JPH11260561A - Electroluminescent lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the separation of a transparent film from a transparent electrode layer from occurring due to the shock at the time of disconnection or the heat shock under a high temperature and high humidity condition by improving the adhesion between the transparent film and the transparent electrode by interposing a resin layer between the transparent film and the transparent electrode. SOLUTION: A resin layer 2 having a thickness of approximately 5-10 μm is formed on a transparent film 1 formed from PET or the like by performing screen printing of a thermoplastic polyester resin. Next, a transparent electrode layer 3 having a thickness of approximately 8-15 μm is formed from a material made by dispersing conductive powder such as indium oxide in a thermosetting acrylic resin or the like by means of screen printing. In addition, a luminescent layer 4 formed by dispersing a phosphor made by activating zinc oxide by copper in a resin is formed in a thickness of approximately 35-45 μm, then a reflective insulating layer 5 is formed in a thickness of approximately 10-15 μm, a back side electrode 6 is formed in a thickness of approximately 10-20 μm and an insulating layer 7 is formed in a thickness of approximately 10-20 μm, sequentially. If a white pigment or a fluorescent pigment is added to the resin layer 2, the conversion of a body color or a luminescent color can easily performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electroluminescent lamp,
In particular, the present invention relates to an electroluminescent lamp used as a backlight of a liquid crystal display.

[0002]

2. Description of the Related Art Conventionally, as shown in a sectional view of FIG. 5, an electroluminescent lamp 50 has a light emitting layer 42 on a transparent conductive film 41 in which a transparent electrode 41b such as ITO is formed on a transparent film 41a.
A structure in which the reflective insulating layer 43 and the back electrode 44 are sequentially laminated and printed is generally used.

[0003]

Here, when a transparent conductive film in which a transparent electrode such as ITO is deposited on a transparent film is used, since the transparent electrode is very thin, micro cracks are generated due to heat shrinkage due to drying during film formation. There was a problem that the resistance value of the transparent electrode increased due to the occurrence. In addition, since the film is a vapor-deposited film, there is a problem such as an increase in resistance due to oxidation and reduction reactions. Further, there is a problem of insufficient mechanical strength such as breaking or breaking due to handling in the process.

In Japanese Patent Application Laid-Open No. 9-35873, a transparent electrode in which a conductive powder is dispersed in a thermosetting or photocurable resin is formed by printing on a transparent film, and a light emitting layer is formed thereon.
An example in which an electroluminescent lamp is formed by printing a reflective insulating layer and a back electrode is disclosed. However, since the thermosetting or photo-curing resin is used for the transparent electrode, the adhesiveness to the transparent film is poor, and the impact at the time of cutting and molding, and the environment such as high temperature or high humidity and heat shock. There was a problem that the transparent film and the transparent electrode layer peeled off due to the shrinkage of the base film or the resin below. In addition, by using a thermoplastic resin having good adhesion to the transparent film for the transparent electrode, the adhesion to the transparent film is improved. However, when forming a light-emitting layer made of a solvent-based ink on the transparent electrode, a transparent solvent is used. There has been such a problem that the electrodes are eroded, the resistance value is increased, and the characteristics of the electroluminescent lamp are significantly reduced.

[0005]

SUMMARY OF THE INVENTION The present invention has been proposed in order to solve the above-mentioned problems and to provide a highly reliable electroluminescent lamp, in which a conductive film such as a transparent film or indium oxide is heated. In an electroluminescent lamp consisting of a laminated transparent electrode, light-emitting layer, reflective insulating layer, and back electrode dispersed in a curable resin, a thermoplastic resin layer between the transparent film and the transparent electrode, or adhesion to the polyester film It is characterized by having a good resin layer interposed. Also,
An electroluminescent lamp in which a transparent film, a resin layer, a transparent electrode, a light emitting layer, a reflective insulating layer, and a back electrode are laminated, is characterized in that a white pigment or a fluorescent pigment is mixed in the resin layer. Also, in an electroluminescent lamp in which a transparent film, a resin layer, a transparent electrode, a light emitting layer, a reflective insulating layer, and a back electrode are laminated, the resin layer is made of a rubbery resin having a high elastic modulus such as fluoro rubber, urethane rubber, silicon rubber, It is characterized by consisting of.

