JP2018152170A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device capable of suppressing reflection of external light and improving light extraction efficiency from a light emitting element.SOLUTION: A display device according to an embodiment of the present invention includes a plurality of organic light emitting elements arranged in a matrix and a polarizing plate disposed opposite to the plurality of organic light emitting elements and changing transmittance of light according to an electric field.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a display device.

  In an OLED (Organic Light Emitting Diode) display device, an image can be displayed by arranging light emitting elements on a substrate such as glass and controlling the light emitting elements with electrodes (wirings) arranged in a grid pattern.

  In the OLED display device, a metal having high reflectivity is used for the electrodes and wirings, so external light may be reflected by the electrodes and wirings, and the visibility of the image may be deteriorated. Therefore, a technique for preventing reflection of external light using a circularly polarizing plate has been proposed.

  Patent Document 1 describes a circularly polarizing plate in which a polarizer and a quarter wavelength plate are laminated. By providing this circularly polarizing plate on the panel surface, external light is first converted into linearly polarized light by a polarizer and then converted into circularly polarized light by a quarter wavelength plate. The external light (circularly polarized light) reflected in the panel is converted again into linearly polarized light by the quarter wavelength plate and enters the subsequent polarizer. Here, since the phase of the circularly polarized light is inverted upon reflection, the linearly polarized light incident on the polarizer is orthogonal to the transmission axis of the polarizer and is absorbed by the polarizer.

JP 2006-171235 A

  By using the circularly polarizing plate described in Patent Document 1, reflection of external light can be suppressed. However, since part of the emitted light from the light emitting element is also absorbed by the circularly polarizing plate, the luminance of the light extracted outside is reduced.

  In view of the above-described problems, an object of the present invention is to provide a display device capable of suppressing reflection of external light and improving light extraction efficiency from a light emitting element.

  A display device according to an embodiment of the present invention includes a plurality of organic light-emitting elements arranged in a matrix, and a polarization that is disposed to face the plurality of organic light-emitting elements and changes light transmittance according to an electric field. A board.

  ADVANTAGE OF THE INVENTION According to this invention, while suppressing reflection of external light, the display apparatus which can improve the extraction efficiency of the light from a light emitting element is provided.

1 is a block diagram of a display device according to a first embodiment. It is a top view which shows the structure of the OLED panel which concerns on 1st Embodiment. It is sectional drawing which shows the laminated structure of the light emitting element which concerns on 1st Embodiment. It is a top view which shows the electrode structure of the polarizing plate which concerns on 1st Embodiment. It is a cross-sectional schematic diagram of the polarizing plate which concerns on 1st Embodiment. It is a cross-sectional schematic diagram of the polarizing plate which concerns on 1st Embodiment. It is a figure for demonstrating operation | movement of the polarizing plate at the time of light emission which concerns on 1st Embodiment. It is a figure for demonstrating operation | movement of the polarizing plate at the time of the non-light emission which concerns on 1st Embodiment. It is a top view which shows the electrode structure of the polarizing plate which concerns on 2nd Embodiment. It is a cross-sectional schematic diagram which shows the structure of the OLED panel which concerns on other embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a block diagram of a display device according to the present embodiment. The display device includes an OLED panel 10, a polarizing plate 20, a control unit 30, and drive circuits 31 and 32. The OLED panel 10 includes a plurality of light emitting elements 11 as pixels. The light emitting element 11 has a light emitting layer of an organic material and is also called an organic light emitting element or an organic light emitting diode (OLED). The drive circuit 31 includes a gate driver, a data driver, a power supply circuit, and the like, and drives the light emitting element 11 based on a signal from the control unit 30. The drive circuit 31 may be configured integrally with the OLED panel 10.

  The polarizing plate 20 is laminated on the OLED panel 10 and is disposed to face the plurality of light emitting elements 11. The polarizing plate 20 has a function of changing the light transmittance according to the electric field, and is driven by the driving circuit 32. The drive circuit 32 includes a gate driver, a data driver, a power supply circuit, and the like, and supplies a voltage to the polarizing plate 20 based on a signal from the control unit 30.

  The control unit 30 includes a CPU (Central Processing Unit), a memory, an interface, and the like, and transmits a luminance signal, a timing signal, and the like based on the input image signal to the drive circuits 31 and 32. The control unit 30 can control the operations of the OLED panel 10 and the polarizing plate 20 via the drive circuits 31 and 32. The control unit 30 may include an image processing circuit that performs a predetermined correction process on the image signal.

