JP2006172772A - Light distribution control member, and irradiation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light distribution control member and an irradiation device, wherein utilization efficiency of light is further improved. <P>SOLUTION: The light distribution control member 2 emits an incident light flux, having a prescribed dispersion angle in the cross-section including an optical axis O as an emitting light flux, having a smaller irradiation angle than the dispersion angle in the prescribed cross-section. The light distribution control member 2 is provided with a plurality of projected line parts 23 of a cross-sectional square shape, at the incident side of the incident light flux in a region R3. The respective projected line parts 23 have a face 23a rising from the base part of the projected line parts in a closer side to the optical axis O, a face 23b rising from the base part of the projected line parts 23 at a side far from the optical axis O, and a face 23c of the tip side to be connected between the faces 23a, 23b. The incident light of the face 23c of the projected line parts 23 proceeds into the projected line parts and is emitted from the emitting face 21, after being reflected at the face 23b. In order to improve the utilization efficiency of the light, the optical axis O direction position of a corner part 23d between the faces 23b, 23c of the projected line parts 23 in the region R3 is changed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light distribution control member made of a translucent material that emits an incident light beam as an output light beam of different light distribution, and an irradiation apparatus using the same.

  Conventionally, various light distribution control members made of a translucent material that emits an incident light beam as an output light beam of different light distribution have been provided.

  As one of such light distribution control members, an inner lens of a vehicular lamp disclosed in Patent Document 1 below is provided. This inner lens is an inner lens of a vehicular lamp that is configured by a Fresnel lens that emits incident light from a light source bulb as parallel light. And a thick-walled molding surface on the base side, whereby the cross-sectional shape of the reflective prism is made quadrangular. In the inner lens, the reflection prism is disposed on the outer peripheral side, and a refractive prism having a triangular cross section is disposed on the center side with respect to the reflection prism. Further, in this inner lens, the height of the tip of the reflection system prism (that is, the position of the corner between the effective surface of the reflection system prism and the outer peripheral surface in the optical axis direction) is the same for all reflection system prisms. It was the same.

  In this inner lens, since the base portion of the reflective prism is thick, the resin can be distributed to the tip of the reflective prism without extending the molding time or applying pressure. As a result, the tip of the reflecting prism is not rounded but has an acute angle. For this reason, according to the inner lens, light incident on the tip of the prism is emitted as parallel light, light loss is reduced, and light use efficiency is increased. Further, in the inner lens, the surface opposite to the center of the reflection system prism (surface on the total light reflection side) is increased as compared with the case where the reflection system prism has a triangular cross section. And use efficiency of light increases.

Patent Document 1 listed below discloses a vehicular lamp having the inner lens and a light source bulb as an irradiation device having a light distribution control member and a light source. In this vehicular lamp, the light source bulb is disposed in a cup-shaped housing that is open on the upper side, and the inner lens is held by the upper edge of the cup-shaped housing so as to close the upper opening of the cup-shaped housing. As a result, the light source bulbs are arranged at intervals.
Japanese Patent Laid-Open No. 10-3803

  As described above, the conventional inner lens has high light use efficiency, but it is needless to say that the light use efficiency is required to be further increased. Such a request applies to other light distribution control members other than the inner lens.

  Further, in the conventional vehicle lamp, the structure as described above is adopted as the structure for holding the light distribution control member on the light source. However, the light source is, for example, a surface-mounted light emitting device or the like. If the present invention is applied to a rectangular parallelepiped shape like this, the size of the irradiation device will be increased.

  The present invention has been made in view of such circumstances, and a light distribution control member that can further increase the light use efficiency, and can increase the amount of irradiation light more efficiently by using the light distribution control member. An object is to provide an irradiation apparatus.

  Another object of the present invention is to provide an irradiation apparatus that can increase the amount of irradiation light more efficiently and can be miniaturized by improving the holding structure of the light distribution control member on the light source. And

  Furthermore, an object of the present invention is to provide an irradiation apparatus that can be reduced in size by improving the holding structure of the light distribution control member on the light source.

  As a result of the inventor's research, the height of the tip of all the reflection prisms is the same in the conventional inner lens, but by making this height different, the light utilization efficiency is further improved. Turned out to be possible. Further, when the light source has a rectangular parallelepiped outer shape, the holder that holds the light distribution control member has a cylindrical inner surface, and the cylindrical inner surface is brought into contact with only the four sides of the light source in a substantially linear manner. It has been found that, by fitting, the structure can be reduced in size while reducing the contact area with the light source and improving the heat dissipation of the light source.

