KR101808082B1 - Led flat lighting - Google Patents

Abstract

Disclosed is an LED flat panel lighting device having an anti-glare structure. The LED flat panel lighting device having the anti-glare structure comprises: a light guide panel in which an LED module emits light with a side edge type; a reflective member which is provided in a back side of the light guide panel, and reflects the light of the light guide panel; a diffusing plate which is provided in a front side of the light guide panel, and transmits the light of the light guide panel; and a frame which prevents flow of the light guide panel, the reflective member, and the diffusing plate. An anti-glare unit, which protrudes toward the light guide panel provided between the LED module and the diffusing plate, is formed in the frame. The present invention prevents an anti-glare phenomenon without painting a black color on an end surface of the diffusing plate or attaching a shading sheet. The present invention provides uniformity of work by applying the same number of elastic members regardless of size of a lighting device. The present invention prevents excessive heat conduction to an LED by decreasing a touch pressure increasing rate between the LED and the light guide panel when thermal expansion of the light guide panel is performed.

Description

FIELD OF THE INVENTION [0001] The present invention relates to an LED flat panel illumination device having a light-

[0001] The present invention relates to an LED flat panel lighting apparatus having an anti-glare structure, and more particularly, to an LED flat panel lighting apparatus having an anti-glare structure for preventing light shining without coating a black color on the end face of a diffuser plate, And a lighting device.

Due to its excellent visibility and low driving voltage, LEDs are used extensively in point light sources and BLU (backlight unit) parts as well as pointing and signal light sources.

In this connection, Korean Patent Registration No. 1078850 discloses a lighting apparatus using a light guide plate. Japanese Patent Application Laid-Open No. 1078850 discloses a light emitting device having a polygonal annular frame, an LED module installed along the periphery of the frame, a light guide plate on which patterns and images are printed on the upper and lower surfaces, a reflective sheet provided on the upper portion of the light guide plate, And a cover for sealing the upper surface of the frame.

However, JP-A-1078850 has a problem in that a light splashing occurs in the inner part of the horizontal member (see Fig. 12). Light shading is a common problem with side edge type LED lighting fixtures because LED light intensively flows into the edge of the diffusion plate adjacent to the LED.

Conventionally, a silver or black shading sheet is coated on the end face of the diffuser plate to prevent blackening or blocking light. However, since the work of applying the black paint or attaching the light shielding sheet is carried out with air and material cost, improvement has been demanded.

On the other hand, Korean Patent Registration No. 1191748 discloses a backlight device having a structure capable of elastically buffering thermal expansion of a large light guide plate. Patent Document 1191748 discloses a light guide plate, a light source means for providing light to the light guide plate, and an edge portion surrounding the light guide plate so that the light source of the light source means is brought into close contact with at least one side surface of the light guide plate, And a frame for holding the light guide plate so that the light guide plate can move in the horizontal direction.

The frame includes a light source frame which is provided so as to support the light source so as to be in tight contact with at least one side face of the light guide plate and to move incidentally in the horizontal expansion and contraction movement of the light guide plate, So that the light source is always kept in close contact with at least one side surface of the light guide plate regardless of whether the light source frame is pushed toward the light guide plate to change the size in the horizontal direction due to thermal expansion or thermal shrinkage of the light guide plate And a guide member for guiding the horizontal movement of the light source frame forced to move in association with the expansion and contraction in the horizontal direction of the light guide plate.

The pressure formed on the contact surface between the LED and the light guide plate (hereinafter referred to as "contact pressure") should be maintained at an appropriate level. The contact area between the LED and the light guide plate and the elastic force of the leaf spring are the biggest factors determining the contact pressure.

If the contact pressure exceeds a proper level, there is a problem that heat energy of the light guide plate is excessively introduced into the LED. If the heat energy of the light guide plate is excessively introduced into the LED, the lifetime and efficiency of the LED module are reduced.

