JP3326857B2 - EL display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EL display device using an EL (electroluminescence) element which emits light when an AC voltage is applied, and more particularly, to a large number of scanning electrodes and a large number of data electrodes orthogonal thereto. The present invention relates to an EL display device that displays various image data by controlling light emission of each pixel formed at each intersection.

[0002]

2. Description of the Related Art Conventionally, an EL display device having a pair of electrodes formed on both surfaces of an EL light emitting layer has been known. In this type of EL display device, when an AC voltage is applied between a pair of electrodes, the EL light emitting layer emits light, and characters and the like can be displayed.

However, Zn used as an EL light emitting layer
Since S and the like are also piezoelectric materials, they vibrate when an AC voltage is applied, and this vibration becomes noise. Therefore, various measures have conventionally been taken to prevent noise in this type of EL display device. For example, JP-A-63-5109
As described in JP-A No. 3 (1993) -1995, a light-transmitting plate is provided via a spacer on the surface of a glass plate on which an EL light-emitting layer is formed, and noise generated by the EL light-emitting layer is reduced by the glass plate, the spacer, and the light-transmitting plate. Devices that can be confined in an enclosed space are being considered.

As described in JP-A-63-249895, in an EL display device in which an EL light emitting layer emits light by applying a rectangular alternating voltage, noise is prevented by smoothing the voltage waveform. Devices that perform this are also contemplated.

[0005]

However, a glass plate,
In a device that seals noise in a space surrounded by the spacer and the light-transmitting plate, it is necessary to make the frame large by the size of the spacer and the light-transmitting plate. Therefore, the size of the EL display device is increased, and there are cases where the devices to which the device can be applied are limited.

[0006] Further, E for smoothing the voltage waveform in the form of a rectangular wave.
In the L display device, the vibration component may not be removed properly depending on the frequency of the vibration component. That is, high-frequency vibration components generated at the rise and fall of the rectangular wave voltage can be removed satisfactorily, but low-frequency vibration components corresponding to the period of the rectangular wave voltage cannot be sufficiently removed. For this reason, the vibration component with the largest noise cannot always be removed, and the noise cannot be sufficiently prevented.

Accordingly, the present invention provides an EL display device which displays various image data by controlling light emission of each pixel formed at each intersection of a large number of scanning electrodes and a large number of data electrodes orthogonal thereto. The purpose was to prevent noise satisfactorily without increasing the size.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an EL light emitting layer which emits light by applying a voltage having an absolute value equal to or higher than a threshold value, and a plurality of EL light emitting layers on one side of the EL light emitting layer. Scanning electrodes arranged in parallel, and on the other surface of the EL light-emitting layer, a plurality of data electrodes arranged in parallel in a direction perpendicular to the scanning electrodes, wherein the scanning electrodes and the data electrodes In the EL display device in which pixels are formed at the respective intersections, a scanning voltage having an absolute value smaller than the threshold value is sequentially applied to the scanning electrodes, and any one of the scanning electrodes to which the scanning voltage is not applied is applied. A scanning voltage applying means for applying an anti-phase voltage having a phase smaller than the threshold value and having a phase opposite to the scanning voltage; Voltage minus voltage Greater in absolute value Ri, and the scanning voltage and the data voltage applying means for applying a reverse polarity of the data voltages, the providing the absolute value of the data voltage of the opposite phase voltage
The gist is an EL display device characterized by being larger than the absolute value of

[0009]

According to the present invention thus constructed, the scanning voltage applying means sequentially applies the scanning voltage having an absolute value smaller than the threshold value of the EL light emitting layer to each scanning electrode, and simultaneously applies the scanning voltage to which no scanning voltage is applied. An antiphase voltage smaller than the threshold and opposite to the scanning voltage is applied to one of the electrodes. The data voltage applying means may apply, to the predetermined data electrode, a data voltage having an absolute value smaller than the threshold value and larger than a value obtained by subtracting the scanning voltage from the threshold value, and having a polarity opposite to the scanning voltage. Apply. Then
In a pixel to which the scanning voltage and the data voltage are applied via the scanning electrode and the data electrode, a voltage higher than the threshold is applied to the EL light emitting layer. Therefore, the EL light emitting layer of the pixel emits light.

On the other hand, in a pixel to which only one of the scanning voltage, the anti-phase voltage, and the data voltage is applied, EL
Since the voltage applied to the light emitting layer is smaller than the threshold, EL
The light emitting layer does not emit light. Further, in a pixel to which the opposite phase voltage and the data voltage are applied, the voltage applied to the EL light emitting layer becomes a difference between the opposite phase voltage and the data voltage and becomes smaller than the threshold value, so that the EL light emitting layer does not emit light. Then, a scanning voltage is sequentially applied to each scanning electrode, and this operation is repeated, whereby a two-dimensional image can be displayed.

