JP2001034221A - Driving circuit of organic electroluminescence element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve display quality by making light emitting intensity more uniform and conducting adjustment in accordance with secular change. SOLUTION: The driving circuit is provided with at least an anode 12 which is made of a transparent and electrically conductive material on a transparent substrate, an organic layer which consists of one or more layers and a cathode 14 (14a and 14b) made of a metallic electrically conductive material opposing the anode 12. The anode 12 is divided and formed into plural segments 12a to 12f in accordance with the shape to be displayed and one terminal of the cathode 14 is made into common with 14a and 14b. The former is made into groups by serially connecting the number of segments that does not exceed N where N is an integer of greater than 1 and each group is connected to a first driving control circuit 20. The latter is divided and formed into N parts and each is connected to a second driving control circuit 30. The first driving control circuit 20 has a PWM circuit 23 (23A1 and 23A2 to 23D1 and 23D2) and a switching circuit 24 (24A1 and 24A2 to 24D1 and 24D2), that selects the segments 12a to 12f to each of which current is supplied, and is connected to a constant current power supply circuit 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a driving circuit for an organic electroluminescence element.

[0002]

2. Description of the Related Art Indium tin oxide (IT) is formed on a transparent substrate.
O), an anode made of a transparent conductive material such as O, an organic layer composed of one or more layers (at least a single layer structure of an organic light emitting layer,
Alternatively, at least a cathode made of a metal conductive material such as aluminum (Al) or a multilayer structure in which any one of a hole injection layer, a hole transport layer, an electron transport layer, and the like is laminated together with an organic light emitting layer from the anode side. An organic electroluminescent element having the same is disclosed in, for example, Japanese Patent Publication No. 6-32307.

[0003] Such an organic electroluminescence element is capable of emitting light in a predetermined pattern depending on the shape of the anode and the cathode, and a DC voltage of several volts to several tens of volts is applied between the anode and the cathode. Accordingly, light emission from the organic layer according to the pattern can be seen through the transparent substrate, and has an advantage that low voltage driving is possible as compared with a thin film type or dispersion type electroluminescent element.

By the way, one of the anode and the cathode is divided and formed as a plurality of display pixel electrodes (segments) corresponding to the display shape, and the other is used as a common electrode (common) by connecting a power source between the two electrodes. A so-called segment type organic electroluminescence element that selectively emits light is
For example, it is disclosed in Japanese Patent Application Laid-Open No. 9-106887 and has an advantage that a desired display shape can be easily obtained.

[0005] However, in such an organic electroluminescence element, although a common requires only one wiring for connection to an external drive circuit, a segment requires wiring electrodes by the number of segments. In the configuration in which the numbers “0” to “9” are displayed using the segments, seven connection wires are required for the segments, and 6
In order to display a digit number, 42 connecting wires must be formed.

[0006] Regarding a drive circuit which can solve such a problem, the applicant of the present invention has disclosed in Japanese Patent Application No. 11-151327.
No. (May 31, 1999) and No. 176045 (June 22, 1999), one of the anode or the cathode is divided into a plurality of segments corresponding to the shape to be displayed, and the other is made common. The former is grouped by connecting N (N is an integer of 2 or more) or less segments in series, and each group is connected to a driving circuit, and the latter is divided into N and formed into driving circuits. (Hereinafter referred to as “prior application”).

[0007]

In an organic electroluminescent device, the light emission intensity at a segment is proportional to the current density, and thus differs depending on the area of the segment. In the prior application, in a group in which a plurality of segments are connected, the same group is formed so as not to cause a large difference in luminance between a point in one segment and a point in another segment. For the segment, adjust the voltage applied to each group by selecting one with no significant difference in the area difference, or by connecting adjustment resistors in series with each group and adjusting the values of these resistors. The brightness was uniform among the groups.

However, in an actual design, the areas of the segments hardly become the same, and the variation in luminance cannot be completely eliminated. Further, since the light emission intensity decreases with time (aging), it is also desired to improve this. The present invention is an improvement of the prior application focusing on such a problem, and an object of the present invention is to improve the display quality by making the emission intensity more uniform and adjusting according to aging. It is an object of the present invention to provide an element driving circuit.

