TW201237327A - Illumination apparatus - Google Patents

Abstract

An illumination apparatus includes a light guide plate, a first light bar, a second light bar, a first reflection sheet, and a second reflection sheet. The light guide plate has a light emitting surface, a bottom surface opposite to the light emitting surface, and N side surfaces connected the light emitting surface and the bottom surface, where N ≥ 4. The first light bar is disposed beside one of the side surfaces, and capable of emitting a first beam transmitted along a first optical axis. The second light bar is disposed beside another of the side surfaces, and capable of emitting a second beam transmitted along a second optical axis. The first beam and the second beam are transmitted to the light guide plate respectively through the corresponding side surfaces, and transmitted outward from the light guide plate through the light emitting surface. The first optical axis and the second optical axis are not parallel. The first reflection sheet and second reflection sheet are respectively disposed beside the side surfaces opposite to the first light bar and the second light bar.

Description

201237327 π ζυ /4 37164twf.doc/I VI. Description of the Invention: [Technical Field] The present invention relates to a lighting device and particularly relates to a lighting device that provides a planar light source. 1A is a top plan view of a conventional illumination device, FIG. 1B is a light intensity distribution diagram of a conventional light-emitting diode, and FIG. 1C is a schematic cross-sectional view taken along line I-Ι of FIG. 1A. Referring to FIG. 1A , in the conventional illumination device 100 , two light emitting diode (LED) light strips 110 , 120 are symmetrically placed on opposite sides of the light guide plate 130 , thereby The optical axes 01, 02 of the light-emitting diodes 112, 122 are made parallel to each other, that is, the angle between the optical axes 〇1, 02 is a twist. However, as shown in FIG. 1B, since the light intensity distribution LI of the light-emitting diodes 112, 122 is the strongest in the normal direction N1 (corresponding to the angle 〇), as shown in FIG. 1C, when the symmetric structure is applied to the optical path, When a short luminaire (for example, a downlight or a small ceiling chandelier), a plurality of light beams L1 transmitted in the normal direction N1 (or the optical axis 〇1) of the light-emitting diode strip 110 directly penetrate the side surface 134 and transmit The opposite light-emitting diode strips 120 ′ thus reduce the light intensity provided by the light-emitting surface 132 , thereby reducing the light use efficiency of the light-emitting diode strips 11 , and increasing unnecessary cost and cost. _In addition to this, the prior art also provides several techniques related to lighting devices. The prior art of U.S. Patent Publication No. 20100027293 discloses a light guide plate having a plurality of curved grooves for coupling a light source to provide uniform surface light.

201237327 ΚΙ 2074 37164twf.doc/I source, where the light-emitting diodes are arranged at the corners of all the light guide plates. U.S. Patent No. 6,464,366 and U.S. Patent Publication No. 20060269213 disclose that the opposite end of the light incident surface of the light guide plate is attached to the reflective sheet to increase the light source utilization, but both expose only one light emitting diode and the light emitting diode. It is only placed on the side of the light guide. Further, the Republic of China Patent No. M339773 discloses a light guide plate and a heat dissipating device thereof, wherein the light emitting diode lamp strips are disposed on two opposite sides of the light guide plate. The Republic of China Patent No. M329739 discloses an umbrella type light guide comprising a plurality of light emitting diodes surrounding the light guide plate. The Republic of China Patent No. M3223021 also discloses a light steel frame t_Bar polar body luminaire. L praise content] = Ming provides - a kind of lighting device with good light use efficiency.技特^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The light-emitting surface reflection sheet and the two-reflection sheet. The light guide surface and the side surface of the bottom surface, the surface 2 and the side of the joint are connected, and are suitable for emitting the second light=two first light strips disposed on the side surface, and the second light strip is disposed on the side surface/D—the first The -first beam transmitted by the optical axis. A second light 2 transmitted by the shaft = the other side and adapted to emit along a second beam. The first beam and the second beam respectively correspond to each other

