KR102813657B1 - Optical film and display device comprising the same - Google Patents

Abstract

One embodiment of the present invention relates to an optical film arranged on a display surface of a display panel, and provides an optical film including a shutter plate that delays light by 0 or λ/2 phase in a display mode and delays light by λ/4 phase in a non-display mode, and a wavelength-selective reflector that corresponds to at least a portion of each pixel area and reflects light belonging to a predetermined wavelength band among light incident on the display surface. Since, in addition to light emitted from elements of each pixel area by the shutter plate and wavelength-selective reflector in the display mode, light belonging to a predetermined wavelength band among external light reflected by the wavelength-selective reflector can be emitted as display light, the light output efficiency of the display panel can be improved.

Description

OPTICAL FILM AND DISPLAY DEVICE COMPRISING THE SAME

The present invention relates to an optical film disposed on a display surface and a display device including the same.

Display devices are applied to various electronic devices such as TVs, mobile phones, laptops, and tablets. To this end, research is being conducted to develop display devices that are thinner, lighter, and have lower power consumption.

Examples of such display devices include liquid crystal display devices (LCD), plasma display panel devices (PDP), field emission display devices (FED), electro-wetting display devices (EWD), and electro-luminescence display devices (ELDD).

In general, a display device includes a display panel (hereinafter referred to as “display panel” or “panel”) that emits light for displaying an image. A general display panel includes a pair of substrates facing each other and a light-emitting material or liquid crystal material disposed between the pair of substrates.

Meanwhile, the display device may further include an optical film attached to the display surface of the display panel and for preventing external light from being reflected on the display surface. In particular, an electroluminescent display device having a structure that does not include a polarizing plate may include an optical film disposed on the display surface and for preventing external light from being reflected.

An optical film for preventing external light reflection may include a polarizing plate that linearly polarizes light and a phase retardation plate that retards the phase of light by λ/4. The optical film transmits display light emitted from the display panel. In addition, the optical film blocks external light that is incident on the display panel and reflected by the display panel from being emitted together with the display light.

Since these optical films are placed on the display surface, there is a problem in that at least 50% of the display light emitted through the display surface is absorbed or reflected by the optical film, thereby reducing the light output efficiency of the display panel, and thus there is a limit to improving the brightness of the display device.

Accordingly, the present invention provides an optical film capable of improving the light output efficiency of a display panel while preventing external light reflection, and a display device including the same.

The purposes of the present invention are not limited to the purposes mentioned above, and other purposes and advantages of the present invention which are not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. In addition, it will be easily understood that the purposes and advantages of the present invention can be realized by the means and combinations thereof indicated in the claims.

One example of the present invention relates to an optical film disposed on a display surface of a display panel, comprising: a shutter plate that delays light by 0 or λ/2 phase in a display mode and by λ/4 phase in a non-display mode; and a wavelength-selective reflector that corresponds to at least a portion of each pixel area and reflects light belonging to a predetermined wavelength band among light incident on the display surface.

Here, when a plurality of pixel areas include a first pixel area emitting light of a first wavelength band corresponding to a first color, a second pixel area adjacent to the first pixel area and emitting light of a second wavelength band corresponding to a second color different from the first color, and a third pixel area adjacent to any one of the first and second pixel areas and emitting light of a third wavelength band corresponding to a third color different from the first and second colors, the wavelength-selective reflector is arranged in at least a part of the first pixel area and includes a first wavelength reflection area that reflects light of the first wavelength band among light incident on the display surface and absorbs or transmits the remaining light, a second wavelength reflection area that is arranged in at least a part of the second pixel area and reflects light of the second wavelength band among light incident on the display surface and absorbs or transmits the remaining light, and a third pixel area that is arranged in at least a part of the third pixel area and includes a second wavelength reflection area that reflects light of the second wavelength band among light incident on the display surface and absorbs or transmits the remaining light. The light may include a third wavelength reflection region that reflects light of the third wavelength band and absorbs or transmits the remaining light.

In addition, the first, second and third wavelength reflection areas of the wavelength selective reflector can be arranged in non-effective areas corresponding to pixel circuits that drive elements that emit light among the first, second and third pixel areas, respectively.

The color filter plate may include a first color filter corresponding to the first pixel area and transmitting light of the first wavelength band, a second color filter corresponding to the second pixel area and transmitting light of the second wavelength band, and a third color filter corresponding to the third pixel area and transmitting light of the third wavelength band.

In addition to the light emitted from the elements of each pixel area by the shutter plate and wavelength-selective reflector of this display mode, light belonging to a predetermined wavelength band reflected by the wavelength-selective reflector among external light can be emitted as display light. That is, display light can be emitted not only in the effective area corresponding to the element emitting light among each pixel area, but also in the ineffective area corresponding to the pixel circuit driving the element. Therefore, there is an advantage that the light output efficiency of the display panel can be improved.

In addition, since external light reflected in the effective or ineffective area can be blocked by the shutter plate in the non-display mode, there is an advantage in that external light reflection can be reduced.

And, another example of the present invention provides a display device including the optical film and the display panel.

These display devices have the advantage of improving the light output efficiency of the display panel while reducing external light reflection due to the optical film.

An optical film according to one embodiment of the present invention includes a polarizing plate, a shutter plate that delays light by 0 or λ/2 phase in a display mode and delays light by λ/4 phase in a non-display mode, and a wavelength-selective reflector that corresponds to at least a portion of each of a plurality of pixel areas and reflects light belonging to a predetermined wavelength band among light incident on a display surface side of a display panel.

The shutter plate of the display mode does not change the polarization form of light. Accordingly, not only the light emitted from the display panel and the color filter plate, but also the external light reflected from the color filter plate or the wavelength-selective reflector can be emitted as display light by passing through the shutter plate and the polarizing plate of the display mode. That is, since the display light of each pixel area can be emitted in the effective area and the ineffective area of each pixel area, the light output efficiency of the display panel can be improved. As a result, the brightness of the display device can be improved.

