KR102534197B1 - Backlight Unit And Display Device Having The Same - Google Patents

Abstract

The present embodiments disclose a backlight unit and a display device including the same. Disclosed is a backlight unit and a display device including the same, which includes a lens unit disposed on one side of a light guide plate, a light source module disposed on one side of the lens unit, and a low refractive index lower than the refractive index of the light guide plate and having a refractive index of 1.3 to 1.5. It includes a refractive resin layer. Through this, it is possible to provide a backlight unit with improved light efficiency and a display device including the same.

Description

Backlight unit and display device including the same {Backlight Unit And Display Device Having The Same}

The present embodiments provide a backlight unit and a display device including the same.

In general, a liquid crystal display (LCD) is a type of flat panel display that displays images by using the electrical and optical properties of liquid crystal, which has intermediate properties between liquid and solid, compared to other displays. It is thin and light, and is used in various applications throughout the industry due to its low power consumption and driving voltage.

On the other hand, since the liquid crystal display device is a non-emissive device that emits light due to external factors, a separate light source is required. Accordingly, a backlight unit equipped with a light source is provided on the rear surface of the liquid crystal panel to emit light toward the front of the liquid crystal display, and the light is diffused while passing through a plurality of optical sheets and condensed into the liquid crystal panel. It is implemented as an identifiable image.

In general, a backlight unit of a liquid crystal display device is divided into an edge-type type and a direct-type type according to an arrangement method of a light emitting lamp used as a light source.

The direct method is a method in which a plurality of lamps are arranged in a row on the rear surface of the liquid crystal panel and irradiated directly to the front surface of the liquid crystal panel. This is to make the light incident on the entire surface of the liquid crystal panel.

Meanwhile, a general backlight unit may include a light source generating light, a light guide plate into which light emitted from the light source is incident, a plurality of optical sheets, and a reflective layer. However, in this case, the thickness of the light guide plate is made thick and the configuration of the backlight unit increases, so there is a problem in that slimming is difficult.

In addition, a backlight unit in which a light guide plate is made of glass and an external member including a reflector is bonded to the light guide plate using an optically transparent adhesive disposed on one surface of the light guide plate has been proposed. However, with the use of the optically transparent adhesive, the critical angle of total reflection, which is a condition for total reflection of light emitted from the light source module inside the light guide plate, is increased, so that the light cannot be totally reflected inside the light guide plate, and most of the light is transmitted in the light incident area.

The present embodiments are to solve the above problems, include a lens unit provided between the light source module and the light guide plate, and utilize a low refractive index resin layer disposed on the rear surface of the light guide plate to slim down and improve light efficiency at the same time. It is intended to provide a backlight unit and a display device including the same.

A backlight unit and a display device including the same according to an embodiment include a light guide plate. Further, a backlight unit and a display device including the same according to an exemplary embodiment include a lens unit positioned on at least one side of the light guide plate. In addition, a backlight unit and a display device including the same according to an embodiment include a light source module disposed on at least one side of the lens unit. Further, a backlight unit and a display device including the same according to an exemplary embodiment include a low refractive resin layer disposed on a rear surface of a light guide plate and having a refractive index lower than that of the light guide plate and having a refractive index of 1.3 to 1.5. In addition, a backlight unit and a display device including the same according to an embodiment include a reflective layer disposed on a rear surface of the low refractive index resin layer.

Also, a backlight unit and a display device including the backlight unit according to another embodiment include a light guide plate. Also, a backlight unit and a display device including the same according to another embodiment include a lens unit positioned on at least one side of the light guide plate. In addition, a backlight unit and a display device including the same according to another embodiment include a light source module disposed on at least one side of the lens unit. Further, a backlight unit and a display device including the same according to another embodiment include a low refractive resin layer disposed on a rear surface of a light guide plate and having a refractive index lower than that of the light guide plate and having a refractive index of 1.3 to 1.5. Also, a backlight unit and a display device including the same according to another embodiment include a reflective layer disposed on a rear surface of the low refractive index resin layer. In addition, a display panel disposed on the light guide plate is included.

The backlight unit and the display device including the same according to the present embodiments can increase the amount of light guided to the light guide plate by narrowing the vertical incident angle of the light emitted from the light source module, thereby improving the light efficiency of the backlight unit and the display device including the same. There is an effect.