The side surface of 201237327 r 1 ]7164twf.doc/I enters the light guide plate and is transmitted outside the light guide plate via the light exit surface. The first-optical axis is not parallel to the second light. The first-reflecting sheet and the second reflecting sheet are respectively disposed on the side surface opposite to the first light strip and the second light strip. The ^th-reflection; i and the second reflective sheet may be formed into a body or separately disposed on the surface; At least the following advantages or effects can be achieved based on the above-described embodiments of the present invention. In the implementation of the present invention, since the first optical axis corresponding to the first light bar and the second optical axis corresponding to the second light bar are not parallel to each other, and the reflective sheet is disposed opposite to the first light bar and the second light wire _ On the surface, it is possible to reduce the probability that the first beam and the second filament exit from the side surfaces facing the first and second strips, thereby enabling the illumination device to have good light use efficiency. The above-described features and advantages of the present invention will become more apparent from the following description. The above and other technical contents, features and effects of the present invention will be apparent from the following detailed description of the preferred embodiments. The directional terms mentioned in the following embodiments, such as up, down, left, right, front or back, etc., are only directions referring to the additional drawings. Therefore, the directional terminology used is for the purpose of illustration and not limitation. 1A is a plan view of a lighting device 2A according to a first embodiment of the present invention, and FIG. 2B is a cross-sectional view taken along line 11-11 of FIG. Referring to FIG. 2A and FIG. 2B simultaneously, the illumination device 200 includes a light guide plate 21, a light bar 22,

201237327 f 12074 37164twf.doc/I 230 and a reflection sheet 240, wherein the reflection sheet 240 is, for example, a white reflection sheet. The light guide plate 210 has a light-emitting surface S1, a bottom surface S2 opposite to the light-emitting surface si, and N side surfaces (for example, side surfaces S3 to S6) connecting the light-emitting surface S1 and the bottom surface S2, wherein N24. In the present embodiment, N is, for example, 4, and the light guide plate 210 is, for example, a regular square. The illumination device 200 of the present example is, for example, a short path optical device, i.e., a light beam having a short transmission distance in the light guide plate 21A. In detail, the length D1 of the side surface S3 to the side surface S5 of the light guide plate 210 is, for example, less than or equal to 30 cm, and the length D1 described above corresponds to the optical path length of the illumination device 200. However, the invention is not limited to illumination devices with short path lengths. The light bar 220 is disposed beside the one side surface S3 of the side surfaces S3 to S6, and is adapted to emit the light beam L3 transmitted along the optical axis 03. The light bar 230 is disposed beside the other side surface S4 of the side surfaces S3 to S6, and is adapted to emit the light beam L4 transmitted along the optical axis 〇4. The light beam L3 and the light beam L4 enter the light guide plate 210 via the corresponding side surfaces S3 and S4, respectively, and are transmitted to the outside of the light guide plate 210 via the light exit surface S1. Since the light beam L3 enters the light guide plate from the side surface S3, S3 is a light incident surface corresponding to the light strip 220; likewise, the light beam L4 enters the light guide plate from the side surface S4, so S4 is a light incident surface corresponding to the light strip 230. The optical axis 03 and the optical axis 04 are not parallel to each other', that is, the optical axis 〇3 and the optical axis 〇4 have an angle <9 1, wherein the angle Θ1 ranges from 30 degrees to 150 degrees, and in this embodiment. The angle of loss 0 1 is, for example, 90 degrees. The reflection sheet 240 is disposed on the side surfaces S3 to S6 opposite to the light strip 22 and the light strip 230, that is, the side surfaces S5 and S6. In addition, the light strips 22A, 230 respectively include a plurality of light emitting diodes 222, 232, wherein the light intensity of the light emitting diodes 222, 232 201237327

