KR20160049588A - Backlight Unit - Google Patents

Backlight Unit Download PDF

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Publication number
KR20160049588A
KR20160049588A KR1020140146132A KR20140146132A KR20160049588A KR 20160049588 A KR20160049588 A KR 20160049588A KR 1020140146132 A KR1020140146132 A KR 1020140146132A KR 20140146132 A KR20140146132 A KR 20140146132A KR 20160049588 A KR20160049588 A KR 20160049588A
Authority
KR
South Korea
Prior art keywords
light
guide plate
light guide
light source
cover bottom
Prior art date
Application number
KR1020140146132A
Other languages
Korean (ko)
Inventor
오주석
Original Assignee
희성전자 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 희성전자 주식회사 filed Critical 희성전자 주식회사
Priority to KR1020140146132A priority Critical patent/KR20160049588A/en
Publication of KR20160049588A publication Critical patent/KR20160049588A/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133608—Direct backlight including particular frames or supporting means

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight device of a side dimming type in which a light source is disposed on a side surface of a light guide plate and a light output surface of the light source is arranged in a longitudinal direction to improve appearance characteristics, A cover bottom which folds upward to form a storage space therein; A light guide plate that is seated in a receiving space of the cover bottom; An optical sheet laminated on the light guide plate; A guide panel having a horizontal portion and a vertical portion extending downwardly from an end portion of the horizontal portion, the guide portion having a groove portion on one side edge of the horizontal portion on which the light source is seated, And an LED array in which a plurality of LED packages are mounted on the substrate at regular intervals and the emitting surface of the LED package is coupled to the groove portion of the guide panel so as to face the lower light guide plate.

Description

BACKLIGHT UNIT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight device, and more particularly, to a backlight device of a side dimming type in which a light source is disposed on a side surface of a light guide plate, and a backlight device for improving appearance by arranging a light-

Unlike other display devices, a liquid crystal display (LCD) device, which is a flat display device, can not emit light by itself, and thus an external light source is necessarily required to realize a high quality image do. Therefore, the LCD further includes a backlight device as a light source in addition to the liquid crystal panel, and the backlight device realizes an image by uniformly supplying a high-luminance light source to the liquid crystal panel.

As described above, the backlight device refers to an illumination device for realizing an image of a display device such as an LCD, and is divided into a direct lighting type or an edge lighting type backlight device according to the position of a light source. The direct-type backlight device illuminates light directly on a liquid crystal panel through a diffusion plate and an optical sheet in a lower light source. In a side-type backlight device, a light source is disposed on a side of a light guide plate, To illuminate. As a light source of a backlight device, a light emitting diode (hereinafter referred to as 'LED') having advantages such as small size, low power consumption and high reliability is mainly used.

FIG. 1 is a schematic cross-sectional view illustrating a structure of a light source unit of a conventional side-type backlight unit, and FIG. 2 is a plan view showing light output characteristics of the backlight unit of FIG.

First, as shown in Fig. 1, the backlight device includes a cover bottom 11 in the form of a rectangular plate, a reflective sheet 12 seated inside the cover bottom, a light guide plate 13 seated on the reflective sheet, An LED array 14, an optical sheet 15 stacked on top of the light guide plate, and a guide panel 16 fastened along the edge of the cover bottom. Here, the LED array 14 is disposed on one side of the storage space of the rectangular bottom cover 11, and the light of the plurality of point light sources is provided to the inside of the light guide plate through the side light incident surface of the light guide plate 13, Respectively.

The LED array 14 includes a plurality of LED packages 14b mounted on a substrate 14a on which a predetermined circuit is printed at regular intervals and a light emitting surface of the LED package 14b is disposed on the light- So that the light of the point light source emitted from the LED package 14b is incident directly into the light guide plate 13. [ As shown in FIG. 2, the optical characteristic of the backlight device emitted from the light-incoming portion by the point light source is shown as a bright region A of high luminance at the position where the LED package 14b is disposed, (I.e., between the LED packages) where the light-shielding portions (not shown) are not disposed.

