JPH05242969A - Electroluminescence lamp - Google Patents

Abstract

PURPOSE:To reduce the shade of current collecting belts on a luminescence face to the extent possible and provide nearly uniform luminescence intensity on the excitation side and the nonexcitation side of an electroluminescence element. CONSTITUTION:In an electroluminescence element 1 having a laminated structure of a back electrode 6, a reflecting/insulating layer, a luminescence layer 8, and a transparent electrode 9, a pair of current collecting bands 20A, 20B are arranged face to face on the lead guide side end section and the opposite side end section of the transparent electrode 9. Both current collecting belts 20A, 20B are electrically connected by a conducting member 23 arranged around the back electrode 6 side via auxiliary current collecting members 22A, 22B.

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 more particularly to an organic electroluminescent lamp used as a backlight of a liquid crystal display device.

[0002]

2. Description of the Related Art An organic electroluminescent lamp used for a backlight of a liquid crystal display device is, for example, an electroluminescent element composed of a laminate described later having a substantially rectangular plane shape as shown in FIGS. (1), lead of phosphor bronze, etc. (2) (3)
In a state in which the above is led out, a flexible outer film (4) (5) having a moisture-proof property such as a fluororesin is sandwiched between the upper and lower parts to hermetically seal.

The electroluminescent device (1) comprises a back electrode (6) made of aluminum foil or the like in order from the bottom layer, a reflective insulating layer (7) in which barium titanate or the like is dispersed and carried on an organic binder, and copper on the organic binder. A laminate of a light-emitting layer (8) in which an activated zinc sulfide phosphor is dispersed and carried, a transparent electrode (9) such as ITO, and a transparent plastic sheet (10) as a base material of the transparent electrode (9). Is. Then, on the back electrode side at the periphery of the transparent electrode (9), an Ag paste or carbon electrically connected to the lead (3) for the purpose of ensuring a substantially uniform light emitting property over the entire surface of the electroluminescent lamp. A current collecting band (12) made of a conductive material such as the above is formed in a U shape, an I shape, or an L shape. Also, transparent electrodes (9)
An insulating film (13) may be applied so as to cover the current collecting band (12) extending along the peripheral edge of the transparent electrode (9) in order to ensure a withstand voltage between the back electrode (6) and the back electrode (6). .. Incidentally, (14)
(15) is a hygroscopic film such as nylon disposed above and below the electroluminescent element (1).

[0004]

In the conventional electroluminescent lamp, as shown in FIG. 4, the current collecting band (12) formed on the transparent electrode (9) is on the surface side of the electroluminescent element (1), that is, , Located above the light emitting layer (8). Therefore, when an AC voltage is applied via the leads (2) and (3) to cause the electroluminescent element (1) to emit light, the current collecting band (12) arranged on a part of the light emitting surface becomes a shadow. As a result, it becomes a non-light emitting region and the light emitting area is reduced. In addition, in recent large-sized electroluminescent lamps,
In the case of an I-shaped current collecting band, the voltage drop at the opposite end of the leads (2) and (3) is particularly large with respect to the lead-out side of the leads (2) and (3), and However, there was a problem that the opposite end (B) was darkened, and it was difficult to obtain a uniform light emitting surface. Therefore, if the current collecting band is formed in a U shape as shown in FIG. 5, the voltage drop is reduced and the luminance distribution is improved, but on the other hand, there is a problem that the area of the current collecting band is increased and the light emitting area is decreased.

[0005]

As a means for solving the above problems, the present invention provides an electroluminescent device in which a back electrode, a reflective insulating layer, a light emitting layer and a transparent electrode are laminated, and a current collecting band is formed on the transparent electrode. In the case where the leads are led out from the current collecting band of the back electrode and the transparent electrode and sealed with an outer cover film from above and below, a pair of lead lead-out side end and the opposite side end of the transparent electrode are provided. The present invention is characterized in that the current collecting bands are arranged so as to face each other, and both the current collecting bands are electrically connected to each other by a conductive member arranged around the back electrode.

The following structure is preferable for the above-mentioned current collector band drawing structure.

First, an auxiliary current collecting member is formed on the upper surface of the transparent electrode, and the auxiliary current collecting member and the current collecting band formed on the lower surface of the transparent electrode are electrically connected through a through hole, The auxiliary current collecting member is connected to the end of the conductive member.

Secondly, the film-shaped auxiliary current collecting member is extended from the current collecting band formed on the lower surface of the transparent electrode to the upper surface of the transparent electrode, bypassing the peripheral portion of the transparent electrode, and the extending end portion thereof is made into a conductive member. Connect with the end of.

Thirdly, an auxiliary current collecting member is formed on the upper surface of the transparent electrode, the end of the auxiliary current collecting member is led out to the outside of the outer film, and the leading end is connected to the end of the conductive member.

[0010]

According to the present invention, a pair of current collecting bands are arranged opposite to each other on the lead-out side end and the opposite side end of the transparent electrode, and both current collecting bands are electrically connected by a conductive member arranged around the back electrode. By making a positive connection, the non-light emitting area on the light emitting surface can be reduced as much as possible, and the voltage drop at the end portion on the opposite side to the lead lead-out end portion can be suppressed as much as possible. Ensure a uniform light emission state.

[0011]

Embodiments of the present invention will be described below with reference to FIGS. In the description below, the same components as those in FIGS. 4 and 5 are denoted by the same reference numerals, and the description of the overlapping matters will be omitted.