FI 2074 37164twf.doc/I degree distribution can be the strongest in the normal direction, that is, the smaller the angle of the optical axis of the light-emitting diodes 222, 232 (for example, at a zero angle), the greater the relative luminous intensity, for example, Positive Light Emitting Diode (t〇p_view LED) ^ The designer can also adjust the color temperature values of the LEDs 222 and 232 to achieve different color temperature effects. In addition, as shown in Fig. 2B, the illumination device 200 further includes a plurality of microstructures 250, and the microstructures 250 are disposed on the bottom surface S2. As shown in Fig. 2A, the distribution pattern a of the microstructures 250 on the bottom surface S2 is, for example, a circle, so that the illumination device 200 can provide a circular light shape. In other embodiments, however, the distribution pattern A of the microstructures 250 may be other shapes, such as four sides, <RTI ID=0.0>>> On the other hand, the microstructures 250 of the present example are, for example, arranged at unequal intervals. In detail, the number density of the microstructures 250 near the light strips 220 and the light strips 230 is less than the number density at the distance from the light strips 220 and the light strips 230 to achieve a uniform light output. As shown in Fig. 2B, the microstructures 250 are adapted to destroy the total reflection of the light beam L2 such that a portion of the light beam L2 penetrates the light surface S1 and is transmitted outside the light guide plate 210 to achieve uniform light output and provide a planar light source. The microstructures 250 are, for example, bumps, and the bumps are, for example, printed dots or fabricated using inkjet techniques. Referring to FIG. 2A and FIG. 2B simultaneously, since the light bars 220 and 230 of the present embodiment are respectively disposed on the side surfaces S3 and S4 of the light guide plate 21A in an asymmetric manner, most of the light beams L3 are transmitted along the optical axis 〇3. The light beam that does not penetrate from the side surface S4 beside the light bar 23' can only penetrate from the side surface S4 beside the light bar 230. Other than that, due to 201237327

PT2074 37164twf.doc/I The reflection sheet 240 is disposed on the side surface S5 of the light strip 220 and its light incident surface S3. Therefore, when the light beam L3 is transmitted to the side surface S5 along the optical axis 03, the reflection sheet 240 reflects the light beam L3. Returning to the light guide plate 210. When the light beam L3 of Fig. 2B is reflected to the microstructure 250, the microstructure 250 destroys the total reflection of the light beam L3, and the light beam L3' is transmitted to the outside of the light guide plate 21 via the light exit surface S1. Therefore, the illumination device 200 of the present embodiment can provide a planar light source that is more yfj-free than the case where the light beam L1 directly penetrates the surface 134 of Fig. 1 and causes less light beam L1 to exit from the light exit surface 132. Similarly, the asymmetric arrangement of the light strips 220, 230 can also avoid the fact that most of the light beam L4 transmitted along the optical axis 〇4 in FIG. 2A penetrates from the side surface S3 of the light strip 22, that is, A small portion of the beam that deviates from the normal direction will penetrate from the side surface S3 beside the light bar 220. In addition, a reflection sheet 240 is disposed on the side surface S6 opposite to the light strip 230 and the light incident surface S4, so that when the light beam L4 is transmitted to the side surface S6 along the optical axis ,4, the reflection sheet 240 transmits the light beam. L4 is reflected back into the light guide plate 21, so that the light beam L4 is used again, thereby improving the light use efficiency. Since the light intensity distribution of the light-emitting diodes 222 and 232 is stronger as it is closer to the normal direction thereof, the lighting device 200 of the present embodiment can effectively utilize the light-emitting diodes 222 and 232 close to the normal direction thereof. The beam (such as the beam [3, L4), can provide good light usage and high illumination. In the present embodiment, as shown in FIG. 2A, the reflection sheets 240 respectively disposed on the side surfaces S5 and S6 are monolithic (ie, integrally formed); in other embodiments, the reflection sheets 240a on the side surfaces S5 and S6, 240b is separately set (i.e., not integrally formed) as shown in Fig. 2C. 201237327

PT2074 37164twf.doc/I Table 1 shows the illumination device 200 of the present embodiment and the optical noise table of FIG. 1A 100. It should be noted that the data (10) and (4) in the following Table 2 are invented by the limited forest, and any person having ordinary knowledge in the technical field after referring to the present invention may change its parameters or 适当 appropriately, but still It should be within the scope of the invention. — (Table 1) How to place two light bars ------------—One angle between two optical axes (degrees) -----—— Figure 1 对称 Symmetrical placement ----- -- 0__ —^ 864.5 ------ Figure 2 非 对 _ _ _ _ _ 90 — 12 864.5 Optical path length (cm) Light output of the LED (lumen) Light-emitting diode Current (mA 250 250 pp) Light intensity of the illuminating device (lumens) 655.9 714.1 Light use efficiency 75.87% 82.6% Relative light use efficiency 100% 108.87% As can be seen from Table 1 'This embodiment uses light bars 220 and 230 When it is asymmetrically disposed beside the side surfaces S3 and S4 of the light guide plate 210 (that is, the angle of the optical axis is 0 degrees is 90 degrees), the light use efficiency of the illumination device 2 can be improved, and the brightness is provided. Plane light source. As shown in the embodiment of Table 1, the light use efficiency of the illumination device 200 is about 9% higher than that of the conventional illumination device. Fig. 3Α and Fig. 3Β are the guide of the light guide plate and the long path length of the light beam in the short path length