Such a difference between the list and the dark part is observed as a hot spot from the outside, which is a factor that hinders the appearance of the backlight device. The hot spot problem is becoming more serious because of the recent development of the LED package 14b exhibiting high luminance and the increase in the spacing p between LED packages due to the use of a small number of LED packages 14b.

Since the hot spot appears only from the light incident surface of the light guide plate 13 to a predetermined width w, the horizontal width w of the guide panel 16 can be increased and blocked. However, in this case, the entire bezel width of the backlight device is widened, causing a problem that the image display area is relatively narrowed. Also, the hot spot can prevent the occurrence of the occurrence by narrowing the interval p between the LED packages 14b mounted on the substrate 14a, but this increases the number of the LED packages and eventually increases the manufacturing cost of the backlight device do.

In order to solve such a problem, in the prior arts disclosed in Korean Patent Laid-Open Publication No. 10-2011-0121247, a light source groove in which a light source is disposed is formed on the light incidence surface of a light guide plate, a reflection surface is formed on the right and left sides of the light source groove, A side-view backlight device having a structure in which an LED package emitting light to the side is disposed is disclosed. However, the backlight device of the prior art has a complicated structure of the light incidence surface area of the light guide plate, which makes it difficult to process the light guide plate, and the manufacturing cost of the backlight device is increased due to the use of the double-sided LED package.

Korean Patent Laid-Open No. 10-2011-0121247 (filed on July 11, 2011)

SUMMARY OF THE INVENTION The present invention has been proposed in order to solve the above problems, and it is an object of the present invention to provide a side-type backlight device in which light is incident on a side of a light guide plate, And it is an object of the present invention to provide a side-type backlight device capable of improving the appearance in the light-emitting region.

According to an aspect of the present invention, there is provided a backlight device including: a cover bottom, the bottom edge of which is folded upward to form a storage space therein; A light guide plate that is seated in a receiving space of the cover bottom; An optical sheet laminated on the light guide plate; A guide panel having a horizontal portion and a vertical portion extending downwardly from an end portion of the horizontal portion, the guide portion having a groove portion on one side edge of the horizontal portion on which the light source is seated, And an LED array in which a plurality of LED packages are mounted on the substrate at regular intervals and the emitting surface of the LED package is coupled to the groove portion of the guide panel so as to face the lower light guide plate.

Here, the light guide plate may include a reflective layer formed on a side surface and a lower surface of the light-incident portion where the LED array is disposed.

The light guide plate may have a slope or a curved surface on which the reflection layer is formed.

According to the present invention having the above-described structure, the light from the light source is incident in the lower longitudinal direction from the upper side of the end portion of the light guide plate, and then proceeds in the lateral direction, so that the list portion and the dark portion region are eliminated in the light incident portion generated by the plurality of point light sources The appearance of the backlight device is improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an assembled cross-sectional view illustrating a structure of a light source unit of a conventional side-
FIG. 2 is a plan view showing light output characteristics for the backlight device of FIG. 1,
FIG. 3 is an assembled cross-sectional view illustrating a light source structure of a side-view backlight device according to an embodiment of the present invention,
4 is an exploded cross-sectional view illustrating an assembling process of the backlight device of FIG. 3,
FIG. 5 and FIG. 6 are assembly sectional views showing various modifications of the light source structure of the side-type backlight device according to the embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is an assembled cross-sectional view illustrating a structure of a light source of a side-type backlight device according to an embodiment of the present invention, and FIG. 4 is an exploded cross-sectional view illustrating an assembling process of the backlight device of FIG.

3, the backlight device of the present invention includes a cover-bottom 100 having a storage space therein, a reflective plate 200 seated inside the cover bottom, a light guide plate (not shown) 300, an LED array 400 disposed on one side of the light guide plate at one side of the light guide plate, an optical sheet 500 stacked on the light guide plate, and a guide panel 600 fastened along the edge of the cover bottom .

