JP2002110346A - Electroluminescent lamp and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly bright electroluminescent lamp that is suitable for the IC inverter of a step-up type of the conventional technology. SOLUTION: The electroluminescent lamp 1 comprises a luminous layer 8 composed of a phosphor 4, a binder 5 and a resin layer 7 having a smaller dielectric constant than the binder 5, and the resin layer 7 is arranged between the phosphor 4 and the phosphor 4 by being melted and solidified. And in its manufacturing method, the luminous layer 8 is printed with an ink that has dispersed the phosphor 4 and the resin powder 6 in the binder 5. Then the luminous layer 8 is heated, whereby the resin powder 6 is melted and solidified, and a resin layer 7 is formed between the phosphors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroluminescent lamp and a method of manufacturing the same, and more particularly to a high-luminance electroluminescent lamp suitable for a backlight of a liquid crystal display and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, portable electronic devices such as portable telephones and PHSs have rapidly spread with the progress of the information society.
These electronic devices are equipped with a liquid crystal display,
A small and thin electroluminescent lamp is used as a backlight. This type of electroluminescent lamp 51 has, for example, the structure shown in the cross-sectional view of FIG. 5 and is manufactured as follows. FIG. 5 shows a laminated structure, and the illustration of the lead connection structure is omitted. First, a transparent electrode 53 of 30 to 50 nm is formed on one surface of an insulating transparent film 52 made of PET or the like having a thickness of 100 to 200 μm by vapor deposition, sputtering or the like.
Formed with a thickness of Alternatively, a conductive paste containing ITO powder may be printed to a thickness of several tens of μm.

[0003] Next, a phosphor 54 obtained by activating zinc sulfide with copper.
Using a light emitting layer ink in which (a central particle diameter (median diameter) 20 to 30 μm) and a binder 55 made of fluoro rubber (specific gravity: about 1.8) or the like are dispersed in an organic solvent (for example, isophorone), A light emitting layer 56 is formed on the transparent electrode 53 by screen printing to a thickness of 30 to 50 μm. The binder is made of fluorine rubber (e.g., manufactured by Daikin Industries, Ltd.) with excellent moisture-proof properties to prevent the phosphor from deteriorating due to moisture.
G501). The ink for the light emitting layer is prepared by first dissolving about 0.4 by weight of a fluororubber in the organic solvent 1 to form a binder solution, and then adding the phosphor to the binder solution 1 in a weight ratio of about 1.4. It is dispersed. The viscosity of the ink is adjusted to be suitable for screen printing.

Next, a screen is formed on the light emitting layer 56 by using an ink for a reflective insulating layer in which a white high dielectric powder of barium titanate and fluororubber are dispersed in an organic solvent (for example, isophorone). The reflection insulating layer 57 is formed by printing to a thickness of 10 to 20 μm by printing. The ink for the reflective insulating layer is prepared by first dissolving about 0.4 parts by weight of fluororubber in the organic solvent 1 to form a binder solution, and then adding 0.9 parts by weight of barium titanate to the binder solution 1 in a 0.9 parts by weight.
It is dispersed. The viscosity of the ink is adjusted to be suitable for screen printing.

Next, a back electrode 58 made of a conductive paste containing silver or carbon is formed on the reflective insulating layer 57 to a thickness of 10 to 20 μm by screen printing.

Next, a melamine resin,
A protective layer 59 made of an insulating resin such as a phenol resin or an epoxy resin is formed to a predetermined thickness by screen printing, and the electroluminescent lamp 51 is obtained.

In order to turn on the electroluminescent lamp, an IC inverter for converting a low DC voltage of a battery or the like into an AC voltage is usually used.
A driving device such as a motor is used. This type of inverter includes a DC power supply, an inductor (choke, transformer, etc.), and a switching element. In operation, first, a switch is turned on, a current flows from a power supply to an inductor to store energy in the inductor, and then, the switch is turned off to release the energy to charge a capacitive load of the electroluminescent lamp. Thereafter, the terminal voltage of the electroluminescent lamp is increased by repeating on / off (step-up method). When the voltage becomes sufficiently high, the electric charge of the electroluminescent lamp is discharged. Light is emitted by repeating charge and discharge.