201237327 PT2074 37164twf.doc/I Schematic diagram of transfer comparison in the light panel. For convenience of comparison, the light guide plate 310 of the short path and the light guide plate 410 of the long path are superimposed on the same figure. As described above, the short optical path indicates that the traveling distance of the light beam within the light guide plate 310 is short. Referring to FIG. 3A first, in the embodiment, the length D2 of the light guide plate 310 is, for example, less than 30 cm. As shown in FIG. 3A, a light strip 320 is disposed adjacent to the light guide plate 310 and the light guide plate 410, and the light strip 320 includes a light emitting diode 322. The light-emitting diode 322 is adapted to emit light beams L5, L6. The light beam L5 is a light beam which is not scattered by the microstructure 312 of the light guide plate 31 but is directly transmitted to the opposite side surface S7 and exits the light guide plate 310 through the side surface S7. The light beam L6 is a light beam which is not scattered by the microstructure 412 of the light guide plate 41 but is directly transmitted to the opposite side surface S8 and exits the light guide plate 410 through the side surface S8. As can be seen from FIG. 3A, under the condition that the light-emitting angle 022 of the light-emitting diode 322 is fixed, the light beam [5] surrounds the area surrounded by the light beam L6, and the excess area is Area B in Figure 3. It can be seen that when the optical path of the light guide plate 310 is short (that is, the length D2 is relatively new), a relatively high proportion of the light beam (for example, the light beam L5) directly exits from the opposite side surface S7 of the photodiode 322. The light plate 310 reduces the probability of the light beam exiting the light guide plate 31 from the light exit surface S9, and the overall light use efficiency. Referring to Fig. 3A, when the light beam 17 hits the microstructure of the light guide plate 31, the microstructure 312 destroys the total reflection of the wire L7, so that part of the light beam U' is transmitted in the direction of the side surface S7. 'However, since the light guide plate 31 长度 ^ length D2 the father also 'light beam L7, will directly leave the light guide reverse 310 from the side table Φ S7 and can not continue to transfer inside the light guide plate 31 从而, thereby reducing the light 11 201237327 PT2074 37164twf. The probability that the doc/I beam L7' is scattered by the microstructure 312 and emitted by the light exit surface S9. As a result, the overall light use efficiency is reduced. On the other hand, if the beam! ^ is transmitted in the light guide plate 410. Since the optical path of the light guide plate 41 is long (that is, the length D3 is long), the light beam is scattered once! ^, there is also an opportunity to be scattered again by the microstructure 412 so that part of the light beam L7" can be emitted from the light exit surface S10 of the light guide plate 410. Therefore, as can be seen from Fig. 3A and Fig. 3B, under other conditions, the light beam The light-emitting ratio of the side surface S7 of the light guide plate 31 from the short path length is higher than the light-emitting ratio of the side surface S8 of the light guide plate 41A of the light beam from the long path. In view of this, as shown in FIG. 2A, this embodiment The illuminating device 200 can illuminate the light strips 220 and 230 in the asymmetric manner on the side surfaces S3 and S4 of the light guide plate 210, and attach the reflection sheet to the side surfaces S5 and S6 to reduce the light beam from the light strip 22 The probability of leaving the light guide plate 210 with the opposite side surfaces S5 and S6 of 23〇, thereby improving the light use efficiency. Table 2 is a comparison table of the different characteristics of the illumination devices corresponding to different light paths. The data listed in Table 2 below is not intended to limit the invention, and any person skilled in the art can make appropriate changes to its parameters or settings after referring to the present invention. Within the scope of the invention. B) Anti-shape (cm) regular square quadrilateral -------- 20 is n _ 5 embodiment both sides of the light incident into the light symmetrically placed way in shake asymmetric non-symmetric

