JP2014167851A - Optical lens and light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the possibility of generation of illuminance unevenness on an irradiated surface in an edge-light type lighting system.SOLUTION: A lens 30 has a cylindrical shape with a curvature in an X axis direction and no curvature in a Y axis direction perpendicular to the X axis direction, and includes: a first reflection surface 321 for reflecting light emitted from a light emitting diode 25 to one side in the X axis direction; a second reflection surface 322 for reflecting the light emitted from the light emitting diode 25 to the other side in the X axis direction; a first incident surface 311 on which the light reflected by the first reflection surface 321 is incident; a second incident surface 312 on which the light reflected by the second reflection surface 322 is incident; an emission surface 315 for emitting light; a third reflection surface for reflecting the light incident from the first incident surface 311 toward the emission surface; and a fourth reflection surface for reflecting the light incident from the second incident surface 312 toward the emission surface.

Description

  The present invention relates to an optical lens and a light-emitting device including the optical lens.

  There is known an illumination device such as an internally illuminated double-sided signboard that irradiates light emitted from a light emitting device provided therein from the inside of the signboard. In such an illumination device, a structure called a so-called edge light system is known. This edge light method is advantageous in terms of cost because it has a simple structure compared to the so-called direct method, and also has low power consumption due to the small number of light emitting devices, and can further reduce the thickness of the lighting device. There is a merit in this point (see, for example, Patent Document 1).

JP 2013-004233 A

  However, since the above-described edge light type illumination device is configured to irradiate light from the side surface of the irradiated surface, the arrangement and number of light emitting devices are limited. Therefore, when the light distribution is widened, the vicinity of the light emitting device becomes too bright, resulting in uneven illuminance. On the other hand, if the light distribution is narrowed to irradiate light over a wider range, the spread of light is conversely insufficient, and uneven illuminance in the vicinity of the light-emitting device becomes conspicuous. In other words, the edge light type illumination device has a problem that unevenness in illumination tends to occur on the irradiated surface due to its structure.

  The present invention has been made in view of such circumstances, and an object of the present invention is to reduce the possibility of uneven illuminance on an irradiated surface in an edge light type illumination device.

<First Aspect of the Present Invention>
A first aspect of the present invention is a cylindrical optical lens having a curvature in the X-axis direction and no curvature in the Y-axis direction orthogonal to the X-axis direction, and the light emitted from the light source is emitted in the X-axis direction. A first reflecting surface portion that reflects to one side of the light source, a second reflecting surface portion that reflects light emitted from the light source to the other side in the X-axis direction, and a first incident surface portion on which light reflected by the first reflecting surface portion enters. A second incident surface portion on which light reflected by the second reflective surface portion is incident, an output surface portion that emits light, and a third reflective surface portion that reflects light incident from the first incident surface portion to the output surface portion, An optical lens comprising: a fourth reflecting surface portion that reflects light incident from the second incident surface portion to the emitting surface portion.

  First, by forming a cylindrical shape having a curvature in the X-axis direction and no curvature in the Y-axis direction perpendicular to the X-axis direction, the light emitted from the light source is not condensed in the Y-axis direction but only in the X-axis direction. It can be condensed. As a result, in an edge light type illumination device in which irradiated surfaces are arranged in parallel to the Y axis on both sides in the X-axis direction with respect to the optical lens, the irradiated surface is irradiated with light efficiently and irradiated. Irradiance unevenness on the surface can be reduced.

  Furthermore, in the course of earnest research, the applicant has gained knowledge that light that directly enters the optical lens from the light source and passes through the exit surface as it is is a cause of uneven illumination on the irradiated surface. It was. In the optical lens according to the present invention made based on such knowledge, light emitted from the light source is reflected by the first reflecting surface portion to one side in the X-axis direction. The light emitted from the light source is reflected to the other side in the X-axis direction by the second reflecting surface portion. The light reflected by the first reflecting surface portion enters the optical lens from the first incident surface portion, and is further reflected by the third reflecting surface portion in the optical lens and is emitted from the emitting surface portion. Similarly, the light reflected by the second reflecting surface portion is incident on the optical lens from the second incident surface portion, is further reflected by the fourth reflecting surface portion in the optical lens, and is emitted from the emitting surface portion.