The effects of this specification are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

FIG. 1 is a drawing showing a display device according to one embodiment of the present invention.
Figure 2 is a drawing showing an example of the display panel of Figure 1.
FIG. 3 is a drawing showing an example of an equivalent circuit of one pixel area of FIG. 2.
Figure 4 is a drawing showing an example of a cross-section of a display device corresponding to one pixel area.
Figure 5 is a drawing showing another example of a cross-section of a display device corresponding to one pixel area.
Figure 6 is a drawing showing an example of a plane for the display panel of Figure 1.
Fig. 7 is a drawing showing an example of a plane for the color filter plate of Fig. 1.
Fig. 8 is a drawing showing another example of a plane for the color filter plate of Fig. 1.
FIG. 9 is a drawing showing an example of a plane for a wavelength-selective reflector among the optical films of FIG. 1.
Fig. 10 is a drawing showing an example of a plane for a shutter plate among the optical films of Fig. 1.
Figure 11 is a drawing showing an example of operation when the shutter plate of Figure 10 is in non-display mode.
Figure 12 is a drawing showing an example of operation when the shutter plate of Figure 10 is in display mode.
FIGS. 13, 14 and 15 are diagrams showing examples of cross sections and optical paths in display modes for lines I-I', II-II' and III-III' of FIG. 10, respectively, according to the first embodiment of the present invention.
FIG. 16 is a diagram showing an example of a cross-section along line I-I' of FIG. 10 according to the first embodiment of the present invention and an optical path in a non-display mode.
FIG. 17 is a diagram showing an example of a cross-section along line I-I' of FIG. 10 according to a second embodiment of the present invention and an optical path in a non-display mode.
FIG. 18 is a diagram showing an example of a cross-section along line II-II' of FIG. 10 according to a third embodiment of the present invention and an optical path in a non-display mode.

The above-mentioned objects, features and advantages will be described in detail below with reference to the attached drawings, so that those with ordinary skill in the art to which the present invention pertains can easily practice the technical idea of the present invention. In describing the present invention, if it is judged that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted. Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

Hereinafter, the phrase “any configuration is disposed on (or below)” a component or “on (or below)” a component may mean not only that any configuration is disposed in contact with the upper surface (or lower surface) of said component, but also that another configuration may be interposed between said component and any configuration disposed on (or below) said component.

Additionally, when a component is described as being "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through other components.

Hereinafter, a display device and an optical film provided therein according to each embodiment of the present invention will be described.

First, a display device according to one embodiment of the present invention will be described with reference to FIG. 1.

FIG. 1 is a drawing showing a display device according to one embodiment of the present invention.

As illustrated in FIG. 1, a display device (10) according to one embodiment of the present invention includes a display panel (100) including a plurality of pixel areas, and an optical film (300) that is disposed on a display surface of the display panel (100) from which light (IMAGE LIGHT) is emitted and prevents reflection of external light.

The display panel (100) can be implemented with any structure that uses a self-luminous element, such as an electroluminescent display panel or an organic light-emitting display panel.

The display surface of the display panel (100) can be selected as at least one of the upper surface and the lower surface that face each other. Fig. 1 illustrates a case where the display surface is the upper surface of the display panel (100).

In addition, the display device (10) according to one embodiment of the present invention may further include a color filter plate (200) that is placed between the display panel (100) and the optical film (300) and converts into a wavelength band of light.

In other words, the display device (10) may include a display panel (100), a color filter plate (200) disposed on a display surface of the display panel (100), and an optical film (300) disposed on the color filter plate (200).

Although not shown separately, the color filter plate (200) may be implemented as part of an optical film (300).

Alternatively, although not shown separately, if the display panel (100) includes two or more elements corresponding to each pixel area and emitting light of different colors, or if the display panel (100) incorporates a color filter, the display device (10) may not have a color filter plate (200). In this case, the display device (10) may have a structure including a display panel (100) and an optical film (300) arranged on a display surface of the display panel (100).

Referring to FIGS. 2 and 3, an example in which the display panel (100) is an organic light-emitting display panel will be described.

Fig. 2 is a drawing showing an example of the display panel of Fig. 1. Fig. 3 is a drawing showing an example of an equivalent circuit of one pixel area of Fig. 2.

As shown in Fig. 2, the display device (10) includes a display panel (100) and a panel driving unit (11, 12, 13) that drives the display panel (100).

The display panel (100) defines a plurality of pixel areas (PA) arranged in a matrix in a display area (AA), includes a circuit array for driving the plurality of pixel areas (PA), and an element array for emitting light from each of the plurality of pixel areas (PA).

The circuit array includes a plurality of pixel circuits corresponding to a plurality of pixel areas (PAs), and scan lines (15a, 15b) and data lines (14) that supply driving signals to each pixel circuit. Here, when each pixel circuit includes first and second transistors driven by different scan signals, the scan lines include first and second scan lines (15a, 15b) corresponding to the first and second scan signals.

The data line (14) corresponds to each vertical line composed of pixel areas arranged vertically in parallel among a plurality of pixel areas (PA) and supplies a data signal (VDATA).

The first and second scan lines (15a, 15b) correspond to each horizontal line composed of pixel areas arranged horizontally in parallel among a plurality of pixel areas (PA) and supply first and second scan signals (SCAN1, SCAN2).

In addition, the circuit array may further include a first driving power line supplying a first driving power supply (VDD), a second driving power line supplying a second driving power supply (VSS) having a lower voltage than the first driving power supply (VDD), and a reference power line supplying a reference power supply (VREF).

The panel driving unit (11, 12, 13) includes a data driving unit (12) that drives the data line (14) of the display panel (100), a gate driving unit (13) that drives the first and second scan lines (15) of the display panel (100), and a timing controller (11) that controls the driving timing of the data driving unit (12) and the gate driving unit (13).

The timing controller (11) rearranges digital video data (RGB) input from the outside to match the resolution of the display panel (100) and supplies the rearranged digital video data (RGB') to the data driving unit (12).

And, the timing controller (11) supplies a data control signal (DDC) for controlling the operation timing of the data driving unit (12) and a gate control signal (GDC) for controlling the operation timing of the gate driving unit (13) based on timing signals such as a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), a dot clock signal (DCLK), and a data enable signal (DE).

The gate driving unit (13) sequentially supplies first and second scan signals (SCAN1, SCAN2) to the first and second scan lines (15a, 15b) of each horizontal line based on a gate control signal (GDC). For example, the first scan signal (SCAN1) may be a driving signal for selecting a horizontal line to which a data signal (VDATA) is to be supplied, and the second scan signal (SCAN2) may be a driving signal for selecting a horizontal line to be initialized by a reference power supply (VREF).

The data driving unit (12) converts the rearranged digital video data (RGB') into an analog data voltage based on a data control signal (DDC). Then, the data driving unit (12) supplies a data signal (VDATA) to the pixel area of each horizontal line for each horizontal period based on the rearranged digital video data (RGB') and the analog data voltage.

As illustrated in FIG. 3, a pixel circuit (PC) corresponding to each pixel area (PA) may include a driving transistor (DT), first and second transistors (T1, T2), and a storage capacitor (Cst).

A driving transistor (DT) is arranged in series with an organic light-emitting device (OLED) between first and second driving power lines (16, 17). Here, the first driving power line (16) supplies a first driving power (VDD), and the second driving power line (17) supplies a second driving power (VSS).

The first transistor (T1) is placed between the data line (14) and the gate electrode (ND1) of the driving transistor (DT).

When the first transistor (T1) is turned on based on the first scan signal (SCAN1) of the first scan line (15a), it supplies a data signal (VDATA) to the first node (ND1). The first node (ND1) is a contact point between the first transistor (ST1) and the gate electrode of the driving transistor (DT).