  FIG. 2 is a plan view showing the configuration of the OLED panel 10 according to the present embodiment. The OLED panel 10 includes a light emitting element 11, a pixel circuit 12, a gate line 13g, and a data line 13d, and is driven by an active matrix method. The light emitting element 11 is an element that emits white light, for example, and includes any color filter of R (red), G (green), and B (blue). The plurality of light emitting elements 11 are arranged in a matrix with a predetermined color arrangement pattern.

  The pixel circuit 12 is provided for each light emitting element 11 and includes a switch element, a drive element, a capacitor, and the like. A TFT (Thin Film Transistor) is used for the switch element and the drive element. The gate line 13g extends along one direction of the arrangement of the light emitting elements 11, and the data line 13d extends in a direction orthogonal to the gate line 13g. The light emitting element 11 is connected to the gate line 13g and the data line 13d via the pixel circuit 12 in the vicinity of the intersection of the gate line 13g and the data line 13d.

  The gate line 13g and the data line 13d are connected to the gate driver 31g and the data driver 31d, respectively. The gate driver 31g and the data driver 31d constitute a drive circuit 31. The gate driver 31g sequentially selects the gate lines 13g and applies a gate voltage for turning on the pixel circuit 12. The data driver 31d applies a data voltage corresponding to the luminance signal from the control unit 30 to the data line 13d in synchronization with the gate driver 31g. The pixel circuit 12 in the on state supplies a driving current corresponding to the data voltage to the light emitting element 11 to cause the light emitting element 11 to emit light. The drive current is supplied through a power line (not shown).

  FIG. 3 is a cross-sectional view showing a laminated structure of the light emitting element 11 according to this embodiment. The light emitting element 11 is formed on the panel substrate 15 and has a transparent electrode (anode) 16, a white light emitting layer 17, and a reflective electrode (cathode) 18. A material such as glass or plastic is used for the panel substrate 15, and in addition to the light emitting element 11, a pixel circuit 12, a gate line 13 g, a data line 13 d, and the like can be formed. The OLED panel 10 is a bottom emission type, and the light 100 emitted from the light emitting element 11 is extracted outside through the panel substrate 15. Between the panel substrate 15 and the light emitting element 11, a color filter 19 composed of three primary colors of R (red), G (green), and B (blue) is provided.

  The transparent electrode 16 is made of a conductive material such as ITO (Indium Tin Oxide) and is formed on the panel substrate 15. The light emitting layer 17 is a single layer or a multilayer laminate, and is formed between the transparent electrode 16 and the reflective electrode 18. The light emitting layer 17 is composed of, for example, three layers of a hole transport layer, a light emitting layer, and an electron transport layer. The hole transport layer and the electron transport layer may include a hole injection layer and an electron transport layer, respectively. An organic material such as a trisaluminum complex or a bisberyllium complex can be used for the light-emitting layer. The reflective electrode 18 is made of a metal material such as aluminum or silver, and is formed on the light emitting layer 17. A sealing layer for protecting the light emitting element 11 may be formed on the surface of the reflective electrode 18 opposite to the light emitting layer 17.

  In the light emitting element 11, when voltage is applied to the transparent electrode 16 and the reflective electrode 18, holes and electrons are injected into the light emitting layer 17 from the transparent electrode 16 and the reflective electrode 18, respectively. In the light emitting layer 17, excitons that are hole electron pairs are formed, and the excitons are deactivated to emit light. The light 100 from the light emitting element 11 generated in this way is transmitted through the quarter-wave plate 40 and the polarizing plate 20 laminated on the panel substrate 15 and emitted to the outside.

  The quarter-wave plate 40 gives a phase difference of 90 degrees to the transmitted light, and converts linearly polarized light into circularly polarized light or circularly polarized light into linearly polarized light. For the quarter-wave plate 40, for example, a birefringent material such as polycarbonate or cycloolefin polymer can be used. The quarter wavelength plate 40 may be composed of a plurality of birefringent plates, or may be provided in the polarizing plate 20. The polarizing plate 20 selectively transmits linearly polarized light having a specific vibration direction from non-polarized light such as outside light. The polarizing plate 20 can function as a circularly polarizing plate for reducing external light reflection by combining with the quarter wavelength plate 40.