The absolute value of the opposite phase voltage is
Since the absolute value is larger than the absolute value, the EL light emitting layer of the pixel to which the scanning voltage is applied and the EL light emitting layer of the pixel to which the opposite phase voltage is applied are independent of whether the data voltage is applied or not.
Voltages of opposite phases are applied to all the pixels .
The EL light emitting layer vibrates by applying a voltage. In this case,
The phases of the vibrations of both EL light emitting layers are reversed from each other. Therefore,
The two vibrations interfere with each other, and the vibration of the entire EL display device is reduced.

Further, if the direction in which the scanning voltage propagates through the scanning electrode and the direction in which the anti-phase voltage applied simultaneously with the scanning voltage propagates through the scanning electrode are the same, the respective Vibrations generated by the EL light emitting layers interfere with each other as follows. That is, although a significant time is required for the scanning voltage and the anti-phase voltage to propagate through the scanning electrode, this configuration makes the position of the EL light-emitting layer to which voltages of opposite phases are applied closer. Will be arranged. For this reason, the vibrations of the EL light emitting layer due to the respective voltages better interfere with each other, and the vibration of the entire EL display device is further reduced.

[0013]

Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram illustrating an EL display device 1 according to a first embodiment. As shown in the figure, in the EL display device 1 of the present embodiment,
On one side of the EL light emitting layer 3, m scanning electrodes Y1 to Ym are arranged in parallel, and on the other side of the EL light emitting layer 3, n data electrodes are arranged in a direction orthogonal to the scanning electrodes Y1 to Ym. The electrodes X1 to Xn are arranged in parallel (m and n are even numbers).
Pixels Z11 to Zmn are formed at intersections between the scanning electrodes Y1 to Ym and the data electrodes X1 to Xn.

The scanning electrodes Y1 to Ym change the protruding direction every two rows and protrude from the edge of the EL light emitting layer 3, and the leading ends thereof are connected to scanning drivers YD1 to YDm, respectively. The scan drivers YD1 to YDm apply three types of voltages VH, −VH, and 0 (V) to the scan electrodes YD1 to YDm based on signals from a control circuit (not shown). It corresponds to an application unit.
Similarly, the data electrodes X1 to Xn protrude from the edge of the EL light emitting layer 3 by changing the protruding direction every two columns, and
1 to XDn. The data drivers XD1 to XDn apply three types of voltages, VM, −VM, and 0 (V), to the data electrodes X1 to Xn based on signals from a control circuit (not shown). It corresponds to an application unit.

Here, the scanning drivers YD1 to YDm and the data drivers XD1 to XDn are well-known driver circuits using FETs (field effect transistors).
Further, the voltages VH and VM are 0 <VM <VH <Vth and VH + VM> with respect to the threshold (light emission start voltage) Vth of the EL light emitting layer 3.
It is set so as to satisfy the relationship of Vth. Therefore, the scanning driver YDi (1 ≦ i ≦ m) and the data driver XDj
(1 ≦ j ≦ n), the scanning electrode Yi and the data electrode X
When a voltage having a magnitude of VH + VM is applied during j, the pixel Zi
The EL light emitting layer 3 belonging to j can emit light.

A first example of a specific operation of the EL display device 1 configured as described above will be described with reference to a time chart of FIG. In FIG. 2, a solid line represents a case where only the pixel Z11 emits light. First, at time t0 to t1, a pulsed voltage -VH is applied to the scan electrode Y1,
A pulse voltage VH is applied to the scan electrode Y2. At the same time, the pulse voltage VM is applied to the data electrode X1, and no voltage is applied to the other electrodes (Y3 to Ym, X2 to Xn).

At this time, when the voltage applied to each pixel Zij is considered as the voltage of the data electrode Xj based on the scanning electrode Yi, the voltage VH + VM (> Vt) is applied to the pixel Z11.
h) is applied, and the EL light emitting layer 3 belonging to the pixel Z11 emits light. The voltage -V is applied to the pixel Z21 in the second row and first column.
H + VM is applied, and the pixel Zh1 in the first column of the other row is applied.
The voltage VM is applied to (3 ≦ h ≦ m). Although not shown, the pixels Z1k in the first row other than the first column (2 ≦ k
.Ltoreq.n), the voltage VH is applied to the pixels Z2 in the second row other than the first column.
A voltage -VH is applied to k. However,
VH, VM, and VH-VM (= | -VH + VM |)
Are smaller than the threshold value Vth, the EL light emitting layers 3 belonging to these pixels Zij do not emit light. Further, since no voltage is applied to the other pixels Zhk (3 ≦ h ≦ m, 2 ≦ k ≦ n), only the pixel Z11 emits light.

