GB2507404A

GB2507404A - Illumination apparatus

Info

Publication number: GB2507404A
Application number: GB1316480.1A
Authority: GB
Inventors: Chen-Wei Chu; Chun-Chien Liao
Original assignee: Young Lighting Technology Inc
Current assignee: Young Lighting Technology Inc
Priority date: 2012-10-26
Filing date: 2013-09-17
Publication date: 2014-04-30
Also published as: GB201316480D0; TWI499841B; TW201416773A

Abstract

An illumination apparatus includes a frame 110, a light guide plate 120, and a light emitting device 130. The frame has at least one light guiding channel 112 with an entrance 112a and an exit 112b. The light guide plate 120 is disposed in the frame 110, and has a light incident surface 122 and a light emergent surface 124. The light emitting device 130 is disposed between the frame 110 and the light guide plate 120. The light emitting device emits a light beam, a portion L1 of which enters into the light guide plate 120 through the light incident surface 122 and exits the light guide plate through the light emergent surface124. Another portion L2 of the light beam enters into the light guiding channel 112 through the entrance 112a and leaves the frame 110 through the exit 112b of the light guiding channel.

Description

ILLUMINATION APPARATUS

BACKGROUND OF THE INVENTION

$ 1. Field of the Invention

[0001] The invention relates to an illumination apparatus. and more particularly, to an edge type illumination apparatus.

2. Description of Related Art

[00021 Incandescent bulbs and fluorescent tubes are usually applied to conventional illumination equipments as the light sources. Along with the development of optoelectronics technology, light emitting diode (LED) has gradually replaced the conventional incandescent bulb and fluorescent tube and becomes a nex.tgeneration Ught source. LED offers many advantages such as ecofriendliness, low power consumption, and small volume therefore has been broadly applied to different illumination equipments.

[0003] Generally; an illumination equipment needs to illuminate a large area.

Since LED is considered a point hght source, when a LET) is applied to an iikiniination equipment, a light guide plate has to be adopted to achieve a large illumination area.

Taking the illumination of an indoor space as an example, the conventional illumination equipments are usually installed on the ceiling and eniit light downwards. in order to enhance the illumination unithrmit) the density of the illumination equipments has to be increased, However, the increase in the density of illumination equipments will heavily increase in the number of illumination equipments.

[00C4] Thereb to enhance the illumination uniformity without increasing the number of illumination equipments has to be resolved.

[0005] A display apparatus with embedded tight source is thscosea in Taiwan Patent No. M429 114.

SUMMARY OF THE INVENTION

[0006] Accordingly, the invention is directed to an illumination apparatus with at least one light guiding channel.

[0007] The invention provides an illumination apparatus including a frame, a light guide plate, and a light emitting device, The frame has at least one light guiding channel. the light guiding channel has an entrance and an exit. The light guide plate is disposed in the frame and has a light incident surface and a light emergent surface.

The light emitting device is disposed between the frame and the light guide plate. The light emitting device is suitable fhr emitting a light beams, .4 portion of the light beams enter into the light guide plate through the light incident surface and leaves the light guide plate through the light emergent surface. The other portion of the light beams enter into the light guiding channel through the entrance and leaves The frame through the exit of the light guiding channel, [0008] According to an embodiment of the invention, the frame has a light guide plate accommodating space and a light emitting device accommodating space. The light guide plate is disposed in the light guide plate accommodating space and the light emitting device is disposed in the light emitting device accommodating space. One end of the light guiding channel is connected with the light guide plate accommodating space and the light emitting device accommodating space.

[0009] According to an embodiment of the invention, the light guiding channel has a sidewall between the entrance of the light guiding channel and the exit of the light guiding channel, and the sidewall is a reflecting surface.

[0010] According to an embodinient of the invention, the reflecting surface includes a plurality of sub reflecting surfaces connected with each other. A part of the sub reflecting surfaces is substantially parallel to the light incident surface, and the other sub reflecting surfaces are substantially perpendicular to the light incident surface.