1 is a diagram illustrating a backlight unit according to a first embodiment.
2 is a perspective view showing a lens unit according to the first embodiment.
3 is a view comparing vertical and horizontal angles of light incident on a light guide plate when lens units according to Comparative Examples and Examples are applied.
4 is a view showing a display device to which a backlight unit according to the first embodiment is applied.
5 is a view showing a display device according to another embodiment to which the backlight unit according to the first embodiment is applied.
6 is a diagram illustrating a backlight unit according to a second embodiment.
7 is a view showing a display device to which a backlight unit according to a second embodiment is applied.
8 is a graph illustrating a relationship between a low refractive index resin layer and a vertical beam angle of light incident on a light guide plate.
9 is a view showing a display device according to another embodiment to which the backlight unit according to the second embodiment is applied.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments introduced below are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art. Accordingly, the present invention may be embodied in other shapes without being limited to the embodiments described below. And in the drawings, the size and thickness of the device may be exaggerated for convenience. Like reference numbers indicate like elements throughout the specification.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different shapes, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification. The sizes and relative sizes of layers and regions in the drawings may be exaggerated for clarity of explanation.

When an element or layer is referred to as “on” or “on” another element or layer, it includes both cases where another element or layer is intervening as well as directly on another element or layer. do. On the other hand, when an element is referred to as “directly on” or “directly on”, it indicates that no other element or layer is intervening.

The spatially relative terms "below, beneath", "lower", "above", "upper", etc., refer to one element or component as shown in the drawing. It can be used to easily describe the correlation between and other elements or components. Spatially relative terms should be understood as terms that include different orientations of elements in use or operation in addition to the directions shown in the figures. For example, when flipping elements shown in the figures, elements described as “below” or “beneath” other elements may be placed “above” the other elements. Thus, the exemplary term “below” may include directions both below and above.

Also, terms such as first, second, A, B, (a), and (b) may be used in describing the components of the present invention. These terms are only used to distinguish the component from other components, and the nature, sequence, order, or number of the corresponding component is not limited by the term. When an element is described as being “connected,” “coupled to,” or “connected” to another element, that element is or may be directly connected to that other element, but intervenes between each element. It will be understood that may be "interposed", or each component may be "connected", "coupled" or "connected" through other components.

Terminology used herein is for describing the embodiments, and therefore is not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. As used herein, "comprise" and/or "comprising" means that a stated component, step, operation, and/or element is the presence of one or more other components, steps, operations, and/or elements. or do not rule out additions.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

1 is a diagram illustrating a backlight unit according to a first embodiment. Referring to FIG. 1 , the backlight unit 500 according to the first embodiment includes a light guide plate 100, a light source module 120, a lens unit 130, a low refractive index resin layer 140, a reflective layer 150, and a cover member. (150).

Also, the light source module 120 is disposed on the other side of the lens unit 130 . Here, the lens unit 130 may be disposed to contact the light source module 120 . Meanwhile, FIG. 1 shows a configuration in which the lens unit 130 and the light source module 120 are placed in contact, but the present embodiment is not limited thereto, and the lens unit 130 and the light source module 120 are spaced apart from each other. may be placed. That is, in this embodiment, a configuration in which the lens unit 130 is disposed between the light source module 120 and the light guide plate 100 is sufficient.

The light source module 120 may include a light emitting diode chip, a printed circuit board, a housing, and the like, but the type of the light source module 227 according to the present embodiment is not limited thereto, and the light guide plate 100 emits light. Any configuration capable of receiving light is sufficient.

A low refractive index resin layer 140 is disposed on the rear surface of the light guide plate 100 . In this case, the refractive index of the low refractive index resin layer 140 may be lower than that of the light guide plate 100 . Specifically, the refractive index of the low refractive index resin layer 140 may be selected in the range of 1.3 to 1.5.

When the refractive index of the low refractive index resin layer 140 is less than 1.3, since there is no material having a refractive index less than 1.3, it is not possible to select a material for the low refractive index resin layer. In addition, when the refractive index of the low refractive index resin layer 140 exceeds 1.5, the light reaching the boundary between the light guide plate 100 and the low refractive index resin layer 140 is not totally reflected, and thus the amount of light guided through the light guide plate 100 will decrease Therefore, it becomes a cause of lowering light efficiency.

