Display device

Abstract

A display device is provided. The display device comprises: a display panel; a chip-on-film attached to an end of the display panel; a printed circuit board connected to an end of the chip-on-film and including a connector; a rotating shaft in which the printed circuit board is embedded and which extends along one direction; and a flexible cable, one end of which is connected to the connector portion of the printed circuit board, wherein the connector portion of the printed circuit board does not overlap with the display panel.

Description

Technology Field

[0001] The present invention relates to a display device. Background Technology

[0002] As the information society develops, the demand for display devices for displaying images is increasing in various forms. For example, display devices are being applied to a wide range of electronic devices, such as smartphones, digital cameras, laptop computers, navigation systems, and smart televisions. Display devices may be flat panel display devices, such as Liquid Crystal Display Devices, Field Emission Display Devices, and Organic Light Emitting Display Devices. Among these flat panel display devices, light-emitting display devices include light-emitting elements in which each pixel of the display panel can emit light independently, thereby enabling the display of images without a backlight unit that provides light to the display panel.

[0003] Meanwhile, flexible displays have been commercialized. Flexible displays can reproduce input images on the screen of a display panel formed with plastic OLEDs. Plastic OLEDs are formed on a flexible plastic substrate. Flexible displays allow for the implementation of various designs and offer advantages in portability and durability. Flexible displays can be implemented in various forms, such as bendable displays, foldable displays, and rollable displays. These flexible displays can be applied not only to mobile devices such as smartphones and tablet PCs but also to TVs, automotive displays, and wearable devices, and their application fields are expanding. The problem to be solved

[0004] The problem that the present invention aims to solve is to provide a rollable display device capable of minimizing the radius of a rotating shaft.

[0005] The problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0006] A display device according to one embodiment for solving the above problem comprises: a display panel; a chip-on-film attached to an end of the display panel; a printed circuit board connected to an end of the chip-on-film and including a connector; a rotating shaft in which the printed circuit board is embedded and which extends along one direction; and a flexible cable, one end of which is connected to the connector portion of the printed circuit board, wherein the connector portion of the printed circuit board does not overlap with the display panel.

[0007] A display device according to another embodiment for solving the above problem comprises: a display panel; a chip-on-film attached to an end of the display panel; a printed circuit board connected to an end of the chip-on-film and including a connector; a rotating shaft extending along one direction in which the printed circuit board is embedded; and a flexible cable with one end connected to the printed circuit board, wherein the printed circuit board includes an overlapping portion that overlaps with the rotating shaft and a first protrusion that protrudes outwardly from a first end of the rotating shaft, and the first protrusion includes a first connector portion, and the first connector portion of the printed circuit board does not overlap with the display panel.

[0008] Specific details of other embodiments are included in the detailed description and drawings. Effects of the invention

[0009] According to embodiments of the present invention, the radius of the rotating shaft can be minimized.

[0010] The effects according to the embodiments are not limited to those exemplified above, and a wider variety of effects are included in this specification. Brief explanation of the drawing

[0011] FIG. 1 is a perspective view of a display device according to one embodiment. FIG. 2 is a plan view showing the display panel, chip-on-film, and printed circuit board of the display device according to FIG. 1. Figure 3 is a cross-sectional view taken along the line I-I' of Figure 2. FIG. 4 is a plan view showing one pixel of a display device according to one embodiment. Figure 5 is a cross-sectional view taken along the line II-II' of Figure 4. FIG. 6 is a drawing showing a light-emitting element according to one embodiment. FIGS. 7 and FIGS. 8 are schematic diagrams showing the rolling / unrolling of a display panel of a display device according to FIG. 1. Figure 9 is an enlarged plan view of areas A and B of Figure 1. FIG. 10 is a perspective view of a display device according to another embodiment. FIG. 11 is a plan view showing the display panel, chip-on-film, and printed circuit board of the display device according to FIG. 10. FIG. 12 is a plan view showing the overlapping portion, the first protrusion, and the first flexible cable of FIG. 10. Specific details for implementing the invention

[0012] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0013] When elements or layers are referred to as being "on" another element or layer, this includes cases where another layer or element is interposed directly on or in the middle of another element. Throughout the specification, the same reference numerals refer to the same components. Shapes, sizes, ratios, angles, numbers, etc., disclosed in the drawings for describing embodiments are exemplary and the invention is not limited to the depicted details.

[0014] Specific embodiments will be described below with reference to the attached drawings.

[0015] FIG. 1 is a perspective view of a display device according to one embodiment. FIG. 2 is a plan view showing a display panel, a chip-on-film, and a printed circuit board of the display device according to FIG. 1. FIG. 3 is a cross-sectional view cut along line AA' of FIG. 2.

[0016] Referring to FIGS. 1 to 3, a display device (1) according to one embodiment may include a display panel (100), a rotating shaft (300), and a flexible cable (500).

[0017] The display panel (100) may include long edge portions (LEG1, LEG2) extended along a second direction (DR2) and short edge portions (SEG1, SEG2) extended along a third direction (DR3). The second direction (DR2) and the third direction (DR3) may be intersecting directions.

[0018] The display panel (100) may include a liquid crystal display panel, an organic light-emitting diode display panel, an inorganic light-emitting diode display panel, or a quantum dot display panel. For convenience of explanation, the following description will focus on the case where the display panel (100) is an inorganic light-emitting diode display panel.

[0019] The display panel (100) is provided with a certain degree of flexibility so that rolling (or winding) and unrolling (or unwinding) operations along the outer surface of the aforementioned rotating shaft (300) can be easily and repeatedly performed.

[0020] The display panel (100) may include one side and another side opposite to the one side. One side of the display panel (100) may be a display surface. A specific stacked structure of the display panel (100) is illustrated in FIG. 3.

[0021] As illustrated in FIG. 2, each of the plurality of pixels (PX) of the display device (1) may include a light-emitting region (LA1, LA2, LA3) defined by a pixel defining film and a non-light-emitting region (BA) surrounding the light-emitting region (LA1, LA2, LA3), and may emit light having a predetermined peak wavelength through the light-emitting region (LA1, LA2, LA3). Each of the first to third light-emitting regions (LA1, LA2, LA3) may be a region where light generated from a light-emitting element of the display device is emitted to the outside of the display device.

