JP5682326B2 - light source - Google Patents

Description

  The present invention relates to a light source, and more particularly, to a light source using polyhedral optical glass.

  Conventionally, in order to reduce the size and increase the output of a light source using polyhedral optical glass, inventions have been proposed in which a plurality of LEDs are arranged on the bottom and side surfaces of the optical glass (see Patent Documents 1 and 2).

JP 2007-329053 A Special table 2008-536266 gazette

  However, in the above-described conventional light source, light that travels in a direction perpendicular to the opposite side surface is incident on the light emitting device attached to the side surface of the optical glass and is transmitted to the outside of the optical glass. There was a problem of hindering the improvement of the output of the light source.

  Accordingly, an object of the present invention is to provide a light source in which light traveling in a direction perpendicular to the opposing side surfaces is not transmitted to the outside of the optical glass.

  According to the present invention, the above problem is solved by the following means.

The present invention is a light source in which a plurality of light emitting devices are attached to a side surface of a polyhedral optical glass, wherein the optical glass has a plurality of concave portions formed on a side surface, and the light emitting device is attached to the concave portion, The concave portion includes a first concave portion and a second surface that totally reflects light emitted from a light emitting device attached to the first concave portion and traveling in a direction perpendicular to the side surface on which the first concave portion is formed. And the second recess is emitted from a light emitting device attached to the first recess on a side surface opposite to the side surface on which the first recess is formed, and the first recess is formed. The light source is characterized in that the light traveling in a direction perpendicular to the side surface and the side surface facing the side surface on which the first recess is formed intersect at a position .

  Moreover, this invention is said light source characterized by the said recessed part being a substantially cone shape.

  Further, the present invention is characterized in that the concave portion is formed such that the area of the surface facing the light exit surface side of the optical glass is larger than the area of the surface facing the bottom surface side of the optical glass. The above light source.

  Moreover, this invention is said light source characterized by the said recessed part being provided in each side surface which the said optical glass opposes, respectively.

  Moreover, this invention is said light source characterized by the said light-emitting device being attached to the side and bottom face of the said optical glass.

  Moreover, this invention is said light source characterized by the above-mentioned. The reflection material is attached to the area | region except the area | region in which the said recessed part was formed in the side surface of the said optical glass.

  Further, the present invention is characterized in that a cover lens having substantially the same shape as the concave portion is attached to the light emitting device, and the light emitting device is attached to the concave portion by fitting the cover lens into the concave portion. The light source.

  According to the present invention, it is possible to provide a light source that prevents light traveling in a direction perpendicular to the opposing side surfaces from being transmitted to the outside of the optical glass.

It is a schematic perspective view of the light source which concerns on embodiment of this invention. It is a figure explaining the schematic structure of the light source which concerns on embodiment of this invention. It is the schematic at the time of forming various recessed parts in optical glass and seeing the formed recessed part from the inside of optical glass. It is a partial schematic sectional drawing of the light source which concerns on Example 1 of this invention. 6 is a partial schematic cross-sectional view of a light source according to Comparative Example 1. FIG.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated, referring attached drawing.

[Light Source According to Embodiment of the Present Invention]
FIG. 1 is a schematic perspective view of a light source according to an embodiment of the present invention.

  As shown in FIG. 1, a light source 1 according to an embodiment of the present invention is a light source in which a plurality of light emitting devices 20 are attached to a side surface of a polyhedral optical glass 10.

  In the light source 1 according to the embodiment of the present invention, light emitted from the plurality of light emitting devices 20 is multiple-reflected inside the optical glass 10, integrated, and emitted from the emission surface of the optical glass 10.

  The optical glass 10 is a polyhedron, and in the embodiment of the present invention, the optical glass 10 is composed of a hexahedron having an emission surface 11, a bottom surface 12, and four side surfaces (upper side surface 13, lower side surface 14, right side surface 15, left side surface 16). (The emission surface 11, the lower side surface 14, and the left side surface 16 do not appear in FIG. 1). In addition, the shape of the optical glass 10 can be comprised in various shapes besides a hexahedron.

  The plurality of light emitting devices 20 are attached to the side surfaces 13 to 16 of the optical glass 10. In the light source 1 according to the embodiment of the present invention, the bottom surface 12 of the optical glass 10 is added to the side surfaces 13 to 16 of the optical glass 10. A plurality of light emitting devices 20 are also attached to improve the output of the light source 1.