If the contact pressure is lower than the appropriate level, there is a possibility that the contact surface between the LED and the light guide plate may not be formed when the light guide plate is shrunk. That is, when the use period of the backlight device has elapsed, dust and moisture flow into the frame body. If the frictional force between the light source frame and the frame body exceeds the elastic force of the leaf spring due to the inflow dust and moisture, .

However, since the elastic force of the leaf spring for pushing the light source frame toward the light guide plate is generated only by the single bending part, the backlight device of the large-size area, that is, the number of LEDs mounted on the LED module is large, When the contact area between the light guide plate and the light guide plate is large, it is troublesome to install a plurality of leaf springs in order to satisfy an appropriate contact pressure.

In addition, in JP-A-1191748, as the magnitude of the elastic force of the leaf spring depends on the spring constant, there is a problem that the magnitude of the elastic force rapidly increases as the thermal expansion of the light guide plate progresses. If the contact pressure exceeds an appropriate level due to an increase in the elastic force of the leaf spring, heat energy of the light guide plate may be excessively introduced into the LED.

Korean Registered Patent No. 1078850 (Registered on October 26, 2011) Korean Registered Patent No. 1191748 (Registered on October 10, 2012)

It is an object of the present invention to provide a light source device and a light source device that can prevent light shining without applying black or shading sheets to the end face of a diffuser plate and uniformly work by applying the same number of elastic members regardless of the size of the lighting device, The LED flat panel illuminating device is provided with a light-preventing structure for reducing an increase rate of contact pressure between an LED and a light guide plate during thermal expansion of the LED, thereby suppressing excessive heat conduction to the LED.

According to an aspect of the present invention, there is provided an LED module including a light guide plate for illuminating light in a side edge type; A reflective member provided behind the light guide plate and reflecting the light entering the light guide plate; A diffusion plate provided in front of the light guide plate and transmitting light entering the light guide plate; And a frame for preventing the flow of the light guide plate, the reflection member, and the diffusion plate, wherein the frame is provided with a light blocking portion protruding toward the light guide plate between the LED module and the diffusion plate. The LED flat panel illumination device according to claim 1,

The frame may have a rail portion on which the light blocking portion is mounted so as to be slidable toward the diffusion plate, and the light blocking portion may be pressed toward the diffusion plate by the elastic force of the elastic member.

And a stretching member interposed between the LED module and the frame and stretching and shrinking at the time of thermal expansion of the light guide plate.

A heat dissipator is interposed between the LED module and the elastic member, the elastic member includes a first contact portion coupled to the frame or the heat dissipator and forming a first contact surface with the frame; And a second contact portion connected to the first contact portion and forming a second contact surface with the heat dissipating member. The first contact surface and the second contact surface may be moved when the light guide plate is thermally expanded.

Wherein at least any one of the first contact surface and the second contact surface is inclined with respect to at least one of the frame and the heat dissipating member so as to be inclined with respect to the elongating and contracting direction of the elongate and contractible member so as to reduce the elongation and contraction of the elastic member upon thermal expansion of the light guide plate May be formed.

An inflow path may be formed at the distal end of the ramp so that the direction of the ramp is reversed with respect to the extending and retracting direction of the elastic member in order to form a limit of expansion and contraction of the elastic member upon thermal expansion of the light guide plate.

And a third contact portion connected to the second contact portion and forming a third contact surface with the frame.

According to the present invention, by providing the light blocking portion protruding toward the light guide plate between the LED module and the diffusion plate, it is possible to provide a light blocking prevention structure for preventing the light leakage phenomenon without coating the end face of the diffusion plate with black or attaching a light- It becomes possible to provide an LED flat panel illumination device.

In addition, by forming an operating structure that generates an elastic force by the movement of a plurality of contact surfaces during thermal expansion of the light guide plate, the same number of elastic members are applied regardless of the size of the lighting apparatus, It becomes possible to provide a lighting device.