A positive voltage is applied to all pixels Z1j in the first row, and a negative voltage is applied to all pixels Z2j in the second row. The EL light emitting layer 3 vibrates due to the application of a voltage. In this case, the EL light emission in both pixels Z1j and Z2j is performed.
The phases of the oscillations of the light emitting layer 3 are reversed. Therefore, the two vibrations interfere with each other, and the vibration of the EL display device 1 as a whole is reduced. That is, in this embodiment, the pulse voltage -VH corresponds to the scanning voltage, the pulse voltage VH corresponds to the opposite phase voltage, and the pulse voltage VM corresponds to the data voltage.

Subsequently, from time t1 to time t2, the scanning electrode Y1
And a pulse voltage -VH is applied to the scan electrode Y2. From time t2 to time t3, the pulse voltage -VH is applied to the scan electrode Y3 and the scan electrode Y
4, a pulse voltage VH is applied to the scan electrode Y3 from time t3 to time t4.
4, a pulse voltage -VH is applied. Similarly, the pulse voltages VH and -H are applied to the scan electrodes Y1 to Ym by time t6 so that the pulse-like voltages applied to the adjacent scan electrodes Yl and Yl-1 (1 is an even number) have the opposite phases. VH is sequentially applied.

At the same time, among the pixels Zi1 to Zin belonging to the row to which the pulse voltage -VH is applied, if there is one to emit light, the pixel Zij (1 ≦ j)
The pulse voltage VM is applied to the data electrode Xj of the column to which ≦ n) belongs. In FIG. 2, the broken line indicates a case where the pixels Z31 and Z41 emit light in addition to the pixel Z11.
At time t2 to t3, the pulse voltage -VH is applied to the scan electrode Y3.
When the pulse voltage VM is applied to the data electrode X1 in synchronization with the application of the voltage VH, the voltage VH + VM is applied to the pixel Z31. Similarly, when the pulse voltage VM is applied to the data electrode X1 in synchronization with the application of the pulse voltage −VH to the scan electrode Y4 from time t3 to t4, the voltage VH + VM is applied to the pixel Z41. Therefore, the pixels Z31, Z41
The EL light-emitting layer 3 belonging to the group emits light.

After the time point t6, voltages having polarities completely opposite to the voltages applied in the field 1 at the time points t0 to t6 are applied to the electrodes X1 to Xn and Y1 to Ym (field 2).
As a result, the pixels Zij that emit light in the field 1 can emit light again, and the charges accumulated in the EL light emitting layer 3 in the field 1 can be released. The EL display device 1 of the present embodiment can display a two-dimensional image by repeating the operations of the field 1 and the field 2.

As described above, in the EL display device 1 according to the present embodiment, voltages having phases opposite to each other can be applied to the EL light emitting layers 3 belonging to the pixels Zlj and Zl-1j in the adjacent row. Then, the vibrations of the EL light-emitting layers 3 at both positions have phases inverted to each other and interfere with each other. For this reason, the vibration of the EL display device 1 as a whole is reduced, and noise can be effectively prevented. Further, in the EL display device 1 according to the present embodiment, noise can be prevented by the operation of the scanning drivers YD1 to YDm without providing a new member such as a spacer, so that the size of the device is not increased.

Further, in the EL display device 1 of the present embodiment, the scan electrodes Yl and Yl-1 for applying voltages of reversed phases are adjacent to each other, and the scan drivers YDl and YDl-1 are connected to the same side of the EL light emitting layer 3. Is provided. That is, the propagation directions of the simultaneously applied pulse voltage VH and pulse voltage -VH are set to be the same direction. It takes a considerable time for the voltage applied by the scan driver YDi to propagate through the scan electrode Yi, as described later. However, with this configuration, the voltages of the EL light emitting layers 3 whose phases are opposite to each other are reduced. The position to which the voltage is applied can be arranged in the immediate vicinity. Therefore, the vibration of the EL light emitting layer 3 at both positions can be made to interfere very well.

