KR102369825B1 - Display Device - Google Patents

Abstract

An object of the present invention is to provide a display device capable of improving image quality in a bright environment.
A display device includes: a light emitting element; a pixel including a quantum dot layer that converts a wavelength of light generated from the light emitting element; It has a light-reducing film.

Description

Display Device {Display Device}

The present invention relates to a display device.

In Patent Document 1, a display device using a blue organic light-emitting diode (OLED) as a light emitting element and a quantum dot layer as a light conversion layer for converting the wavelength of light emitted from the OLED has been developed. There is (Patent Document 1).

Patent Document 1: Korean Patent Publication No. 10-2017-0096583

When a quantum dot layer is used as the light conversion layer, when external light is incident on the quantum dot layer and hits the quantum dots in the quantum dot layer, the quantum dots are excited and emit light. The direction and polarization properties of light from the emitted quantum dots were changed from that of incident external light. Therefore, even if the antireflection film is formed on the display surface, it is difficult to block the light emitted from the quantum dots emitted by external light from being emitted from the display surface. For this reason, the image quality deteriorates, especially in a bright environment.

SUMMARY OF THE INVENTION An object of the present invention is to provide a display device capable of improving image quality in a bright environment in view of the above problems.

According to one aspect of the present invention, a light emitting device and a device including a quantum dot layer for converting a wavelength of light generated from the light emitting device, and the quantum dot layer is formed on the opposite side to the light emitting device, the quantum dot layer There is provided a display device comprising a light-reducing film for reducing external light incident on the display device.

According to the present invention, image quality can be improved in a bright environment.

1 is a block diagram showing a schematic configuration of a display device according to a first embodiment of the present invention.
FIG. 2 is a diagram showing an example of arrangement of pixels and sub-pixels in a panel of the display device according to the first embodiment of the present invention.
3 is a circuit diagram showing a schematic configuration of a sub-pixel of the display device according to the first embodiment of the present invention.
4 is a cross-sectional view showing a schematic configuration of a pixel of the display device according to the first embodiment of the present invention.
5 is a schematic diagram showing light emission of a pixel of the display device according to the first embodiment of the present invention.
6 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a modification of the first embodiment of the present invention.
7 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a second embodiment of the present invention.
8 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a modification of the second embodiment of the present invention.
9 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a third embodiment of the present invention.
10 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a modification of the third embodiment of the present invention.
11 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a fourth embodiment of the present invention.
12 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a modification of the fourth embodiment of the present invention.
13 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a fifth embodiment of the present invention.
14 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a modification of the fifth embodiment of the present invention.
15 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a sixth embodiment of the present invention.
16 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a modification of the sixth embodiment of the present invention.

<First embodiment>

A display device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 5 .

First, a schematic configuration of the display device according to the present embodiment will be described with reference to FIGS. 1 to 3 . 1 is a block diagram showing a schematic configuration of a display device according to the present embodiment. 2 is a diagram showing an example of arrangement of pixels and sub-pixels in a panel of the display device according to the present embodiment. 3 is a circuit diagram showing a schematic configuration of a sub-pixel of the display device according to the present embodiment.

The display device according to the present embodiment uses an organic light emitting diode (OLED) as a light emitting element in a pixel, and displays an image based on input RGB data. The use of the display device according to the present embodiment may be, for example, a computer image output device, a television receiver, a smartphone, a game machine, or the like, but is not particularly limited.

As shown in FIG. 1 , the display device includes a timing controller TCON 1 , a panel 2 , a plurality of source drive ICs SDIC 3 , and a plurality of gate drive ICs GDIC 4 . The panel 2 includes a plurality of pixels arranged in a matrix, and functions as a display unit for displaying an image.

The timing controller 1 is communicatively connected to the plurality of source drive ICs 3 and the plurality of gate drive ICs 4 . The timing controller 1 includes a plurality of source drive ICs 3 and a plurality of gate drive ICs 4 based on timing signals (vertical synchronization signal, horizontal synchronization signal, data enable signal, etc.) input from an external system. control the timing of the operation.

As will be described later, the pixels in the panel 2 include sub-pixels of red (R), green (G), and blue (B) colors. The timing controller 1 generates RGB data representing the luminance of each sub-pixel of the panel 2 based on RGB data that is an input signal input from an external system, and converts the RGB data to a plurality of source drive ICs 3 . output as an output signal to Note that the number of source drive ICs 3 and gate drive ICs 4 is not limited to those shown.

Each of the plurality of source drive ICs 3 supplies voltages (video signals) for driving a plurality of pixels in the panel 2 through a plurality of data lines under the control of the timing controller 1 . Each of the plurality of gate drive ICs 4 supplies a scan signal to a plurality of pixels in the panel 2 through a plurality of gate lines under the control of the timing controller 1 . In this way, the timing controller 1 functions as a display control device that controls the operation of the entire display device.

FIG. 2 is an arrangement diagram of the pixels Pixel 20 and subpixels 21R, 21G, and 21B in the panel 2 . The panel 2 includes a plurality of pixels 20 arranged to form a plurality of rows and a plurality of columns. Each of the plurality of pixels 20 includes a sub-pixel 21R emitting red light, a sub-pixel 21G emitting green light, and a sub-pixel 21B emitting blue light. Hereinafter, when there is no need to distinguish colors of the sub-pixels 21R, 21G, and 21B, it is simply referred to as 'sub-pixel 21'.