[0022] The first to third light-emitting regions (LA1, LA2, LA3) can emit light having a predetermined peak wavelength to the outside of the display device. The first light-emitting region (LA1) can emit light of a first color, the second light-emitting region (LA2) can emit light of a second color, and the third light-emitting region (LA3) can emit light of a third color. For example, the first color light may be red light having a peak wavelength in the range of 610 nm to 650 nm, the second color light may be green light having a peak wavelength in the range of 510 nm to 550 nm, and the third color light may be blue light having a peak wavelength in the range of 440 nm to 480 nm, but is not limited thereto.

[0023] As illustrated in FIG. 3, the display device (1) may include a substrate portion (SUB), a display element layer (DEP) on the substrate portion (SUB), and an encapsulating member (ENC) that seals the display element layer (DEP).

[0024] The substrate (SUB) may be made of an insulating material such as a polymer resin. The insulating material may include, for example, polyimide (PI), but is not limited thereto.

[0025] The display element layer (DEP) may include a buffer layer (BF), a thin film transistor layer (TFTL), a light-emitting element layer (EML), a second planarization layer (OC2), a first capping layer (CAP1), a first light-blocking member (BK1), a first wavelength conversion unit (WLC1), a second wavelength conversion unit (WLC2), a light-transmitting unit (LTU), a second capping layer (CAP2), a third planarization layer (OC3), a second light-blocking member (BK2), first to third color filters (CF1, CF2, CF3), a third protection layer (PAS3), and an encapsulation member (ENC).

[0026] A buffer layer (BF) may be disposed on a substrate (100). The buffer layer (BF) may be made of an inorganic film capable of preventing the penetration of air or moisture.

[0027] The thin film transistor layer (TFTL) may include a thin film transistor (TFT), a first pad (PD1), a gate insulating film (GI), an interlayer insulating film (ILD), a first protection layer (PAS1), and a first planarization layer (OC1).

[0028] A thin-film transistor (TFT) can be placed on a buffer layer (BF) and can form a pixel circuit for each of a plurality of pixels.

[0029] A semiconductor layer (ACT) may be provided on a buffer layer (BF). The semiconductor layer (ACT) may overlap with a gate electrode (GE), a source electrode (SE), and a drain electrode (DE). The semiconductor layer (ACT) may be in direct contact with the source electrode (SE) and the drain electrode (DE), and may face the gate electrode (GE) with a gate insulating film (GI) in between.

[0030] The gate electrode (GE) can be placed on top of the gate insulating film (GI). The gate electrode (GE) can overlap with the semiconductor layer (ACT) with the gate insulating film (GI) in between.

[0031] The source electrode (SE) and the drain electrode (DE) may be spaced apart from each other on the interlayer insulating film (ILD). The source electrode (SE) may be in contact with one end of the semiconductor layer (ACT) through a contact hole provided in the gate insulating film (GI) and the interlayer insulating film (ILD). The drain electrode (DE) may be in contact with the other end of the semiconductor layer (ACT) through a contact hole provided in the gate insulating film (GI) and the interlayer insulating film (ILD). The drain electrode (DE) may be connected to the first electrode (AE) of the light-emitting member (EL) through a contact hole provided in the first protective layer (PAS1) and the first planarization layer (OC1). The first pad (PD1) may be placed on the same layer as the source electrode (SE) and the drain electrode (DE), respectively.

[0032] A gate insulating film (GI) may be provided on top of a semiconductor layer (ACT). For example, the gate insulating film (GI) may be placed on top of the semiconductor layer (ACT) and the buffer layer (BF), and may insulate the semiconductor layer (ACT) from the gate electrode (GE). The gate insulating film (GI) may include a contact hole through which a source electrode (SE) passes and a contact hole through which a drain electrode (DE) passes.

[0033] An interlayer insulating film (ILD) may be placed on top of a gate electrode (GE). For example, the interlayer insulating film (ILD) may include a contact hole through which a source electrode (SE) passes and a contact hole through which a drain electrode (DE) passes.

[0034] A first protective layer (PAS1) is provided on top of a thin-film transistor (TFT) to protect the thin-film transistor (TFT). For example, the first protective layer (PAS1) may include a contact hole through which a first electrode (AE) passes.

[0035] The first flattening layer (OC1) is provided on top of the first protection layer (PAS1) to flatten the top of the thin-film transistor (TFT). For example, the first flattening layer (OC1) may include a contact hole through which the first electrode (AE) of the light-emitting member (EL) passes.

[0036] The light-emitting element layer (EML) may include a light-emitting member (EL), a first bank (BNK1), a second bank (BNK2), a first element insulating layer (QPAS1), and a second protective layer (PAS2).

[0037] A light-emitting member (EL) may be provided on a thin-film transistor (TFT). The light-emitting member (EL) may include a first electrode (AE), a second electrode (CE), and a light-emitting element (ED).

[0038] The first electrode (AE) may be provided on the upper part of the first planarization layer (OC1). For example, the first electrode (AE) may be placed on the first bank (BNK1) disposed on the first planarization layer (OC1) to cover the first bank (BNK1). The first electrode (AE) may be placed to overlap with one of the first to third light-emitting regions (LA1, LA2, LA3) defined by the second bank (BNK2). And, the first electrode (AE) may be connected to the drain electrode (DE) of the thin-film transistor (TFT).

[0039] The second electrode (CE) may be provided on top of the first planarization layer (OC1). For example, the second electrode (CE) may be placed on the first bank (BNK1) disposed on the first planarization layer (OC1) to cover the first bank (BNK1). The second electrode (CE) may be placed to overlap with one of the first to third light-emitting regions (LA1, LA2, LA3) defined by the second bank (BNK2). For example, the second electrode (CE) may receive a common voltage supplied to the entire pixel.

