TWI510816B - Optical lens and light-emitting device using the same - Google Patents

Description

Optical lens and light emitting device using same

The present invention relates to an optical lens and a light-emitting device using the same, and more particularly to an optical lens having a total reflection surface and a light-emitting device using the same.

Conventional optical lenses are used to expand the angle of light emitted by the light, thereby expanding the range of illumination of the emitted light. However, the expansion of the angle of light is likely to cause a problem of insufficient light intensity from a small angle, and a dark band phenomenon occurs.

The present invention relates to an optical lens and a light-emitting device using the same, which can supplement the insufficient light intensity of the dark band region.

According to an embodiment of the invention, an optical lens is proposed. The optical lens includes a bottom surface, a light exit surface and a total reflection surface. The total reflection surface extends from the bottom surface to the outside and in the direction of the light exit surface. The light-reflecting angle of the light reflected by the total reflection surface is less than 150 degrees by the total reflection surface to supplement the insufficient light intensity of the dark band region.

According to another embodiment of the invention, a lighting device is proposed. The light emitting device comprises a circuit board, an optical lens and a light emitting element. Optical lens is located at The circuit board includes a bottom surface, a light exit surface and a total reflection surface. The total reflection surface extends from the bottom surface to the outside and in the direction of the light exit surface. The light-reflecting angle of the light reflected by the total reflection surface is less than 150 degrees by the total reflection surface to supplement the insufficient light intensity of the dark band region. The light emitting element is disposed in the optical lens.

In order to better understand the above and other aspects of the present invention, the preferred embodiments are described below, and in conjunction with the drawings, the detailed description is as follows:

100‧‧‧Lighting device

110‧‧‧Lighting elements

120, 320, 420‧‧‧ optical lenses

121‧‧‧ lens body

121b‧‧‧ bottom

121r‧‧‧ Groove

121s1‧‧‧light side

121s2‧‧‧ into the top of the light

121s3‧‧‧Into the light plane

121u‧‧‧Glossy surface

Concave inside 121u1‧‧

121u2‧‧‧ curved surface

122‧‧‧ recess

122s1‧‧‧ total reflection surface

122s2‧‧‧ inside side

122s3‧‧‧ outer boundary surface

130‧‧‧reflector

130b‧‧‧reflective bottom surface

130s1‧‧‧first reflective side

130s2‧‧‧second reflective side

130r‧‧‧ recess

140‧‧‧ boards

240‧‧‧reflecting partition

A1, A2‧‧‧ light angle

A3, A4, A5, A6, A7, A8‧‧‧ angle

C1‧‧‧ center line

C2, C3‧‧‧ connection

DA‧‧‧Dark zone

L1‧‧‧first beam

L2‧‧‧second beam

P1‧‧‧ first intersection

P2‧‧‧ second intersection

P3‧‧‧ third intersection

S1, S2‧‧‧ curve

FIG. 1A is a top plan view of a light emitting device according to an embodiment of the invention.

Fig. 1B is a cross-sectional view taken along line 1B-1B' in Fig. 1A.

Fig. 2 is a graph showing the relationship between the light exit angle and the light output intensity of the light of Fig. 1B.

Fig. 3 is a view showing the field pattern of the second light beam L2 of Fig. 1B.

Fig. 4 is a cross-sectional view taken along line 4-4' in Fig. 1A.

Fig. 5 is a cross-sectional view showing a reflection sheet according to another embodiment of the present invention.

FIG. 6 is a top plan view of a light emitting device according to another embodiment of the present invention.

Figure 7 is a cross-sectional view showing a light emitting device in accordance with another embodiment of the present invention.

Figure 8 is a cross-sectional view showing a light emitting device in accordance with another embodiment of the present invention.

1A and 1B, FIG. 1A is a plan view of a light-emitting device according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line 1B-1B' of FIG. 1A. The light emitting device 100 is, for example, a part of a direct type backlight module, and includes a plurality of light emitting elements 110, a plurality of optical lenses 120, a reflective sheet 130, and a circuit board 140. In addition, the present invention The optical lens 120 and the reflective sheet 130 of the embodiment are not limited to the direct-lit backlight module, and the edge-lit backlight module or other illumination devices other than the backlight module may be applied.

