JP2010251073A - Lens for lighting and lighting system equipped with this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain luminance unevenness of two round belt shapes around white color light at the center of an irradiation face without degrading brightness. <P>SOLUTION: An open end part 27 of a recessed part as a boundary part of a second incident face 21 and a total reflection face 22 is processed into a shape other than a flat face. For instance, an R chamfering process (a process of rounding corners so as a cross section to be a given radius) is applied to a connection part of the open end part 27 and the second incident face 21. Moreover, a first incident face 20 is processed into a shape other than a flat face. For instance, a process of forming a groove part 31 with an arc-shaped cross section is applied to the first incident face 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an illumination lens that controls light distribution characteristics of white light emitted from a white light emitting diode, and an illumination device provided in an illumination device including the illumination lens.

  Conventionally, spot illumination devices that illuminate a specific area by irradiating light in a specific direction have been used for applications such as auxiliary illumination, ceiling illumination, and showcase illumination. In recent years, white light-emitting diodes (white LEDs) have been used as light sources for spot illumination devices.

  White light-emitting diodes are small, power-efficient and emit bright colors, are semiconductor elements, so there is no worry about running out of the ball, etc., excellent initial drive characteristics, and strong against repeated vibration and on / off lighting, etc. It has the characteristics of.

  The current mainstream of white light emitting diodes is a method using a phosphor, and this type of white light emitting diode is generally called a blue-yellow pseudo white light emitting diode.

  FIG. 1 is a diagram showing an example of a white light emitting diode. This white light emitting diode 1 is formed by covering a plurality of blue diode light emitting elements 3 arranged on a substrate 2 with a YAG phosphor 4. Composed. The white light emitting diode 1 obtains white light by mixing the blue light emitted from the light emitting element 3 and incident on the phosphor 4 with the yellow light generated as fluorescence in the phosphor 4.

  However, in such a white light emitting diode 1, the light beam emitted from the emission surface 5 of the white light is emitted with respect to white light (center light) having an emission angle of 0 ° emitted in the surface normal direction of the emission surface 5. Divergent over a wide angle. For this reason, in order to use the white light emitting diode 1 as a light source of a spot illuminating device, the countermeasure for condensing the white light radiate | emitted from the output surface 5 in the direction of an irradiated surface is needed.

  Further, as a characteristic of such a white light emitting diode 1, among the light beams emitted from the emission surface 5, white light at the central portion having a small emission angle with respect to the emission surface 5 becomes bluish white light, and the emission surface 5. The white light in the peripheral portion having a large emission angle with respect to the light becomes yellowish white light. As a result, color unevenness due to bluish white light and yellowish white light occurs on the irradiated surface.

  Therefore, in order to use the white light emitting diode as the light source of the spot illumination device, it is necessary to take measures for suppressing such color unevenness due to blue light and yellow light.

  A technique for condensing the white light emitted from the emission surface in the direction of the irradiated surface and suppressing the color unevenness of the irradiated surface due to the bluish white light and the yellowish white light. Patent Document 1 discloses this.

  In Patent Document 1, a lens is disposed on the emission side of a white light emitting diode, and light diffusion processing is performed on a lens configuration surface existing on an optical path of yellowish white light, thereby obtaining yellowish white light. The white light emitted from the white light-emitting diode is diffused and condensed toward the irradiated surface, and the bluish white light that reaches the irradiated surface is mixed with the yellowish white light. Reduce color unevenness.

JP 2007-5218 A

  Here, it is ideal that the image of the illuminated surface of the spot illumination device has the highest illuminance at the center of the illuminated surface, and the illuminance decreases smoothly with distance from the center.

  The spot illuminating device described in Patent Literature 1 performs light diffusion processing on the lens constituent surface on the optical path, thereby suppressing the occurrence of color unevenness due to blue light and yellow light, and light as shown in FIG. Occurrence of two annular illuminance irregularities (annular zones A and B having higher illuminance than the surroundings) that occur when the diffusion process is not performed is also suppressed.

