JP2018536286A - LED lens - Google Patents

Abstract

  The present invention relates to an LED lens that can uniformly diffuse light emitted from an LED. An LED lens according to an embodiment of the present invention is an LED lens for uniformly diffusing light emitted from an LED, an incident surface on which light emitted from the LED enters the lens, and the lens through the incident surface. An exit surface for emitting the light incident on the inside of the lens to the outside of the lens, and the exit surface has a first exit surface that forms a curved surface convex toward the LED on a vertical cross section, and the first exit surface. A second emission surface that is positioned around the surface and forms a curved surface that is convex on the opposite side of the LED, and an inflection point site that exists at a connection portion between the first emission surface and the second emission surface. Has a convex portion having a convex shape upward on a vertical cross section, and the convex portion has a circular band shape surrounding the inflection point existing in a circular shape around the optical axis of the LED on the plane. Can be formed.

Description

  The present invention relates to an LED lens that can uniformly diffuse light emitted from an LED.

  In general, LEDs (Light Emitting Diodes) have high light conversion efficiency, so they have relatively low power consumption, fast response speed, simple lighting circuits, and excellent safety. Widely used as a light source.

  However, when an LED is used as a light source, the light tends to diverge and concentrate in a narrow area. Therefore, in order to apply it to a lighting device, it is necessary to distribute the light uniformly over a wide area. is there.

  Patent Document 1 is a typical prior art relating to an LED lens that performs such a function.

  However, the LED lens according to Patent Document 1 has a problem that a circular belt-shaped dark portion (a portion darker than the periphery) occurs near the optical axis of the LED, and a hot spot (a portion brighter than the periphery) in the optical axis portion of the LED. ) Occurs.

US Pat. No. 7,348,723

  The present invention is to solve the above-described problems, and includes a phenomenon in which a circular belt-shaped dark portion is generated near the optical axis of the LED, and a phenomenon in which a hot spot is generated in the optical axis portion of the LED. An LED lens that can improve the above is provided.

  An LED lens according to an embodiment of the present invention is an LED lens for uniformly diffusing light emitted from an LED, an incident surface on which light emitted from the LED enters the lens, and the lens through the incident surface. An exit surface for emitting the light incident on the inside of the lens to the outside of the lens, and the exit surface has a first exit surface that forms a curved surface convex toward the LED on a vertical cross section, and the first exit surface. A second emission surface that is positioned around the surface and forms a curved surface that is convex on the opposite side of the LED, and an inflection point site that exists at a connection portion between the first emission surface and the second emission surface. Has a convex portion having a convex shape upward on a vertical cross section, and the convex portion has a circular band shape surrounding the inflection point existing in a circular shape around the optical axis of the LED on the plane. Can be formed.

  The LED lens according to an embodiment of the present invention has a first convex portion and a second convex portion that have a convex shape upward on the vertical cross section on the emission surface, and a circular strip shape on the plane. Is further formed, and the first block portion is formed on the first emission surface in a state of being spaced a predetermined distance from the projection toward the first emission surface side, and the second projection portion is formed from the projection portion. It may be formed on the second emission surface with a predetermined distance from the second emission surface side.

  In the LED lens according to an embodiment of the present invention, the first convex portion and the second convex portion may be symmetric with respect to the convex portion on a vertical cross section.

  According to the LED lens according to an embodiment of the present invention having the above-described configuration, a phenomenon in which a circular belt-like dark portion occurs near the optical axis of the LED and a phenomenon in which a hot spot occurs in the optical axis portion of the LED. There is an effect that can be improved.

  The effects according to the present invention are not limited to the effects mentioned above, and other effects that are not mentioned can be obtained from the description of the claims and the detailed description from the general knowledge in the technical field to which the present invention belongs. It will be clearly understood by those who have it.

It is a vertical sectional view showing an LED lens according to an embodiment of the present invention. FIG. 2 is a schematic plan view of FIG. 1. It is a figure which shows the result of having simulated the light distribution of the light radiate | emitted through the lens which concerns on FIG. It is the figure which expanded the "B" part of FIG. FIG. 2 is an enlarged view of an “A” area in FIG. 1. It is a vertical sectional view showing an LED lens according to another embodiment of the present invention. It is the figure which expanded the "A" area | region of FIG. FIG. 7 is a schematic plan view of FIG. 6. It is a vertical sectional view showing an LED lens according to another embodiment of the present invention. FIG. 10 is a schematic plan view of FIG. 9. It is a figure which shows the result of having simulated the light distribution of the light radiate | emitted through the lens which concerns on FIG. It is the figure which expanded the "B" part of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily carry out the embodiments.