The light emitting element 110 is, for example, a light emitting diode. In this embodiment, a plurality of light emitting elements 110 are disposed on the circuit board 140 and arranged in an array. In another embodiment, the plurality of light emitting elements 110 can be arranged in any shape. The light-emitting element 110 is disposed in the corresponding optical lens 120, so that the light emitted by the light-emitting element 110 can pass through the optical lens 120 to generate light, thereby generating a corresponding optical effect, such as changing the light-emitting angle of the light.

As shown in FIG. 1B, the light intensity of the area DA is insufficient with respect to the periphery, and is therefore called a dark band. The range of the dark band area DA may be greater than the maximum outer diameter of the optical lens 120, but may be smaller than the maximum outer diameter of the optical lens 120. Since the optical lens 120 of the embodiment of the present invention is designed such that the light ray complements the light intensity of the dark band area DA, the range of the dark band area DA shown in FIG. 1B can be reduced or even the entire dark band area DA can be eliminated.

The light outgoing light includes a first light beam L1 and a second light beam L2, wherein the light exit angle A1 of the first light beam L1 is less than +/-75 degrees (or less than 150 degrees). Since the light-emitting range of the first light beam L1 covers the entire dark-band area DA, the insufficient light intensity of the dark-band area DA can be supplemented. In an embodiment, the light exit angle A1 of the first light beam L1 may be between +/- 50 degrees or +/- 70 degrees, the angle range substantially conforming to the angular range of the dark band area DA, such that most or Even the entire first light beam L1 can supplement the insufficient light intensity of the dark band area DA.

Fig. 2 is a graph showing the relationship between the light exit angle and the light output intensity of the light of Fig. 1B. The curve S1 represents a relationship between the light-emitting angle of the light-emitting element 110 and the light-emitting intensity of the optical lens 120 of FIG. 1B, and the curve S2. The relationship between the light-emitting angle of the light-emitting element and the light-emitting intensity of the light emitted by the conventional optical lens is shown. Comparing the curves S1 and S2, it is understood that the first light beam L1 supplements the insufficient light intensity of the dark band area DA due to the design of the total reflection surface 122s1.

As shown in FIG. 1B, the optical lens 120 further includes a lens body 121 and a recess 122. The lens body 121 has a groove 121r, a bottom surface 121b, and a light exit surface 121u. The groove 121r extends from the bottom surface 121b toward the light exit surface 121u. The concave portion 122 extends from the bottom surface 121b of the lens body 121 toward the light exit surface 121u, and includes a total reflection surface 122s1 and an inner side surface 122s2.

By the design of the total reflection surface 122s1 of the concave portion 122, the first light beam L1 penetrates the lens body 121 from the inner side surface 122s2 of the groove 121r, enters the total reflection surface 122s1, and then reflects from the total reflection surface 122s1 to the light exit surface 121u, and then Light is refracted from the light exit surface 121u. Further, due to the design of the total reflection surface 122s1, the light exit angle A1 between the first light beam L1 and the center line C1 reflected from the total reflection surface 122s1 is less than +/- 75 degrees, to supplement the light intensity of the angle range, Further narrow or eliminate the dark zone. The center line C1 here is the geometric center line of the optical lens 120, and the structure of the optical lens 120 can be symmetrical with respect to the center line C1. Further, the optical axis of the light emitted from the light emitting element 110 may substantially coincide with the center line C1.

As shown in Fig. 1B, in the present embodiment, the total reflection surface 122s1 extends outward from the bottom surface 121b and in the direction of the light exit surface 121u. The total reflection surface 122s1 is a curved surface. In the present embodiment, the slope of the total reflection surface 122s1 is gradually decreased from the center line C1 toward the center line C1, so that the light incident on the total reflection surface 122s1 can be totally reflected. In other embodiments, the total reflection surface 122s1 may be constructed by a plane or a combination of a plane and a curved surface. As long as you can make it The light that is incident on the total reflection surface 122s1 may be reflected, and the embodiment of the present invention does not limit the contour of the total reflection surface 122s1.