In addition, since a ramp is formed in which at least one of the first contact surface and the second contact surface moves obliquely with respect to the elongating and contracting direction of the stretchable member, at least any one of the frame and the heat sink, thereby lowering the rate of increase in contact pressure between the LED and the light guide plate It is possible to provide an LED flat panel illumination device having a light blocking structure that is designed to suppress excessive heat conduction to the LED.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a major part of an LED flat panel illumination device having a light blocking structure according to an embodiment of the present invention; FIG.
FIG. 2 and FIG. 3 are cross-sectional views of a main part of an LED flat panel illumination device having an anti-glare structure according to another embodiment of the present invention. FIG.
FIGS. 4 and 5 are cross-sectional views of major parts of an LED flat panel illumination device having an anti-glare structure according to another embodiment of the present invention. FIG.
6 and 7 are cross-sectional views of major parts of an LED flat panel illumination device having a light blocking structure according to another embodiment of the present invention.
Fig. 8 is a force-deformation diagram of a stretchable member in an LED flat panel illumination apparatus having the anti-glare structure of Figs. 4 to 7. Fig.
9 and 10 are cross-sectional views of major parts of an LED flat panel illumination device having an anti-glare structure according to another embodiment of the present invention.
Fig. 11 is a view showing suppression of light leakage phenomenon of the LED flat panel illumination device having the light blocking structure of Fig. 1; Fig.
FIG. 12 is a diagram showing the light-emitting phenomenon of a conventional LED flat panel illumination device. FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, the well-known functions or constructions are not described in order to simplify the gist of the present invention.

The LED flat panel illumination device of the present invention can prevent light shining phenomenon without applying black or shading sheet to the end face of the diffusion plate and apply the same number of elastic members irrespective of the size of the lighting device And the increase in the contact pressure between the LED and the light guide plate during thermal expansion of the light guide plate is lowered to suppress excessive heat conduction to the LED.

FIG. 1 is a cross-sectional view of a major portion of an LED flat panel illumination apparatus having a light blocking structure according to an embodiment of the present invention, and FIGS. 2 and 3 are cross-sectional views showing major parts of an LED flat panel illumination apparatus having a light blocking structure according to another embodiment of the present invention. 6 and 7 are cross-sectional views illustrating a light-blocking structure according to another embodiment of the present invention, FIGS. 4 and 5 are sectional views of major parts of an LED flat panel illumination device having a light- FIG. 8 is a force-deformation diagram of a stretchable member in an LED flat panel illumination apparatus having the anti-glare structure of FIGS. 4 to 7, FIGS. 9 and 10 show another embodiment of the present invention Fig. 11 is a view showing the suppression of light leakage phenomenon of the LED flat panel illumination device having the anti-glare structure of Fig. 1, Fig. 12 is a cross-sectional view of the conventional LED flat panel illumination deviceThe figure representing a splash phenomenon.

As shown in FIG. 1, the LED flat panel illumination device 10 having a light-preventing structure according to an embodiment of the present invention is configured to have a structure in which a light- And includes a light guide plate 100, a reflective member 200, a diffuser plate 300, a frame 400, and an LED module 500.

In the following description of the light guide plate 100, the reflective member 200, and the diffuser plate 300, 'front' and 'front' are the center directions in which light is emitted to the outside, 10, and "rear", "rear", and "front" are to be understood to mean the opposite direction of "front", that is, the upper side of FIGS. 1 to 4 and 6 to 10 do. And 'front' means front side, and 'rear side' means rear side.

The light guide plate 100 is configured to uniformly disperse the light of the LED 510 over a predetermined area, and may be formed in the form of a rectangular (or polygonal) flat plate. The light guide plate 100 may be made of PMMA (Polymethylmethacrylate). Although not shown, an optical pattern may be formed on the back surface of the light guide plate 100 to help uniform dispersion of light.

The reflective member 200 is provided on the back side of the light guide plate 100 to reflect light entering the light guide plate 100 forward. The reflective member 200 may be a white film made of PET (polyethylene terephthalate).

Of course, the reflective member 200 may be made of aluminum or an alloy. Since the reflective member 200 can be in contact with the light source, it is preferable that the reflective member 200 is made of a material having a high thermal conductivity.