  In order to solve the above problems, the light distribution control member according to the first aspect of the present invention has a predetermined divergence angle in a predetermined cross section including the optical axis. A light distribution control member made of a translucent material that emits an incident light beam as an output light beam having an irradiation angle smaller than the divergence angle in the predetermined cross section, and a plurality of first protrusions on the incident side of the incident light beam The plurality of first ridges are arranged in parallel with each other in a plan view as viewed from the optical axis direction, and each of the first ridges is on the side close to the optical axis. A first surface rising from the base of the strip, a second surface rising from the base of the first convex strip on the side far from the optical axis, and a tip side connecting the first and second surfaces A third surface of the incident light flux, and the first projections of the incident light flux. After most or all of the partial light fluxes that have reached the third surface of the portion have entered the first ridge portion from the third surface of the first ridge portion, the first ridge portion. In the predetermined cross section of the second and third surfaces of the first ridge portion so as to become a partial light beam that forms a part of the emitted light beam after being reflected by the second surface of the part Compared to the case where the angle is set, and the positions in the optical axis direction of the corners between the second and third surfaces of the plurality of first ridges in the predetermined cross section are all the same, The position of the corner portion in the optical axis direction in the predetermined cross section of at least one of the plurality of first ridge portions of the plurality of first ridge portions is increased so that the utilization efficiency of the incident light beam with respect to the emitted light beam is increased. The front in the predetermined cross section of at least one other ridge of the plurality of first ridges Wherein the optical axis direction position of the corner portions and in which is set differently.

  In the first aspect, the first to third surfaces in the conventional inner lens, on the surface opposite to the thick molding surface on the base side of the reflection prism, the effective surface on the tip side, and the center, Each corresponds. Therefore, according to the first aspect, the light use efficiency is increased for the same reason as in the conventional inner lens.

  And in the said 1st aspect, unlike the said conventional inner lens, according to the new knowledge by this inventor mentioned above, the said 2nd and 3rd of these 1st convex-line part in the said predetermined cross section Compared with the case where the positions of the corners between the surfaces in the optical axis direction are all the same, the use efficiency of the incident light flux with respect to the outgoing light flux is increased in the plurality of first ridges. The position in the optical axis direction of the corner in the predetermined cross section of at least one ridge is within the predetermined cross section of at least one other ridge of the plurality of first ridges. It is set to be different from the position of the corner in the optical axis direction. Therefore, according to the first aspect, similarly to the conventional inner lens, the optical axis at the corner between the second and third surfaces of the plurality of first protrusions in the predetermined cross section. Compared with the case where the direction positions are all the same, the light use efficiency is further increased.

  The light distribution control member according to a second aspect of the present invention is the light distribution control member according to the first aspect, wherein the plurality of first protrusions are concentric with the optical axis as a center in a plan view as viewed from the optical axis direction. Are arranged.

  This 2nd aspect gives the example of the light distribution control member which controls the light distribution of a two-dimensional direction.

  The light distribution control member according to a third aspect of the present invention is the light distribution control member according to the first aspect, wherein the plurality of first protrusions are in a direction orthogonal to the predetermined cross section in a plan view as viewed from the optical axis direction. They are arranged so as to extend linearly.

  The third aspect is an example of a so-called linear type light distribution control member that controls light distribution in a one-dimensional direction. The light distribution control member according to the third aspect is used in combination with, for example, a linear light source.

  The light distribution control member according to a fourth aspect of the present invention is the light distribution control member according to any one of the first to third aspects, wherein a second ridge portion having a triangular shape in the cross section is provided on the incident side of the incident light beam. The second ridges are aligned with the plurality of first ridges in a plan view as viewed from the optical axis direction, and are arranged on the optical axis from the plurality of first ridges. They are arranged so that they are located on the near side.

  According to this 4th aspect, the utilization efficiency of the light by the side of an optical axis can be improved more by using said 2nd convex strip part as a refractive system prism in the said conventional inner lens. Further, according to the fourth aspect, by using the second ridge portion, the first ridge portion is formed up to the vicinity of the optical axis instead of the second ridge portion. Compared to the case, the thickness of the light distribution control member in the optical axis direction can be reduced.

  The light distribution control member according to a fifth aspect of the present invention is the light distribution control member according to any one of the first to fourth aspects, wherein at least the exit region of the exit beam on the exit side surface of the exit beam forms a plane. is there.

  The light distribution control member according to a sixth aspect of the present invention is the light distribution control member according to any one of the first to fourth aspects, wherein at least the exit region of the exit beam on the exit side surface of the exit beam is a convex curved surface or a concave curved surface. It is what makes.