The sub-pixels 21R, 21G, and 21B are arranged side by side in a predetermined direction in the pixel 20 as shown in FIG. 2 , for example.

The luminance of the sub-pixels 21R, 21G, and 21B is controlled according to the voltage output from the source drive IC 3 . When the sub-pixels 21R, 21G, and 21B emit light with a predetermined luminance ratio, the pixel 20 can display various colors by additive color mixing.

As described above, the display device of the present embodiment has a pixel configuration corresponding to RGB three-color display.

In addition, in this specification, one of red and green may be called a 1st color, blue may be called a 2nd color, and the other of red and green may be called a 3rd color. In addition, in this specification, one of the red subpixel and the green subpixel may be referred to as a first subpixel, the blue subpixel may be referred to as a second subpixel, and the other of the red subpixel and green subpixel may be referred to as a third subpixel.

Moreover, in this embodiment, the quantum dot layer of each color as a light conversion layer is formed suitably in a sub-pixel. The quantum dot layer of each color functions as a wavelength conversion layer for emitting light of each color by converting the wavelength of the incident light emitted from the OLED. Specifically, for example, the red quantum dot layer converts blue light emitted from the blue OLED to emit red light. The green quantum dot layer converts blue light emitted from the blue OLED to emit green light. The quantum dot layer is constituted of a layer such as a resin in which quantum dots are dispersed, for example, made of a semiconductor material having a particle size, material, or the like corresponding to the output wavelength.

3 shows a schematic configuration of the sub-pixel 21 . In FIG. 3 , a subpixel 21 included in any one pixel 20 among a plurality of pixels 20 , a source drive IC 3 connected to the subpixel 21 , and the subpixel One gate drive IC 4 connected to 21 is shown.

The sub-pixel 21 includes a scan transistor M1 , a driving transistor M2 , and a diode D . The diode D is a light emitting element of a display device, and is an OLED. The scan transistor M1 and the driving transistor M2 are, for example, thin film transistors (TFT). In the present embodiment, it is assumed that the scan transistor M1 and the drive transistor M2 are of an n-channel type. However, the scan transistor M1 and the driving transistor M2 may be of a p-channel type. Also, when the driving transistor M2 is a p-channel type, the circuit configuration of the sub-pixel 21 may be different from that shown in FIG. 3 .

The cathode of the diode D is connected to a potential line that supplies the potential VSS. The anode of the diode D is connected to the source of the driving transistor M2. A drain of the driving transistor M2 is connected to a potential line that supplies a potential VDD. The gate of the driving transistor M2 is connected to the source of the scan transistor M1.

A data line DL is connected to the drain of the scan transistor M1. The source drive IC 3 supplies an image signal to the drain of the scan transistor M1 through the data line DL. A gate line GL is connected to the gate of the scan transistor M1. The gate drive IC 4 supplies a control signal to the gate of the scan transistor M1 through the gate line GL. The scan transistor M1 is turned on or off according to the level of the control signal input to the gate.

The current flowing between the drain and source of the driving transistor M2 is a voltage (video signal) input from the source driver IC 3 to the gate of the driving transistor M2 through the data line DL and the scan transistor M1. controlled based on A current flowing between the drain and source of the driving transistor M2 is supplied to the diode D, and the diode D emits light with a luminance corresponding to the current. In this way, the diode D emits light with a luminance corresponding to the video signal input to the sub-pixel 21 .

Next, the pixel 20 of the display device according to the present embodiment will be further described with reference to FIGS. 4 and 5 . 4 is a cross-sectional view showing a schematic configuration of a pixel 20 of the display device according to the present embodiment. 5 is a schematic diagram showing light emission of the pixel 20 of the display device according to the present embodiment.

As shown in FIG. 4 , each pixel 20 in the panel 2 includes a red sub-pixel 21R, a green sub-pixel 21G, and a blue sub-pixel 21B.

The panel 2 includes an element substrate 100 and a color filter substrate 200 . The color filter substrate 200 is disposed so as to face the element formation surface of the element substrate 100 . The display device according to the present embodiment is a top light emission type in which light is emitted from the element formation surface side of the glass substrate 30 of the element substrate 100 . That is, in the display device according to the present embodiment, the element formation surface side of the glass substrate 30 in the element substrate 100 is the display surface side.

The element substrate 100 has a glass substrate 30 which is a transparent substrate, and the blue OLED 32 which is a light emitting element which radiates blue light. In the following, the case of using the glass substrate 30 and the glass substrates 40, 50, and 60 described later as the substrate of the panel 2 will be described as an example. A transparent substrate may be used.

In each pixel 20 , on the element formation surface of the glass substrate 30 , three anode electrodes 34 made of metal electrodes are formed so as to correspond to the sub-pixels 21R, 21G, and 21B. The anode electrode 34 has sufficient reflectance and is configured as a reflective electrode functioning also as a reflective layer. On each anode electrode 34 , a blue organic light emitting layer 36 made of an organic light emitting material emitting blue light is formed. On each blue organic light-emitting layer 36 , a common cathode electrode 38 made of a transparent electrode is formed.

