JP2018156888A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device capable of switching display of a single organic EL element to a plurality of different displays without overlapping a plurality of organic EL elements.SOLUTION: A display device 1 includes a first electrode 3 including a combination of a plurality of first divided electrodes 3a arranged on a substrate 2 and a plurality of second divided electrodes 3b arranged adjacently to every other one of the plurality of first divided electrodes 3a, a second electrode 4 provided so as to face the first electrode 3, an organic light emitting layer 5 provided between the first electrode 3 and the second electrode 4, and a control unit 13 that controls currents to be supplied respectively to the plurality of first divided electrodes 3a and the plurality of second divided electrodes 3b to switch the light emission display of the organic light emitting layer 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a display device, and more particularly to a display device that can switch a display displayed by a single organic EL element.

  An organic electroluminescence (organic EL) element generally has a structure in which an anode, an organic light emitting material, and a cathode are sequentially laminated on a substrate. An organic EL element is a device that emits light from a light-emitting material with luminance corresponding to the amount of applied current by applying a direct current between an anode and a cathode.

  As an example of a display device using such a device, an organic EL device in which a first EL element and a translucent second EL element formed on the light extraction side of the first EL element are integrated is proposed. (For example, refer to Patent Document 1).

  In the organic EL device described in Patent Document 1, the first EL element has a first organic layer that emits light in the first emission band. The second EL element has a translucent second organic layer that emits light in a second emission band different from the first emission band of the first organic layer of the first EL element. According to Patent Document 1 described above, it is possible to perform toning by changing the luminance for each of the first and second EL elements, and to stabilize the color of the emitted color.

International Publication No. 2013/168210

  By the way, it is possible to switch and display a plurality of different displays by superimposing a plurality of transparent organic EL elements on the front and back. However, since the display of the rear organic EL element needs to be transmitted through the front organic EL element, the luminance (transmittance) decreases due to the influence of the presence or absence of electrodes in the front organic EL element. And uneven brightness. As a result, there is a problem that display quality (appearance) is deteriorated due to luminance reduction or luminance unevenness.

  Accordingly, an object of the present invention is to provide a display device that can switch the display of a single organic EL element to a plurality of different displays without overlapping the plurality of organic EL elements.

  In order to achieve the above object, a display device according to the present invention includes a plurality of first divided electrodes arranged on a substrate, and arranged adjacent to at least every other one of the plurality of first divided electrodes. A first electrode composed of a combination of a plurality of second divided electrodes, a second electrode provided opposite to the first electrode, and an organic light emission provided between the first electrode and the second electrode And a control unit that controls a current flowing through each of the plurality of first divided electrodes and the plurality of second divided electrodes and switches the light emission display of the organic light emitting layer.

  In the display device according to the present invention, the first display unit that emits light from the organic light emitting layer by combining regions corresponding to the plurality of first divided electrodes, and the region corresponding to the plurality of second divided electrodes are combined. A second display unit that emits light from the organic light emitting layer, and the control unit switches to the first display unit or the second display unit for display.

  In the display device according to the present invention, the control unit causes a light emission current to flow through one of the plurality of first divided electrodes and the plurality of second divided electrodes, and causes a bias current to flow through the other electrode. It is characterized by switching to a state.

  According to the present invention, a plurality of different displays can be switched and displayed on a single organic EL element without overlapping the plurality of organic EL elements.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram for demonstrating an example of the internal structure of the display apparatus which concerns on embodiment of this invention, Comprising: (a) is a partially cutaway upper surface schematic diagram, (b) is the 1B-1B line | wire of (a). It is a cross-sectional schematic diagram of an arrow. It is a schematic diagram for demonstrating the wiring structure and display control of an electrode. It is a wave form diagram showing typically the relation of light emission current and bias current to light emission time. It is an image figure of a 1st display, Comprising: (a) is an example of the pattern formed in a light emission area | region, (b) is an example of the visual recognition state of a pattern. It is an image figure of a 2nd display, Comprising: (a) is an example of the pattern formed in a light emission area | region, (b) is an example of the visual recognition state of a pattern.

  Embodiments of a display device according to the present invention will be described below with reference to the accompanying drawings. In the drawings according to the embodiments, the aspect ratio and the like are exaggerated for easy explanation of the configuration.

(Configuration of display device)
1 (a) and 1 (b), a display device 1 provided with a single organic EL element 8 is arranged in a row on a transparent first base material 2 and the first base material 2 at equal intervals. A first electrode 3 composed of a pair of comb-shaped electrodes, a second electrode 4 provided to face the pair of comb-shaped first electrodes 3, and a pair of comb-shaped first electrodes The organic light emitting layer 5 provided between the electrode 3 and the second electrode 4, the insulating layer 6 provided between the first base material 2 and the organic light emitting layer 5, and the second adhesive layer 7 through the transparent adhesive layer 7. It has a transparent second base material 2 bonded to the electrode 4.

