KR102667252B1 - Flexible Display Device - Google Patents

Abstract

The present invention relates to a flexible display device that improves luminance by improving light efficiency by changing the functional plate located at the bottom of the display panel, thereby enabling stable operation over a long period of time.

Description

Flexible display device {Flexible Display Device}

The present invention relates to a flexible display device in which light efficiency is improved by changing the functional plate located at the bottom of the display panel.

Recently, as we have entered a full-fledged information age, the field of displays that visually express electrical information signals has developed rapidly, and in response to this, various flat panel displays with excellent performance in thinness, lightness, and low power consumption have been developed. Display Device) has been developed and is rapidly replacing the existing cathode ray tube (CRT).

Specific examples of such flat panel displays include Liquid Crystal Display devices (LCD), Plasma Display Panel devices (PDP), Field Emission Display devices (FED), and organic light emitting display devices. (Organic Light Emitting Device: OLED), etc.

Among these, self-luminous display devices, such as organic light emitting displays, are being considered as competitive applications because they do not require a separate light source and are compact and display vivid colors.

Meanwhile, an organic light emitting display device is equipped with an organic light emitting device that self-emits light in each sub-pixel, and the organic light emitting device includes two opposing electrodes and is located between the two electrodes to emit light when transported electrons and holes recombine. This I is provided with a light-emitting layer.

Organic light-emitting devices (such as organic light-emitting diodes) are self-luminous devices that use a thin light-emitting layer between electrodes and do not require a separate light source unit, so organic light-emitting displays including organic light-emitting devices have the advantage of being able to be made into thin films. A typical organic light emitting display device has a structure in which an organic light emitting element connected to a pixel driving circuit is formed on a substrate, and an image is displayed as light emitted from the organic light emitting element passes through a substrate or a polarizing plate.

Since the organic light emitting display device is implemented without a separate light source device, it can be easily implemented as a flexible, bendable, or foldable display device and can be designed in various forms.

Accordingly, display devices such as organic light emitting displays containing self-luminous elements have a wide range of application not only in traditional electronic devices such as TVs, but also in various fields such as automobile dashboards, automobile windshields, mirror displays, and indoor and outdoor billboards. is expanding. At this time, optimization tailored to the usage environment of each display device is necessary.

In particular, a display device attached to a surface with a certain curvature requires flexibility not only in the display panel to reflect the curvature, but also in components added to the top and bottom of the display panel to protect the display panel or for a specific function. .

Meanwhile, display devices applied to windshields of automobiles display displays on transparent glass while maintaining the curvature of the above-described components, so high brightness is required for image visibility in environments with strong natural light. In this case, there is a problem of lifespan deterioration when the display device is continuously used at high brightness, and since high power is required for high brightness, heat generation of the display device due to long-term use of high brightness and high power may be a problem.

The present invention is intended to solve the above-mentioned problems, and relates to a flexible display device that improves luminance by improving light efficiency by changing the functional plate located at the bottom of the display panel, thereby enabling stable operation over a long period of time.

The flexible display device of the present invention improves the brightness of the device by changing the structure, thereby reducing power consumption and increasing the lifespan of high brightness.

A flexible display device according to an embodiment of the present invention includes a substrate, a flexible display panel having an array portion on the substrate, a metal plate located below the rear surface of the substrate and absorbing light coming from a lower side of the flexible display panel, and the flexible display panel. A reflector may be included between the flexible display panel and the metal plate to reflect light coming from a lower side of the flexible display panel toward the array unit.

The metal plate may include a light absorption coating layer on at least one side.

The light absorption coating layer may include at least black resin.

The reflector may be a mirror-finished white sheet.

The reflector and the light-absorbing coating layer provided on the surface of the metal plate facing the reflector may be in contact with each other.

Light exiting the lower side of the flexible display panel may be reflected at the interface between the reflector and the light absorption coating layer.

A transparent support film may be further included between the flexible display panel and the reflector.

A wide angle control film that controls the wide angle may be further included on the upper part of the array unit.

A transparent cover member may be further included on the wide angle control film.

In addition, the flexible display device of the present invention according to another embodiment includes a substrate, a flexible display panel having an array portion on the substrate, and a metal plate located below the rear surface of the substrate and absorbing light coming from a lower side of the flexible display panel. and a reflector between the flexible display panel and the metal plate that reflects light coming out of the lower side of the flexible display panel toward the array unit, and a wide-angle control film on the upper part of the array unit that adjusts the wide angle of the light coming out of the flexible display panel. A transparent cover member may be included on the wide angle control film.

