JPH0638396Y2 - Edge emitting EL element unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to an edge emitting EL element unit using an edge emitting EL element which is one of light emitting elements.

2. Description of the Related Art In recent years, various light emitting elements have been developed with the development of electrophotographic printers. As such a light emitting element, for example, there is an EL (electro-luminescence) element, but it has been desired to improve the emission luminance which tends to be insufficient. Therefore, an edge-emitting type EL has been developed that exhibits a light emission luminance about 100 times that of a conventional EL whose top surface emits light. This is an optical waveguide formed by surrounding a thin film-like active layer made of zinc sulfide containing an active element with a dielectric layer, and an extremely flat light is irradiated from the end face of the active layer. ,
Due to its high brightness, it is expected to be used in printer heads and the like.

Therefore, an edge-emitting type with such an edge-emitting type EL connected in series
The structure of the EL element array 1 will be described with reference to FIGS. 4 and 5. First, as illustrated in FIG. 5, an edge emitting EL
In the element 2, an EL element layer is formed by surrounding a thin film active layer 3 made of zinc sulfide or the like containing an active element such as manganese with dielectric layers 4 and 5 from above and below, and electrode layers 6 and 7 are formed on the upper and lower surfaces thereof. It has a structure that has formed. Then, as illustrated in FIG. 4, the edge emitting EL element array 1 is provided by dividing and forming a large number of the edge emitting EL elements 2 on the insulating substrate 8 by a thin film technique. .

In such a configuration, a drive circuit (not shown) is connected to the edge emitting EL element array 1 to selectively drive the edge emitting EL elements 2 to emit light, thereby producing an electrophotographic printer head. Can be used as

Problems to be Solved by the Invention Since the edge emitting EL element 2 as described above is deteriorated due to contact with environmental gas or the like, the light emitting edge or the like is covered with a transparent protective film when actually manufactured. Generally, a thermosetting resin or the like is used as such a transparent protective film, but since it has a high viscosity and a large surface tension, it tends to be curved at the corners of an object covered by the surface. .

Therefore, as illustrated in FIG. 6, the edge emitting EL device 2
In the transparent protective film 9 formed in the above, the portion covering the front edge portion of the upper electrode layer 6 tends to be curved, and in this case, since the light emitting end surface is covered with the curved transparent member, the emitted light is refracted. And the performance of the edge emitting EL element 2 is deteriorated due to scattering or the like.

Means for Solving the Problem An edge emitting EL element in which a lower electrode layer, an EL element layer, and an upper electrode layer are sequentially formed on a substrate is provided.
A reflection member having a reflection surface inclined with respect to the light emission direction of the element is arranged to face the light emitting end surface of the EL element layer, and the end surface emitting type EL
A transparent protective film is provided to continuously cover the element and the reflecting member.

The reflective member having a reflective surface inclined with respect to the light emitting direction of the edge-emitting EL element is arranged to face the light-emitting end surface of the EL element layer.
By providing a transparent protective film that continuously covers the edge-emitting EL element and the reflecting member, the upper surfaces of the edge-emitting EL element and the reflecting member become continuous, so the transparent protective film formed on this Has good smoothness, and the light emitted from the edge-emitting EL element is reflected by the reflecting surface of the reflecting member and passes through the portion of the transparent protective film having good smoothness, so that light scattering is small.

Embodiment An embodiment of the present invention will be described with reference to FIGS. The same parts as those of the above-described conventional example are designated by the same names and reference numerals, and description thereof will be omitted. In this edge emitting EL element unit 10, the edge emitting EL element array 1 mounted in parallel on the aluminum frame 11 and the elongated reflecting member 12 are continuously covered with the transparent protective film 13. Here, the reflecting surface 14 of the reflecting member 12 inclined at 45 degrees with respect to the light emitting direction of the edge emitting EL element 2 faces the light emitting edge of the edge emitting EL element array 1.