A storage capacitor (Cst) is placed between a first node (ND1) and a second node (ND2). The second node (ND2) is a contact point between a driving transistor (DT) and an organic light-emitting device (OLED).

These storage capacitors (Cst; Capacitor_storage) are charged based on the data signal (VDATA) supplied to the first node (ND1) through the turned-on first transistor (ST).

And, the driving transistor (DT) is turned on based on the data signal (VDATA) and the charge voltage of the storage capacitor (Cst), and supplies the driving current corresponding to the data signal (VDATA) to the second node (ND2), i.e., the organic light-emitting device (OLED).

The second transistor (T2) is placed between the reference power line (18) and the second node (ND2).

When the second transistor (T2) is turned on based on the second scan signal (SCAN2) of the second scan line (15b), it supplies the reference power (VREF) of the reference power line (18) to the second node (ND2). At this time, the second node (ND2) is initialized to the reference power (VREF).

Next, examples of cross-sections of display devices are described with reference to FIGS. 4 and 5.

Fig. 4 is a drawing showing an example of a cross-section of a display device corresponding to one pixel area. Fig. 5 is a drawing showing another example of a cross-section of a display device corresponding to one pixel area.

As illustrated in FIG. 4, the display panel (100) may include a circuit array (110) disposed on a substrate (101), an element array (120) disposed on the circuit array (110), and a sealing layer (130) disposed on the element array (120).

Some of each pixel area (PA) is an effective area (EA) where light is emitted by the organic light-emitting diode (OLED), and the remaining area is a non-effective area (NEA) corresponding to the circuitry (PC) that drives the organic light-emitting diode (OLED).

Among the pixel circuits (PC) corresponding to one pixel area (PA), a driving transistor (DT) includes an active layer (ACT) arranged on a substrate (101) and a gate electrode (GE) arranged on a gate insulating film (102) covering the active layer (ACT). In addition, the driving transistor (DT) may further include a source electrode (SE) and a drain electrode (DE) arranged on an interlayer insulating film (103) covering the gate electrode (GE).

Although not shown separately, the first and second transistors (T1, T2) among the pixel circuits (PC) corresponding to one pixel area (PA) may have the same structure as the driving transistor (DT).

Alternatively, although not shown separately, the first and second transistors (T1, T2) may have a different structure from the driving transistor (DT). For example, the driving transistor (DT) may include an active layer of an oxide semiconductor, and the first and second transistors (T1, T2) may include an active layer of LTPS.

The active layer (ACT) includes a channel area (CA) overlapping the gate electrode (GE) and first and second electrode areas (EA1, EA2; Electrode Areas) corresponding to both sides of the channel area (CA).

The active layer (ACT) may be made of low-temperature polysilicon (LTPS). In this case, the channel region (CA) may be made of an undoped semiconductor material, and the first and second electrode regions (EA1, EA2) may be made of a semiconductor material doped with a higher concentration of dopant than the channel region (CA).

For example, one of the first and second electrode regions (EA1, EA2) (e.g., the first electrode region (EA1)) may be connected to the source electrode (SE), and the other one (e.g., the second electrode region (EA2)) may be connected to the drain electrode (DE).

The source electrode (SE) can be connected to the first power line (16), and the drain electrode (DE) can be connected to an organic light emitting device (OLED).

These source electrodes (SE) and drain electrodes (DE) are covered with an overcoat film (104).

In addition, although not illustrated in detail in FIG. 4, the first and second scan lines (15a, 15b), data line (14), first driving power line (16) and reference power line (18) of the display panel (100) may be arranged on the same layer as the respective electrodes (GE, SE, DE) of the driving transistor (DT).

For example, the first and second scan lines (15a, 15b) may be arranged horizontally on the same layer as the gate electrode (GE). In addition, the data line (14), the first driving power line (16), and the reference power line (18) may be arranged vertically on the same layer as the source electrode (SE) and the drain electrode (DE).

An organic light-emitting device (OLED) corresponding to one pixel area (PA) of the element array (120) is placed on an overcoat film (104) covering a driving transistor (DT), and can be connected to the driving transistor (DT) at least through a contact hole penetrating the overcoat film (104).

An organic light-emitting device (OLED) includes first and second electrodes (121, 122) that face each other, and an organic material layer (123) disposed between the first and second electrodes (121, 122). In addition, the device array (120) may further include a bank film (124) that covers an edge of the first electrode (121).

The bank film (124) corresponds to the outer edge of each pixel area (PA) and the non-effective area (NEA) of each pixel area (PA). That is, the bank film (124) is placed in an area of each pixel area (PA) where light is not emitted.

The first electrode (121) corresponds to the effective area (EA) of each pixel area (PA).

The organic material layer (123) corresponds to two or more mutually continuous pixel areas (PA) and can be placed on the first electrode (121) and the bank film (124).

For example, the organic material layer (123) may include a hole transport layer, at least one light-emitting layer, and an electron transport layer. In addition, the organic material layer (123) may further include at least one of a hole injection layer and an electron injection layer.

Alternatively, the organic material layer (123) may include at least one stack. Each stack includes a hole transport layer, an emission layer, and an electron transport layer.

The second electrode (122) corresponds to two or more mutually continuous pixel areas (PA) and is placed on the organic material layer (123).

When the display device (10) is a cross-sectional light-emitting type that emits display light from one of the first and second surfaces (the upper surface and the back surface of FIG. 4), one of the first and second electrodes (121, 122) of the organic light-emitting device (OLED) facing the display surface from which the display light is emitted may be made of a transparent conductive material, and the other may be made of an opaque metallic material having reflectivity.

Alternatively, both the first and second electrodes (121, 122) of the organic light-emitting device (OLED) may be made of a transparent conductive material.

An array of devices (120) including an organic light-emitting diode (OLED) may be covered with a sealing layer (140) to protect the organic material layer (123) from moisture or oxygen. The sealing layer (140) is disposed on the second electrode (123).

When the display panel (100) corresponds to a plurality of pixel areas (PA) and includes an organic light-emitting device (OLED) that emits white light, the display device (10) may include a color filter plate (200) for displaying a color image.

The color filter plate (200) is placed on the display surface of the display panel (100) and converts the wavelength band of light emitted from each of a plurality of pixel areas (PA).

For example, as shown in the illustration of FIG. 4, when the display panel (100) is a top-emitting type, the color filter plate (200) may be placed on the top surface of the display panel (100), i.e., on the sealing layer (130).

The plurality of pixel areas (PAs) may include first, second and third pixel areas that are adjacent to each other in either the first or second directions corresponding to the display surface.

The color filter plate (200) includes first, second and third color filters corresponding to the first, second and third pixel areas, respectively.