[0011] According to an embodiment of the invention, the reflecting surface includes a plurality of sub reflecting surfaces connected with each other. A part of the sub reflecting surfaces is substantially parallel to the light incident surface, another part of the sub reflecting surfaces is sUbstantially perpendicular to the Ught incident surface, and the other sub reflecting surfaces form an oblique angle with the light incident surface.

[0012] According to an embodiment of the invention, the reflecting surface is a curved reflecting surface.

[0013] According to an embodiment of the invention, a gap exists between the tight emitting device and the light incident surihce of the light guide plate.

[0014] According to an embodiment of the invention, the light beams emitted from the light emitting device have a primary light beam, and the primary light beam is substantially parallel to a normal of the light incident surface.

[0015] According to an embodiment of the invention, the light beams emitted from the light emitting device have a primary light beam, and the primary light beam and a normal of the light incident surface form an angle.

[0016] According to an embodiment of the invention, the abovementioned angle is between 130 and 200.

[0017] According to an embodiment of the invention, the illumination apparatus ffirther includes an optical plate. The optical plate is connected with the frame and covers the exit of the light guiding channel.

[0018] According to an embodiment of the invention, the optical plate further includes a diffusion plate, a color filter plate, a translucent plate, or a transparent plate.

[0019] According to an embodiment of the invention, the illumination apparatus further includes an external channel connected with the frame. The external channel has an entrance and an exit, and the entrance of the exteruia channel is connected with the exit of the light guiding channel to guide the portion of the light beams passing through the light guiding chann& out of the exit of the external channel.

[0020] According to an embodiment of the invention, the external channel has a 1 5 sidewall between the entrance of the external channel and the exit of the external channel, and the sidewall of the external channel is a reflecting surface.

[0021] According to an embodiment of the invention, the illumination apparatus father includes at least one optical film. The optical film is disposed in the frame and above the light emergent surface of the light guide plate.

2.0 [0022] According to an embodiment of the invention, the illumination apparatus further includes at least one reflecting element. The reflecting element is disposed between the light emitting device and the light incident surface of the light guide plate and is adjacent to the optical film, [0023] According to an embodiment of the invention, the illumination apparatus further includes a reflecting plate. The reflecting plate is disposed in the frame and below the light guide plate.

[0024] As described above, an illumination apparatus provided by the invention has at least one light guiding channel. Thus, the illumination apparatus in the invention is capable of providing side-lighting.

[0025] These and other exemplary embodiments, features, aspects, and advantages of the invention will be descr bed and become more apparent from the detailed description of exemplary embodiments when read in conjunction with accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are included to provide a thither understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0027] FIG. 1 A is a schematic vie*%V of an illumination apparatus according to a first embodiment of the invention.

[0028] FIG. lB is an enlarged view of an area A in FIG. IA.

[0029] FIG. 2 is a partial cross-sectional vtew along line -1' in FIG. 18.

[0C30] FIG.3is a partia.i cross-sectional view of an illumination apparatus according to a second embodiment of the invention.

[003 1] FIG. 4 is a partial crosssectional view of an illumination apparatus according to a third embodiment of the invention.

[0032] FIG. 5 is a partial cross-sectional view of an dlurmnation apparatus according to a fourth embodiment of the invention.

[0033] FIG. 6 is a partial cross-sectional view of an illumination apparatus according to a fifth embodiment of the invention.

DESCRiPTION OF THE EMBODIMENI'S

[0034] Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are iflustrated in the accompandng drawings.

Wherer possible, the same reference numbers are used in the drawings and the

description to refer to the same or like parts.