  In the fourth to sixth aspects, examples of the surface shape on the emission side of the light distribution control member are given. However, the first to third aspects are not limited to these examples. In the case of the fifth and sixth aspects, the irradiation angle of the emitted light can be adjusted also by the curved surface.

  An irradiation apparatus according to a seventh aspect of the present invention includes the light distribution control member according to any one of the first to sixth aspects, and a light source that emits light that becomes the incident light flux.

  According to the seventh aspect, since the light distribution control member according to the first to sixth aspects is used, it is possible to increase the irradiation light amount more efficiently than in the past.

  The irradiation device according to an eighth aspect of the present invention is the irradiation device according to the seventh aspect, wherein the light source has a rectangular parallelepiped outer shape and emits light from one surface side, and the light distribution control member is connected to the light source of the light source. The holder further includes a holder that holds an interval on one surface, the holder having a cylindrical inner surface, and the cylindrical inner surface is between four side surfaces when the one surface of the light source is the upper surface. Only the four sides are fitted in contact with each other in a substantially linear manner.

  According to the eighth aspect, not only can the amount of irradiation light be increased more efficiently as in the seventh aspect, but the cylindrical inner surface of the holder is substantially linear only on the four sides of the light source. Since the area where the holder contacts the light source can be suppressed, the heat dissipation of the light source can be increased, and the holding structure of the light distribution control member can be reduced in size. Therefore, it is possible to reduce the size of the entire irradiation apparatus.

  The shape of the cylindrical inner surface may be appropriately determined according to the shape of the one surface of the light source. For example, if the one surface is square, the shape may be cylindrical, If one surface is other than a square, it may be an elliptical cylinder. This also applies to the following ninth aspect.

  An irradiation apparatus according to a ninth aspect of the present invention has a light distribution control member made of a translucent material that emits an incident light beam as an output light beam having a different light distribution, a rectangular parallelepiped outer shape, and the above-mentioned from one surface side. A light source that emits light that becomes an incident light beam, and a holder that holds the light distribution control member on the one surface of the light source with a space therebetween, the holder having a cylindrical inner surface, and the cylindrical shape The inner surface is fitted in substantially linear contact with only four sides between the four side surfaces when the one surface of the light source is the upper surface.

  According to the ninth aspect, since the cylindrical inner surface of the holder is fitted in substantially linear contact with only the four sides of the light source, the area where the holder contacts the light source can be suppressed. As a result, the heat dissipation of the light source can be increased, the holding structure of the light distribution control member can be reduced in size, and as a result, the overall irradiation apparatus can be reduced in size.

  The irradiation apparatus according to a tenth aspect of the present invention is the irradiation apparatus according to the eighth or ninth aspect, wherein the holder is formed with a communication path that communicates the space in the vicinity of the four side surfaces to the outside of the side.

  According to the tenth aspect, the spaces near the four side surfaces of the light source communicate with the lateral outside through the communication path, so that the heat dissipation of the light source can be significantly improved.

  An irradiation apparatus according to an eleventh aspect of the present invention is the irradiation apparatus according to any one of the eighth to tenth aspects, wherein the light source is a surface-mounted light-emitting device mounted on a circuit board.

  An irradiation apparatus according to a twelfth aspect of the present invention is the irradiation apparatus according to any one of the eighth to eleventh aspects, wherein the light source is an LED.

  The eleventh and twelfth aspects are examples of the light source, but the eighth to tenth aspects are not limited to these.

  The irradiation devices according to the seventh to twelfth aspects are used as, for example, a camera flash device, a camera flash device built in a mobile phone, and various illumination devices such as a spotlight and a downlight. In addition, the light emitting unit used to constitute various devices may be used.

  ADVANTAGE OF THE INVENTION According to this invention, the light distribution control member which can raise the utilization efficiency of light further, and the irradiation apparatus which can raise irradiation light quantity more efficiently by using this can be provided.

  In addition, according to the present invention, it is possible to provide an irradiation apparatus that can increase the amount of irradiation light more efficiently and can be downsized by improving the holding structure of the light distribution control member on the light source. Can do.

  Furthermore, according to the present invention, it is possible to provide an irradiation apparatus that can be reduced in size by improving the holding structure of the light distribution control member on the light source.

  Hereinafter, a light distribution control member and an irradiation apparatus according to the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an irradiation apparatus according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the irradiation apparatus. FIG. 3 is a perspective view of the holder main body 3a in FIGS. 1 and 2 as viewed from below. FIG. 4 is a perspective view showing a fitting state between the LED 1 and the holder body 3a in FIG.