  As the organic EL element 8, a transparent organic EL element constituted by laminating a transparent first electrode 3, a transparent second electrode 4, a transparent organic light emitting layer 5, and a transparent insulating layer 6 is used. Is used. As the adhesive layer 7, it is preferable to use an adhesive that does not contain moisture.

  In the illustrated example, the first electrode 3 functions as an anode of the organic EL element. The second electrode 4 functions as a cathode. Any known conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) can be used without particular limitation as the electrode material for forming the anode and the cathode.

  As shown in FIG. 1A, FIG. 1B, and FIG. 2, the first electrode 3 includes three first divided electrodes 3a that are formed in a comb-teeth shape and the same number of first divided electrodes 3a. A pair of comb-like electrodes is formed by combining the second divided electrode 3b formed in a comb-like shape.

  The first divided electrode 3a and the second divided electrode 3b are formed in a strip shape with a necessary width and length. The width of the first divided electrode 3a and the second divided electrode 3b is preferably on the order of about several tens of μm, which is difficult to visually recognize when the organic EL element 8 is not emitting light. The interval formed between the first divided electrode 3a and the second divided electrode 3b is preferably set to a minute interval of about 10 μm that cannot be visually recognized.

  The second electrode 4 is a flat common electrode common to the first electrode 3, and is formed on the entire surface of the organic light emitting layer 5.

  For the organic light emitting layer 5, any known organic light emitting material can be used without particular limitation. By using organic light emitting materials having different emission colors for the organic light emitting layer 5, different emission colors can be emitted. By setting it as the structure which has several functional layers, such as a positive hole transport layer and an electron carrying layer, on both sides of the organic light emitting layer 5, the luminous efficiency by the organic light emitting layer 5 can be increased.

  For the insulating layer 6, any known insulating material can be used without particular limitation. Since the gap between each of the first divided electrode 3a and the second divided electrode 3b is set to a minute interval dimension of about 10 μm, the insulating layer 6 is a material that can be finely processed to a minimum width of about 10 μm. It is preferable that

  In the insulating layer 6, an opening 6 a that exposes the first electrode 3 is formed. The opening 6a is processed by the organic light emitting layer 5 into a shape for displaying a display pattern such as letters, numbers, figures and symbols.

  A region where the insulating layer 6 does not exist between the first electrode 3 and the organic light emitting layer 5 due to the opening 6 a of the insulating layer 6 enables electrical connection between the first electrode 3 and the second electrode 4. Yes. Thereby, the opening 6a of the insulating layer 6 constitutes a light emitting region 5a capable of emitting light that the organic light emitting layer 5 is desired to emit.

  The region where the insulating layer 6 formed so as to overlap between the first electrode 3 and the organic light emitting layer 5 is electrically insulated between the first electrode 3 and the second electrode 4. 5 constitutes a non-light emitting region 5b through which no current can flow. Note that the insulating layer 6 is not necessarily provided when the light emitting region 5a has the same shape as the electrode.

  Each of the 1st and 2nd base materials 2 and 2 is a core material film as a base material which has optical transparency and flexibility. By providing a light-transmitting barrier layer on the core film, it is preferable to configure it as a barrier film for blocking oxygen, moisture and the like in the outside air. Any known material can be used without particular limitation for the core material film and the barrier layer.

(Configuration of display unit and display switching control unit)
As shown in FIGS. 1A, 1B, and 2, the first electrode 3 configured as a pair of comb-like electrodes is electrically divided into two groups independently. ing. In the illustrated example, the three first divided electrodes 3a and the same number of second divided electrodes 3b as the first divided electrodes 3a are electrically independent from each other. With this configuration, the combination of applying current can be changed.

  The light emitting region 5a obtained by combining the corresponding regions with the three first divided electrodes 3a is configured as a first display unit 9 that causes the organic light emitting layer 5 to emit light. The first display unit 9 emits and displays a display pattern such as letters, numbers, figures, symbols, and the like by a combination of the organic light emitting layer 5 and the first divided electrode 3a. In the illustrated example, a rectangular display form appears in the top view by the opening 6 a of the insulating layer 6.

  On the other hand, the light emitting region 5 a obtained by combining the regions corresponding to the three second divided electrodes 3 b is configured as the second display unit 10 that emits light from the organic light emitting layer 5. The second display unit 10 is on the same plane as the first display unit 10, and displays a display pattern of characters, numbers, figures, symbols, and the like by a combination of the organic light emitting layer 5 and the second divided electrode 3 b. . In the illustrated example, a circular display form appears in a top view by the opening 6 a of the insulating layer 6.