  That is, in the optical lens according to the present invention, at least a part of the light emitted from the light source is incident after being reflected in the X-axis direction, and further reflected internally and emitted from the emission surface portion. As a result, it is possible to reduce the light that is directly incident on the optical lens from the light source and passes through to the exit surface as it is, so that it is possible to reduce illuminance unevenness on the irradiated surface.

  Thereby, according to the 1st aspect of this invention, the effect that the possibility that the illumination intensity nonuniformity of a to-be-irradiated surface arises in an edge light type illuminating device can be reduced is acquired.

<Second Aspect of the Present Invention>
According to a second aspect of the present invention, in the first aspect of the present invention described above, a lens body formed of a light-transmitting material, and a reflective member that forms the first reflective surface portion and the second reflective surface portion. An optical lens characterized by comprising:
According to such a feature, it is possible to easily mass-produce optical lenses on which the first reflection surface portion and the second reflection surface portion having extremely high reflectivity are formed. In addition, since it is possible to easily adjust the arrangement of the first reflecting surface portion and the second reflecting surface portion with respect to the first incident surface portion and the second incident surface portion, it is possible to further reduce the possibility of uneven illumination on the irradiated surface. Can do.

<Third Aspect of the Present Invention>
According to a third aspect of the present invention, in the first aspect or the second aspect of the present invention described above, the emission surface portion has a shape in which emitted light diffuses in the Y-axis direction. It is an optical lens.
According to such a feature, it is possible to further reduce the possibility of uneven illuminance on the irradiated surface in the edge light type illumination device by further diffusing the light emitted from the emission surface portion in the Y-axis direction.

<Fourth aspect of the present invention>
According to a fourth aspect of the present invention, in the third aspect of the present invention described above, the output surface portion includes a plurality of ridges having a shape in which emitted light is refracted in the Y-axis direction and adjacent to the Y-axis direction. An optical lens characterized by being formed.
According to such a feature, it is possible to easily mass-produce an optical lens including an emission surface portion in a shape in which emitted light is diffused in the Y-axis direction.

<Fifth aspect of the present invention>
According to a fifth aspect of the present invention, there is provided the optical lens according to any one of the first to fourth aspects of the present invention described above, and a light source disposed to face the first reflective surface portion and the second reflective surface portion. And a light emitting device.
According to the fifth aspect of the present invention, in the edge light type illumination device using this light emitting device, the operational effects of any of the first to fourth aspects of the present invention described above can be obtained.

<Sixth aspect of the present invention>
According to a sixth aspect of the present invention, in the fifth aspect of the present invention described above, a box-shaped upper cover formed of a light-transmitting material and having an open bottom surface covers the opening at the bottom surface of the upper cover. A circuit board that is mounted in an internal space formed by the upper cover and the lower cover, on which the light-emitting diode serving as the light source is mounted, and the optical lens includes the upper cover and The light emitting device is formed integrally.

  According to such a feature, since the number of parts of the light emitting device can be reduced by forming the optical lens integrally with the upper cover, the light emitting device according to the present invention can be mass-produced at a lower cost. Can do. Further, since the optical lens is formed integrally with the upper cover, it is possible to reduce the possibility that the position of the optical lens with respect to the light source is shifted from an appropriate position due to, for example, vibration or impact.

<Seventh aspect of the present invention>
A seventh aspect of the present invention is the light emitting device according to the fifth aspect or the sixth aspect of the present invention, wherein a plurality of the light sources are arranged along the Y-axis direction. is there.
According to such a feature, in the edge light type illumination device, it is possible to further improve the illuminance while reducing the possibility of uneven illumination on the irradiated surface.

