JP2012168501A - Luminous flux control member, optical device equipped therewith, and luminous flux shaping method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a luminous flux control member capable of easily and securely obtaining desired light distribution characteristics and also achieving diversification in the obtained light distribution characteristic and improvement in versatility accompanying that, an optical device equipped therewith, and a luminous flux shaping method.SOLUTION: An incidence area 2 shapes light emitted from a light source 4 into light having first light distribution characteristics showing a maximum value of light intensity in predetermined two directions symmetrical based upon an optical axis on an arbitrary virtual plane including the whole optical axis, and an emission area 3 shapes the light shaped by the incidence area 2 and having the first light distribution characteristics into light having second light distribution characteristics as the desired light distribution characteristics.

Description

  The present invention relates to a light beam control member, an optical device including the light beam control member, and a light beam shaping method, and more particularly to shaping light emitted from a light source into light having desired light distribution characteristics and irradiating an irradiated surface. The present invention relates to a suitable light flux controlling member, an optical device including the same, and a light flux shaping method.

  2. Description of the Related Art Conventionally, as a light flux control member suitable for thinning and lightening, a cross-sectional saw blade shape (hereinafter referred to as Fresnel shape) in which a light incident region is divided into a plurality of concentric annular (annular) regions. A light beam control member (so-called Fresnel lens) is known, and this type of light beam control member has been used for applications in which thinning is particularly advantageous (for example, loupes, illumination systems) (for example, Patent Document 1). reference).

  When this type of light flux control member is incorporated into a product for lighting applications, a light source (light emitting element) such as an LED (Light Emitting Diode) is emitted from the light source on the incident area side formed in the Fresnel shape. The light beam (light beam) is fixed after being aligned so that the central axis (center light) of the light (light beam) is coaxial with the optical axis of the light beam control member.

  In addition, the Fresnel shape of this type of light flux controlling member includes a type having only a refracting surface that refracts light emitted from a light source, and a type having a reflecting surface as well as a refracting surface. However, the latter is more advantageous than the former in efficiently using the light emitted from the light source.

  Specifically, an LED as an example of a light source emits light with a wide divergence angle having a light distribution characteristic according to a so-called Lambertian distribution, and this light is efficiently used for illumination or the like. In order to use it, there is a market demand to increase the directivity by converging the light to the optical axis side by the light flux controlling member. Therefore, in order to converge the light emitted from the LED, when the Fresnel shape having only the refractive surface is used, the amount of change in the traveling direction of the light in the incident region of the light flux controlling member is determined only by refraction by the refractive surface. The traveling direction of the light propagating through the light flux controlling member with respect to the traveling direction of light (original traveling direction) at the time of entering the light flux controlling member does not show a great change. For this reason, in particular, the light emitted toward the wide-angle side from the LED cannot be directed toward the irradiated surface side by refraction, and the entire light (light flux) cannot be sufficiently converged. On the other hand, in the Fresnel shape provided with the reflecting surface, the light incident on the light flux controlling member from the refracting surface can be reflected by the total reflecting surface, and the traveling direction can be greatly changed. Also, the emitted light can be directed toward the irradiated surface side. Thereby, it was sufficiently possible to shape the light emitted from the LED into light having a light distribution characteristic in which the half-value width of the light intensity (luminance) is 30 ° to 50 °, for example.

JP 2007-134316 A

  However, in the past, the light distribution characteristic obtained by the light flux controlling member was largely dependent on the Fresnel shape of the incident region, so it may be difficult to achieve this depending on the light distribution characteristic to be obtained. There was a problem. For example, when trying to obtain a light distribution characteristic with a half-value width of about 20 °, it is difficult to realize this with only the Fresnel shape, even when a Fresnel shape having a reflecting surface is used.