Here, the cover bottom 100 is a hexahedral housing having an open upper side. The cover bottom 100 is divided into a bottom plate 110 having a rectangular plate shape and a vertical portion 120 having the edge of the bottom portion 110 extending upward, Form a storage space in which the respective components are housed. The bottom part 110 constitutes a seating surface on which the respective components are seated and the vertical part 120 functions as a fastening means for protecting the housed components from the external environment and fastening to the guide panel 600 do.

The reflection plate 200 improves the brightness of the backlight unit by causing the light leaked to the lower side of the light guide plate 300 to enter the inside of the light guide plate 300 again. The reflector 200 is composed of a film or sheet having excellent light reflection characteristics and is mounted on the bottom portion 110 of the cover bottom 100 in a rectangular shape.

The light guide plate 300 is a light switching device that receives light from a plurality of point light sources from the LED array 400 and converts the light into planar light by total internal reflection and emits the light to the upper side. The light guide plate 300 is made of a transparent acrylic resin having a predetermined refractive index. For example, a resin such as PMMA (Polymethylmethacrylate), PS (Poly styrene), MS (Meta styrene) or PC (Polycarbonate) . The light guide plate 300 has a rectangular shape corresponding to the bottom portion 110 of the cover bottom 100 and is seated inside the cover bottom 100 from above the reflection plate 200.

The LED array 400 is a light source of a backlight device that provides light of a plurality of point light sources to the inside of the light guide plate. A plurality of LED packages 420 are mounted on the substrate 410 on which a predetermined circuit is printed, . In particular, the LED array 400 of the present invention is coupled to the guide panel 600 and allows light from the point light source to enter through the upper surface of the light guide plate 300. That is, as shown in the figure, the LED array 400 is fastened to the guide panel 600 such that the light emitting surface of the LED package 420 faces downward. According to the fastening structure of the LED array 400, the upper surface of one side of the light guide plate 300 functions as the light incidence surface 300a, the lower surface and the side surface function as the reflection surface 300b, The remaining area of the upper surface except for the light-incident surface 300b functions as the light-exiting surface 300c.

The optical sheet 500 is a light control element for improving optical characteristics such as a directivity angle, a luminance and a uniformity with respect to light of a planar light source emitted from the light guide plate 300. The optical sheet 500 may include a prism sheet and a diffusion sheet, and may be composed of a plurality of sheets having various functions.

The guide panel 600 has a rectangular flange shape with the center open, and the light from the surface light source of the light guide plate 300 is emitted to the central window region. The guide panel 600 includes a horizontal portion 610 and a vertical portion 620 extending downward from an outer end of the horizontal portion. The horizontal portion 610 constitutes an edge bezel region of the backlight device, and the vertical portion 620 Is formed with fastening means to be fastened to the cover bottom 100. In the guide panel 600, a groove 630 for arranging a light source is formed in a horizontal portion 610 of one side, and the LED array 400 in the groove 630 is formed of a thermal pad or an electrothermal tape thermal tape, or the like.

The guide panel 600 includes a reflection plate 200, a light guide plate 300, and an optical sheet 500, which are coupled to the cover bottom 100 while covering the edges of the light guide plate 300 and the optical sheet 500, (500). The cover bottom 100 and the guide panel 600 are assembled to each other by fastening the vertical portions 120 and 620. Various vertical fastening means (not shown) are formed on the vertical portions 120 and 620, respectively. In this case, since the LED array 400 is fastened to the horizontal portion 610 of the guide panel 600, the interference of the LED array 400 with the fastening means of the cover bottom 100 and the guide panel 600 can be prevented The fastening means in each of the vertical portions 120 and 620 can be easily processed.

The light emitted from the LED array 400 is incident into the light guide plate 300 through the upper surface of the light guide plate 300 and the light incident into the light guide plate 300 is reflected And then proceeds to the central region inside the light guide plate 300. At this time, as shown in the drawing, the light guide plate 300 has the reflective layer 310 formed at the edges of the side surface and the bottom surface. The reflective layer 310 changes the direction so that the light incident on the LED array 400 downwardly advances to the central region inside the light guide plate 300 without leakage. The reflective layer 310 for this purpose is formed on a part of the bottom surface of the light guide plate 300 together with the side surface thereof. The reflective layer 310 may be formed by applying an ink having excellent light reflectance to the surface of the light guide plate, or attaching a reflective tape.