  2A and 2B are diagrams illustrating a schematic configuration of a light source according to an embodiment of the present invention, in which FIG. 2A is a partial schematic cross-sectional view of the light source (part of the AA cross section in FIG. 1), and FIG. Partial schematic sectional drawing of optical glass, (c) is a schematic sectional drawing of a light-emitting device.

  In the following description, the upper side surface 13 and the lower side surface 14 of the optical glass 10 will be mainly described. However, the right side surface 15 and the left side surface 16 can be considered in the same manner as the upper side surface 13 and the lower side surface 14.

(Optical glass)
The upper side surface 13 and the lower side surface 14 of the optical glass 10 are tapered so as to move away from the bottom surface 12 toward the emission surface 11.

  A plurality of recesses 30 are formed on the upper side surface 13, the lower side surface 14, and the bottom surface 12 of the optical glass 10. For example, the recess 30 is formed by cutting the optical glass 10. Here, the bottom surface 12 of the optical glass 10 is also formed with the recess 30, but the recess 30 may not be formed on the bottom surface 12.

  The recess 30 formed in the upper side surface 13 and the lower side surface 14 of the optical glass 10 has a surface that totally reflects light traveling in a direction perpendicular to the opposing side surfaces. The “opposite side surface” refers to a side surface facing the side surface on which the recess 30 is formed. In the embodiment of the present invention, the side surface facing the upper side surface 13 (lower side surface 14) is the lower side surface 14 (upper side surface). 13), and the side surface facing the right side surface 15 (left side surface 16) is the left side surface 16 (right side surface 15).

  Although the light emitted from the light emitting device 20 on the opposite side surface may be slightly changed in the traveling direction depending on the shape of the opposite side surface, the refractive index of the optical glass 10 is a substance outside the optical glass 10 (for example, Since it is higher than the refractive index of air), it generally proceeds in a “perpendicular direction to the opposite side surfaces”.

  For this reason, when the light emitting devices 20 are respectively attached to the opposing side surfaces (“upper side surface 13 and lower side surface 14” and / or “right side surface 15 and left side surface 16”) of the optical glass, On the other hand, the light emitted from the light emitting device 20 on the opposite side surface, that is, the light traveling in the “perpendicular direction to the opposite side surface” becomes easy to enter while maintaining strong energy, and to the outside of the optical glass 10. It becomes easy to penetrate.

  However, according to the light source 1 according to the embodiment of the present invention, the light traveling in the “direction perpendicular to the opposite side surface” is totally reflected by the surface of the recess 30 and is not transmitted to the outside of the optical glass 10. To be done.

  In addition, it is preferable that the recessed part 30 is a substantially cone shape (especially pyramid shape). In this way, a surface that totally reflects light traveling in the “direction perpendicular to the opposite side surface” can be easily formed in the recess 30.

(Light emitting device)
The light emitting device 20 is attached to the recess 30.

  As the light emitting device 20, for example, as shown in FIG. 2, an LED chip 21 sealed with a resin or the like is attached to a mounting base 22. The mounting base 22 is attached to the side surface of the optical glass 10 with an adhesive (not shown) or the like so that the LED chip 21 is positioned inside the recess 30.

  A cover lens 23 is preferably attached to the light emitting device 20. In this way, the confidentiality of the LED chip 21 can be improved.

  In addition, it is particularly preferable that the cover lens 23 has substantially the same shape as the recess 30. If it does in this way, the cover lens 23 can be fitted in the recessed part 30, and the light-emitting device 20 can be attached to the recessed part 30, and the light-emitting device 20 can be easily arrange | positioned in the recessed part 30 now.

  As described above, according to the light source 1 according to the embodiment of the present invention, the concave portions 30 described above are formed on the four side surfaces 13 to 16 of the optical glass 10, so that “perpendicular to the opposite side surfaces”. The light traveling in the “direction” is totally reflected by the recess 30.

  For this reason, according to the light source 1 according to the embodiment of the present invention, it is possible to prevent light traveling in the “perpendicular direction to the opposite side surface” from being transmitted to the outside of the optical glass 10. Can be improved.