  However, although the spot illumination device described in Patent Document 1 can suppress the occurrence of color unevenness and illuminance unevenness on the irradiated surface, light traveling in an unnecessary direction is generated by the light diffusion process. The illuminance on the irradiated surface decreases.

  The present invention has been made in view of the above points, and an illumination lens capable of suppressing the occurrence of two ring-shaped illuminance unevenness on the irradiated surface without reducing the brightness of the irradiated surface. And it aims at providing an illuminating device provided with the same.

  In the illumination lens of the present invention, white light emitted from a point light-emitting device is incident, and the incident white light is controlled to light having a desired light distribution characteristic, and then toward the irradiated surface side. An illumination lens to be emitted, wherein the illumination lens is formed on a light emitting device facing surface portion disposed to face the light emitting device, and on a side opposite to the light emitting device with respect to the light emitting device facing surface portion An emission surface portion; and a side surface portion extending from an outer peripheral end portion of the light emitting device facing surface portion toward an outer peripheral end portion of the emission surface portion, wherein the white light is emitted from the illumination lens to the light emitting device facing surface portion. A recess for allowing the light to enter is formed, the recess extends from the outer peripheral end of the first incident surface orthogonal to the optical axis toward the light emitting device, The diameter gradually increases toward the light emitting device. A second incident surface, and the side surface portion has a total reflection surface that totally reflects the light incident on the second incident surface toward the output surface portion, and the output surface portion includes the second incident surface, A light incident surface that emits light incident on the first incident surface and light incident on the second incident surface and totally reflected by the total reflection surface toward the irradiated surface; A configuration is adopted in which at least one of the opening end portion of the recess, which is a boundary portion between the second incident surface and the total reflection surface, and the first incident surface has a shape other than a flat surface.

  Moreover, the illuminating device of this invention is equipped with the said dotted | punctate light-emitting device and the said lens for illumination, and takes the structure illuminated with the light radiate | emitted from the said lens for illumination.

  According to the present invention, two annular illuminances around the white light at the center of the irradiated surface are obtained without reducing the brightness by processing the opening end or the first incident surface into a shape other than the flat surface. Unevenness can be suppressed.

The figure which showed an example of a white light emitting diode Schematic diagram of an image of the illuminated surface of a spot illumination device using a conventional white light emitting diode as a light source The figure which shows the shape of the lens for illumination which concerns on one embodiment of this invention, and an illuminating device The figure which looked at the lens for illumination of FIG. 3 from the white light emitting diode side The figure which looked at the lens for illumination of FIG. 3 from the irradiated surface side The figure explaining the cause of ring A The expanded sectional view of the lens for illumination concerning one embodiment of the present invention The figure explaining that the illumination intensity nonuniformity of the annular zone A is suppressed The figure explaining the cause of ring B generation The figure explaining that the illumination intensity nonuniformity of the annular zone B is suppressed. The figure which shows the experimental result done in order to demonstrate the effect by one embodiment of this invention The figure which shows the experimental result done in order to demonstrate the effect by one embodiment of this invention

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Schematic configuration of illumination lens and illumination device)
First, to collect the white light emitted from the exit surface in the direction of the illuminated surface and to suppress uneven color on the illuminated surface due to bluish white light and yellowish white light The technique will be described in detail.

  FIG. 3 is a diagram showing shapes of the illumination lens and the illumination device according to the embodiment of the present invention. As shown in FIG. 3, the spot illumination lens 7 in the present embodiment is disposed to face a white light emitting diode 8 as a dot-like light emitting device that emits white light. The spot illumination device 7 and the white light emitting diode 8 constitute a spot illumination device. The spot illumination lens 7 can be formed at low cost by injection molding of a resin material such as PMMA (polymethyl methacrylate resin).

The white light emitting diode 8 has a light emitting unit 10 made of a combination of a light emitting element of a blue light emitting diode and a phosphor. Emitting unit 10 from the exit surface 11, the light beam of the white light over a predetermined range of angles about the WL ₀ (light is emitted toward the surface normal direction of the emission surface 11) that exit angle 0 ° of the white light Exit.