  Subsequently, the polarizing plate 20 will be described in detail. FIG. 4 is a plan view showing an electrode configuration of the polarizing plate 20 according to the present embodiment. The polarizing plate 20 includes an upper substrate 21a and a lower substrate 21b arranged in parallel, and electrode pairs 22a and 22b are provided on opposing surfaces of the upper substrate 21a and the lower substrate 21b. The electrode pairs 22 a and 22 b are used for generating an electric field in the polarizing plate 20. The electrode 22a is shown in FIG. 4 (a), and the electrode 22b is shown in FIG. 4 (b).

  The electrode 22a is a solid electrode formed on almost the entire surface of the upper substrate 21a, and is used in common for the plurality of electrodes 22b. The electrode 22b is, for example, a rectangular planar electrode, and a plurality of electrodes 22b are formed in a matrix. The plurality of electrodes 22b are provided corresponding to each pixel of the OLED panel 10. For example, the plurality of light emitting elements 11 shown in FIG. 2 and the plurality of electrodes 22b shown in FIG. 4B have the same arrangement pattern and are arranged so as to overlap in plan view.

  In addition to the electrode 22b, the lower substrate 21b is provided with a switch element 23, a gate line 23g, and a data line 23d. The switch element 23 is, for example, a TFT and is provided for each electrode 22b. The gate line 24g extends along one direction of the arrangement of the switch elements 23, and the data line 24d extends perpendicular to the gate line 24g. The electrode 22b is connected to the gate line 24g and the data line 24d via the switch element 23 in the vicinity of the intersection of the gate line 24g and the data line 24d.

  The gate line 24g and the data line 24d are connected to the gate driver 32g and the data driver 32d, respectively. The gate driver 32g and the data driver 32d constitute a drive circuit 32. The gate driver 32g sequentially selects the gate lines 24g and applies a gate voltage for turning on the switch element 23. The data driver 32d applies a voltage corresponding to the luminance signal from the control unit 30 to the data line 24d in synchronization with the gate driver 32g. The switch element 23 in the “on state” supplies the voltage of the data line 24d to the electrode 22b and generates an electric field between the electrode pair 22a and 22b. The electrode 22a is connected to a common potential line (not shown) and is held at a predetermined potential.

  FIG. 5 is a schematic cross-sectional view of the polarizing plate 20 according to the present embodiment, and shows a cross section taken along the line A-A ′ shown in FIGS. 4 (a) and 4 (b). FIG. 5 schematically shows the alignment of the liquid crystal layer 25 when no electric field is generated. The liquid crystal layer 25 is provided between the electrode pairs 22a and 22b, and a transparent conductive material such as ITO is used for the electrode pairs 22a and 22b. The electrode 22a is formed on the upper substrate 21a, and the electrode 22b is formed on the lower substrate 21b. A transparent insulating material such as glass or plastic is used for the upper substrate 21a and the lower substrate 21b.

  The liquid crystal layer 25 includes a low molecular liquid crystal 26 and a dichroic dye 27, and both the low molecular liquid crystal 26 and the dichroic dye 27 have an elongated molecular shape (ellipsoid). The low molecular liquid crystal 26 is uniaxially aligned (homogeneous alignment) in a plane parallel to the upper substrate 21 a and the lower substrate 21 b, and the dichroic dye 27 is aligned along the low molecular liquid crystal 26. For the low-molecular liquid crystal 26, for example, a known material such as 4-cyano-4'-pentylbiphenyl can be used.

  The dichroic dye 27 has the property that the light absorption rate differs depending on the orientation direction. Specifically, the dichroic dye 27 absorbs the polarization component that vibrates in the major axis direction and transmits the polarization component that vibrates in the minor axis direction. As the dichroic dye 27, for example, in addition to iodine, an azo compound such as a disazo compound, a trisazo compound, or a tetrakisazo compound can be used. The concentration of the dichroic dye 27 may be 2.0% by weight or more with respect to the low molecular liquid crystal 26.

  Alignment films 28a and 28b are provided between the electrode 22a and the liquid crystal layer 25, and between the electrode 22b and the liquid crystal layer 25, respectively. The alignment films 28a and 28b are obtained by subjecting a polyimide film to an alignment process such as rubbing or polarized UV (ultraviolet) irradiation, and the low-molecular liquid crystal 26 is aligned in a certain direction defined by the alignment process.

  FIG. 6 is a schematic cross-sectional view of the polarizing plate 20 according to the present embodiment, showing a cross section taken along the line A-A ′ shown in FIGS. 4 (a) and 4 (b). FIG. 6 schematically shows the alignment of the liquid crystal layer 25 when an electric field is generated. The electric field can be generated corresponding to each of the plurality of light emitting elements 11 (pixels), and the direction perpendicular to the direction in which the electrode pair 22a, 22b extends between the electrode pair 22a, 22b to which a voltage is applied. An electric field E is generated.