  In the embodiment of the present invention, the recesses 30 are formed on the two opposing side surfaces (“upper side surface 13 and lower side surface 14”, “right side surface 15 and left side surface 16”), and the light emitting device 20 is attached thereto. However, the recess 30 and the light emitting device 20 may be provided on a pair of opposing side surfaces.

[Reflective material]
On the side surfaces 13 to 16 and the bottom surface 12 of the optical glass 10, it is preferable that a reflecting material (not shown) such as a mirror is attached to a region excluding the region where the recess 30 is formed. In this way, in the region excluding the region where the recess 30 is formed, that is, in the region where the reflecting material (not shown) is attached, the light is optical regardless of the incident angle. Transmission to the outside of the glass 10 can be prevented, and the output of the light source 1 can be further improved.

[Mirror tunnel]
If the optical glass 10 is covered with a mirror tunnel (not shown), the light transmitted through the optical glass 10 can be reflected, so that the output of the light source 1 can be further improved.

[Recess direction]
FIG. 3 is a schematic view when various concave portions are formed in the optical glass, and the formed concave portions are viewed from the inside of the optical glass, (a) is a schematic view when the concave portions are viewed from the inside of the optical glass, (B) is an enlarged view of the recess 42, (c) is an enlarged view of the recess 44, (d) is an enlarged view of the recess 46, and (e) is an enlarged view of the recess 48.

  FIG. 3A is a view in which, for example, the optical glass 10 is cut along a plane perpendicular to the AA cross section in FIG. 1 and various recesses formed on the lower side surface 14 are seen from the cut surface. Equivalent to. Further, in FIG. 3A, the illustration of the recesses and the light emitting device in the bottom surface 12, the right side surface 15, and the left side surface 16 is omitted in order to avoid the drawing from becoming complicated.

  As shown in FIG. 3, concave portions 41 to 48 having various shapes can be formed in the optical glass 10, but the concave portion has a surface area facing the emission surface 11 side of the optical glass 10. It is particularly preferable that it is formed so as to be larger than the area of the surface facing the bottom surface 12 side.

  The surface facing the emission surface 11 side of the optical glass 10 means that the normal glass (broken line in FIG. 3) of the surface is parallel to the bottom surface 12 of the optical glass 10 (dashed line in FIG. 3). The surface facing the bottom surface 12 side of the optical glass 10 is a line in which the normal of the surface (broken line in FIG. 3) is parallel to the bottom surface 12 of the optical glass 10 ( It means that it is inclined toward the bottom surface 11 side of the optical glass 10 with respect to the one-dot chain line in FIG.

  In this case, light traveling in the “perpendicular direction to the opposite side surface” is reflected by the concave portion toward the emission surface 11 side of the optical glass 10 rather than the bottom surface 12 side of the optical glass 10. In the case where more light emitting devices 20 are attached to the bottom surface 12 side than the emission surface 11 side, the ratio of light incident on the light emitting device 20 can be reduced. For this reason, it becomes possible to further prevent the light from being transmitted to the outside of the optical glass 10 through the light emitting device 20, and the output of the light source 1 can be further improved.

More specifically, the concave portion 42 and the concave portion 44 are concave portions having the same shape (regular triangular pyramid shape).
The surfaces 42a and 42b of the recess 42 are surfaces facing the emission surface 11 side of the optical glass 10,
The surface 42c of the recess 42 is a surface facing the bottom surface 12 side of the optical glass 10,
The surface 44a of the recess 44 is a surface facing the emission surface 11 side of the optical glass 10,
The surfaces 44 b and 44 c of the recess 44 are surfaces facing the bottom surface 12 side of the optical glass 10.
Therefore, the concave portion 42 and the concave portion 44 are preferable because the concave portion 42 has a larger area of the surface facing the emission surface 11 side of the optical glass 10 than the concave portion 44.

Moreover, although the recessed part 46 and the recessed part 48 are recessed parts of the same shape (regular pentagonal pyramid shape),
The surfaces 46a, 46b, 46c of the recess 46 are surfaces facing the emission surface 11 side of the optical glass 10,
The surfaces 46d and 46e of the recess 46 are surfaces facing the bottom surface 12 side of the optical glass 10,
The surfaces 48a and 48b of the recess 48 are surfaces facing the emission surface 11 side of the optical glass 10,
The surfaces 48 c, 48 d, and 48 e of the recess 48 are surfaces facing the bottom surface 12 side of the optical glass 10.
Therefore, the concave portion 46 and the concave portion 48 are preferable because the concave portion 46 has a larger surface area facing the emission surface 11 side of the optical glass 10 than the concave portion 48.