  While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are described in detail below. However, there is no intention to limit the invention to the particular forms disclosed, but rather the invention includes all modifications, equivalents and substitutions consistent with the spirit of the invention as defined by the claims.

  On the other hand, in the accompanying drawings, the thickness and size are exaggerated for the sake of clarity of the specification, and therefore the present invention is based on the relative size and thickness shown in the accompanying drawing. Not limited.

  FIG. 1 is a vertical sectional view showing an LED lens according to an embodiment of the present invention.

  Referring to FIG. 1, an LED (Light Emitting Diode) lens 10 according to an embodiment of the present invention includes an incident surface 20 on which light L <b> 1 emitted from the LED 11 enters the lens 10, and the interior of the lens 10 through the incident surface 20. And an emission surface 30 for emitting the light L2 incident on the lens 10 to the outside of the lens 10.

  The LED lens 10 according to an embodiment of the present invention includes a bottom surface 13, a housing groove 14 that is formed at the center of the bottom surface 13 and houses the LED 11, and the bottom surface 13 and the light exit surface 30. And a leg 17 provided at a lower portion of the flange 15.

  Here, the incident surface 20 may be an inner surface of the receiving groove 14.

  That is, the light L1 emitted from the LED 11 housed in the housing groove 14 can enter the inside of the lens 10 through the incident surface 20 that is the inner surface of the housing groove 14.

  In addition, the emission surface 30 is located around the first emission surface 32 having a curved shape convex toward the LED 11, that is, a curved surface shape convex downward, and is convex to the opposite side of the LED 11. An inflection point 37 exists at a connection portion between the first emission surface 32 and the second emission surface 34, including a curved surface shape, that is, a second emission surface 34 having a curved surface shape convex upward.

  As described above, when the exit surface 30 includes the first exit surface 32 having a curved surface shape convex downward and the second exit surface 34 having a curved surface shape convex upward, the inside of the lens 10 through the entrance surface 20. The light L2 incident on the lens can be emitted to the outside of the lens 10 through the emission surface 30 in a uniformly diffused state.

  FIG. 2 is a schematic plan view of FIG.

  As can be seen from FIG. 2, the planar shape of the entrance surface 20 and the exit surface 30 may have a substantially circular shape centering on the optical axis 12 of the LED 11, and the flange 15 is on both sides from the exit surface 30. Can protrude.

  The first exit surface 32 is a central region including the optical axis 12 of the LED 11 in the region on the plane of the exit surface 30, and the second exit surface 34 is the first exit surface in the region on the plane of the exit surface 30. An inflection point 37 that is an edge region surrounding the first output surface 32 and the second output surface 34 exists in a circular shape centering on the optical axis 12 of the LED 11 on a plane. .

  FIG. 3 is a diagram showing the result of simulating the light distribution of light emitted through the lens according to FIG. 1, and FIG. 4 is an enlarged view of the “B” portion of FIG.

  Referring to FIGS. 3 and 4, the light distribution by the LED lens 10 according to FIG. 1 confirms that a dark portion b, which is darker than the substantially circular belt-shaped periphery, occurs near the optical axis 12 of the LED 11. In addition, it can be confirmed that a hot spot h which is a brighter part than the surroundings is generated at the optical axis 12 portion of the LED 11, but the darkness b and the hot spot h as described above make the light uniformity. The problem of falling occurs.

  FIG. 5 is an enlarged view of the inflection point region, and is an enlarged view of the “A” region of FIG. 1.

  As can be seen from FIG. 5, the light L3 emitted to the outside of the lens 10 through the first emission surface 32 and the light L4 emitted to the outside of the lens 10 through the second emission surface 34 are substantially in the upper region of the inflection point 37. Thus, a dark part region C is formed. Due to such a dark part region C, a substantially circular belt-like dark part b is generated near the optical axis 12 in the light distribution.

  This is because the shapes of the first emission surface 32 and the second emission surface 34, that is, the first emission surface 32 has a curved surface shape that protrudes downward, whereas the second emission surface 34 has a curved surface that protrudes upward. This is a phenomenon that occurs because of having a shape.

  More specifically, as can be seen from the drawings, the first emission surface 32 has a curved surface shape that protrudes downward, and the second emission surface 34 has a curved surface shape that protrudes upward. A difference occurs between the refraction angle of the light L3 emitted to the outside of the lens 10 through 32 and the refraction angle of the light L4 to be emitted to the outside of the lens 10 through the second emission surface 32, and this causes the first emission. Since the refraction angle of the light emitted to the outside of the lens 10 changes abruptly with reference to the inflection point 37 where the surface 32 and the second emission surface 34 are connected, the light emitted to the region approximately above the inflection point 37. Is significantly reduced, and thereby the dark area C is formed.