[0040] The first element insulating layer (QPAS1) can cover a portion of the first electrode (AE) and a portion of the second electrode (CE) that are adjacent to each other, and can insulate the first electrode (AE) and the second electrode (CE).

[0041] A light-emitting element (ED) may be disposed between a first electrode (AE) and a second electrode (CE) on top of a first planarization layer (OC1). The light-emitting element (ED) may be disposed on a first element insulating layer (QPAS1). One end of the light-emitting element (ED) may be connected to the first electrode (AE), and the other end of the light-emitting element (ED) may be connected to the second electrode (CE). For example, a plurality of light-emitting elements (ED) may include an active layer having the same material and may emit light of the same wavelength range or light of the same color. The light emitted from each of the first to third light-emitting regions (LA1, LA2, LA3) may have the same color. For example, a plurality of light-emitting elements (ED) may emit light of the third color or blue light having a peak wavelength in the range of 440 nm to 480 nm.

[0042] A second bank (BNK2) may be disposed on the first flattening layer (OC1) to define first to third light-emitting regions (LA1, LA2, LA3). For example, the second bank (BNK2) may surround each of the first to third light-emitting regions (LA1, LA2, LA3), but is not limited thereto. The second bank (BNK2) may be disposed in a light-blocking region (BA).

[0043] The second protective layer (PAS2) may be disposed on a plurality of light-emitting members (EL) and a second bank (BNK2). The second protective layer (PAS2) may cover the plurality of light-emitting members (EL) and protect the plurality of light-emitting members (EL).

[0044] The display device (1) may further include a second flattening layer (OC2), a first capping layer (CAP1), a first light-blocking member (BK1), a first wavelength conversion unit (WLC1), a second wavelength conversion unit (WLC2), a light-transmitting unit (LTU), a second capping layer (CAP2), a third flattening layer (OC3), a second light-blocking member (BK2), first to third color filters (CF1, CF2, CF3), a third protective layer (PAS3), and an encapsulation member (ENC).

[0045] The second flattening layer (OC2) is provided on top of the light-emitting element layer (EML) to flatten the top of the light-emitting element layer (EML). The second flattening layer (OC2) may include an organic material.

[0046] The first capping layer (CAP1) may be disposed on the second planarization layer (OC2). The first capping layer (CAP1) may seal the lower surface of the first and second wavelength conversion units (WLC1, WLC2) and the light transmission unit (LTU). The first capping layer (CAP1) may include an inorganic material.

[0047] The first light-blocking member (BK1) may be placed in a light-blocking region (BA) on the first capping layer (CAP1). The first light-blocking member (BK1) may overlap with the second bank (BNK2) in the thickness direction. The first light-blocking member (BK1) can block the transmission of light.

[0048] The first light-blocking member (BK1) may include an organic light-blocking material and a liquid-repellent component.

[0049] The first light-blocking member (BK1) includes a liquid-repellent component, thereby separating the first and second wavelength conversion parts (WLC1, WLC2) and the light-transmitting part (LTU) into corresponding light-emitting regions (LA).

[0050] A first wavelength conversion unit (WLC1) may be disposed in a first light-emitting region (LA1) on a first capping layer (CAP1). The first wavelength conversion unit (WLC1) may be surrounded by a first light-blocking member (BK1). The first wavelength conversion unit (WLC1) may include a first base resin (BS1), a first scatterer (SCT1), and a first wavelength shifter (WLS1).

[0051] The first base resin (BS1) may include a material with a relatively high light transmittance. The first base resin (BS1) may be made of a transparent organic material. For example, the first base resin (BS1) may include at least one of organic materials such as an epoxy resin, an acrylic resin, a cardo resin, and an imide resin.

[0052] The first scatterer (SCT1) may have a different refractive index from the first base resin (BS1) and may form an optical interface with the first base resin (BS1).

[0053] The first wavelength shifter (WLS1) can convert or shift the peak wavelength of incident light to the first peak wavelength. For example, the first wavelength shifter (WLS1) can convert and emit blue light provided by a display device into red light having a single peak wavelength in the range of 610 nm to 650 nm. The first wavelength shifter (WLS1) may be a quantum dot, a quantum rod, or a phosphor. A quantum dot may be a particulate material that emits a specific color as electrons transition from the conduction band to the valence band.

[0054] The light emitted by the first wavelength shifter (WLS1) may have a Full Width of Half Maximum (FWHM) of the emission wavelength spectrum of 45 nm or less, 40 nm or less, or 30 nm or less, and the color purity and color reproduction of the color displayed by the display device may be further improved.

[0055] A portion of the blue light provided by the light-emitting element layer (EML) may pass through the first wavelength conversion unit (WLC1) without being converted into red light by the first wavelength shifter (WLS1). Among the blue light provided by the light-emitting element layer (EML), the light incident on the first color filter (CF1) without being converted by the first wavelength conversion unit (WLC1) may be blocked by the first color filter (CF1). Furthermore, among the blue light provided by the display device, the red light converted by the first wavelength conversion unit (WLC1) may pass through the first color filter (CF1) and be emitted to the outside. Accordingly, the first light-emitting region (LA1) may emit red light.

[0056] The second wavelength converter (WLC2) may be disposed in the second light-emitting region (LA2) on the first capping layer (CAP1). The second wavelength converter (WLC2) may be surrounded by the first light-blocking member (BK1). The second wavelength converter (WLC2) may include a second base resin (BS2), a second scatterer (SCT2), and a second wavelength shifter (WLS2).

[0057] The second base resin (BS2) may include a material with relatively high light transmittance. The second base resin (BS2) may be made of a transparent organic material.

[0058] The second scatterer (SCT2) may have a refractive index different from that of the second base resin (BS2) and may form an optical interface with the second base resin (BS2). For example, the second scatterer (SCT2) may include a light scattering material or light scattering particles that scatter at least a portion of the transmitted light.