  Next, as Example 1 of the present invention, an example of a method for confirming whether or not the concave portion has a surface that totally reflects will be described.

  As described above, in the light source 1 according to the embodiment of the present invention, the recess formed on the side surface of the optical glass has a surface that totally reflects light traveling in the “direction perpendicular to the opposite side surface”. ing.

  More specifically, the recess has a surface that is inclined so that light traveling in the “perpendicular direction to the opposite side surface” is incident at an angle greater than the critical angle.

  Whether or not the surface of the concave portion is inclined in this way can be confirmed by various methods. However, in Example 1, two substantially triangular pyramid-like shapes are used to facilitate understanding of the present invention. The concave portions (first concave portion 51, second concave portion 52) are taken as an example, and it is determined whether or not these concave portions (first concave portion 51, second concave portion 52) have the above-mentioned surface. The case where it confirms with the cross section (surface equivalent to the AA cross section of FIG. 1) perpendicular | vertical with respect to the output surface 11 and the bottom face 12 is demonstrated.

  FIG. 4 is a partial schematic cross-sectional view of the light source according to the first embodiment of the present invention.

  As shown in FIG. 4, the first recess 51 has a surface 51 a facing the emission surface 11 side of the optical glass 10 and a surface 51 b facing the bottom surface 12 side of the optical glass 10, and the second recess 52 is optical The glass 10 has a surface 52 a facing the emission surface 11 side and a surface 52 b facing the bottom surface 12 side of the optical glass 10.

  However, the light traveling in the direction perpendicular to the upper side surface 13 is totally reflected by the surface 51 a facing the emission surface 11 side of the optical glass 10 at the first concave portion 51, and the bottom surface of the optical glass 10 at the second concave portion 52. It is totally reflected by the surface 52b facing the 12 side.

  Therefore, the surface 51a facing the emission surface 11 side of the optical glass 10 is examined for the first recess 51, and the surface 52b facing the bottom surface 12 side of the optical glass 10 is examined for the second recess 52.

  In order to avoid complication of the drawing, in FIG. 4, the illustration of the concave portions formed on the upper side surface 13 and the bottom surface 12 and the light emitting device attached to the concave portions is omitted. Moreover, since the 1st recessed part 51 and the 2nd recessed part 52 are substantially triangular pyramid shapes, although the surface which is not illustrated in FIG. 4 is also provided, description about these surfaces is abbreviate | omitted.

As shown in FIG. 4, in the first recess 51, surface 51a facing the emission surface 11 side of the optical glass 10 is inclined at an inclination angle epsilon ₁ against the lower surface 14 of the optical glass 10. In the second recess 52, the surface 52 b facing the bottom surface 12 side of the optical glass 10 is inclined at an inclination angle ε ₂ with respect to the lower surface 14 of the optical glass 10.

Here, it is assumed that light traveling in a direction perpendicular to the upper side surface 13 is incident at an incident angle θ ₁ on the surface 51 a facing the emission surface 11 side of the optical glass 10 included in the first recess 51.

Further, light traveling in a direction perpendicular to the upper side surface 13 is incident at an incident angle θ ₂ on the surface 52b facing the bottom surface 12 side of the optical glass 10 included in the second recess 52.

  The taper angle of the upper side surface 13 of the optical glass 10 is α, and the taper angle of the lower side surface 14 of the optical glass is β.

In this case, the inclination angle ε ₁ and the inclination angle ε ₂ can be expressed by the following equations.
_{· Θ 1 = 180-ε 1} + (α + β) ··· Formula 1
・ Θ ₂ = 180−ε ₂ + (α + β) Equation 2

If the incident angle θ ₁ is larger than the critical angle θ _{c1 of the} surface 51 a facing the exit surface 11 side of the optical glass 10 included in the first recess 51 (see the following formula), it is perpendicular to the upper side surface 13. The traveling light is totally reflected by the surface 51 a facing the emission surface 11 side of the optical glass 10 of the first recess 51.
・ Θ ₁ > θ _c1 Formula 3