  The low molecular liquid crystal 26 has a dielectric anisotropy polarized in the major axis direction. When the dielectric anisotropy of the low molecular liquid crystal 26 is positive, the orientation of the low molecular liquid crystal 26 changes in a direction parallel to the electric field E. The degree of orientation, that is, the angle formed by the major axis direction of the low-molecular liquid crystal 26 and the electric field direction (alignment angle) is proportional to the strength of the electric field E. When the orientation angle of the low molecular liquid crystal 26 is changed, the dichroic dye 27 is also aligned along the low molecular liquid crystal 26. Therefore, the orientation angle θ of the dichroic dye 27 can be controlled by the electric field E.

  As the intensity of the electric field E increases, the orientation angle θ of the dichroic dye 27 decreases, and the dichroic dye 27 from the direction of light transmission in the polarizing plate 20, that is, the direction perpendicular to the upper substrate 21 a and the lower substrate 21 b. The apparent length of the long axis is shortened. In other words, the incident angle of light with respect to the long axis direction of the dichroic dye 27 increases as the intensity of the electric field E increases. Therefore, the smaller the orientation angle θ, the smaller the amount of polarization component absorbed by the dichroic dye 27. The transmittance of the liquid crystal layer 25 is maximum when the orientation angle θ of the dichroic dye 27 is 0 degree, and is minimum when it is 90 degrees.

  Next, the operation of the polarizing plate 20 will be described. FIG. 7 is a schematic diagram of the light emitting element 11 and the polarizing plate 20, and shows a cross section of the polarizing plate 20 including the light emitting element 11 and electrode pairs 22 a and 22 b provided corresponding to the light emitting element 11. . When a luminance signal is input from the control unit 30 to the driving circuit 31, the driving circuit 31 applies a voltage corresponding to the luminance signal to the transparent electrode 16 and the reflective electrode 18 of the light emitting element 11 via the pixel circuit 12. As a result, a drive current flows between the transparent electrode 16 and the reflective electrode 18, and light 100 is generated in the light emitting layer 17.

  The light 100 passes through the transparent electrode 16, the color filter 19, and the panel substrate 15 and then enters the quarter wavelength plate 40. Although the polarization state of the light 100 is changed by the quarter-wave plate 40, since the light 100 is non-polarized light that vibrates in various directions, the light 100 transmitted through the quarter-wave plate 40 is also non-polarized light.

  The light 100 transmitted through the quarter-wave plate 40 passes through the lower substrate 21b, the electrode 22b, and the alignment film 28b in order from the polarizing plate 20, and then enters the liquid crystal layer 25. At this time, the control unit 30 controls the polarizing plate 20 so that the transmittance is increased according to the intensity of the light 100 (the emission intensity of the light emitting element 11). For example, the control unit 30 applies a voltage proportional to the luminance signal transmitted to the drive circuit 31 to the electrode pairs 22 a and 22 b via the drive circuit 32. The control unit 30 may apply a voltage to the electrode pairs 22a and 22b only when the luminance signal or the emission intensity based on the luminance signal exceeds a predetermined threshold.

  When a voltage is applied to the electrode pairs 22 a and 22 b, the orientation of the low molecular liquid crystal 26 and the dichroic dye 27 changes in a direction parallel to the traveling direction of the light 100. Thereby, most of the light 100 incident on the liquid crystal layer 25 is transmitted through the liquid crystal layer 25 without being absorbed. The light 100 further passes through the alignment film 28a, the electrode 22a, and the upper substrate 21a in this order and is emitted to the outside.

  FIG. 8 is a schematic view similar to FIG. 7 and shows a cross section of the light emitting element 11 and the polarizing plate 20 when no light is emitted. In FIG. 8, no luminance signal is input from the control unit 30 to the drive circuit 31, or display with a luminance signal of 0 (black display) is performed. No voltage is applied to the transparent electrode 16 and the reflective electrode 18 of the light emitting element 11, and no light 100 is generated in the light emitting layer 17. In such a case, the reflection of the external light 200 by the reflective electrode 18 of the light emitting element 11 may be a problem.