  ADVANTAGE OF THE INVENTION According to this invention, the possibility that the illuminance nonuniformity of a to-be-irradiated surface may arise in an edge light type illuminating device can be reduced.

The front view of an internally illuminated double-sided signboard. The principal part sectional side view of an internal illumination type double-sided signboard. The external appearance perspective view of a light-emitting device. The top view of a light-emitting device. FIG. 5 is a cross-sectional view of a light emitting device illustrating a cross section taken along line II in FIG. 4. The perspective view of a lens. The front view of a lens. Sectional drawing of the light-emitting device which illustrated the II-II cross section of FIG. The principal part top view of the modification of a light-emitting device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In addition, this invention is not specifically limited to the Example demonstrated below, It cannot be overemphasized that a various deformation | transformation is possible within the range of the invention described in the claim.

<Configuration of lighting device>
A configuration of an internally illuminated double-sided signboard 10 as an example of an edge light type illumination device will be described with reference to FIGS. 1 and 2.
FIG. 1 is a front view of an internally illuminated double-sided signboard 10. FIG. 2 is a cross-sectional side view of a main part of the internally illuminated double-sided signboard 10.

  The internally illuminated double-sided signboard 10 has a rectangular parallelepiped shape including a first signboard surface part 11, a second signboard surface part 12, a bottom part 13, an upper part 14, a right side part 15 and a left side part 16, and includes a plurality of light emitting devices 20 in an internal space. . The 1st signboard surface part 11 and the 2nd signboard surface part 12 are thin plate-shaped members formed with the material which has a light transmittance. The light emitting device 20 is a device that irradiates light emitted from the light emitting diodes from the inside to the first signboard surface portion 11 and the second signboard surface portion 12 (irradiated surface). The bottom portion 13 and the top portion 14 are formed of a material that does not have light transmittance. In order to reduce illuminance unevenness of the first signboard surface portion 11 and the second signboard surface portion 12, it is preferable that the inner peripheral surfaces of the bottom portion 13 and the upper portion 14 have a high light reflectance.

  Here, the direction orthogonal to the first signboard surface portion 11 and the second signboard surface portion 12 is the X-axis direction, and the direction parallel to the inner bottom surface 131 of the bottom portion 13 and orthogonal to the X-axis direction is the Y-axis direction, X-axis direction, and Y-axis direction. The direction orthogonal to is the Z-axis direction, and so on. The plurality of light emitting devices 20 are arranged and fixed on the inner bottom surface 131 of the bottom 13 side by side in the same direction in the Y-axis direction.

<Configuration of light emitting device>
The configuration of the light emitting device 20 will be described with reference to FIGS.
FIG. 3 is an external perspective view of the light emitting device 20. FIG. 4 is a plan view of the light emitting device 20. FIG. 5 is a cross-sectional view of the light-emitting device 20, and illustrates the II cross-section of FIG. 4.

  The light emitting device 20 according to the present invention includes an upper cover 21, a lower cover 22, four male screws 23, a circuit board 24, a light emitting diode 25, and a lens 30.

  The upper cover 21 is formed of a light-transmitting material such as a transparent resin material such as polymethyl methacrylate (PMMA), polycarbonate (PC), epoxy resin (EP), or a transparent resin material such as glass. A lens support part 211 and an attachment part 212 are included. The lens support portion 211 has a substantially box shape with an open bottom, and the lens 30 is integrally formed inside. The attachment portion 212 is formed so as to protrude outward from the periphery of the opening of the lens support portion 211, and includes two cable gripping portions 213 and four attachment holes 214. The cable gripping portions 213 are formed at both ends in the Y-axis direction, and are formed to grip a power cable (not shown) that supplies power to the light emitting diode 25. The four attachment holes 214 are respectively inserted with male screws 23 that are screwed into the female screw holes of the lower cover 22, and are provided to fix the upper cover 21 to the lower cover 22 with screws.