  That is, the half-value angle of the light having the light distribution characteristic according to the Lambertian distribution emitted from the LED is 60 °, and the light that originally exists within the range of 20 ° from the optical axis (in other words, the total luminous flux) For example, the central side light that does not require convergence by the light flux controlling member is about 12% of the total. For this reason, it is necessary to obtain a light distribution characteristic with a half-value angle of 20 ° by condensing most of the remaining light emitted from the optical axis at an angle larger than 20 ° by the light flux controlling member. At this time, if the light emitted from the LED almost right side (substantially perpendicular to the optical axis direction) is collected within a range of 20 ° from the optical axis, the traveling direction must be changed by nearly 70 °. However, when such an optical path of light is formed, the size and angle of the protrusions constituting the Fresnel shape are unreasonable for manufacturing, and as a result, a light distribution characteristic with a half-value width of 20 ° is realized. It was difficult to form the Fresnel shape as designed. Specifically, when the light flux controlling member is resin-molded using a mold, the sharp Fresnel shape for realizing a half-value width of 20 ° is difficult to manufacture the mold, and injection molding. Insufficient filling of the projection material with the resin material may occur, or release from the mold may become difficult.

  Such a problem is not limited to the light distribution characteristic having a half-value width of 20 °, but has a regularity in the distribution of the light intensity in order to obtain the desired light distribution characteristic (usually, an irradiation light pattern having a shape or brightness according to the application). This is a problem that can occur in the same manner when the formation of the (saturated) is to be largely dependent on the Fresnel shape of the incident region.

  Further, conventionally, since the Fresnel shape functions to converge the light of the LED to the optical axis (0 °) side, restrictions are imposed on variations in the light distribution characteristics obtained in the emission region, and this is useful for applications. There has also been a problem that it is difficult to ensure the degree of freedom of the corresponding light beam shaping.

  Therefore, the present invention has been made in view of such problems, and it is possible to easily and surely obtain a desired light distribution characteristic, as well as diversification of the obtained light distribution characteristic and versatility associated therewith. It is an object of the present invention to provide a light beam control member that can be improved, an optical device including the same, and a light beam shaping method.

  In order to achieve the above-described object, a feature of the light flux controlling member according to claim 1 of the present invention is that an incident area where light emitted from a light source is incident and a position opposite to the incident area in the optical axis direction. And an emission region for emitting the light incident on the incident region toward the irradiated surface side, and shaping the light emitted from the light source into light having a desired light distribution characteristic. A light flux controlling member for irradiating a surface, wherein the incident region has a concentric ring shape centered on the optical axis when viewed from the light source side, and is cut at an arbitrary virtual plane including the entire optical axis A plurality of protrusions that are adjacent to each other in the radial direction such that the cross-section has a saw-tooth shape, and the protrusion includes an incident part that receives light emitted from the light source and refracts the incident light. The optical axis with respect to this incident part A quasi-reflecting portion that is formed at the outer position in the radial direction, and totally reflects the light incident on the incident portion toward the emission region, and the incident region is light emitted from the light source. Is shaped into light having a first light distribution characteristic showing the maximum value of light intensity in two predetermined directions symmetric with respect to the optical axis on the virtual plane, and the emission region is the incident region The light having the first light distribution characteristic shaped by the above is shaped into light having the second light distribution characteristic which is a desired light distribution characteristic.

  According to the first aspect of the present invention, based on the light distribution characteristic of the light source, the first light distribution having peak intensities in two predetermined directions on the wide angle side from the optical axis direction (0 °). After forming the characteristics, by forming the desired light distribution characteristics (second light distribution characteristics) based on the first light distribution characteristics, the formation of the desired light distribution characteristics can be performed in each protrusion of the incident region. Compared to a case where the projection is largely dependent on, the light flux controlling member as designed can be manufactured by reducing the burden on the shape of each protrusion, so that desired light distribution characteristics can be obtained easily and reliably. . Further, by shaping the light having the first light distribution characteristic in the incident region, the light finally having the peak intensity in the optical axis direction as in the conventional Fresnel shape is finally formed in the emission region. The aspect of the desired light distribution characteristic to be obtained can be increased.

  Further, the light beam control member according to claim 2 is characterized in that, in claim 1, the emission region is formed in a conical surface shape convex to the irradiated surface side with the optical axis as a symmetry axis, The second light distribution characteristic having a circular shape that is rotationally symmetric with respect to the optical axis is obtained.

  According to the second aspect of the present invention, when a perfect circular light distribution characteristic having a narrow half-value width suitable for a projector or the like is desired, this can be easily and reliably obtained.

