KR102611355B1 - Quantum dot sheet and backlight unit and display device using the same - Google Patents

Abstract

The backlight unit and display device according to the present invention include a light guide plate, a light source disposed on at least one side of the light guide plate, and a quantum dot sheet that surrounds a corner where the top and side surfaces of the light guide plate meet and covers the top and side surfaces of the light guide plate.
Because the quantum dot sheet surrounds the corners of the light guide plate, light leakage through the corners is minimized, and since even the sides of the light guide plate are surrounded by quantum dot sheets, color deviation of the display can be reduced and high color uniformity can be achieved.
Additionally, the quantum dot sheet can be arranged to cover only the other sides of the light guide plate excluding the side of the light guide plate where the light source is disposed, thereby minimizing the light from the light source that is lost while passing through the quantum dot sheet.

Description

Quantum dot sheet and backlight unit and display device using the same {QUANTUM DOT SHEET AND BACKLIGHT UNIT AND DISPLAY DEVICE USING THE SAME}

The present invention relates to a quantum dot sheet containing a phosphor that excites light of various wavelengths depending on particle size, and a backlight unit and display device using the same.

As modern society gradually develops into an information society and the demand for home appliances and various portable electronic devices increases, the demand for various lightweight and thin display devices is also increasing. Among these, the Liquid Crystal Display Device (LCD) is widely used because it has the advantages of low power operation and excellent image quality.

The liquid crystal display device is a non-emissive type display device and includes a liquid crystal panel and a backlight unit disposed below the liquid crystal panel to provide light. Among these, the backlight unit includes a light source, a light guide plate, a reflector, etc.

Meanwhile, as the number of display contents with excellent resolution increases, customer demand for high-specification display devices capable of high color reproduction is also continuously increasing. In order to implement such high color reproduction display devices, display devices using quantum dot sheets (QD sheets) have recently been developed, and one example is a display device that combines a backlight unit of a liquid crystal display device and a quantum dot sheet. .

These display devices use an LED element that emits blue light or an ultraviolet LED that emits ultraviolet rays as the light source of the backlight unit, allowing the light passing through the light guide plate and quantum dot sheet to be implemented as white light with high color gamut.

Figure 1 is an exploded perspective view of a liquid crystal display device equipped with a backlight unit using a conventional quantum dot sheet.

Referring to FIG. 1, the liquid crystal display device 100 includes a cover bottom 110, a backlight unit 190 disposed on the cover bottom 110, a liquid crystal panel 160 that is a display panel, and an edge of the liquid crystal panel 160. It includes a panel guide 170 that surrounds the and a case top 180 that surrounds the panel guide 170 and is fastened to the cover bottom 110. The cover bottom 110 and case top 180 serve as a case for the liquid crystal display device and store the backlight unit 190 and the liquid crystal panel 160.

The liquid crystal panel 160 is a display panel disposed above the backlight unit 190 and displays an image by receiving light from the backlight unit. Specifically, the liquid crystal panel 160 includes a first substrate 161 and a second substrate 163 facing each other side by side with a liquid crystal layer interposed therebetween. Generally, a thin film transistor is disposed on the first substrate 161, and a color filter is disposed on the second substrate 163. At this time, a printed circuit board 167 may be connected to one side of the liquid crystal panel 160 using a connecting member 165 such as a flexible printed circuit board or a tape carrier package.

The backlight unit 190 includes a light guide plate 130, a lower reflector 120 disposed on the lower surface of the light guide plate 130, a light source 140 disposed on one side of the light guide plate 130, and a light guide plate on which the light source 140 is not disposed. It includes side reflectors 121, 122, and 123 disposed on other sides of 130 and a quantum dot sheet 200 disposed on the upper surface of the light guide plate 130.

An optical member 150 that serves to diffuse or converge light incident from the quantum dot sheet 200 may be additionally disposed on the quantum dot sheet 200. The optical member 150 may include a light collection sheet 151 that improves brightness by concentrating light and a diffusion sheet 152 that diffuses incident light to make the brightness uniform.

Figure 2 is a cross-sectional view in the II' direction of a backlight unit using a conventional quantum dot sheet.