  The lower cover 22 is a member that covers the opening on the bottom surface of the upper cover 21, and is formed of a material that does not have light transmittance. The lower cover 22 includes two cable gripping portions 221 and two fixing portions 222. The two cable gripping portions 221 are respectively provided in portions corresponding to the cable gripping portion 213 of the upper cover 21, and are integrated with the cable gripping portion 213 of the upper cover 21 to supply power to the light emitting diode 25. Hold a cable (not shown). The two fixing portions 222 are provided so as to protrude on both sides in the Y-axis direction, and are through holes for fixing the light emitting device 20 to the inner bottom surface 131 of the bottom portion 13 of the internally illuminated double-sided signboard 10 with screws. 223 are respectively formed.

  The circuit board 24 is disposed in a sealed internal space constituted by the upper cover 21 and the lower cover 22, and is fixed to the upper surface recess 224 of the lower cover 22. On the circuit board 24, a light emitting diode 25 as a “light source” and electronic components constituting the peripheral circuit are mounted.

FIG. 6 is a perspective view of the lens 30. FIG. 7 is a front view of the lens 30.
The lens 30 as an “optical lens” has a single convex cylindrical shape having a curvature in the X-axis direction and no curvature in the Y-axis direction. Thereby, the light emitted from the light emitting diode 25 can be condensed only in the X-axis direction without being condensed in the Y-axis direction, so that the light is efficiently emitted to the first signboard surface portion 11 and the second signboard surface portion 12. Irradiation can be reduced to reduce the illuminance unevenness.

The lens 30 includes a lens body 31 and a reflecting member 32.
The lens body 31 is formed of a light-transmitting material like the upper cover 21, and is formed integrally with the lens support portion 211 of the upper cover 21. Since the lens 30 is formed integrally with the upper cover 21 as described above, the number of components of the light emitting device 20 can be reduced, and the light emitting device 20 can be mass-produced at a lower cost. Further, since the lens 30 is formed integrally with the upper cover 21, it is possible to reduce a possibility that the position of the lens 30 with respect to the light emitting diode 25 is shifted from an appropriate position due to vibration or impact, for example.

The lens body 31 includes a concave groove 33, a fitting convex portion 34, a first incident surface portion 311, a second incident surface portion 312, a third reflecting surface portion 313, a fourth reflecting surface portion 314, and an exit surface portion 315.
The concave groove 33 is formed along the Y-axis direction. The fitting convex portion 34 is a protrusion formed on the bottom surface of the concave groove 33 along the Y-axis direction. The first incident surface portion 311 is an inner surface on one side of the groove 33 in the X-axis direction, and is a flat surface parallel to the Y-axis direction. The second incident surface portion 312 is the inner surface on the other side in the X-axis direction of the groove 33 and is a flat surface parallel to the Y-axis direction. The third reflecting surface portion 313 is an outer peripheral surface on one side of the lens body 31 in the X-axis direction. The fourth reflecting surface portion 314 is an outer peripheral surface on the other side of the lens body 31 in the X-axis direction. The emission surface portion 315 is a flat surface on the upper side of the lens body 31 and is a surface portion orthogonal to the Z-axis direction, and constitutes an upper surface portion of the upper cover 21.

The reflecting member 32 is a member formed of a material that does not have optical transparency, and is preferably formed of a member that totally reflects light, such as a metal member whose surface is mirror-polished. The reflection member 32 includes a first reflection surface portion 321, a second reflection surface portion 322, and a fitting recess 323.
The first reflecting surface portion 321 is a slope that faces the first incident surface portion 311 of the lens body 31 with a certain angle. The second reflecting surface portion 322 is a slope that faces the second incident surface portion 312 of the lens body 31 with a certain angle. That is, the first reflecting surface portion 321 and the second reflecting surface portion 322 form a reflecting surface that is substantially V-shaped when viewed from the Y-axis direction. The fitting recess 323 is formed on the upper surface of the reflecting member 32 along the Y-axis direction. The reflecting member 32 is fixed to the lens main body 31 in a state where the fitting concave portion 323 is fitted to the fitting convex portion 34 of the lens main body 31.

