JPH0451492A - Color el display - Google Patents

Abstract

PURPOSE:To heighten the operational reliability of a color EL display in the application thereof to a laminated type display panel and at the same time to suppress a useless power loss in an insulating layer for electrically separating EL elements from each other, which is consequent upon the process of laminating the EL elements upon one another by arranging the insulating layer between the respective EL elements, and then connecting upper and lower matrix electrodes holding the insulating layer therebetween respectively to data-side drivers whereby both of the matrix electrodes are made independent of each other as data electrodes so as to be driven together. CONSTITUTION:A scanning electrode 60 for a red EL element 1 and a scanning electrode 70 for a green EL element 2 are positioned respectively on both ends of an insulating layer 41 while a data electrode 80 for the green EL element 2 and a data electrode 90 for a blue EL element 3 are positioned respectively on both ends of an insulating layer 42. A DR driver 11 as a data-side driver is connected to a matrix electrode 50, an SR driver 12 as a scanning-side driver to the scanning matrix electrode 60, an SG driver 14 as a scanning-side driver to the scanning matrix electrode 70, a DG driver 13 as a data-side driver to the data matrix electrode 80, a DB driver 15 as a data side driver to the data matrix electrode 90, and an SB driver 16 as a scanning-side driver to a matrix electrode 100 so that all of the matrix electrodes may be driven.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a self-luminous color EL display device that displays multiple colors.

The color display method in conventional technology display devices is usually R-G.
- Arbitrary multicolor display is performed by spatially mixing colors such as B color. Further, as a method for spatial color mixing, there is a three-dimensional color mixing method in which each light emitting body is arranged three-dimensionally, which can be realized in an EL display device or the like. From the point of view of resolution, this is the same as monochrome display, and furthermore, because of the three-dimensional color mixture, separation of the emitted primary colors does not occur even if the pixels are enlarged, so a clearer multicolor display is possible.

FIG. 4 shows a configuration diagram of a conventional color EL display device, and here a multicolor display using three colors of R, G, and B will be described. 1 is an EL element having an R color emitter layer, 2 is a G
3 is an EL element with a B color phosphor layer; 5 is a data electrode of the R color EL element 1; 6 is a scanning electrode of the R color EL element 1; 7 is a G Data electrode of color EL element 2, 8 is scanning electrode of G color EL element 2, 9 is B color E
A data electrode of the L element 3, 10 a scanning electrode of the B color EL element 3, and 41 and 42 insulator layers for electrically insulating each EL element when the EL elements are stacked. Each electrode 5~
Reference numerals 10 are in a perpendicular relationship between the upper and lower sides, and serve as matrix electrodes. It also has transparent electrodes to facilitate color mixing. These are formed on the glass substrate 20 and
I- Configure the display panel.

11 Data side (DR) driver of R color EL element 1, 1
2 is a scanning side (SR) driver for R color E L element 1, 13
is the data side (DC) driver of the G color BL element 2, 14
is the scanning side (SG) driver of the G color B L element, 15 is the data side (DB) driver of the B color EL element 3, and 16 is the B
A scanning side (SB) driver of the color EL element 3, 17 is a modulation pulse generation circuit that supplies a modulation pulse voltage to each data side driver 1.1.13.15, and 18 is a writing circuit for each scanning side driver 12.14.16. A write pulse generation circuit 19 supplies a pulse voltage, and a control circuit 19 receives an input signal and controls the timing of each pulse generation circuit 17, 18 and each driver 11 to 16. The input signal is a data display signal (R3 for R color EL element 1, G color E T-
BS for GSXB color EL element 3 for element 2),
It consists of a data transfer lock signal CLK, a horizontal synchronization signal HD, and a vertical synchronization signal VD.

Each driver operates as a dedicated driver for driving each EI-element. Each scanning side driver 12゜14, 16
performs line sequential scanning and applies a write pulse voltage from the write pulse generation circuit 18, and each data side driver LL 13.15 applies a modulated pulse voltage from the modulated pulse generation circuit 17 in response to each data display signal. By superimposing them, each of the EL elements 1 to 3 is made to emit light, and the overall spatial color mixture enables multicolor display. Normally, the modulation pulse voltage (Vm) is approximately 60v1 as the driving voltage.
A write pulse voltage (Vw) of about -200V (about 260V for refresh) is used.