In the EL display device 1 of the above embodiment,
A so-called pn target driving method is adopted in which a field 1 and a field 2 are applied with voltages having opposite phases to each other to discharge the electric charges accumulated in the EL light emitting layer 3. A so-called field refresh driving method in which a refresh pulse having a polarity opposite to that of the applied voltage is applied to the device and the electric charge accumulated in the EL light emitting layer 3 is released by the application of the refresh pulse. Further, the scan electrodes Y to which the voltages of the inverted phases are applied need not be adjacent to each other, and for example, a combination of the first row and the third row may be considered. Furthermore,
The scanning driver YD for these scanning electrodes Y may not be provided on the same side. Even with such a configuration, a certain noise prevention effect can be obtained.

In the above embodiment, the pulse voltage -VH as the scanning voltage and the pulse voltage VH as the opposite phase voltage are used.
Have the same absolute value, but the absolute values of the scanning voltage and the antiphase voltage may be different. For example, time points t0 to t in FIG.
At 1, the sum of the voltages applied to the pixels Zij (1 ≦ i ≦ m, 1 ≦ j ≦ n) shifts in the positive direction by the amount of the pulse voltage VM. Therefore, noise may be more properly prevented by slightly increasing the pulse voltage VH as the opposite phase voltage. In this case, the rate at which the pulse voltage VH is increased may be changed according to the number of data electrodes Xj to which the pulse voltage VM is applied. In this case, a further noise prevention effect is obtained.

[0026]

For example, at time points t0 to t1 in FIG.
If a pulse voltage -VM is applied to the data electrode X2, the second
The voltage applied to the pixel Z22 in the second row becomes -VH-VM, and the EL light emitting layer 3 can emit light. In this case, the vibration of the EL light-emitting layer 3 caused by the pulse voltage −VM and the vibration of the EL light-emitting layer 3 caused by the pulse voltage VM applied to the data electrode X1 interfere with each other, so that the noise is further improved. Can be prevented.

FIG. 3 is a time chart showing a second example of a specific operation of the EL display device 1 using both VM and -VM as pulse voltages applied to the data electrodes X1 to Xn. The solid lines in FIG. 3 indicate pixels Z11, Z12, and Z
22 illustrates a case where light is emitted. Further, in this operation example, the applied voltages to the scanning electrodes Y1 to Y4 change in the same manner as in the first operation example, and thus illustration and description are omitted.

In this operation example, as in the first operation example, the pulse voltage VM is applied to the data electrode X1 at time points t0 to t1 and no voltage is applied to the data electrodes X3 to Xn. The following voltage is applied to the electrode X2.
That is, the pulse voltage -VM is applied once each at the time points t0 to t1 and the time points t1 to t2. Thereby, the applied voltage of the pixel Zi2 (1 <i <m) in the second column changes as follows.

At times t0 to t1, the scan electrodes Y1,
The pulse voltages applied to Y2, Y3 to Ym are -VH, VH, and 0, respectively (FIG. 2). Therefore, as shown in FIG. 3, the pulse voltage VH- is applied to the pixel Z12 in the first row and the second column.
VM applies the pulse voltage −V to the pixel Z22 in the second row and second column.
H-VM, and the pixel Zh2 in the third and subsequent rows of the second column
(3 ≦ h ≦ m) is applied with the pulse voltage −VM. Here, since the absolute value of −VH−VM is larger than the threshold value Vth, the pixel Z22 emits light. On the other hand, since the absolute values of VH-VM and -VM are both smaller than threshold value Vth, pixel Z12 and pixels Z32 to Zm2 do not emit light.

At this time, a pulse voltage VM is applied to the pixels Zh1 (3 ≦ h ≦ m) in the third and subsequent rows of the first column as shown in FIG. Therefore, E in pixel Zh1
The vibration of the L light emitting layer 3 and the EL light emitting layer 3 in the pixel Zh2
And the vibrations of the EL display device 1 interfere with each other, so that the noise of the EL display device 1 as a whole can be further reduced.

At the subsequent time points t1 to t2, the data electrode X1
, And no voltage is applied to the data electrode X2.
Apply VM. Accordingly, the pulse voltage -VH-VM is applied to the pixel Z12 in the first row and the second column, and the pixel Z2 in the second row and the second column is used.
2 is a pulse voltage VH-VM, and a pixel Zh2 (3 ≦ h ≦ m) in the third and subsequent rows of the second column is a pulse voltage −VM.
Is applied. Therefore, only the pixel Z12 emits light.
Further, as shown by broken lines in FIG. 3, at time t2 to t3 and at time t3 to t4, the pulse voltage VM is applied to the data electrode X1.
And a pulse voltage -VM applied to the data electrode X2, respectively, when the pixels Z31, Z41, Z32 and the pixel Z
42 emits light.