In addition, the total reflection surface 122s1 and the inner side surface 122s2 intersect at a first intersection point P1 (in the cross section, they intersect at one point, actually intersect at a line). In the present embodiment, the first intersection point P1 is the vertex of the total reflection surface 122s1, and the inner side surface 122s2 extends perpendicularly from the first intersection point P1 to the bottom surface 121b. The groove 121r includes a light incident side surface 121s1 and an light incident top surface 121s2, wherein the light incident side surface 121s1 intersects the light incident top surface 121s2 at the second intersection point P2 (in a cross section, it intersects at one point, actually intersects at a line). An extension of the center line C1 and the bottom surface 121b intersects at a third intersection P3. The angle A3 of the line C3 of the third intersection point P3 and the first intersection point P1 with respect to the bottom surface 121b is smaller than, equal to or larger than the angle A4 of the line C3 of the third intersection point P3 and the second intersection point P2 with respect to the bottom surface 121b. The ratio of the angle A3 to the angle A4 can be determined according to the light intensity required for the dark band. For example, when the dark band area DA is larger than a predetermined range, the angle A3 can be close to, equal to, or even exceed the angle A4 to reflect more of the first light beam L1; when the dark band area DA is smaller than a predetermined range The angle A3 may be smaller than the angle A4 to reflect the less first beam L1. The predetermined range described above is, for example, a ratio of the diameter of the dark strip area DA to the outer diameter of the optical lens 120, such as any value between 0.8 and 1.5.

In this embodiment, the light incident side surface 121s1 of the recess 121r is connected to the light incident top surface 121s2, and extends substantially perpendicularly from the bottom surface 121b toward the light exit surface 121u. In another embodiment, the light incident side surface 121s1 may be inclined with respect to the bottom surface 121b.

In addition, the groove 121r further includes an entrance light plane 121s3, and the light entrance level is The face 121s3 is located at the lowest end of the groove 121r. The center line C1 passes through the light entrance plane 121s3. Since the optical axis substantially coincides with the center line C1, light traveling along the optical axis can be incident on the light incident plane 121s3. In addition, due to the planar design of the light incident plane 121s3, light traveling along the optical axis can pass through the light incident plane 121s3 and penetrate the lens body 121, and then emit light through the light exit surface 121u.

As shown in FIG. 1B, the light-emitting surface 121u includes a concave surface 121u1 and a curved surface 121u2, wherein the curved surface 121u2 is located at the bottom of the light-emitting surface 121u and is connected to the concave surface 121u1. The curved surface 121u2 can improve the formability or manufacturability (relative to the sharp angle) of the light-emitting surface 121u. Further, due to the contour design of the light-emitting surface 121u, the light-emitting angle A2 of the second light beam L2 emitted from the light-emitting surface 121u is enlarged. In one embodiment, the light-emitting angle A2 of the second light beam L2 is greater than +/- 90 degrees. With respect to the outline of the light-emitting surface 121u, the slope of the light-emitting surface 121u gradually decreases from the center line C1 toward the center line C1, and the light-emitting angle of the light refracted from the light-emitting surface 121u can be enlarged. Further, the light-emitting surface 121u may be constructed by a curved surface, a plane, or a combination thereof. The embodiment of the present invention does not limit the contour of the light surface 121u as long as the light extraction angle of the refracted ray can be expanded.

Fig. 3 is a view showing the field pattern of the second light beam L2 of Fig. 1B. It can be seen from the figure that the angle A2 of the maximum intensity of the field shape of the second light beam L2 with respect to the optical axis is greater than +/- 90 degrees, that is, the light angle of the second light beam L2 is greater than 180 degrees.

Fig. 4 is a cross-sectional view taken along line 4-4' in Fig. 1A. The reflection sheet 130 has a concave portion 130r, and the light-emitting element 110 is located inside the concave portion 130r. The recess 130r includes a reflective bottom surface 130b and a first reflective side surface 130s1, wherein the first reflective side surface 130s1 extends obliquely outward from the reflective bottom surface 130b. The second light beam L2 is emitted from the optical lens 120 and is incident on the reflective bottom surface of the reflective sheet 130. 130b is then reflected from the reflective bottom surface 130b to the first reflective side surface 130s1 of the reflective sheet 130, and then reflected from the first reflective side surface 130s1 to the light guide plate (not shown). Since the light exit angle A2 of the second light beam L2 is greater than +/- 90 degrees, the second light beam L2 is first incident on the reflective bottom surface 130b of the reflective sheet 130, and then reflected to the first reflective side surface 130s1, so that the first light reflection can be performed. The angle A5 of the second light beam L2 reflected by the side surface 130s1 and the center line C1 is relatively small (compared to the light exit angle A2 of the second light beam L2 is equal to or less than +/- 90 degrees); thus, the first reflection The second light beam L2 reflected by the side surface 130s1 can assist in supplementing the insufficient light intensity of the dark band area DA to eliminate the partial dark band area DA.