That is, it is sufficient if the refractive index of the low refractive index resin layer 140 according to the present embodiment is in the range of 1.3 to 1.5, and the light guide plate 100 is made of a material having a higher refractive index than the low refractive index resin layer 140. . Here, the light guide plate 100 may be glass, but the present embodiment is not limited thereto.

Meanwhile, a plurality of protrusions 110 are provided between the light guide plate 100 and the low refractive index resin layer 140 . In this case, the plurality of protrusions 110 may be provided to contact one surface of the light guide plate 110 . 1 shows a semicircular shape of the plurality of protrusions 110, but the shape of the plurality of protrusions 110 according to the present embodiment is not limited thereto, and the shape of the plurality of protrusions 110 is the cross-sectional shape of the plurality of protrusions 110. The shape may be a semi-ellipse or polygonal shape.

The plurality of protrusions 110 disperse light incident on the light guide plate 100 to prevent spots from occurring on an image displayed on the display panel due to partial concentration of light, and to adjust the angle of light incident from the light guide plate 100. It can bend vertically.

A reflective layer 150 is disposed on the rear surface of the low refractive index resin layer 140 . Also, a cover member 160 may be disposed on the rear surface of the reflective layer 150 . A sealing member 170 capable of sealing one side of the light guide plate 100 may be provided on one side of the light guide plate 100 .

Meanwhile, a general backlight unit may include a light source module generating light, a light guide plate through which light emitted from the light source module is incident, a plurality of protrusions provided on one surface of the light guide plate, an optical sheet, and a reflective layer. In this case, the light generated from the light source module may move to the entire area of the light guide plate according to the principle of total reflection, and the light may be emitted toward the display panel through the plurality of protrusions, the optical sheet, and the reflective layer. However, in this case, the thickness of the light guide plate is made thick and the configuration of the backlight unit increases, so there is a problem in that slimming is difficult.

In order to solve this problem, glass having a superior light transmittance and thinner thickness than conventional light guide plates is used as a light guide plate, and an exterior member including a reflector is adhered to the light guide plate using an optically transparent adhesive disposed on one side of the light guide plate. of backlight units have been proposed. However, with the use of the optically transparent adhesive, the critical angle of total reflection, which is a condition for total reflection of light emitted from the light source module inside the light guide plate, is increased, so that the light cannot be totally reflected inside the light guide plate, and most of the light is transmitted in the light incident area. That is, although the thickness of the backlight unit was reduced due to the introduction of the optically transparent adhesive, the function of the light guide plate was lost.

In this embodiment, in order to solve the above problems, a separate lens unit 130 is provided between the light guide plate 100 and the light source module 120, and the low refractive index resin layer 140 is provided on the rear surface of the light guide plate 100. ), it is possible to provide a backlight unit having high light efficiency.

Specifically, as shown in FIG. 1 , the backlight unit 500 according to the first embodiment includes a lens unit 130 disposed on one side of the light guide plate 100 and spaced apart from the light guide plate 100 . At this time, an aspherical lens may be applied to the lens unit 130 . An aspherical lens refers to a lens having an aspheric surface, which is not a spherical surface or a flat surface.

Meanwhile, an aspheric area of the lens unit 130 may be disposed to face one side of the light guide plate 100 . Through this, the light emitted from the light source module 120 is condensed through the lens unit 130 having an aspheric area, and the amount of light incident on the light guide plate 100 may be increased.

The structure of the lens unit 130 will be reviewed in detail with reference to FIG. 2 as follows.

2 is a perspective view showing a lens unit according to the first embodiment. Referring to FIG. 2 , the lens unit 130 according to the first embodiment may have a bar shape. Since the lens unit 130 is formed in a bar shape, light emitted by a light source module (not shown) can be easily transferred to a light guide plate (not shown) through the lens unit 130 .

Specifically, since the lens unit 130 is formed in a bar shape, it may be disposed to correspond to an entire side surface of a light guide plate (not shown). Through this, the lens unit 130 may condense the light generated from the light source module (not shown), and the light may be incident on the entire area corresponding to the side surface of the light guide plate (not shown).

Meanwhile, in the case where the lens unit 130 is not in a bar shape and is arranged in an area corresponding to one side surface of a light guide plate (not shown), the light source module is located at the boundary of other lens units disposed adjacent to each other. Light emitted from (not shown) may not be properly transmitted to a light guide plate (not shown), resulting in a hot spot.

