JP3361197B2 - EL emission guidelines - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EL light emitting pointer used for instruments such as watches.

[0002]

2. Description of the Related Art A conventional EL device 16 shown in FIGS.
Forms a transparent electrode 18 made of ITO (indium tin oxide) by sputtering or the like on a transparent base film 17 made of a synthetic resin film. On the transparent electrode 18, a light emitting layer 19, an insulating layer 20, and a back surface are formed. After the electrodes 21 are sequentially laminated, the entire laminated body is covered with moisture-proof films 22a, 22 made of trifluorochloroethylene resin or the like.
The EL element 16 is completed as a single body by encapsulating the ends by thermocompression bonding or the like from above and below by b. Therefore, when a light emitting pointer used for a watch or the like is created, the EL element 16 is attached to the pointer body 23 provided with the light emitting window 23a.

[0003]

SUMMARY OF THE INVENTION In the above conventional configuration,
To attach the completed EL element 16 to the pointer body 23,
Moisture-proof films 22a, 22 located outside the light-emitting layer 19
The sealing portion 22c of b is attached to the window frame portion of the pointer body 23. This window frame part becomes a non-light emitting part, and the entire surface of the pointer cannot be made to emit light. Even if the window frame is made transparent, since the light emitting layer 19 does not exist in the sealing portion (the portion where the moisture-proof films are directly fixed to each other) 22c of the moisture-proof film, the pointer body 23 cannot emit light over the entire width.

The thickness of the moisture-proof films 22a and 22b occupies about half of the thickness of the EL element 16 as a whole, that is, the presence of the moisture-proof films 22a and 22b hinders the EL element 16 from being made thinner. There is.

Further, the normal EL element 16 has a poor three-dimensional effect because the front surface uniformly emits light, and the color (milky white) of the light emitting layer is exposed when the light is not emitted, which imposes a design constraint. In some cases, further improvement in decorativeness is desired.

It is therefore an object of the present invention to provide an EL light emitting pointer which does not require a window frame and can be used as a light emitting surface over the entire width of the pointer body, which can be made thin and which is more decorative.

[0007]

In order to achieve the above object, in the present invention, a thin film transparent electrode is formed on a pointer-shaped base plate, and a light emitting layer is further formed on the transparent electrode.
In an EL light emitting pointer in which an insulating layer and a back electrode are sequentially stacked, at least one of a fluorescent dye and a fluorescent pigment is contained as a base plate to have a light-collecting property, and at least one of the light emitting layer and the insulating layer is made of a transparent resin. that a high fluorocarbon resin with an aqueous formed as the binder, to the back electrode is formed using respective ones of the reaction accelerator to promote the polymerization reaction of the fluororesin is contained.

Further, in the above construction, a base plate having a light transmissive property may be used in place of the light collecting property. Alternatively, the transparent electrode may be formed of a metal thin film to have conductivity and light semi-transparency, thereby simplifying the configuration.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

A first embodiment of an EL light emitting pointer according to the present invention is shown in FIGS. This light emitting pointer has an EL element (electroluminescence element) 2 attached to a pointer case 1. As shown in FIG. 2, the pointer case 1 includes a hook 3 fitted to a pointer shaft of a timepiece machine body (not shown), metal sliding contact pieces 4 and 5, and an EL element mounting portion 6.
have. The sliding contact pieces 4 and 5 are arranged so as not to be electrically connected to each other, and the contacts 4a and 5a are integrally formed respectively. When the pointer is rotated, electric power can be supplied by sliding the contacts 4a and 5a on a pair of ring-shaped conductors (not shown) that are concentrically provided with the center of rotation of the pointer.

The EL element 2 shown in FIGS. 3 and 4 contains at least one of a fluorescent dye and a fluorescent pigment in a synthetic resin having translucency (acrylic, polycarbonate, vinyl chloride, polystyrene, polyethylene terephthalate, styrene acrylonitrile, etc.). Light collecting base plate 6
ITO (Indium Tin Oxide) is sputtered thereon to form the transparent electrode 7.

A luminescent ink composed of a phosphor and a fluororesin binder is printed on the transparent electrode 7 to form a luminescent layer 8.
Are formed. Specifically, in this example, copper-doped zinc sulfide (ZnS) was used as the phosphor, and a binder obtained by dissolving a copolymer of vinylidene fluoride and propylene hexafluoride in methyl ethyl ketone was used as the fluororesin binder. A binder prepared by previously dissolving 10 g of the polymer in 25 g of methyl ethyl ketone and 60 g of the phosphor are mixed and stirred to obtain a luminescent ink. This luminescent ink is printed on the ITO vapor deposition surface by a method such as screen printing, heated and dried to form the luminescent layer 8.