[0009]

According to a first aspect of the present invention, there is provided a driving circuit for an organic electroluminescence device, comprising: an anode made of a transparent conductive material on a transparent substrate; An organic electroluminescent element capable of emitting light in a predetermined pattern by having at least a cathode made of a metal conductive material so as to face the layer and the anode, and according to a shape for displaying one of the anode or the cathode. The former is divided into a plurality of segments and the other is made common, and the former is grouped by connecting N (N is an integer of 2 or more) or less segments in series, and each group is a first drive control circuit. And the latter is divided into N parts, each of which is connected to the second drive control circuit, and the first drive control circuit equalizes the current density of the segment. A switching circuit current value determined by the PWM circuit and the PWM circuit for reduction to select the segments to be supplied, and is for connecting the constant current source circuit. In particular, the first drive control circuit includes a conversion circuit for adjusting and setting the duty ratio of the PWM from outside (Claim 3), and the constant current power supply circuit is configured to control a current value. A constant current setting circuit for setting a plurality of levels and a switching circuit for switching and controlling the constant current setting circuit are provided (claim 4).

According to a second aspect of the present invention, there is provided at least an anode made of a transparent conductive material on a transparent substrate, an organic layer composed of one or more layers, and a cathode made of a metal conductive material opposed to the anode. An organic electroluminescent element capable of emitting light in a predetermined pattern by having one of the anode and the cathode divided into a plurality of segments corresponding to a shape for displaying one and the other as a common, and the other is an N (N is an integer of 2 or more) or less segments are connected in series to form a group, and each group is connected to the first drive control circuit, and the latter is divided into N and formed into the second drive control circuit. Of the N drive circuits and the second drive control circuit, wherein the first drive control circuit makes the current density of the segment uniform. In conjunction with the switching operation for selecting the Mont a switch circuit for switching said PWM circuit, said first drive control circuit is used to connect the constant current source circuit. In particular, the first drive control circuit includes a conversion circuit for adjusting and setting the duty ratio of the PWM from outside (Claim 3), and the constant current power supply circuit is configured to control a current value. A constant current setting circuit for setting a plurality of levels and a switching circuit for switching and controlling the constant current setting circuit are provided (claim 4).

According to a fifth aspect of the present invention, there is provided at least an anode made of a transparent conductive material on a transparent substrate, an organic layer composed of one or more layers, and a cathode made of a metal conductive material opposed to the anode. An organic electroluminescent element capable of emitting light in a predetermined pattern by having one or more of the anode or the cathode divided into a plurality of segments having unequal areas according to a display shape and displaying the other. The segment is connected to a drive control circuit that performs static drive for making the current density of the segment uniform by PWM control of the current from the constant current power supply circuit. In particular, the drive control circuit includes a conversion circuit for adjusting and setting the duty ratio of the PWM from outside (Claim 6). The constant current power supply circuit includes a constant current source and a constant current source. A constant current setting circuit for setting a current value sent from the constant current source to a plurality of levels, and a switching circuit for switching and controlling the constant current setting circuit are provided (claim 7).

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the invention described in claim 1,
A predetermined pattern can be emitted by having at least an anode 12 made of a transparent conductive material, an organic layer 13 composed of one or more layers, and a cathode 14 made of a metal conductive material facing the anode 12 on a transparent substrate 11. The organic electroluminescent element 10 is formed by dividing the anode 12 into a plurality of segments 12a to 12f corresponding to the display shape and using the cathode 14 as commons 14a and 14b. The former is N (N is 2 or more). (Integer) or less segments 12a to 12f are connected in series to form a group, and each group is connected to the first drive control circuit 20. The latter is divided into N and formed into the second drive control circuit 20, respectively. PWM connected to the control circuit 30 so that the first drive control circuit 20 equalizes the current densities of the segments 12a to 12f.
A circuit 23 and a switching circuit 24 for selecting the segments 12a to 12f to which a current of a value determined by the PWM circuit 23 is supplied, and by connecting to the constant current power supply circuit 40, the area difference between the segments 12a to 12f Irrespective of the above, the current density of each of the segments 12a to 12f can be made uniform.