  In addition, although the lens 30 of the structure which forms the 1st reflective surface part 321 and the 2nd reflective surface part 322 with the reflective member 32 of another member was demonstrated to the example, the said description is demonstrated with the single member by the resin material etc. which have light transmittance, for example. The lens 30 having the above-described configuration may be formed.

  The light emitting diode 25 is disposed at a position facing the first reflecting surface portion 321 and the second reflecting surface portion 322. The light emitting diode 25 is preferably arranged so that its optical axis coincides with the boundary line between the first reflecting surface portion 321 and the second reflecting surface portion 322.

  The first reflecting surface portion 321 reflects light emitted from the light emitting diode 25 to one side in the X-axis direction. More specifically, the first reflecting surface portion 321 reflects light emitted from the light emitting diode 25 to one side in the X-axis direction on one side in the X-axis direction from the center of the lens 30 in the X-axis direction. The light incident on the first reflecting surface portion 321 enters the first incident surface portion 311. The third reflecting surface portion 313 reflects the light incident from the first incident surface portion 311 to the emitting surface portion 315.

  The second reflecting surface portion 322 reflects the light emitted from the light emitting diode 25 to the other side in the X-axis direction. More specifically, the second reflecting surface portion 322 reflects light emitted from the light emitting diode 25 to the other side in the X-axis direction on the other side in the X-axis direction from the center of the lens 30 in the X-axis direction. The light incident on the second reflecting surface portion 322 is incident on the second incident surface portion 312. The fourth reflecting surface portion 314 reflects the light incident from the second incident surface portion 312 to the emitting surface portion 315.

  That is, the light emitted from the light emitting diode 25 is reflected to one side in the X-axis direction by the first reflecting surface portion 321 of the reflecting member 32 and reflected to the other side in the X-axis direction by the second reflecting surface portion 322 of the reflecting member 32. The light reflected by the first reflecting surface portion 321 enters the lens body 31 from the first incident surface portion 311, is reflected by the third reflecting surface portion 313, and exits from the emitting surface portion 315 (FIG. 7). Similarly, the light reflected by the second reflecting surface portion 322 enters the lens body 31 from the second incident surface portion 312, is reflected by the fourth reflecting surface portion 314, and is emitted from the emitting surface portion 315 (FIG. 7).

  As described above, in the lens 30 according to the present invention, at least a part of the light emitted from the light emitting diode 25 is incident after being reflected in the X-axis direction, and is further reflected inside and emitted from the emission surface portion 315. As a result, it is possible to reduce the light that directly enters the lens 30 from the light emitting diode 25 and passes through the exit surface portion 315 as it is, so that unevenness in illuminance on the first signboard surface portion 11 and the second signboard surface portion 12 can be reduced. .

  Further, the lens 30 according to the present invention has a configuration in which the first reflecting surface portion 321 and the second reflecting surface portion 322 are formed by the reflecting member 32 which is a separate member from the lens body 31 as in the above-described embodiment. preferable. Accordingly, the lens 30 formed with the first reflecting surface portion 321 and the second reflecting surface portion 322 having extremely high reflectivity can be easily mass-produced. In addition, since it is possible to easily adjust the arrangement of the first reflecting surface portion 321 and the second reflecting surface portion 322 with respect to the first incident surface portion 311 and the second incident surface portion 312, the first signboard surface portion 11 and the second signboard surface portion. The possibility that twelve illuminance unevenness may occur can be further reduced.