An insulating ink is printed on the light emitting layer 8 to form an insulating layer 9. Specifically, 35 g of a fluororesin binder similar to that used in the above-mentioned luminescent ink and 60 g of barium titanate (BaTiO ₃ ) which is a high dielectric substance.
The insulating ink produced by mixing and stirring is printed on the light emitting layer 8 and then heated and dried to form the insulating layer 9. Although the fluororesin binder has a low dielectric constant, barium titanate has a very high dielectric constant (180 [f / M]), so that a high dielectric constant can be ensured for the entire insulating layer, and the emission brightness of the EL element is reduced. There is no invitation.

A back electrode 10 is formed on the insulating layer 9. This back electrode 10 is made of conductive carbon powder 80 g.
And a resin binder in which 10 g of polyester resin is dissolved in 90 g of solvent isophorone are mixed and stirred, and a carbon ink to which a reaction accelerator is added is printed on the insulating layer 9 and heated and mixed. . The reaction accelerator accelerates the polymerization reaction of the fluororesin binder in the light emitting layer 8 and the insulating layer 9, and one example thereof is an organosilicon monomer N-β having two or more different reactive groups in the molecule.
(Aminoethyl) γ-aminopropyltrimethoxysilane H ₂ NC ₂ H ₄ NHC ₃ H ₆ Si (OCH ₃ ) ₃ is used.

Lead-out portions 7a and 10a are provided from the transparent electrode 7 and the back electrode 10, respectively.

The EL element 2 manufactured in this way is
The lead-out portions 7a and 10a are inserted into the EL element mounting portion 6 of the pointer case 1 and connected to the sliding contact pieces 4 and 5 via the leads 11a and 11b to be integrated. The EL element 2 itself has a pointer shape and is driven by a timepiece mechanical body (not shown) to rotate to display the time, and the sliding contact pieces 4, 5, the leads 11a, 11b, and the lead portion 7a are supplied from an external power source (not shown). , 10a, an electric field is applied to the transparent electrode 7 and the back electrode 10 to cause the light emitting layer 8 to emit light.

In the EL element 2 having the above-mentioned structure, the light emitting layer 8 and the insulating layer 9 are mixed with fluororesin, and the back electrode 1 is used.
Since the reaction accelerator is mixed into the phosphor, there is no possibility that water will enter the phosphor of the light emitting layer and deteriorate. Explaining this, the fluororesin has a water absorption of 0.04.
% (Value indicating the ratio of water content as a weight ratio: 100
It shows that 0.04 g of water can be impregnated into g of fluororesin. ), Which is much lower than that of cyanoethylated cellulose (water absorption rate 2%) used as a binder in conventional light emitting layers and insulating layers of EL devices. Furthermore, the reaction accelerator added to the carbon ink forming the back electrode 10 permeates into the insulating layer 9 and the light emitting layer 8 during heating and drying, so that the fluororesins in the insulating layer 9 and the light emitting layer 8 are separated from each other. It accelerates the polymerization reaction, increases the density of the fluororesin and prevents the ingress of water. As described above, according to the present invention, since the phosphor of the light emitting layer is not deteriorated by moisture, the conventionally used moisture-proof film becomes unnecessary. Therefore, the EL element can be made thin, and since the moisture-proof film has no sealing portion, the width can be reduced and the entire width of the pointer can be used as the light emitting surface.

In this example, the reaction promoter was 2
Since an organosilicon monomer having at least one kind of reactive group is used, one of the reactive groups reacts with the fluorescent substance which is an inorganic substance, and the other reactive group reacts with the fluororesin which is an organic substance to thereby form a fluorescent substance. It is wrapped with a fluororesin, and has the function of blocking moisture from entering the phosphor by being blocked by the fluororesin layer. The same applies to the case of the insulating layer, and the high dielectric is wrapped with the fluororesin layer so that moisture is blocked by the fluororesin layer and cannot enter the high dielectric. Therefore, the moisture resistance is further improved.

In the present invention, since the base plate 6 containing a fluorescent dye or a fluorescent pigment and having a light-collecting property is used, the light emitted from the side surface of the base plate is better than the light emitted from the front surface (light emitting surface) of the pointer. There are many, and it is possible to emit light with a rich stereoscopic effect.