Problems to be Solved by the Invention However, in the above configuration, the data electrode and the scan electrode face each other with an insulator layer in between. In other words, the insulator layer 4
1, the data electrode 7 and the scan electrode 6 are opposed to each other, and the insulator layer 42 is opposed to the data electrode 9 and the scan electrode 8. On the other hand, since each EL element is driven simultaneously, there is a maximum of Vi=V between the insulator layers where the data electrode and the scan electrode intersect.
A voltage of m+Vw-260v will be applied. This voltage value is the same as the voltage applied to a normal EL element that emits light. Therefore, if there are variations in the withstand voltage characteristics of the insulating layer or deterioration of the dielectric strength voltage occurs, a fatal defect such as damage to the EL element or driver will occur due to dielectric breakdown.

Furthermore, even though it is an insulator layer, it has a capacitance C4, so for example, if the number of scanning electrodes is n and the frame frequency is f, the driving power Pi consumed for this is Pi=CiX
It is expressed as Vi2XnXf.

Since the driving power increases in proportion to the square of the voltage, there has been a problem in that power loss due to the insulating layer to which a high voltage is applied cannot be ignored.

In view of these points, the present invention provides a color E which is highly reliable as a stacked display panel and which suppresses wasteful power loss in the insulator layer for electrically isolating the E L elements due to stacking.
The purpose of the present invention is to provide an L display device.

Means for Solving the Problems The present invention provides an EL element in which matrix electrodes for data and scanning are arranged so as to be sandwiched against a light emitting layer, and a stacked EL display panel formed by stacking the EL elements. Regarding this, an insulating layer is provided between each EL element, and the upper and lower matrix electrodes sandwiching the insulating layer have data (
This is a color EL display device characterized in that it is driven by being connected to an independent data (scanning) side driver as a scanning) electrode.

Effect of the present invention With the above-described configuration, even if the EL elements face each other with an insulating layer in between, the opposing electrodes become a data electrode for a data electrode and a scan electrode for a scan electrode, so that the potential difference between the two electrodes is reduced. Since the voltage can be suppressed from O to a low voltage of about several tens of volts, it is possible to improve the reliability of the withstand voltage of the insulating layer and to significantly reduce power loss due to the insulating layer.

Embodiment FIG. 1 shows a configuration diagram of a color EL display device in a first embodiment of the present invention. Similar to the conventional example, a multicolor display using three colors, RGB, will be described here. E
The order in which the L elements are stacked is the same as in the conventional example, but the function and electrode pattern of each electrode are unique. First, regarding the functions of each matrix electrode 50 to 100, 50 is a data electrode of R color EL element 1, 60 is a scan electrode of R color EL element 1, 70 is a scan electrode of G color EL element 2, and 80 is G
The data electrode 90 of the color EL element 2 is operated as a data electrode of the B color EL element 3, and the reference numeral 100 is a scanning electrode of the B color EL element 3. Corresponding to the functions of each matrix electrode 50 to 100, the matrix electrode 50 has a DR driver 11 as a data side driver, the matrix electrode 60 has an SR driver 12 as a scan side driver, and the matrix electrode 70 has a SG driver as a scan side driver. 14. The matrix electrode 80 has a data side driver DG driver 13, the matrix electrode 90 has a data side driver DB driver 15, and the matrix electrode 100 has a scanning side driver S
Connect and drive the B driver 16.

The operation of the color EL display device of the first embodiment configured as described above will be described below.

Each data side driver IL 13.15 and each scanning side driver 12.14.16 are synchronized as a whole, and each E L element 1
Data writing to 2.3 and line sequential scanning are performed.