The first color filter can transmit light of a first wavelength band corresponding to a predetermined first color.

The second color filter can transmit light of a second wavelength band corresponding to a second color different from the first color.

The third color filter can transmit light of a third wavelength band corresponding to a third color different from the first and second colors.

For example, the first, second and third colors can be red, green and blue, which implement white by color mixing.

In addition, the plurality of pixel areas (PA) may further include a fourth pixel area adjacent to at least one of the first, second, and third pixel areas in either the first or second direction. In this case, the color filter plate (200) may further include a fourth color filter corresponding to the fourth pixel area and transmitting white light of the fourth pixel area. Here, the fourth color filter may be formed of a transparent material or a cavity.

A display device (10) according to one embodiment of the present invention includes an optical film (300) that is placed on a display surface of a display panel (100) and prevents reflection of external light.

The optical film (300) is placed on the display panel (100) or the color filter plate (200). The optical film (300) includes a polarizing plate (330), a shutter plate (320) placed between the polarizing plate (300) and the display panel (100), and a wavelength-selective reflector (310) placed between the display panel (100) and the shutter plate (320). At this time, when the display device (10) has a structure including the color filter plate (200), the wavelength-selective reflector (310) is placed between the color filter plate (200) and the shutter plate (320).

In other words, the optical film (300) includes a wavelength-selective reflector (310) disposed on the display surface of the display panel (100), a shutter plate (320) disposed on the wavelength-selective reflector (310), and a polarizing plate (330) disposed on the shutter plate (320).

The wavelength-selective reflector (310) corresponds to a portion of each of the plurality of pixel areas (PA) and reflects light belonging to a predetermined wavelength band among the light incident on the display surface. That is, the wavelength-selective reflector (310) corresponds to a non-effective area (NEA) in each pixel area (PA) where light from the organic light-emitting element is not emitted.

The wavelength-selective reflector (310) may include a first wavelength reflection area arranged in an ineffective area of a first pixel area, a second wavelength reflection area arranged in an ineffective area of a second pixel area, and a third wavelength reflection area arranged in an ineffective area of a third pixel area.

The first wavelength reflection region reflects light of the first wavelength band among the light incident on the display surface, and absorbs or transmits light other than light of the first wavelength band.

The second wavelength reflection region reflects light of the second wavelength band among the light incident on the display surface, and absorbs or transmits the remaining light except for the light of the second wavelength band.

The third wavelength reflection region reflects light of the third wavelength band among the light incident on the display surface, and absorbs or transmits light other than light of the third wavelength band.

For example, the first, second, and third wavelength bands may correspond to red, green, and blue, respectively.

Alternatively, the wavelength selective reflector (310) may further include a fourth wavelength reflective region arranged in an ineffective region of the fourth pixel region. Here, the fourth pixel region is adjacent to one of the first, second and third pixel regions and emits white light.

In this case, the fourth wavelength reflection region reflects light incident on the display surface.

For example, the first, second, third, and fourth wavelength reflection areas of the wavelength-selective reflector (310) may be implemented as a laminated structure of two or more materials having different refractive indices. In this laminated structure, the wavelength band and reflectivity of reflected light, and the wavelength band and transmittance of transmitted light may be derived based on the difference in refractive indices of each interface, the number of laminated layers, the thickness of each material, and the refractive indices of each material.

Here, among two or more materials having different refractive indices, the material with a low refractive index may be selected from SiO ₂ and MgF ₂ , and the material with a high refractive index may be selected from ZrO ₂ , TiO ₂ , Al ₂ O ₃ , and Y ₂ O ₃ .

Alternatively, the first, second, third and fourth wavelength reflection areas of the wavelength selective reflector (310) may be implemented with spiral TiO ₂ . In this case, the wavelength band and reflectivity of light, and the wavelength band and transmittance of transmitted light may be derived depending on the number of twists of the spiral TiO ₂ .

Alternatively, the first, second, third and fourth wavelength reflection areas of the wavelength-selective reflector (310) may be implemented with organic/inorganic fluorescent substances. Here, the organic fluorescent substance may be a material in which the wavelength band of light absorbed and the wavelength band of light excited are derived according to the number of conjugate nodes connected to the organic matrix. For example, the organic matrix may be at least one of Bodipy, Coumarin, Perylene, Naphthalimide and Xanthone.

The shutter plate (320) delays the light by 0 or λ/2 phase in display mode and delays the light by λ/4 phase in non-display mode.

The polarizing plate (330) transmits linear polarization components.

Meanwhile, Fig. 4 illustrates a case where the display panel (100) is a top-emitting type.

Alternatively, the display panel (100) may be a back-lit type.

That is, as shown in FIG. 5, when the display panel (100) is a back-emitting type, the color filter plate (200) is placed on the back of the display panel (100), i.e., under the substrate (101), and the optical film (300) is placed under the color filter plate (200).

An example including a back-emitting display panel (100) illustrated in FIG. 5 is identical to an example including a top-emitting display panel (100) illustrated in FIG. 4, except that a color filter plate (200) and an optical film (300) are positioned under the substrate (101) of the display panel (100), and therefore, a duplicate description thereof is omitted below.

In this way, when the display panel (100) is a bottom-emitting type, since the circuit array (110) is arranged in the path through which the light of the organic light-emitting element (OLED) is emitted, the gap between the organic light-emitting element (OLED) and the display surface is larger than in the case of the top-emitting type. Therefore, compared to the case of the top-emitting type, the black matrix for blocking external light reflection needs to be arranged more widely in the remaining area except for the effective area (EA) of each pixel area (PA). Accordingly, when a black matrix for external light reflection is provided, the bottom-emitting type has the problem that it is difficult to improve the light output efficiency compared to the top-emitting type, and there is a limit to the improvement of brightness.

However, according to the first embodiment of the present invention, there is an advantage in that the light output efficiency and brightness can be improved by utilizing the external light reflection by the wavelength selective reflector (310) arranged in the non-effective area (NEA) of each pixel area (PA) as display light without including a black matrix. In particular, since the display light is emitted also by the wavelength selective reflector (310), even if the wavelength selective reflector (310) for blocking the external light reflection is arranged wider, the emission area of the display light is not reduced, so there is an advantage in that the brightness reduction can be prevented.

Next, with reference to FIGS. 6 to 10, the plane arrangement of the display panel (100), color filter plate (200), and optical film (300) included in the display device (10) according to the first embodiment of the present invention will be described.

FIG. 6 is a drawing showing an example of a plane for the display panel of FIG. 1. FIG. 7 is a drawing showing an example of a plane for the color filter plate of FIG. 1. FIG. 8 is a drawing showing another example of a plane for the color filter plate of FIG. 1. FIG. 9 is a drawing showing an example of a plane for the wavelength selective reflector among the optical films of FIG. 1. FIG. 10 is a drawing showing an example of a plane for the shutter plate among the optical films of FIG. 1.