In the above-described first operation example, the so-called light emission control for controlling whether or not the pixel Zij emits light is performed line by line depending on whether or not a voltage is applied to the data electrode Xj. In the operation example, light emission control is performed in the following pattern. 4 to 6 are explanatory diagrams showing light emission control patterns. 4 to 6, the pixels Zij are partially omitted.

For example, when the column to which the pulse voltage VM is applied in the field 1 and the column to which the pulse voltage −VM is applied in the field 1 are exchanged every other column, the light emission control pattern of the first example shown in FIG. can do. In this case, first, the pixels Zij in the first row and odd columns and the pixels Zij in the second row and even columns are controlled to emit light (a). Subsequently, the pixel Zij of the first row even column and the pixel Zij (b) of the second row odd column, the pixel Zij of the third row odd column and the pixel Zij of the fourth row even column
(C) The pixels Zij on the third row and even column and the pixels Zij (d) on the fourth row and odd column are sequentially controlled to emit light.

When the column to which the pulse voltage VM is applied in the field 1 and the column to which the pulse voltage -VM is applied in the field 1 are switched every two rows, the light emission control pattern of the second example shown in FIG. can do. in this case,
First, the pixels Zij in the first row, first, fourth, fifth and fifth columns and the second row
The light emission of the pixels Zij in the third and sixth columns is controlled (a). Subsequently, the pixels Zij in the first row, the second, third, and sixth columns and the second row
Pixels Zij (b) in the fourth and fifth columns, pixels Zij in the third row, the first, fourth and fifth columns, and pixel Zij in the fourth row and the second, third, and sixth columns
(C) The pixels Zij in the third row, second, third, and sixth columns and the pixels Zij (d) in the fourth row, first, fourth, and fifth columns are sequentially controlled to emit light.

Further, the combination of the scan electrodes Yi to which the pulse voltages having phases inverted to each other are applied is sequentially shifted to the scan electrodes Y1 and Y2, the scan electrodes Y2 and Y3,..., And the pulse voltage VM is changed. If the column to be applied and the column to which the pulse voltage -VM is applied are exchanged every other row, the light emission control pattern of the third example shown in FIG. 6 can be realized. In this case, first, the pixels Zij in the first row and odd columns and the pixels Zij in the second row and even columns are controlled to emit light (a). Subsequently, the pixel Zij of the second row and odd column and the pixel Zij (b) of the third row and even column, the pixel Zij of the third row and odd column and the pixel Zij (c) of the fourth row and even column, and the pixel of the fourth row and odd column Pixel Z
ij and the pixels Zij (d) in the first row and even column are sequentially controlled to emit light. Various other light emission control patterns can be considered.

In the above embodiment, the scanning electrodes Y1 to Ym are directly disposed on one side of the EL light emitting layer 3 so that the EL light emitting layer 3
The data electrodes X1 to Xn are directly arranged on the other surface side of the scan electrodes Y1 to Ym and the data electrodes X1 to Xn.
May be indirectly provided on one side and the other side of the EL light emitting layer 3 via an insulating layer or the like.

As described above, in the EL display device 1 of the above embodiment, the pulse voltage VH and the pulse voltage −VH applied simultaneously are set so that the propagation direction is the same.
The vibrations of the L light emitting layer 3 are made to interfere with each other extremely well. Next, this principle will be described in detail with reference to FIGS.

Scan electrodes Y1 to Ym and data electrode X1
To Xn each have a significant resistance value. For this reason, each scanning driver YDi and its adjacent pixel Zij
Can be considered by replacing the scanning electrode Yi between them with a resistor R1. Similarly, the scanning electrode Yi between the adjacent pixels Zij is connected to the resistor R2, the data electrode Xj between each data driver XDj and the adjacent pixel Zij is connected to the resistor R3, and the data electrode between the adjacent pixels Zij is connected. Xj can be considered by replacing it with the resistor R4. Each pixel Zij can be considered as a kind of capacitor in which the EL electrode 3 is sandwiched between the data electrode Xj and the scanning electrode Yi. Therefore, each pixel Zij is connected to the scanning electrode Y
i connected to the data electrode Xj
j.