Here, the voltage potential difference of the electrodes between each EL element (insulator layer 4L
42), the scanning electrodes 60 of the R color EL element 1 and the scanning electrodes 70 of the G color BL element 2 are located at both ends of the insulating layer 41, and the G color EL elements are located at both ends of the insulating layer 42. A data electrode 80 of element 2 and a data electrode 90 of B color EL element 3 are located. The write pulse voltage of the scan electrode 60 is set to 7wR8.
The write pulse voltage of the scan electrode 70 is Vwc, the modulation pulse voltage of the data electrode 80 is mG, and the data electrode 90 is
The modulated pulse voltage is Vm.

shall be. The voltage Vi applied to the insulator layer 41 is V
i RG= l V WRV We Waist insulation layer 4
The voltage Vic++ applied to 2 is V 1aB= l V
mc-Vm.

It is. Assuming that each EL element has the same emission characteristics,
The modulation pulse voltage Vm and write pulse voltage Vw as shown in this figure can be commonly supplied to each data side driver and scanning side driver. In this case, the voltage between the insulator layers is ViRG-〇, Vi. 6=0 or Vm (Ol when both EL elements emit or do not emit light; Vm when only one EL element emits or does not emit light: Vm<Vw),
Let the maximum voltage Vi, between the insulator layers be at least Vi,=V
It is possible to suppress the voltage level to a low voltage level of m<Vw. Generally, in manufacturing EL elements, Vm, ≠Vm, ≠Vm, .
.

Although variations occur such as ■wR≠■wG≠■wB, the electrical characteristics of the EL display panel are Vm, i:;

It is designed with VwR'=VWe', VwB#Vw. Therefore, the maximum voltage Vi between the insulator layers is 0≦Vi.

It can be considered that the range is ≦Vm+α, (VW (however, α1 is the amount of variation). From this, the voltage between the insulator layers can be reduced to about 174 compared to the conventional one, and the power loss can be reduced to about 1/6.

As shown in FIG. 2, the structure of the EL display panel includes matrix electrodes 60 and 70 sandwiching an insulating layer 41.
and a matrix electrode 80.9 sandwiching the insulator layer 42.
0, by arranging the opposing electrodes in the same parallel pattern, the number of data electrodes of each EL element and the transfer direction of the display data signal can be made the same, so the display data signal and control signal can be It is possible to drive the

As described above, according to this embodiment, the maximum voltage Vi between the insulating layers can be suppressed to a very low voltage of 0≦Vi, ≦Vm+α, and <Vw, so the withstand voltage margin for the insulating layers can be greatly improved. It is possible to reduce power consumption.

FIG. 3 shows a configuration diagram of a color EL display device according to a second embodiment of the present invention. The order of stacking the EL elements is basically the same as in the conventional example.

Note that the insulating layer is interposed only between the G color EL element 2 and the B color EL element 3. First, each matrix electrode 51-1
01, 51 is a data electrode of R color EL element 1, 61 is a common scanning electrode of R color EL element 1 and G color EL element 2, 81 is a data electrode of G color EL element 2, and 91 is a data electrode of G color EL element 2. The electrode 101 is operated as a data electrode of the B color EL element 3, and as a scan electrode of the B color EL element 3. The matrix electrode 51 corresponds to the function of each matrix electrode 51 to 101.
DR driver 11 as a data side driver, SRG driver 21 as a scanning side driver on the matrix electrode 61,
A DC driver 13 as a data side driver is connected to the matrix electrode 81, a DB driver 15 as a data side driver is connected to the matrix electrode 91, and an SB driver 16 as a scan side driver is connected to the matrix electrode 101 for driving.

The operation of the color EL display device of this embodiment configured as described above will be described below.