The lower reflector 120 serves to reflect light incident on the light guide plate 130 from the light source 140 toward the front so that the light is emitted to the upper surface of the light guide plate 130. The light guide plate 130 disposed on the lower reflector 120 guides the light incident from the light source 140 and changes the line light source into a surface light source. Additionally, side reflectors 121, 122, and 123 are additionally disposed on the sides of the light guide plate 130 where the light source 140 is not disposed to minimize light leaking to the side portion.

A cold cathode tube, LED (Light Emitting Diode), lamp, etc. may be used as the light source 140, but in the case of the backlight unit 190 to which the quantum dot sheet 200 is applied, the LED element 141 of blue light is mainly used. Blue light (BR) emitted from the LED device 141 is converted into white light (WR) while passing through the quantum dot sheet 200.

Quantum dots included in the quantum dot sheet 200 are nanometer-scale semiconductor materials that absorb excitation light of a specific wavelength and then emit wavelength-converted light. The smaller the quantum dot particle, the shorter the wavelength of light it generates, and the larger the particle, the longer the wavelength of light it generates. Therefore, the quantum dot sheet may include quantum dots of various sizes to display colors such as red light, green light, blue light, and yellow light.

Using these properties, it is possible to express visible light of a desired wavelength by adjusting the size of the quantum dots. Furthermore, various colors can be realized simultaneously using quantum dots of various sizes.

As shown in FIG. 2, the light passing through the small-sized first quantum dot 201 included in the quantum dot sheet 200 is converted into green light, and the light passing through the large-sized second quantum dot 203 is converted into red light. It is converted, and the light passing between the quantum dots 201 and 203 emits blue light. When the three lights of red (R), green (G), and blue (B) that pass through the quantum dot sheet 200 are mixed, they are converted into white light.

However, in the case of this conventional invention, there was a problem in that color deviation occurred between the light (YR) coming out through the side reflectors (121, 122, and 123) and the light (WR) coming out through the quantum dot sheet (200).

In addition, blue light from the blue LED device leaks through the corner 131 where the top and side surfaces of the light guide plate 130 meet, causing a problem of light leakage, such as a bluish phenomenon, near the outside of the display device.

In particular, this bluish phenomenon causes problems with the overall color uniformity of the display device, causing screen defects. This occurs due to an assembly step between the quantum dot sheet 200 disposed on the upper surface of the light guide plate 130 and the side reflectors 121, 122, and 123 disposed on the side of the light guide plate 130.

In order to solve these problems of the prior art, a method was used to compensate for the color deviation of the light passing through the quantum dot sheet 200 using a side reflector 121Y to which a yellow dye was applied.

However, in the case of this method, the degree of color deviation was somewhat reduced compared to the structure using the conventional side reflectors 121, 122, and 123, but the problem was not completely solved. That is, the light (YR) that passed through the yellow side reflector (121Y) was still insufficiently implemented as white light when compared to the light (WR) that passed through the quantum dot sheet (200), resulting in a problem of color deviation.

In addition, there still remained a problem with light leakage, such as a bluish phenomenon, caused by light leaking through the corner portion 131 of the light guide plate 130.

In addition, in the case of the conventional inventions described above, three side reflectors 121, 122, and 123 are attached to the side of the light guide plate 130, so there is a problem of an increase in the unit cost of providing additional reflectors and the occurrence of additional processes.

The present invention is intended to solve the above-mentioned problems, and aims to provide a quantum dot sheet that can minimize the light leakage phenomenon of light leaking through the corner where the top and side surfaces of the light guide plate meet, and a backlight unit and display device to which the quantum dot sheet is applied. Do it as

In addition, the present invention aims to provide a quantum dot sheet that can achieve overall unit cost reduction and process reduction by minimizing screen defects and high color uniformity without arranging side reflectors, and a backlight unit and display device to which the quantum dot sheet is applied. .

Additionally, the present invention aims to provide a quantum dot sheet that can minimize color deviation caused by light emitted through a light guide plate, and a backlight unit and display device to which the quantum dot sheet is applied.

In order to achieve the above object, the present invention provides the following quantum dot sheet and a backlight unit and display device to which the quantum dot sheet is applied.

The backlight unit according to the present invention includes a light guide plate having at least one light-receiving side on which light is incident, a light source and a quantum dot sheet disposed on the light-receiving side of the light guide plate. At this time, the quantum dot sheet surrounds the corner where the top and side surfaces of the light guide plate meet and covers the top and side surfaces of the light guide plate.