In the present embodiment, among the white light emitted from the light emitting unit 10, white light at a central portion with a small emission angle from the emission surface 11 centering on the white light WL ₀ (bundled in a broken line frame in FIG. 3). The white light WL _B which is bluish white, and the white light in the peripheral portion having a large emission angle from the emission surface 11 (light bundled with a two-dot broken line frame in FIG. 3) is yellowish white. It becomes light WL _Y.

  The white light emitting diode 8 includes a plano-convex condensing lens 16 having a flat surface 14 facing the white light emitting side of the light emitting unit 10 and a convex surface 15 facing the spot illumination lens 7 side. The condenser lens 16 is accommodated in the housing 17 together with the light emitting unit 10.

  Therefore, the white light emitted from the light emitting unit 10 is collected by the condenser lens 16 and then emitted from the white light emitting diode 8. Of the white light emitted from the light emitting unit 10, white light having an emission angle of 0 ° passes through the optical axis (not shown) of the condenser lens 16 and maintains the emission angle of 0 ° from the surface vertex of the convex surface 15. It is emitted.

  White light emitted from the white light emitting diode 8 is incident on the spot illumination lens 7. The spot illumination lens 7 emits the incident white light toward the irradiated surface 18 side after being controlled to have a desired light distribution characteristic.

  That is, the spot illumination lens 7 is formed on the opposite side of the light emitting diode facing surface portion from the light emitting diode facing surface portion of the white light emitting diode 8 as the light emitting device facing surface portion. And a side surface portion extending from the outer peripheral end portion of the light emitting diode facing surface portion toward the outer peripheral end portion of the output surface portion.

(Description of light emitting diode facing surface)
A concave portion for allowing the white light emitted from the white light emitting diode 8 to enter the inside of the spot illumination lens 7 is formed on the light emitting diode facing surface portion. As shown in FIG. 3, the recess has a first incident surface 20 and a second incident surface 21.

  The first incident surface 20 is usually a circle in a plan view (FIG. 4) when viewed from the side where the white light emitting diode is arranged in the direction of the optical axis OA (dotted line in FIG. 3) of the spot illumination lens 7. It is formed to be a flat shape. In the present embodiment, as will be described in detail below, the first incident surface 20 is subjected to predetermined processing.

  The optical axis OA of the spot illumination lens 7 is a center line assumed on the center of a three-dimensional light beam emitted from the spot illumination lens 7, and this optical axis OA is the first incident surface 20. Pass through the center point. In the state of FIG. 1, the optical axis OA of the spot illumination lens 7 is assumed to be the center line assumed on the center of the three-dimensional light beam emitted from the condenser lens 16 (that is, the optical axis of the condenser lens 16). ).

The white light WL _{B which} is bluish in the central portion of the white light emitted from the light emitting unit 10 enters the first incident surface 20 after passing through the condenser lens 16, and this incident white light The light WL _B travels (transmits) through the spot illumination lens 7 after being refracted at a predetermined refraction angle according to Snell's law toward the optical axis OA side. However, of the white light WL _B , the white light WL ₀ having an emission angle of 0 ° passes through the optical axis OA of the spot illumination lens 7 without being refracted after being incident on the center point of the first incident surface 20. Then proceed in the spot illumination lens 7.

  In FIG. 3, for the sake of convenience, the optical path for only the upper half of the spot illumination lens 7 with respect to the optical axis OA is shown. However, the spot illumination lens 7 rotates around the optical axis OA. In consideration of being formed in a symmetrical shape, the lower half of the optical path of the optical axis OA in the spot illumination lens 7 is a line-symmetric optical path of the upper half of the optical path with the optical axis OA as a reference line. It becomes.