  The irradiation apparatus according to the present embodiment is configured as a light-emitting unit used to configure various apparatuses, and as shown in FIGS. 1 and 2, a high-power LED 1 that is a kind of surface-mounted light-emitting device as a light source. And a light distribution control member 2 that emits an incident light beam from the LED 1 as an output light beam having a different light distribution, and a holder 3 that holds the light distribution control member 2 at a distance from the LED.

  The LED 1 has a rectangular parallelepiped outer shape and emits light from the upper surface side in the drawing. Further, the LED 1 emits a light beam having substantially the same divergence angle (irradiation angle) θin (for example, about 110 ° to 120 °) in any cross section including the optical axis O. FIG. 5 shows a state of an incident light beam incident on the light distribution control member 2 from the LED 1.

  The light distribution control member 2 is made of a translucent material, and emits an incident light beam having a divergence angle θin as an output light beam having an irradiation angle θout smaller than the divergence angle θin. As a material for the light distribution control member 2, for example, a light-transmitting resin such as acrylic or a heat-resistant resin having light-transmitting properties such as COP (cycloolefin polymer) or COC (cycloolefin copolymer) can be used. In the present embodiment, the light distribution control member 2 is configured in a disc shape, and all cross-sectional shapes including the optical axis O are the same, and the same light distribution control characteristics are present in any cross-section. is doing. The light distribution control member 2 will be described in detail later.

  The holder 3 is comprised from the holder main body 3a and the ring-shaped member 3b, as shown in FIG. 1 thru | or FIG. The holder body 3a and the ring-shaped member 3 are made of a heat resistant resin such as PPA (polyphthalamide), for example.

  The holder main body 3a has a hole 11 that is open up and down. The upper part of the hole 11 has a relatively large diameter according to the diameter of the light distribution control member 2, whereas the lower part of the hole 11 has a relatively small diameter according to the size of the LED 1. Yes. The peripheral wall of the lower portion of the hole 11 is a cylindrical inner surface 12. As shown in FIGS. 1 and 4, the cylindrical inner surface 12 is fitted in contact with only four sides between the four side surfaces of the LED 1. By this fitting, the holder main body 3 a is fixed to the LED 1.

  The outer peripheral portion of the light distribution control member 2 is engaged with the inner step portion 13 on the upper portion of the holder main body 3a, and the outer peripheral portion of the light distribution control member 2 is further fitted on the outer step portion 14 on the upper portion of the holder main body 3a. It is pressed by the combined ring-shaped member 3b. Thereby, the light distribution control member 2 is hold | maintained at the upper part of the holder main body 3a, and the light distribution control member 2 is hold | maintained at intervals on the light emission side surface of LED1.

  The holder body 3a is formed with a communication passage 15 that communicates the spaces near the four side surfaces of the LED 1 to the outside of the side. In the present embodiment, the communication path 15 is formed in a groove shape that opens downward, but it does not necessarily have to be open downward.

  According to the present embodiment, since the cylindrical inner surface 12 of the holder 3 is fitted substantially linearly only to the four sides of the LED 1, the area where the holder 3 contacts the LED 1 is suppressed. While being able to improve the heat dissipation of LED1, the holding structure of the light distribution control member 2 can be reduced in size, and by extension, the whole irradiation apparatus can be reduced in size. In particular, in the present embodiment, since the spaces near the four side surfaces of the LED 1 communicate with the outside of the side by the communication path 15, the heat dissipation of the LED 1 can be significantly improved.

  Next, the light distribution control member 2 will be described with reference to FIGS. 5 and 6. FIG. 5 is a cross-sectional view showing the light distribution control member 2 and also shows an incident light beam from the LED 1 as described above. 6 is an enlarged view of a part of the light distribution control member 2, FIG. 6 (a) is a half sectional view of the light distribution control member 2, and FIG. 6 (b) is a region R2 in FIG. 6 (a). FIG. 6C is an enlarged view of a partial region R2 ′, and FIG. 6C is an enlarged view of a partial region R3 ′ of the region R3 in FIG.

  For convenience of explanation, as shown in FIGS. 5 and 6, an X axis, a Y axis, and a Z axis that are orthogonal to each other are defined (the same applies to the drawings described later). The + side in the Z-axis direction may be referred to as the upper side, and the − side in the Z-axis direction may be referred to as the lower side. The Z axis is parallel to the optical axis O. The −Z side is the light incident side, and + Z is the light output side.

  The light distribution control member 2 according to the present embodiment is designed to emit an incident light beam having a divergence angle θin from the LED 1 as an outgoing light beam having an irradiation angle θout (where θout <θin).

  In the present embodiment, the light distribution control member 2 is configured as a rotating body obtained by rotating the half cross section shown in FIG. The surface on the + Z side of the light distribution control member 2 is an emission surface 21 and is a plane parallel to the XY plane.