[0008]

When an electroluminescent lamp is lit by a conventional step-up type IC inverter, in order to improve the brightness of the electroluminescent lamp, the output voltage of the IC inverter (electroluminescence) is increased. It is effective to increase the input voltage, increase the on-time of the switch, shorten the off-time of the switch, and reduce the size of the inductor. Yes,
For an electroluminescent lamp, it has been effective to reduce the DC resistance and the overall capacitance. In particular, in order to reduce the capacitance of the electroluminescent lamp, the emission layer was formed thicker, and the relative dielectric constant of the binder was reduced, but the relative dielectric constant of the binder disposed above and below the phosphor was made. As a result, the voltage applied to the phosphor decreases,
The average electric field of the phosphor was reduced, and the luminance was not sufficiently improved.

In view of the above, the present invention has been made in view of the above-mentioned problems, and has a structure in which a resin having a small relative dielectric constant is provided between phosphors to reduce the capacitance of the light emitting layer. An object of the present invention is to provide an electroluminescent lamp in which the load at the time of driving an IC inverter is reduced, the output voltage of the IC inverter is increased, and the increased output voltage is effectively applied to a phosphor to improve the luminance, and a method of manufacturing the same. I do.

[0010]

An electroluminescent lamp according to the present invention comprises:
At least a light-emitting layer is formed between the transparent electrode and the back electrode, and the light-emitting layer includes a phosphor, a binder, and a resin layer having a relative dielectric constant smaller than that of the binder. It is characterized by being disposed by being melted and solidified between itself and the body. With this configuration, a resin layer having a small relative dielectric constant is formed between the phosphors at a high density, so that the capacitance of the light emitting layer is reduced, and the load at the time of driving the IC inverter is reduced. The output voltage of the inverter increases,
The average electric field of the phosphor is enhanced and the luminance is improved.

Further, the electroluminescent lamp of the present invention is characterized in that the weight ratio of the resin layer to the phosphor is 0.07 to 0.27. With this configuration, an appropriate amount of resin layer can be formed between the phosphors, and the luminance can be improved by driving the IC inverter.

Further, in the electroluminescent lamp according to the present invention, the resin layer is made of a resin selected from polyethylene, ethylene / acrylic acid copolymer, polypropylene and polystyrene. Since these resins have a lower dielectric constant and a lower melting point than the binder, they can be melted and solidified by low-temperature heating without adversely affecting the light emitting layer, and a desired resin layer can be formed.

[0013] The method for manufacturing an electroluminescent lamp according to the present invention comprises:
In a method of manufacturing an electroluminescent lamp in which at least a light emitting layer is formed between a transparent electrode and a back electrode, a light emitting layer is formed by using an ink in which a phosphor and a resin powder having a relative dielectric constant smaller than that of the binder are dispersed in the binder. , A step of heating the light emitting layer to melt the resin powder, and a step of solidifying the melted resin. With this configuration, an electroluminescent lamp in which a resin layer is disposed between phosphors can be easily manufactured. In this electroluminescent lamp, since a high-density resin layer having a small relative dielectric constant is formed between phosphors, the capacitance of the light-emitting layer is reduced, and the load when driving the IC inverter is reduced. As a result, the output voltage of the IC inverter increases, the average electric field of the phosphor increases, and the luminance improves.

