhance high brightness, panel-type display devices of various types such as field emission displays (also referred to as “FEDs” hereinafter) or organic EL displays which are characterized by the low power consumption are expected to be commercialized soon.
Among such panel-type display devices, in a display device which makes a sealed space defined between two panels consisting of a front surface panel and a back surface panel have pressure lower than the ambient atmospheric pressure or a vacuum state, it is necessary to hold a gap between these two panels at a given value and to maintain the air-tightness of the sealed space. To form the sealed space in the gap defined between two opposing panels, it is necessary to insert spacers between inner walls of peripheries of both panels. These spacers may be obtained by coating an adhesive agent (such as a frit glass or the like) using a dispenser, a multiple printing or the like. However, when the gap between both panels is large, it is difficult for the spacers having such a constitution to maintain a given gap since the adhesive agent flows and is deformed. On the other hand, the multiple printing is time consuming.
For example, with respect to the FED having the large gap between both substrates, glass plates are used as the panel material and the gap of the sealed space defined between these glass plates (the front surface panel and the back surface panel) is approximately 1 mm or more. The above-mentioned gap can be formed by fixedly securing the front surface panel and the back surface panel with the outer frame using the adhesive agent.
FIG. 6
is a schematic cross-sectional view for explaining a constitutional example of a field emission display device (FED) as an example of the panel display device of this type. In this field emission display device, peripheral inner walls of a back surface panel
1
and a front surface panel
2
are fixedly secured to each other by means of an outer frame
3
, thus forming a sealed space which is at a reduced pressure or is evacuated in the inside surrounded by the outer frame
3
. The thickness of the outer frame
3
is set to approximately 1 mm and is fixedly secured to the back surface panel
1
and the front surface panel
2
using an adhesive agent
4
.
A cathode electrode
5
, an insulation layer
6
and a grid electrode
7
are formed on an inner surface of the back surface panel
1
, while an anode electrode
8
and a phosphor
9
are formed on an inner surface of the front surface panel
2
. The cathode electrode
5
and the phosphor
9
form a pair and constitute one pixel. In case of a color display, one color pixel is constituted of a group made of three neighboring different phosphors which irradiate lights of different colors (generally, red, green and blue). Here, a partition wall
10
made of insulation material is disposed between respective pixels.
In the FED of this type, electron beams irradiated from the cathode electrode
5
are controlled in response to image information applied to the grid electrode
7
and impinge on the phosphor
9
laminated on the anode electrode
8
thus generating given colors.
FIG. 7
is a developed perspective view for schematically explaining a conventional constitutional example of the back surface panel, the front surface panel and the outer frame shown in FIG.
6
. The outer frame
3
which is interposed between the back surface panel
1
and the front surface panel
2
is formed of an integral or unitary frame. By coating adhesive agents
3
a,
3
b
which are preferably made of frit glass on respective surfaces of the outer frame
3
which face the inner surfaces of the back surface panel
1
and the front surface panel
2
in an oppose manner using suitable means such as printing or the like, the back surface panel
1
and the front surface panel
2
are fixedly secured to each other thus forming an inner space which constitutes the sealed space which is at a reduced pressure or in a vacuum state.
As literatures which disclose the display devices of this type, Japanese Laid-open Publication 21335/2000, Japanese Laid-open Publication 22782/1996 and the like can be named.
In the above-mentioned prior art, with respect to the display device which adheres and fixedly secures two glass plates using the outer frame, when the display device becomes large-sized, the display device is liable to be broken during handling thereof and this causes waste in processing the material used for the display thus pushing up the manufacturing cost.
To obviate such a problem, a technique which divides the outer frame into a plurality of members and then assembles and adhere these members each other may be considered. However, in such a technique, after adhering, a leaking of the inner pressure is liable to occur at portions where these members are adhered to each other so that it is difficult to maintain the air-tightness. Accordingly, it has been a task of the present invention to solve such a problem.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a display device which can solve the above-mentioned task of the prior art and can maintain the air-tightness of a sealed space while holding a gap between two glass plates at a given value even when the gap is large.
To achieve the above-mentioned object, the present invention provides a display device comprising a front surface panel, a back surface panel and an outer frame, wherein the front surface panel, the back surface panel and the outer frame are fixedly secured to each other by an adhesive agent, and a sealed space formed in the inside surrounded by the front surface panel, the back surface panel and the outer frame is set at a pressure lower than the outside pressure, the improvement being characterized in that the outer frame is comprised of a plurality of wall members and portions of at least some neighboring wall members which are engaged with each other have oblique surfaces at least partially, a crossing angle made by a normal line of the oblique surfaces and a normal line of the front surface panel or the back surface panel is set to an acute angle, and both oblique surface portions which are engaged with each other are fixedly secured to each other by way of the adhesive agent inserted therebetween.
Due to such a constitution, in the sealing step, the adhesive agent is coated on the oblique surface portions of the outer frames which are engaged with each other, pressure is applied to the oblique surface portions in the direction toward the front surface panel and the back surface panel, and the adhesive agent is melt by heating the adhesive agent at a high temperature. In this case, since the crossing angle made by the normal line of the above-mentioned oblique surface and the normal line of the front surface panel or the back surface panel is set to an acute angle so that a state in which the pressure is applied to both oblique surface portions is realized. Accordingly, the adhesive agent inserted between these oblique portions can be generally easily extended so that the reliable sealing is obtained. Accordingly, the leak
Hirasawa Shigemi
Kawasaki Hiroshi
Kijima Yuuichi
Chowdhury Tarifur R.
Hitachi , Ltd.
LandOfFree
Display device including outer frame with some neighboring... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Display device including outer frame with some neighboring..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Display device including outer frame with some neighboring... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3128968