Then, the EL display device 1 can be considered by replacing it with a kind of integrating circuit as exemplified in FIG. Therefore, it can be seen that the waveforms of the pixels Z11 and Z21 in FIG. 2 are actually as shown in FIG. That is, the voltage applied to the pixels Z11 and Z21 changes with the same delay time with respect to the application of the rectangular pulse voltage to the scan electrodes Y1 and Y2. In particular, at times t1 to t2 when the pulse voltage VM is not applied to the data electrode X1, the applied voltages of the pixels Z11 and Z21 change completely symmetrically. Therefore, the sum of the voltages applied to the pixels Z11 and Z21 (Z11 + Z21) changes smoothly even at the time points t0 to t1, and is kept at 0 at the time points t1 and t2. This indicates that the vibrations generated at the positions of the pixels Z11 and Z21 in the EL light-emitting layer 3 interfere with each other extremely well.

On the other hand, when the scanning driver YD2 is provided at the end of the scanning electrode Y2 opposite to the scanning driver YD1, the voltage applied to each of the pixels Z11 and Z21 is as shown in FIG.
It changes as illustrated in (B). That is, with this configuration, the delay time of the voltage applied to the pixel Z21 with respect to the application of the voltage to the scan electrode Y2 is longer than the delay time of the voltage applied to the pixel Z11. Therefore, Z11 + Z21 overshoots to the same polarity as the pixel Z11 applied voltage at the start of application of the pulse voltages VH and -VH, and the pulse voltage VH
Immediately after the cutoff of H and -VH, overshoot occurs on the same polarity side as the voltage applied to the pixel Z21. Moreover, this phenomenon occurs at time t
It can be seen from 0 to t1 and from time t1 to t2. Therefore,
In this case, it can be seen that the interference efficiency of vibration of the EL light emitting layer 3 is inferior to that of the above embodiment.

It should be noted that various configurations other than the above-described embodiment can be considered as a configuration in which the propagation directions of the simultaneously applied pulse voltage VH and pulse voltage -VH are the same. For example, as in the EL display device 201 of the second embodiment illustrated in FIG. 9, the scanning electrodes Y1 to Ym are projected from the edge of the EL light emitting layer 3 by changing the projecting direction for each row, and a scanning driver is provided at the tip thereof. Even when YD1 to YDm are connected, each scanning driver YDi may be driven as follows. That is, when the pulse voltage VH is applied to the scan electrode Yi by the scan driver YDi (3 ≦ i ≦ m), at the same time, the scan electrode Yi−
2 may be applied with the pulse voltage -VH. By doing so, the pulse voltages VH, -VH applied simultaneously
Can be made to interfere favorably with the same propagation direction.

The EL of the third embodiment illustrated in FIG.
As in the display device 301, each scanning electrode Yi (1 ≦ i ≦
Scan driver YDi may be connected to both ends of m). Here, it is assumed that a pair of scanning drivers YDi connected to both ends of each scanning electrode Yi simultaneously apply the same pulse voltage as the scanning driver YDi of the first embodiment. In this case, each pulse voltage VH, -VH is propagated from both ends of each scanning electrode Yi toward the center. Therefore, the vibration can be favorably interfered by making the propagation directions of the simultaneously applied pulse voltages VH and -VH the same.

Next, in each of the above embodiments, one pixel Zi
Although one display unit is configured by j, one display unit may be configured by a plurality of pixels. FIG. 11 is a schematic configuration diagram illustrating an EL display device 401 according to the fourth embodiment. As shown in the figure, the EL display device 401 of this embodiment
As in the first embodiment, four scanning electrodes YA1 to YA4, which are arranged in parallel on one side of the EL light emitting layer 3 and to which a pulse voltage is applied by a scanning driver (not shown), and EL
Four data electrodes XA1 to XA4 arranged on the other surface of the light emitting layer 3 in a direction orthogonal to the scanning electrodes YA1 to YA4 and to which a pulse voltage is applied by a data driver (not shown).
A4. Note that the scanning driver and the data driver of the present embodiment were configured similarly to the scanning driver YDi and the data driver XDj of the EL display device 1.
Further, the number of the scanning electrodes YAi and the number of the data electrodes XAj may be any number as long as the number is an even number. Scan electrodes YA1 to YA4 and data electrodes XA1 to XA1
Each intersection with XA4 becomes a pixel SA11 to SA44.
Then, the pixels SA11, SA12, SA21, and S
A22 forms a display unit ZA11. Similarly, the pixels SA (2k-1) (21-1), SA
(2k-1) (2l), SA (2k) (21-1), and SA (2k) (2l), the display unit ZAkl
(K, l = 1, 2, 3, 4).

The EL display device 401 thus configured
Is driven, for example, by applying the following pulse voltage. FIG. 12 is a time chart illustrating a first example of a specific operation of the EL display device 401. In FIG. 12, the solid line represents a case where only the display unit ZA11 emits light. First, from time t0 to time t1, the pulse voltage -VH is applied to the scan electrode YA1 and the pulse voltage VH is applied to the scan electrode YA2. At the same time, a pulse voltage VM is applied to the data electrode XA1, and a pulse voltage −VM is applied to the data electrode XA2.