The ratio of the average particle size of the resin powder to the average particle size of the phosphor is 0.2 to 1.1. With this configuration, the resin layer can be appropriately disposed between the phosphors, and a high-luminance electroluminescent lamp can be obtained.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electroluminescent lamp 1 according to the present invention has at least a light emitting layer 8 formed between a transparent electrode 3 and a back electrode 10 as shown in a sectional view of a main part of FIG. Is composed of a phosphor 4, a binder 5, and a resin layer 7 having a relative dielectric constant smaller than that of the binder 5, and the resin layer 7 is disposed between the phosphors 4 and 4 by being melted and solidified. It is characterized by being. A reflective insulating layer 9 may be printed on the light emitting layer 8. A protective layer 11 may be formed on the back electrode 10. FIG. 1 shows a laminated structure, and the illustration of the lead connection structure is omitted. The most important characteristic required for the resin layer 7 is the relative dielectric constant, which is sufficiently lower than that of the binder 5. Further, it is desirable that it is smaller than the phosphor 4. For example, since the relative dielectric constant of fluororubber is (about 15), the relative dielectric constant of the resin layer 7 is preferably 5 or less, and more preferably 3 or less. It is important that such a resin layer 7 is provided between the phosphors 4 (horizontal direction) disposed on the transparent electrode surface at a slight interval in the horizontal direction on the surface. If they are arranged in a direction perpendicular to the surface, that is, above and below the phosphor 4, the direction of the electric field applied to the phosphor 4 is coincident with the direction of the electric field.

The method for arranging the resin layer 7 between the phosphors 4 is most suitable for printing in consideration of mass productivity. At that time, the form of the resin used in the ink for the light emitting layer,
It is necessary to optimize the particle size, the weight ratio to the phosphor, and the like. A desirable form is a transparent resin powder of a true sphere or a shape close to this (a polyhedron or the like), and spherical transparent resin beads are preferable. The transparent resin powder includes not only a transparent resin regardless of the presence or absence of heating but also a resin which is opaque before heating but becomes transparent after heating and melting. Also, white resin powder can be used.

The particle size of the resin powder is preferably smaller than the particle size of the phosphor. Specifically, a resin powder having an average particle size of 0.2 to 1.1 times the average particle size of the phosphor is desirable. In particular, approximately 0.5 (0.4 to 0.7) times is optimal. If the particle size is excessively smaller than the phosphor particle size, it will adhere to the upper and lower surfaces of the phosphor, causing a voltage loss and lowering the luminance. Also,
Difficult to integrate by heating and melting. On the other hand, when the particle size is larger than that of the phosphor, the spacing between the phosphors in the light emitting layer after printing increases, the phosphor arrangement density decreases, and the luminance decreases.

The weight ratio of the resin layer to the phosphor is 0.0
It is preferably from 7 to 0.27. If it is smaller than 0.07, the absolute amount of the resin layer is insufficient, and the effect of reducing the capacitance of the light emitting layer cannot be sufficiently obtained. On the other hand, if it is larger than 0.27, the resin becomes excessive and is formed above and below the phosphor, so that the electric field intensity decreases and the luminance decreases. Further, the volume of the resin layer increases, the phosphor spacing increases, the phosphor array density decreases, and the luminance decreases. The above weight ratio is most suitable for a zinc sulfide phosphor (specific gravity 4.1) and a resin (specific material such as polyethylene) having a specific gravity of about 0.9. It can be applied to materials having specific gravities close to these. When the specific gravities are significantly different, it is necessary to correct the weight ratio with the specific gravities with emphasis on the volume.

It is desirable that a binder be as little as possible between the phosphors and that the resin layer be overwhelmingly. Therefore, it is desirable that the resin layer be as dense as possible. In order to form such a resin layer, the light emitting layer is heated to melt only the resin powder and solidify. A plurality of resin powders are melted and integrated to form a high-density resin layer. During heating, a resin that melts at a temperature as low as possible is desirable in order to avoid adverse effects on other layers, films, and the like. The heating temperature is desirably about 180 ° C. or less, and the melting point of the resin powder is desirably about 160 ° C. or less.