As shown in FIGS. 1 and 2, a protective member P may be provided on the rear side of the reflective member 200. The protective member P is provided between the reflective member 200 and the cover 420 to prevent external force or heat applied to the cover 420 from being transmitted directly to the reflective member 200.

The diffusion plate 300 diffuses light entering the light guide plate 100 along the surface and transmits the light. The diffusion plate 300 is disposed in front of the light guide plate 100. The diffuser plate 300 may be made of high purity acrylic resin. The light emitted from the light source passes through the diffusion plate 300 and is discharged to the outside, so that the color and brightness are uniformly observed as a whole.

The frame 400 is a structure for preventing the flow of the light guide plate 100, the reflection member 200 and the diffusion plate 300, and forms the skeleton of the flat panel illumination device 10. The frame 400 may be formed in the form of a rectangular (or polygonal) frame. As shown in FIG. 1, the frame 400 may include a body 410 and a cover 420.

The lower portion of the body 410 (hereinafter referred to as 'front frame 411') forms a frame covering the edge of the diffusion plate 300. The diffusion plate 300 is seated on an end portion of the front frame 411 (hereinafter referred to as a 'support end portion 413').

A heat radiating frame 412 through which the heat of the LED module 500 is conducted is formed on the rear side of the front frame 411. The cover 420 is coupled to the rear surface of the body 410 to prevent vertical movement of the light guide plate 100, the reflective member 200, and the diffusion plate 300.

1 and 2, the LED module 500 is configured to illuminate the light guide plate 100 in a side edge type, and is interposed between the light guide plate 100 and the heat radiation frame 412 .

In the following description of the LED module 500, the heat dissipating frame 412 and the heat dissipating body 700 to be described later, the forward direction and the front direction are the center directions in which light is emitted from the LED 510, 6 to 10, and the left side of FIG. 1 to FIG. 4 and FIG. 6 to FIG. 10, the left side of FIG. Should be understood as meaning. And 'front' means front side, and 'rear side' means rear side.

Japanese Patent Application Laid-Open No. 1078850 has a problem in that a light splashing phenomenon (see FIG. 12) occurs in the inner portion of the horizontal member. Light shading is a common problem with side edge type LED lighting fixtures because LED light intensively flows into the edge of the diffusion plate adjacent to the LED.

Conventionally, a silver or black shading sheet is coated on the end face of the diffuser plate to prevent blackening or blocking light. However, since the work of applying the black paint or attaching the light shielding sheet is carried out with air and material cost, improvement has been demanded.

As shown in FIG. 1, in the LED flat panel lighting apparatus 10 having a light blocking structure according to an embodiment of the present invention, a light blocking prevention portion 414 is formed in the front frame 400.

The light shielding portion 414 protrudes toward the light guide plate 100 between the LED module and the diffusion plate 300. Therefore, even if the light shielding sheet is not attached to the end face of the diffusion plate 300 or a silver or black light shielding sheet capable of shielding light can be attached to the diffusion plate 300 The light of the LED 510 is prevented from intensively flowing into the edge portion of the LED 510. Fig. 11 shows that the light fading phenomenon inside the front frame 411 is prevented by the formation of the light blocking portion 414. Fig.

2 and 3, in the LED flat panel illumination apparatus 20 having the light blocking structure according to another embodiment of the present invention, the light blocking prevention portion 414 is formed on the diffusion plate 300, And the light emission preventing portion 414 can be pressed toward the diffusion plate 300 by the elastic force of the elastic member S. [

The rail portion 416 is formed in a long groove shape and a mounting portion 415 is formed at the lower end portion of the light blocking portion 414 to slide while being inserted in the groove. The front frame 411 is provided with a mounting portion 417 on which one end of the elastic member S is mounted. The elastic member S is provided as a compression spring and is interposed between the mounting portion 417 and the light blocking portion 414 in a partially compressed state.

The light from the LED 510 flowing into the end surface of the diffusion plate 300 can be effectively blocked as the light blocking part 414 is closer to the end surface of the diffusion plate 300. Even when the size of the diffusion plate 300 is cut off due to the mistake of the operator or the malfunction of the diaphragm 300 in manufacturing the LED flat panel illumination device 20 having the light blocking structure, So that the light of the LED 510 flowing into the end surface of the diffusion plate 300 is completely cut off.