  A region R1 in the vicinity of the optical axis O on the −Z side of the light distribution control member 2 is a plane parallel to the XY plane. In the region R2 on the outer peripheral side of the region R1 on the −Z side of the light distribution control member 2, a plurality of triangular protrusions (second protrusions) 22 from the Z-axis direction (optical axis O direction). When viewed, they are arranged concentrically. As shown in FIG. 6B, each protrusion 22 has a surface 22a on the side close to the optical axis O and a surface 22b on the side far from the optical axis O, and the light incident on the surface 22b is the surface 22b. The angle of the surface 22b depends on the incident angle of each ray of the incident light beam on the surface 22b and the desired emission angle set for the light beam so that the exit surface 21 exits as it is after being refracted at Is set. The state of light rays incident on the regions R1 and R2 is shown in FIG.

  As shown in FIGS. 5 and 6, in the region R3 on the outer peripheral side of the region R2 on the −Z side of the light distribution control member 2, a plurality of quadrangular ridges (first ridges) 23 are formed. When viewed from the Z-axis direction (optical axis O direction), they are arranged concentrically in parallel. Each ridge portion 23 rises from the base portion of the ridge portion 23 on the side close to the optical axis O, and second surface rises from the base portion of the ridge portion 23 on the side far from the optical axis. 23b and a third surface 23c on the distal end side that connects between the first and second surfaces 23a, 23b. In the present embodiment, the first surface 23a is a straight line in the cross section including the optical axis O. However, since the first surface 23a is not an optically effective surface, the first surface 23a may be curved.

  Most or all of the partial light beams that have reached the third surface 23c of each ridge portion 23 out of the incident light beam having the divergence angle θin are within the ridge portion 23 from the third surface 23c of the ridge portion 23. Of the second and third surfaces 23b and 23c so as to become a partial light beam that forms a part of the emitted light beam at the irradiation angle θout after being reflected by the second surface 23b of the ridge 23 after entering The angle in the cross section including the optical axis O is set.

Such angle setting will be described with reference to FIG. Now, as shown in FIG. 8, in one ridge 23, the light enters from the surface 23 c at an angle θ ₁ from the LED ₁ with respect to the Z-axis direction, and enters the ridge 23 and then reflects on the surface 23 b. Then, consider the light beam emitted from the emission surface 21. Here, as shown in FIG. 8, the angle that the surface 23c makes with the Z-axis direction is A, the angle that the surface 23b makes with the Z-axis direction is B, and the angle that the surface 23a makes with the Z-axis direction. C, the angle formed by the light emitted from the emission surface 21 with respect to the Z-axis direction is θ ₂ , the refractive index of the material of the light distribution control member 2 is n, and the light travels from the air to the light distribution control member 2 After the critical angle is θ ₃ , the angle formed by the light traveling direction from the surface 23c to the surface 23b after reaching the surface 23b with respect to the Z-axis direction is θ ₄ , and after being totally reflected by the surface 23b An angle formed by the traveling direction of the light beam reaching the emission surface 21 with respect to the Z-axis direction is θ ₅ .

Then, in order beam enters incident from the surface 23c at an angle theta ₁ with respect to the Z-axis direction to the convex portion 23, the angle A, must satisfy Equation 1 below.

In addition, in order for the light beam to be emitted from the emission surface 21 at an angle θ ₃ after being reflected by the surface 23b, the angle B must satisfy the following formula 2 or the following formula 3. Note that Equations 2 and 3 are actually the same conditions.

Here, the critical angle θ ₃ is expressed by the following formula 4, the angle θ ₄ is expressed by the following formula 5, and the angle θ ₅ is expressed by the following formula 6.

Therefore, with respect to each ridge 23, the angle A, the number A, the number A, the number A, and the number A of the incident partial light beams incident on the surface 23c of the ridge 23 are such that B may be set. At this time, the angle θ2 may be an angle previously associated with the angle θ1. For example, the angle θ ₂ = θ ₁ · θout / θin. Further, when the light distribution control member 2 is manufactured by resin molding, the angles A and B are determined in consideration of ease of resin molding and the like. The angle C may be determined in consideration of ease of resin molding.