S 12 201237327 PT2074 37164twf.doc/I Two-axis cool angle (degrees) 90 0 —---Ί 90 Relative light use efficiency 1 100% 107.26% Ll〇〇% 102.56% As shown in Table 2, regardless of optical path length For 5 cm or 2 cm, the light-using efficiency of the illuminating device with asymmetric illuminating light (Fig. 2A) is higher than that of the illuminating device with symmetrical light bar (Fig. 1A). In addition, when the optical path length of the illumination device is shorter, more light use efficiency can be improved by asymmetrically placing the light bar. In other words, the asymmetric display structure of the embodiment can improve the light use efficiency of the short-length illumination device, thereby reducing the number of the light-emitting diodes to reduce the cost, or reducing the illumination. The driving current of the polar body achieves the effect of energy saving. However, the invention is not limited to illumination devices with short path lengths. On the other hand, since the structure of the asymmetric display light bar of the present embodiment can reduce the consumption time of the illumination device, it also reduces the temperature of the illumination device, thereby avoiding the danger caused by the high temperature of the conventional lamp. Fig. 4A is a plan view schematically showing a lighting device according to a second embodiment of the present invention. A lighting device 5A of FIG. 4A is similar to the lighting device of FIG. 2A, and the main difference is that the light guiding plate of the lighting device 5 has eight sides and the side surfaces S11 to S16 (ie, N = 6). In other words, the shape of the light guide plate 5/0 is hexagonal, and is, for example, a regular hexagon. As shown in Fig. 4A, the strips 2 of the strips 22G are disposed adjacent to the side surfaces S11 and S12, respectively, and the corner angle 19 3 between the strips 7 and 3 is 60 degrees. A reflection sheet 540 is disposed on the side surfaces S14 and S15 of the strip 220 opposite to the light. Except 13

201237327 PT2074 37164twf.doc/I In addition, in the present embodiment, the reflection sheet 540 can be disposed on the side surfaces S13 and S16 of the undisposed light strip 220 and the light strip 230 of the side surfaces S11 to S16. The reflective sheet 540 is adapted to reflect the light beams (eg, the light beams L3 and L4) back into the light guide plate 510, so that the light beam can be utilized again, thereby increasing the probability of the light beam exiting from the light exiting surface S17, thereby improving the light use efficiency of the illumination device 500a. Lighting brightness. As shown in FIG. 4A, in the embodiment of FIG. 4A, the reflection sheets 540 disposed on the side surfaces S14 and S15 are monolithic (ie, integrally formed); in other embodiments, the reflection sheets 540 disposed on the side surfaces S14 and S15. Can be configured separately (ie not integrated). Fig. 4B is a schematic plan view of a lighting device according to another embodiment of the present invention. The illuminating device 500b of FIG. 4B is similar to the illuminating device 500a of FIG. 4A, but the main difference is that the light bar 230 of FIG. 4B is disposed beside the side surface S13 (ie, the light bar 220 is not adjacent to the light bar 230). ), and the angle 0 4 between the optical axis 03 and the optical axis 04 is 120 degrees. Further, the side surfaces S14 and S16 of the light bar 220 and the light bar 230 are disposed with a reflection sheet 540. In addition, the reflection sheet 540 is disposed on the side surfaces 812 and 315 of the unconfigured light strips 220 and the light strips 230 of the side surfaces S11 to S16. The reflection sheet 540 is adapted to reflect the light beams (for example, the light beams L3 and L4) back into the light guide plate 510, so that the light beam can be used again to increase the probability of the light beam emerging from the light exit surface; 517, thereby improving the illumination device 5〇〇b. Light use efficiency. As shown in FIG. 4B, in the embodiment of FIG. 4B, the reflection sheets 540 disposed on the side surfaces S14 to S15 and the side surface S16 are respectively disposed (ie, not integrally formed); in other embodiments, disposed on the side surface S14~ The reflection sheet 54A of the S15 and the side surface S16 may be a single piece (ie, integrally formed, that is, disposed on the side surfaces S14, sl5, and