Since the quantum dot sheet surrounds the corners of the light guide plate, light leakage through the corners is minimized, and since the sides of the light guide plate are also surrounded by the quantum dot sheets, color deviation of the display can be reduced and high color uniformity can be achieved.

In order to obtain a display with higher brightness, the quantum dot sheet can be arranged to cover only the remaining sides of the light guide plate except for the light-receiving side. This is to minimize loss of light from the light source while passing through the quantum dot sheet.

Additionally, to facilitate bending of the quantum dot sheet that is bent and bonded to the light guide plate, a predetermined radius of curvature is given to the corner where the top and side surfaces of the light guide plate meet.

Specifically, the quantum dot sheet according to the present invention includes a main sheet portion corresponding to the upper surface of the light guide plate, and a wing sheet portion corresponding to the side surface of the light guide plate and extending from each side of the main sheet portion. At this time, in order to obtain a display with high brightness, the wing sheet portion may be extended to correspond only to the side of the light guide plate where the light source is not disposed, that is, the remaining sides excluding the light receiving side of the light guide plate.

In addition, the quantum dot sheet is bent along the boundary of the main sheet portion and the wing sheet portion, and is provided with a bending groove where the base layer is removed along the bending line, and the quantum dot layer corresponding to the bending groove is provided with a cut portion to facilitate bending. I do it.

According to the present invention, color compensation is possible without using a separate side reflector on the light guide plate, so there is no need to add a separate side reflector, which has the effect of reducing the overall component cost and process.

In addition, it has the effect of minimizing light leakage, such as the bluish phenomenon on the outside of the display, caused by light coming out through the corners of the light guide plate of the backlight unit.

In addition, according to the present invention, there is an effect of minimizing the problem of color deviation of the light emitted from the light guide plate, increasing the overall color uniformity of the display device, and increasing the brightness.

Figure 1 is an exploded perspective view of a liquid crystal display device equipped with a backlight unit using a conventional quantum dot sheet.
Figure 2 is a cross-sectional view in the II' direction of a backlight unit using a conventional quantum dot sheet.
Figure 3 is a cross-sectional view in the II' direction of a backlight unit to which a quantum dot sheet is applied according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view taken in the II-II' direction for the same embodiment as FIG. 3.
Figure 5 is an enlarged cross-sectional view of a corner portion of a light guide plate according to another embodiment of the present invention.
Figure 6 is a cross-sectional view in the II' direction of a backlight unit to which a quantum dot sheet is applied according to another embodiment of the present invention.
Figure 7 is a cross-sectional view in the II' direction of a backlight unit to which a quantum dot sheet is applied according to another embodiment of the present invention.
Figure 8 is a plan view of a quantum dot sheet according to an embodiment of the present invention.
Figure 9 is a cross-sectional view showing the detailed layer structure of a quantum dot sheet according to an embodiment of the present invention.
Figure 10 is a plan view of a quantum dot sheet according to another embodiment of the present invention.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. In the drawings, identical reference numerals are used to indicate identical or similar components.

Hereinafter, the “top (or bottom)” of the substrate or the provision or arrangement of any component on the “top (or bottom)” of the substrate means that any component is provided or disposed in contact with the upper (or lower) surface of the substrate. In addition, it is not limited to not including other components between the substrate and any components provided or disposed on (or under) the substrate.

When a component is described as being “connected,” “coupled,” or “connected” to another component, that component may be directly connected or connected to that other component, but there are no other components between each component. It should be understood that may be “interposed” or that each component may be “connected,” “combined,” or “connected” through other components.

Figure 3 is a cross-sectional view in the II-I' direction of a backlight unit to which a quantum dot sheet is applied according to an embodiment of the present invention, and Figure 4 is a cross-sectional view in the II-II' direction of the same embodiment.

The backlight unit 390 according to an embodiment of the present invention is an edge-type light source 340 disposed on the side of the light guide plate 330, and is a light guide plate that guides the light emitted from the light source 340. It includes 330 and a light source 340 disposed on one side of the light guide plate 330.

At this time, the light source 340 may be disposed on only one side of the light guide plate 330, or a plurality of light sources 340 may be disposed on both sides with the light guide plate 330 in between, and the light source 340 may be disposed on the light guide plate ( 330) may be placed on at least one side. Hereinafter, the side of the light guide plate 330 on which the light source 340 is disposed and the light from the light source 340 is incident is referred to as the light-receiving side.