The preferred resin may be any resin as long as it has a smaller relative dielectric constant, a lower melting point, and a lower visible light absorptivity than the binder. For example, polyethylene, ethylene-acrylic acid copolymer, polypropylene,
Polystyrene and the like are preferred. These resins have a relative dielectric constant of 5 or less, are smaller than the binder, and have a melting point of 160 ° C.
Since it is as low as below, it can be melted and solidified by heating at a low temperature to form a resin layer having a small relative dielectric constant.

Next, a method of manufacturing the electroluminescent lamp 1 according to the present invention will be described with reference to the cross-sectional view of the main part of FIG. First, FIG. 2A shows a transparent conductive film having a thickness of 10 mm.
A transparent electrode 3 of ITO or the like having a thickness of about 30 to 50 nm is formed on one surface of an insulating transparent film 2 made of PET or the like having a thickness of 0 to 200 μm by vapor deposition, sputtering, or the like. Also, a transparent electrode 3 may be formed by printing a conductive paste containing a conductive powder such as ITO on one surface of the transparent film 2.

Next, FIG. 2B is a view for explaining a light emitting layer forming step. Phosphor 4 with zinc sulfide activated by copper
(A central particle diameter (median diameter) of 20 μm), a binder 5 made of fluoro rubber (specific gravity of about 1.8), and resin beads 6 unique to the present invention (for example, polyethylene beads having a relative dielectric constant of 2 to 3; Name "Flow beads" (Sumitomo Seika Co., Ltd.)
The light emitting layer 8 is formed in a thickness of 20 to 50 μm on the transparent electrode 3 by screen printing using an ink for a light emitting layer in which the light emitting layer 8 is dispersed in an organic solvent (for example, isophorone). The binder 5 is made of a fluorine rubber (for example, G501 manufactured by Daikin Industries, Ltd.) having excellent moisture proof properties in order to prevent the phosphor from being deteriorated by moisture. The method for preparing the ink for the light emitting layer is as follows.
Is dissolved in a binder solution, and then a phosphor having a weight ratio of 1.1 to 1.5 is dispersed in the binder solution 1, and a transparent material having a predetermined weight ratio with respect to the binder solution is further dispersed. The resin beads 6 are dispersed. The viscosity of the ink is adjusted to be suitable for screen printing. Also, in order to prevent the voltage applied to the phosphor 4 from decreasing, the binder 5 is not so thickly attached to the upper and lower surfaces of the phosphor 4 that
It is desirable to select the amount of binder.

In the light emitting layer 8 after printing, as shown in FIG. 2B, the phosphors 4 are arranged at a small interval, and the phosphors 4 are arranged between the phosphors 4 (in the horizontal direction). One or more resin beads 6 having a smaller particle diameter than the body are arranged, and the gap is occupied by the binder 5. By selecting the average particle size of the resin, the weight ratio with the phosphor, etc.,
The light emitting layer after printing has such a form on average. In particular, if the resin beads 6 having a small relative dielectric constant adhere to the upper surface or the lower surface of the phosphor 4, the voltage applied to the phosphor 4 decreases, which causes a decrease in luminance.

Next, FIG. 2C is a view for explaining a light emitting layer heating step peculiar to the present invention. In this step, the transparent conductive film after printing the light emitting layer shown in FIG.
It is placed in an electric oven and heated to melt the resin beads 6. One or a plurality of resin beads 6 between the phosphors are melted and integrated, and are densely filled between the phosphors 4 to form a resin layer 7, as shown in FIG. Form. It is most preferable that the resin having a small relative dielectric constant is filled between the phosphors. The temperature and time are selected so that only the resin beads are melted.
For example, in the case of polyethylene beads,
C. and about 10 to 30 minutes are suitable.

Next, the heating is stopped and the resin layer 7 is solidified by natural cooling.