At this time, when the voltage applied to each pixel SAij is considered as the voltage of the data electrode XAj based on the scanning electrode YAi, the voltage VH + VM is applied to the pixel SA11.
However, the voltage -VH-VM is applied to the pixel SA22. Since the absolute value of each voltage is larger than the threshold value Vth, the EL light emitting layer 3 belonging to the display unit ZA11 emits light. At this time, the voltage VH−VM is applied to the pixel SA12.
However, although the voltage −VH + VM is applied to the pixel SA21, the absolute value of each voltage is smaller than the threshold value Vth. Therefore, the pixels SA12 and SA21 do not contribute to the light emission. Further, at this time, the scanning electrodes YA3, YA4,
Although not shown, no voltage is applied to the data electrodes XA3 and XA4. Therefore, the display units ZA21, ZA
22, ZA12 does not emit light.

Subsequently, at time t1 to t2, the scanning electrode Y
The pulse voltage -VH is applied to A3 and the scan electrode YA
4, a pulse voltage VH is applied. At this time, the data electrode X
Since no voltage is applied to A1 to XA4, none of the display units ZAij emits light. When the display unit ZA21 emits light, the data electrodes XA1, XA2
, And voltages VM and −VM, respectively (illustrated by broken lines in the figure). Then, the absolute value of the voltage applied to the pixels SA31 and SA42 exceeds the threshold value Vth, and the display unit ZA21 emits light. After the time point t6 when the scanning of one screen is completed, a voltage having a polarity completely opposite to the voltage applied in the field 1 at the time points t0 to t6 is applied to discharge the electric charge accumulated in the EL light emitting layer 3 in the field 1. (Field 2).

Here, in this embodiment, the scanning electrodes YA1,
A voltage having the same magnitude and a reversed phase is applied to YA2, and a voltage having the same magnitude and a reversed phase is applied to the data electrodes XA1 and XA2. Therefore, each pixel SA
ij is always 0, and the value of E
The vibration of the L light emitting layer 3 interferes very well. Therefore,
Noise can be prevented very well.

In the above operation example, the pixels SA12, S
A21 does not contribute to the emission of the display unit ZA11. That is, the pixels SA (2k−1) (2l) and SA (2k) (2
l-1) is not used for image display. However, if the following voltage application is performed, EL EL is performed using all the pixels SAij.
An image can be displayed on the light emitting layer 3.

FIG. 13 is a time chart showing a second example of the specific operation of the EL display device 401. In this operation example,
The pulse voltage -VH is applied to the scan electrode YA1 and the pulse voltage VH is applied to the scan electrode YA2 from time t0 to immediately before time t2.
Are continuously applied. Also, the data electrode XA
1 and XA2, the pulse voltages VM and -VM are applied at times t0 to t1 as in the first operation example, and at times t1 to t1.
At t2, pulse voltages -VM and VM are applied, respectively. Then, at time t0 to t1, the pixels SA11, SA22
, A voltage whose absolute value exceeds the threshold value Vth is applied, and at time t1 to t2, the voltage VH + is applied to the pixel SA12.
VM (> Vth) is applied to the pixel SA21 with the voltage −VM−V
M (<−Vth) is applied. For this reason,
In the period from time t1 to t2, the display unit ZA11 emits light by the voltage applied to the pixels SA21 and SA12.

In this case as well, noise can be prevented very well by applying voltages of the same magnitude, the phases of which are inverted, to the scan electrodes YA1, YA2 and the data electrodes XA1, XA2. Further, since all the pixels SAij contribute to light emission, a non-light emitting portion on the screen of the EL display device 401, that is, a so-called non-light emitting portion can be eliminated.

Further, even when the voltage shown in FIG. 12 is applied, the EL display device 5 of the fifth embodiment illustrated in FIG.
When 01 is used, the area of the non-light emitting portion can be reduced. In the EL display device 501 of the present embodiment, the scanning electrode Y
B1 to YB4 are scanning electrodes YA1 to YA1 of the EL display device 401.
YA4 has the same configuration as that of the data electrodes XB1 to XB.
The width of B4 is changed as follows. That is, the pixels SB (2k-1) (21-1), SB contributing to light emission
(2k) and (2l) are scanning electrodes YB (2k-1) and YB
(2k), and conversely, pixels SB (2k−1) (2l) and SB (2) that do not contribute to light emission.
k) (21-1) are scanning electrodes YB (2k-1), YB
It is configured to become smaller along (2k). Therefore, the pixels SB (2k-1) (2l-
1) and SB (2k) (2l) occupy a large proportion on the screen, and the area of the non-light emitting portion can be reduced.