The light source 340 may be composed of an LED assembly in which a plurality of LEDs 341 are arranged on an LED (Light Emitting Diode) printed circuit board (PCB) 342. It is preferable to use a blue LED that emits blue light as the LED 341. At this time, the blue light emitted from the light source is converted to white light as it passes through the quantum dot sheet 300.

The quantum dot sheet 300 surrounds the corner portion 331 where the top and side surfaces of the light guide plate 330 meet, and covers both the top surface of the light guide plate 330 and the side surfaces of the light guide plate 330 where the light source is not disposed. That is, in one embodiment of the present invention, the quantum dot sheet 300 covers all remaining sides of the light guide plate 330 except for the light-receiving side, which is the side of the light guide plate 330 where the light source 340 is disposed. Here, the top surface of the light guide plate 330 refers to the surface from which light from the light source 340 is emitted, and specifically refers to the surface in the direction from the light guide plate to the liquid crystal panel 160 of FIG. 1.

Specifically, the quantum dot sheet 300 is provided with a main sheet portion 305 that covers the upper surface of the light guide plate 330 and a wing sheet portion 307 that covers the side surface of the light guide plate 330, and the main sheet portion 305 and the wing sheet It is bent along the bending line 360 at the boundary of the portion 307 and comes into close contact with the light guide plate 330.

The main sheet portion 305 and the wing sheet portion 307 of the quantum dot sheet 300 are divided into regions and given separate names for convenience of explanation, and are not physically separated from each other but are connected as an integrated piece. In addition, the bending line 360 refers to the boundary between the main sheet portion 305 and the wing sheet portion 307, and does not mean a physical line but a virtual line indicating a bent portion.

An adhesive layer 309 is provided between the side of the light guide plate 330 and the wing sheet portion 307 of the quantum dot sheet 300 to increase adhesion and adhesion between the light guide plate 330 and the quantum dot sheet 300. The quantum dot sheet 300 can be fixed.

The adhesive layer 309 is applied in the form of a liquid or gel to the surface of the light guide plate 330 before the quantum dot sheet 300 is brought into close contact with the side of the light guide plate 330, or is adhered to the surface of the light guide plate 330 in the form of a film or sheet. It can be. The adhesive layer 309 may use a polymer resin such as polyvinyl chloride, polyethylene, polystyrene, polypropylene, polyvinylidene chloride, etc.

In another embodiment, the adhesive layer 309 may be formed in advance as a separate layer on the quantum dot sheet 300. If the adhesive layer 309 is formed on the quantum dot sheet 300 in advance, the additional process of placing the adhesive layer 309 on the light guide plate 330 can be omitted when bending the quantum dot sheet 300 and adhering it to the light guide plate 330. there is.

The adhesive layer 309 may be formed on the entire surface of the quantum dot sheet 300 to improve fixation and adhesion with the light guide plate, but the adhesive layer 309 must be formed to minimize the adhesive surface with the light guide plate 330 to minimize loss of light due to interfacial reflection on the adhesive surface. It is preferable to place only the wing sheet portion 307 of the quantum dot sheet 300.

As shown in FIGS. 3 and 4, the quantum dot sheet 300 is arranged to cover all other sides except the side of the light guide plate 330 where the light source 340 is disposed, that is, the light-receiving side of the light guide plate 330. desirable. In this way, since the quantum dot sheet 300 covers not only the top and sides of the light guide plate 330 but also the corners 331 where the top and sides meet, color uniformity defects and light leakage through the corners 331 can be minimized.

That is, in the case of the prior art, since the quantum dot sheet 300 and the side reflector were disposed only on the top and side surfaces excluding the corners, it was difficult to prevent light leakage through the corners 331, preventing the occurrence of a bluish phenomenon in the display device. There was a problem.

In addition, the white light converted by passing through the quantum dot sheet 300, the light that did not pass through the quantum dot sheet 300 and passed through the edge portion 331, and the light that passed through the side reflectors 121, 122, and 123 are different colors from each other. There was a problem with deviations occurring.

However, in the embodiment according to the present invention, since most of the light emitted passes through the quantum dot sheet 300, the color deviation of the light emitted through the backlight unit is minimized to increase color uniformity and minimize light leakage at the corners. It allows you to

Figure 5 is an enlarged cross-sectional view of the corner portion 331 of the light guide plate 330 according to another embodiment of the present invention, and shows another embodiment of the corner portion 331 of the light guide plate 330.