In other words, the lens unit 130 according to the present embodiment has a bar-shaped integral structure in an area corresponding to one side surface corresponding to the side surface of the light guide plate (not shown), so that the light source module (not shown) ) may be uniformly incident on one side of the light guide plate (not shown), and thus the probability of occurrence of a hot spot may be reduced.

In addition, the lens unit 130 may include a region in which at least one surface is an aspherical surface. Specifically, grooves 125 of various shapes may be provided in the aspheric area of the lens unit 130 .

For example, as shown in FIG. 2 , the groove 125 of the lens unit 130 may have a curvature in a certain area. In addition, the groove 125 of the lens unit 130 may have a flat surface in a certain area. However, the shape of the groove 125 provided in the lens unit 130 according to the present embodiment is not limited thereto, and the lens unit 130 may include grooves 125 of various shapes. In other words, it is sufficient if at least one surface of the lens unit 130 is configured in an aspherical shape.

Through this, the light emitted from the light source module (not shown) may be condensed through the lens unit 130 . Specifically, since the lens unit 130 has the aspherical groove 125, the light emitted from the light source module (not shown) passes through the lens unit 130 and the vertical angle is narrowed so that the light guide plate (not shown) There is an effect of increasing the amount of incident light.

These effects are reviewed in detail with reference to FIG. 3 as follows. 3 is a view comparing vertical and horizontal angles of light incident on a light guide plate when lens units according to Comparative Examples and Examples are applied. Descriptions according to Comparative Examples and Examples may include the same components as those of the previously described embodiments. A description overlapping with the above-described embodiment may be omitted. Also, the same components have the same reference numerals.

Referring to FIG. 3 , in the backlight unit according to the comparative example, light 131 emitted from the light source module 120 is incident on one side of the light guide plate 100 . At this time, since the vertical angle of the light 131 emitted from the light source module 120 is large, the light 132 that is lost without being incident on the light guide plate 100 is generated. That is, in the backlight unit according to the comparative example, light 132 that is not incident to the light guide plate 100 is lost, and thus light efficiency is lowered.

On the other hand, in the backlight unit according to the embodiment, the light 133 emitted from the light source module 120 passes through the lens unit 130 according to the present embodiment, so that the vertical angle is narrowed and the light 133 is not lost. (100) can be entered. That is, the vertical angle of light 133 is narrowed through the lens unit 130 having an aspheric surface area on the surface facing the light guide plate 100, thereby increasing the amount of light incident on the light guide plate 100 and maximizing light efficiency. There are effects that can be done.

In other words, in the backlight unit according to the embodiment, the lens unit 130 is disposed between the light guide plate 100 and the light source module 120, and one surface of the lens unit 130 facing the light guide plate 100 forms an aspheric area. By including it, the light 133 emitted from the light source module 120 is condensed while passing through the lens unit 130 and enters the light guide plate 100 . Here, since the vertical light directing angle of the light 133 passing through the lens unit 130 is narrowed due to the aspheric area of the lens unit 130, the light 133 can be prevented from spreading, and thus incident on the light guide plate 100. amount of light can be increased.

Next, a review of the display device to which the backlight unit according to the first embodiment as described above is applied is as follows.

4 is a view showing a display device to which a backlight unit according to the first embodiment is applied. A description of the display device may include the same elements as those of the previously described embodiment. A description overlapping with the above-described embodiment may be omitted. Also, the same components have the same reference numerals.

Referring to FIG. 4 , a display device 1000 to which the backlight unit according to the first embodiment is applied includes a backlight unit 500 and a display panel 501 disposed on the backlight unit 500 .

The backlight unit 500 includes a light guide plate 100 , a light source module 120 , a lens unit 130 , a low refractive index resin layer 140 , a reflective layer 150 and a cover member 150 . Also, the display panel 501 includes a lower substrate 210 , an upper substrate 220 , a first polarizing plate 211 and a second polarizing plate 221 .

Specifically, the backlight unit 500 includes the lens unit 130 and the light source module 120 disposed on one side of the light guide plate 100, and the sealing member 170 disposed on the other side of the light guide plate 100. includes In addition, the plurality of protrusions 110 provided on the rear surface of the light guide plate 110, the low refractive index resin layer 140 disposed on the rear surface of the light guide plate 110, the reflective layer 150 disposed on the rear surface of the low refractive index resin layer 140, and It includes a cover member 160 disposed on the rear surface of the reflective layer.