The flexible display device of the present invention has the following effects.

First, by further providing a reflector at the interface where light is absorbed in the flexible display device, the amount of light emitted from the front of the reflector can be improved, thereby improving luminance.

Second, by increasing the front emission amount of the display panel, power consumption for a certain amount of luminance can be reduced, thereby improving the lifespan of the display device through low-power operation.

Third, the amount of heat generated by the display panel can be reduced by reducing power consumption.

Fourth, in devices that require high brightness characteristics, such as automobiles, the amount of light recovery can be increased to meet the high brightness characteristics.

1 is an exploded perspective view showing the flexible display device of the present invention.
Figure 2 is a cross-sectional view of Figure 1
3A to 3C are cross-sectional views according to first to third experimental examples.
4 is a cross-sectional view showing the display panel of the flexible display device of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings. Like reference numerals refer to substantially the same elements throughout the specification. In the following description, if it is determined that a detailed description of technology or configuration related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Additionally, the component names used in the following description were selected in consideration of the ease of writing specifications, and may be different from the component names of the actual product.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining various embodiments of the present invention are illustrative, and the present invention is not limited to the matters shown in the drawings. Like reference numerals refer to like elements throughout this specification. Additionally, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists of', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the plural is included unless specifically stated otherwise.

In interpreting the components included in various embodiments of the present invention, it is interpreted to include a margin of error even if there is no separate explicit description.

In explaining various embodiments of the present invention, when describing positional relationships, for example, 'on top', 'on top', 'on bottom', 'next to', etc. When the positional relationship of parts is described, one or more other parts may be located between the two parts, unless 'immediately' or 'directly' is used.

In explaining various embodiments of the present invention, when explaining temporal relationships, for example, temporal relationships such as 'after', 'after', 'after', 'before', etc. When described, non-contiguous cases may be included unless 'immediately' or 'directly' is used.

In describing various embodiments of the present invention, 'first ~', 'second ~', etc. may be used to describe various components, but these terms are only used to distinguish between identical and similar components. am. Therefore, the component modified as 'first ~' in this specification may be the same as the component modified as 'second ~' within the technical idea of the present invention, unless otherwise specified.

Each of the features in the various embodiments of the present invention can be partially or entirely combined or combined with each other, various technical interconnections and operations are possible, and each of the various embodiments can be implemented independently of each other or together in a related relationship. It may be feasible.

Figure 1 is an exploded perspective view showing the flexible display device of the present invention, and Figure 2 is a cross-sectional view of Figure 1.

1 and 2, a flexible display device according to an embodiment of the present invention includes a substrate, a flexible display panel 200 having an array portion on the substrate, and a rear lower side of the display panel 200. It includes a metal plate 300 that absorbs light coming from the lower side of the display panel 200, and a reflector 400 between the display panel and the metal plate that reflects the light coming from the lower side of the flexible display panel toward the array unit. .

Additionally, in the flexible display device of the present invention, a wide angle adjustment film 150 and a cover member 100 are further provided on the upper side of the display panel 200 where an image appears.

The cover member 100 corresponds to the display surface side viewed by the viewer and is configured to directly apply the viewer's touch action. The area inside the dotted line shown in FIG. 1 is the area where the actual image is projected and becomes the active area (AA), and the outside of the area is the non-display area (NA). The active area (AA) and non-display area (NA) are defined in the same corresponding area on the display panel 200. The cover member 100 is on the display surface through which the viewer sees the image, and is also called a cover window or cover glass in that it transmits the image like a kind of transparent film or glass. The cover member 100 is attached to transmit light emitted from the display panel 200 to the outside and protect the surface of the display panel 200. The cover member 100 is provided with a shielding layer in the non-display area (NA), dividing the active area (AA) into a transparent part and the non-display area (NA) into a shielding part, so that the lower part of the non-display area (NA) has a configuration. This can prevent recognition. The cover member 100 may be made of a material with a high Young's modulus, that is, a material with high hardness, in order to reduce cracks due to external impact. Glass may be a representative material with high hardness, but the thickness of a typical glass substrate (substrate) is 0.5 mm or more, so there is a risk of breaking it when folded or bent. Therefore, when the display device is required to be flexible, such as a flexible, bendable or rollable display device, the material of the cover member 100 should be glass with a thin thickness of 0.1 mm or less or a material with a transmittance of a certain level or more. It should be made of a material with high hardness among transparent plastic substrates.