In the case of the present invention, since the quantum dot sheet 300 surrounds the corner portion 331 of the light guide plate 330, the quantum dot sheet 300 has a shape bent in an L shape at the bending line 360.

At this time, in order to increase the adhesion effect with the quantum dot sheet 300 bent at the corner 331 of the light guide plate 330 and to enable the quantum dot sheet 300 to be easily bent and adhered, the curvature radius of the corner 331 of the light guide plate 331 is adjusted to increase the adhesion effect. The R value can be set to be between 0.5mm and 2.0mm.

If the radius of curvature R is less than 0.5 mm, it is difficult to improve the bending effect of the quantum dot sheet 300 because it is similar to the natural radius of curvature R formed in the light guide plate 330. In addition, when the radius of curvature R exceeds 2.0 mm, the contact area with the optical members 150 to be additionally disposed on the quantum dot sheet 300 may decrease, thereby reducing the fixing force and adhesion force between them.

In order to create the round corner portion 331 by applying the curvature radius R value to the light guide plate 330, various methods used by those skilled in the art can be used, and it is preferably formed through injection molding.

Figure 6 is a cross-sectional view in the II' direction of a backlight unit to which a quantum dot sheet is applied according to another embodiment of the present invention.

The quantum dot sheet 300 according to this embodiment surrounds the corner portion 331 where the upper surface and the side surface of the light guide plate 330 meet, and includes the light receiving side, which is the upper surface of the light guide plate 330 and the side where the light source 340 is disposed. Covers all sides.

In this way, when the quantum dot sheet 300 covers all of the light-receiving side of the light guide plate 330, blue light that may leak through the edge portion 331 where the upper surface of the light guide plate 330 and the side where the light source 340 meets meets is minimized. Light leakage at the corners 331 can be minimized and high color uniformity can be achieved.

Figure 7 is a cross-sectional view taken in the II' direction of a backlight unit to which a quantum dot sheet is applied according to another embodiment of the present invention.

In the embodiment of FIG. 6, the quantum dot sheet 300 is arranged to cover the entire light-receiving side of the light guide plate 330, while in the embodiment of FIG. 7, the quantum dot sheet covers the light source 340 and the light-receiving side of the light guide plate 330. The quantum dot sheet 300 is disposed only on a portion of the light-receiving side of the light guide plate 330 so that the sheets 300 do not overlap each other.

That is, the quantum dot sheet 300 covering the light-receiving side of the light guide plate 330 is preferably disposed so as not to cover the incident surface 333 through which light from the light source 340 is incident on the light guide plate 330. The incident surface 333 of the light guide plate 330 refers to the surface on which most of the light from the light source 340 is incident on the light guide plate 330. The type of light source 340 and the sides of the light source 340 and the light guide plate 330 It can be adjusted appropriately depending on the distance from.

This is to prevent light from the light source 340 from being directly interfered with by the quantum dot sheet 300 when it is incident on the light guide plate 330. In this way, by minimizing the direct incidence of light emitted from the light source 340 into the quantum dot sheet 300, light loss can also be reduced, and a high-brightness display can be obtained.

The case where the thickness of the light guide plate 330 is 3 mm and the thickness of the LED 341 is 1 mm will be described as an example. When the LED 341 is disposed from the lower surface of the light guide plate 330, the quantum dot sheet portion 308 covering the side portion where the light source 340 is disposed extends only to a point corresponding to a height of at least 1 mm or more based on the lower surface of the light guide plate 330. It is preferable that it is arranged and has a length of 2 mm or less.

Figure 8 is a plan view of a quantum dot sheet according to an embodiment of the present invention.

The quantum dot sheet 300 according to an embodiment of the present invention includes a main sheet portion 305 corresponding to the upper surface of the light guide plate 330 and a wing sheet portion 307 corresponding to the side surface of the light guide plate 330. At this time, the main sheet portion 305 and the wing sheet portion 307 are connected to each other to have an integrated structure.

The main sheet portion 305 is preferably provided to match the shape of the upper surface of the light guide plate 330, and generally has a rectangular shape.