Also, the display panel 501 disposed on the backlight unit 500 may be bonded to the backlight unit 500 by the bonding layer 180 . Also, the lower substrate 210 is disposed on the bonding layer 180 of the display panel 501 , and the upper substrate 220 is disposed on the lower substrate 210 . Also, a first polarizing plate 211 is disposed on the rear surface of the lower substrate 210 and a second polarizing plate 221 is disposed on the upper surface of the upper substrate 220 .

Meanwhile, the first polarizing plate 211 of the display device 1000 according to the present embodiment may be a polarizing plate capable of simultaneously performing the polarization function and the function of the optical sheet. However, the configuration of the display device 1000 according to the present embodiment is not limited thereto, and the first polarizing plate 211 performs only a polarizing function, and a plurality of optical sheets are interposed between the first polarizing plate 211 and the light guide plate 100. It may include a configuration having a.

In the display device 1000 according to the present embodiment, the display panel 501 may be configured by bonding the lower substrate 210 and the upper substrate 220 together. Meanwhile, the display panel 501 according to the present embodiment may be a liquid crystal display panel, the lower substrate 210 is a thin film transistor (TFT) array substrate, and the upper substrate 220 is a color filter array substrate. can Also, although not shown in the drawing, a liquid crystal layer may be interposed between the lower substrate 210 and the upper substrate 220 . Also, a sealing member 225 capable of sealing the lower substrate 210 and the upper substrate 220 may be disposed on at least one side of the lower substrate 210 and the upper substrate 220 .

A common electrode and a pixel electrode are formed in the display panel 501 where the color filter array substrate and the thin film transistor array substrate are bonded together to apply an electric field to the liquid crystal layer, and a data signal applied to the pixel electrode while voltage is applied to the common electrode. When the voltage of the liquid crystal layer is controlled, the liquid crystal of the liquid crystal layer rotates by dielectric anisotropy according to the electric field between the common electrode and the pixel electrode, thereby transmitting or blocking light for each pixel to display characters or images.

In addition, a switching element such as a thin film transistor is individually provided in each pixel to control the voltage of the data signal applied to the pixel electrode for each pixel. First and second polarizers 211 and 221 may be respectively attached to the outside of the display panel 501 configured as described above. The first polarizer 211 polarizes light passing through the backlight unit, and the second polarizer ( 221) polarizes light passing through the display panel 501.

On the other hand, in the backlight unit 500 of the display device 1000 according to the present embodiment, the low refractive index resin layer 140 is disposed on the rear surface of the light guide plate 100, so that the light guide plate 100 and the low refractive index resin layer 140 are connected together. Total reflection occurs at the interface, and the light condensed on the light guide plate 100 may be emitted toward the display panel 501 .

Specifically, the refractive index of the light guide plate 100 according to the present embodiment may be higher than that of the low refractive index resin layer 140 . More specifically, the light guide plate 100 may have a refractive index of 1.51 to 1.65, and the low refractive index resin layer 140 may have a refractive index of 1.35 to 1.5.

In addition, in the display device 1000 according to the present embodiment, an air layer 190 may be provided between the light guide plate 100 and the display panel 501 disposed above the light guide plate 100 . In this case, the refractive index of the air layer may be lower than that of the light guide plate 100 . Specifically, the refractive index of the light guide plate 100 is as described above, and the refractive index of the air layer 190 may be 1.

Meanwhile, in the backlight unit 500 according to the first embodiment, light emitted from the light source module 120 passes through the lens unit 130 and enters the light guide plate 100 . A portion of the light incident on the light guide plate 100 may be emitted in the direction of the display panel 501 immediately after being incident on the light guide plate 100 .

In addition, some of the light incident on the light guide plate 100 through the lens unit 130 has a refractive index lower than that of the light guide plate 100 because the refractive index of the low refractive resin layer 140 and the air layer 190 is lower than that of the light guide plate 100 and the low refractive index. Total reflection may occur at the interface between the refractive resin layer 140 and the interface between the light guide plate 100 and the air layer 190 .

As described above, the light that is totally reflected at the interface between the light guide plate 100 and the low refractive index resin layer 140 and the interface between the light guide plate 100 and the air layer 190 travels inside the light guide plate 100 and toward the display panel 501. can be issued with

In this case, since the plurality of protrusions 110 are provided on one surface of the light guide plate 100 , light can be uniformly distributed over the entire surface of the display panel 501 .