[0059] The second wavelength shifter (WLS2) can convert or shift the peak wavelength of incident light to a second peak wavelength different from the first peak wavelength of the first wavelength shifter (WLS1). For example, the second wavelength shifter (WLS2) can convert and emit blue light provided by a display device into green light having a single peak wavelength in the range of 510 nm to 550 nm. The second wavelength shifter (WLS2) may be a quantum dot, a quantum rod, or a phosphor. The second wavelength shifter (WLS2) may include a material of the same nature as the material exemplified in the first wavelength shifter (WLS1).

[0060] The light-transmitting unit (LTU) may be disposed in a third light-emitting region (LA3) on the first capping layer (CAP1). The light-transmitting unit (LTU) may be surrounded by a first light-blocking member (BK1). The light-transmitting unit (LTU) may transmit while maintaining the peak wavelength of the incident light. The light-transmitting unit (LTU) may include a third base resin (BS3) and a third scatterer (SCT3).

[0061] The third base resin (BS3) may include a material with relatively high light transmittance. The third base resin (BS3) may be made of a transparent organic material.

[0062] The third scatterer (SCT3) may have a refractive index different from that of the third base resin (BS3) and may form an optical interface with the third base resin (BS3). For example, the third scatterer (SCT3) may include a light-scattering material or light-scattering particles that scatter at least a portion of the transmitted light.

[0063] The first and second wavelength conversion units (WLC1, WLC2) and the light transmission unit (LTU) are disposed on the light-emitting element layer (EML) through the second planarization layer (OC2) and the first capping layer (CAP1), so that the display device may not require a separate substrate for the first and second wavelength conversion units (WLC1, WLC2) and the light transmission unit (LTU).

[0064] The second capping layer (CAP2) can cover the first and second wavelength conversion sections (WLC1, WLC2), the light transmission section (LTU), and the first light-blocking member (BK1).

[0065] The third flattening layer (OC3) is disposed on top of the second capping layer (CAP2) to flatten the top of the first and second wavelength conversion sections (WLC1, WLC2) and the light transmission section (LTU). The third flattening layer (OC3) may include an organic material.

[0066] The second light-blocking member (BK2) may be placed in a light-blocking region (BA) on the third flattening layer (OC3). The second light-blocking member (BK2) may overlap with the first light-blocking member (BK1) or the second bank (BNK2) in the thickness direction. The second light-blocking member (BK2) can block the transmission of light.

[0067] A first color filter (CF1) may be placed in a first light-emitting region (LA1) on a third planarization layer (OC3). The first color filter (CF1) may be surrounded by a second light-blocking member (BK2). The first color filter (CF1) may overlap with the first wavelength conversion unit (WLC1) in the thickness direction. The first color filter (CF1) may selectively transmit light of a first color (e.g., red light) and block or absorb light of a second color (e.g., green light) and light of a third color (e.g., blue light).

[0068] A second color filter (CF2) may be placed in a second light-emitting region (LA2) on a third planarization layer (OC3). The second color filter (CF2) may be surrounded by a second light-blocking member (BK2). The second color filter (CF2) may overlap with the second wavelength conversion unit (WLC2) in the thickness direction. The second color filter (CF2) may selectively transmit light of a second color (e.g., green light) and block or absorb light of a first color (e.g., red light) and light of a third color (e.g., blue light).

[0069] A third color filter (CF3) may be placed in a third light-emitting region (LA3) on a third planarization layer (OC3). The third color filter (CF3) may be surrounded by a second light-blocking member (BK2). The third color filter (CF3) may overlap with the light-transmitting portion (LTU) in the thickness direction. The third color filter (CF3) may selectively transmit light of a third color (e.g., blue light) and block or absorb light of a first color (e.g., red light) and light of a second color (e.g., green light).

[0070] The first to third color filters (CF1, CF2, CF3) can absorb a portion of the light entering from outside the display device to reduce reflected light caused by external light. Accordingly, the first to third color filters (CF1, CF2, CF3) can prevent color distortion caused by external light reflection.

[0071] The third protective layer (PAS3) can cover the first to third color filters (CF1, CF2, CF3). The third protective layer (PAS3) can protect the first to third color filters (CF1, CF2, CF3).

[0072] The encapsulating member (ENC) may be disposed on the third protective layer (PAS3). For example, the encapsulating member (ENC) may include at least one inorganic film to prevent the penetration of oxygen or moisture. Additionally, the encapsulating member (ENC) may include at least one organic film to protect the display device from foreign substances such as dust.

[0073] Referring again to FIGS. 1 and FIGS. 2, the flexible cable (500) may include a first cable (500a) disposed outside from one end (300a) of the rotating shaft (300), and a second cable (500b) disposed outside from the other end (300b) of the rotating shaft (300). A display device (1) according to one embodiment may further include a plurality of chip-on-films (COFs) connected to the ends of the display panel (100). A driving integrated circuit (IC) may be disposed on each chip-on-film (COF). For example, the driving integrated circuit (IC) may be provided in the form of a driving chip, but is not limited thereto.

[0074] Multiple chip-on-films (COFs) can form a group. For example, three chip-on-films (COFs) can form a group. In FIG. 2, nine chip-on-films (COFs) are illustrated as an example, so three groups (COF_G1, COF_G2, COF_G3) are illustrated. A printed circuit board (PCB) can be connected to the end of each chip-on-film (COF) forming a group (COF_G1, COF_G2, COF_G3).

[0075] As illustrated in FIG. 2, a printed circuit board (PCB) may include an overlapping portion (PCB_P1) that overlaps with a display panel (100), a first protrusion (PCB_P2) connected to the overlapping portion (PCB_P1) and located on the other side of the second direction (DR2) of the overlapping portion (PCB_P1), and a second protrusion (PCB_P3) connected to the overlapping portion (PCB_P1) and located on one side of the second direction (DR2) of the overlapping portion (PCB_P1). A connector portion (CNTP1, CNTP2) may be disposed on each of the protrusions (PCB_P2, PCB_P3). As described below, at least one connector may be disposed on each of the connector portions (CNTP1, CNTP2). For example, a first connector part (CNTP1) may be disposed on the first protrusion (PCB_P2), and a second connector part (CNTP2) may be disposed on the second protrusion (PCB_P3).