As described above, in each pixel 20 , an OLED 32 having an anode electrode 34 , a blue organic light emitting layer 36 , and a cathode electrode 38 is formed for each of the sub-pixels 21R, 21G, and 21B. . A sealing film (not shown) or the like is formed on the entire surface of the glass substrate 30 on which the cathode electrode 38 is formed.

On the other hand, the color filter substrate 200 includes a glass substrate 40 which is a transparent substrate, color filters 42R and 42G, quantum dot layers 44R and 44G, a semi-transmissive film 46 , and an anti-reflection film 48 . there is. The antireflection film 48 includes a quarter wave plate 481 and a polarizing plate 482 .

A red color filter 42R is formed on the surface of the glass substrate 40 facing the element substrate 100 so as to face the OLED 32 of the red subpixel 21R. The color filter 42R is formed on the glass substrate 40 through the semi-transmissive film 41 . The semi-transmissive film 41 is formed with a predetermined film thickness so as to transmit visible light with a predetermined transmittance. Although the semi-transmissive film 41 is not specifically limited, For example, it is a metal film, such as an aluminum film. A red quantum dot layer 44R is formed on the surface of the color filter 42R facing the element substrate 100 . The red quantum dot layer 44R functions as a light conversion layer that converts the wavelength of light, and converts the wavelength of the blue light emitted from the OLED 32 to emit red light. Light emitted from the quantum dot layer 44R includes unconverted blue light together with red light.

As described above, the red sub-pixel 21R including the blue OLED 32 , the red quantum dot layer 44R and the red color filter 42R is configured. In the subpixel 21R having the quantum dot layer 44R, the color filter 42R on the display surface side of the panel 2 with respect to the quantum dot layer 44R, which is the entry side of external light with respect to the quantum dot layer 44R. A semi-transmissive film 41 is formed between the and the glass substrate 40 . That is, the semi-transmissive film 41 is formed on the opposite side to the OLED 32 with respect to the quantum dot layer 44R, and is formed on the opposite side to the quantum dot layer 44R with respect to the color filter 42R.

Moreover, on the surface of the glass substrate 40 opposite to the element substrate 100, the green color filter 42G is formed so that it may oppose the OLED 32 of the green sub-pixel 21G. The color filter 42G is formed in the glass substrate 40 through the semi-transmissive film 41 similarly to the color filter 42R. A green quantum dot layer 44G is formed on the surface of the color filter 42G facing the element substrate 100 . The green quantum dot layer 44G functions as a light conversion layer that converts the wavelength of light, and converts the wavelength of the blue light emitted from the OLED 32 to emit green light. Light emitted from the quantum dot layer 44G includes unconverted blue light together with green light.

As described above, the green sub-pixel 21G including the blue OLED 32 , the green quantum dot layer 44G and the green color filter 42G is configured. In the subpixel 21G having the quantum dot layer 44G, the color filter 42G on the display surface side of the panel 2 with respect to the quantum dot layer 44R, which is the entry side of external light with respect to the quantum dot layer 44G. A semi-transmissive film 41 is formed between the and the glass substrate 40 . That is, the semi-transmissive film 41 is formed on the opposite side to the OLED 32 with respect to the quantum dot layer 44G, and is formed on the opposite side to the quantum dot layer 44G with respect to the color filter 42G.

On the other hand, neither a color filter nor a quantum dot layer is formed on the surface of the glass substrate 40 opposite to the element substrate 100 so as to face the OLED 32 of the blue sub-pixel 21B. Therefore, the blue sub-pixel 21B includes the blue OLED 32 , but does not include a blue color filter, other color filters, or a quantum dot layer. That is, the sub-pixel 21B emits blue light without passing through the blue color filter or other color filters.

Also in the blue sub-pixel 21B not having a quantum dot layer, the semi-transmissive film 41 may be formed on the glass substrate 40, but from the viewpoint of ensuring luminance, the semi-transmissive film 41 is provided in the sub-pixel 21B. It is preferable that this is not formed.

In addition, a sealing film (not shown) or the like is formed on the entire surface of the glass substrate 40 on which the color filters 42R and 42G and the quantum dot layers 44R and 44G are formed.

In this way, the pixel 20 having the sub-pixels 21R, 21G, and 21B is configured.

Fig. 5 schematically shows light emission of each of the sub-pixels 21R, 21G, and 21B. In FIG. 5 , arrow Lr indicates red light, arrow Lg indicates green light, and arrow Lb indicates blue light, and the number of arrows indicates the amount of light. In addition, the arrangement of each component shown in FIG. 5 does not coincide with the arrangement of each component shown in FIG. 4 for convenience.

In the red sub-pixel 21R, first, blue light Lb is emitted from the OLED 32 as shown in FIG. 5 . Then, the blue light Lb is converted into the red light Lr by the red quantum dot layer 44R and is emitted from the quantum dot layer 44R. At this time, since the conversion rate of the quantum dot layer 44R is not 100%, the unconverted blue light Lb is emitted from the quantum dot layer 44R together with the red light Lr. In addition, in the quantum dot layer 44R, a part of the blue light Lb loses activity or is absorbed. Subsequently, the red light Lr emitted from the quantum dot layer 44R passes through the red color filter 42R and is emitted from the display surface of the panel 2 . At this time, the blue light Lb emitted from the quantum dot layer 44R is absorbed by the color filter 42R.