Therefore, the edge emitting EL element unit having the above structure
An example of the manufacturing process of 10 will be described with reference to FIGS. First, as illustrated in FIG. 3A, the lower electrode layer 7 made of Ti or the like is formed by patterning a thin film formed by sputtering on the insulating substrate 8 by photoetching. Next, as illustrated in FIGS. 3B and 3C, a thickness of 3000 is formed on the formed lower electrode layer 7.
Å Y ₂ O ₃ dielectric layer 5 and Mn-doped thickness 1000
An EL device layer is formed by sequentially stacking an active layer 3 made of ZnS of 0 Å and a dielectric layer 4 made of Y ₂ O _{3 of} 3000 Å by vapor deposition or the like, and an upper electrode layer 6 is formed thereon by Cr or the like. To do. Therefore,
Each of the layers 3 to 6 is continuously etched by the ion milling method to form a plurality of edge-emitting EL elements 2 separately. Next, as illustrated in FIG. 3D, a V groove having a predetermined depth is formed on the back surface of the front edge portion of the insulating substrate 8 by a diamond wheel or the like in parallel with the continuous direction of the edge-emitting EL elements 2. Then, by breaking, the edge emitting EL element array 1 in which the edge emitting EL elements 2 are continuously formed on the insulating substrate 8 is obtained.

Therefore, in the edge emitting EL unit 10 of this embodiment, the third
As illustrated in FIG. 2E, an edge emitting EL element array 1
And the reflection member 12 are arranged in parallel on the aluminum frame 11 with the light emitting end surface and the reflection surface 14 facing each other, and fixed by adhesion or the like, to the electrodes 6 and 7 of the end surface emission type EL element array 1. Wiring (not shown) is performed. Then, for example, the integrally fixed members 1 to 14 are dipped in an epoxy resin having a predetermined viscosity and pulled up at a constant speed, and as shown in FIG. The manufacture of the edge-emitting EL element unit 10 on which the transparent protective film 13 that continuously covers the reflecting member 12 is formed is completed.

The edge-emitting EL element unit 10 thus formed
Is an edge-emitting type, as illustrated in FIG. 1 and FIG.
Since the upper surfaces of the EL element array 1 and the reflecting member 12 are continuous flat surfaces, the transparent protective film 13 formed thereon has good smoothness, and the light emitted from each edge emitting EL element 2 is reflected. Face 14
The light is not scattered due to refraction of the transparent protective film 13, which is reflected by the transparent protective film 13 and is transmitted through a portion of the transparent protective film 13 having good smoothness.

Therefore, a high performance line head (not shown) can be manufactured by combining a drive circuit, a rod lens array and the like with this edge emitting EL element unit 10.

Effect of the Invention As described above, the present invention disposes a reflecting member having a reflecting surface inclined with respect to the light emitting direction of the edge-emitting EL element to face the light-emitting end surface of the EL element layer and reflects the edge-emitting EL element. By providing a transparent protective film that continuously covers the member, the upper surfaces of the edge-emitting EL element and the reflective member are continuous, so the transparent protective film formed on this has good smoothness. The light emitted from the edge-emitting EL element is reflected by the reflecting surface of the reflecting member and is transmitted through the portion of the transparent protective film having good smoothness, which is a high-performance edge-emitting EL element with less scattering of the emitted light. A unit can be formed, and the edge emitting EL element has effects such as good protection from environmental gas and stable performance.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional side view showing an embodiment of the present invention, FIG. 2 is a perspective view, FIG. 3 is a manufacturing process drawing, and FIG. 4 is a conventional edge emitting EL device. FIG. 5 is a perspective view of the array, FIG. 5 is a perspective view of an edge emitting EL element, and FIG. 6 is a vertical side view. 3 to 5 ... EL element layer, 6 ... upper electrode layer, 7 ... lower electrode layer, 8 ... substrate, 10 ... edge emitting EL element unit,
12 …… Reflecting member, 13 …… Transparent protective film, 14 …… Reflecting surface

Claims (1)

[Scope of utility model registration request] 1. An edge emitting EL element having a lower electrode layer, an EL element layer and an upper electrode layer sequentially laminated on a substrate, and a reflecting surface inclined with respect to the light emitting direction of the edge emitting EL element. An edge-emitting EL element unit, characterized in that a reflective member having a light-emitting end surface of the EL element layer is disposed so as to face the edge-emitting EL element, and a transparent protective film continuously covering the edge-emitting EL element and the reflective member is provided. .