  Further, the light beam control member according to claim 3 is characterized in that, in claim 1, the exit region is two regions having a central angle of 180 ° around the optical axis when viewed in plan from the irradiated surface side. And is formed so as to exhibit a concave V-shape on the light source side in the optical axis direction when viewed from the extending direction of the boundary line between the two regions, and is emitted from the light flux controlling member The second light distribution characteristic is obtained such that the irradiation range on the irradiated surface becomes an ellipse.

  And according to this invention concerning Claim 3, it is suitable for the use etc. which irradiate light from the diagonal direction with respect to to-be-irradiated surfaces, such as a street light, and form a perfect circle irradiation spot on an to-be-irradiated surface When the elliptical light distribution characteristic is desired, this can be obtained easily and reliably.

  Still further, the light flux controlling member according to claim 4 is characterized in that, in claim 1, the emission region further includes eight light emitting areas having a central angle of 45 ° around the optical axis when viewed in plan from the irradiated surface side. Four of the eight boundary lines that are divided into regions and formed between each of the eight regions and the adjacent region are the light flux control from the optical axis side toward the outer edge side of the light flux control member. As the ridgeline that gradually increases the thickness of the member is formed around every other optical axis, the remaining four of the eight boundary lines are formed in the valleys between the adjacent regions, The second light distribution characteristic is obtained such that the irradiation range of the emitted light from the light flux controlling member on the irradiated surface is rectangular.

  According to the fourth aspect of the present invention, when a rectangular light distribution characteristic suitable for the purpose of illuminating a specific rectangular area such as a camera flash is desired, this can be obtained easily and reliably.

  In addition, the light flux controlling member according to claim 5 is characterized in that an incident area where light emitted from a light source is incident and light incident on the incident area that is located on the opposite side of the incident area in the optical axis direction. Is incident internally, and the anti-incident region that totally reflects the light whose incident angle is larger than the critical angle out of the incident light toward the outer side in the radial direction, and the outer side in the radial direction with respect to the anti-incident region And an emission region that emits the light totally reflected by the counter-incidence region toward the outside in the radial direction, and shapes the light emitted from the light source into light having a desired light distribution characteristic The incident region has a concentric annular shape centered on the optical axis when viewed in plan from the light source side, and a cross section cut along an arbitrary virtual plane including the entire optical axis. In the radial direction to present a saw-tooth shape A plurality of protrusions adjacent to each other, wherein the protrusions are incident with light emitted from the light source, refracting the incident light, and the optical axis as a reference with respect to the incident part. And a total reflection part that totally reflects the light incident on the incident part toward the anti-incident area, and the incident area is light emitted from the light source. Is shaped into light having a first light distribution characteristic showing the maximum value of light intensity in two predetermined directions symmetric with respect to the optical axis on the virtual plane, and the emission region is the incident region The light having the first light distribution characteristic shaped by the above is shaped into light having the second light distribution characteristic which is a desired light distribution characteristic.

  According to the fifth aspect of the invention, as in the first aspect, the desired light distribution characteristic can be obtained simply and reliably, and the desired light distribution characteristic finally obtained in the emission region can be obtained. Aspects can be increased.

  Furthermore, the optical device according to a sixth aspect is characterized in that the optical device includes a light source that emits light and the light flux controlling member according to any one of the first to fifth aspects.

  According to the sixth aspect of the present invention, desired light distribution characteristics can be reliably obtained with an easy-to-manufacture configuration, and a perfect circular light distribution characteristic, an elliptical light distribution characteristic, a rectangular light distribution characteristic, and a light source directly above. It is possible to realize diversification of obtained light distribution characteristics such as predetermined light distribution characteristics such that the luminance distribution spreads outward in the radial direction while suppressing the luminance in the vicinity.