[First Embodiment] [0035] FIG IA is a schematic view of an illumination apparatus according to the first embodiment of the invention. FIG. lB is an enlarged view of an area A in FIG. IA, and FIG, 2 is a partial cross-sectional view along line I-I' in FIG, 1W Referring to FIG. li\, FIG. 113, and FIG. 2, the illumination apparatus 100 in the present embodiment includes a frame 110, a light guide plate 120, and a light emitting device 130, The light guide piate 120 is disposed in the flame 110. The light emitting device 130 is disposed between the frame 110 and the light guide plate 120. The frame 110 has a light guiding channel 112, The light guide iiate 120 has a light incident surface 122 and a light emergent surface 124. The light emitting device 130 is suitable for emitting a light beams L.A poTtion (Li) of the light beams L enters the light guide plate 120 through the light incident surthee 122 and leaves the light guide plate 120 through the light emergent surface 124, and another portion (L2) of the light beams L enters the light guiding channel 112 through the entrance 11 2a of the light guiding channel 112 and leaves the frame 110 through the exit 112b (not shown in FIG. IA and FIG. 1B) of the light guiding channel 1.12. The light beam L2 leaving the frame 110 through the exit 1 12h of the light guiding channel 112 allows the illumination apparatus 100 in the present emhodi.men.t to have the side-lighting capahihty. In other words, the illumination apparatus 100 in the present embodiment has both front-lighting (i.e., the downward lighting illustrated in FIG. 2) and side-lighting capabilities.

[0036] In the present embodiment, to supply appropriate driving voltage and driving current to the illumination apparatus 100, the illumination apparatus 100 frirther includes an transfotmer 10 (as shown in FIG. IA) to turn on/off the illumination apparatus 100. The illumination apparatus 100 is usually installed on the ceiling for illuminating an indoor space. However, the invention is not limited thereto, and the illumination apparatus 100 in the present embodiment may also be used for illuminating an. outdoor space or any other environment. As shown in FIG. 2, the illumination apparatus 100 in the present embodiment is an edge type illumination apparatus.

[0037] In the present embodiment, the frame 110 is made of a plastic material and for supporting the light guide plate 120 and the light emitting device 130, and the frame has the light guiding channel 112. The light guiding channel 112 serves as the path of the other portion (U) of the light beams L thr leaving the frame 110.

10038] In the present embodiment, the light guide plate 120 is made of a iight-transmissive material, such as polymethyl methacrvlate (PMMA) or polycarbonate (PC). The portion (LI) of the light beams L enters into the light guide plate 120 thr-ough the light incident surface 122 of the light guide plate 120 and. exits through the light emergent surface 124 of the light guide plate 120, so that a front-lighting pumose (i.e., the downward lighting illustrated in FIG. 2) is achieved.

[0039] in the i" embodiment, the light emitting device 130 is a light emitting diode (LED) light bar. For example, the LED light bar includes a canying substrate 130a and a plurality of LED 130b. The LEDs 130h are ananged on the cartying substrate I 30a in a linear manner and is electrically connected with the carrying substrate 1 30a, In the present embodiment, the carrying substrate 1 30a is a metal core printed circuit hoard (MC-PCI3), ceramic printed circuit board, a FR-4 printed circuit board, a FR-5 printed, circuit board, or any other circuit board with high thermal conductivity. In FIG.2, the LEDs I 30h are top-view LET) packages, for example.

However, the type of the light emitting device 130 is not limited in the present embodiment. and a side-view LED package may also be adopted in the present embodiment.

[0040] As shown in FIG. 2, besides the light guiding channel 112, the frame 110 in the present embodiment fiwther has a light guide plate accommodating space 1 20a and a light emitting device accommodating space 1 $Oc. The light guide plate 120 is disposed in the light guide plate accommodating space 120a, and the light emitting device 130 is disposed in the light emitting device accommodating space 13Cc, lin addition, the entrance Ii 2a of the light guiding channel 112 is connected with the light guide plate accommodating space 120a arid the light emitting device accommodating space 13Cc, and the entrance 112a of the light guiding channel 112 is between the light guide plate accommodating space 120a and the light emitting device accommodating -a., space 130c, [0041] in the present embodiment, the light guiding channel 112 has a sidewall 114 between the entrance I 12a of the light guiding channel 112 and the exit 112b of the light guiding channel 112. The sidewall 114 of the light guiding channel 112 is a reflecting surface. Herein the reflecting surface can be implemented by forming a reflecting coating or attaching a reflector. In addition, the reflecting surface includes a plurality of sub reflecting surfaces 114a and sub reflecting surfaces 114h connected with cacti other. T lie sub reflecting surfaces 1 14a are substantially parallel to the noirnal Ni of the light incident surface 122, and the sub reflecting surfaces 1 14b are substantially perpendicular to the nonnal Ni of the light incident surface 122. The portion (LI) of the light beams L leaves the light guide plate 120 through die light emergent surface 124, and the other portion (L2) of the light beams L enters into the light guiding channel 112 through the entrance 11 2a, then is reflected between the sub reflecting surfaces II 4b arid I 14a. and eventually leaves the frame 110 through the exit 1 12b of die light guiding channel 112. Thereby, the illumination apparatus 100 in the present embodiment has both front-lighting (i,e., the downward. lighting illustrated, in FIG. 2) and side-Jighting capabilities.