  The external light 200 may include natural light such as sunlight and light from an external device such as a lighting device or a display device. The external light 200 passes through the upper substrate 21a, the electrode 22a, and the alignment film 28a in order, and then enters the liquid crystal layer 25. In the liquid crystal layer 25, the low molecular liquid crystal 26 and the dichroic dye 27 are aligned in a direction perpendicular to the traveling direction of the external light 200. For this reason, the polarization component of the external light 200 that vibrates in the long axis direction of the dichroic dye 27 is absorbed by the dichroic dye 27, and the external light 200 transmitted through the liquid crystal layer 25 is short of the dichroic dye 27. The linearly polarized light vibrates in the axial direction.

  The linearly polarized external light 200 passes through the alignment film 28b, the electrode 22b, and the lower substrate 21b in this order, and enters the quarter-wave plate 40. The linearly polarized external light 200 is converted into circularly polarized light by the quarter-wave plate 40, and is sequentially transmitted through the panel substrate 15, the color filter 19, the transparent electrode 16, and the light emitting layer 17 and reflected by the reflective electrode 18. The external light 200 after reflection becomes circularly polarized light having a rotation direction different from that before reflection, passes through the light emitting layer 17, the transparent electrode 16, the color filter 19, and the panel substrate 15 in order, and enters the quarter wavelength plate 40 again.

  The reflected external light 200 is converted into linearly polarized light by the quarter-wave plate 40, passes through the lower substrate 21 b, the electrode 22 b, and the alignment film 28 b in order and enters the liquid crystal layer 25 again. Here, the polarization direction of the external light 200 after reflection incident on the liquid crystal layer 25 is orthogonal to the polarization direction of the external light 200 before reflection reflected from the liquid crystal layer 25. That is, the external light 200 incident on the liquid crystal layer 25 is linearly polarized light that vibrates in the major axis direction of the dichroic dye 27. Therefore, most of the reflected external light 200 is absorbed by the dichroic dye 27 in the liquid crystal layer 25. Even when the light emitting element 11 emits light (see FIG. 7), the reflection of the external light 200 can occur. In the case where the light emission intensity of the light emitting element 11 is relatively small and easily affected by the reflection of the external light 200, the transmittance of the liquid crystal layer 25 may be reduced even during light emission, and the reflected light may be absorbed by the liquid crystal layer 25 .

  As described above, the display device of this embodiment includes the OLED panel 10 having the plurality of light emitting elements 11 arranged in a matrix and the polarizing plate 20 that changes the light transmittance according to the electric field. Yes. The polarizing plate 20 is provided on the surface of the OLED panel 10 and transmits light from the light emitting element 11. When the light emitting element 11 is not emitting light, the reflection of the external light can be suppressed by reducing the transmittance of the polarizing plate 20. On the other hand, when the light emitting element 11 emits light, by improving the transmittance of the polarizing plate 20, light from the light emitting element 11 can be efficiently extracted outside the display device. Therefore, it is possible to improve the luminance of the displayed image while maintaining a good luminance level in black display, and thus it is possible to display an image with high contrast.

  Furthermore, since the light extraction efficiency from the light emitting element 11 is improved, even if the drive current amount of the light emitting element 11 is reduced, an image can be displayed with a luminance equivalent to that of a conventional display device. Therefore, it is possible to reduce power consumption, reduce the load on the light emitting element 11, and extend the life of the light emitting element 11.

[Second Embodiment]
Next, a display device according to the second embodiment will be described. Since the display device of the present embodiment is configured in the same manner as the display device of the first embodiment, a description will be given focusing on a configuration different from the first embodiment.

  FIG. 9 is a plan view showing an electrode configuration of the polarizing plate 20 according to the present embodiment. The polarizing plate 20 includes an upper substrate 21a and a lower substrate 21b arranged in parallel, and electrode pairs 22a and 22b are provided on opposing surfaces of the upper substrate 21a and the lower substrate 21b. The electrode 22a is shown in FIG. 9 (a), and the electrode 22b is shown in FIG. 9 (b).

  The electrodes 22a are formed in stripes in the row direction (X direction) on the upper substrate 21a. The electrodes 22b are orthogonal to the electrodes 22a and are formed in stripes in the column direction (Y direction) on the lower substrate 21b. A region (intersection region) where the electrode 22a and the electrode 22b intersect in plan view corresponds to each pixel of the OLED panel 10. That is, the electrode pairs 22a and 22b are formed so that the intersecting region overlaps with the plurality of light emitting elements 11 shown in FIG.