In the green sub-pixel 21G, first, the blue light Lb is emitted from the OLED 32 as shown in FIG. 5 . Subsequently, the blue light Lb is converted into green light Lg by the green quantum dot layer 44G and is emitted from the quantum dot layer 44G. At this time, since the conversion rate of the quantum dot layer 44G is not 100%, the unconverted blue light Lb is emitted together with the green light Lg from the quantum dot layer 44G. Also, in the quantum dot layer 44G, a part of the blue light Lb loses activity or is absorbed. Subsequently, the green light Lg emitted from the quantum dot layer 44G passes through the green color filter 42G and is emitted from the display surface of the panel 2 . At this time, the blue light Lb emitted from the quantum dot layer 44G is absorbed by the color filter 42G.

In the blue subpixel 21B, first, blue light Lb is emitted from the OLED 32 as shown in FIG. 5 . Next, the blue light Lb is emitted from the display surface of the panel 2 as it is without passing through the quantum dot layer or the color filter.

In this embodiment, with respect to the quantum dot layers 44R and 44G, which are on the entry side of external light with respect to the quantum dot layers 44R and 44G, the color filters 42R and 42G on the display surface side of the panel 2 and the glass substrate ( 40), a semi-permeable film 41 is formed. The semi-transmissive film 41 functions as a light-reducing film for reducing external light incident on the quantum dot layers 44R and 44G. That is, a part of the external light entering from the display surface side of the panel 2 is reflected by the semi-transmissive film 41 . External light incident on the quantum dot layers 44R and 44G can be reduced due to absorption of external light by the semi-transmissive film 41, and quantum dot excitation by external light can be reduced to reduce light emission of the quantum dot layers 44R and 44G. . Accordingly, image quality can be improved in a bright environment, and specifically, display contrast can be improved. In addition, the external light reflected by the semi-transmissive film 41 is prevented from being emitted from the display surface of the panel 2 by the anti-reflection film 48 .

In addition, the light due to the original light emission of the sub-pixels 41R and 41G emitted from the quantum dot layers 44R and 44G is reflected back by the anode electrode 34 as a reflective electrode even though it is reflected by the semi-transmissive film 41 . It can be emitted from the display surface of the panel 2 . Therefore, the decrease in luminance due to the semi-transmissive film 41 can be suppressed.

As described above, according to the present embodiment, image quality can be improved in a bright environment.

<Modified example>

A display device according to a modification of the present embodiment will be described with reference to FIG. 6 . 6 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a modification of the present embodiment.

In this embodiment, although the case where the semi-transmissive film|membrane 41 is formed between the color filters 42R and 42G and the glass substrate 40 as shown in FIG. 4 was demonstrated, it is not limited to this.

As shown in FIG. 6 , the semi-transmissive film 41 may be formed between the color filter 42R and the quantum dot layer 44R and between the color filter 42G and the quantum dot layer 44G. Also in the configuration shown in FIG. 6 , the semi-transmissive film 41 is on the display surface side of the panel 2 with respect to the quantum dot layers 44R and 44G, which is the entry side of external light with respect to the quantum dot layers 44R and 44G. is formed in Therefore, even in the case illustrated in FIG. 6 , the image quality can be improved in a bright environment as in the case illustrated in FIG. 4 .

<Second embodiment>

A display device according to a second embodiment of the present invention will be described with reference to FIG. 7 . 7 is a schematic diagram showing a schematic configuration of a pixel of the display device according to the present embodiment. In addition, the same reference numerals are assigned to the same components as those of the display device according to the first embodiment, and descriptions thereof are omitted or simplified.

In the first embodiment, the OLED is formed on the element substrate 100 and the configuration in which the color filter and the quantum dot layer are formed on the color filter substrate 200 has been described, but it is not limited thereto. The OLED, the quantum dot layer, and the color filter may be formed on a single glass substrate.

In this embodiment, the case where the pixel which contains the same three sub-pixels as 1st Embodiment is formed on a single glass substrate is demonstrated.

As shown in FIG. 7 , the pixel 20 in the panel 2 includes a red sub-pixel 21R, a green sub-pixel 21G, and a blue sub-pixel 21B.

The panel 2 has a glass substrate 50 , but does not have a color filter substrate opposing the glass substrate 50 . The display device according to the present embodiment is a top emission type in which light is emitted from the element formation surface side of the glass substrate 50 . That is, in the display device according to the present embodiment, the element formation surface side of the glass substrate 50 is the display surface side.

On the element formation surface of the glass substrate 50, which is a transparent substrate, three anode electrodes 34 are formed so as to correspond to the sub-pixels 21R, 21G, and 21B. On each anode electrode 34 , a blue organic light emitting layer 36 is formed. A common cathode electrode 38 is formed on each blue organic light emitting layer 36 . In this way, in each pixel 20, an OLED 32 is formed for each of the sub-pixels 21R, 21G, and 21B as in the first embodiment. On the cathode electrode 38, the sealing film 52 which encapsulates the OLED 32 is formed.

On the encapsulation film 52 , a red quantum dot layer 44R is formed to face the OLED 32 of the red subpixel 21R. A red color filter 42R is formed on the quantum dot layer 44R. As described above, the red sub-pixel 21R including the blue OLED 32 , the red quantum dot layer 44R and the red color filter 42R is configured.