In the first embodiment shown in FIGS. 1 and 2A, a back electrode (6), a reflective insulating layer (7), a light emitting layer (8) and a transparent electrode (9) are laminated to form a transparent film. An electroluminescent element (1) is formed by disposing two current collecting bands (20A) and (20B) facing each other on the electrode (9), and the current collecting provided on the transparent electrode (9) side. The electroluminescent element (1) is arranged above and below the moisture absorbing film (14) with one lead (3) led out from the strip (20A) and the other lead (2) led out from the back electrode (6) side. ) (15) is interposed and the outer film (4) (5) is attached and sealed to form an electroluminescent lamp. The illustration of the moisture absorption film (15) is omitted.

As described above, the lead-out side end of the transparent electrode (9) and the current collecting band (20
A) and (20B) are electrically connected by a conductive member (23) arranged around the back electrode (6).

Specifically, the above-mentioned current collecting band routing structure (12
A) and (12B) are transparent electrodes (9) as shown in FIG. 2 (A).
Auxiliary current collecting members (22A) (22B) are formed on the upper surface of the auxiliary current collecting members (22A) (22B) and the current collecting bands (20A) (20B) formed on the lower surface of the transparent electrode (9). Are electrically connected to each other via through holes (21) (21) made of copper foil or the like. Auxiliary current collector (22A) (22
B) is connected to the end of the conductive member (23) arranged in a drawn manner, whereby the current collecting bands (20A) (20B) are electrically connected on the back electrode (6) side.

In the second embodiment shown in FIGS. 1 and 2B, the details of the current collecting band routing structures (12A) and (12B) are different from those shown in FIG. 2A. Has the same structure as that of the first embodiment. The current collecting band routing structure (12A) (12B) in the second embodiment is a film-like structure formed by coating a conductive paste such as Ag on the surface or vapor-depositing a conductive metal thin film. It is formed from the auxiliary current collecting members (22A) and (22B).

The film-shaped auxiliary current collecting member (22A) (2
2B) current collector band (20A) formed on the lower surface of the transparent electrode (9)
The current collecting band (20B) is formed by circumscribing the peripheral portion of the transparent electrode (9) from (20B) and extending it to the upper surface, and connecting the extending end to the end of the conductive member (23) arranged.
A) and (20B) are electrically connected on the back electrode (6) side.

Further, the current collecting band routing structure (12A) (12B) in the third embodiment shown in FIG. 3 has a transparent electrode (9).
Auxiliary current collecting members (22A) (22B) similar to those shown in FIG. 2 (A) or (B) are formed on the upper surface of the, and the ends thereof are led out to the outside of the outer film (4) (5), By connecting the lead-out end to the end of the conductive member (23) arranged around, the current collecting bands (20A) (20B) are electrically connected on the back electrode (6) side. In this case, the electroluminescent device (1)
The current collectors (20A) and (20B) will be connected outside the.

[0018]

According to the present invention, the increase of the non-light emitting area due to the generation of the shadow of the current collecting band on the light emitting surface is avoided, and the voltage is provided on the non-power feeding side opposite to the power feeding side having the lead. Since a decrease in light emission brightness due to the drop is avoided, a uniform light emitting state can be obtained on the light emitting surface, and a high quality electroluminescent lamp can be provided.

[Brief description of drawings]

FIG. 1 is a plan view of an electroluminescent lamp according to the present invention.

FIG. 2A is a sectional view showing a first embodiment of the present invention,
FIG. 3B is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a plan view showing a third embodiment of the present invention.

4A is a cross-sectional view of a conventional electroluminescent lamp, and FIG. 4B is a plan view of the conventional electroluminescent lamp.

FIG. 5 is a plan view illustrating a current collecting band provided in a conventional electroluminescent lamp.

[Explanation of symbols]

 1 Electroluminescent device 2, 3 Lead 4 Skin film 6 Back electrode 7 Reflective insulating layer 8 Light emitting layer 9 Transparent electrode 12A, 12B Current collecting band routing structure 20A, 20B Current collecting band 21 Through hole 22A, 22B Auxiliary current collecting member 23 Conductive member

Claims (4)

[Claims] 1. An electroluminescent device comprising a back electrode, a reflective insulating layer, a light emitting layer and a transparent electrode laminated on each other, and a current collecting band formed on the transparent electrode, and a lead from the current collecting band of the back electrode and the transparent electrode. In a state in which it is sandwiched and sealed with a skin film from above and below in a state of being led out, a pair of current collecting bands are arranged facing each other at the lead-out side end and the opposite side end of the transparent electrode, and both current collecting bands are An electroluminescent lamp characterized in that it is electrically connected by a conductive member arranged around a back electrode. 2. The structure for drawing out a current collecting band according to claim 1, wherein an auxiliary current collecting member is formed on the upper surface of the transparent electrode, and the auxiliary current collecting member and the current collecting band formed on the lower surface of the transparent electrode are provided. An electroluminescent lamp characterized in that it is electrically connected through a through hole and the auxiliary current collecting member is connected to an end of a conductive member. 3. The current-collecting band lead-out structure according to claim 1, wherein the film-shaped auxiliary current collecting member detours the peripheral portion of the transparent electrode from the current collecting band formed on the lower surface of the transparent electrode, and the upper surface thereof. The electroluminescent lamp is characterized in that the extending end is connected to the end of the conductive member. 4. The current-collecting band lead-out structure according to claim 1, wherein an auxiliary current-collecting member is formed on the upper surface of the transparent electrode, the end portion of which is led out to the outside of the outer film, and the lead-out end portion is made of a conductive member. An electroluminescent lamp characterized in that it is connected to the end of the.