Even when unnecessary external force is applied to the surface of the diffusion plate 300 in the state where the LED flat panel illumination device 20 having the light blocking structure is used, the diffusion plate 300 is moved to the original position by the elastic force of the elastic member S. Return.

As shown in FIGS. 4 and 5, the LED flat panel lighting apparatus 30 having a light-blocking structure according to another embodiment of the present invention may include the same number of stretching members 600 irrespective of the size of the lighting apparatus And the excessive increase in the contact pressure between the LED 510 and the light guide plate 100 during thermal expansion of the light guide plate 100 is suppressed to suppress excessive heat conduction to the LED 510. The elasticity of the elastic member 600 and heat dissipation (700). 4 to 7, the illustration of the light blocking portion 414 is omitted.

4 and 5, the elastic member 600 has a structure in which the front surface of the LED 510 is brought into close contact with the side surface of the light guide plate 100 by self-elasticity, and the LED module 500 and the heat dissipation frame 412 In some compressed state.

The elastic member 600 is stretched and contracted between the LED module 500 and the frame 400 when the light guide plate 100 is thermally expanded. The elastic member 600 may be made of various materials such as metal, synthetic resin, and the like having self-elasticity.

A heat sink 700 is interposed between the LED module 500 and the elastic member 600. The heat dissipating unit 700 is configured to quickly discharge the heat of the LED module 500 and is coupled to the rear surface of the body 520 of the LED module 500.

The rear surface of the heat sink 700 (hereinafter referred to as "the first front view") and the front surface of the heat radiation frame 412 (hereinafter referred to as "second front view") form a plane parallel to each other. The heat sink 700 may be made of a material having good thermal conductivity such as aluminum.

As shown in Fig. 4, the elastic member 600 forms a plate or sheet in a multi-stepped shape. It is to be understood that the elastic member 600 forms a certain length in the normal direction of the cross section in the sectional view of FIG.

The stretchable member (600) forms at least one contact surface with each of the first preceding figure and the second preceding figure. 4 and 5 show that the elastic member 600 forms two contact surfaces respectively with the first and second entire views. Hereinafter, description will be made with reference to the states shown in FIGS. 4 and 5.

The elastic member 600 includes a first contact portion 610, a second contact portion 620, a third contact portion 630, and a fourth contact portion 640.

The first contact portion 610 is configured to form a first contact surface 611 with the heat dissipating frame 412. One end of the first contact portion 610 is coupled to the frame 400 or the heat dissipating body 700. 4 and 5, the upper end of the first contact portion 610 is shown coupled to the heat sink 700. [

This may optionally also couple the lower end of the first contact 610 to the heat dissipating frame 412. The first contact portion 610 forms a shape in which both portions of the first contact portion 610 are spaced apart from each other with respect to the first contact surface 611.

The upper end of the second contact portion 620 is connected to the lower end of the first contact portion 610. The second contact portion 620 is formed to form a second contact surface 621 with the heat dissipator 700. [ The second contact portion 620 forms a shape in which both portions of the second contact portion 620 are spaced apart from each other with respect to the second contact surface 621.

The third contact portion 630 is configured to form a third contact surface 631 with the heat dissipating frame 412. The upper end of the third contact portion 630 is connected to the lower end of the second contact portion 620. The third contact portion 630 forms a shape in which both portions of the third contact portion 630 are spaced apart from each other with respect to the first contact surface 631 as a reference.

The fourth contact portion 640 is configured to form a fourth contact surface 641 with the heat dissipator 700 and the upper end thereof is connected to the lower end portion of the third contact portion 630. The fourth contact portion 640 forms a shape in which both portions of the fourth contact portion 640 are widened toward the second front view with reference to the fourth contact surface 641. [

4 and 5, when the light guide plate 100 is thermally expanded, the first contact portion 610 is opened on the basis of the first contact surface 611, and the second contact portion 620 is opened on the second contact surface 611 The third contact portion 630 is opened on the basis of the third contact surface 631 and the fourth contact portion 640 is opened on the basis of the fourth contact surface 641, .