  In the configuration of the first and second display portions 9 and 10, the common first electrode wiring 11 that supplies current to the organic light emitting layer 5 through the three first divided electrodes 3a and the three second divided portions. The common 2nd electrode wiring 12 which supplies an electric current to the organic light emitting layer 5 via the electrode 3b is provided.

  By sharing electrode wiring and connectors for each of the three first divided electrodes 3a and the three second divided electrodes 3b, an increase in the number of electrode wirings and the number of connectors can be suppressed. Can be realized. In addition, as electrode wiring, it is preferable to have transparency and translucency similarly to an electrode.

  Each of the first and second divided electrodes 3a and 3b is electrically connected to the control unit 13 that switches the display of the organic EL element 8 through the first and second electrode wirings 11 and 12.

  The control unit 13 provided in the display device 1 employs a microcomputer including components such as a CPU, a ROM, and a RAM. When the CPU executes the control program stored in the ROM, the currents flowing to the three first divided electrodes 3a and the three second divided electrodes 3b through the first electrode wiring 11 and the second electrode wiring 12 are controlled. The As a configuration for executing the control program, various methods, components, and the like can be employed.

  A current necessary for light-emitting display of the organic EL element 8 is caused to flow from the control unit 13 to the three first divided electrodes 3a via the first electrode wiring 11, whereby the first display unit corresponding to the first divided electrodes 3a. The display state in which only 9 is displayed by light emission and the current necessary for the light emission display of the organic EL element 8 are allowed to flow from the control unit 13 to the three second divided electrodes 3b via the second electrode wiring 12, thereby the second It is possible to switch to the display state in which only the second display unit 10 corresponding to the divided electrode 3b is displayed with light emission.

3, the control unit 13, three and one state passing a light emission current I ₁ to the divided electrodes of one of the first divided electrode 3a and three second divided electrode 3b, the bias to the other divided electrode It switched between a state in which electric current I _2.

Since these first divided electrode 3a and the second divided electrode 3b are adjacent, non-application time of the bias current I ₂ is a counter electromotive force is generated in the electrode side of the light emission current I ₁ is not applied with the electromagnetic induction phenomenon However, there is a possibility of causing element destruction. Therefore, it is preferable to use a driving method in which a bias current I ₂ (a non-light-emission weak current amount) equal to or lower than the threshold current is applied to the non-light-emitting electrode side.

  By applying a direct current between the three first divided electrodes 3a and the second electrode 4, or between the three second divided electrodes 3b and the second electrode 4, the organic light emitting layer 5 has three holes. While being injected from the first divided electrode 3 a or the three second divided electrodes 3 b, electrons are injected from the second electrode 4.

  The organic light emission in the organic light emitting layer 5 is caused by the energy generated when the holes injected from the first divided electrode 3a or the second divided electrode 3b and the electrons injected from the second electrode 4 are recombined in the organic light emitting layer 5. The material is excited. When the excited organic light emitting material returns to the ground state, the organic light emitting layer 5 emits light in a shape representing the opening 6 a of the insulating layer 6.

  Referring to FIG. 4A and FIG. 5A, these drawings show examples of the first display pattern of the first display unit 9 and the second display pattern of the second display unit 10, respectively. . The distance D between the light emitting regions 5a corresponding to the three first divided electrodes 3a in the first display unit 9 and the distance D between the light emitting regions 5a corresponding to the three second divided electrodes 3b in the second display unit 10 are actually larger. Also shown enlarged.

  As shown in FIG. 1A, FIG. 1B, and FIG. 4A, the first electrode 3 has a minute width that is difficult to visually recognize, and the three first divided electrodes in the first display unit 9 The three first divided electrodes 3a can be recognized as one light emitting region 5a in combination with the minute distance D that is difficult to visually recognize between the respective electrodes 3a.

  As shown in FIG. 4 (b), the shape of the first display pattern, which is a quadrilateral shape that is connected without the gap D between the three first divided electrodes 3a and the corresponding light-emitting regions 5a, is formed. Visible.

  As shown in FIGS. 1 (a), 1 (b), and 5 (a), even if it is between the respective electrodes of the three second divided electrodes 3b in the second display unit 10, it is invisible. Since the distance is D, the three second divided electrodes 3b can be recognized as one light emitting region 5a.

  As shown in FIG. 5 (b), similarly to the first display pattern shown in FIG. 4 (b), the circular shape that is the second display pattern appears to correspond to the three second divided electrodes 3b. It is visually recognized as one shape that is connected without the interval D.