According to the second aspect of the present invention, the anode 12 made of a transparent conductive material, the organic layer 13 composed of one or more layers, and the metal An organic electroluminescent device 10 capable of emitting light in a predetermined pattern by having at least a cathode 14 made of a material, wherein an anode 12 is divided into a plurality of segments 12a to 12f corresponding to a display shape and a cathode 14 is formed. Are common 14a, 14b, and the former is grouped by connecting N or less (N is an integer of 2 or more) segments 12a to 12f in series, and each group is connected to the first drive control circuit 20. The latter is divided into N parts, each of which is connected to the second drive control circuit 30, and the first drive control circuit 20 is connected to the segments 12a to 12f. Common 1 of the N PWM circuit 23 and the second drive control circuit 30 for equalizing the flow density
A switching circuit 24 for switching the PWM circuit 23 in conjunction with a switching operation for selecting the switching circuits 4a and 14b. When the first drive control circuit 20 is connected to the constant current power supply circuit 40, the area difference between the segments 12a to 12f is increased. Irrespective of the above, the current density of each of the segments 12a to 12f can be made uniform.

In particular, according to the third aspect of the present invention, in the first or second aspect, the first drive control circuit 20
Has a conversion circuit 25 for externally adjusting and setting the duty ratio of the PWM, so that the current density of each of the segment segments 12a to 12f can be easily adjusted.

According to a fourth aspect of the present invention, in the first or second aspect, the constant current power supply circuit 40 is
A constant current setting circuit 41a for setting a current value to a plurality of levels,
By having the switching circuit 41b and the switching circuit 42 for switching the constant current setting circuits 41a and 41b, the current density of each of the segments 12a to 12f can be changed at a uniform rate.

According to the fifth aspect of the present invention, an anode 12 made of a transparent conductive material, an organic layer 13 composed of one or more layers, and a metal conductive material are provided so as to face the anode 12 on the transparent substrate 10. An organic electroluminescent element 10 capable of emitting light in a predetermined pattern by having at least a cathode 14 made of a material, wherein a plurality of segments 12a to 12f having unequal areas according to the shape in which the anode 12 is displayed are formed. The current is supplied from the constant current power supply circuit 40 to the segments 12a to 12f by PWM control.
By connecting the drive control circuit 20 for performing static driving for equalizing the current densities of the segments 12a to 12f, the current densities of the segments 12a to 12f can be uniform regardless of the area difference between the segments 12a to 12f. .

In particular, according to the sixth aspect of the present invention, in the fifth aspect, the drive control circuit 20 includes the PWM
Has a conversion circuit 25 for adjusting and setting the duty ratio from the outside, the current density of each of the segment segments 12a to 12f can be easily adjusted.

According to a seventh aspect of the present invention, in the fifth aspect, the constant current power supply circuit 40 includes constant current setting circuits 41a and 41b for setting a current value to a plurality of levels, and the constant current setting circuit. By having the switching circuit 42 for switching control of the segments 41a and 41b, the current density of each of the segments 12a to 12f can be changed at a uniform rate.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the embodiments shown in the accompanying drawings.

As shown in FIG. 1, an organic electroluminescent element 10 has an anode 12 made of a transparent conductive material such as ITO on a transparent substrate 11, and an organic layer 13 composed of at least one layer (at least an organic light emitting layer). Or a multilayer structure in which any one of a hole injection layer, a hole transport layer and an electron transport layer is laminated with an organic light emitting layer from the anode side) and a cathode made of a metal conductive material such as Al 14 at least.

The organic electroluminescent device 10
The first and second drive control circuits 20 and 30 as drive circuits are connected to the anode 12 and the cathode 14, respectively. A constant current power supply circuit 40 is connected to the drive control circuits 20 and 30.

Such an organic electroluminescent device 1
Numeral 0 indicates that light can be emitted in a predetermined pattern by the shape of the anode 12 and the cathode 14, which will be described later.
By preparing a power supply of several volts to several tens of volts between the light emitting device 4 and the light emitting device 4, light emission from the organic layer 13 can be seen through the transparent substrate 11.

In this embodiment, the anode 12 is divided into a plurality of segments, and the cathode 14 is selectively made to emit light as a common common, so that a so-called segment type display capable of displaying, for example, the numbers "0" to "9" is provided. The organic electroluminescence element 10 of FIG. Specifically,
As shown in FIG. 2, the anode 12 is configured in a sun-shape composed of a total of seven segments including six segments 12 a to 12 f sequentially located clockwise from the top and one segment 12 g located at the center. Segment 12a, 1
2g (group A), segments 12b and 12c (group B), segments 12d (group C), and segments 12e and 12f (group D).
Each D is connected to the first drive control circuit 20 via a connection wiring. In FIG. 2, seven segments 12
a to 12f form one day character, and this is 6
Although the anodes 12 are arranged side by side, only those located at the right end are grouped, but it goes without saying that other electrical connections are made in the same manner.

