JPH0135440Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to the structure of an EL (Electro-Luminescence) element.

[Conventional technology]

EL elements are useful as surface light sources that can be selected from a variety of shapes and sizes, and are being put into practical use as lighting or instruction/display panels for special purposes. As shown in FIG. 4, the structure of a conventional EL element consists of one back electrode 1 made of an Al substrate or the like and the other transparent electrode film 5 made of a polyester film or the like on which indium oxide (ITO) or the like is vapor-deposited. In between, a dielectric layer 3 consisting of an inorganic high dielectric material such as barium titanate (BaTiO ₃ ) dispersed in a thermoplastic binder whose dielectric constant has been increased by cyanoethylation, etc. and a phosphor such as ZnS are heated in the same manner as above. It has a laminated structure in which a light emitting layer 4 dispersed in a plastic binder is interposed, a back electrode 1 and a transparent electrode film 5.
A lead terminal 8 is attached to one end of each of the elements, and the entire element is covered with a water-capturing film 6, 6' and a moisture-proof film 7, thereby sealing the inside of the element. When such an EL element is used as a backlight for displaying patterns such as characters and figures using a positive film, etc., as shown in FIG. was used by illuminating the entire positive film F from below.

[Problem that the invention attempts to solve]

However, in conventional pattern display, it is necessary to manufacture the positive film F on which the characters, figures, etc. to be displayed are formed separately from the EL element, which increases the cost accordingly. When illuminating from below, the entire surface of the display film F is illuminated, including not only the display pattern portion but also the base portion which does not necessarily need to be illuminated, resulting in waste of light emitting power corresponding to the base portion.
Furthermore, because this ground part is forced to emit light,
There was a disadvantage that it was not possible to downsize the inverter for driving the EL elements. In view of these circumstances, the present invention provides an EL element that can simplify the device for pattern display, reduce manufacturing costs and drive power, and provide excellent pattern display.

[Means and actions for solving problems]

In the EL device according to the present invention, a display pattern made of an insulating material is formed on a back electrode, and a dielectric layer and a light emitting layer are further laminated in this order. Therefore, when an electric field is applied between the back electrode and the transparent electrode by the device drive power source, only the display pattern portion emits light, and the other portions, which are not coated with an insulating material, do not emit light. That is, any pattern can be displayed using only the EL elements without using a displaying positive film or the like as in the conventional case. Furthermore, element drive power is used to emit light only in the display pattern portion.

〔Example〕

FIGS. 1 and 2 are diagrams showing one embodiment of an EL element according to the present invention. In the figure, 1 is
A back electrode made of an Al plate or the like; 2 is an insulating voltage layer in which a display pattern to be displayed is formed using an insulating material such as epoxy resin on the back electrode 1 by printing or other methods; 3 is the back electrode 1 or insulation Pressure-resistant layer 2
On top is a dielectric layer formed by dispersing a high dielectric material such as BaTio ₃ in a thermoplastic binder whose dielectric constant has been increased by cyanoethylation, making it into a paste with a solvent, printing and drying it, and 4 a dielectric layer such as ZnS etc. A light-emitting layer made of a paste made by dispersing a phosphor in a thermoplastic binder, 5 is ITO
6 and 6' are nylon-based water absorption layer films that cover the back electrode 1 or the transparent electrode film 5, and 7 is a fluorine-based film that covers the entire element. The moisture-proof films 8 and 8' are lead terminals connected to the back electrode 1 or the transparent electrode film 5.

Since the EL element according to the present invention is constructed as described above, when an electric field is applied to the back electrode 1 and the transparent electrode film 5 via the lead terminals 8 and 8',
For example, as shown in FIG. 2, the light-emitting layer 3 emits light according to the display pattern D of the dielectric strength layer 2, and the light-emitting layer 3 in the portion where the dielectric strength layer 2 is not formed on the back electrode 1
does not emit light as the ground part d. Further, at this time, no power is consumed for light emission in the light emitting layer 3 corresponding to the ground portion d. Therefore, any pattern can be displayed by the dielectric strength layer 2 without using a conventional positive film for display, and the base portion d
Since the power consumption is reduced, the size of the inverter for driving the EL element can be reduced. Furthermore, in conventional positive films, the display pattern formed thereon is exposed, and the contents of the display pattern can be known in advance before backlighting.
EL elements are extremely effective as displays because a display pattern appears on the plain surface of the element. Characters and lines that make up the display pattern are 0.1
It is displayed clearly and minutely on the order of mm, and the strength of the emitted light intensity can be changed by adjusting the thickness of the dielectric breakdown layer 2, thereby making it possible to subtly express display contrast such as blurring.
In addition, when manufacturing the device, it can be manufactured using almost the same manufacturing process as a conventional EL device without using a through-hole substrate or transparent electrode etching method, and the manufacturing cost is hardly increased.

[Effect of idea]

As described above, the EL element of the present invention can be simplified as a pattern display device, reduce manufacturing costs, and reduce driving power. , can be used for general displays including constellation charts, etc.
It has extremely excellent advantages in actual use.

[Brief explanation of the drawing]

Figure 1 is a partial cross-sectional view showing the structure of the EL element of the present invention, Figure 2 is a perspective view showing the state of pattern display of the EL element of the present invention, and Figures 3 and 4 are the conventional EL element.
FIG. 2 is a plan view and a vertical cross-sectional view showing the structure of an EL element. DESCRIPTION OF SYMBOLS 1...Back electrode, 2...Dielectric strength layer, 3...Dielectric layer, 4...Light emitting layer, 5...Transparent electrode film, 7...Moisture proof film, F...Positive film for display.

Claims (1)

[Scope of utility model registration request] An EL element comprising a light-emitting layer and a dielectric layer interposed between a transparent electrode and a back electrode and covered with a moisture-proof film, characterized in that a display pattern made of an insulating material is formed on the back electrode. element.