[0076] The overlapping portion (PCB_P1) may extend along the second direction (DR2). The overlapping portion (PCB_P1) generally overlaps the display panel (100) in the third direction (DR3), and a portion may protrude outward beyond the short edge (SEG1, SEG2) of the display panel (100).

[0077] The third direction (DR3) width of the overlapping portion (PCB_P1) may be smaller than the width of the protrusions (PCB_P2, PCB_P3), respectively. This is to secure placement space for the connectors placed on the aforementioned protrusions (PCB_P2, PCB_P3).

[0078] Referring again to FIG. 3, a chip-on-film (COF) may be disposed on the first pad (PD1). The chip-on-film (COF) may further include a first chip-on-pad (COF_P1) connected to the first pad (PD1), and a second chip-on-pad (COF_P2) connected to the second pad (PD2) of the printed circuit board (PCB) (in FIG. 3, the overlapping portion (PCB_P1)). An anisotropic conductive film (ACF) may be interposed between the first pad (PD1) and the first chip-on-pad (COF_P1), and between the second pad (PD2) and the second chip-on-pad (COF_P2), respectively. That is, an anisotropic conductive film (ACF) may be interposed between the first pad (PD1) and the first chip-on-pad (COF_P1), and between the second pad (PD2) and the second chip-on-pad (COF_P2), respectively, to be interconnected.

[0079] FIG. 4 is a plan view showing one pixel of a display device according to one embodiment. FIG. 5 is a cross-sectional view taken along the line II-II' of FIG. 4.

[0080] Referring to FIG. 4 and FIG. 5 together with FIG. 2, each of the plurality of pixels (PX) may include first to third subpixels. Each of the first to third subpixels may correspond to each of the first to third light-emitting regions (LA1, LA2, LA3). Each of the light-emitting elements (ED) of the first to third subpixels may emit light through the first to third light-emitting regions (LA1, LA2, LA3).

[0081] Each of the first to third subpixels may emit light of the same color. For example, each of the first to third subpixels may include a light-emitting element (ED) of the same type and may emit light of the third color or blue light. As another example, the first subpixel may emit light of the first color or red light, the second subpixel may emit light of the second color or green light, and the third subpixel may emit light of the third color or blue light.

[0082] Each of the first to third subpixels may include first and second electrodes (AE, CE), a light-emitting element (ED), a plurality of contact electrodes (CTE), and a plurality of second banks (BNK2).

[0083] The first and second electrodes (AE, CE) are electrically connected to a light-emitting element (ED) and can receive a predetermined voltage, and the light-emitting element (ED) can emit light of a specific wavelength range. At least a portion of the first and second electrodes (AE, CE) can form an electric field within the pixel, and the light-emitting element (ED) can be aligned by the electric field.

[0084] For example, the first electrode (AE) may be a pixel electrode separated for each of the first to third subpixels, and the second electrode (CE) may be a common electrode connected in common to the first to third subpixels. Either the first electrode (AE) or the second electrode (CE) may be the anode electrode of the light-emitting element (ED), and the other may be the cathode electrode of the light-emitting element (ED).

[0085] The first electrode (AE) may include a first electrode stem portion (AE1) extending in a first direction (DR1), and at least one first electrode branch portion (AE2) branched from the first electrode stem portion (AE1) and extending in a second direction (DR2).

[0086] The first electrode stem portion (AE1) of each of the first to third subpixels may be spaced apart from the first electrode stem portion (AE1) of an adjacent subpixel, and the first electrode stem portion (AE1) may be positioned on a virtual extension line with the first electrode stem portion (AE1) of an adjacent subpixel in the first direction (DR1). The first electrode stem portion (AE1) of each of the first to third subpixels may receive different signals and may be driven independently.

[0087] The first electrode branch portion (AE2) may be branched from the first electrode stem portion (AE1) and extended in a second direction (DR2). One end of the first electrode branch portion (AE2) may be connected to the first electrode stem portion (AE1), and the other end of the first electrode branch portion (AE2) may be spaced apart from the second electrode stem portion (CE1) facing the first electrode stem portion (AE1).

[0088] The second electrode (CE) may include a second electrode stem portion (CE1) extending in a first direction (DR1), and a second electrode branch portion (CE2) branched from the second electrode stem portion (CE1) and extending in a second direction (DR2). Each of the first to third subpixels may be connected to the second electrode stem portion (CE1) of an adjacent subpixel. The second electrode stem portion (CE1) may extend in the first direction (DR1) and traverse a plurality of pixels. The second electrode stem portion (CE1) may be connected to an outer portion of the display area (DA) or a portion extending in one direction from the non-display area (NDA).

[0089] The second electrode branch (CE2) may be spaced apart from and opposite the first electrode branch (AE2). One end of the second electrode branch (CE2) may be connected to the second electrode stem (CE1), and the other end of the second electrode branch (CE2) may be spaced apart from the first electrode stem (AE1).

[0090] The first electrode (AE) can be electrically connected to the thin-film transistor layer (TFTL) of the display device through the first contact hole (CNT1), and the second electrode (CE) can be electrically connected to the thin-film transistor layer (TFTL) of the display device through the second contact hole (CNT2). For example, the first contact hole (CNT1) can be placed in each of the plurality of first electrode stem portions (AE1), and the second contact hole (CNT2) can be placed in the second electrode stem portion (CE1), but is not limited thereto.

[0091] The second bank (BNK2) may be placed at the boundary between multiple pixels. Multiple first electrode stem portions (AE1) may be spaced apart from each other with respect to the second bank (BNK2). The second bank (BNK2) may extend in the second direction (DR2) and may be placed at the boundary of pixels (SP) arranged in the first direction (DR1). Additionally, the second bank (BNK2) may also be placed at the boundary of pixels (SP) arranged in the second direction (DR2). The second bank (BNK2) may define the boundary of multiple pixels.

[0092] The second bank (BNK2) can prevent the ink from crossing the boundaries of the pixels (SP) when the ink in which the light-emitting elements (ED) are dispersed is sprayed during the manufacture of the display device. The second bank (BNK2) can separate the inks in which different light-emitting elements (ED) are dispersed so that they do not mix with each other.