Further, on the encapsulation film 52 , a green quantum dot layer 44G is formed to face the OLED 32 of the green subpixel 21G. A green color filter 42G is formed on the quantum dot layer 44G. As described above, the green sub-pixel 21G including the blue OLED 32 , the green quantum dot layer 44G and the green color filter 42G is configured.

On the color filters 42R and 42G, a semi-transmissive film 41 similar to that of the first embodiment is formed. In this embodiment, with respect to the quantum dot layers 44R and 44G, which are on the entry side of external light with respect to the quantum dot layers 44R and 44G, the color filters 42R and 42G on the display surface side of the panel 2 and the cover described later. A semi-permeable film 41 is formed between the films 56 . That is, the semi-transmissive film 41 is formed on the side opposite to the OLED 32 with respect to the quantum dot layers 44R and 44G, and on the opposite side to the quantum dot layers 44R and 44G with respect to the color filters 42R and 42G. has been

On the other hand, neither a color filter nor a quantum dot layer is formed on the encapsulation film 52 so as to face the OLED 32 of the blue sub-pixel 21B. Therefore, the blue sub-pixel 21B has the blue OLED 32 , but does not have a blue color filter, other color filters, or a quantum dot layer. That is, the sub-pixel 21B emits blue light without passing through the blue color filter or other color filters.

Quantum dot layers 44R, 44G, color filters 42R, 42G, and a semi-transmissive layer 41 are formed on the entire surface of the glass substrate 50 on which the sub-pixels 21R, 21G, 21B and the semi-transmissive layer 41 are formed. A sealing film 54 for sealing is formed. On the sealing film 54, the cover film 56 which consists of a transparent resin film etc. is formed. On the cover film 56 , an antireflection film 48 is formed.

As in the present embodiment, a pixel including three sub-pixels may be formed on a single glass substrate. Also in this embodiment, similarly to the first embodiment, the image quality can be improved in a bright environment.

<Modified example>

A display device according to a modification of the present embodiment will be described with reference to FIG. 8 . 8 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a modification of the present embodiment.

In this embodiment, as shown in FIG. 7, although the case where the semi-transmissive film|membrane 41 is formed between the color filters 42R, 42G and the cover film 56 was demonstrated, it is not limited to this.

As shown in FIG. 8 , the semi-transmissive film 41 may be formed between the color filter 42R and the quantum dot layer 44R and between the color filter 42G and the quantum dot layer 44G. Also in the configuration shown in FIG. 8 , the semi-transmissive film 41 is on the display surface side of the panel 2 with respect to the quantum dot layers 44R and 44G, which is the entry side of external light with respect to the quantum dot layers 44R and 44G. is formed in Therefore, even in the case shown in FIG. 8, the image quality can be improved in the same bright environment as in the case shown in FIG.

<Third embodiment>

A display device according to a third embodiment of the present invention will be described with reference to FIG. 9 . 9 is a schematic diagram showing a schematic configuration of a pixel of the display device according to the present embodiment. In addition, the same reference numerals are assigned to the same components as those of the display devices according to the first and second embodiments, and descriptions thereof are omitted or simplified.

In the above first and second embodiments, although the pixel configuration of the top light emission method has been described, it is not limited thereto. The pixel may be a back light emission type.

In this embodiment, a case in which the pixel including the same three sub-pixels as in the first embodiment is a back light emission type will be described.

As shown in FIG. 9 , the pixel 20 in the panel 2 includes a red sub-pixel 21R, a green sub-pixel 21G, and a blue sub-pixel 21B.

The panel 2 has a glass substrate 60 , but does not have a color filter substrate opposing the glass substrate 60 . The display device according to the present embodiment is a bottom light emission type in which light is emitted from the side opposite to the element formation surface of the glass substrate 60 . That is, in the display device according to the present embodiment, the surface side opposite to the element formation surface side of the glass substrate 60 is the display surface side.

A red color filter 42R and a red quantum dot layer 44R are sequentially stacked on the element formation surface of the glass substrate 60 , which is a transparent substrate, to correspond to the red sub-pixel 21R. The color filter 42R is formed on the glass substrate 60 through the semi-transmissive film 41 .

In addition, on the element formation surface of the glass substrate 60 , a green color filter 42G and a green quantum dot layer 44G are sequentially stacked to correspond to the green sub-pixel 21G. The color filter 42G is formed on the glass substrate 60 through the semi-transmissive film 41 .

In this embodiment, with respect to the quantum dot layers 44R and 44G, which are on the entry side of external light with respect to the quantum dot layers 44R and 44G, the color filters 42R and 42G on the display surface side of the panel 2 and the glass substrate ( 60), a semi-permeable film 41 is formed. That is, the semi-transmissive film 41 is formed on the side opposite to the OLED 32 with respect to the quantum dot layers 44R and 44G, and on the opposite side to the quantum dot layers 44R and 44G with respect to the color filters 42R and 42G. has been

On the other hand, on the element formation surface of the glass substrate 60, neither a color filter nor a quantum dot layer is formed so as to face the blue sub-pixel 21B.

The color filters 42R, 42G, the quantum dot layers 44R, 44G, and the semi-transmissive film 41 are formed on the entire surface of the element formation surface of the glass substrate 60, the color filters 42R, 42G, the quantum dot layers 44R, 44G ) and an encapsulation film 62 for sealing the semi-permeable film 41 are formed.