In this case, the image is projected toward the cover member 100, and the cover member 100 will be placed so that the uppermost surface is on the side the viewer looks at. Located on the uppermost side of the cover member 100, the non-display area (NA) is comprised of a wide-angle control film 150, a display panel 200, and a support film 220 so that the relatively inner components are not visible from the outside. , it can be formed with a larger area than the reflector 400 and the metal plate 300.

Additionally, the wide-angle adjustment film 150 includes a wide-angle adjustment structure to adjust the viewing range of the image displayed on the display panel 200. The wide angle adjustment structure may be provided in the wide angle adjustment film 150 in a trapezoidal pattern with the angle adjusted to suit the desired viewing range. In most cases, the trapezoid-shaped pattern is formed from a light-blocking material. In some cases, the wide-angle adjustment film 150 may be provided in a pattern on the uppermost side of the display panel 200 or the inner surface of the cover member 100 rather than being separately configured.

The display panel 200 includes at least one active area (AA), and in the active area, pixels, which are basic units of display, are arranged in an array. One or more non-active areas (NAs) may be placed around the active area. That is, the non-display area may be adjacent to one or more sides of the display area. The display area and the non-display area may have a shape suitable for the design of an electronic device equipped with the flexible display device.

The display panel 200 is applied to a flexible display device having a curve as shown, and the entire structure can be used in a flexible form by sealing the internal array.

Each pixel within the display area may be associated with a pixel circuit. The pixel circuit may include one or more switching transistors and one or more driving transistors on the backplane of the flexible display panel 200. Each pixel circuit may be electrically connected to a gate line and a data line to communicate with one or more driving circuits, such as a gate driver and a data driver, located in the non-display area. The driving circuit may be implemented as a thin film transistor (TFT) in the non-display area. This driving circuit may be referred to as a gate-in-panel (GIP). In addition, some components, such as the data driver IC, are mounted on a separate printed circuit board 250, such as flexible printed circuit board (FPCB), chip-on-film (COF), tape-carrier-package (TCP), etc. It can be combined with a connection interface (pad/bump, pin, etc.) placed in the non-display area using the signal transmission film 210. The display panel 200 may also include various additional elements for generating various signals or driving pixels in an active area. The additional elements may include an inverter circuit, multiplexer, electro static discharge circuit, etc. Due to the provision of the connection interface disposed in the non-display area of the display panel 200, the lower portion of the non-display area of the display panel 200 may be formed to protrude relatively more. The printed circuit board 250 along with the signal transmission film 210 can be folded toward the rear side of the metal plate 300 to prevent visibility from the cover member 100.

Meanwhile, a functional member (not shown) may be further provided below the wide angle adjustment film 150 and above the display panel 200. Functional members may be provided to reinforce mechanical/mechanical and optical characteristics required for the flexible display device 200. The functional member may also include additional elements associated with functions other than pixel driving. For example, the functional member may include additional elements that provide a touch sensing function, a user authentication function (eg, fingerprint recognition), a multi-level pressure sensing function, a tactile feedback function, etc. Additionally, the functional member may include a polarizer that controls display characteristics (eg, external light reflection, color accuracy, luminance, etc.). The functional member may be attached to the upper surface of the display panel 200 using an adhesive.

Looking at the metal plate 300 of the flexible display device of the present invention with reference to FIG. 2, it uses a heat dissipating metal such as aluminum or aluminum alloy as a metal base layer 300a, and light absorption is present on both surfaces of the metal base layer 300a. It includes coating layers 310a and 310b. Through this, the metal base layer 300a of the metal plate 300, which is a heat dissipating metal component, supports the flexible display panel 200 with high bendability and absorbs heat from its operation from the lower side, thereby increasing the temperature of the flexible display panel 200. can be prevented.

The metal base layer 300a is formed thicker than that of the flexible display device for support and heat dissipation functions, and its thickness is approximately 0.2 mm to 1 mm.