[0093] A light-emitting element (ED) may be placed between a first electrode (AE) and a second electrode (CE). One end of the light-emitting element (ED) may be connected to the first electrode (AE), and the other end of the light-emitting element (ED) may be connected to the second electrode (CE).

[0094] Multiple light-emitting elements (EDs) may be spaced apart from each other and may be aligned substantially parallel to each other. The spacing between the light-emitting elements (EDs) is not particularly limited.

[0095] A plurality of light-emitting elements (EDs) may include an active layer having the same material and emit light of the same wavelength range or light of the same color. The first to third subpixels may emit light of the same color. For example, a plurality of light-emitting elements (EDs) may emit light of a third color or blue light having a peak wavelength in the range of 440 nm to 480 nm.

[0096] The contact electrode (CTE) may include a first and second contact electrode (CTE1, CTE2). The first contact electrode (CTE1) may cover a first electrode branch (AE2) and a part of the light-emitting element (ED), and may electrically connect the first electrode branch (AE2) and the light-emitting element (ED). The second contact electrode (CTE2) may cover a second electrode branch (CE2) and another part of the light-emitting element (ED), and may electrically connect the second electrode branch (CE2) and the light-emitting element (ED).

[0097] The first contact electrode (CTE1) may be disposed on the first electrode branch (AE2) and extend in the second direction (DR2). The first contact electrode (CTE1) may be in contact with one end of the light-emitting element (ED). The light-emitting element (ED) may be electrically connected to the first electrode (AE) through the first contact electrode (CTE1).

[0098] The second contact electrode (CTE2) may be disposed on the second electrode branch (CE2) and extend in the second direction (DR2). The second contact electrode (CTE2) may be spaced apart from the first contact electrode (CTE1) in the first direction (DR1). The second contact electrode (CTE2) may be in contact with the other end of the light-emitting element (ED). The light-emitting element (ED) may be electrically connected to the second electrode (CE) through the second contact electrode (CTE2).

[0099] The light-emitting element layer (EML) of the display device may be disposed on a thin-film transistor layer (TFTL) and may include first to third element insulating layers (QPAS1, QPAS2, QPAS3).

[0100] A plurality of first banks (BNK1) may be disposed in each of the first to third light-emitting regions (LA1, LA2, LA3). Each of the plurality of first banks (BNK1) may correspond to a first electrode (AE) or a second electrode (CE). Each of the first and second electrodes (AE, CE) may be disposed on the corresponding first bank (BNK1). For example, a plurality of first banks (BNK1) may be disposed on a first planarization layer (OC1), and the side of each of the plurality of first banks (BNK1) may be inclined away from the first planarization layer (OC1). The inclined surface of the first bank (BNK1) may reflect light emitted from the light-emitting element (ED).

[0101] The first electrode stem portion (AE1) may include a first contact hole (CNT1) penetrating the first planarization layer (OC1). The first electrode stem portion (AE1) may be electrically connected to a thin-film transistor (TFT) through the first contact hole (CNT1).

[0102] The second electrode stem portion (CE1) may extend in the first direction (DR1) and may also be placed in a non-luminous region where a light-emitting element (ED) is not placed. The second electrode stem portion (CE1) may include a second contact hole (CNT2) that penetrates the first planarization layer (OC1). The second electrode stem portion (CE1) may be electrically connected to a power electrode through the second contact hole (CNT2). The second electrode (CE) may receive a predetermined electrical signal from the power electrode.

[0103] The first and second electrodes (AE, CE) may include a transparent conductive material. The first and second electrodes (AE, CE) may include a highly reflective conductive material. The first and second electrodes (AE, CE) may each form a structure in which a transparent conductive material and a highly reflective metal are stacked in one or more layers, or may be formed as a single layer including these.

[0104] The first element insulating layer (QPAS1) may be disposed on the first planarization layer (OC1), the first electrode (AE), and the second electrode (CE). The first element insulating layer (QPAS1) may cover a portion of each of the first and second electrodes (AE, CE).

[0105] The first element insulating layer (QPAS1) can protect the first and second electrodes (AE, CE) and can insulate the first and second electrodes (AE, CE) from each other. The first element insulating layer (QPAS1) can prevent the light-emitting element (ED) from being damaged by direct contact with other components.

[0106] A light-emitting element (ED) may be disposed on a first element insulating layer (QPAS1) between a first electrode (AE) and a second electrode (CE). One end of the light-emitting element (ED) may be connected to the first electrode (AE), and the other end of the light-emitting element (ED) may be connected to the second electrode (CE).

[0107] The second element insulating layer (QPAS2) may be partially disposed on the light-emitting element (ED) positioned between the first and second electrodes (AE, CE). The second element insulating layer (QPAS2) may be disposed in the center of the upper surface of the light-emitting element (ED). The third insulating layer (QPAS3) may partially cover the outer surface of the light-emitting element (ED). The third insulating layer (QPAS3) may protect the light-emitting element (ED). The third insulating layer (QPAS3) may cover the outer surface of the light-emitting element (ED).

[0108] The contact electrode (CTE) may include a first and second contact electrode (CTE1, CTE2). The first contact electrode (CTE1) may cover a first electrode branch (AE2) and a part of the light-emitting element (ED), and may electrically connect the first electrode branch (AE2) and the light-emitting element (ED). The second contact electrode (CTE2) may cover a second electrode branch (CE2) and another part of the light-emitting element (ED), and may electrically connect the second electrode branch (CE2) and the light-emitting element (ED).

[0109] The first contact electrode (CTE1) may be disposed on the first electrode branch (AE2) and extend in the second direction (DR2). The first contact electrode (CTE1) may be in contact with one end of the light-emitting element (ED). The light-emitting element (ED) may be electrically connected to the first electrode (AE) through the first contact electrode (CTE1).

[0110] The first contact electrode (CTE1) can directly contact the upper surface of one end of the second element insulating layer (QPAS2).