  On the other hand, although not shown, the reason why the hot spot h occurs at the optical axis 12 portion of the LED 11 is due to Fresnel reflection that occurs when the LED 11 exits the lens 10 through the exit surface 30.

  That is, Fresnel reflection is a reflection that occurs when light passes through a boundary surface between materials having different refractive indexes, and part of the light emitted through the emission surface 30 due to such Fresnel reflection. The light reflected on the bottom surface 20 is reflected on the bottom surface 20 in this way, and is reflected from the bottom surface 20 toward the optical axis 12 site. A hot spot h is generated.

  FIG. 6 is a vertical sectional view showing an LED lens according to another embodiment of the present invention, and FIG. 7 is an enlarged view of the inflection point portion of FIG. FIG. 8 is an enlarged view, and FIG. 8 is a schematic plan view of FIG.

  The LED lens 40 according to this embodiment has a problem that occurs in the light distribution of the lens 10 according to FIG. 1, that is, a phenomenon in which a circular belt-shaped dark portion b is generated near the optical axis 12 of the LED 11 and the optical axis. In order to improve the phenomenon of occurrence of hot spots h at 12 sites, a convex portion 42 is formed at the inflection point 37 instead of removing the inflection point 37 as compared with the lens 10 according to FIG. Since there is a difference in terms of the description, the detailed description of the other configurations and the drawing symbols are referred to the detailed description of the lens 10 according to FIG. 1 and the drawing symbols.

  Referring to FIGS. 6 to 8, the LED lens 40 according to the present embodiment includes a convex portion 42 formed at the inflection point 37 and having a convex shape upward in the vertical cross section.

  Thus, if the convex part 42 is formed in the inflection point 37 site | part, the circular strip | belt-shaped dark part b which generate | occur | produces on the light distribution distribution of the lens 10 which concerns on FIG. Can be improved.

  More specifically, as can be seen from FIG. 7, if the convex portion 37 is formed at the inflection point 37, the light L <b> 5 emitted to the outside of the lens 40 through the inflection point 37 is emitted through the convex 37. As a result, the light is refracted and emitted in the direction of the dark region C generated when there is no convex portion 37, and thereby, a circular band-shaped dark portion b on the light distribution generated by the dark region C Can be improved.

  Further, the convex portion 42 formed at the inflection point 37 disperses the light that is reflected by the Fresnel from the emission surface 30 from the bottom surface 13 and is scattered toward the optical axis 12 of the LED (scattering), or the inflection. By gathering above the point 37, the hot spot h at the site of the optical axis 12 generated on the light distribution of the lens 10 according to FIG. 1 as seen from FIGS. 3 and 4 can be improved. become.

  Further, as can be seen from FIG. 8, the convex portion 42 is formed so as to surround the inflection point 37, ie, the inflection point 37. It can be formed in the shape of a circular band surrounding the inflection point 37 that exists in a circular form centered on the axis 12.

  Of course, although not shown in the drawing, the convex portions 42 are not formed in a circular belt shape, but are formed in a state of being spaced apart by a predetermined distance in the circumferential direction of the inflection points 37 existing in a circular shape on a plane. May be.

  However, as can be seen from FIG. 8, the convex portion 42 is formed in a circular belt shape that surrounds the inflection point 37, and a plurality of the convex portions 42 are formed at a predetermined interval in the circumferential direction. Furthermore, it can be diffused uniformly, which is preferable.

  FIG. 9 is a vertical sectional view showing an LED lens according to another embodiment of the present invention, and FIG. 10 is a schematic plan view of FIG.

  Referring to FIGS. 9 and 10, the LED lens 40 according to the present embodiment includes, in addition to the convex portion 42, the first convex portion 43 having a convex shape upward on the vertical cross section, similarly to the convex portion 42. The second convex portion 44 can be further included.

  The first convex portion 43 can be formed on the first outgoing surface 32 with a predetermined distance from the convex portion 42 toward the first outgoing surface 32, and the second convex portion 44 is formed from the convex portion 42 to the second outgoing surface. It may be formed on the second emission surface 34 with a predetermined distance from the side 34.

  Further, as can be seen from FIG. 10, the first convex portion 43 and the second convex portion 44 can be formed in a circular band shape centering on the optical axis 12 of the LED 11 on the plane, like the convex portion 42.