As shown in FIG. 3, the cathode 14 has two commons 14a and 14
b, and is connected to the second drive control circuit 30 for each common. The same common 14
In a (14b), the shape of the anode 12 is set so that the segments 12a to 12f constituting the same group do not face each other.

FIG. 4 is an electric circuit diagram of a driving circuit of the organic electroluminescence element 10, in which each display pixel corresponding to the segments 12a to 12f is displayed as a diode. The luminescence element 10 is so-called dynamically driven.

Each of the groups A to D is connected to one terminal of the current mirror circuit 22 via the segment drive control units 21A to 21D constituting the first drive control circuit 20, and the other terminal of the current mirror circuit 22 is connected. Is connected to the constant current power supply circuit 40.

The segment drive control section 21A in the group A comprises a circuit in which a series circuit of a PWM (pulse width modulation) circuit 23A1 and a switch circuit 24A1 and a series circuit of a PWM circuit 23A2 and a switch circuit 24A2 are connected in parallel. The switch circuits 24A1 and 24A2 control only one of the PWM circuits 23A1 and 23A2 to be connected to one of the segments 12a and 12g. For example, the PWM circuit 23A1 controls the segment 1
2a, and the segment 12b is driven by the PWM circuit 23A2.
Switch circuits 24A1 and 24A2 perform on / off switching so as to drive. That is, the first drive control circuit 20 performs constant current drive by PWM control on the segments 12a to 12f.

The operation of the segment drive control unit 21A in the group A is the same as that of the segment drive control units 21B to 21D in the groups B to D. However, although only one segment 12d is connected to the group C, the segment drive control unit 21C is also connected to the segment drive control unit 21A from the viewpoint of sharing circuit components.
It has the same configuration as. In the following description,
PWM circuits 23A1, 23B1, 23C1, 23D1,
When the whole of 23A2, 23B2, 23C2, 23D2 is represented, the PWM circuit 23 and the switch circuits 24A1, 24
B1,24C1,24D1,24A2,24B2,24
When the entirety of C2 and 24D2 is represented, the switch circuit 24
Display as

The commons 14a and 14b are switches 3 which are turned on / off at predetermined timings under the control of a timing circuit 31 constituting the second drive control circuit 30.
2a, 32b are connected to the ground, and the second drive control circuit 30 is connected to the commons 14a, 14
b, for example, when the switch 32a is on, the switch 32b is off, and conversely, the switch 32b
Is turned on, the switch 32a is turned off. In the former case, the segments 12a and 12a facing the common 14a are turned off.
b, 12d, and PWM circuit 23A1, which drives 12e
The switch circuits 24A1, 24B1 and 24C1, 24D1 are turned on so that the 3B1, 23C1, 23D1 operates. In the latter case, the PWM circuit 23A drives the segments 12g, 12c, 12f facing the common 14b.
Switch circuits 24A2, 24B2, (24C2) 24D so that 2,23B2, (23C2), 23D2 operate.
2 is turned on, and these on / off switching is controlled by a timing circuit 31.

Therefore, when displaying the numeral "1", the segment drive control section 2 of the first drive control circuit 20 operates so that the segments 12b and 12c emit light.
All switches of the drive circuits other than 1B are turned off. When displaying the number “2”, the segment 12
When the switch 32a of the second drive control circuit 30 is turned on, the segment drive control units 21A, 21B, 21C of the first drive control circuit 20 are turned on so that the portions a, 12b, 12d, 12e, and 12g emit light. , 21D switch circuit 2
4A1, 24B1, 24C1, 24D1 are turned on,
When the switch 32b is on, the first drive control circuit 20
Switch circuit 24A2 of segment drive control unit 21A
Turns on. The same applies to the case where the numbers “3” to “9” are displayed, and a specific description thereof is omitted. Thus, the organic electroluminescence element 10 is dynamically driven by the drive control circuits 20 and 30 as described above. .