201237327 PT2074 37164twf.doc/I S16 reflective sheet 540 is integrated). Fig. 4C is a schematic plan view of a lighting device according to another embodiment of the present invention. The illumination device 5〇〇c of Fig. 4C is similar to the illumination device 500a of Fig. 4A, but the main difference is that the illumination device 50〇c of Fig. 4C further includes a light bar 520. The light bar 520 is disposed adjacent to the unconfigured light bar 220 and the light bar 230 of the side surfaces S11 S S16 (for example, the side surface S13), and is adapted to emit the light beam L5 transmitted along the optical axis 05, wherein the optical axis 05 and the optical axis 03 And the optical axes 04 are not parallel to each other. In detail, the angle 0 5 between the optical axis 05 and the optical axis 〇 4 is, for example, 60 degrees, and the angle (0 3+0 5) between the optical axis 〇5 and the optical axis 03 is, for example, 120 degrees. Further, a reflection sheet 540 is disposed on the side surfaces S14'S15 and S16 of the light bar 220, the light bar 230, and the light bar 520. The reflection sheet 54 is adapted to reflect the light beams L3 LL5 back into the light guide plate 510, so that the light beams L3 LL5 can be used again to increase the probability that the light beams L3 LL5 are emitted from the light exit surface S17, thereby improving the light of the illumination device 500c. Use efficiency and lighting brightness. As shown in FIG. 4C, in the embodiment of FIG. 4C, the reflection sheets disposed on the side surfaces S14 and S15 and the reflection sheets disposed on the side surface S16 are respectively disposed (ie, not integrally formed); in other embodiments, The reflection sheets of the side surfaces S14, S15 and the side surface S16 may be a single piece (i.e., integrally formed). The illuminating devices 500a-500c of the embodiment of the present invention, the illuminating devices 500a-500c of the embodiment of FIG. 4A to 4C, further include a plurality of microstructures 550, and are disposed on the bottom surface of the light guide plate 510, and the functions thereof are the same as those of the first embodiment, and details are not described herein again. . Third Embodiment 15

201237327 PT2074 37164twf.doc/I Fig. 5A is a plan view schematically showing a lighting device according to a third embodiment of the present invention. The illumination device 600a of Fig. 5A is similar to the illumination device 5A of Fig. 4A, but the main difference is that the light guide plate 610 of the illumination device 600a has eight side surfaces S18 to S25 (i.e., N = 8). In other words, the shape of the light guide plate 610 is octagonal and is, for example, a regular octagon. As shown in Fig. 5A, the light bar 220 and the light bar 230 are disposed beside the side surfaces S18 and S19, respectively, and the angle 0 6 between the optical axis 03 and the optical axis 〇4 is 45 degrees. Further, a reflection sheet 640 is disposed on the side surfaces S22 and S23 where the light bar 220 and the light bar 230 oppose each other. In addition, in the present embodiment, the reflection sheet 640 is disposed further on the side surfaces S20 to S21 and S24 to S25 of the side surface S18 to S25 where the light strip 220 and the light strip 230 are not disposed. The reflection sheet 640 is adapted to reflect the light beams (for example, the light beams L3 and L4) back into the light guide plate 610, so that the light beam can be utilized again to increase the probability of the light beam emerging from the light exit surface S26, thereby improving the light of the illumination device 6〇〇a. Use efficiency and lighting brightness. As shown in FIG. 5A, in the embodiment of FIG. 5A, the reflection sheets 640 disposed on the side surfaces S22 and S23 are monolithic (ie, integrally formed); in other embodiments, the reflection sheets 640 disposed on the side surfaces S22 and S23. Can be configured separately (ie not integrated). Fig. 5B is a schematic plan view of a lighting device according to another embodiment of the present invention. The illumination device 600b of FIG. 5B is similar to the illumination device 6A of FIG. 5A, but the main difference is that the light bar 230 of FIG. 5B is disposed beside the side surface S20, and the optical axis 〇3 and the optical axis 〇 The angle θ 7 between the four is 90 degrees. Further, the side surfaces S22 and S24 opposite to the light bar 230 and the light bar 230 are provided with a reflection sheet 640. In addition, the reflection sheet 64 is disposed on the side surfaces S19 to S25 and the side surfaces S19 and S21 of the light strip 230.