The wing sheet portion 307 is provided to extend from each side of the main sheet portion 305. In this embodiment, the wing sheet portion 307 is provided at the light guide plate 330 where the light source 340 of the light guide plate 330 is not disposed. ) is extended to correspond only to the side of the

That is, in the quantum dot sheet 300, the side portion of the main sheet portion 305 that is not provided with the wing sheet portion 307 corresponds to the corner portion of the side of the light guide plate 330 where the light source 340 is disposed. Therefore, in this embodiment, the wing sheet portion 307 extends from three sides of the main sheet portion 305 except for one side.

Among the outer sides exposed to the outside of each wing sheet portion 307, the short sides that are the side sides of the wing sheet portion 307 do not directly contact each other before being bent, but when the wing sheet portion 307 is bent, the short sides are They can come into direct contact with each other.

This is because the quantum dot sheet 300 usually covers the rectangular-shaped light guide plate 330, so when the quantum dot sheet 300 is bent to cover the light guide plate 330, the free surface of the quantum dot sheet 300 that does not contact the light guide plate 330 is This is to prevent it from happening.

When the light guide plate 330 is covered by the quantum dot sheet 300, in the case of the bent quantum dot sheet 300, the short sides of the adjacent wing sheet portions 307 come into contact with each other and are configured to completely surround the light guide plate 330. The quantum dot sheet 300 is bent based on the bending line 360 formed along the boundary between the main sheet portion 305 and the wing sheet portion 307.

Figure 9 is a cross-sectional view showing the detailed layer structure of a quantum dot sheet according to an embodiment of the present invention.

The quantum dot sheet 300 includes quantum dot layers 311 and 313 including quantum dots 301 and 303 of different sizes and a base layer 315 that is a light-transmitting sheet.

The base layer 315 preferably contains a resin with excellent light transmittance, for example, polyethylene terephthalate (PET), polyethylene naphthalate, acrylic resin, polycarbonate, and polystyrene. (Polystyrene), polycarbonate (Polycarbonate: PC), etc. Among these, polyethylene terephthalate (PET) can be widely used because it has excellent transparency, strength, and bendability.

The quantum dot layers 311 and 313 may be provided as a single layer containing multiple types of quantum dots 301 and 303 in one quantum dot layer, but may be provided as a multilayer separated into different layers depending on the size of the quantum dots 301 and 303. It may also be provided as. The quantum dots 301 and 303 may be mixed and dispersed within the quantum dot layers 311 and 313 made of resin. At this time, it is desirable to use a resin that forms the quantum dot layers 311 and 313 with excellent ductility, adhesion, moisture resistance, and permeability. For example, silicone resin, a thermosetting resin, can be used.

When manufacturing the quantum dot sheet 300, the quantum dots 301, 303 may be included on one side of the base layer 315, and the resin that will form the quantum dot layers 311, 313 may be injected and pressed with a roller. However, the manufacturing method This is not limited to this.

In addition, an adhesive layer 309 may be additionally provided on the opposite side of the base layer 315 on which the quantum dot layers 311 and 313 are disposed, preferably on the part of the base layer 315 corresponding to the wing sheet portion 307. An adhesive layer 309 may be provided.

The bending line 360 formed along the boundary between the main sheet portion 305 and the wing sheet portion 307 of the quantum dot sheet 300 is a portion where the base layer 315 has been removed to facilitate bending into an L shape. A bending groove 317 may be provided.

In addition, in order to further facilitate bending at the bending line 360, the quantum dot layers 311 and 313 corresponding to the bending groove 317 are pre-cut with a blade to form a cut portion 319 of a certain depth. can do. The depth of the cut portion 319 is preferably formed to be sufficient to maintain the strength of the quantum dot sheet 300 so that the quantum dot layers 311 and 313 are not broken even when bent.

Figure 10 is a plan view of a quantum dot sheet according to another embodiment of the present invention.

The quantum dot sheet 300 according to the embodiment of Figure 10 covers the main sheet portion 305 that covers the upper surface of the light guide plate 330 and the side of the light guide plate 330, and has wings extending from each side of the main sheet portion 305. Includes a seat portion 307. At this time, the main sheet portion 305 and the wing sheet portion 307 are connected to each other to have an integrated structure.

The quantum dot sheet 300 of this embodiment can be applied to an embodiment that covers all sides of the light guide plate 330, including the top surface of the light guide plate 330.

Among the outer sides exposed to the outside of each wing sheet portion 307, the short sides that are the side sides of the wing sheet portion 307 do not directly contact each other before being bent, but when the wing sheet portion 307 is bent, the short sides are They can come into direct contact with each other.