  And in this Embodiment, the light distribution control member 2 is the Z-axis direction (light) of the corner | angular part (ridgeline) 23d between the surfaces 23b and 23c of the convex part 23 in area | region R3 in the cross section containing the optical axis O. Compared with the case where all the positions in the direction of the axis O) are the same, at least one of the ridges 23 in the region R3 so that the utilization efficiency of the incident light beam with the divergence angle θin with respect to the outgoing light beam with the irradiation angle θout is increased. The positions in the Z-axis direction of the corners 23d of the two ridges 23 are different from the positions in the Z-axis direction of the corners 23d of the other at least one of the ridges 23 in the region R3. Is set to

  Here, FIG. 9 shows an example in which stray light is reduced and the utilization efficiency of the incident light flux is increased by changing the Z-axis direction position of the corner 23d of the ridge 23. FIG. 9A shows light rays when the positions of the corners 23d of the four ridges 23 are different from each other in the Z-axis direction and the line L1 connecting these corners 23d is inclined with respect to the X-axis direction. . FIG. 9B shows light rays when the positions of the corners 23d of the four ridges 23 are the same in the Z-axis direction and the line L2 connecting these corners 23d is parallel to the X-axis direction. . 9 (a) and 9 (b), the XZ coordinate position of the corner 23d of the rightmost ridge 23 is the same, and the position and direction of each incident light beam with this position as the reference are the same, Corresponding ridges 23 have the same angles A, B and C, the left three ridges 23 have the same corners 23d in the X-axis direction, and the left three ridges 23 have corners. The position of the Z-axis direction of the part was changed.

  In FIG. 9A, the four incident light beams do not become stray light but become an effective outgoing light beam, and the utilization efficiency of the incident light beam is high. On the other hand, in FIG. 9B, two incident light beams become stray light and do not become an effective outgoing light beam, and the utilization efficiency of the incident light beam is low.

  From FIG. 9, it can be seen that the utilization efficiency of the incident light beam can be improved by appropriately changing the Z-axis direction position of the corner 23d of the ridge 23 in the region R3. This was supported by simulation results described later.

  Specifically, for example, the number of ridges 23 and the like is substantially determined according to the divergence angle θin of the incident light beam, and the light rays obtained by the simulation according to the angle of the incident partial light beam and the angle of the output partial light beam that the ridge part 23 takes care of. While performing tracking or the like, the Z-axis direction positions of the angles A, B, C and the corner portion 23d may be determined in order from the protruding strip portion 23 on the side farther from the optical axis so as to reduce stray light. In addition, about the design method of the protruding item | line part 24 in area | region R2, it became impossible to use the protruding item | line part 23 appropriately (that is, if the protruding item | line part 23 is used, even if it changes angle A and B, stray light will increase. It is only necessary to determine the stray light so as to reduce the angle of the surfaces 22a and 22b while performing ray tracing by simulation and the like. Of the ridge 22 in the region R1

  1, 5 and 6 show the light distribution control member according to the first design example designed by the above-described method when the divergence angle θin of the incident light beam is 120 ° and the irradiation angle θout of the emitted light beam is 5 °. 2 is shown. As can be seen from FIGS. 5 and 6, in the light distribution control member 2 according to the first design example, the positions in the Z-axis direction of the corners 23d of the ridges 23 in the region R3 are not the same. The light distribution control member 2 according to the first design example is a light distribution control plate according to an embodiment of the present invention.

  With respect to the light distribution control member 2 according to the first design example, the Z-axis direction positions of the corner portions 23d of the ridge portions 23 in the region R3 are all made the same, and the other points are the first. A light distribution control member identical to the light distribution control member 2 according to the design example was designed as a comparative example. This light distribution control member is referred to as a light distribution control member according to the first comparative design example.

  10 and 11 show the light distribution control member 2 according to the second design example designed by the above-described method when the divergence angle θin of the incident light beam is 120 ° and the irradiation angle θout of the emitted light beam is 70 °. Is shown. FIG. 10 is a cross-sectional view showing the light distribution control member 2 according to the second design example. FIG. 11 is a half sectional view of the light distribution control member 2 shown in FIG. 10 and 11, elements that are the same as or correspond to those in FIGS. 5 and 6 are given the same reference numerals, and redundant descriptions thereof are omitted. As can be seen from FIGS. 10 and 11, in the light distribution control member 2 according to the second design example, the positions in the Z-axis direction of the corners 23d of the ridges 23 in the region R3 are not the same. The light distribution control member 2 according to the second design example is a light distribution control plate according to another embodiment of the present invention.

  Furthermore, with respect to the light distribution control member 2 according to the second design example, all the positions in the Z-axis direction of the corners 23d of the ridges 23 in the region R3 are changed to be the same. A light distribution control member identical to the light distribution control member 2 according to the design example 2 was designed as a comparative example. This light distribution control member is referred to as a light distribution control member according to the second comparative design example.