According to the present invention, the adhesiveness between the transparent film and the transparent electrode can be improved by interposing a resin layer between the transparent film and the transparent electrode. In an environment such as heat shock, a highly reliable electroluminescent lamp can be provided in which the transparent film and the transparent electrode layer do not peel off due to shrinkage of the base film or the resin. Further, by adding a white pigment or a fluorescent pigment to the resin layer, in addition to the above-described effects, there is an effect that the body color can be easily changed and the emission color can be easily converted. In addition, by employing a resin having a high elastic coefficient, the surface strength against back surface pressing can be improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of an electroluminescent lamp according to the present invention will be described with reference to FIG. The electroluminescent lamp 10 of the present invention has a structure as shown in the sectional view of FIG. First, a thermoplastic polyester resin is screen-printed on a transparent film 1 made of PET or the like to form a resin layer 2 with a thickness of 5 to 10 μm. Next, a transparent electrode layer 3 in which a conductive powder such as indium oxide is dispersed in a thermosetting resin (for example, an acrylic resin) is formed by screen printing.
The light emitting layer 4 was formed in a thickness of about 15 μm, and further a phosphor in which zinc sulfide was activated by copper was dispersed in the resin. The light emitting layer 4 was 35 to 45 μm, and a white high dielectric substance such as barium titanate was dispersed in the resin. The reflective insulating layer 5 is 10 to 15 μm, the back electrode 6 made of a conductive paste such as silver or carbon is 10 to 20 μm, and the insulating layer 7 is 10 to 15 μm.
An electroluminescent lamp 10 is obtained by sequentially forming a screen having a thickness of about 20 μm by screen printing.

Here, since the thermoplastic polyester resin layer 2 is interposed between the transparent film 1 and the transparent electrode 3, the adhesion between the transparent film 1 and the transparent electrode 3 is improved,
The transparent film 1 and the transparent electrode 3 do not peel off due to an impact at the time of cutting, or even due to shrinkage of the base film or resin under an environment such as high temperature or high humidity and heat shock. Further, since the transparent electrode 3 is printed on the resin layer 2, the film quality of the transparent electrode is improved, and a uniform and low-resistance transparent electrode can be obtained. Although the resin layer 2 is made of a polyester resin, any resin may be used as long as it has good adhesion to a transparent film as a base material such as a thermoplastic urethane resin or an acrylic resin.

Next, a second embodiment of the present invention will be described with reference to FIG. First, as in the first embodiment, as shown in FIG. 2, a transparent film 11 made of PET or the like is used.
On the above, for example, an ink obtained by adding 5 wt% of titanium oxide to a thermoplastic polyester resin by weight ratio is screen-printed to form a white resin layer 12 with a thickness of 5 to 10 μm. Next, a transparent electrode layer 13 in which a conductive powder such as indium oxide is dispersed in a thermosetting resin (eg, an acrylic resin) is formed to a thickness of 8 to 15 μm by screen printing, and zinc sulfide is activated with copper. The light emitting layer 14 in which the phosphor thus obtained is dispersed in the resin is 35
The reflective insulating layer 15 in which a white high dielectric substance such as barium titanate is dispersed in a resin is 10 to 15 μm, the back electrode 16 made of a conductive paste such as silver or carbon is 10 to 20 μm,
The insulating layer 17 is sequentially formed with a thickness of 10 to 20 μm by screen printing to obtain the electroluminescent lamp 20.

Generally, when a transparent electrode is formed by printing,
Since the body color of indium oxide or tin oxide, which is a transparent conductive powder, is yellow or blue, the transparent electrode is also colored yellow or blue. When this electroluminescent lamp 20 is used as a backlight of an anti-transmissive liquid crystal. Although the contrast deteriorates, by mixing a white pigment into the resin layer 12 as described above, the adhesion between the transparent film 11 and the transparent electrode 13 can be improved, and the body color of the electroluminescent lamp 20 can be whitened. Of the backlight can be improved. Further, since the white resin layer 12 is provided in a portion where the electric field is not applied, the brightness is not extremely reduced.

Next, a third embodiment of the present invention will be described with reference to FIG. First, as shown in FIG.
On a transparent film 21 made of, for example, an ink obtained by adding 30% by weight of a pink fluorescent pigment (for example, FA001 manufactured by Schinloich) to a thermoplastic polyester resin by screen printing to form a color conversion resin layer 22 of 5% by weight. It is formed with a thickness of 1010 μm. Next, a transparent electrode layer 23 in which conductive powder such as indium oxide is dispersed in a thermosetting resin (for example, an acrylic resin) is formed to a thickness of 8 to 15 μm by screen printing, and zinc sulfide is activated with copper. The light emitting layer 24 in which the phosphor is dispersed in a resin is 35 to 45 μm, and the reflective insulating layer 25 in which a white high dielectric substance such as barium titanate is dispersed in the resin is 10 to 45 μm.
An electroluminescent lamp 30 is obtained by sequentially forming screen electrodes of 15 μm, a back electrode 26 made of a conductive paste such as silver or carbon, with a thickness of 10 to 20 μm, and an insulating layer 27 with a thickness of 10 to 20 μm.