Each data side driver LL 13.15 and each scanning side driver 1621 are synchronized as a whole, and each E L element 1, 2゜3
Data writing and line sequential scanning are performed. Since 61 is a common scanning electrode for the R color EL element 1 and the G color EL element 2, an insulator between the R color EL element 1 and the G color EL element 2 as shown in the first embodiment is used. Since the layer 41 is not required and only one set of matrix electrodes is required, the configuration of the EL element panel is also simplified. By using the shared scan electrode 61, the number of scan side drivers can be reduced from two sets to one set. However, the drive current capacity of the SRG driver 21, which serves as the shared scanning side driver, is as follows:
Naturally, it requires twice as much as the conventional method. As is clear from the figure, the electrodes located at both ends of the insulator layer 42 are the data electrode 81 of the G color EL element 2 and the notator electrode 91 of the B color EL element 3. Therefore, the voltage (12) applied to both ends of the insulator layer 42 is 0≦Vi as in the first embodiment.
It can be considered that the range is 2≦Vm+α2 (VW (however, α2 is the amount of variation).Assuming that the electrical characteristics of the EL display panel are the same as those of the first embodiment, in this case, Vi
2 is a function only of the modulation pulse voltage Vm and has no relation to the write pulse voltage Vw, so the variation amount α is α2<
Since αl, it is possible to make Vi2<Vi as a result. In this way, in the EL display panel of this embodiment, if each EL element is one unit, an insulator layer is interposed in every other unit, and the parts with the insulator layer are used as data electrodes, and the parts without an insulator layer are used as scan electrodes. Therefore, the breakdown voltage between the insulator layers can be reduced to a low voltage of only the modulation voltage Vm. It is preferable from the viewpoint of control that the data electrodes facing the insulating layer have the same pattern as shown in FIG.

As described above, according to this embodiment, the voltage applied to the insulator layer is only the modulation voltage component, so that Vi2<Vi,
This makes it possible to further improve the withstand voltage margin and reduce driving power compared to the first embodiment.

Effects of the Invention As described in 2, according to the present invention, with respect to the insulator layer portion of a laminated EL panel laminated with an insulator layer in between, the matrix electrodes located at both ends of the insulator layer are both data-based. By driving it as an electrode or a scanning electrode, the voltage Vi applied between the insulating layers can be reduced to at least Vi
It is suppressed to a low voltage level of #Vm+α<(Vm+Vw). Therefore, the dielectric strength voltage for the insulator layer can be reduced to about 174 and the power loss to about 1716 compared to the conventional method, so that the reliability of the EL display panel can be improved and the driving power can be significantly reduced, which has great practical effects.

[Brief Description of the Drawings] Fig. 1 is a block diagram of a color EL display device according to a first embodiment of the present invention, Fig. 2 is a block diagram of a color EL display panel of the same embodiment, and Fig. 3 is a block diagram of a color EL display device according to the first embodiment of the present invention. FIG. 4 is a block diagram of a color EL display device in the second embodiment, and FIG. 4 is a block diagram of a conventional color display device. 1...R color EL element, 2...G color EL element
Element, 3... B color EL element, 50.51...
...Data electrode, 80°81...Data electrode, 90.91...Data electrode, 60°61...
... Scanning electrode, 70 ... Scanning electrode, 100
．． 101...Scanning electrode, 41.42...
- Insulator layer, IL 13.15... Data side driver, 21... Scanning side drive.

Claims (4)

[Claims] (1) EL element in which matrix electrodes for data and scanning are arranged so as to be sandwiched against the light emitter layer;
Regarding a stacked EL display panel formed by stacking elements,
An insulator layer is provided between each EL element, and the upper and lower matrix electrodes sandwiching the insulator layer are used for data (scanning).
A color EL display device characterized in that it is driven by being connected to an independent data (scanning) side driver as an electrode. (2) The color EL display device according to claim 1, wherein the matrix electrodes sandwiching the insulating layer have the same pattern. (3) Concerning a stacked EL display panel in which one unit is an EL element in which matrix electrodes for data and scanning are arranged so as to be sandwiched against a light-emitting layer, and the EL elements are stacked every other unit with an insulating layer interposed therebetween. At least the upper and lower matrix electrodes with the insulating layer sandwiched therebetween were both used as data electrodes, and the matrix electrodes between the EL elements without the insulating layer were connected as shared scanning electrodes and driven by respective independent dedicated drivers. A color EL display device characterized by: (4) The color EL display device according to claim (3), wherein the matrix electrodes sandwiching the insulating layer have the same pattern.