Meanwhile, although FIG. 4 shows a configuration in which the air layer 190 is provided between the light guide plate 100 and the display panel 501, the present embodiment is not limited thereto and may be configured as shown in FIG. 5.

5 is a view showing a display device according to another embodiment to which the backlight unit according to the first embodiment is applied. A description of the display device to be described later may include the same elements as those of the previously described embodiment. A description overlapping with the above-described embodiment may be omitted. Also, the same components have the same reference numerals.

Referring to FIG. 5 , in a display device 1100 according to another embodiment to which the backlight unit 500 according to the first embodiment is applied, the light guide plate 100 and the display panel 501 may contact each other. That is, compared to FIG. 4 , the display device 1100 according to FIG. 5 may have a structure in which an air layer is removed between the light guide plate 100 and the display panel 501 .

In the display device 1100 according to FIG. 5 , light emitted from the light source module 120 passes through the lens unit 130 and enters the light guide plate 100 . A portion of the light incident on the light guide plate 100 may be emitted in the direction of the display panel 501 immediately after being incident on the light guide plate 100 .

In addition, some of the light incident on the light guide plate 100 through the lens unit 130 has a refractive index lower than that of the light guide plate 100, so that the light guide plate 100 and the low refractive resin layer 140 ) can occur at the interface of In this way, the light that is totally reflected at the interface between the light guide plate 100 and the low refractive index resin layer 140 may travel inside the light guide plate 100 and be emitted toward the display panel 501 .

That is, the display device according to the above-described embodiments allows light to enter the light guide plate 100 without light loss through the lens unit 130 including the aspheric area, and partially reflects the light through the low refractive index resin layer 140. to be emitted in the direction of the display panel 501. This has an effect of reducing the loss of the light emitted from the light source module 120 and finally allowing the light to enter the display panel 501 .

In addition, since the display device according to the above-described embodiments uses glass as a light guide plate, light efficiency can be improved, and thus the thickness of the backlight unit can be reduced compared to display devices that do not use a glass light guide plate. .

Next, with reference to FIG. 6, the backlight unit according to the second embodiment is reviewed as follows. 6 is a diagram illustrating a backlight unit according to a second embodiment. A description of the backlight unit to be described later may include the same components as those of the previously described embodiment. A description overlapping with the above-described embodiment may be omitted. Also, the same components have the same reference numerals.

Referring to FIG. 6 , the backlight unit 600 according to the second embodiment includes a light guide plate 300, a light source module 120, a low refractive index resin layer 140, a reflective layer 150, and a cover member 160. .

At this time, the light guide plate 300 may be divided into a body part 310 and a lens part 320 . The lens unit 320 of the light guide plate 300 may be provided on one side of the body unit 310, and the body unit 310 and the lens unit 320 may be integrally formed.

The body 310 of the light guide plate 300 may have a polygonal column shape. For example, the body portion 310 may have a rectangular pillar shape. Also, one side of the lens unit 320 of the light guide plate 300 may be convex or concave. Preferably, one side of the lens unit 320 of the light guide plate 300 may be convex in the direction of the light source module 120 . That is, since one side of the light guide plate is formed of the lens unit 320 having a convex shape or a concave shape, the backlight unit 600 according to the present embodiment does not need to separately include the lens unit 320, so the configuration is simple. There is a cancellation effect.

Meanwhile, the shape of the lens unit 320 of the light guide plate 300 according to the present embodiment is not limited thereto. For example, the vertical portion V of the lens portion 320 of the light guide plate 300 according to the present embodiment is 0.15 to 0.3 greater than the height T of the body portion 310 based on the center of the lens portion 320. It is cut to the length of a ship, and the horizontal portion (H) of the lens unit 320 is cut to a length of 1 to 2.5 times the height (T) of the body portion 310 based on the center of the lens unit 320. can be In this way, the horizontal portion (H) and the vertical portion (V) of the lens unit 320 are formed in a shape cut at a predetermined ratio compared to the height (T) of the body portion 310, so that light emitted from the light source module 120 There is an effect of narrowing the vertical angle of the beamed light.

A lens unit 320 is provided on one side of the body 310 of the light guide plate 300, and a light source module 120 is disposed on one side of the lens unit 320. That is, the lens unit 320 may be disposed between the body 310 of the light guide plate 300 and the light source module 120 .