Three anode electrodes 34 are formed on the encapsulation film 62 to correspond to the sub-pixels 21R, 21G, and 21B. On each anode electrode 34 , a blue organic light emitting layer 36 is formed. A common cathode electrode 38 is formed on each blue organic light emitting layer 36 . In this way, in each pixel 20, an OLED 32 is formed for each of the sub-pixels 21R, 21G, and 21B as in the first embodiment. In addition, in this embodiment, since it is a back light emission system, the anode electrode 34 can be comprised as a transparent electrode.

As described above, the red sub-pixel 21R including the blue OLED 32 , the red quantum dot layer 44R and the red color filter 42R is configured.

In addition, a green sub-pixel 21G having a blue OLED 32 , a green quantum dot layer 44G, and a green color filter 42G is configured.

On the other hand, on the element formation surface of the glass substrate 60, neither a color filter nor a quantum dot layer is formed so that the OLED 32 of the blue sub-pixel 21B may be opposed. Therefore, the blue sub-pixel 21B has the blue OLED 32 , but does not have a blue color filter, other color filters, or a quantum dot layer. That is, the sub-pixel 21B emits blue light without passing through the blue color filter or other color filters.

An encapsulation film 64 for sealing the OLED 32 is formed on the entire surface of the glass substrate 60 on which the cathode electrode 38 is formed.

As in the present embodiment, a pixel including three sub-pixels may be configured as a back light emission method. Also in this embodiment, similarly to the first embodiment, the image quality can be improved in a bright environment.

<Modified example>

A display device according to a modification of the present embodiment will be described with reference to FIG. 10 . 10 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a modification of the present embodiment.

In this embodiment, as shown in FIG. 9, although the case where the semi-transmissive film 41 is formed between the color filters 42R, 42G and the glass substrate 60 was demonstrated, it is not limited to this.

As shown in FIG. 10 , the semi-transmissive film 41 may be formed between the color filter 42R and the quantum dot layer 44R and between the color filter 42G and the quantum dot layer 44G. Also in the configuration shown in FIG. 10 , the semi-transmissive film 41 is on the display surface side of the panel 2 with respect to the quantum dot layers 44R and 44G, which is the entry side of external light with respect to the quantum dot layers 44R and 44G. is formed in Therefore, even in the case shown in FIG. 10, the image quality can be improved in the same bright environment as in the case shown in FIG.

<Fourth embodiment>

A display device according to a fourth embodiment of the present invention will be described with reference to FIG. 11 . 11 is a schematic diagram showing a schematic configuration of a pixel of the display device according to the present embodiment. In addition, the same reference numerals are assigned to the same components as those of the display devices according to the first to third embodiments, and descriptions thereof are omitted or simplified.

In the first to third embodiments described above, in the pixel 20, the configuration in which the semi-transmissive film 41 is used as a light-reducing film for reducing external light incident on the quantum dot layers 44R and 44G has been described. is not limited to Instead of the semi-transmissive film 41, an absorption film absorbing light of a specific wavelength capable of excitation of quantum dots in the quantum dots may be used.

In this embodiment, in the pixel 20, the structure in which the ultraviolet absorption film is used instead of the semitransmissive film 41 in the structure shown in FIG. 4 is demonstrated.

11, between the color filters 42R and 42G on the display surface side of the panel 2 and the glass substrate 40 for the quantum dot layers 44R and 44G, instead of the semi-transmissive film 41 Thus, the ultraviolet absorption film 71 is formed. That is, the ultraviolet absorption film 71 is formed on the side opposite to the OLED 32 with respect to the quantum dot layers 44R and 44G, and on the opposite side to the quantum dot layers 44R and 44G with respect to the color filters 42R and 42G. has been The display surface side of the panel 2 with respect to the quantum dot layers 44R and 44G becomes the entry side of external light with respect to the quantum dot layers 44R and 44G.

The ultraviolet absorption film 71 transmits visible light while absorbing ultraviolet rays capable of excitation of quantum dots in the quantum dot layers 44R and 44G. The ultraviolet absorbing film 71 is not particularly limited, but may be a film containing an ultraviolet absorbing material. The ultraviolet absorbing film 71 is a film containing, for example, zinc oxide, indium tin oxide (ITO), or the like as an ultraviolet absorbing material. The ultraviolet absorbing film 71 functions as a light reducing film for reducing external light incident on the quantum dot layers 44R and 44G. That is, due to the absorption of ultraviolet light by the ultraviolet absorption film 71, ultraviolet rays among external light incident on the quantum dot layers 44R and 44G can be reduced, and the quantum dot layers 44R and 44G emit light by reducing the excitation of the quantum dots by ultraviolet rays. can be reduced. Accordingly, image quality can be improved in a bright environment, and specifically, display contrast can be improved.

As described above, according to the present embodiment, image quality can be improved in a bright environment.

Moreover, although the case where the ultraviolet-ray absorption film 71 which absorbs ultraviolet-ray is used is demonstrated in this embodiment, it is not limited to this. In this embodiment and fifth and sixth embodiments to be described later, instead of the ultraviolet absorbing film 71, a light absorbing film that absorbs light of a specific wavelength that excites quantum dots in the quantum dot layers 44R and 44G can be widely used. there is. For example, instead of the ultraviolet absorbing film 71 , a light absorbing film absorbing light having a wavelength less than or equal to the wavelength of blue light including ultraviolet light, specifically, for example, light having a wavelength of 490 nm or less may be used. By such a light absorption film, excitation of quantum dots can be reduced and light emission of the quantum dot layers 44R and 44G can be reduced. The light absorption film may be configured to transmit at least red light and green light. In addition, the light referred to in this specification is light in a broad sense including not only visible light but also infrared rays and ultraviolet rays.