The light absorption coating layers 310a and 310b are provided to absorb light coming from the lower side of the flexible display panel 200 as a remaining light component that does not contribute to display. The light absorption coating layers 310a and 310b are formed to be thinner than the metal base layer 300a with a thickness of 10 μm to less than 0.1 mm, and are made of a material such as black resin. In particular, the light absorption coating layers 310a and 310b are meaningful in that they not only absorb residual light but also prevent light from the rear side of the metal plate 300 from being visible. When constructing a flexible display device by attaching it to glass, etc., light on the back side can be recognized outside the glass, so this light absorption function is important in terms of appearance.

Additionally, the flexible display device of the present invention has a significant feature in that it includes a reflector 400 between the flexible display panel 200 and the metal plate 300.

The reflector 400 is made mainly of white resin such as white pigment or white dye. The reflector 400 is made of a thin sheet material of 0.1 mm or less and is easy to cut and cut, making it different from the metal plate 300 formed by methods such as metal molding. The surface of the reflector 400 is mirror-finished so that residual light that escapes from the bottom of the flexible display panel 200 can be mirror-reflected to the top. That is, the flexible display panel 200 uses the front light emitted from the light emitting device as well as the reflected light reflected from the reflector 400. As a result, light efficiency can be improved by increasing the light recovery amount of the flexible display panel 200. The mirror surface treatment of the reflector 400 is performed on the side of the reflector 400 facing the flexible display panel 200.

The reflector 400 may partially include metal components such as aluminum, silver, gold, or copper, or a nickel or chrome plating layer on the surface through a mirror finish, but the amount of metal components included compared to the white resin is relatively small, It does not affect the sheet characteristics of the metal plate 300 and the other reflector plate 400.

Looking at the manufacturing process, the metal plate 300 is formed as a unit metal plate 300 so that the metal base layer 300a has a surface curved by metal molding to match the curvature required for the flexible display device, and then the metal base layer ( Light absorption coating layers 310a and 310b are formed on both surfaces of 300a). On the other hand, the reflector 400 is manufactured in the form of a thin sheet or film with a thickness of 0.1 mm or less, and is supplied as a unit including a plurality of unit reflectors 400.

In the fastening process, the reflector 400 is cut into unit reflectors 400 from the ledger unit, and the flexibility of the sheet or film makes it easy to attach to the surface of the metal plate 300 having a curved surface in the fastening process.

Compared to a structure formed by stacking a plurality of metal material layers on a metal plate, the flexible display panel 200 of the present invention prevents leakage of residual light through light absorption performed by the light absorption coating layer 310a at the interface between the metal plate 300 and the reflector plate 400. It can be prevented and has the advantage of having more interface reflection. When simply stacking metal material layers, the reflected light is not completely transmitted to the upper part of the flexible display panel 200 and is absorbed by total reflection within the metal material, or some of it may fall into the lower part of the metal plate, resulting in a multi-metal stack arrangement of the metal plate 300. It is not possible to obtain the same light recovery rate as in the flexible display device of the present invention. Specific experimental examples will be described later.

Meanwhile, a transparent support film 220 is further provided between the flexible display panel 200 and the reflector 400 to assist the support function of the flexible display panel 200, and the flexible display panel ( 200), direct contamination of the back surface can be prevented and the heat dissipation effect can be further improved.

The support film 220 is attached to the side (second side) of the substrate of the flexible display panel 200 opposite to the side (first side) where the light emitting device is located. The support film 220 is made of polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethylene ether phthalate, polycarbonate, polyarylate, poly It may be made of a thin film composed of a combination of polyether imide, polyether sulfonate, polyimide, polyacrylate, or other suitable polymers. Other suitable materials that can be used to form the support film 220 may be thin glass, dielectric-shielded metal foil, multilayer polymers, polymer films containing polymer materials in combination with nanoparticles or micro particles, etc. there is. The support film 220 may be thicker than the substrate of the flexible display panel 200 (see 151 in FIG. 4) for support.

When the support film 220 is provided, the back of the flexible display panel 200 is attached to the support film 220, and then a fastening process with the metal plate 300 and the reflector 400 is performed.

Hereinafter, the significance of the light-absorbing coating layer on the surface of the reflector and metal plate of the present invention will be examined with reference to experimental examples.

3A to 3C are cross-sectional views according to first to third experimental examples.

3A to 3C, each experimental example has a wide angle adjustment film 150 and a cover member 100 on the display panel 200, and a transparent support film 220 below the display panel 200. has

The first experimental example is provided by attaching a metal plate 300 to the lower side of the support film 220 and having a metal base layer 300a and light absorption coating layers 310a and 310b on both sides of the support film 220.