Here, as shown in FIG. 3, if the first incident surface 20 is formed as a flat surface, the incident angle of the white light WL _B with respect to the first incident surface 20 can be reduced (white light WL ₀ is 0 °). . Therefore, the refraction angle of the white light WL _{B on} the first incident surface 20 can be kept small.

Thus, in this embodiment, it is possible to white light WL _B incident on the first incident surface 20, to prevent the color separated into blue light and yellow light.

  On the other hand, the second incident surface 21 is connected to the first incident surface 20, extends from the outer peripheral end of the first incident surface 20 toward the white light emitting diode 8, and is on the white light emitting diode 8 side. The diameter gradually increases as it goes to. More specifically, the second incident surface 21 is formed in a tapered surface with the optical axis OA as the central axis that increases in diameter toward the white light emitting diode 8 side.

Then, the second incident surface 21, of the white light emitted from the light emitting unit 10, the white light WL _Y of yellowish peripheral portion is incident upon passing through the condenser lens 16. The incident white light WL _Y is propagating through spot illumination lens 7 to face the total reflection surface 22 to be described later on that towards the side away from the optical axis OA refracted at a predetermined angle of refraction.

Here, if the second incident surface 21 is formed on a tapered surface having the optical axis OA as a central axis so that the diameter increases toward the white light emitting diode 8 side, the emission angle from the emission surface 11 is large. incidence angle when the white light WL _Y is incident on the second incident surface 21 is suppressed. Therefore, the refraction angle of the white light WL _Y at the second incident surface 21 is suppressed small.

Thus, in this embodiment, it is possible to white light WL _Y incident on the second incident face 21, to prevent the color separated into blue light and yellow light.

  The opening end 27 of the concave portion, which is the boundary portion between the second incident surface 21 and the total reflection surface 22, is used as a positioning portion for fixing the spot illumination lens 7 to the housing 17 of the white light emitting diode 8. Note that the opening end 27 is usually shaped so that the boundary between the second incident surface 21 and the total reflection surface 22 is sharp in consideration of the handling of the spot illumination lens 7 and the positioning stability to the housing 17. It is formed into an annular flat surface by chamfering. However, in the present embodiment, as will be described in detail below, the opening end 27 is subjected to predetermined processing.

(Description of side part)
As shown in FIG. 3, the side surface portion has a total reflection surface 22 and a flange portion 28.

  The total reflection surface 22 is formed so that the diameter gradually increases from the light emitting diode facing surface side toward the emission surface side (right direction in FIG. 3). In other words, the total reflection surface 22 is light that extends from the outer periphery of the opening end portion 27 toward the irradiated surface 18 side to the flange portion 28 and has a diameter that increases toward the irradiated surface 18 side. It is formed on a tapered surface with the axis OA as the central axis. The total reflection surface 22 is formed over almost the entire outer peripheral surface of the spot illumination lens 7.

This total reflection surface 22, the white light WL _Y of yellowish which has traveled the internal spot illumination lens 7 is incident on the second incident face 21, at an angle of incidence greater than the critical angle. Then, the white light WL _Y incident on the total reflection surface 22 is totally reflected by the total reflection surface 22 toward the emission surface portion side. The total reflection surface white light WL _Y totally reflected by 22, toward the exit surface side propagating through spot illumination lens 7.

At this time, since the total reflection plane 22 refraction does not occur, is no color separation of white light WL _Y incident on the total reflection surface 22.

(Explanation of exit surface)
The exit surface portion is an exit surface formed as a convex aspheric surface facing the irradiated surface 18 at a position facing the first entrance surface 20 and the second entrance surface 21 in the optical axis OA direction with a lens thickness therebetween. 23.

  As shown in FIGS. 3 and 5, the emission surface 23 in the present embodiment is formed in a circular shape in a plan view, and its center point is a surface vertex that intersects the optical axis OA.

  More specifically, the exit surface 23 in the present embodiment is formed in a convex surface in which most of the region on the optical axis OA side (center side) faces the irradiated surface 18 side, and the peripheral side (radially outer side). And a partially concave convex aspherical surface having a concave surface facing the irradiated surface 18 side.