As described above, since the lens unit 320 is disposed between the body 310 of the light guide plate 300 and the light source module 120, the light emitted from the light source module 120 is condensed to form the body of the light guide plate 300. Light may be received into the unit 310 . Here, a convex or concave area of the lens unit 320 where the light guide plate 300 may face the light source module 120 . Through this, it is possible to narrow the vertical direction angle of the light emitted from the light source module 120 .

One side of the lens unit 320 of the light guide plate 300 may be convex or concave. At this time, when one side of the lens unit 320 is convex with respect to the light source module 120 as a standard, the corner of the lens unit 320 may have a rounded shape.

Subsequently, a review of the display device to which the backlight unit according to the second embodiment as described above is applied is as follows.

7 is a view showing a display device to which a backlight unit according to a second embodiment is applied. A description of the display device may include the same elements as those of the previously described embodiment. A description overlapping with the above-described embodiment may be omitted. Also, the same components have the same reference numerals.

Referring to FIG. 7 , a display device 1200 to which a backlight unit 600 according to the second embodiment is applied includes a backlight unit 600 and a display panel 501 disposed on the backlight unit 600 .

The backlight unit 600 according to the second embodiment includes a light guide plate 300 in which a lens unit 320 and a body unit 310 are integrally formed. At this time, one side of the lens unit 320 may have a convex shape or a concave shape, and the convex shape or concave shape may be disposed to face the light source module 120 . Through this, the vertical angle of the light emitted from the light source module 120 may be narrowed to be incident on the light guide plate 300 .

In addition, the low refractive index resin layer 140 is disposed on the rear surface of the light guide plate 300 and the air layer 190 is disposed on the upper surface of the light guide plate 300, so that the interface between the light guide plate 300 and the low refractive index resin layer 140 and the light guide plate The amount of light guided into the light guide plate 300 may be increased by inducing total reflection of light at the interface between the light guide plate 300 and the air layer 190 .

Meanwhile, as the vertical angle of light is narrowed, the light is incident at an angle greater than the critical angle of total reflection into the light guide plate 300, and total reflection of the light can be smoothly performed at the boundary between the light guide plate 300 and the low refractive index resin layer 140. Accordingly, the light may move to the entire area of the light guide plate 300 and be uniformly irradiated to the display panel 501 .

This configuration is reviewed with reference to FIG. 8 as follows. 8 is a graph illustrating a relationship between a low refractive index resin layer and a vertical beam angle of light incident on a light guide plate.

Referring to FIG. 8 , the horizontal axis represents the refractive index of the low refractive index resin layer, and the vertical axis represents the vertical angle of light. Meanwhile, in FIG. 8 , when the refractive index of the light guide plate is 1.52, when the refractive index of the low refractive resin layer is in the range of 1.3 to 1.5, the vertical angle of light may be in the range of 60 degrees to 90 degrees.

Meanwhile, in FIG. 8, when the refractive index of the low-refractive resin layer is less than 1.3, since there is no material having a refractive index of less than 1.3, the material for the low-refractive resin layer cannot be selected, so the refractive index range of less than 1.3 is designated as an unusable region, and the low-refractive resin When the refractive index of the layer exceeds 1.5, the light reaching the boundary between the light guide plate and the low refractive resin layer is not totally reflected, and the amount of light guided to the light guide plate is reduced.

In the case of the conventional backlight unit, the vertical angle of the light emitted from the light source module is made more than 100 degrees, so that the amount of light lost is large, whereas in the case of the backlight unit according to the present embodiment, the vertical direction of the light emitted from the light source module When the angle is in the range of 60 degrees to 90 degrees, there is an effect of increasing the amount of light guided to the light guide plate.

Next, with reference to FIG. 9 , a display device according to another embodiment to which the backlight unit according to the second embodiment is applied is reviewed as follows. 9 is a view showing a display device according to another embodiment to which the backlight unit according to the second embodiment is applied. A description of the display device to be described later may include the same elements as those of the previously described embodiment. A description overlapping with the above-described embodiment may be omitted. Also, the same components have the same reference numerals.

In the display device 1300 according to FIG. 9 , light emitted from the light source module 120 passes through the lens unit 320 of the light guide plate 300 and enters the body portion 310 of the light guide plate 300 . As described above, some of the light incident on the light guide plate 300 may be emitted in the direction of the display panel 501 immediately after entering the light guide plate 300 .