The second experimental example is one in which a single metal base layer 300a is provided under the support film 220.

The third experimental example is a metal plate comprising a white glossy sheet reflector 400 below the support film 220, a metal base layer 300a below the support film 220, and light absorption coating layers 310a and 310b on both sides. It is provided by attaching (300).

As shown in Table 1, the measured luminance of the first experimental example was 537 nit, the measured luminance of the second experimental example was 540 nit, and the measured luminance of the third experimental example was 562 nit. Looking at this from the perspective of current consumption at the same luminance, it was confirmed that a reduction in current consumption of 36 mA was possible in the first experimental example compared to the second experimental example.

Among the experimental examples, it can be seen that in the first and second experimental examples, the measured luminance in the second experimental example with a single metal layer is slightly higher than in the first experimental example with a double-sided light-absorbing coating layer, but in reality, Figures 1 and 2 and Similarly, when applying to a display device for automobiles, when the flexible display device was configured according to the first experimental example without a light absorption coating layer, there was a problem in that leakage light escaping from the back side of the flexible display panel was observed.

The inventor of the present invention constructed the flexible display device of the present invention with the structure of the third experimental example to solve the low brightness characteristics and leakage light problems of the first and second experimental examples described above, and the advantages of improving brightness and reducing power consumption are achieved. was able to confirm.

division Measured luminance [nit] First Experimental Example (Metal plate with double-sided light-absorbing coating layer) 537 Second Experimental Example (Single metal plate with metal base layer) 540 Third Experimental Example (Metal plate with reflector + double-sided light absorbing coating layer) 562

Hereinafter, we will look at the specific configuration of the display panel 200 of the flexible display device of the present invention. Figure 4 is a cross-sectional view showing the display panel of the flexible display device of the present invention.

As shown in FIG. 4, the display panel 200 includes a thin film transistor array 152 and an organic light emitting device array 153 stacked on a substrate 151, and a touch sensor unit ( 155) is located. In addition to the touch sensor unit 155, additional elements that provide a user authentication function (e.g., fingerprint recognition), a multi-level pressure detection function, a tactile feedback function, etc. are further added on the organic light emitting element array 153. It can be included.

The thin film transistor array 152 and the organic light emitting element array 153 include one or more thin film transistors (TFT) for each of a plurality of sub-pixels defined in a matrix in the active area (AA) of the substrate 151, and the thin film transistor It is made of connected organic light emitting devices (OLED). It will be described specifically with reference to FIG. 4 .

The substrate 151 supports various components of the display panel 200. The substrate 151 may be formed of a transparent insulating material, such as glass or plastic. When the substrate 151 is made of plastic, it may be referred to as a plastic film or a plastic substrate. For example, the substrate 151 may be in the form of a film containing one selected from the group consisting of polyimide-based polymer, polyester-based polymer, silicone-based polymer, acrylic polymer, polyolefin-based polymer, and copolymers thereof. Among these materials, polyimide is mainly used as a plastic substrate because it can be applied to high-temperature processes and is a coatable material. The substrate (array substrate) is also referred to as a concept including elements and functional layers formed on the substrate 151, such as a switching TFT, a driving TFT connected to the switching TFT, an organic light emitting device connected to the driving TFT, a protective film, etc. .

In some cases, a buffer layer (not shown) may be located on the substrate 151. The buffer layer is a functional layer to protect the thin film transistor (TFT) from impurities such as alkali ions leaking from the substrate 151 or lower layers. The buffer layer may be made of silicon oxide (SiOx), silicon nitride (SiNx), or a multilayer thereof.

The thin film transistor array 152 is a thin film transistor 130 in which a gate electrode 132, a gate insulating film 112, a semiconductor layer 134, an interlayer insulating film 114, and source and drain electrodes 136 and 138 are sequentially arranged. , TFT). The thin film transistor 130 (TFT) is provided in at least one sub-pixel provided in the active area AA on the substrate 151.

The formation order of the semiconductor layer 134 and the gate electrode 132 may be changed.