As illustrated in FIG. 6, the display panel (100) of the display device (10) includes a plurality of pixel areas (PA1, PA2, PA3, PA4).

Each of the plurality of pixel areas (PA1, PA2, PA3, PA4) includes an active area (EA) that emits light and an inactive area (NEA) that does not emit light. In addition, in each pixel area (PA1, PA2, PA3, PA4), an organic light-emitting device (OLED) is arranged in the active area (EA), and a pixel circuit (PC) that drives the organic light-emitting device (OLED) is arranged in the inactive area (NEA). As an example, as illustrated in FIG. 3, the pixel circuit (PC) may include two or more thin film transistors (DT, T1, T2).

As illustrated in FIG. 7, the color filter plate (200) may include first, second, third, and fourth color filters (210, 220, 230, 240) that overlap two or more pixel areas (PA1, PA2, PA3, PA4) forming a unit pixel and transmit light of different colors.

That is, among the plurality of pixel areas (PA1, PA2, PA3, PA4) of the display panel (100), the first, second, third, and fourth pixel areas (PA1, PA2, PA3, PA4) adjacent to each other in the first or second direction and corresponding to different colors can constitute one unit pixel that implements various colors and brightness.

For example, each unit pixel may be composed of first, second, third and fourth pixel areas (PA1, PA2, PA3, PA4) that are arranged in a parallel manner in a first direction (horizontal direction in FIG. 7) and emit red, white, green and blue light, respectively.

As another example, as illustrated in FIG. 8, each unit pixel may be arranged in a first direction (horizontal direction of FIG. 8) and may be composed of first, second, and third pixel areas (PA1, PA2, PA3, PA4) that emit red, green, and blue light, respectively.

And, the color filter plate (200) includes two or more color filters (210, 220, 230, 240) (210, 220, 230) corresponding to two or more different colors.

For example, as in the illustration of FIG. 7, when each unit pixel is composed of first, second, third and fourth pixel areas (PA1, PA2, PA3, PA4) that emit red, green, blue and white light, respectively, the color filter plate (200) may include first, second, third and fourth color filters (210, 220, 230, 240) corresponding to red, green, blue and white, respectively.

Here, each color filter (210, 220, 230, 240) is placed in both the effective area (EA) and the non-effective area (NEA) of each pixel area (PA1, PA2, PA3, PA4), thereby overlapping the organic light-emitting diode (OLED) and pixel circuit (PC) of each pixel area (PA1, PA2, PA3, PA4).

The first color filter (210) corresponds to the first pixel area (PA1) and transmits light of a first wavelength band corresponding to a predetermined first color (e.g., red).

The second color filter (220) corresponds to the second pixel area (PA2) and transmits light of a second wavelength band corresponding to a second color (e.g., green).

The third color filter (230) corresponds to the third pixel area (PA3) and transmits light of a third wavelength band corresponding to a third color (e.g., blue).

The fourth color filter (240) corresponds to the fourth pixel area (PA4) and transmits light of the fourth wavelength band corresponding to the fourth color (e.g., white). Here, the fourth color filter (240) may be made of a transparent material or a cavity.

Alternatively, as illustrated in FIG. 8, when each unit pixel is composed of first, second, and third pixel areas (PA1, PA2, PA3) that emit red, white, green, and blue light, respectively, the color filter plate (200) may be composed only of first, second, and third color filters (210, 220, 230) corresponding to red, green, and blue, respectively.

As illustrated in FIG. 9, a wavelength-selective reflector (310) among the optical films (300) is placed on the color filter plate (200) and corresponds to a non-effective area (NEA) of each of a plurality of pixel areas (PA1, PA2, PA3, PA4).

The wavelength-selective reflector (310) reflects light that falls within a predetermined wavelength band corresponding to each pixel area (PA1, PA2, PA3, PA4) among the light incident on the display surface. In addition, the wavelength-selective reflector (310) can absorb or transmit the remaining light that does not fall within a predetermined wavelength band corresponding to each pixel area (PA1, PA2, PA3, PA4) among the light incident on the display surface.

For example, if each unit pixel is composed of first, second, third and fourth pixel areas (PA1, PA2, PA3, PA4) that emit red, green, blue and white light, respectively, the wavelength selective reflector (310) may include first, second, third and fourth wavelength reflection areas (311, 312, 313, 314) corresponding to different colors.

The first wavelength reflection area (311) is arranged on the first color filter (210) that transmits light of the first wavelength band corresponding to the first color, corresponds to the non-effective area (NEA) of the first pixel area (PA1), and reflects light of the first wavelength band among light incident on the display panel (100). This first wavelength reflection area (311) overlaps with the pixel circuit (PC) arranged in the non-effective area (NEA) of the first pixel area (PA1).

The second wavelength reflection area (312) is arranged on the second color filter (220) that transmits light of the second wavelength band corresponding to the second color, corresponds to the non-effective area (NEA) of the second pixel area (PA2), and reflects light of the second wavelength band among the light incident on the display panel (100). This second wavelength reflection area (312) overlaps the pixel circuit (PC) arranged in the non-effective area (NEA) of the second pixel area (PA2).

The third wavelength reflection area (313) is arranged on the third color filter (230) that transmits light of the third wavelength band corresponding to the third color, corresponds to the non-effective area (NEA) of the third pixel area (PA3), and reflects light of the third wavelength band among the light incident on the display panel (100). This third wavelength reflection area (313) overlaps the pixel circuit (PC) arranged in the non-effective area (NEA) of the third pixel area (PA3).

The fourth wavelength reflection area (314) is arranged on the fourth color filter (240) that transmits white light, corresponds to the non-effective area (NEA) of the fourth pixel area (PA4), and reflects light incident on the display panel (100). This fourth wavelength reflection area (314) overlaps the pixel circuit (PC) arranged in the non-effective area (NEA) of the fourth pixel area (PA4).

Alternatively, although not shown separately, when each unit pixel is composed of first, second and third pixel areas (PA1, PA2, PA3) that emit red, green and blue light, respectively, the wavelength selective reflector (310) may be composed of first, second and third wavelength reflection areas (311, 312, 313) excluding the fourth wavelength reflection area (314).

Light of a color corresponding to each pixel area (PA) can be reflected by the wavelength-selective reflector (310) and emitted together with the display light. Accordingly, since the display light can be emitted even in the non-effective area (NEA) of each pixel area (PA), the brightness of the display device (10) can be improved.

As illustrated in FIG. 10, the shutter plate (320) of the optical film (300) can correspond to a display area (AA in FIG. 1) including a plurality of pixel areas (PA1, PA2, PA3, PA4).

The shutter plate (320) is placed between the polarizing plate (330 in FIG. 4) and the wavelength selective reflector (310).