[0111] The second contact electrode (CTE2) may be disposed on the second electrode branch (CE2) and extend in the second direction (DR2). The second contact electrode (CTE2) may be spaced apart from the first contact electrode (CTE1) in the first direction (DR1). The second contact electrode (CTE2) may be in contact with the other end of the light-emitting element (ED). The light-emitting element (ED) may be electrically connected to the second electrode (CE) through the second contact electrode (CTE2).

[0112] The second contact electrode (CTE2) can directly contact the upper surface of the other end of the second element insulating layer (QPAS2).

[0113] The first contact electrode (CTE1) and the second contact electrode (CTE2) may be disposed on the same layer. The first contact electrode (CTE1) and the second contact electrode (CTE2) may each expose the upper surface of the central portion of the second element insulating layer (QPAS2).

[0114] FIG. 6 is a drawing showing a light-emitting element according to one embodiment.

[0115] Referring to FIG. 6, the light-emitting element (ED) may be a light-emitting diode. For example, the light-emitting element (ED) may have a size in the micrometer or nanometer range and may be an inorganic light-emitting diode containing inorganic materials. The inorganic light-emitting diode may be aligned between two electrodes according to an electric field formed in a specific direction between two electrodes facing each other.

[0116] The light-emitting element (ED) may have a shape that extends in one direction. The light-emitting element (ED) may have a shape such as a rod, wire, or tube. The light-emitting element (ED) may include a first semiconductor layer (111), a second semiconductor layer (113), an active layer (115), an electrode layer (117), and an insulating film (118).

[0117] The first semiconductor layer (111) may be an n-type semiconductor. The second semiconductor layer (113) may be disposed on the active layer (115). Each of the first and second semiconductor layers (111, 113) may be composed of a single layer, but is not limited thereto.

[0118] The active layer (115) may be disposed between the first and second semiconductor layers (111, 113). The active layer (115) may include a material having a single or multiple quantum well structure. If the active layer (115) includes a material having a multiple quantum well structure, a plurality of quantum layers and well layers may be stacked alternately.

[0119] The light emitted from the active layer (115) can be emitted along the length of the light-emitting element (ED) and can also be emitted to both sides. The directionality of the light emitted from the active layer (115) may not be limited.

[0120] The electrode layer (117) may be an ohmic contact electrode. As another example, the electrode layer (117) may be a Schottky contact electrode. The light-emitting element (ED) may include at least one electrode layer (117).

[0121] The insulating film (118) can surround the outer surface of a plurality of semiconductor layers and electrode layers. The insulating film (118) can surround the outer surface of the active layer (115) and can extend in the direction in which the light-emitting element (ED) is extended. The insulating film (118) can protect the light-emitting element (ED).

[0122] The insulating film (118) may include materials having insulating properties, such as silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum nitride (AlN), aluminum oxide (Al2O3), etc.

[0123] The outer surface of the insulating film (118) can be surface treated. When manufacturing a display device, the light-emitting element (ED) can be sprayed onto the electrode in a dispersed state within a predetermined ink and aligned.

[0124] FIGS. 7 and FIGS. 8 are schematic diagrams showing the rolling / unrolling of a display panel of a display device according to FIG. 1.

[0125] Referring to FIGS. 7 and 8, the display panel (100) can be rolled / unrolled in a manner that is rolled and unfolded on the outer surface of the rotating shaft (300). In FIGS. 7 and 8, the display panel (100) is illustrated as being rolled while the rotating shaft (300) rotates in a clockwise direction, but this is not limited thereto, and the display panel (100) may be rolled while the rotating shaft (300) rotates in a counterclockwise direction. For convenience of explanation, the following description will focus on the display panel (100) being rolled while the rotating shaft (300) rotates in a clockwise direction.

[0126] The display panel (100) rolls up and unfolds according to the clockwise / counterclockwise rotation of the rotating shaft (300) because the printed circuit board (MB), which is connected to the display panel (100) via a chip-on-film (COF), is fixed and embedded inside (or hollow) the rotating shaft (300).

[0127] Meanwhile, as described above, since the display panel (100) is rolled / unrolled through the outer surface of the rotating shaft (300), it may be difficult to draw out the flexible cable (500) described above by forming a separate groove on the outer surface of the rotating shaft (300). Therefore, as in one embodiment, the flexible cable (500) must be drawn out through the ends (one end and the other end) of the rotating shaft (300). However, as the display device (1) becomes larger, the number of required flexible cables (500) increases, and the overall size of the display device (1), including the rotating shaft (300), may increase.

[0128] However, as in one embodiment, the ends of groups (COF_G1, COF_G2, COF_G3) of a plurality of chip-on-films (COF) are connected to a single printed circuit board (PCB), and connector portions (CNTP1, CNTP2) that are electrically connected to each group (COF_G1, COF_G2, COF_G3) of chip-on-films (COF) are placed on each protrusion (PCB_P2, PCB_P3) of the printed circuit board (PCB), thereby preventing the overall size of the display device (1) including the rotating shaft (300) from increasing.

[0129] Figure 9 is an enlarged plan view of areas A and B of Figure 1.

[0130] Referring to FIG. 9, a first connector (CNT1) may be disposed in the first connector portion (CNTP1) of the first protrusion (PCT_P2), and a second connector (CNT2) and a third connector (CNT3) may be disposed in the second connector portion (CNTP2) of the second protrusion (PCT_P3). That is, in one embodiment, groups of three chip-on-films (COF) (COF_G1, COF_G2, COF_G3) are exemplified, so the number of connectors in the first connector portion (CNTP1) and the number of connectors in the second connector portion (CNTP2) may be different from each other.

[0131] However, unlike the example, depending on the number of groups of chip-on-films (COFs), the number of connectors in the first connector section (CNTP1) and the number of connectors in the second connector section (CNTP2) may be the same, or the number of connectors in the second connector section (CNTP2) may be greater than the number of connectors in the first connector section (CNTP1).

[0132] Other embodiments are described below.

[0133] FIG. 10 is a perspective view of a display device according to another embodiment. FIG. 11 is a plan view showing a display panel, a chip-on-film, and a printed circuit board of the display device according to FIG. 10. FIG. 12 is a plan view showing an overlapping portion, a first protrusion, and a first flexible cable of FIG. 10.