The semiconductor layer 134 is located at a predetermined location on the substrate 151 or the buffer layer. The semiconductor layer 134 may be made of polysilicon (p-Si), in which case a predetermined region may be doped with impurities. Additionally, the semiconductor layer 134 may be made of amorphous silicon (a-Si), or may be made of various organic semiconductor materials such as pentacene. Furthermore, the semiconductor layer 134 may be made of oxide. The gate insulating film 112 may be formed of an insulating inorganic material such as silicon oxide (SiOx) or silicon nitride (SiNx), or may also be formed of an insulating organic material. The gate electrode 132 is made of various conductive materials, such as magnesium (Mg), aluminum (Al), nickel (Ni), chromium (Cr), molybdenum (Mo), tungsten (W), gold (Au), or alloys thereof. etc. can be formed.

The first interlayer insulating film 114 may be formed of an insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx), or may be formed of an insulating organic material. By selectively removing the first interlayer insulating film 114, a contact hole exposing the source and drain regions may be formed.

The source and drain electrodes 136 and 138 are formed of an electrode material on the first interlayer insulating film 114 in a single-layer or multi-layer shape.

An inorganic protective film 116 and a planarization layer 118 may be positioned on the thin film transistor, covering the source and drain electrodes 136 and 138. The inorganic protective film 116 and the planarization layer 118 protect the thin film transistor and planarize the upper part thereof. The inorganic protective film 116 may be formed of an inorganic insulating film such as silicon nitride (SiNx) or silicon oxide (SiOx), and the planarization layer 118 may be formed of an organic insulating film such as Benzocyclobutene (BCB) or acryl. The inorganic protective film 116 and the planarization layer 118 may each be formed as a single layer or may be composed of double or multiple layers, and in some cases, either one of the two layers may be omitted.

It is referred to as a thin film transistor array 152, including a thin film transistor (130, TFT) provided in each sub-pixel on the substrate 151, an inorganic protective film 116, and a planarization layer 118.

The organic light emitting device (OLED) connected to the thin film transistor (TFT) may have a first electrode 122, an organic light emitting layer 124, and a second electrode 126 sequentially disposed. That is, the organic light emitting device (OLED) includes a first electrode 122 connected to the drain electrode 138 through a connection hole 148 provided in the planarization layer 118 and the inorganic protective film 116. ) may be composed of an organic light-emitting layer 124 located on the organic light-emitting layer 124 and a second electrode 116 located on the organic light-emitting layer 114.

When the display panel 200 is a top emission type in which light is emitted above the second electrode 126, the first electrode 122 may include an opaque conductive material with high reflectivity. At this time, the reflective conductive material included may be, for example, silver (Ag), aluminum (Al), gold (Au), molybdenum (Mo), tungsten (W), chromium (Cr), or alloys thereof. .

The bank 128 opens the light emitting area and is formed in the remaining area excluding the light emitting area. Accordingly, the bank 128 has a bank hole that exposes the first electrode 122 corresponding to the light emitting area. The bank 128 may be made of an inorganic insulating material such as silicon nitride (SiNx) or silicon oxide (SiOx), or an organic insulating material such as BCB, acrylic resin, or imide resin.

The organic light emitting layer 124 is located on the first electrode 122 exposed by the bank 128 . The organic light-emitting layer 124 may include a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer. Additionally, the organic light-emitting layer 124 may be composed of a single light-emitting layer structure that emits one light within a single stack, or may be composed of a multiple stack structure including multiple stacks and each stack including a single light-emitting layer of the same color. It can be configured. In this case, adjacent sub-pixels may be arranged to emit different colors to display various colors. For example, sub-pixels having red, green, and blue light-emitting layers may be arranged side by side or in a triangular shape. In some cases, arrangement of white sub-pixels may be added. In addition, with the arrangement structure of the organic light-emitting layer 124, white can be expressed by stacking multiple stacks including light-emitting layers emitting different colors. When expressing white through a stacked structure, a separate color filter may be added to each sub-pixel.

The second electrode 126 is located on the organic light emitting layer 124. When the display panel 200 is a top emission type, the second electrode 126 is made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The light generated in the organic light emitting layer 124 can be emitted to the upper part of the second electrode 126 by being formed or made of a semi-transparent metal or metal alloy such as MgAg.

In FIG. 4, the organic light emitting device array 153 is an organic light emitting device (OLED) of the first electrode 122, the organic light emitting layer 124, and the second electrode 126 stacked on the thin film transistor array 152. In addition to the layered structure, it may include a capping layer (not shown) on top. The capping layer protects the organic light emitting device (OLED) and helps extract light coming from the second electrode 126.