[0042] Additionally, in the present embodiment, there is a gap 01 between the light emitting device 130 and the light incident surface 122 of the light guide plate i20. The gap 01 affect.s the amount of light entering into the light guide plate 120. When the gap (H is reduced, the portion (LI) of the ligh.t beams L entering the light gtide plate increases, and accordingly the amount of the light beam Ll leaving through the light emergent surthce 124 of the light guide plate 120 increases while the amount of the light beam L2 kaving thrnugh the exit I 12b of the light guiding channel 112 decreases.

Contrarily, when the gap Ci is increased, the portion (Li) of the light beams L entering the light guide plate 120 decreases, and accordingly the amount of the light beam LI leaving through the light emergent surface 124 of the light guide plate 120 decreases while the amount of the light beam L2 leaving through the exit 112b of the light guiding channel 112 increases. Thereby, in. the present embodiment, the dimension, of the gap GI can he adjusted according to different design requirement.

[0043] To be specific, the light beams L emitted from the light emitting device 130 iii the present embodiment have a primary light beam Si. The primary light beam Si is substantially parallel to the normal NI of the light incident surface 122. Accordingly, a great portion (H) of the light beams L enters into the light guide plate 120 through the light incident surtiiee 122 and leaves the light guide plate 120 through the light emergent surface 124 along the primary light beam SI. A small patton (12) of the light beams L enters into into the light guiding channel 112 through the entrance 112a, is reflected by the sub reflecting surfaces 114h and 114a. and kaves the flame 110 through the exit I 12b of the light guiding channel 112 The light beam LI leaving the light guide plate through the light emergent surface 124 provides a fronthghting capability, while the light beam L2 leaving the frame 110 from the light guiding channel 112 provides a side-lighting capability. Thus, the illumination apparatus 1 00 in the present embodiment has both the front-lighting (i.e., the downward lighting illustrated in FIG. 2) and the side-lighting capabilities.

[0044] In the present embodiment, a ret] ecting plate 140 is disposed in the frame and below the light guide plate 120 (i.e., opposite to the light emergent surface 124).

Generally, the reflecting plate 140 is a reflecting coating or a reflector. The reflecting plate 140 reflects part of the light beam LI leaving from the bottom surface of the light guide plate 120 (La, the opposite side of the light emergent surface 124) back into the light guide plate 120, so that the utilization efficiency of the light beam LI is improved and accordingly the amount of the front.4ighting (i.e, the downward lighting illustrated in FIG. 2) is increased.

[0045] In the present embodiment, the illumination apparatus 100 further includes one or more optical films 150, The optical films 150 are disposed in the frame 110 and above the light emergent surface 124 of die light guide plate 120. For example, the optical films 150 are adhered on the light emergent surface 124 of the light guide plate by using an optical adhesive and are extended into the gap GI, or the optical films are directly placed on the light emergent surface 124 of the light guide plate 120 without using any optical adhesive. For example, the optical films 150 may include a lower diffuser, a lower prism sheet, an upper prism sheet, and an upper diffuser and are sequentially stacked on the light guide plate 120. The optica' films 150 may include at least one of a lower diffuser, a lower prism sheet, an upper prism sheet, and an upper diffuser. With the optical films 150, the brightness and/or the uniformity of the illumination apparatus 100 are improved.