Accordingly, the elastic member 600 is contracted in the direction of thermal expansion of the light guide plate 100 during thermal expansion of the light guide plate 100, and elongated in the direction perpendicular thereto. Since the upper end of the first contact portion 610 is coupled to the heat dissipating member 700, the first contact surface 611, the second contact surface 621, the third contact surface 631, 4 contact surfaces 641 are moved downward on the first front view and the second front view, respectively.

In the case of a backlight device of a large area, that is, the number of LEDs mounted on the LED module is large and the number of the LEDs is small, When the contact area between the light guide plates is large, it is troublesome to install a plurality of plate springs in order to satisfy an appropriate level of contact pressure.

The LED flat panel illumination device 30 having the light blocking structure according to another embodiment of the present invention includes a plurality of contact portions for generating elastic force by the elastic members 600, And the remaining contact portions are respectively moved downward on the first and second previous drawings when thermally expanding the light guide plate 100 to form an elastic force, The number of contact portions can be increased and the elastic force can be increased. Therefore, since the same number of stretching members 600 can be applied to the small and large flat panel illumination devices 30, uniformity of assembling work can be achieved.

In addition, since the elastic force of the leaf spring for pushing the light source frame toward the light guide plate is generated only by the single bending portion, the heat of the LED module is inevitably formed in the structure of heat radiation to the frame body through the light source frame , Thus requiring a wide contact area of the light source frame and the frame body. The wide contact area of the light source frame and the frame body also functions to prevent the rotation of the light source frame.

However, if the frictional force between the light source frame and the frame body exceeds the elastic force of the leaf spring due to dust and moisture introduced into the frame body, It may not be pushed properly.

The LED flat panel lighting apparatus 30 having the light blocking prevention structure according to another embodiment of the present invention is configured such that the elastic member 600 contacts the heat radiating frame 412 and the heat discharging body 700 through a plurality of contact portions, The thermal energy of the LED module 500 is actively conducted to the heat radiating frame 412 through the heat sink 700 and the elastic member 600 even if the heat sink 700 and the frame 400 do not form a wide contact surface. There is an advantage that the heat is dissipated.

Heat energy of the LED module 500 is actively conducted and dissipated through the heat dissipating frame 412 through the heat dissipating unit 700 and the elastic member 600 so that the heat dissipating unit 700 is divided into a pair It is possible to prevent rotation of the LED module 500 by connecting to the heat dissipating frame 412 by the pin R of the LED module 500. [ The pin R may be coupled to the heat sink 700 in a state of being slidably inserted into a hole formed in the heat sink frame 412.

6 and 7, the LED flat panel illumination device 40 having a light-blocking structure according to another embodiment of the present invention may include a heat sink 400 and a heat sink 700, A ramp 401 may be formed in which at least one of the first contact surface 611 and the second contact surface 621 moves obliquely with respect to the elongating and contracting direction of the elastic member 600.

In Figures 6 and 7, a ramp 401 is shown formed in the second entire drawing. 6 and 7, the elastic member 600 includes a first contact portion 610, a second contact portion 620, a third contact portion 630, a fourth contact portion 640, a fifth contact portion 650, 6 contact portion 660. As shown in FIG.

The ramp 401 forms a tilted slope from the second preceding figure in a direction away from the first preceding figure. The first contact surface 611 (the third contact surface 631 and the fifth contact surface 651) for moving the ramp 401 during the thermal expansion of the light guide plate 100 is in contact with the second contact surface 621 (the fourth contact surface 641) ).

Hereinafter, for easy understanding of the present invention, the ramp 401 on which the first contact surface 611 moves is referred to as a ramp A, the ramp 401 on which the third contact surface 631 moves is referred to as ramp B, , And the inclined road 401 on which the fifth contact surface 651 moves is referred to as a ramp C.