  With respect to the first and second design examples and the first and second comparative design examples, ray tracing is performed by simulation, and on a straight line 50 cm away from the light distribution control member in the + Z axis direction and parallel to the X axis. The illuminance distribution was obtained. At this time, the LED 1 has the directivity characteristics shown in FIG. 12, and the illuminance distribution on a straight line parallel to the X axis that is the same distance from the LED 1 in the + Z axis direction when the light distribution control member is not provided is shown in FIG. It was assumed to have the characteristics as shown. The simulation results are shown in FIGS.

  14 to 16 show simulation results of the light distribution control member 2 according to the first design example (θout = 5 °, the position of the corner portion 23d of the ridge 23 has a change in the Z-axis direction). FIG. 14 shows the result of ray tracing, FIG. 15 is an enlarged view around the portion E in FIG. 14, and FIG. 16 shows the illuminance distribution.

  FIGS. 17 and 18 show the simulation results of the light distribution control member according to the first comparative design example (θout = 5 °, no change in the Z-axis direction position of the corner 23d of the ridge 23). FIG. 17 shows the ray tracing result corresponding to FIG. 14, and FIG. 18 shows the illuminance distribution.

  Comparing FIG. 14 to FIG. 16 with FIG. 17 and FIG. 18, in the light distribution control member 2 according to the first design example in which the position in the Z-axis direction of the corner portion 23 d of the ridge portion 23 is changed, the ridge portion As compared with the light distribution control member according to the first comparative design example in which the position of the corner 23d of the 23 is not changed, it can be seen that the stray light is reduced and the effective emitted light quantity is increased.

  19 and 20 show simulation results of the light distribution control member 2 according to the second design example (θout = 70 °, the position of the corner 23d of the ridge 23 has a change in the Z-axis direction). FIG. 19 shows the result of ray tracing, and FIG. 20 shows the illuminance distribution.

  FIG. 21 shows a simulation result of the light distribution control member according to the second comparative design example (θout = 70 °, no change in the Z-axis direction position of the corner 23d of the ridge 23). FIG. 21 shows the illuminance distribution.

  Comparing FIG. 19 to FIG. 20 with FIG. 21, in the light distribution control member 2 according to the second design example in which the position in the Z-axis direction of the corner 23 d of the ridge 23 changes, the corner of the ridge 23 It can be seen that the stray light is reduced and the effective amount of emitted light is increased as compared with the light distribution control member according to the second comparative design example in which the position of the portion 23d in the Z-axis direction is not changed.

  According to the present embodiment, the use efficiency of light is increased for the same reason as the inner lens disclosed in Patent Document 1 due to the provision of the ridges 23. And according to this Embodiment, unlike the inner lens currently disclosed by the said patent document 1, since the Z-axis direction position of the corner | angular part 23d of the protruding item | line part 23 is changed, the corner | angular part of the protruding item | line part 23 is changed. Compared with the case where all the positions in the Z-axis direction of the portion 23d are the same, the light use efficiency is further increased.

  While the embodiments and examples of the present invention have been described above, the present invention is not limited to these embodiments and examples.

  For example, in the present invention, the structure of the holder 3 is not limited to the structure described above, and the light source is not limited to the power LED, and an arbitrary light source may be used.

  The light distribution control member according to the present invention may be a so-called linear type light distribution control member having a three-dimensional shape obtained by moving the cross-sectional shape shown in FIGS. 5 and 10 in the Y-axis direction. For such a linear light distribution control member, a linear light source extending in the Y-axis direction may be used.

  Moreover, in the said embodiment, although the output surface 21 of the light distribution control member 2 became a plane parallel to XY plane, in this invention, this output surface 21 is good also as convex surfaces and concave surfaces, such as a spherical surface.

It is sectional drawing which shows the irradiation apparatus by one embodiment of this invention. It is a disassembled perspective view of the irradiation apparatus shown in FIG. It is the perspective view which looked at the holder main body in FIG.1 and FIG.2 from the lower side. It is a perspective view which shows the fitting state of LED in FIG. 1, and a holder main body. It is sectional drawing which shows the example of a design of the light distribution control member in FIG. It is the figure which expanded a part of light distribution control member shown in FIG. It is a figure which shows the mode of the light ray which injects into the predetermined area | region of a light distribution control member. It is explanatory drawing for demonstrating the setting method of an angle. It is a figure which shows the example of a mode that the utilization efficiency of light increases by changing the optical axis direction position of the corner | angular part of the protruding item | line part. It is sectional drawing which shows the other example of a design of a light distribution control member. FIG. 11 is a half sectional view of the light distribution control member shown in FIG. 10. It is a directivity characteristic figure of LED. It is a figure which shows the illumination intensity distribution by LED when not using a light distribution control member. It is a figure which shows the ray tracing result of the light distribution control member by a 1st design example. It is an enlarged view of the E part vicinity in FIG. It is a figure which shows the illumination intensity distribution of the light distribution control member by a 1st design example. It is a figure which shows the ray tracing result of the light distribution control member by a 1st comparative design example. It is a figure which shows the illumination intensity distribution of the light distribution control member by the 1st comparative design example. It is a figure which shows the light trace result of the light distribution control member by a 2nd design example. It is a figure which shows the illumination intensity distribution of the light distribution control member by a 2nd design example. It is a figure which shows the illumination intensity distribution of the light distribution control member by the 2nd comparative design example.