[0046] In the present embodiment, the illumination apparatus 100 may selectively include at least one reflecting element 115. The reflecting element 115 is disposed between the light emitting device 130 and the light incident surface 122 of the light guide plate 120 and is adjacent to the optical films 150. The reflecting element II 5 may be a reflecting coating or attaching a reflector. The reflecting element 115 can

-I

reflect the light beameffused from the light emitting device 130 to the light incident surface 122 of the light guide plate 120, so that the utilization efficiency of the light beam emitted by the light emitting device 130 is improved.

1:00471 in the present embodiment, the illumination apparatus 100 may selectively include an optical plate 1 60, The optical plate 160 is connected with the frame 110 and covers the exit II 2h of the light guiding channel 112. The optical plate 160 may be a difThsion plate, a color filter plate, a translucent plate, or a transparent plate. The diffusion plate can refract, reflect, and disperse the light beam L2 at different angles and in different directions. so that a light diffusion effect and an uniform side-lighting can be achieved. The color filter plate allows narrow hand light to pass such that the light beam L2 can present a specific color. The translucent plate can be used for controlling or modulating the brightness of the side-lighting. Moreover, each of the transparent plate, the diffusion plate, the color filter plate, and the translucent plate conies with a dustproof function.

[0048] lhe other embodiments of the invention will be described below.

Throughout following embodiments, like reference numerals refer to light elements, and the same elements are not described twice.

[Second Embodiment] [0049] FiG. 3 is a partial cros&.sectional view of an illumination apparatus according to the second embodiment of the invention. Referring to FIG. 2 and FIG. 3, the illumination apparatus 100a in the present embodiment is similar to the illumination apparatus 100 in the first embodiment except that in the light emitting device 130' of the present embodiment, the primary light beam Si forms an angle Al with the normal NI of the light incident surface 122, and the primary light beam Si is parallel to the normal NI of the light incident surface 122.

[0050] In the present embodiment, the ratio of the light beam Li to the light beam L2 can be changed by adjusting the angle Al of the light emitting device 130'. In other words, in the present embodiment, the amount of the light beam Li can be appropriately reduced and the amount of the light beam L2 can he appropriately increased by adjusting the angle Al of the light emitting device 130'. In the present embodiment, the angle Al is between 130 and 200.

[Third Embodiment] [0051] FlU. 4 is a partial cross'-sectional view of an illumination apparatus according to the third embodiment of the invention. Referring to FIG. 3 and FIG, 4, the illumination apparatus 10Db in the present embodiment is similar to the illumination apparatus 100a in the second embodiment except that the reflecting surface includes a plurality of sub reflecting surfhces 114a' and sub reflecting surfaces 114h' connected with each other. The sub reflecting surfaces 114a' are substantially parallel to the normal NI of the light incident surface 122, and the sub reflecting surfaces 11 4b' form an oblique angl.e A2 with the light incident surface 122. It should he noted that the oblique angle A2 is not equal to 90° or 180°.

[0052] In the present embodiment, after a portion (L2) of the light beams L enters into the light guiding channd 112 through the entrance 11 2a, with the oblique angle A2 between the sub reflecting surfaces I 14b' and the light incident surface 122, the &eater portion (L2) of the light beams L is reflected towards the exit Ii 2h of the light guiding channel 112 along the light guiding channel 112, and the light beam Li is guided out of the frame 110 in a direction perpendicular or almost perpendicular to the light incident surface 122, so that the reflected number of times of the portion (L2) of the light beams L is reduced and the amount of the side4ighting is increased. On the other hand, in the present embodiment, the disposition of the light emitting device 130' is not limited. In an alternate embodiment, the light emitting device 130' may also be disposed as the light emitting device 130 in the first embodiment [Fourth Embodiment] [0053] FIG. 5 is a partial crosssectionaI view of an illumination apparatus according to a fourth emhodimer.it of the invention. Referring to FIG. 4 and FIG. 5, the illumination apparatus lOOc in the present embodiment is similar to the illumination apparatus 10Gb in the third embodiment except that in the present embodiment, the sub reflecting surfaces 1 14c' are curved reflecting surfaces. After a portion (L2) of the light beams L enters into the light guiding channel 112 through the entrance I 12a, with the curved sub reflecting surfaces 114c', the greater portion (L2) of the light beams L is reflected. towards the exit 11 2h of the ligh.t guiding channel 112 along the light guiding channel 112, and the light beam Li is guided out of the frame 110 and collected in a direction perpendicular or almost perpendicular to the light incident surface 122, so that the reflected number of times of the portion(L2) of the light beams L is reduced and the amount of the side-lighting is increased.