According to the present invention having the above-described structure, there is no problem of luminance deviation in a light-incident portion generated in a side-type backlight device using an LED as a light source due to the arrangement structure of the LED array. This is because the light incident to the inside of the light guide plate in the longitudinal direction at the end portion of the light guide plate is mixed with dispersion and scattering in the process of changing from the longitudinal direction to the lateral direction.

4, the cover bottom 100, the reflection plate 200, the light guide plate 300, and the cover bottom assembly to which the optical sheet 500 is coupled are assembled, After assembling the guide panel assembly to be fastened to the guide panel 600 and the LED array 400 separately, assembly is performed by fastening the guide panel assembly to the cover bottom assembly.

Specifically, first, the reflection plate 200 and the light guide plate 300 are sequentially seated in the interior accommodating space of the cover bottom 100. At this time, the light entrance side end of the light guide plate 300 is assembled so as to be close to the vertical portion 120 of the cover bottom 100. Further, an optical sheet 500 including a prism sheet and a diffusion sheet is stacked on the light guide plate 300. In addition to the assembly of the cover bottom assembly, the LED array 400 is attached to the horizontal portion of the guide panel 600 in the light-incoming area. At this time, the LED array 400 is attached to the lower surface of the guide panel horizontal portion 610 by a separate adhesive means 430. Finally, the guide panel 600 and the cover bottom 100 are fastened together by fastening means formed on the respective vertical portions 120 and 620, thereby completing assembly.

5 and 6 are sectional views illustrating various modifications of the light source structure of the side-type backlight device according to the embodiment of the present invention.

As shown in these figures, in the backlight device according to another embodiment of the present invention, the reflective surface 300b of the side surface and the bottom surface of the light guide plate of the light-incident portion region forms an inclined surface, A curved surface can be formed as shown in FIG. 5 and 6, when the reflective surface 300b of the end portion forms an inclined surface or a curved surface toward the central region of the light guide plate 300, the light incident in the longitudinal direction from the upper side is reflected by the reflective surface of the inclined surface or the curved surface, It can easily be changed.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

100: Cover bottom
110: bottom part 120: vertical part
200: reflector
300: light guide plate 310: reflective layer
400: LED array 410: substrate
420: LED package 430: adhesive means
500: Optical sheet
600: guide panel 610: horizontal part
620: vertical part 630:

Claims (3)

A cover bottom which forms a storage space therein while the bottom edge of the plate is bent upward;
A light guide plate that is seated in a receiving space of the cover bottom;
An optical sheet laminated on the light guide plate;
A guide panel having a horizontal part and a vertical part extending downward from an end of the horizontal part, the guide part being provided at one side edge of the horizontal part with a groove part on which the light source is seated, And
And a plurality of LED packages mounted on the substrate at regular intervals, and the LED array being coupled to the groove portion of the guide panel so that the light emitting surface of the LED package faces the light guide plate on the lower side. The light guide plate according to claim 1,
And a reflective layer formed on the side and bottom surfaces of the light-incident portion on which the LED array is disposed. The light guide plate according to claim 2,
Wherein the surface on which the reflective layer is formed has an inclined surface or a curved surface.
KR1020140146132A 2014-10-27 2014-10-27 Backlight Unit KR20160049588A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020140146132A KR20160049588A (en) 2014-10-27 2014-10-27 Backlight Unit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020140146132A KR20160049588A (en) 2014-10-27 2014-10-27 Backlight Unit

Publications (1)

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KR20160049588A true KR20160049588A (en) 2016-05-10

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Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020140146132A KR20160049588A (en) 2014-10-27 2014-10-27 Backlight Unit

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20180138233A (en) 2017-06-19 2018-12-31 희성전자 주식회사 Backlight unit

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20180138233A (en) 2017-06-19 2018-12-31 희성전자 주식회사 Backlight unit

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