The shutter plate (320) delays the light by 0 or λ/2 phase in the display mode, and delays the light by λ/4 phase in the non-display mode. Accordingly, light whose polarization form is maintained by the shutter plate (320) in the display mode can be emitted as display light by passing through the polarizing plate (330) that transmits the linear polarization component.

That is, when the shutter plate (320) is in display mode, light emitted from an organic light-emitting element (OLED) arranged in an effective area (EA) of each pixel area (PA1, PA2, PA3, PA4) and transmitted through a color filter plate (200) as well as external light reflected by a wavelength-selective reflector (310) arranged in an uneffective area (NEA) of each pixel area (PA1, PA2, PA3, PA4) can be emitted as display light to the outside through the shutter plate (320) and polarizing plate (330) in display mode.

On the other hand, when the shutter plate (320) is in the non-display mode, external light incident on the wavelength-selective reflector (310) arranged in the non-effective area (NEA) of each pixel area (PA1, PA2, PA3, PA4) is filtered by the polarizing plate (330) into a linear polarization component in the first polarization direction, and the linear polarization component in the first polarization direction is converted into a circular polarization component in the first rotation direction by a λ/4 phase delay by the shutter plate (320) in the non-display mode. Among the circular polarization components in the first rotation direction, light in a predetermined wavelength range is reflected by the wavelength-selective reflector (310) and is converted into a circular polarization component in the second rotation direction by a λ/2 phase delay. The circular polarization component of the second rotation direction belonging to a predetermined wavelength region is converted into a linear polarization component of the second polarization direction perpendicular to the first polarization direction by being delayed by λ/4 phase by the shutter plate (320) of the non-display mode, and is therefore blocked by the polarizing plate (330).

Fig. 11 is a drawing showing an example of driving when the shutter plate of Fig. 10 is in non-display mode. Fig. 12 is a drawing showing an example of driving when the shutter plate of Fig. 10 is in display mode.

As illustrated in FIGS. 11 and 12, the shutter plate (320) may include first and second electrode layers (321, 322) that face each other, and a liquid crystal layer (323 of FIG. 4) disposed between the first and second electrode layers (321, 322). The liquid crystal layer (323) may be made of a cholesteric liquid crystal material. The shutter plate (320) may further include an alignment film (324) that aligns an initial optical axis of the cholesteric liquid crystal material of the liquid crystal layer (323) in a direction of about 45° with respect to a direction perpendicular to the first and second electrode layers (321, 322).

One of the first and second electrode layers (321, 322) (for example, the first electrode layer (321)) can be connected to a first shutter driving voltage (SDV1; Shutter Driving Voltage) through a third transistor (T3), and the other one (for example, the second electrode layer (322)) can be connected to a second shutter driving voltage (SDV2) having a different voltage level from the first shutter driving voltage (SDV1).

Accordingly, the shutter plate (320) can be driven in either a display mode or a non-display mode by the turn-on-turn-off state of the third transistor (T3).

That is, as illustrated in FIG. 11, when the shutter plate (320) is driven in a non-display mode, the third transistor (T3) is turned off, and the second shutter driving power (SDV2) is supplied to the second electrode layer (322), and the first electrode layer (321) is brought into a floating state by the third transistor (T3) in the turned-off state. Accordingly, since a predetermined electric field is not generated between the first and second electrode layers (321, 322), the cholesteric liquid crystal material of the liquid crystal layer (323) maintains the initial alignment direction by the alignment film (324). Here, the initial alignment direction by the alignment film (324) is a direction tilted at an angle of about 45° with respect to the direction perpendicular to the first and second electrode layers (321, 322).

In this way, the shutter plate (320) in the non-display mode delays the light by λ/4 phase.

On the other hand, as illustrated in FIG. 12, when the shutter plate (320) is driven in the display mode, the third transistor (T3) is turned on, and the second shutter driving power (SDV2) is supplied to the second electrode layer (322), and the first shutter driving power (SDV1) is supplied to the first electrode layer (321) by the third transistor (T3) that is turned on. Accordingly, an electric field corresponding to the voltage difference between the first and second shutter driving power sources (SDV1, SDV2) is generated between the first and second electrode layers (321, 322), so that the optical axis of the cholesteric liquid crystal material of the liquid crystal layer (323) rotates in a direction corresponding to the electric field between the first and second electrode layers (321, 322). Here, the optical axis of the cholesteric liquid crystal material corresponding to the electric field between the first and second electrode layers (321, 322) may be in a direction perpendicular to the first and second electrode layers (321, 322).

In this way, the shutter plate (320) in the display mode delays the light by 0 or λ/2 phase.

Next, the optical path of the display device according to the first embodiment of the present invention will be described.

FIGS. 13, 14 and 15 are diagrams showing examples of cross sections and optical paths in display mode, respectively, along lines I-I', II-II' and III-III' of FIG. 10 according to the first embodiment of the present invention. FIG. 16 is a diagram showing examples of cross sections and optical paths in non-display mode along line I-I' of FIG. 10 according to the first embodiment of the present invention.

As illustrated in FIG. 13, when the display device (10) is in a turn-on state that emits display light corresponding to a video signal, light from an organic light-emitting element (OLED) arranged in an effective area (EA) among each pixel area (PA1) is transmitted through a color filter plate (200) and converted into light of a color corresponding to each pixel area (PA1), and emitted to the outside through a shutter plate (320) and a polarizing plate (330) in the display mode. At this time, since the wavelength-selective reflector (310) of the optical film (300) is arranged in the non-effective area (NEA), the path through which the light from the organic light-emitting element (OLED) is emitted to the outside does not include the wavelength-selective reflector (310).

Since the shutter plate (320) in the display mode delays the light by 0 or λ/2 phase, the light of the organic light-emitting device (OLED) that has passed through the color filter plate (200) maintains its polarization form, and thus the polarizing plate (330) emits the linear polarization component of the light of the organic light-emitting device (OLED) that has passed through the color filter plate (200) and the shutter plate (320) as display light.

In addition, when the display device (10) is in a turn-on state that emits display light corresponding to an image signal, light of a predetermined wavelength range reflected by the wavelength-selective reflector (310) among external light is emitted as display light in the non-effective area (NEA) of each pixel area (PA1). That is, the polarizing plate (330) transmits the linear polarization component among the external light, and the linear polarization component of the external light transmits through the shutter plate (320) of the display mode and reaches the wavelength-selective reflector (310) while maintaining its polarization form, and light belonging to a predetermined wavelength band among the linear polarization components of the external light is reflected by the wavelength-selective reflector (310). At this time, the wavelength band reflected by the wavelength-selective reflector (310) corresponding to each pixel area (PA1) may be similar to or identical to the wavelength band transmitted by the color filter (200) corresponding to each pixel area (PA1).

And, the light reflected by the wavelength selective reflector (310) is emitted as display light through the polarizing plate (330) while maintaining the polarization form by the shutter plate (320) of the display mode.