  In addition to such a configuration, for example, the emission surface 23 may be formed as a fully convex aspheric surface whose positive power becomes weaker from the optical axis OA side toward the peripheral side. In this case, the aspherical shape of the emission surface 23 may be a surface shape in which the positive power continuously decreases toward the peripheral side, or the positive power increases toward the peripheral side. The surface shape may be weakened step by step. In addition, as an example of the surface shape that gradually decreases, the surface shape on the optical axis OA side having a constant positive power and the peripheral side having a constant positive power weaker than the power of this surface shape. The surface shape which connected the surface shape can be mentioned.

Further, in the present embodiment, a region in a predetermined range on the optical axis OA side of the emission surface 23 is a first emission surface 24, and the first incidence surface 24 has a first incidence surface. and incident on the surface 20 is white light WL _B bluish which has traveled the internal spot illumination lens 7 is incident. The white light WL _B incident on the first exit surface 24 is refracted at a predetermined refraction angle on the first exit surface 24 and then travels from the first exit surface 24 toward the irradiated surface 18 side. Are emitted.

  Further, in the present embodiment, a region in a predetermined range on the peripheral side of the emission surface 23, which is continuously provided so as to surround the first emission surface 24 at the outer peripheral end portion of the first emission surface 24. The region is a second emission surface 25, and the second emission surface 25 is formed so that the positive power is weaker than that of the first emission surface 24. In the present specification, the fact that the positive power is weak includes that the power is negative (concave).

After entering the second incident surface 21, the yellowish white light WL _Y that has been totally reflected by the total reflection surface 22 and travels inside the spot illumination lens 7 is incident on the second emission surface 25. To do. Then, the white light WL _Y incident on the second exit surface 25, the second exit surface 25 on which is refracted at a predetermined refraction angle, toward the irradiated surface 18 side from the second exit surface 25 Are emitted.

At this time, the second emission surface 25, since the positive power is suppressed, it is possible to suppress the angle of incidence of the white light WL _Y for the second emission surface 25.

Thus, in this embodiment, it is possible to white light WL _Y incident on the second exit surface 25, to prevent the color separated into blue light and yellow light.

Then, the bluish white light WL _B emitted from the first emission surface 24 and the yellowish white light WL _Y emitted from the second emission surface 25 are transmitted from the spot illumination lens 7. The irradiated surfaces 18 separated by a predetermined distance in the direction of the optical axis OA are irradiated as white circular irradiation light in a mixed state.

(effect)
As described above, according to the spot illumination lens 7 in the present embodiment, the occurrence of color separation on the first incident surface 20 and the second emission surface 25 can be suppressed extremely effectively. The uneven color of the irradiation light on the irradiation surface 18 can be sufficiently suppressed. Specifically, for example, it is possible to suppress the formation of a dark yellow portion (yellow ring) at the outer peripheral edge of the irradiated light irradiated on the irradiated surface 18.

(Modification)
A part of the white light WL _Y incident on the second incident face 21, may be allowed to exit from the first light exit surface 24 is made incident on the first light exit surface 24.

More preferably, the light distribution characteristics of the white light WL _B when the bluish white light WL _B incident on the first incident surface 20 is emitted from the first emission surface 24, and the second incident surface 21. the difference of the white light WL to each other match or characteristics and light distribution characteristic of _Y when white light WL _Y of yellowish incident is emitted from the exit surface 23 (exit surface) (for example, a spreading way of the light beam The light intensity [cd] or the illuminance [lx] at each measurement angle, which will be described later, is approximated to a level within a predetermined value. At this time, since the degree of overlap between the spread of the light beam emitted from the first emission surface 24 and the spread of the light beam emitted from the second emission surface 25 greatly affects the degree of suppression of color unevenness. It is important to match or approximate the light distribution characteristics of the two white lights WL _B and WL _Y to each other.

  If comprised in this way, the color nonuniformity of the irradiated light in the to-be-irradiated surface 18 can be suppressed still more effectively.