Next, the reflective insulating layer 9, the back electrode 10, and the protective layer 11 are formed on the light emitting layer after the resin layer is solidified in the same manner as in the conventional case, and the electroluminescent lamp 1 is obtained.

Now, in the above-described electroluminescent lamp 1, the phosphor 4
Since the resin layer 7 having a smaller relative dielectric constant (and thus a smaller capacitance) than the phosphor 4 and the binder 5 is formed between the phosphor layer 4 and the binder 4, the average capacitance of the light emitting layer 8 is reduced. descend. For this reason, when the electroluminescent lamp 1 is lit by a conventional IC converter, the output voltage of the IC inverter increases by an amount corresponding to the reduction in the capacitance and the reduction in the load. Therefore, the average voltage applied to the light emitting layer 8 increases, and the phosphor 4
As the electric field increases, the luminance is improved.

[0028]

EXAMPLES (Example 1) Fluororubber in a weight ratio of 0.4 was dissolved in an organic solvent (isophorone) 1 to form a binder solution, and then 1.4 in a weight ratio with respect to the binder solution 1. Of zinc sulfide phosphor (average particle size: 23 μm) was dispersed, and the weight ratio was 0.15 with respect to the binder solution 1.
Polyethylene beads (Product name "Flow beads HE-304
0 ", relative permittivity 2-3, average particle size 12 in weight distribution
The light emitting layer 8 is dispersed in a thickness of 30 to 50 μm by screen printing on the transparent electrode 3 using the light emitting layer ink in which
Formed to a thickness of Then heated at 150 ° C. for 30 minutes,
Allow to cool naturally. Next, the reflective insulating layer 9, the back surface electrode 10 and the like are laminated and formed in the same manner as in the related art to obtain the electroluminescent lamp 1.

Example 2 The above polyethylene beads (HE-304) in a weight ratio of 0.20 to the binder solution 1 were used.
An electroluminescent lamp is obtained in the same manner as in Example 1 except that (0) is dispersed.

Example 3 The above polyethylene beads (HE-304) in a weight ratio of 0.25 to the binder solution 1 were used.
An electroluminescent lamp is obtained in the same manner as in Example 1 except that (0) is dispersed.

(Example 4) A phosphor having a weight ratio of 1.3 was dispersed in the binder solution 1, and the polyethylene beads (HE-3040) having a weight ratio of 0.15 with respect to the binder solution 1 were further dispersed. An electroluminescent lamp is obtained in the same manner as in Example 1 except that

Example 5 A phosphor having a weight ratio of 1.3 was dispersed with respect to the binder solution 1, and the polyethylene beads (HE-3040) having a weight ratio of 0.20 with respect to the binder solution 1 were further dispersed. ) Is obtained in the same manner as in Example 1 except that the electroluminescent lamp is dispersed.

Example 6 A phosphor having a weight ratio of 1.3 was dispersed with respect to the binder solution 1, and the polyethylene beads (HE-3040) having a weight ratio of 0.25 with respect to the binder solution 1 were further dispersed. ) Is obtained in the same manner as in Example 1 except that the electroluminescent lamp is dispersed.

(Example 7) 1.5 weight parts of phosphor were dispersed in the binder solution 1 and 0.15 weight parts of the above-mentioned polyethylene beads (HE-3040) were added to the binder solution 1. An electroluminescent lamp is obtained in the same manner as in Example 1 except that

Example 8 1.5 phosphors were dispersed in a weight ratio of 1.5 to the binder solution 1, and the polyethylene beads (HE-3040) in a weight ratio of 0.20 to the binder solution 1 were further dispersed. ) Is obtained in the same manner as in Example 1 except that the electroluminescent lamp is dispersed.

(Example 9) 1.5 parts by weight of the phosphor was dispersed in the binder solution 1 and 0.25 parts by weight of the above-mentioned polyethylene beads (HE-3040) with respect to the binder solution 1. ) Is obtained in the same manner as in Example 1 except that the electroluminescent lamp is dispersed.