201237327 PT2074 37164twf.doc/I S23 and S25. The reflection sheet 640 is adapted to reflect the light beams (for example, the light beams L3 and L4) back into the light guide plate 610, so that the light beam can be utilized again to increase the probability of the light beam exiting from the light exit surface S26, thereby improving the light use efficiency of the illumination device 600b. Lighting brightness. As shown in FIG. 5B, in the embodiment of FIG. 5B, the reflection sheets 640 disposed on the side surfaces S22 and S24 are respectively disposed (ie, not integrally formed); in other embodiments, the reflection sheets disposed on the side surfaces S22 and S24. The 640 may be a single piece (i.e., integrally formed, that is, the reflection sheets 640 disposed on the side surfaces S22, S23, and S24 are integrated). Fig. 5C is a schematic plan view of a lighting device according to another embodiment of the present invention. The illumination device 600c of FIG. 5C is similar to the illumination device 600b of FIG. 5A, but the main difference is that the light bar 230 of FIG. 5C is disposed beside the side surface S21, and the angle between the optical axis 03 and the optical axis 04 is <9 8 is 135 degrees. Further, the side surfaces S22 and S25 of the light bar 220 opposed to the light bar 230 are provided with a reflection sheet 640. In addition, the reflection sheet 640 is disposed on the side surfaces S19 to S20 and S22 to S25 of the unattached light bars 220 and the light bars 230 on the side surfaces S18 to S25. The reflective sheet 640 is adapted to reflect the light beams (eg, the light beams L3 and L4) back into the light guide plate 610, so that the light beam can be utilized again to increase the probability of the light beam exiting from the light exiting surface S26, thereby improving the light use efficiency of the illumination device 600c. Lighting brightness. As in the first embodiment, the illumination devices 600a-600c of the embodiment of FIGS. 5A to 5C further include a plurality of microstructures 650 and are disposed on the bottom surface of the light guide plate 610. The function is the same as that of the first embodiment, and is no longer Narration. Table 2 is a comparison table of optical characteristics of different light bars (segment number of side surfaces) SQ for different light bars. It should be noted that the following 17

201237327 FI 2074 37164twf.doc/I ^ The data of the three columns is not used to limit the invention of the forest. Anyone who belongs to the technical staff of the 7th Party has the appropriate knowledge of its parameters or settings after referring to the present invention. More action, but the reduction is within the scope of the invention. The shape of the light guide plate is quadrilateral into the light side - both sides __X - J_ Two optical axis central angle (degrees) 0 Relative light use efficiency _ rate 100% 90 107.26% Hexagon sides 0 0% Light 60 103.38% 120 0 101.97% 100% ___ Octagonal light on both sides 45 103.35% 90 104.75% ____ 135 101.76% According to Table 2, 'When the two optical axes 03 and 04 are not parallel to each other, and have an angle, the lighting device can be raised. The light use efficiency, in which the angle is 90 degrees, the light obtained is the most efficient. In detail, compared with the case where the angle between the conventional lamps is 0 degrees or the optical axes are parallel (for example, FIG. 1A), when the angle between the two optical axes 03 and 〇4 is 9 degrees, about 5 to 8% of the light can be used. effectiveness. In addition to this, other angles (such as 45 degrees, 60 degrees or 135 degrees) can also increase the light use efficiency by about 2 to 4%. As can be seen from Table 3, in the above embodiment, when the angle between the two optical axes is about 9 ,, the light use efficiency of the illumination device can be maximized. 201237327 In summary, embodiments of the invention include at least one of the following advantages or benefits. In the embodiment of the present invention, since the light strip is disposed asymmetrically on the side surface of the light guide plate of the short optical path, and the reflective sheet is also disposed on the opposite side surface of the light strip, the light beam can be reduced. From the situation of the opposite side of the light strip, and the probability of the beam emerging from the light exit surface, thereby improving the light use efficiency of the illumination device and providing a planar light source with high illumination brightness, and achieving the effect of Lang energy saving. On the other hand, since the asymmetric arrangement method can achieve good light use efficiency, in the case of achieving the same illumination brightness, the number of light bars or light-emitting diodes of the present invention can be compared with the conventional ones. The luminaires come less, which has the advantage of saving production costs. However, the above description is only a preferred embodiment of the present invention, when π

I-...τ π 卞 the name, or lower limit. ' is not used to limit the upper limit of the number of components. [Simplified illustration] Figure 1 is a top view of a conventional lighting device.