[0054] On the other hand, in the present embodiment, the light emitting device 130' may not he disposed so that the angle Al is formed between the primary light beam Si and the normal Ni of the light incident surface 122. Instead, the light emitting device 130' may also be disposed as the light emitting device 130 in the first embodiment. -4-

[Fifth Embodiment] [0055] FIG. 6 is a partial crosssectional view of an illumination apparatus according to the fifth embodiment of the invention. Refen-ing to both FIG. 2 and FIG. 6, the illumination apparatus I OOd in the present embodiment is similar to the illumination apparatus iOOa in the second embodiment, and the major difference between the two illumination apparatuses is that the illumination apparatus I OOd in the present embodiment further includes an external channel 1 70, Herein the external channel 170 is connected with the frame ll{). To he specific, the external channel 170 has an entrance 1 iDa and an exit 17Db. The entrance I 70a of the external channel 170 is connected with the exit 1 12b of the light guiding channel 112. The external channel has a sidewall 114." between the entrance I 70a of the external channel 1.70 and the exit 1 7Db of the external channel 1 70. The sidewall 114" of the external channel 170 is a reflecting surface, and which guides a portion (L2) of the light beams I. (which is guided by the light guiding channel 112 of the frame 110) from the entrance I 70a of the external channel 170 out of the exit 17Db of the external channel 170, Herein a reflecting surface may be implemented as a reflecting coating or by attaching a reflector.

Namely, in the illumination apparatus I DOd of the present embodiment, the exit II 2b of the light guiding channel 112 is formed at the bottom side of the frame 110, so that the overail structural strength of the illumination apparatus lOOd is maintained. Surely, in the present embodiment, a portion (Ll) of the light beams L enters into the light guide plate 120 through the light incident surface 122 and leaves the light guide plate 120 through the light emergent surface 124 to provide the front-lighting (i.e., downward lighting) capability. M general, the illumination apparatus I ODd in the present embodiment has both front$ighting and side4ighting capabilities.

[0056] On the other hand, in the present embodiment, the disposition of th.e iigh.t emitting device 130 is not limited. In an alternate embodiment, the light emitting device 130 may also be disposed as the light emitting device 130' in the second embodiment, F0057] The shape or number of the exit 112b of the light guiding channel 112. or the exit 17Gb of the external channel 170 is not limited in the invention and the shape or brightness of the portion (LI) of the light beams 1. emitted from the side can he adjusted with different shapes or numbers of the exits. Supporting ribs may he disposed at the exit I 12b or the exit I 70b at intervals to increase the mechanical strength.

[0058] As described above, in an illumination apparatus provided by an embodiment of the invention, the -frame has a light gukiing channel such that the iFtumination apparatus offers the sidelighting capability. in addition, the ratio of the front lighting to the side-lighting can be changed by adjusting the distance between the light emitting device and the light guide plate or the angle between the primary light beam of the light emitting device and the normal of the light incident surface. On the other hand, by designing part of the reflecting surface of the si.dewa[l of the ight guiding channel as an inclined reflecting sw-face or a curved reflecting surface, the number of times that the light beam is reflected in the light guiding channel is reduced, and accordingly the amount of the sidelighting is increased.

[0059] It will be apparent to those skilled in the art that various modifications and variations can he made to the structure of the invention without departing from the scope or spirit of the invention. In view of the tbregoing, it is intended that the invention cover modifications and variations of this invention pmvided they fall within the scope of the following claims and their equivalents. -:17-