  The electrodes 22a and 22b are connected to a row driver 32a and a column driver 32b, respectively. The row driver 32 a and the column driver 32 b constitute a drive circuit 32. The row driver 32a selects a row to which a voltage is applied based on a signal from the control unit 30, and applies a voltage corresponding to the luminance signal to the electrode 22a of the selected row. Similarly, the column driver 32b selects a column to which a voltage is applied based on a signal from the control unit 30, and applies a voltage according to the luminance signal to the electrode 22b of the selected column. An electric field is generated in the intersecting region of the electrodes 22a and 22b to which a voltage is applied, and the transmittance can be controlled for each pixel by this electric field.

[Other Embodiments]
The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention. For example, as shown in FIG. 10, the OLED panel 10 may be configured by three types of light emitting layers 17 that emit light in RGB colors instead of the white light emitting layer 17. Accordingly, the color filter 19 is removed. Further, in the above-described embodiment, the transmittance of the polarizing plate 20 is configured to be controllable in units of pixels of the OLED panel 10, but the transmittance of the polarizing plate 20 is controlled in units of pixel blocks including a plurality of pixels or the entire panel. It may be configured to control. By configuring the electrodes 22a and 22b of the polarizing plate 20 with solid electrodes, the structure can be simplified.

  Further, the liquid crystal layer 25 is not limited to the one whose orientation is changed by an electric field, and may be one whose orientation is directly changed by light from the light emitting element 11. For example, the liquid crystal layer 25 can be configured using an element whose molecular shape is deformed by absorbing light, an element that generates a nonlinear optical effect, or the like. Furthermore, the polarizing plate 20 of the present embodiment is not limited to one that adjusts light according to an electric field, and may include a configuration that changes the alignment state of the liquid crystal layer 25 according to an external field such as a magnetic field, temperature, or light.

  The OLED panel 10 of this embodiment should just have the light emitting layer 17 which can light-emit independently. That is, the polarizing plate 20 of the present embodiment is applicable to a top emission type OLED panel. Further, the polarizing plate 20 of the present embodiment is not limited to an OLED panel, but can be applied to a display panel using an inorganic LED (light emitting diode), a reflective LCD (Liquid Crystal Display) panel, or the like.

DESCRIPTION OF SYMBOLS 10 OLED panel 11 Light emitting element 12 Pixel circuit 15 Panel substrate 16 Transparent electrode 17 Light emitting layer 18 Reflective electrode 19 Color filter 20 Polarizing plate 21a Upper substrate 21b Lower substrate 22a, 22b Electrode (pair)
25 Liquid crystal layer 26 Low molecular liquid crystal 27 Dichroic dye 30 Control unit 31, 32 Drive circuit 40 1/4 polarizing plate

Claims (11)

A plurality of organic light emitting devices arranged in a matrix;
A display device comprising: a polarizing plate that is disposed to face the plurality of organic light emitting elements and changes light transmittance according to an electric field.   The polarizing plate includes an electrode pair for generating the electric field and a liquid crystal layer provided between the electrode pair, and the liquid crystal layer has a light absorption rate that varies depending on an orientation direction. The display device according to claim 1, comprising:   The liquid crystal layer includes a uniaxially aligned low-molecular liquid crystal, the dichroic dye is aligned along the low-molecular liquid crystal, and the alignment direction is controlled by applying a voltage to the electrode pair. 2. The display device according to 2.   The display device according to claim 3, wherein the liquid crystal layer transmits linearly polarized light orthogonal to the alignment direction.   5. The display device according to claim 2, wherein the electrode pair is provided corresponding to each of the plurality of organic light emitting elements, and generates the electric field according to the light emission intensity of the organic light emitting element. .   The display device according to claim 5, wherein the electrode pair generates the electric field when the corresponding organic light emitting element emits light, and does not generate the electric field when the corresponding organic light emitting element does not emit light.   The display device according to claim 5, wherein the electrode pair is provided in a matrix so as to overlap with the corresponding organic light emitting element in plan view.   One of the electrode pairs is provided in a stripe shape corresponding to the arrangement in the first direction of the plurality of organic light emitting elements, and the other of the electrode pairs corresponds to the arrangement in the second direction orthogonal to the first direction. The display device according to claim 5, wherein the display device is provided in a stripe shape.   5. The display device according to claim 2, wherein the electrode pair is a solid electrode provided on the entire opposing surface of the substrate of the polarizing plate. 6.   The display device according to claim 2, further comprising a control unit that controls a voltage applied to the electrode pair based on a voltage applied to the organic light emitting element.   11. The display device according to claim 1, further comprising a ¼ wavelength plate that is provided between the plurality of organic light emitting elements and the polarizing plate and gives a phase difference of 90 degrees to transmitted light. .

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