(Cause of ring A)
Next, the cause of the occurrence of the annular zone A (illuminance unevenness) will be described.

There may be a gap between the housing 17 and the open end 27. Therefore, some of yellowish emitted from the white light emitting diode 8 white light WL _Y is incident on the opening end portion 27 (usually a flat surface formed annularly by chamfering).

The white light WL _Y incident on the opening end 27 is reflected by the total reflection surface 22 even though it is originally unnecessary light (directly without passing through the total reflection surface 22 depending on the incident angle). The light is emitted from the emission surface 23.

When the opening end 27 is a flat surface, as shown in FIG. 6, the white light WL _Y incident on the opening end 27 is a lens of the spot illumination lens 7 until it is emitted from the emission surface 23. The light is refracted on the component surface and condensed so as to approach the optical axis OA. Due to this light, an annular zone A is generated on the irradiated surface.

(Countermeasures for suppressing uneven illumination of ring A)
Next, a countermeasure for suppressing the illuminance unevenness of the annular zone A will be described.

  In the present embodiment, as shown in FIG. 7, R chamfering is performed on the connecting portion between the opening end portion 27 and the second incident surface 21 (processing that takes a corner so that the cross section has a predetermined radius). .

Thereby, as shown in FIG. 8, the white light WL _Y incident on the opening end 27 is dispersed in the process until it is emitted from the emission surface 23. As a result, the illuminance unevenness of the annular zone A can be suppressed.

  Not only the R chamfering process but also the opening end 27 is processed into a shape other than a flat surface, such as roughing the opening end 27, thereby suppressing unevenness in the illuminance of the annular zone A. Can do.

(Causes of ring zone B)
Next, the cause of the ring zone B (illuminance unevenness) will be described.

The light emitted from the condenser lens 16 of the white light emitting diode 8 includes white light WL _B and WL indicated by a line extending from one intersection point of the optical axis OA and the surface of the light emitting unit 10 as shown in FIG. _In addition to the light rays used when designing the shape of the basic spot illumination lens 7 of _Y , there is stray light generated by internal reflection or the like in the condenser lens 16.

FIG. 9 shows an optical path of stray light that causes the annular zone B to be generated. This stray light is a light having a smaller amount of light than the white light WL _B and WL _Y used when designing the shape of the spot illumination lens 7.

  However, even with such a small amount of light, as shown in FIG. 9, when the light is refracted on the lens constituting surface of the spot illumination lens 7 and condensed so as to approach the optical axis OA, the irradiated surface Cause unevenness in illuminance like the annular zone B. In the present embodiment, the case where the white light-emitting diode 8 having the condensing lens 16 is used as the light source has been described. However, the light-emitting unit 10 is a light source that does not have the condensing lens 16 and has a small area. In the case where the illuminance is also present, unevenness in illuminance like the annular zone B occurs due to light emitted from other than the intersection of the optical axis OA and the surface of the light emitting unit 10.

(Countermeasures for suppressing uneven illumination of ring zone B)
Next, a countermeasure for suppressing the illuminance unevenness of the annular zone B will be described.

  In the present embodiment, as shown in FIG. 7, the first incident surface 20 is processed to form a groove 31 having a circular cross section.

Thus, as shown in FIG. 10, the white light WL _Y incident on the first incident surface 20 after being reflected by the second incidence surface 21 is dispersed in the process from the exit surface 23 to be emitted. As a result, the illuminance unevenness of the annular zone B can be suppressed.

  In addition, not only the process which forms the groove part 31, but processing the 1st incident surface 20 into shapes other than a flat surface, such as roughening the 1st incident surface 20, etc., the annular zone B Irradiance unevenness can be suppressed.