An encapsulation layer 140 is included on the organic light emitting device array 153. The encapsulation layer 140 prevents oxygen and moisture from penetrating from the outside to prevent oxidation of the light emitting material and electrode material. When an organic light-emitting device (OLED) is exposed to moisture or oxygen, pixel shrinkage, which reduces the light-emitting area, may occur, or dark spots may form within the light-emitting area. The encapsulation layer 140 is an inorganic layer 142, 146 made of glass, metal, aluminum oxide (AlOx), or silicon (Si)-based material, and the stress between each layer due to bending of the display panel 200. It acts as a buffer to alleviate and is formed by an alternating configuration of organic films 144 that enhance planarization performance. Here, the component of the organic layer 144 may be an organic insulating material such as acrylic resin, epoxy resin, polyimide, polyethylene, or silicon oxycarbon (SiOC). At this time, the first and second inorganic films 142 and 146 serve to block penetration of moisture or oxygen, and the organic film 144 serves to flatten the surface of the first inorganic film 142. The reason for forming the encapsulation layer as multiple thin film layers is to make the moisture/oxygen movement path longer and more complicated than a single layer, making it difficult for moisture/oxygen to penetrate into the organic light emitting device array 153.

Although not shown, in some cases, a protective layer is further formed between the organic light emitting device (OLED) and the encapsulation layer 140, so that the sides of the encapsulation layer 140 are peeled off or uneven during the manufacturing process of the encapsulation layer 140. It can perform the function of protecting the encapsulation layer 140 from being affected. In some cases, the encapsulation layer 140 is an essential component of an organic light-emitting device (OLED) that is vulnerable to moisture, so it may be viewed as a component of the organic light-emitting device array 153. FIG. 4 illustrates an organic light emitting device array 153 including an encapsulation layer 140 and an organic light emitting device (OLED).

Meanwhile, the display panel 200 of the present invention further includes a touch sensor unit 155 on the organic light emitting element array 153 to recognize a viewer's (user) touch operation.

The touch sensor units 155 are arranged to cross each other and include a first touch wire 1154 and a second touch wire 1154 (same layer as 1152b), one of which receives a voltage signal and the other of which senses the voltage signal. . The first touch wire 1154 and the second touch wire each have main patterns 1154e (not shown) patterned in the same polygonal or circular shape on the touch insulating film 1158, spaced apart from each other, and adjacent main patterns are provided. For connection purposes, first and second bridge patterns 1154b and 1152b are shown on different layers. In the drawing, the first bridge pattern 1154b is shown formed directly on the organic light-emitting device array 153, but it is not limited thereto, and an insulating film or an insulating material is further provided on the organic light-emitting device array 153. A first bridge pattern 1154b may be provided on the top. The second bridge pattern 1152b is located on the same layer as the main pattern of the second touch wire, that is, on the touch insulating film 1158, and may be formed as one piece. In this case, the main pattern 1154e of the first touch wire 1154 is electrically separated from the second touch wire.

An adhesive layer (not shown) is further provided between the cover member 100 and the touch sensor unit 155 to form a bonded state.

Meanwhile, a first flexible film (not shown) is positioned at one end of the first touch wire 1154 and the second touch wire (same layer as 1152b) for voltage signal application and signal sensing in the touch sensor unit 155. It may be connected to pads (not shown). For example, the touch pads may be located on the same layer as the first bridge pattern 1154b, that is, on top of the organic light emitting device array 153.

To increase the strength and/or rigidity of the display panel 200, one or more support layers (not shown) may be provided on the lower part of the substrate 151, that is, on the side opposite to the display surface. The support layer is attached to the side (second side) opposite to the side (first side) on which the organic light emitting element is located among both sides of the substrate 151. The support layer is polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethylene ether phthalate, polycarbonate, polyarylate, and polyether imide. It can be made of a thin film composed of a combination of polyether imide, polyether sulfonate, polyimide, polyacrylate, or other suitable polymers. Other suitable materials that can be used to form the support layer may be thin glass, dielectrically shielded metal foil, multilayer polymers, polymer films containing polymer materials in combination with nanoparticles or micro particles, etc.

Meanwhile, the support film 220, the reflector 400, and the metal plate 300 of FIG. 1 may be sequentially positioned on the rear surface (lower surface) of the display panel 200.