The first and second drive control circuits 20, 3
0 so that the organic electroluminescence element 10 performs a desired display.
21D PWM circuits 23A1, 23A2, 23B1,
A conversion circuit 2 including a decoder for setting and adjusting the duty ratio of the 3B2, 23C1, 23C2, 23D1, and 23D2 from the outside (the frequency may be changed at the same time), and a timing circuit 31 for setting the timing.
The conversion circuit 25 is controlled by an input signal from a control means 50 such as an 8-bit microcomputer, and the control means 50 controls the contents of the display performed by the organic electroluminescence element 10. For example, a sensor means 60 such as a time measurement sensor is connected in the case of displaying the time, and a distance sensor is connected in the case of displaying the traveling distance of the vehicle.

From the above, if the value of the current input to the first drive control circuit 20 is constant, the value of the current output from the first drive control circuit 20 is adjusted by adjusting the conversion circuit 25. Can be set to a desired value. The first drive control circuit 20 performs PWM control on the segments 12 a to 12 f by using a PWM circuit 23 and a switch circuit 24.
Performs constant current drive by control.

The luminous intensity at the segments 12a to 12g is proportional to the current density of the supplied current, and therefore differs depending on the area of the segments 12a to 12g. Therefore, the PWM circuits 23A1, 23A2, 23B
1,23B2,23C1, (23C2) 23D1,2
In 3D2, a duty ratio and a frequency corresponding to the area of the segments 12a to 12g are set in advance, and the segments 12a to 12g are set according to the duty ratio and the frequency.
Is supplied with a constant current described later.

The constant current power supply circuit 40 includes constant current setting circuits 41a and 41b for setting a current value to a plurality of levels, for example, two levels, that is, a normal state and a dimming state.
And a switching circuit 42 for performing switching control of 1a and 41b. For example, when the organic electroluminescent element 10 is used as a display device for a vehicle, the constant current setting circuit 41a is used during traveling in a bright environment such as during the day, so that the constant current power supply circuit 40 has an I1 ampere. A constant current setting circuit 41 is output by a switching circuit 42 which outputs a current and detects a lighting operation of a light switch (not shown) by a driver during traveling in an environment where the surroundings are dark such as at night.
b, the constant current power supply circuit 40 switches to I2 (<I
1) Output amperage current. As a result, the current flowing to the first drive control circuit 20 changes uniformly at a constant rate, so that the current flowing at the locations of the segments 12a to 12g also changes uniformly at a constant rate. There is no variation in the emission intensity according to
The display quality can be improved. Moreover, the segment drive control units 21A to 21A of the first drive control circuit 20
There is no need to individually adjust 21D, and control is easy.

Segments 12a to 12 according to aging
If the light emission intensity at the point g is lower than the initial value, the constant current setting circuits 41a and 41b are adjusted to increase the current value to be sent, thereby increasing the segment 12a.
It is possible to make the light emission intensity at the position of １２12 g close to the initial state, and to improve the display quality. Moreover, there is no need to individually adjust the segment drive control units 21A to 21D of the first drive control circuit 20, and control is easy.

The anode 12 is connected in series with no more than two segments, and the cathode 14 is connected to two commons 14a, 1
4b, and is divided into one by the drive control circuits 20 and 30.
Although the configuration for dynamic drive of / 2 duty has been described, the present invention is not limited to this, and the anode 12 is connected in series with N (N is an integer of 2 or more) segments and the cathode 14 is divided into N commons. Then, it may be configured to drive at 1 / N duty. As the number N increases, the number of the groups decreases and the number of connection wirings decreases, thereby providing an advantage that the area of the segments 12a to 12f used for display can be increased. However, there are disadvantages such as the occurrence of a defect such as generation of an organic electroluminescent element, and the necessity that a series circuit of a PWM circuit and a switch circuit of the segment drive control units 21A to 21D is required for each N sets. N = 2 to 4 are optimal conditions for the element 10 to achieve a balanced display operation.

In the above embodiment, the anode 12 is a segment and the cathode 14 is a common. However, the anode 12 may be a common and the cathode 14 may be a segment.