By processing the first incident surface 20 into a shape other than the flat surface, the bluish white light WL _B incident on the first incident surface 20 is also dispersed. However, the white light WL _B incident on the first incident surface 20 is more incident on the first incident light than the white light WL _Y incident on the first incident surface 20 after being reflected by the second incident surface 21. The incident angle with respect to the surface 20 is small. Therefore, even if the first incident surface 20 is processed into a shape other than a flat surface, the refraction angle of the white light WL _{B on} the first incident surface 20 can be kept small, so that the brightness on the irradiated surface hardly decreases. .

(Operations and effects of the present embodiment)
As described above, according to the present embodiment, by processing the opening end 27 or the first incident surface 20 into a shape other than the flat surface, the white light at the center of the irradiated surface can be obtained without reducing the brightness. Illuminance unevenness of two annular zones appearing around can be suppressed.

  The results of experiments conducted to demonstrate the effects of the present embodiment described above are shown in FIGS. 11 and 12, the horizontal axis represents the angle (°) from the optical axis OA on the exit surface, and the vertical axis represents the relative illuminance (no unit, logarithmic display) on the irradiated surface.

  The solid line graphs in FIGS. 11 and 12 represent the relative illuminance on the irradiated surface when the opening end 27 and the first incident surface 20 are formed into flat surfaces. As is apparent from the solid line graphs of FIGS. 11 and 12, when the opening end 27 and the first incident surface 20 are formed into flat surfaces, an annular zone A is generated around 17 ° and around 33 °. Annulus B is generated.

  The broken line graph in FIG. 11 represents the relative illuminance on the irradiated surface in the case where the opening end portion 27 is subjected to R processing. As is apparent from the broken line graph of FIG. 11, when the R end processing is performed on the opening end portion 27, unevenness in the illuminance of the annular zone A is suppressed.

  The broken line graph in FIG. 12 represents the relative illuminance on the irradiated surface when the groove 31 is provided on the first incident surface 20. As is apparent from the broken line graph of FIG. 12, when the groove portion 31 is provided on the first incident surface 20, uneven illuminance of the annular zone B is suppressed.

  The present invention is suitable for use in a white light emitting diode, a light emitting diode other than white light, an illumination lens combined with another point light source, and a spot illumination device.

7 Spot illumination lens 8 White light emitting diode 18 Irradiated surface 20 First incident surface 21 Second incident surface 22 Total reflection surface 23 Output surface 24 First output surface 25 Second output surface 27 Open end 31 Groove

Claims (6)

An illumination lens that emits white light emitted from a point-like light emitting device and emits the incident white light toward the irradiated surface side after controlling the incident white light to light having a desired light distribution characteristic. ,
The illumination lens is:
A light emitting device facing surface portion disposed to face the light emitting device; an emission surface portion formed on the opposite side of the light emitting device to the light emitting device facing surface portion; and an outer peripheral end of the light emitting device facing surface portion. A side portion extending toward the outer peripheral end of the emission surface portion,
In the light emitting device facing surface portion,
A recess for allowing the white light to enter the illumination lens is formed,
The recess is
A first incident surface orthogonal to the optical axis and a first incident surface that extends from the outer peripheral end of the first incident surface toward the light emitting device side and gradually increases in diameter toward the light emitting device side. Two incident surfaces;
The side portion is
A total reflection surface that totally reflects light incident on the second incident surface toward the exit surface;
The exit surface portion is
A light exit surface that emits light incident on the first incident surface and light incident on the second incident surface and totally reflected by the total reflection surface toward the irradiated surface;
At least one of the opening end portion of the concave portion that is a boundary portion between the second incident surface and the total reflection surface, and the first incident surface has a shape other than a flat surface.
An illumination lens characterized by that.   The illumination lens according to claim 1, wherein an R chamfering process is performed on a connecting portion between the opening end and the second incident surface.   The illumination lens according to claim 1, wherein a roughening process is performed on a surface of the opening end portion.   The illumination lens according to claim 1, wherein a groove is provided on the first incident surface.   The illumination lens according to claim 1, wherein the first incident surface is roughened.   An illumination device comprising: the point light emitting device; and the illumination lens according to any one of claims 1 to 4, wherein illumination is performed by light emitted from the illumination lens.

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