6 and 7, the first contact portion 610, the second contact portion 620, the third contact portion 630, the fourth contact portion 640, the fifth contact portion 650, and the sixth contact portion 660, The second contact surface 621 is moved by a distance of 2X and the third contact surface 631 is moved by a distance of 2X assuming that the moving distance of the first contact surface 611 is X when the light guide plate 100 is thermally expanded. The fourth contact surface 641 moves a distance of 4X, and the fifth contact surface 651 moves a distance of 5X. Therefore, the ramp B is formed to have a length three times the length of the ramp A in the vertical direction, and the ramp C is formed to have a length five times the length of the ramp A in the vertical direction.

The pressure formed on the contact surface between the LED 510 and the light guide plate 100 (hereinafter referred to as 'contact pressure') should be maintained at an appropriate level. The contact area between the LED 510 and the light guide plate 100 and the elastic force of the elastic member 600 are the largest factors determining the contact pressure.

If the contact pressure exceeds a proper level, there is a problem that heat energy of the light guide plate 100 is excessively introduced into the LED 510. If the heat energy of the light guide plate 100 is excessively introduced into the LED 510, the lifetime and efficiency of the LED module 500 are reduced.

However, in Patent Document 1191748, as the magnitude of the elastic force of the leaf spring depends on the spring constant, there is a problem that the magnitude of the elastic force rapidly increases as the thermal expansion of the light guide plate progresses. If the contact pressure exceeds an appropriate level due to an increase in the elastic force of the leaf spring, heat energy of the light guide plate may be excessively introduced into the LED.

The stretching member 600 is assembled in a partially compressed state between the LED module 500 and the heat radiating frame 412. 8 shows the compressed length X1 and the elastic force F1 of the elastic member 600 during assembly. 8 shows the compressed length X2 and the elastic force F2 of the elastic member 600 at the time of thermal expansion of the light guide plate 100 when the inclined path 401 is formed.

8 shows the compressed length X3 and the elastic force F3 of the elastic member 600 at the time of thermal expansion of the light guide plate 100 when the inclined path 401 is not formed. That is, when the ramp 401 is formed, the elastic member 600 is compressed less by the length of 'X3-X2' and smaller by 'F3-F2' when thermal expansion of the light guide plate 100 is performed.

Accordingly, when the inclined path 401 is formed, the two-axis line diagram based on the distance X2 where the LED module is pushed and the elastic force F2 of the elastic member 600 can be displayed as shown in Fig. That is, at least one of the first contact surface 611 and the second contact surface 621 is inclined with respect to the elongating and contracting direction of the elastic member 600 in at least one of the heat generating frame 400 and the heat discharging body 700 401 are formed, the expansion and contraction of the elastic member 600 and the increase in the elastic force with respect to the distance at which the light guide plate 100 is thermally expanded are reduced. Accordingly, the increase rate of the contact pressure between the LED 510 and the light guide plate 100 is reduced, thereby suppressing excessive heat conduction from the light guide plate 100 to the LED 510.

6 and 7, at the distal end of the ramp 401, a curve 402 may be formed in which the direction of the ramp 401 reverses with respect to the direction of extension and contraction of the elastic member 600.

The inflow path 402 rapidly increases the area of the first contact surface 611, the third contact surface 631 and the fifth contact surface 651 by two or more times at the distal end of the ramp 401, Thereby forming a boundary point at which expansion and contraction of the elastic member 600 during thermal expansion of the elastic member 100 is suppressed.

The curved path 402 is normally formed at a limit point at which the light guide plate 100 can be thermally expanded (for example, at a stretching point of the elastic member 600 when the light guide plate 100 is heated to 40 캜 and thermally expanded). Therefore, when the light guide plate 100 is pushed toward the heat radiating frame 412 by an external force, the expansion and contraction of the elastic member 600 is suppressed in the state of FIG. 7 and as a result, the elastic member 600 is excessively expanded / contracted due to external force, (600) is prevented from being damaged.