<Modified example>

A display device according to a modification of the present embodiment will be described with reference to FIG. 12 . 12 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a modification of the present embodiment.

In this embodiment, as shown in FIG. 11, although the case where the ultraviolet-ray absorption film 71 is formed between the color filters 42R, 42G and the glass substrate 40 was demonstrated, it is not limited to this.

As shown in FIG. 12 , the ultraviolet absorption film 71 may be formed between the color filter 42R and the quantum dot layer 44R and between the color filter 42G and the quantum dot layer 44G. Also in the configuration shown in FIG. 12 , the ultraviolet absorption film 71 is on the display surface side of the panel 2 with respect to the quantum dot layers 44R and 44G, which is the entry side of external light with respect to the quantum dot layers 44R and 44G. is formed in Therefore, even in the case illustrated in FIG. 12 , display contrast can be improved in a bright environment as in the case illustrated in FIG. 11 .

<Fifth embodiment>

A display device according to a fifth embodiment of the present invention will be described with reference to FIG. 13 . 13 is a schematic diagram showing a schematic configuration of a pixel of the display device according to the present embodiment. In addition, the same reference numerals are assigned to the same components as those of the display devices according to the first to fourth embodiments, and descriptions thereof are omitted or simplified.

In the fourth embodiment, the case in which the ultraviolet absorbing film 71 is used in place of the semi-transmissive film 41 in the configuration shown in FIG. 4 has been described, but it is not limited thereto.

In this embodiment, the structure in which the ultraviolet absorption film 71 is used instead of the semitransmissive film 41 in the structure shown in FIG. 7 is demonstrated.

As shown in FIG. 13 , between the color filters 42R and 42G on the display surface side of the panel 2 and the cover film 56 for the quantum dot layers 44R and 44G, instead of the semi-transmissive film 41 , The same ultraviolet absorption film 71 as that of the fourth embodiment is formed. That is, the ultraviolet absorption film 71 is formed on the side opposite to the OLED 32 with respect to the quantum dot layers 44R and 44G, and on the opposite side to the quantum dot layers 44R and 44G with respect to the color filters 42R and 42G. has been The display surface side of the panel 2 with respect to the quantum dot layers 44R and 44G becomes the entry side of external light with respect to the quantum dot layers 44R and 44G.

A pixel including three sub-pixels may be formed on a single glass substrate like this embodiment. Also in this embodiment, similarly to the fourth embodiment, the image quality can be improved in a bright environment.

<Modified example>

A display device according to a modification of the present embodiment will be described with reference to FIG. 14 . 14 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a modification of the present embodiment.

In this embodiment, although the case where the ultraviolet absorption film 71 is formed between the color filters 42R, 42G and the cover film 56 as shown in FIG. 13 was demonstrated, it is not limited to this.

As shown in FIG. 14 , the ultraviolet absorption film 71 may be formed between the color filter 42R and the quantum dot layer 44R and between the color filter 42G and the quantum dot layer 44G. Also in the configuration shown in FIG. 14 , the ultraviolet absorption film 71 is on the display surface side of the panel 2 with respect to the quantum dot layers 44R and 44G, which is the entry side of external light with respect to the quantum dot layers 44R and 44G. is formed in Therefore, in the case shown in FIG. 14 as well as in the case shown in FIG. 13, image quality can be improved in a bright environment.

<Sixth embodiment>

A display device according to a sixth embodiment of the present invention will be described with reference to FIG. 15 . 15 is a schematic diagram showing a schematic configuration of a pixel of the display device according to the present embodiment. In addition, the same reference numerals are assigned to the same components as those of the display devices according to the first to fifth embodiments, and descriptions thereof are omitted or simplified.

In the fourth embodiment, the case in which the ultraviolet absorbing film 71 is used in place of the semi-transmissive film 41 in the configuration shown in FIG. 4 has been described, but it is not limited thereto.

In this embodiment, the structure in which the ultraviolet absorption film 71 is used instead of the semitransmissive film 41 in the structure shown in FIG. 9 is demonstrated.

15, between the color filters 42R and 42G on the display surface side of the panel 2 and the glass substrate 60 for the quantum dot layers 44R and 44G, instead of the semi-transmissive film 41 Thus, the ultraviolet absorbing film 71 similar to that of the fourth embodiment is formed. That is, the ultraviolet absorption film 71 is formed on the side opposite to the OLED 32 with respect to the quantum dot layers 44R and 44G, and on the opposite side to the quantum dot layers 44R and 44G with respect to the color filters 42R and 42G. has been The display surface side of the panel 2 with respect to the quantum dot layers 44R and 44G becomes the entry side of external light with respect to the quantum dot layers 44R and 44G.

As in the present embodiment, a pixel including three sub-pixels may be configured as a back light emission method. Also in this embodiment, similarly to the fourth embodiment, the image quality can be improved in a bright environment.