201237327 PT2074 37164twf.doc/I Figure IB is a light intensity distribution diagram of a conventional light-emitting diode. Figure 1C is a schematic cross-sectional view of Figure ία along the line w. Fig. 2A is a plan view schematically showing a lighting device according to a first embodiment of the present invention. 2B is a schematic cross-sectional view taken along line II-II of FIG. 2A. Fig. 2C is a schematic plan view of a lighting device according to another embodiment of the present invention. Fig. 3A is a schematic view showing the transmission of a light beam in a light path of a short path length and a light path of a long path. Fig. 3B is a schematic view showing the comparison of the transmission of the light beam in the light guide plate of the short path length and the light guide plate of the long path length. Fig. 4A is a plan view schematically showing a lighting device in accordance with a second embodiment of the present invention. Fig. 4B is a schematic plan view of a lighting device according to another embodiment of the present invention. Fig. 4C is a schematic plan view of a lighting device according to another embodiment of the present invention. Fig. 5A is a plan view schematically showing a lighting device according to a third embodiment of the present invention. Fig. 5B is a schematic plan view of a lighting device according to another embodiment of the present invention. Fig. 5C is a schematic plan view of a lighting device according to another embodiment of the present invention.

S 20 201237327

PT2074 37164twf.doc/I [Description of main component symbols] 100, 200, 200', 500a to 500c, 600a to 600c: illumination devices 110, 120: LED strips 112, 122, 222, 232, 322, 522 Light-emitting diodes 130, 210, 310, 410, 510, 610: light guide plates 220, 230, 320, 520: light strips 240, 240a, 240b, 540, 640: reflective sheets 250, 312, 412, 550, 650 : microstructures SI, S9, S10, S17, S26: light-emitting surface 134, S3 to S8, S11 to S16, S18 to S25: side surfaces L1 to L7, L2', L3', L7', L7,,: beam 01 ～05: optical axis θ 1 , 03 〜 (9 8 : angle 02: illuminating angle D1 DD3: length A: distribution pattern B: region N1: normal direction LI: light intensity distribution 21

Claims (1)

201237327 ίΊ^υ /4 37164twf.doc/I VII. Patent application scope: 1. A lighting device comprising: a light guide plate having a light emitting surface, a bottom surface opposite to the light emitting surface, and N connecting the light emitting surface and the a side surface of the bottom surface, wherein: a first light strip disposed on one side of the side surfaces and adapted to emit a first light beam transmitted along a first optical axis; - a second light strip disposed on the The other side of the side surface, and the second light beam transmitted along a second optical axis, wherein the first light beam fish; the second light beam respectively enters the corresponding light surface through the corresponding side surface Outside the light guide plate, the first axis of the second axis t is not parallel to each other; >, the second light-first reflection sheet is disposed on the side surface strips; and the second light is opposite to the first light A sheet that is disposed on the side surface strips. For the photo described in the second paragraph of the patent application, the first optical axis has an angle with the second optical axis, and is set to 30 degrees to ISO degrees. The angle of the cool angle is from 3. The photo-reflecting sheet described in item i of the patent application is disposed on the side surfaces, and the light strip is not disposed. Take the * strip light strip and the L丄 application "special! m circumference of the lighting described in item 1 of the plurality of microstructures, placed on the bottom surface. a disambiguation, and further includes 5. The illumination device described in claim 4 of the patent application, wherein the number of the microstructures is close to the first light bar and the second light bar. The density is less than the number density away from the first strip and the second strip. 6. The illumination device of claim 4, wherein the distribution pattern of the microstructures on the bottom surface is a circle. 7. The illumination device of claim 4, wherein the microstructures are bumps. 8. The illumination device of claim 1, wherein the first light strip and the second light strip each comprise a plurality of light emitting diodes, and the light emitting diodes are positive light type light emitting diodes body. 9. The illuminating device of claim 1, further comprising a third light strip disposed adjacent to the side surface of the side surface where the first light strip and the second light strip are not disposed, and is suitable for emitting a third light beam transmitted along a third optical axis, wherein the third optical axis and the first optical axis and the second optical axis are not parallel to each other. 10. The illumination device of claim 1, wherein the length of the light guide plate is less than or equal to 30 cm. 11. The illumination device of claim 1, wherein the first reflective sheet and the second reflective sheet are integrally formed. twenty three