[0134] Referring to FIGS. 10 to 12, the display device (2) according to the present embodiment is different from the display device (1) according to FIGS. 1 and 2 in that the printed circuit board does not include a second protrusion (PCB_P3 of FIG. 2).

[0135] To explain in more detail, the display device (2) according to the present embodiment may not have a printed circuit board that includes a second protrusion (PCB_P3 in FIG. 2). Accordingly, the first connector part (CNTP1_1) of the first protrusion (PCB_P2) may include three connectors (CNT1, CNT2, CNT3).

[0136] In FIGS. 10 to 12, a case in which the printed circuit board does not include the second protrusion is illustrated, but is not limited thereto, and it is obvious that the printed circuit board may not include the first protrusion and may include only the second protrusion.

[0137] In the case of this embodiment as well, since the display panel (100) is rolled / unrolled through the outer surface of the rotating shaft (300_1), it may be difficult to draw out the aforementioned flexible cable (500a) by forming a separate groove on the outer surface of the rotating shaft (300). Therefore, as in this embodiment, the flexible cable (500a) must be drawn out through the end of the rotating shaft (300_1). However, as the display device (2) becomes larger, the number of required flexible cables (500a) increases, and the overall size of the display device (2), including the rotating shaft (300_1), may increase.

[0138] However, as in the present embodiment, by connecting the ends of groups (COF_G1, COF_G2, COF_G3) of a plurality of chip-on-films (COF) to a single printed circuit board and placing a first connector part (CNTP1), which is electrically connected to each group (COF_G1, COF_G2, COF_G3) of chip-on-films (COF), on a first protrusion (PCB_P2) of the printed circuit board, there is an advantage that the overall size of the display device (2) including the rotating shaft (300_1) can be prevented from increasing.

[0139] Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention may be implemented in other specific forms without changing the technical concept or essential features thereof. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. Explanation of the symbols

[0140] 1: Display device 100: Display panel 300: Rotating shaft 500: Flexible cable

Claims

Claim 1 A display device comprising: a display panel; a chip-on-film attached to an end of the display panel; a printed circuit board connected to an end of the chip-on-film and including a connector portion; a rotating shaft in which the printed circuit board is embedded and which extends along one direction; and a flexible cable, one end of which is connected to the connector portion of the printed circuit board, wherein the printed circuit board includes a protrusion extending from a portion disposed inside the rotating shaft and protruding to the outside of the rotating shaft, and the connector portion of the printed circuit board is disposed on the protrusion and connected to the flexible cable from the outside of the rotating shaft. Claim 2 In claim 1, the display panel is a display device that rolls / unrolls in a manner that rolls and unfolds on the outer surface of the rotating shaft. Claim 3 In claim 2, the rotating shaft includes an internal cut groove, and the display panel is a display device that penetrates the cut groove. Claim 4 In claim 3, the rotating shaft rotates in a predetermined direction, and the display panel is a display device that rolls up and unfolds according to the rotation of the rotating shaft. Claim 5 In claim 4, the rotating shaft comprises a first end and a second end opposite to the first end, and the connector portion is a display device protruding outwardly from either the first end or the second end. Claim 6 In claim 5, the printed circuit board comprises two connector portions, and the two connector portions comprise a first connector portion and a second connector portion, forming a display device. Claim 7 A display device according to claim 6, wherein the first connector portion protrudes outwardly from the first end portion and the second connector portion protrudes outwardly from the second end portion. Claim 8 In claim 7, the first connector part and the second connector part each include at least one connector, and the number of connectors in the first connector part and the number of connectors in the second connector part are different. Claim 9 In claim 1, the display panel comprises: a substrate portion; first banks spaced apart and disposed on the substrate portion; a first electrode and a second electrode spaced apart and disposed on the first bank and covering the first bank; a light-emitting element disposed between the first electrode and the second electrode; a first contact electrode connected to the first electrode and in contact with one end of the light-emitting element; and a second contact electrode connected to the second electrode and in contact with the other end of the light-emitting element. Claim 10 In claim 9, the display panel further comprises the first electrode, a first element insulating layer disposed between the second electrode and the light-emitting element, and a second element insulating layer disposed on the upper surface of the light-emitting element, wherein the first contact electrode is in direct contact with one upper surface of the second element insulating layer, the second contact electrode is in direct contact with the other upper surface of the second element insulating layer, and the first contact electrode and the second contact electrode each expose the upper surface of the central portion of the second element insulating layer. Claim 11 In claim 10, the display panel further comprises a third element insulating layer that integrally covers and contacts the first contact electrode and the second contact electrode. Claim 12 A display device comprising: a display panel; a chip-on-film attached to an end of the display panel; a printed circuit board connected to an end of the chip-on-film and including a connector; a rotating shaft extending along one direction in which the printed circuit board is embedded; and a flexible cable having one end connected to the printed circuit board, wherein the printed circuit board includes an overlapping portion that overlaps with the rotating shaft, and a first protrusion extending from the overlapping portion and protruding outwardly from a first end of the rotating shaft, wherein the first protrusion includes a first connector portion, and the first connector portion of the printed circuit board does not overlap with the display panel. Claim 13 In claim 12, the display panel is a display device that rolls / unrolls in a manner that rolls and unfolds on the outer surface of the rotating shaft. Claim 14 In claim 13, the rotating shaft includes an internal cut groove, and the display panel is a display device that penetrates the cut groove. Claim 15 In claim 14, the rotating shaft rotates in a predetermined direction, and the display panel is a display device that rolls up and unfolds according to the rotation of the rotating shaft. Claim 16 In claim 15, the printed circuit board further comprises a second protrusion that protrudes outwardly from the second end opposite to the first end of the rotating shaft. Claim 17 In claim 16, the second protrusion includes a second connector part, and the first connector part and the second connector part each include at least one connector. Claim 18 In claim 12, a display device in which the width of the overlapping portion is smaller than the width of the first protrusion.

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