This EL light emitting pointer is used at 40 ° C. × 90% RH
When light emission was driven for 200 hours under a driving condition of 100 V × 400 Hz in an environment of (relative humidity), the emission luminance maintaining characteristic shown in FIG. 5 and the loss coefficient tan δ (one of the electrical characteristics of the EL element) shown in FIG. ) And was obtained.

As described above, the addition of the reaction accelerator improves the luminance maintaining characteristic in all regions as compared with the case where the reaction accelerator is not added. It is substantially effective if the amount of the reaction accelerator added to the back electrode is 2 wt% or more, but particularly when the amount of the reaction accelerator added is in the range of 5 to 14 wt%, the brightness maintaining characteristics are high and effective. is there. Further, the loss coefficient becomes smaller as the amount of the reaction accelerator added to the back electrode becomes larger. The small loss coefficient indicates that the moisture absorption is small and the moisture-proof effect is high. In addition, as shown in the following table, the addition amount of the reaction accelerator does not significantly affect the emission luminance.

[0022]

[Table 1]

A method of adding a vulcanizing agent typified by peroxide as a reaction agent of vinylidene fluoride and propylene hexafluoride when forming the light emitting layer and the insulating layer and vulcanizing is also conceivable. When the resin is subjected to a vulcanization reaction, the moisture resistance is slightly improved, but the moisture resistance to the extent that the moisture-proof film is unnecessary is not expected, and there is a fatal problem that the emission luminance of the EL element is reduced by half by vulcanization. Also,
When a reaction accelerator is added to luminescent ink or insulating ink,
Even at room temperature, the polymerization reaction of the fluororesin proceeds at the same time when the reaction accelerator is added, and the ink solidifies in a short time, making it virtually impossible to form it by printing.
Therefore, the method of the present invention in which the reaction promoter is added to the back electrode is most effective.

The fluororesin binder to be mixed in the light emitting layer 8 and the insulating layer 9 is not limited to the above examples, but polyvinylidene fluoride as a polymer of vinylidene fluoride or vinylidene fluoride and another fluororesin such as ethylene fluoride ethylene. It is also possible to use at least one copolymerizable copolymer of vinyl fluoride, ethylene trifluoride, ethylene trifluoride chloride, tetrafluoroethylene, and hexafluoropropylene.
Further, although zinc sulfide doped with copper was used as the phosphor,
This phosphor may be coated with a transparent inorganic dielectric material such as SiO ₂ , TiO ₂ , and Al ₂ O ₂ in advance.

As the reaction accelerator, in addition to the above examples, γ-glycidoxypropyltrimethoxysilane, which is an organosilicon monomer having two or more different reactive groups in the molecule, is used.

[0026]

[Chemical 1]

Although not an organosilicon monomer, anhydrotrimeritate

[0028]

[Chemical 2]

And the like are used.

Next, another embodiment of the present invention will be described below.

In a normal EL light emitting guide, the color (milky white) of the light emitting layer itself is exposed when the light is not emitted, and thus the decorativeness when the light is not emitted is difficult. When the base plate contains a fluorescent dye or fluorescent pigment in the same manner as in the above-mentioned examples, a mixed color of the color of the dye or pigment and the milky white of the light emitting layer is exhibited at the time of non-emission, but the same tone as that at the time of emission There is a case where the color is different from the above, which may not be enough as a decorative effect.

Therefore, the base plate is made to be semi-transmissive. That is, in the second embodiment shown in FIG. 7, metal powder such as gold or aluminum was mixed into the outer surface (the surface opposite to the transparent electrode formation surface) of the synthetic resin plate similar to the first embodiment. A base plate 12 having a so-called half-mirror effect is formed by printing a paint 12a, and when the EL element does not emit light, it has a metallic luster of gold or silver and is mirror-like.
It shines with the emission color of the element. The components other than the base plate 12 (the transparent electrode 7, the light emitting layer 8, the insulating layer 9, the back electrode 10 and the pointer case 1) have the same configurations as those in the first embodiment, and the same reference numerals are given and the description thereof is omitted. To do.

In the third embodiment shown in FIG. 8, a metal powder of gold or aluminum is mixed into a synthetic resin so that the base plate 13 itself has a light semi-transmissive property. According to this, similarly to the above, it has a half-mirror effect that emits a metallic luster at the time of non-emission and shines an EL emission color at the time of emission, and a paint printing step is unnecessary.