Explanation of symbols

1 Power LED (light source)
2 Light distribution control member 3 Holder 15 Communication path 21 Outgoing surface 22 2nd convex strip part 23 1st convex strip part 23a 1st surface 23b 2nd surface 23c 3rd surface

Claims (12)

A light distribution control member made of a translucent material that emits an incident light beam having a predetermined divergence angle in a predetermined cross section including an optical axis as an output light beam having an irradiation angle smaller than the divergence angle in the predetermined cross section;
Provided with a plurality of first ridges on the incident side of the incident light flux,
The plurality of first ridges are parallel to each other in a plan view as viewed from the optical axis direction,
Each of the first ridges includes a first surface rising from the base of the first ridge on the side close to the optical axis, and a base of the first ridge on the side far from the optical axis. A second surface rising from the first surface and a third surface on the front end side connecting between the first and second surfaces;
Most or all of the partial light fluxes that have reached the third surface of each of the first ridges of the incident light flux are transferred from the third surface of the first ridges to the first surface. After entering the ridge portion, after being reflected by the second surface of the first ridge portion, the first ridge portion of the first ridge portion so as to be a partial light beam that forms a part of the emitted light beam. An angle in the predetermined cross section of the second and third surfaces is set,
Compared with the case where the positions in the optical axis direction of the corners between the second and third surfaces of the plurality of first ridges in the predetermined cross section are all the same, the incidence on the emitted light flux The position in the optical axis direction of the corner in the predetermined cross section of at least one of the plurality of first ridges is set to the plurality of first ridges so that the use efficiency of the light flux is increased. A light distribution control member, which is set to be different from a position in the optical axis direction of the corner in the predetermined cross section of at least one other ridge of the ridge.   2. The light distribution control member according to claim 1, wherein the plurality of first protrusions are arranged concentrically around the optical axis in a plan view as viewed from the optical axis direction.   2. The light distribution according to claim 1, wherein the plurality of first protrusions are arranged so as to extend linearly in a direction orthogonal to the predetermined cross section in a plan view as viewed from the optical axis direction. Control member. On the incident side of the incident light beam, a second ridge portion having a triangular shape in the cross section is provided,
The second ridges are aligned with the plurality of first ridges in a plan view as viewed from the optical axis direction, and closer to the optical axis than the plurality of first ridges. The light distribution control member according to any one of claims 1 to 3, wherein the light distribution control member is arranged so as to be positioned at a position.   The light distribution control member according to any one of claims 1 to 4, wherein at least an emission region of the emitted light beam on a surface on an emission side of the emitted light beam forms a flat surface. (
5. The light distribution control member according to claim 1, wherein at least an exit region of the outgoing light beam on a surface on the outgoing side of the outgoing light beam has a convex curved surface or a concave curved surface.   An irradiation apparatus comprising: the light distribution control member according to claim 1; and a light source that emits light that becomes the incident light beam. The light source has a rectangular parallelepiped outer shape and emits light from one surface side,
A holder for holding the light distribution control member on the one surface of the light source with a gap;
The holder has a cylindrical inner surface;
8. The cylindrical inner surface is fitted in substantially linear contact with only four sides between four side surfaces when the one surface of the light source is the upper surface. The irradiation apparatus as described. A light distribution control member made of a translucent material that emits an incident light flux as an outgoing light flux having a different light distribution;
A light source having a rectangular parallelepiped shape and emitting light that becomes the incident light beam from one surface side;
A holder for holding the light distribution control member at an interval on the one surface of the light source;
With
The holder has a cylindrical inner surface;
The irradiation apparatus characterized in that the cylindrical inner surface is fitted in substantially linear contact with only four sides between four side surfaces when the one surface of the light source is the upper surface.   The irradiation apparatus according to claim 8 or 9, wherein a communication path is formed in the holder for communicating a space near the four side surfaces to the outside of the side.   The irradiation apparatus according to claim 8, wherein the light source is a surface-mounted light-emitting device mounted on a circuit board.   The irradiation apparatus according to claim 8, wherein the light source is an LED.

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