FIG. 8 is a cross-sectional view of the light-emitting device 20 and illustrates the II-II cross-section of FIG.
The emission surface portion 315 preferably has a shape in which emitted light diffuses in the Y-axis direction. More specifically, it is preferable that the exit surface portion 315 is formed with a plurality of ridges having a shape in which emitted light is refracted in the Y-axis direction, adjacent to each other in the Y-axis direction. For example, the output surface portion 315 of this embodiment is formed with a large number of ridges having a triangular cross-sectional shape viewed from the X-axis direction. By further diffusing the light emitted from the exit surface portion 315 in the Y-axis direction, it is possible to further reduce the possibility of uneven illumination on the first signboard surface portion 11 and the second signboard surface portion 12 in the internally illuminated double-sided signboard 10.

<Modification of light emitting device>
A modification of the light emitting device 20 according to the present invention will be described with reference to FIG.
FIG. 9 is a main part plan view of a modification of the light emitting device 20.

  In the modification of the light emitting device 20 illustrated in FIG. 9, the dimension in the Y axis direction is long, and the three light emitting diodes 25 are arranged in the Y axis direction at positions facing the first reflecting surface portion 321 and the second reflecting surface portion 322. The configuration is different from that of the light emitting device 20 described above in that the light emitting devices 20 are arranged at intervals along the direction. Since other configurations are the same as those of the light emitting device 20 described above, common portions are denoted by the same reference numerals and detailed description thereof is omitted.

  By arranging a plurality of light emitting diodes 25 along the Y-axis direction in this way, in the internally illuminated double-sided signboard 10, while reducing the possibility of uneven illumination on the first signboard surface part 11 and the second signboard surface part 12, further Illuminance can be improved.

DESCRIPTION OF SYMBOLS 10 Inner-illuminated double-sided signboard 20 Light-emitting device 21 Upper cover 22 Lower cover 23 Male screw 24 Circuit board 25 Light emitting diode 30 Lens 31 Lens main body 32 Reflective member 311 1st incident surface part 312 2nd incident surface part 313 3rd reflective surface part 314 4th Reflective surface portion 315 Output surface portion 321 First reflective surface portion 322 Second reflective surface portion

Claims (7)

A cylindrical optical lens having a curvature in the X-axis direction and no curvature in the Y-axis direction perpendicular to the X-axis direction,
A first reflecting surface portion that reflects light emitted from a light source to one side in the X-axis direction;
A second reflecting surface portion that reflects light emitted from the light source to the other side in the X-axis direction;
A first incident surface portion on which light reflected by the first reflective surface portion is incident;
A second incident surface portion on which light reflected by the second reflective surface portion is incident;
An exit surface that emits light;
A third reflecting surface portion that reflects the light incident from the first incident surface portion to the emitting surface portion;
An optical lens comprising: a fourth reflecting surface portion that reflects light incident from the second incident surface portion to the emitting surface portion.   The optical lens according to claim 1, comprising a lens body formed of a light-transmitting material, and a reflecting member that forms the first reflecting surface portion and the second reflecting surface portion. Optical lens.   3. The optical lens according to claim 1, wherein the emission surface portion has a shape in which emitted light diffuses in the Y-axis direction. 4.   4. The optical lens according to claim 3, wherein the exit surface portion is formed with a plurality of ridges adjacent to the Y-axis direction so that emitted light is refracted in the Y-axis direction. Optical lens. The optical lens according to any one of claims 1 to 4,
A light source disposed opposite to the first reflective surface portion and the second reflective surface portion. The light-emitting device according to claim 5, wherein the box-shaped upper cover is formed of a light-transmitting material and has an open bottom.
A lower cover that covers the opening on the bottom surface of the upper cover;
A light-emitting diode as a light source is mounted, and further includes a circuit board disposed in an internal space constituted by the upper cover and the lower cover,
The light-emitting device, wherein the optical lens is formed integrally with the upper cover.   The light-emitting device according to claim 5, wherein a plurality of the light sources are arranged along the Y-axis direction.

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