9 and 10 show a state in which the elastic member 600 and the anti-glare unit 414 are installed at the same time. The contact surface between the LED 510 and the light guide plate 100 is maintained in a state in which the contact surface between the LED 510 and the light guide plate 100 is completely adhered by the elasticity of the elastic member 600 even if the light guide plate 100 and the diffusion plate 300 are thermally expanded and heat- The light blocking member 414 is completely in close contact with the end surface of the diffusion plate 300 by the elastic force of the elastic member S. [

Therefore, when the elastic member 600 and the light blocking member 414 are installed at the same time, the loss of light energy is minimized until the light of the LED 510 is emitted to the outside through the light guide plate 100 and the diffusion plate 300 There is an advantage to be maintained.

According to the present invention, by providing the light blocking portion protruding toward the light guide plate between the LED module and the diffusion plate, it is possible to provide a light blocking prevention structure for preventing the light leakage phenomenon without coating the end face of the diffusion plate with black or attaching a light- It becomes possible to provide an LED flat panel illumination device.

In addition, by forming an operating structure that generates an elastic force by the movement of a plurality of contact surfaces during thermal expansion of the light guide plate, the same number of elastic members are applied regardless of the size of the lighting apparatus, It becomes possible to provide a lighting device.

In addition, since a ramp is formed in which at least one of the first contact surface and the second contact surface moves obliquely with respect to the elongating and contracting direction of the stretchable member, at least any one of the frame and the heat sink, thereby lowering the rate of increase in contact pressure between the LED and the light guide plate It is possible to provide an LED flat panel illumination device having a light emitting prevention structure which is configured to suppress excessive heat conduction to the LED.

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 embodiments, but, on the contrary, It is obvious to those who have. Accordingly, it should be understood that such modifications or alterations should not be understood individually from the technical spirit and viewpoint of the present invention, and that modified embodiments fall within the scope of the claims of the present invention.

10, 20, 30, 40, 50:
100: light guide plate 600: elastic member
200: reflective member 610: first contact
P: protective member 611: first contact surface
300: diffusion plate 620: second contact portion
400: frame 621: second contact surface
401: ramp 630: third contact
402: an inflow path 631: a third contact surface
410: Body 640: Fourth contact
411: front frame 641: fourth contact surface
412: heat radiating frame 650: fifth contact portion
413: support end portion 651: fifth contact surface
414: Light blocking portion 660: Sixth contact portion
415: mounting portion 661: sixth contact surface
416: rail part 700: heat radiator
417: installation part R: pin
S: Elastic member
420: heat radiating frame
500: LED module
510: LED
520: Body

Claims (7)

A light guide plate for illuminating the LED module with a side edge type light;
A reflective member provided behind the light guide plate and reflecting the light entering the light guide plate;
A diffusion plate provided in front of the light guide plate and transmitting light entering the light guide plate;
And a frame for preventing the flow of the light guide plate, the reflection member, and the diffusion plate,
A light blocking prevention part protruding toward the light guide plate is formed between the LED module and the diffusion plate,
The frame is provided with a rail portion on which the anti-glare portion is mounted so as to be slidable toward the diffusion plate,
The light blocking portion is pressed toward the diffusion plate by the elastic force of the elastic member,
And a stretching member interposed between the LED module and the frame and stretching and shrinking at the time of thermal expansion of the light guide plate,
A heat dissipator is interposed between the LED module and the elastic member,
The elastic member
A first contact portion coupled to the frame or the heat sink and forming a first contact surface with the frame; And
And a second contact portion connected to the first contact portion and forming a second contact surface with the heat dissipator,
The first contact surface and the second contact surface move during thermal expansion of the light guide plate,
Wherein at least one of the first contact surface and the second contact surface is inclined with respect to at least one of the frame and the heat dissipating member so that the expansion and contraction of the elastic member upon thermal expansion of the light guide plate is reduced, Is formed,
Wherein a curved path is formed at the distal end of the ramp so that the direction of the ramp is reversed with respect to the direction of elongation and / or contraction of the elastic member, so as to form a limit of expansion / contraction of the elastic member upon thermal expansion of the light guide plate. LED flat panel illumination device. delete delete delete delete delete delete

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