JP2555783Y2 - Display device - Google Patents

Description

The present invention relates to a display device, and more particularly, to a display device capable of performing a multicolor display using a thin film EL element.

(B) Problems to be Solved by the Prior Art / Invention As a conventional display device, for example, a thin-film EL device capable of multicolor display as shown in FIGS. 5 and 6 is known.

Structure of the thin film EL element shown in Fig. 5, the glass substrate 1 transparent electrode 2 on, were sequentially laminated the first insulating layer 3, Z _n S and M _n
The first light-emitting layer 4, Z _n S and T _b F ₃ Metropolitan second light-emitting layer 4a, a third light-emitting layer 4b and the first insulating layer composed of the C _a S and E _u consisting of consisting of 3, a second insulating layer 5 is formed on the first light emitting layer 4, the second light emitting layer 4 a, and the third light emitting layer 4 b, and a back electrode is formed on the second insulating layer 5. 6 to form a thin-film EL element capable of multicolor display.

However, the above-mentioned conventional one has three light-emitting layers 4, 4a, 4
Since the light emission luminance characteristics of b differ, the drive voltage must be changed according to the light emitting layers 4, 4a, and 4b in order to obtain the same brightness.

In addition, the first light emitting layer 4, the second light emitting layer 4a, the third light emitting layer 4
b is formed by etching and lift-off processing. In particular, since the second light emitting layer 4a contains a fluorine compound, the second light emitting layer 4a also has a disadvantage that film peeling is easily induced by the influence of water.

Further, as shown in FIG.
Is strong, but the green spectrum of a and b
Has a disadvantage that the yellow spectrum is weak and the emission luminance balance of each color is poor.

This invention has been made in view of the above points,
It is an object of the present invention to provide a display device which can solve the above-mentioned conventional drawbacks and can perform multicolor display using a thin-film EL element having one light-emitting layer.

(C) Means for Solving the Problem The display device of the present invention has a Zn substrate on a glass substrate.
After forming a light emitting layer composed of a mixture of S, Sm and F and the glass substrate temperature of 270 ° C. to 300 ° C. for accelerating hot electrons of the light emitting layer to a thickness of 1000 to 1500 ° C. A thin film EL device having a ZnS electron acceleration layer subjected to vacuum heat treatment at
A filter for selecting the emission spectrum of the EL element.

According to the present invention, a light emitting layer composed of a mixture of ZnS, Sm and F is formed on a glass substrate, and the temperature of the glass substrate is set at 270 ° C. for accelerating hot electrons in the light emitting layer.
After forming to a thickness of 1000 to 1500 Å at ~ 300 ℃, 600 ℃
The electron acceleration layer made of ZnS subjected to a vacuum heat treatment at a temperature of 700 ° C. to 700 ° C. accelerates hot electrons in the light emitting layer.

Therefore, (4f) ⁵ electrons of S _m ion is the luminescent center is an excited state of easily, the light-emitting layer is output spectrum of wavelength 565 nm, the spectrum of the spectrum and the wavelength 650nm wavelength 600 nm.

Then, by using a filter, each light emission of green, yellow, and red can be extracted, so that a multi-color display can be performed by a thin film EL element having one light emitting layer.

(E) Embodiment An embodiment of the display device according to the present invention will be described with reference to FIGS.

The same parts as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

In the figure, 7 is the thin-film EL elements of the display device, 8 is an electron acceleration layer consisting of Z _n S formed by electron beam deposition on the first insulating layer 3 of the thin-film EL element 7, the electron acceleration layer Reference numeral 8 denotes a film formed at a substrate temperature of 270 ° C. to 300 ° C. to a thickness of 1000 to 1500 ° C., and then subjected to a vacuum heat treatment at 600 ° C. to 700 ° C.

9 is a light emitting layer comprising a mixture of Z _n S and S _m and F,
The light-emitting layer 9 is obtained by film formation by sputtering using a mixture target of Z _n S and S _m and F.

10a, 10b, and 10c are back electrodes formed on the second insulating layer 5, 11a, 11b, and 11c are filters provided in close contact with the glass substrate 1, and the filter 11a has a wavelength of 565 nm of the light emitting layer 4.
Filter characteristic Af for extracting green spectrum A of
(FIG. 4), and the filter 11b has a filter characteristic Bf for extracting a yellow spectrum B having a wavelength of 600 nm of the light emitting layer 4. Similarly, the filter 11c has a wavelength of 6 nm of the light emitting layer 4.
Filter characteristics for extracting 50nm red spectrum C
It is configured to have Cf.

Now, in the thin-film EL element 7, the electron acceleration layer 8 (4f) ⁵ electrons of S _m ion is the luminescent center from accelerating hot electrons in the light emitting layer 9 becomes excited easily state, rising characteristics of the light emitting, Light emission luminance characteristics and light emission efficiency are improved.

The spectral intensities of the green spectrum A, the yellow spectrum B, and the red spectrum C are substantially the same as shown in FIG.

In thus constructed display device, when looking at the display device in the eye 12, the position P ₁ of the thin-film EL element 7 corresponding to the back electrode 10a is visible in the yellow and the back electrode
The position P ₂ corresponding to 10b looks green, likewise, the back electrode 1
Position P ₃ corresponding to the 0c appear in red.

Therefore, multi-color display can be performed by the thin film EL element 7 and the filters 11a, 11b, 11c.

 Of course, a display using an intermediate color is also possible.

(F) Effects of the Invention According to the display device according to the invention, the configuration described above provides the following effects.

Multicolor display is possible with an inexpensive configuration.

 Moreover, the emission luminances of green, yellow, and red are substantially equal.

Since the light emission is performed by one light emitting layer, the driving circuit is inexpensive.

The thin film forming process is simple, and film peeling does not occur.

[Brief description of the drawings]

1 to 4 show an embodiment of the display device according to the present invention. FIG. 1 is a sectional view, FIG. 2 is a front view, and FIG.
The figure shows the emission spectrum, and FIG. 4 is a characteristic diagram of the filter. 5 and 6 show a conventional example, FIG. 5 is a sectional view, and FIG. 6 is a view showing an emission spectrum. Explanation of main symbols 1: glass substrate 2: transparent electrode 3: first insulating layer 5: second insulating layer 7: thin-film EL element 8: electron accelerating layer 9: light emitting layer 10a, 10b, 10c: back electrode 11a , 11b, 11c: Filter

Claims (1)

(57) [Scope of request for utility model registration] 1. A light emitting layer composed of a mixture of ZnS, Sm and F on a glass substrate and a temperature of the glass substrate of 270 ° C. to 300 ° C. for accelerating hot electrons in the light emitting layer.
After forming to a thickness of 1000 ~ 1500 Å at 600 ℃ ~ 700 ℃
And a filter for selecting an emission spectrum of the thin-film EL element, the thin-film EL element having an electron accelerating layer made of ZnS subjected to vacuum heat treatment.