The flexible display device of the present invention further includes a reflector on the interface side where light is absorbed, thereby improving the amount of light emitted from the front of the reflector, thereby improving brightness.

Additionally, by increasing the amount of emission from the front of the display panel (top side of the display panel), power consumption for a certain amount of luminance can be reduced, thereby improving the lifespan of the display device through low-power operation.

Additionally, the amount of heat generated from the display panel can be reduced by reducing power consumption. This can be expected to increase the lifespan of the display device by preventing damage over time to components included in the display device by reducing the amount of heat generated by the display device.

In devices that require high brightness characteristics, such as automobiles, the flexible display device of the present invention induces upper reflection between the interface between the reflector 400 and the metal plate 300 among the light coming from the bottom of the flexible display panel 200, thereby reducing the amount of remaining light. By increasing the amount of light recovery, it is possible to meet the high brightness characteristics of the device.

Although embodiments of the present specification have been described in detail with reference to the attached drawings, the present specification is not necessarily limited to these embodiments, and various modifications may be made without departing from the technical spirit thereof. Accordingly, the embodiments disclosed in this specification are not intended to limit the technical idea of the present invention, but rather to explain it, and the scope of the technical idea of the present invention is not limited by these embodiments. Each feature of the various embodiments of the present invention can be partially or entirely combined or combined with each other, and can be technically linked and driven in various ways by those skilled in the art, and each embodiment can be performed independently of each other or together in a related relationship. It may be implemented. The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

100: Cover member 150: Wide angle control film
200: (flexible) display panel 210: signal transmission film
220: Support film 250: Source printed circuit board
300: metal plate 300a: metal base layer
310a: first light-absorbing coating layer 310b: second light-absorbing coating layer
400: Reflector

Claims (14)

A flexible display panel having a substrate and an array unit on the substrate;
a metal plate located on the lower side of the substrate and absorbing light coming from the lower side of the flexible display panel; and
a reflector between the flexible display panel and the metal plate that reflects light coming from a lower side of the flexible display panel toward the array unit;
The metal plate includes a metal base layer and a light-absorbing coating layer disposed on both sides of the metal base layer,
The light absorbing coating layer is,
A first light-absorbing coating layer disposed on the entire surface of the metal base layer to face the reflector, and
A flexible display device comprising a second light absorption coating layer disposed on a back surface of the metal base layer, which is opposite to the front surface. According to clause 1,
The light absorption coating layer is a flexible display device that allows light to be invisible to the rear side of the metal plate. According to clause 1,
A flexible display device wherein the light absorption coating layer includes at least black resin. According to clause 1,
A flexible display device in which the reflector is a white sheet with a mirror finish. According to clause 1,
A flexible display device wherein the reflector and the first light absorption coating layer are in contact with each other. According to clause 2,
A flexible display device in which light exiting the lower side of the flexible display panel is reflected at an interface between the reflector and the light absorption coating layer. According to clause 1,
A flexible display device further comprising a transparent support film between the flexible display panel and the reflector. According to clause 1,
A flexible display device further including a wide-angle control film for controlling the wide angle on the upper part of the array unit. According to clause 8,
A flexible display device further comprising a transparent cover member on top of the wide-angle control film. A flexible display panel having a substrate and an array unit on the substrate;
a metal plate located on the lower side of the substrate and absorbing light coming from the lower side of the flexible display panel;
a reflector between the flexible display panel and the metal plate that reflects light coming from a lower side of the flexible display panel toward the array unit;
a wide-angle control film that adjusts the wide angle of light emitted from the flexible display panel on the upper part of the array unit; and
Includes a transparent cover member on top of the wide-angle control film,
The metal plate includes a metal base layer and a light-absorbing coating layer disposed on both sides of the metal base layer,
The light absorbing coating layer is,
A first light-absorbing coating layer disposed on the entire surface of the metal base layer to face the reflector, and
A flexible display device comprising a second light absorption coating layer disposed on a back surface of the metal base layer, which is opposite to the front surface. According to clause 10,
The light absorption coating layer is a flexible display device that allows light to be invisible to the rear side of the metal plate. According to clause 10,
A flexible display device wherein the light absorption coating layer includes at least black resin. According to clause 10,
A flexible display device in which the reflector is a white sheet with a mirror finish. According to clause 10,
A flexible display device wherein the reflector and the first light absorption coating layer are in contact with each other.