  Note that by reducing the distance D formed between each of the plurality of first divided electrodes 3a and the plurality of second divided electrodes 3b, it becomes possible to reduce the unevenness of the transmittance, and the display device 1 The luminance unevenness of the light transmitted through each of the constituent members can be reduced.

  According to the illustrated example, three first divided electrodes 3a arranged in a line on the first base material 2 and three first divided electrodes 3a arranged adjacent to every other one of the three first divided electrodes 3a. Although it is configured as a pair of comb-shaped first electrodes 3 composed of a combination with the two-divided electrode 3b, it is not particularly limited thereto.

  Arbitrary plural first divided electrodes 3a arranged on the first substrate 2 as an example, and plural plural arbitrary arranged adjacent to at least every other one of plural plural first divided electrodes 3a Even with the configuration of a pair of comb-shaped first electrodes 3 composed of a combination with the second divided electrode 3b, the initial object of the present invention can be achieved.

  In the illustrated example, a pair of comb-shaped first electrodes 3 is illustrated, but the present invention is not particularly limited thereto. As the configuration of the first electrode 3, it can be configured as two or three or more pairs of comb-shaped first electrodes 3 as long as it can cope with the way of electrode wiring, the position of display, the shape and size, etc. Of course.

(Effect of embodiment)
According to the display device 1 configured as described above, a plurality of comb-shaped first electrodes 3 each composed of a combination of a plurality of first divided electrodes 3a and a plurality of second divided electrodes 3b are configured. Since the current flowing through each of the first and second divided electrodes 3a and 3b is switched, the following effects can be obtained in addition to the above effects.

  A plurality of types of display patterns can be switched and displayed on the same surface or the same location in a single organic EL element 8.

  The display device 1 can be configured to display a plurality of types of display on the same surface or the same location of a single organic EL element 8 without switching a plurality of organic EL element devices back and forth. Therefore, it is possible to reduce luminance reduction and luminance unevenness without being affected by the presence or absence of electrodes in the front organic EL device.

  It is possible to suppress a decrease in display quality caused by a decrease in luminance or luminance unevenness.

  The display device 1 can be made compact and thin.

  The light-emitting light emitted from the organic light-emitting layer 5 may be a flexible single-sided light emitting display device 1 that can extract light emitted from the second electrode 4 side to the outside. It can also be configured as a flexible double-sided light emitting display device 1 that can be taken out from both sides of the third and second electrodes 4.

  Of course, the display device 1 configured as described above can be applied to various devices for in-vehicle use, portable use, and home use.

  As is clear from the above description, typical embodiments, modifications, and illustrations according to the present invention have been illustrated. However, the above-described embodiments, modifications, and illustrations relate to the claims. The invention is not limited. Therefore, it should be noted that not all the combinations of features described in the above embodiments, modifications, and illustrated examples are necessarily essential to the means for solving the problems of the invention.

DESCRIPTION OF SYMBOLS 1 ... Display apparatus, 2 ... 1st base material and 2nd base material, 3 ... 1st electrode, 3a ... 1st divided electrode, 3b ... 2nd divided electrode, 4 ... 2nd electrode, 5 ... Organic light emitting layer, 5a DESCRIPTION OF SYMBOLS ... Light emitting area, 5b ... Non-light emitting area, 6 ... Insulating layer, 6a ... Opening part, 7 ... Adhesive layer, 8 ... Organic EL element, 9 ... 1st display part, 10 ... 2nd display part, 11 ... 1st electrode Wiring, 12 ... second electrode wiring, 13 ... control unit, D ... interval, I ₁ ... light emission current, I ₂ ... bias current

Claims (3)

A first electrode comprising a combination of a plurality of first divided electrodes arranged on a substrate and a plurality of second divided electrodes arranged adjacent to at least every other one of the plurality of first divided electrodes; ,
A second electrode provided facing the first electrode;
An organic light emitting layer provided between the first electrode and the second electrode;
A control unit that controls currents that flow through each of the plurality of first divided electrodes and the plurality of second divided electrodes, and switches the light emitting display of the organic light emitting layer;
A display device comprising: A first display unit that emits light from the organic light emitting layer by combining regions corresponding to the plurality of first divided electrodes, and a second display that emits light from the organic light emitting layer by combining regions corresponding to the plurality of second divided electrodes. A display unit,
The display device according to claim 1, wherein the display is switched to the first display unit or the second display unit by the control unit.   The control unit switches between a state in which a light emission current flows through one of the plurality of first divided electrodes and the plurality of second divided electrodes and a state in which a bias current flows through the other electrode. The display device according to claim 1 or 2.

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