In this case, the wing sheet portion 307 is provided to extend from all sides of the main sheet portion 305. In the case of the wing sheet portion 307 corresponding to the side portion where the light source 340 is disposed, depending on the embodiment, it is formed to have the same length as the thickness of the side portion, or the wing sheet portion 307 is formed so as not to interfere with the optical path of the light source 340. ) can be formed by reducing the length of the short side.

When the light guide plate 330 is covered by the quantum dot sheet 300, in the case of the bent quantum dot sheet 300, the short sides of the adjacent wing sheet portions 307 come into contact with each other and are configured to completely surround the light guide plate 330. The quantum dot sheet 300 is bent based on the bending line 360 formed along the boundary between the main sheet portion 305 and the wing sheet portion 307.

Quantum dot sheets and backlight units according to embodiments of the present invention can be applied to various display devices. For example, the present invention can be applied without limitation to a display device having a backlight unit to which a quantum dot sheet according to an embodiment of the present invention is applied and a display panel disposed on top of the backlight unit to receive light from the backlight unit and display an image. possible.

Although the above description focuses on the embodiments of the present invention, various changes and modifications can be made at the level of those skilled in the art. Accordingly, it will be understood that such changes and modifications are included within the scope of the present invention as long as they do not depart from the scope of the present invention.

100: liquid crystal display device 110, 350: cover bottom
120: reflector 120, 320: lower reflector
121, 121Y, 122, 123: side reflector 130, 330: light guide plate
140, 340: Light source 141, 341: LED
142, 342: LED PCB 150: Optical member
151: light collecting sheet 152: diffusion sheet
160: liquid crystal panel 161: first substrate
163: second substrate 165: connection member
167: printed circuit board 170: panel guide
180: Case top 190, 390: Backlight unit
131: Corner portion 201, 301: First quantum dot (small size)
203, 303: Second quantum dot (large size) 200, 300: Quantum dot sheet
305: main sheet part 307: wing sheet part
309: Adhesive layer 331: Corner part
333: Light incident surface 360: Bending line
310 (311, 313): Quantum dot layer 315: Base layer
317: bending groove 319: incision

Claims (14)

a light guide plate having at least one light-receiving side on which light is incident;
a light source including a light emitting element and disposed to face the light receiving side of the light guide plate; and
It includes a quantum dot sheet that surrounds a corner where the top surface and the side surface of the light guide plate meet, and covers the top surface and the side surface of the light guide plate,
The quantum dot sheet includes the corner portion of the light-receiving side, extends from the corner portion toward the bottom of the light-receiving side, and is disposed to cover a portion of the light-receiving side,
The end of the quantum dot sheet disposed on the light-receiving side is located above the top of the light-emitting device,
The quantum dot sheet includes a plurality of quantum dots,
The quantum dots are arranged to correspond to the top surface, side surfaces, and corners of the light guide plate,
A backlight unit wherein a vertical thickness of the light emitting element is thinner than a vertical thickness of the light guide plate corresponding to the light-receiving side.
delete delete According to paragraph 1,
A backlight unit provided with an adhesive layer between a side of the light guide plate and the quantum dot sheet.
According to paragraph 1,
The quantum dot sheet is,
A main sheet portion corresponding to the upper surface of the light guide plate,
A backlight unit comprising a wing sheet portion corresponding to a side surface of the light guide plate and extending from each side of the main sheet portion.
According to paragraph 1,
A backlight unit wherein the radius of curvature of the corner where the top and side surfaces of the light guide plate meet is 0.5 mm to 2.0 mm.
delete delete According to clause 5,
A backlight unit wherein the quantum dot sheet includes a base layer and a quantum dot layer.
According to clause 9,
A backlight unit in which an adhesive layer is disposed on one side of the base layer corresponding to the wing sheet portion.
According to clause 9,
A backlight unit provided with a bending groove where the base layer is removed along the boundary of the main sheet portion and the wing sheet portion.
According to clause 11,
A backlight unit wherein the quantum dot layer corresponding to the bending groove is provided with a cut portion.
According to clause 5,
The quantum dot sheet is bent in an L shape at the boundary of the main sheet portion and the wing sheet portion, a backlight unit.
A backlight unit according to claim 1; and
a display panel disposed above the backlight unit and receiving light from the backlight unit to display an image; A display device including a.

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