Accordingly, the display device (10) according to the first embodiment of the present invention can convert external light into display light by means of the wavelength-selective reflector (310) disposed in the non-effective area (NEA), and can emit display light even in the non-effective area (NEA) by means of the shutter plate (320) of the display mode.

In other words, when the display device (10) is in a turn-on state that emits display light corresponding to a video signal, the display light can be emitted from the entire pixel area (PA1) rather than from a portion of each pixel area (PA1), so there is an advantage in that the brightness of the display device (10) can be improved.

As illustrated in FIG. 14, when the display device (10) is in a turn-on state that emits display light corresponding to an image signal, in the effective area (EA) of each of the first, second, third, and fourth pixel areas (PA1, PA2, PA3, PA4), light emitted from the organic light-emitting diode (OLED) of each of the first, second, third, and fourth pixel areas (PA1, PA2, PA3, PA4) is converted into red (RED), white (WHITE), green (GREEN), and blue (BLUE) light corresponding to the first, second, third, and fourth pixel areas (PA1, PA2, PA3, PA4) by the color filter plate (200), and then emitted to the outside as display light through the shutter plate (320) and polarizing plate (330) of the display mode.

As illustrated in FIG. 15, when the display device (10) is in a turn-on state that emits display light corresponding to a video signal, in the non-effective areas (NEAs) of each of the first, second, third, and fourth pixel areas (PA1, PA2, PA3, and PA4), red (RED), white (WHITE), green (GREEN), and blue (BLUE) light reflected by the wavelength-selective reflectors (311, 312, 313, and 314) of each of the first, second, third, and fourth pixel areas (PA1, PA2, PA3, and PA4) among the external light is emitted to the outside as display light through the shutter plate (320) and polarizing plate (330) of the display mode.

On the other hand, as illustrated in Fig. 16, when the display device (10) is in a turn-off state that does not emit display light corresponding to the image signal, the shutter plate (320) is driven in a non-display mode to delay the light by λ/4 phase.

At this time, among the external light incident on the non-effective area (NEA) of each pixel area (PA1), the linear polarization component passes through the polarizing plate (330) and is converted into a circular polarization component by the shutter plate (320) of the non-display mode that delays the light by λ/4 phase. Then, among the circular polarization components by the shutter plate (320), the light of the wavelength band corresponding to each pixel area (PA1) is reflected by the wavelength-selective reflector (310) arranged in the non-effective area (NEA) of each pixel area (PA1) and is delayed by λ/2 phase by the reflection. Accordingly, the light reflected by the wavelength-selective reflector (310) becomes a circular polarization component having a rotational direction opposite to that of the light incident on the wavelength-selective reflector (310) from the shutter plate (320). Accordingly, the light reflected by the wavelength selective reflector (310) is converted into a linear polarization component in a polarization direction perpendicular to the transmission direction of the polarizing plate (330) by the shutter plate (320) of the non-display mode, thereby being blocked by the polarizing plate (330).

In addition, since the organic light-emitting diode (OLED) arranged in the effective area (EA) of each pixel area (PA1) does not emit light, no display light is emitted from the effective area (EA) of each pixel area (PA1). At this time, external light reflected from the effective area (EA) of each pixel area (PA1) is also blocked by the shutter plate (320) and polarizing plate (330) in the non-display mode.

As described above, the display device (10) according to the first embodiment of the present invention has a wavelength-selective reflector (310) that corresponds to the non-display area (NEA) and reflects light of a wavelength band corresponding to each pixel area (PA1, PA2, PA3, PA4), and a shutter plate (320) of a display mode that delays the light by 0 or λ/2 phase. Accordingly, the display device (10), when in a turn-on state that emits display light, can emit external light reflected by the wavelength-selective reflector (310) of the non-display area (NEA) together with light of an organic light-emitting element (OLED) emitted from the effective area (EA) of each pixel area (PA1, PA2, PA3, PA4) as display light. That is, since display light can be emitted even in the non-display area (NEA) of each pixel area (PA1, PA2, PA3, PA4) by using external light, there is an advantage in that the brightness of the display device can be improved.

In addition, since the display device (10) according to the first embodiment of the present invention has a shutter plate (320) and a polarizing plate (330) of a non-display mode that delays light by a λ/4 phase, it can prevent external light reflection in a turn-off state when display light is not emitted. That is, external light can be prevented from being reflected in the non-effective area (NEA) of each pixel area (PA) of the display panel (100) by the wavelength-selective reflector (310) of the optical film (300). In addition, external light reflection can be prevented from being recognized by the shutter plate (320) and the polarizing plate (330) of the non-display mode. Accordingly, the display device (10) according to one embodiment of the present invention has an advantage of being able to implement display light using external light in a turn-on state, while maintaining a black display surface in a turn-off state. Due to this, there is an advantage in that user discomfort and deterioration of aesthetics can be prevented while having a wavelength-selective reflector (310) that reflects external light.

Meanwhile, the optical film (300) according to the first embodiment of the present invention includes a wavelength selective reflector (310) placed between a color filter plate (200) and a shutter plate (320).

However, if the condition that the electric field by the first and second electrode layers (321, 322) in the shutter plate (320) maintains an influence on the liquid crystal layer (323) and the wavelength-selective reflector (310) is placed between the liquid crystal layer (323) and the display panel (100) is achieved, the wavelength-selective reflector (310) may be placed in a layer other than under the shutter plate (320).

FIG. 17 is a diagram showing an example of a cross-section along line I-I' of FIG. 10 according to the second embodiment of the present invention and an optical path in a non-display mode.

As illustrated in FIG. 17, a display device (10') according to the second embodiment of the present invention is identical to the first embodiment except that a wavelength-selective reflector (310) among the optical films (300) is positioned between the first electrode layer (321) of the shutter plate (320) and the liquid crystal layer (323), and therefore, a duplicate description thereof is omitted below.

According to the second embodiment of the present invention, a wavelength selective reflector (310) is placed between the first electrode layer (321) of the shutter plate (320) and the liquid crystal layer (323).

That is, the first electrode layer (321) of the shutter plate (320) may be placed on the color filter plate (200), and the wavelength selective reflector (310) may be placed on the first electrode layer (321).

At this time, the alignment film (324) that implements the initial alignment of the liquid crystal layer (323) is placed on the first electrode layer (321) and the wavelength selective reflector (310), so that it can come into contact with the liquid crystal layer (323) between the first and second electrode layers (321, 322).

Alternatively, although not shown separately, the alignment film (324) may be placed under the second electrode layer (322) or may be placed on both sides of the liquid crystal layer (323) so as to be in contact with the liquid crystal layer (323).

In this way, according to the second embodiment, since the wavelength selective reflector (310) is placed within the shutter plate (320), there is an advantage in that it is protected from external physical or chemical impact.