According to the present embodiment, by mixing a pink fluorescent pigment into the resin layer 22, the adhesion between the transparent film 21 and the transparent electrode 23 is improved and the electroluminescent lamp is used.
30 emission colors can be converted to white. Further, since the color conversion resin layer 22 is provided in a portion where no electric field is applied, color conversion can be performed without significantly lowering luminance.
Although a pink fluorescent pigment is used as the fluorescent pigment, it can be converted to an arbitrary luminescent color by mixing an arbitrary fluorescent pigment with the resin layer.

Next, a fourth embodiment of the present invention will be described with reference to FIG. First, as shown in FIG.
For example, urethane rubber having a rebound resilience of about 30% is screen-printed on a transparent film 31 made of
It is formed with a thickness of 1010 μm. Next, a transparent electrode layer 33 in which a conductive powder such as indium oxide is dispersed in a thermosetting resin (for example, an acrylic resin) is screen-printed to a thickness of 8 to 15 μm.
35-45 μm light-emitting layer 34 in which phosphor with zinc sulfide activated by copper is dispersed in resin, and reflective insulation in which white high-dielectric substance such as barium titanate is dispersed in resin. The layer 35 is 10 to 15 μm, the back electrode 36 made of a conductive paste such as silver or carbon is 10 to 20 μm, and the insulating layer 37 is 10 to 20 μm.
The electroluminescent lamp 40 is obtained by sequentially forming the same with a thickness of the screen printing.

According to this embodiment, since the urethane rubber having a high elastic coefficient is used for the resin layer 32, the adhesion between the transparent film 31 and the transparent electrode 33 is improved, and the electroluminescent lamp is assembled to a liquid crystal or the like. At this time, it is possible to prevent a minute object such as a solder particle or a foreign substance from pressing the back surface of the electroluminescent lamp to deform the film, and prevent the minute object from penetrating and causing a short circuit between the electrodes. In this embodiment, urethane rubber is used for the resin layer. However, any resin may be used as long as it has a rebound resilience of 15% or more and has good adhesion to the base film.

[0015]

According to the present invention, the adhesiveness between the transparent film and the transparent electrode can be improved by interposing a resin layer between the transparent film and the transparent electrode. Alternatively, a highly reliable electroluminescent lamp can be provided in which the transparent film and the transparent electrode layer do not peel off due to shrinkage of the base film or the resin under an environment such as high humidity and heat shock. Further, by adding a white pigment or a fluorescent pigment to the resin layer, it is possible to easily change the body color and convert the emission color in addition to the above-described effects. In addition, by employing a resin having a high elastic coefficient, the surface strength against the back surface pressing by foreign matter can be improved, and a high-quality, low-cost liquid crystal display with a backlight can be provided.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part of an electroluminescent lamp according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of an electroluminescent lamp according to a second embodiment of the present invention.

FIG. 3 is an enlarged sectional view of a main part of an electroluminescent lamp according to a third embodiment of the present invention.

FIG. 4 is an enlarged sectional view of a main part of an electroluminescent lamp according to a fourth embodiment of the present invention.

FIG. 5 is an enlarged sectional view of a main part of a conventional electroluminescent lamp.

[Explanation of symbols]

 1,11,21,31 Transparent film 2,12,22,32 Resin layer 3,13,23,33 Transparent electrode 4,14,24,34 Light emitting layer 5,15,25,35 Reflective insulating layer 6,16, 26,36 Back electrode 7,17,27,37 Insulating layer 10,20,30,40 Electroluminescent lamp

Claims (5)

[Claims] 1. An electroluminescent lamp comprising a transparent film, a transparent electrode, a light emitting layer, a reflective insulating layer, and a back electrode laminated on each other, wherein a resin layer is interposed between the transparent film and the transparent electrode. Electroluminescent lamp. 2. The method according to claim 1, wherein the transparent electrode is formed by dispersing a conductive filler such as indium oxide in a thermosetting resin, and the resin layer is made of a thermoplastic resin. Electroluminescent lamp. 3. The electroluminescent lamp according to claim 1, wherein a white pigment is mixed in the resin layer. 4. The electroluminescent lamp according to claim 1, wherein a fluorescent pigment is mixed in the resin layer. 5. The electroluminescent lamp according to claim 1, wherein the resin layer is made of a rubbery resin having a high elastic modulus such as fluorine rubber, urethane rubber, silicon rubber and the like.