In the fourth embodiment shown in FIG. 9, a base plate 15 is used in which a metal thin film 14 such as gold or aluminum is coated on a synthetic resin plate to a thickness of 0.05 μm or less. Also by this, the half mirror effect is obtained and the decorative property is improved. In this case, the metal thin film 14 is formed on the surface on the side of the light emitting layer and also has a function as a transparent electrode, so that the structure can be simplified.

In any of these second to fourth embodiments, the aesthetics of the pointer when not emitting light can be enhanced, and the difference between when not emitting light and when emitting light can be increased to give an unexpected effect, so that the decorative effect is extremely high. Can be increased to

[0036]

As described above, in the EL device of the present invention, the fluororesin is mixed into at least one of the light emitting layer and the insulating layer, and the reaction accelerator which promotes the polymerization reaction of the fluororesin is mixed into the back electrode. Therefore, the amount of infiltration of water can be reduced and deterioration of the phosphor of the light emitting layer due to water can be prevented. Therefore, it is not necessary to sandwich it with a moisture-proof film as in the conventional case, the EL element can be thinned and narrowed, and the entire width of the pointer can be used as the light emitting surface.

When a base plate containing a fluorescent dye or a fluorescent pigment and having a light-collecting property is used, the light emitted from the side surface of the base plate is larger than the light emitted from the front surface (light emitting surface) of the pointer, and the stereoscopic effect is obtained. It can emit abundant light.

When the base plate is made to be semi-transmissive, it has a mirror-like shape with a metallic luster of gold or silver when not emitting light, and when emitting light, a half mirror effect that shines with the emission color of the EL element is exhibited. The decorative effect is greatly improved because the aesthetics of the pointer when not emitting light is enhanced and the difference between when emitting light and when emitting light is large and surprising. In particular, in the case where the synthetic resin plate is provided with a metal thin film so as to have a light semi-transmissive property, the structure can be simplified by having a function as a transparent electrode.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment of an EL light emitting pointer according to the present invention.

2A is a front view of the first embodiment, and FIG. 2B is a rear view thereof.

FIG. 3A is a front view of an EL device of the first embodiment,
(B) Rear view

FIG. 4 is an enlarged sectional view of the first embodiment.

FIG. 5 is a luminance maintaining characteristic diagram of the first embodiment.

FIG. 6 is a loss coefficient characteristic diagram of the first embodiment.

FIG. 7 is an enlarged sectional view of the second embodiment.

FIG. 8 is an enlarged sectional view of the third embodiment.

FIG. 9 is an enlarged cross-sectional view of the fourth embodiment.

FIG. 10A is a front view of a conventional EL light emitting pointer,
(B) Rear view

FIG. 11 is an enlarged sectional view of a conventional EL light emitting pointer.

[Simple explanation of symbols]

2 EL element 6 base plate 7 Transparent electrode 8 Light emitting layer 9 Insulation layer 10 Back electrode 12 base plate 13 Base plate 14 Metal thin film (transparent electrode) 15 Base plate

Front page continued (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01D 11/28 G01D 13/02 G01D 13/28 G04B 19/30-19/32

Claims (3)

(57) [Claims] 1. A thin film-shaped transparent electrode is formed on a pointer-shaped base plate, and a light-emitting layer, an insulating layer, and a back electrode are sequentially laminated on the transparent electrode, wherein the base plate is a fluorescent dye. Alternatively, at least one of the fluorescent pigments is contained and has a light-collecting property, and at least one of the light emitting layer and the insulating layer is formed by using a highly water-repellent fluororesin as a binder, and the back electrode has the above-mentioned material. EL emission guidelines, characterized in that the reaction accelerator to promote the polymerization reaction of the fluorine resin is contained. 2. A thin-film transparent electrode is formed on a pointer-shaped base plate, and a light emitting layer, an insulating layer, and a back electrode are sequentially laminated on the transparent electrode. At least one of the light emitting layer and the insulating layer is formed using a highly water-repellent fluororesin as a binder, and the back electrode contains a reaction accelerator that accelerates the polymerization reaction of the fluororesin. EL emission guidelines, characterized in that it is. 3. A thin-film transparent electrode is formed on a pointer-shaped base plate, and a light-emitting layer, an insulating layer, and a back electrode are sequentially laminated on the transparent electrode. At least one of the light emitting layer and the insulating layer is formed using a highly water-repellent fluororesin as a binder, and the back electrode contains a reaction accelerator that accelerates the polymerization reaction of the fluororesin. EL emission guidelines, characterized in that it is.