<Modified example>

A display device according to a modification of the present embodiment will be described with reference to FIG. 16 . 16 is a cross-sectional view showing a schematic configuration of a pixel of a display device according to a modification of the present embodiment.

In this embodiment, as shown in FIG. 15, although the case where the ultraviolet absorption film 71 is formed between the color filters 42R and 42G and the glass substrate 60 was demonstrated, it is not limited to this.

As shown in FIG. 16 , the ultraviolet absorption film 71 may be formed between the color filter 42R and the quantum dot layer 44R and between the color filter 42G and the quantum dot layer 44G. Also in the configuration shown in FIG. 16 , the ultraviolet absorption film 71 is on the display surface side of the panel 2 with respect to the quantum dot layers 44R and 44G, which is the entry side of external light with respect to the quantum dot layers 44R and 44G. is formed in Therefore, even in the case shown in FIG. 16, the image quality can be improved in the same bright environment as in the case shown in FIG.

<Modified embodiment>

This invention is not limited to the said embodiment, In the range which does not deviate from the meaning of this invention, a change is possible suitably.

For example, in the said embodiment, although the case where OLED was used as a light emitting element was demonstrated as an example, it is not limited to this. Instead of OLED, various light emitting devices can be used.

Also, in the above embodiment, the case in which the pixel 20 has three sub-pixels 21R, 21G, and 21B has been described as an example, but the present invention is not limited thereto. The pixel 20 may have a plurality of sub-pixels of two or more, or may have a single sub-pixel.

In addition, although the case where the semi-transmissive film 41 or the ultraviolet-ray absorption film 71 is formed with respect to the two quantum dot layers 44R and 44G was demonstrated as an example in the said embodiment, it is not limited to this. The semi-transmissive film 41 or the ultraviolet absorption film 71 may be formed on at least one of the quantum dot layers 44R and 44G.

1: Timing controller
2: panel
3: Source drive IC
4: Gate drive IC
20: pixel
21: hatchery
21R, 21G, 21B: sub-pixel
30: glass substrate
34: anode electrode
36: blue organic light emitting layer
38: cathode electrode
40: glass substrate
41: semi-permeable membrane
42R, 42G: color filter
44R, 44G: quantum dot layer
50: glass substrate
60: glass substrate
71: ultraviolet absorption film
100: device substrate
200: color filter substrate
D: diode
DL: data line
GL: gate line

Claims (18)

A pixel comprising a light emitting element and a quantum dot layer for converting a wavelength of light generated from the light emitting element;
It is formed on the opposite side to the light emitting element with respect to the quantum dot layer, characterized in that it has a light reducing film for reducing external light incident on the quantum dot layer,
The pixel further includes a color filter between the light reduction film and the quantum dot layer, wherein the light reduction film is formed on a side opposite to the quantum dot layer with respect to the color filter.
The method of claim 1,
The light-reducing film is a semi-transmissive film or a light-absorbing film that absorbs light having a wavelength less than or equal to the wavelength of blue light including ultraviolet light.
3. The method according to claim 1 or 2,
the pixel has a first sub-pixel of a first color and a second sub-pixel of a second color;
The first sub-pixel includes the light emitting element emitting light of the second color, a first quantum dot layer that converts light of the second color as the quantum dot layer into light of the first color, and the color filter and a color filter of the first color as
The second sub-pixel has the light-emitting element emitting light of the second color,
The light reduction film is formed in the first sub-pixel.
4. The method of claim 3,
The pixel further has a third sub-pixel of a third color,
The third sub-pixel includes the light emitting element emitting light of the second color, a second quantum dot layer that converts the light of the second color as the quantum dot layer into light of the third color, and the color filter having a color filter of the third color as
The light reduction film is formed in the third sub-pixel.
4. The method of claim 3,
The second sub-pixel emits light of the second color without passing through a color filter.
3. The method of claim 2,
The semi-transmissive layer is formed to have a thickness smaller than that of the quantum dot layer and the color filter.
The method of claim 1,
An antireflection film having a quarter wave plate and a polarizing plate is provided on the light reduction film, and the light reduction film is positioned between the antireflection film and the color filter.
4. The method of claim 3,
The first color is red or green,
The second color is blue.
3. The method according to claim 1 or 2,
The light reduction film is a metal film, characterized in that the display device.
10. The method of claim 9,
The metal film is an aluminum film.
3. The method according to claim 1 or 2,
The light reduction film is a display device, characterized in that it is an ultraviolet absorption film that absorbs ultraviolet rays.
12. The method of claim 11,
The ultraviolet absorbing film is a film containing zinc oxide or indium tin oxide.
3. The method according to claim 1 or 2,
The light emitting element is an organic light emitting diode.
4. The method of claim 3,
The second sub-pixel does not include a quantum dot layer.
3. The method according to claim 1 or 2,
a first substrate on which the light emitting element is formed;
and a second substrate disposed to face the first substrate and having the quantum dot layer and the photoresist film formed thereon.
3. The method according to claim 1 or 2,
and a substrate on which the light emitting element, the quantum dot layer, and the light reduction film are formed on one surface.
17. The method of claim 16,
The display device, wherein the one surface side of the substrate is a display surface side.
17. The method of claim 16,
The display device according to claim 1, wherein a side of the substrate opposite to the side of the one surface is a side of the display surface.

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