In addition, if the incident angle θ ₂ is larger than the critical angle θ _c2 of the surface 52 _b facing the bottom surface 12 side of the optical glass 10 included in the second recess 52 (see the following formula), the direction perpendicular to the upper side surface 13. The light traveling to is totally reflected by the surface 52b facing the bottom surface 12 of the optical glass 10 included in the second recess 52.
・ Θ ₂ > θ _c2 Formula 4

From Equations 1 to 4, the following equation is derived.
180-ε ₁ + (α + β)> θ _c1 Formula 5
180-ε ₂ + (α + β)> θ _c2 Formula 6

Therefore, for the first concave portion 51 and the second concave portion 52 taken as an example in the first embodiment of the present invention, whether the inclination angle ε ₁ and the inclination angle ε ₂ satisfy Equations 5 and 6 respectively. By determining, it is possible to confirm whether or not it has a surface that totally reflects light traveling in the “direction perpendicular to the opposite side surface”.

The critical angle θ _c1 and the critical angle θ _c2 are obtained by the following equations.
Sin (θ _c1 ) = n _{substance inside} n _recess / n _{optical glass}
Sin (θ _c2 ) = _{substance inside} n- _concave / n _{optical glass:} Formula 8

Here, _{the substance inside the} n _recess is the refractive index of the substance inside the first recesses 51 and 52 (eg, air when there is no cover lens, cover lens when there is a cover lens), n _{The optical glass} has a refractive index of the optical glass 10.

[Comparative Example 1]
FIG. 5 is a partial schematic cross-sectional view of a light source according to Comparative Example 1.

  As shown in FIG. 5, in the light source according to Comparative Example 1, no recess is formed on the upper side surface 13 and the lower side surface 14 of the optical glass 10. For this reason, in the light source according to Comparative Example 1, a part of the light traveling in the direction perpendicular to the upper side surface 13 is not totally reflected by the lower side surface 14 of the optical glass 10 but is transmitted to the outside of the optical glass 10. End up. In FIG. 5, illustration of the light emitting device attached to the upper side surface 13 and the bottom surface 12 is omitted.

  As mentioned above, although embodiment and the Example of this invention were described, these description is related to an example of this invention, and this invention is not limited at all by these description.

DESCRIPTION OF SYMBOLS 1 Light source 10 Optical glass 11 Output surface 12 Bottom surface 13 Upper side surface 14 Lower side surface 15 Right side surface 16 Left side surface 20 Light-emitting device 21 LED chip 22 Mounting base 23 Cover lens 30, 41-48 Recessed part 42a-42c Surface 44a- which the recessed part 42 has 44c Surfaces 46a to 46e of the recess 44 Surfaces 48a to 48e of the recess 46 Surface 51 of the recess 48 First recess 52 Second recesses 51a and 51b Surfaces 52a and 52b of the first recess 51 Second recess 52 has surface

Claims (7)

A light source in which a plurality of light emitting devices are attached to a side surface of a polyhedral optical glass,
The optical glass has a plurality of concave portions formed on a side surface,
The light emitting device is attached to the recess,
The recess includes a first recess and a surface that totally reflects light emitted from a light emitting device attached to the first recess and traveling in a direction perpendicular to the side surface on which the first recess is formed. 2 recesses,
The second recess is a direction perpendicular to the side surface on which the first recess is formed by emitting light from the light emitting device attached to the first recess on the side facing the side on which the first recess is formed. And a side surface facing the side surface on which the first recess is formed intersects with the light source.   The light source according to claim 1, wherein the concave portion has a substantially cone shape.   The said recessed part is formed so that the area of the surface which faces the output surface side of the said optical glass may become larger than the area of the surface which faces the bottom face side of the said optical glass. Item 3. The light source according to Item 2.   The light source according to any one of claims 1 to 3, wherein the concave portion is provided on each of opposite side surfaces of the optical glass.   The light source according to claim 1, wherein the light emitting device is attached to a side surface and a bottom surface of the optical glass.   The light source according to any one of claims 1 to 5, wherein a side surface of the optical glass has a reflective material attached to a region excluding a region where the concave portion is formed.   The cover lens having substantially the same shape as the concave portion is attached to the light emitting device, and the light emitting device is attached to the concave portion by fitting the cover lens into the concave portion. The light source according to any one of the above.

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