Meanwhile, the color filter plate (200) of the display device (10) according to the first embodiment of the present invention transmits light of different color wavelength bands and includes first, second, third and fourth color filters (210, 220, 230, 240) corresponding to the first, second, third and fourth pixel areas (PA1, PA2, PA3, PA4), respectively.

In addition, the optical film (300) of the display device (10) according to the first embodiment includes a wavelength-selective reflector (310) corresponding to the non-effective area (NEA) of each of the first, second, third, and fourth pixel areas (PA1, PA2, PA3, PA4). Accordingly, reflection of external light by the pixel circuit (PC) arranged in the non-effective area (NEA) can be prevented by the wavelength-selective reflector (310).

However, the display area (AA of FIG. 2) of the display panel (100) further includes a separation area between the first, second, third and fourth pixel areas (PA1, PA2, PA3, PA4) in addition to the first, second, third and fourth pixel areas (PA1, PA2, PA3, PA4).

That is, referring to the cities of FIGS. 7 and 8, the separation areas between the first, second, third and fourth color filters (210, 220, 230, 240) are generated by the separation areas between the first, second, third and fourth pixel areas (PA1, PA2, PA3, PA4).

For example, when the first, second, third and fourth color filters (210, 220, 230, 240) correspond to pixel areas of each vertical line among a plurality of pixel areas (PA), the spacing area between the first, second, third and fourth color filters (210, 220, 230, 240) may correspond to the spacing area between the vertical lines. In this case, the data line (14), the first driving power line (16) and the reference power line (18) arranged in the spacing area between the vertical lines may not be covered by the color filter plate (200) and the wavelength selective reflector (310).

Accordingly, when the data line (14), the first driving power line (16), and the reference power line (18) are made of metal, there is a problem that the image quality may deteriorate due to vertical light leakage defects caused by external light reflection.

To prevent this, the color filter plate (200) may further include a black matrix placed in the gap area between the first, second, third and fourth color filters (210, 220, 230, 240).

FIG. 18 is a diagram showing an example of a cross-section along line II-II' of FIG. 10 according to a third embodiment of the present invention and an optical path in a non-display mode.

As illustrated in FIG. 18, the display device (10") according to the third embodiment of the present invention is identical to the first embodiment except that the color filter plate (200) further includes a black matrix (250), and therefore, a duplicate description thereof is omitted below.

As illustrated in FIG. 18, according to the third embodiment of the present invention, the color filter plate (200) includes a black matrix (250) positioned between each color filter (210, 220, 230, 240).

Accordingly, external light reflection by vertical signal lines (e.g., data line (14), first driving power line (16), and reference power line (18)) can be blocked by the black matrix (250), so that image quality deterioration can be prevented.

The present invention described above is not limited to the above-described embodiments and the attached drawings, and it will be apparent to a person skilled in the art to which the present invention pertains that various substitutions, modifications, and changes are possible within a scope that does not depart from the technical spirit of the present invention.

10, 10', 10": Display device 100: Display panel
200: Color filter plate 300: Optical film
PA: pixel area OLED: organic light-emitting diode
PC: Pixel Circuit
110: Circuit Array 120: Element Array
130: Sealing layer
EA: Valid Area NEA: Invalid Area
310: Wavelength selective reflector 320: Shutter plate
321, 322: First and second electrode layers
323: Liquid crystal layer 324: Alignment film
330: Polarizing plate
210, 220, 230, 240: 1st, 2nd, 3rd, 4th color filters
311, 312, 313, 314: 1st, 2nd, 3rd, 4th wavelength reflection areas
250: Black Matrix

Claims (10)

In an optical film disposed on a display surface from which light of a plurality of pixel areas is emitted among a display panel including a plurality of pixel areas,
A polarizing plate that transmits linear polarization components;
A shutter plate disposed between the polarizing plate and the display panel and delaying light by 0 or λ/2 phase in the display mode and by λ/4 phase in the non-display mode; and
A wavelength-selective reflector is disposed between the display panel and the shutter plate and corresponds to at least a portion of each of the plurality of pixel areas and reflects light belonging to a predetermined wavelength band among light incident on the display surface.
The above plurality of pixel areas include a first pixel area emitting light of a first wavelength band corresponding to a first color, a second pixel area adjacent to the first pixel area and emitting light of a second wavelength band corresponding to a second color different from the first color, and a third pixel area adjacent to one of the first and second pixel areas and emitting light of a third wavelength band corresponding to a third color different from the first and second colors.
An optical film comprising: a first wavelength reflection region arranged in at least a portion of the first pixel area and reflecting light of the first wavelength band among light incident on the display surface and absorbing or transmitting the remaining light; a second wavelength reflection region arranged in at least a portion of the second pixel area and reflecting light of the second wavelength band among light incident on the display surface and absorbing or transmitting the remaining light; and a third wavelength reflection region arranged in at least a portion of the third pixel area and reflecting light of the third wavelength band among light incident on the display surface and absorbing or transmitting the remaining light.
delete In paragraph 1,
Each of the above plurality of pixel areas includes an effective area for emitting light and an ineffective area corresponding to a pixel circuit that drives the element emitting light.
An optical film in which the first, second and third wavelength reflection areas of the wavelength selective reflector are respectively arranged in the non-effective areas of the first, second and third pixel areas.
In paragraph 1,
A color filter plate is interposed between the above display panel and the optical film,
The above color filter plate
A first color filter corresponding to the first pixel area and transmitting light of the first wavelength band;
A second color filter corresponding to the second pixel area and transmitting light of the second wavelength band; and
An optical film including a third color filter corresponding to the third pixel area and transmitting light of the third wavelength band.
In paragraph 4,
The optical films in which the first wavelength band, the second wavelength band and the third wavelength band correspond to red, green and blue, respectively.
In paragraph 5,
The above plurality of pixel areas further include a fourth pixel area adjacent to any one of the first, second and third pixel areas and emitting white light,
An optical film wherein the wavelength-selective reflector is positioned in an ineffective area of the fourth pixel area and further includes a fourth wavelength reflection area that reflects light incident on the display surface.
In paragraph 1,
The above shutter plate
First and second electrode layers which are mutually opposed;
Comprising a liquid crystal layer disposed between the first and second electrode layers,
The liquid crystal layer is an optical film including a cholesteric liquid crystal that changes the optical axis based on the electric field between the first and second electrode layers.
In paragraph 7,
The first electrode layer of the above shutter plate is an optical film disposed on the wavelength selective reflector.
In paragraph 7,
The above wavelength selective reflector is disposed on the first electrode layer of the shutter plate,
An optical film in which the wavelength-selective reflector and the liquid crystal layer are disposed between the first and second electrode layers.
An optical film according to any one of claims 1, 3 to 9; and
A display device including the above display panel.