Since the second light beam L2 reflected from the first reflective side surface 130s1 can assist in supplementing the insufficient light intensity of the dark band area DA, the optical lens 120 needs to supplement the dark band area DA to have a reduced range of light intensity. Further, since the light exit angle A2 of the second light beam L2 is greater than +/- 90 degrees, the second light beam L2 reflected from the first reflective side surface 130s1 provides a light intensity to a portion of the dark band area DA, thereby making the first B-picture The range of the dark band area DA is reduced; thus, the range of the complementary dark band area DA of the first light beam L1 is reduced, so that the light exit angle A1 of the first light beam L1 can be designed to be small.

In addition, in the embodiment, the angle A6 between the first reflective side surface 130s1 and the bottom surface 130b is between 90 degrees and 180 degrees, so that the light exiting the light from above the light-emitting device 100 is wider (closer than the angle A6). 45 degrees or less than 90 degrees).

Fig. 5 is a cross-sectional view showing a reflection sheet according to another embodiment of the present invention. The reflection sheet 130 of the present embodiment includes a first reflection side surface 130s1 and a second reflection side surface 130s2. The first reflection side surface 130s1 extends obliquely outward from the reflection bottom surface 130b, and the second reflection side surface 130s2 extends obliquely outward from the first reflection side surface 130s1. First reflective side surface 130s1 and reflective bottom surface 130b An angle A7 is sandwiched between the second reflective side surface 130s2 and the reflective bottom surface 130b, wherein the angle A7 is different from the angle A8. In one embodiment, the angle A7 between the first reflective side surface 130s1 and the reflective bottom surface 130b is between 90 degrees and 170 degrees, and the angle A8 between the second reflective side surface 130s2 and the reflective bottom surface 130b is between 100 degrees and 180 degrees. Between the degrees, the light L emitted from the optical lens 120 is reflected by the first reflecting side 130s1 and the reflecting bottom surface 130b multiple times to enhance the uniformity of light emitted from the reflecting sheet 130.

FIG. 6 is a top plan view of a light emitting device according to another embodiment of the present invention. The light emitting device 200 includes a light emitting element 110 (not shown), an optical lens 120, a reflective sheet 130, and at least one reflective spacer 240. Since the reflective spacer 240 has a light reflecting property, the light emitted from the light emitting element 110 can be reflected. The reflective spacer 240 is located between at least two optical lenses 120. Compared with the design of FIG. 1A, the reflective spacer 240 of the present embodiment occupies the position of the at least one optical lens 120 and the light-emitting element 110 of FIG. 1A, so that the amount of the optical lens 120 and the light-emitting element 110 can be reduced, thereby reducing the optical The cost of the lens 120 and the light-emitting element 110.

Figure 7 is a cross-sectional view showing a light emitting device in accordance with another embodiment of the present invention. The light emitting device 300 includes a light emitting element 110, an optical lens 320, and a reflective sheet 130. The optical lens 320 includes a lens body 121 and a concave portion 122. The concave portion 122 includes a total reflection surface 122s1 and an inner side surface 122s2, wherein the total reflection surface 122s1 and the inner side surface 122s2 intersect the first intersection point P1. Unlike the optical lens 120 described above, the inner side surface 122s2 of the present embodiment extends obliquely downward from the first intersection point P1 to the bottom surface 121b, and the inner side surface 122s2 is inclined with respect to the bottom surface 121b. Similarly, the first light beam L1 reflected from the total reflection surface 122s1 can supplement the insufficient light intensity of the dark band area DA by the design of the total reflection surface 122s1.