  Thus, if the first convex portion 43 and the second convex portion 44 are further formed in addition to the convex portion 42, a circular belt-shaped dark portion b is generated near the optical axis 12 as in the lens 10 according to FIG. The phenomenon can be further improved.

  In particular, if the first convex portion 43 and the second convex portion 44 are further formed in addition to the convex portion 42, the light reflected by the Fresnel from the emission surface 30 is reflected again from the bottom surface 13 and is reflected on the optical axis 12 of the LED. Since the light which goes to can be further disperse | distributed, the phenomenon that the hot spot h generate | occur | produces in the optical axis 12 site | part like the lens 10 which concerns on FIG. 1 can further be improved now.

  Further, the first convex portion 43 and the second convex portion 44 may be formed so as to be symmetric with respect to the convex portion 42 on the vertical cross section. Then, it is possible to further improve the phenomenon in which the dark portion b is generated near the optical axis 12 and the phenomenon in which the hot spot h is generated at the optical axis 12 site.

  FIG. 11 is a diagram showing a result of simulating a light distribution of light emitted through the lens according to FIG. 9, and FIG. 12 is an enlarged view of a “B” portion of FIG.

  As can be seen from FIGS. 11 and 12, the light distribution of the lens 40 according to the present embodiment is closer to the optical axis 12 than that of FIGS. 3 and 4 showing the light distribution of the lens 10 according to FIG. It can be seen that the phenomenon of occurrence of the dark portion b in FIG. 6 and the phenomenon of occurrence of the hot spot h at the optical axis 12 site have been improved.

  That is, the dark portion b, which is a circular band, is generated near the optical axis 12 on the screens of FIGS. 3 and 4, but the dark portion b is substantially distinguished from the surroundings on the screens of FIGS. It can be confirmed that it has been improved to the extent that it cannot be attached.

  In particular, the shoulder forms on both sides of the optical axis 12 in the graphs of FIGS. 3 and 4 can be confirmed from the graphs of FIGS. The occurrence of the shoulder shape as described above in the graph means that the dark portion b darker than the surroundings is generated. Therefore, the absence of the shoulder shape in the graphs of FIGS. This indicates that the phenomenon of occurrence has been improved.

  Further, it can be confirmed that the brightness of the optical axis 12 site on the screen of FIGS. 11 and 12 is not brighter than the brightness of the optical axis 12 site on the screen of FIGS. This indicates that the phenomenon of occurrence of the hot spot h at the optical axis 12 site has been improved.

  In particular, it can be confirmed that the optical axis 12 portion is sharpened upward in the graphs of FIGS. 3 and 4 but has been changed to a flat shape in the graphs of FIGS. 11 and 12. This indicates that the phenomenon of occurrence of hot spots h at the optical axis 12 site has been improved.

  As discussed above, according to the present invention, a convex portion is formed at the inflection point portion, thereby causing a phenomenon that a circular belt-shaped dark portion is generated near the optical axis of the LED, and a hot spot at the optical axis portion of the LED. It can be said that the embodiment can be changed into various forms. Therefore, the present invention is not limited by the embodiments disclosed in the present specification, and all forms that can be changed by those having ordinary knowledge in the technical field to which the present invention belongs also belong to the scope of the present invention. I can say that.

Claims (3)

In the LED lens for uniformly diffusing the light emitted from the LED,
An incident surface on which light emitted from the LED is incident on the inside of the lens, and an output surface for emitting light incident on the inside of the lens through the incident surface to the outside of the lens,
The emission surface has a first emission surface that forms a convex curved shape on the LED side in a vertical section, and a convex curved shape that is positioned around the first emission surface and that protrudes on the opposite side of the LED. A second exit surface that
A convex part having a convex shape upward is formed on a vertical cross section at the inflection point portion present in the connection part of the first emission surface and the second emission surface,
The LED lens according to claim 1, wherein the convex portion is formed in a circular belt shape surrounding an inflection point that exists in a circular shape around the optical axis of the LED on a plane. The emission surface has a convex shape upward on a vertical cross-section, and is further formed with a first convex portion and a second convex portion having a circular band shape on a plane,
The first block portion is formed on the first emission surface with a predetermined distance from the convex portion toward the first emission surface.
2. The LED lens according to claim 1, wherein the second convex portion is formed on the second emitting surface in a state of being separated from the convex portion toward the second emitting surface by a predetermined distance. .   The LED lens according to claim 2, wherein the first convex portion and the second convex portion are symmetrical with each other with respect to the convex portion on a vertical cross section.

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