Example 10 A phosphor having a weight ratio of 1.4 was dispersed in the binder solution 1 and polyethylene beads having a weight ratio of 0.10 with respect to the binder solution 1 (trade name “Flow Beads”). LE-1080 '', relative permittivity 2
3. Average particle size in the weight distribution 6 μm, melting point 107 ° C.)
The light-emitting layer 8 is formed in a thickness of 30 to 50 μm by screen printing on the transparent electrode 3 using the light-emitting layer ink in which is dispersed, and then heated at 130 ° C. in the same manner as in Example 1 to obtain an electric field. Obtain a luminous lamp.

(Example 11) A phosphor having a weight ratio of 1.4 was dispersed with respect to the binder solution 1, and the polyethylene beads (LE-1080) having a weight ratio of 0.20 with respect to the binder solution 1 were further dispersed. An electroluminescent lamp was obtained in the same manner as in Example 10 except that

Example 12 A phosphor having a weight ratio of 1.1 was dispersed in the binder solution 1 and polyethylene beads having a weight ratio of 0.30 with respect to the binder solution 1 (trade name “Flow beads”). LE-9020 '', relative dielectric constant 2
3. Using a light emitting layer ink in which an average particle diameter of 25 μm and a melting point of 107 ° C. are dispersed, a light emitting layer 8 is formed to a thickness of 30 to 50 μm on the transparent electrode 3 by screen printing, and then heated at 130 ° C. Except for the above, an electroluminescent lamp is obtained in the same manner as in the first embodiment.

(Example 13) A phosphor having a weight ratio of 1.2 was dispersed in the binder solution 1, and the polyethylene beads (LE-9020) having a weight ratio of 0.20 with respect to the binder solution 1. An electroluminescent lamp was obtained in the same manner as in Example 12 except that

(Example 14) A phosphor having a weight ratio of 1.3 was dispersed with respect to the binder solution 1, and the polyethylene beads (LE-9020) having a weight ratio of 0.10 with respect to the binder solution 1 were further dispersed. An electroluminescent lamp was obtained in the same manner as in Example 12 except that

Example 15 A phosphor having a weight ratio of 1.4 was dispersed in the binder solution 1 and the polyethylene beads having a weight ratio of 0.20 with respect to the binder solution 1 (LE-9020) An electroluminescent lamp was obtained in the same manner as in Example 12 except that

Example 16 A phosphor having a weight ratio of 1.4 was dispersed in the binder solution 1 and ethylene / acrylic acid copolymer beads having a weight ratio of 0.1 with respect to the binder solution 1. (Product name "Flow beads EA-209",
Relative dielectric constant 2-3, average particle size in weight distribution 10 μm,
Melting point 105 ° C.)
The light-emitting layer 8 is screen-printed on the transparent electrode 3 by 30 to
An electroluminescent lamp is obtained in the same manner as in Example 1 except that the lamp is formed to a thickness of 50 μm and then heated at 130 ° C.

(Comparative Example 1) A luminescent layer ink in which a phosphor in a weight ratio of 1.4 was dispersed with respect to the binder solution 1 (however, resin beads were not dispersed) was used on the transparent electrode 3. The light emitting layer is 30 to 50 μm by screen printing.
(The same thickness as in the embodiment), and then a reflective insulating layer, a back electrode, and the like are laminated and formed in the same manner as in the related art to obtain an electroluminescent lamp.