Figure 8 is a cross-sectional view showing a light emitting device in accordance with another embodiment of the present invention. The light emitting device 400 includes a light emitting element 110, an optical lens 420, and a reflective sheet 130. The optical lens 420 includes a lens body 121 and a concave portion 122. The lens body 121 includes a groove 121r, a bottom surface 121b, and a light-emitting surface 121u. The groove 121r includes a light incident side surface 121s1 and a light incident top surface 121s2, wherein the light incident side surface 121s1 extends from the bottom surface 121b toward the light exit surface 121u and in the direction toward the center line C1. In the present embodiment, the light incident side surface 121s1 is tangent to the light incident top surface 121s2, and the light incident side surface 121s1 and the light incident top surface 121s2 are smoothly connected.

Unlike the optical lenses 120 and 320 described above, the concave portion 122 of the present embodiment omits the inner side surface 122s2. Further, the lens body 121 has an outer boundary surface 122s1 extending outward from the bottom surface 121b and extending toward the light exit surface 121u to the outer boundary surface 122s3, so that the total reflection surface 122s1 becomes the other outer boundary surface of the optical lens 420. Similarly, the first light beam L1 reflected from the total reflection surface 122s1 can supplement the insufficient light intensity of the dark band area DA by the design of the total reflection surface 122s1.

In conclusion, the present invention has been disclosed in the above preferred embodiments, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

110‧‧‧Lighting elements

120‧‧‧ optical lens

121‧‧‧ lens body

121b‧‧‧ bottom

121r‧‧‧ Groove

121s1‧‧‧light side

121s2‧‧‧ into the top of the light

121s3‧‧‧Into the light plane

121u‧‧‧Glossy surface

Concave inside 121u1‧‧

121u2‧‧‧ curved surface

122‧‧‧ recess

122s1‧‧‧ total reflection surface

122s2‧‧‧ inside side

122s3‧‧‧ outer boundary surface

140‧‧‧ boards

A1, A2‧‧‧ light angle

A3, A4‧‧‧ angle

C1‧‧‧ center line

C2, C3‧‧‧ connection

DA‧‧‧Dark zone

L1‧‧‧first beam

L2‧‧‧second beam

P1‧‧‧ first intersection

P2‧‧‧ second intersection

P3‧‧‧ third intersection

S1, S2‧‧‧ curve

Claims (8)

An optical lens comprising: a first bottom surface; a light-emitting surface; and a total reflection surface extending outward from the first bottom surface and toward the light-emitting surface; wherein the total reflection surface is caused by the total reflection surface The reflected light has an exit angle of less than 150 degrees to supplement the insufficient light intensity of the dark strip region; wherein the optical lens further includes a center line and a light incident side surface, a light incident top surface and a concave portion, and the concave portion further includes a An inner side surface, the total reflection surface intersecting the inner side surface at a first intersection point, the light incident side surface intersecting the light entrance top surface at a second intersection point, the center line intersecting an extension of the first bottom surface at a first The intersection angle of the line connecting the third intersection point and the second intersection point with respect to the first bottom surface is greater than the angle between the line connecting the third intersection point and the first intersection point with respect to the first bottom surface. The optical lens of claim 1, further comprising: a lens body having a groove, the first bottom surface and the light exiting surface, the groove extending from the first bottom surface toward the light exiting surface; wherein The recess extends from the first bottom surface of the lens body toward the light exiting surface and includes the total reflection surface. The optical lens of claim 1, wherein the lens body has a center line, and the optical lens further comprises: Upon entering the light plane, the center line passes through the light entrance plane. The optical lens of claim 1, further comprising a groove, the groove comprising a light-incident top surface and a light-incident side surface extending perpendicularly from the light-incident top surface to the first a bottom surface. The optical lens of claim 1, further comprising a groove and a center line, the groove comprising a light-incident top surface and a light-incident side surface, the light-incident side surface being away from the light-incident top surface The direction of the centerline extends to the first bottom surface. A light-emitting device comprising: a circuit board; an optical lens according to any one of claims 1 to 5, disposed on the circuit board; and a light-emitting element disposed in the optical lens. The illuminating device of claim 6, further comprising: a reflective sheet disposed on the circuit board and having a second bottom surface, a first reflective side surface and a second reflective side surface, the first reflection The angle between the side surface and the second bottom surface is different from the angle between the second reflection side and the second bottom surface. The illuminating device of claim 6, further comprising: a plurality of the optical lenses; a plurality of the light-emitting elements disposed in the corresponding optical lens; and a reflective spacer separating the optical lenses and the light-emitting elements.