Further, in the above-described embodiment, the configuration in which the first drive control circuit 20 dynamically drives the motor with a half duty has been described. For example, the description will be given using the reference numerals used in the above-described embodiment. An organic electroluminescent device capable of emitting light in a predetermined pattern by having at least an anode 12 made of a transparent conductive material, an organic layer 13 made of one or more layers, and a cathode 14 made of a metal conductive material facing the anode 12. In the luminescent element 10, one of the anode 12 and the cathode 14 is divided into a plurality of segments each having an unequal area according to the display shape, and the other is a single common. The current from the constant current power supply circuit 40 equalized in each of the segments by the PWM control is statically driven. Be configured to connect the supply drive control circuit 20, similarly to the foregoing embodiment, the current density in each of the segments can be made uniform, it is possible to realize the same operation as the Example.

[0039]

As described above, according to the present invention, regardless of the area of the segment, the drive of the organic electroluminescence element can improve the display quality by making the emission intensity more uniform and adjusting according to aging. A circuit can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a plan view showing a configuration of a segment of the embodiment.

FIG. 3 is a plan view showing a configuration of a common of the embodiment.

FIG. 4 is a circuit diagram illustrating a driving method in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Organic electroluminescent element 12 Anode 12a-12f Segment 14 Cathode 14a, 14b common 20 1st drive control circuit (drive control circuit) 23 PWM circuit 24 switch circuit 25 conversion circuit 30 2nd drive control circuit 40 constant current power supply Circuits 41a, 41b Constant current setting circuit 42 Switching circuit

Claims (7)

[Claims] 1. A light emitting device having a predetermined pattern by having at least an anode made of a transparent conductive material on a transparent substrate, an organic layer composed of one or more layers, and a cathode made of a metal conductive material facing the anode. A possible organic electroluminescent element, wherein one of the anode or the cathode is divided into a plurality of segments according to a display shape and the other is a common, and the former is N (N is an integer of 2 or more). By connecting the segments of the number equal to or less than the number of groups and connecting them in series, each group is connected to the first drive control circuit, and the latter is divided into N and each is connected to the second drive control circuit, PWM for the first drive control circuit to equalize the current density of the segment
A driving circuit for an organic electroluminescent element, comprising: a circuit; and a switching circuit for selecting the segment to which a current having a value determined by the PWM circuit is supplied, and connected to a constant current power supply circuit. 2. A light emission in a predetermined pattern by having at least an anode made of a transparent conductive material on a transparent substrate, an organic layer composed of one or more layers, and a cathode made of a metal conductive material facing the anode. A possible organic electroluminescent element, wherein one of the anode or the cathode is divided into a plurality of segments according to a display shape and the other is a common, and the former is N (N is an integer of 2 or more). By connecting the segments of the number equal to or less than the number of groups and connecting them in series, each group is connected to the first drive control circuit, and the latter is divided into N and each is connected to the second drive control circuit, The first drive control circuit is connected to the N PWM circuits for equalizing the current densities of the segments and the switching operation for selecting the common of the second drive control circuit. A driving circuit for switching the PWM circuit by operating the first driving control circuit, wherein the first driving control circuit is connected to a constant current power supply circuit. 3. The PWM control circuit according to claim 1, wherein the first drive control circuit includes the PWM.
3. The driving circuit for an organic electroluminescent element according to claim 1, further comprising a conversion circuit for adjusting and setting the duty ratio of the organic electroluminescence element from outside. 4. The constant current power supply circuit includes a constant current setting circuit for setting a current value to a plurality of levels, and a switching circuit for switching and controlling the constant current setting circuit. Item 3. A driving circuit for an organic electroluminescence element according to item 2. 5. A light emission in a predetermined pattern by having at least an anode made of a transparent conductive material on a transparent substrate, an organic layer composed of one or more layers, and a cathode made of a metal conductive material facing the anode. A possible organic electroluminescent element, wherein one of the anode and the cathode is divided into a plurality of segments having an unequal area in accordance with a shape to be displayed, and the other is defined as a common segment, and the other segment is defined as a common segment. A drive circuit for an organic electroluminescence element, wherein a drive control circuit for performing static drive for equalizing the current density of the segments by PWM control of a current from a current power supply circuit is connected. 6. The driving circuit according to claim 5, wherein the driving control circuit includes a conversion circuit for externally adjusting and setting the duty ratio of the PWM. 7. The constant current power supply circuit according to claim 5, further comprising: a constant current setting circuit for setting a current value to a plurality of levels; and a switching circuit for switching and controlling the constant current setting circuit. Organic electroluminescence element driving circuit.