In addition, since the refractive index of the low refractive resin layer 140 is lower than the refractive index of the light guide plate 300, a part of the light incident on the body part 310 through the lens unit 320, the light guide plate 300 and the low refractive resin layer ( 140) may occur at the interface. In this way, the light that is totally reflected at the interface between the light guide plate 300 and the low refractive index resin layer 140 may travel inside the light guide plate 300 and be emitted toward the display panel 501 .

As described above, in the display device according to the present embodiments, the backlight unit includes a lens unit between the light source and the light guide plate, and includes a low refractive resin layer having a refractive index lower than that of the light guide plate on the rear surface of the light guide plate, so that light incident from the light source module to the light guide plate There is an effect of increasing the amount of light guided to the light guide plate by narrowing the vertical angle of light.

The features, structures, effects, etc. described in the foregoing embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified with respect to other embodiments by those skilled in the art in the field to which the embodiments belong. Therefore, contents related to these combinations and variations should be construed as being included in the scope of the present invention.

In addition, although the embodiments have been described above, these are merely examples and do not limit the present invention, and those of ordinary skill in the field to which the present invention belongs can exemplify the above to the extent that does not deviate from the essential characteristics of the present embodiment. It will be seen that various variations and applications that have not been made are possible. For example, each component specifically shown in the embodiments can be modified and implemented. And differences related to these variations and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

100: light guide plate
120: light source module
130: lens unit
140: low refractive resin layer
150: reflective layer

Claims (19)

light guide plate;
a lens unit integrally formed with a body of the light guide plate on at least one side surface of the light guide plate;
a light source module disposed on at least one side of the lens unit;
a low-refractive resin layer disposed on the rear surface of the light guide plate and having a refractive index lower than that of the light guide plate and having a refractive index of 1.3 to 1.5; and
A reflective layer disposed on the back surface of the low refractive index resin layer,
One side of the lens unit has a convex shape and has rounded corners,
The low refractive index resin layer is directly disposed on the light guide plate, and the reflective layer is directly disposed on the low refractive index resin layer.
delete According to claim 1,
The lens unit is a backlight unit having a bar shape.
delete According to claim 1,
The backlight unit of claim 1 , wherein the lens part is made of the same material as the body part of the light guide plate.
delete According to claim 1,
The vertical part of the lens part has a shape cut to a length 0.15 to 0.3 times the height of the body part,
The backlight unit of claim 1 , wherein the horizontal portion of the lens portion has a shape cut to a length 1 to 2.5 times greater than the height of the body portion.
According to claim 1,
A backlight unit comprising a plurality of protrusions disposed between one surface of the light guide plate and the low refractive index resin layer.
According to claim 1,
The backlight unit of claim 1 , wherein a vertical and downward angle of the lens unit is 60 degrees to 90 degrees.
light guide plate;
a lens unit integrally formed with a body of the light guide plate on at least one side surface of the light guide plate;
a light source module disposed on at least one side of the lens unit;
a low-refractive resin layer disposed on the rear surface of the light guide plate and having a refractive index lower than that of the light guide plate and having a refractive index of 1.3 to 1.5;
a reflective layer disposed on a rear surface of the low refractive index resin layer;
A display panel disposed on the upper surface of the light guide plate;
One side of the lens unit has a convex shape and has rounded corners,
The low refractive index resin layer is directly disposed on the light guide plate, and the reflective layer is directly disposed on the low refractive index resin layer.
delete According to claim 10,
The lens unit is a display device having a bar shape.
delete According to claim 10,
The lens part is made of the same material as the body part of the light guide plate.
delete According to claim 10,
The vertical part of the lens part has a shape cut with a length of 0.15 to 0.3 times the height of the body part based on the center of the lens part,
The display device of claim 1 , wherein the horizontal portion of the lens unit is cut to a length of 1 to 2.5 times the height of the body unit based on the center of the lens unit.
According to claim 10,
A display device comprising a plurality of protrusions disposed between one surface of the light guide plate and the low refractive index resin layer.
According to claim 10,
and an air layer disposed between the light guide plate and the display panel.
According to claim 10,
The display device wherein the vertical angle of the lens unit is 60 degrees to 90 degrees.

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