(Evaluation Method and Evaluation Results) The electroluminescent lamps of Examples 1 to 16 and Comparative Example 1 were replaced with a sine wave AC power supply (40 V, 600 Hz) or an IC inverter (model SP4425,
Connect to input voltage 3.5V) and turn on. The luminance of the light emitting surface is measured with a luminance meter. The luminance of Comparative Example 1 was set to 1 for each driving method.
The luminance measured value of each example is represented by a relative value as 00, and is shown in Table 1. The relative luminance of Comparative Example 1 of each driving method is 100, but the absolute luminance is different. The brightness of the electroluminescent lamp of the present invention is improved as compared with the conventional one. In particular, I
When turned on by the C inverter, the brightness is significantly improved. The weight ratio of the resin beads to the phosphor was calculated from Table 1 (for example, 0.15 / 1.4 = 0.10 in Example 1).
7), and the relative luminance (when driving the IC inverter) with respect to this weight ratio is shown in FIG. FIG. 3 shows that although the luminance level varies depending on the average particle size of the resin beads, the weight ratio is generally equal to 0.
It can be seen that the luminance is improved over the prior art (relative luminance 100) in the range of 07 to 0.27. FIG. 4 shows the relationship between the ratio of the average particle size of the resin beads to the average particle size of the phosphor and the relative luminance (when driving the IC inverter). From FIG. 4, it can be seen that the luminance is improved as compared with the related art (relative luminance 100) when the particle size ratio is in the range of 0.2 to 1.1. In particular, a particle size ratio of about 0.5 (0.4 to 0.7) is optimal.

[0046]

[Table 1]

[0047]

The electroluminescent lamp of the present invention has a light emitting layer comprising a phosphor, a binder, and a resin layer having a relative dielectric constant smaller than that of the binder, and the resin layer comprises a phosphor and a phosphor. It is characterized by being arranged by being melted and solidified between them.
Further, the method for manufacturing an electroluminescent lamp according to the present invention includes a step of printing a light emitting layer using an ink in which a phosphor and a resin powder having a relative permittivity smaller than that of the binder are dispersed in the binder; and It is characterized by having a step of melting the resin powder by heating and a step of solidifying the molten resin. With the above configuration, the capacitance of the light emitting layer can be reduced.
Lighting by the C inverter can provide an electroluminescent lamp whose output voltage is improved and whose brightness is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part for explaining the structure of an electroluminescent lamp according to the present invention.

FIG. 2 is a cross-sectional view of a main part for describing a method of manufacturing an electroluminescent lamp according to the present invention.

FIG. 3 is a view for explaining the relationship between the weight ratio of the resin layer to the phosphor of the electroluminescent lamp of the present invention and the luminance.

FIG. 4 is a diagram for explaining the relationship between the ratio of the average particle size of the resin layer to the average particle size of the phosphor of the electroluminescent lamp of the present invention and the luminance.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electroluminescent lamp 2 Transparent film 3 Transparent electrode 4 Phosphor 5 Binder 6 Resin powder (for example, resin beads) 7 Resin layer 8 Light emitting layer 9 Reflective insulating layer 10 Back electrode 11 Protective layer

Claims (5)

[Claims] 1. An electroluminescent lamp having at least a light emitting layer formed between a transparent electrode and a back electrode, wherein the light emitting layer comprises a phosphor, a binder, and a resin layer having a relative dielectric constant smaller than that of the binder. Wherein the resin layer is disposed between the phosphors by being melted and solidified. 2. The weight ratio of the resin layer to the phosphor is 0.07.
2. The electroluminescent lamp according to claim 1, wherein the number is 0.27 to 0.27. 3. The resin layer is made of polyethylene, ethylene.
The electroluminescent lamp according to claim 1, wherein the electroluminescent lamp is made of a resin selected from an acrylic acid copolymer, polypropylene, and polystyrene. 4. A method for manufacturing an electroluminescent lamp in which at least a light emitting layer is formed between a transparent electrode and a back electrode, wherein an ink in which a phosphor and a resin powder having a relative dielectric constant smaller than that of the binder are dispersed in the binder. Printing a light emitting layer using, and heating the light emitting layer to melt the resin powder,
Solidifying the molten resin. 5. The method according to claim 4, wherein the ratio of the average particle size of the resin powder to the average particle size of the phosphor is 0.2 to 1.1.