It should be noted that the present invention is not limited to the above embodiment, and can be implemented in various modes without departing from the gist of the present invention.

[0054]

As described above in detail, in the EL display device of the present invention, the EL light emitting layer of the pixel to which the scanning voltage is applied,
It is possible to apply voltages of opposite phases to the EL light emitting layer of the pixel to which the opposite phase voltage is applied. Then
The vibrations of the two EL light emitting layers have phases inverted to each other and interfere with each other. Therefore, according to the present invention, the vibration of the entire EL display device is reduced, and noise can be favorably prevented.
Further, according to the present invention, noise can be prevented by the operation of the scanning voltage applying means without providing a new member such as a spacer, so that the size of the apparatus is not increased.

Furthermore, if the direction in which the scanning voltage propagates through the scanning electrode and the direction in which the anti-phase voltage applied simultaneously with the scanning voltage propagates through the scanning electrode become the same direction, a new The effect of is obtained. That is, E
By arranging the position of the L light emitting layer to which a voltage of the opposite phase is applied closer, the vibration and noise of the EL display device can be further reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an EL display device according to a first embodiment.

FIG. 2 is a time chart illustrating a first example of a specific operation of the EL display device according to the first embodiment.

FIG. 3 is a time chart illustrating a second specific example of the operation of the EL display device according to the first embodiment.

FIG. 4 is an explanatory diagram illustrating a first example of a light emission control pattern in a second example of the specific operation.

FIG. 5 is an explanatory diagram illustrating a second example of a light emission control pattern in a second example of the specific operation.

FIG. 6 is an explanatory diagram illustrating a third example of the light emission control pattern in the second example of the specific operation.

FIG. 7 is an explanatory diagram illustrating an equivalent circuit of the EL display device according to the first embodiment.

FIG. 8 is an explanatory diagram illustrating a change in a pixel applied voltage in consideration of a delay time in the first embodiment.

FIG. 9 is a schematic configuration diagram illustrating an EL display device according to a second embodiment.

FIG. 10 is a schematic configuration diagram illustrating an EL display device according to a third embodiment.

FIG. 11 is a schematic configuration diagram illustrating an EL display device according to a fourth embodiment.

FIG. 12 shows a specific operation of the EL display device according to the fourth embodiment (first example).
It is a time chart showing an example.

FIG. 13 shows a specific operation of the EL display device according to the fourth embodiment.
It is a time chart showing an example.

FIG. 14 is a schematic configuration diagram illustrating an EL display device according to a fifth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... EL display device 3 ... EL light emitting layer X1-X
n: Data electrode XD1 to XDn: Data driver Y1 to Y
m: scanning electrode YD1 to YDm: scanning driver Z11 to
Zmn: Pixel

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-307691 (JP, A) JP-B-51-4813 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) G09G 3/30 G09G 3/20 611 H05B 33/08

Claims (2)

(57) [Claims] 1. An EL light emitting layer that emits light by applying a voltage having an absolute value equal to or higher than a threshold value, a plurality of scanning electrodes arranged in parallel on one side of the EL light emitting layer, A plurality of data electrodes disposed on the surface side in parallel in a direction orthogonal to the scanning electrodes; and an EL display device comprising a pixel at each intersection of the scanning electrodes and the data electrodes. A scanning voltage having an absolute value smaller than the threshold value is sequentially applied to the electrodes, and one of the scanning electrodes to which the scanning voltage is not applied has a phase opposite to the scanning voltage smaller than the threshold value. Scanning voltage applying means for applying an opposite phase voltage to the data electrode, wherein the scanning voltage is an absolute value smaller than the threshold value and larger than a value obtained by subtracting the scanning voltage from the threshold value, to the predetermined data electrode. Reverse polarity data And a data voltage applying means for applying a provided, absolute absolute value of the inverse phase voltages of the data voltage
An EL display device which is larger than a pair value . 2. The apparatus according to claim 2, wherein said scanning voltage applying means is configured such that a propagation direction in which said scanning voltage propagates through said scanning electrode is the same as a propagation direction in which said antiphase voltage applied simultaneously with said scanning voltage propagates through said scanning electrode. 2. The EL display device according to claim 1, wherein the scanning voltage and the antiphase voltage are applied so as to be in the same direction.