  Furthermore, the light shaping method according to claim 7 is characterized in that light emitted from a light source is incident on an incident area of a light flux controlling member and emitted from the light emitting area of the light flux controlling member toward the irradiated surface side. In this case, a light beam shaping method for shaping the light into light having a desired light distribution characteristic, wherein the incident region as the light beam control member is centered on the optical axis when viewed in plan from the light source side. A plurality of protrusions that are adjacent to each other in a radial direction such that a cross-section cut along an arbitrary virtual plane including the entire optical axis has a saw-blade shape. The light emitted from the incident light is incident on the incident portion that refracts the incident light, and the light incident on the incident portion with respect to the incident portion. Toward the exit area And a light intensity maximum in two predetermined directions symmetric with respect to the optical axis on the virtual plane. Then, the light having the first light distribution characteristic is shaped into the light having the first light distribution characteristic, and then the light having the first light distribution characteristic is converted into the second light distribution characteristic as a desired light distribution characteristic in the emission region. It is characterized by shaping into light that it has.

  According to the seventh aspect of the present invention, the light emitted from the light source can be easily converted into light having various desired light distribution characteristics such as a perfect circular light distribution characteristic, an elliptical light distribution characteristic, or a rectangular light distribution characteristic. And it can be shaped reliably.

  The light shaping method according to claim 8 is characterized in that the light emitted from the light source is incident on the incident area of the light flux controlling member and totally reflected radially outward in the anti-incident area of the light flux controlling member. A light beam shaping method for shaping the light into light having a desired light distribution characteristic when the light beam is emitted from the emission region of the light flux control member toward the outside in the radial direction, and as the light flux control member, The incident area has a concentric ring shape centered on the optical axis when viewed from the light source side, and the section cut along an arbitrary virtual plane including the entire optical axis has a saw-tooth shape. A plurality of protrusions adjacent to each other in the radial direction, wherein the protrusions receive light emitted from the light source and refract the incident light; and the optical axis with respect to the incident part The diameter based on And a total reflection part that totally reflects the light incident on the incident part toward the anti-incident area, and the light emitted from the light source is incident on the incident area. The light is shaped into light having a first light distribution characteristic showing a maximum value of light intensity in two predetermined directions symmetric with respect to the optical axis on the virtual plane, and the first region has the first light distribution characteristic. The light having the light distribution characteristic is shaped into light having the second light distribution characteristic as the desired light distribution characteristic.

  According to the eighth aspect of the present invention, the light emitted from the light source is easily converted into light having a predetermined light distribution characteristic such that the luminance distribution spreads outward in the radial direction while suppressing the luminance near the light source. And it can be shaped reliably.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to obtain a desired light distribution characteristic simply and reliably, the diversification of the obtained light distribution characteristic and the versatility accompanying this can be aimed at.

1 is a schematic configuration diagram showing a first embodiment of a light flux controlling member and an optical apparatus including the same according to the present invention. 1 is a bottom view of the light flux controlling member of FIG. AA sectional view of FIG. 3 is an enlarged view of the main part of the optical device including the partially enlarged view of FIG. Light intensity distribution diagram of first light distribution characteristic having optical path on virtual plane including optical axis Illuminance distribution diagram when a light beam having the first light distribution characteristic is irradiated on a virtual plane orthogonal to the optical axis A composite coordinate system for explaining the positional relationship between the light intensity distribution of FIG. 5, the optical axis, and the virtual plane from which the illuminance distribution of FIG. 6 is obtained. The front view which shows the light beam control member of Example 1 Plan view of FIG. AA sectional view of FIG. Light intensity distribution diagram of second light distribution characteristic in Example 1 having optical path on virtual plane including optical axis Illuminance distribution diagram when the light beam having the second light distribution characteristic in the first embodiment is irradiated on a virtual plane orthogonal to the optical axis The front view which shows the light beam control member of Example 2 Plan view of FIG. AA sectional view of FIG. Light intensity distribution diagram of second light distribution characteristic in Example 2 having optical path on virtual plane including optical axis Illuminance distribution diagram when the light beam having the second light distribution characteristic in the second embodiment is irradiated onto a virtual plane orthogonal to the optical axis The perspective view which shows the light beam control member of Example 3. The front view which shows the light beam control member of Example 3 Plan view of FIG. AA sectional view of FIG. Light intensity distribution diagram of second light distribution characteristic in Example 3 having optical path on virtual plane including optical axis Illuminance distribution diagram when the light beam having the second light distribution characteristic in the third embodiment is irradiated on a virtual plane orthogonal to the optical axis The schematic block diagram which shows 2nd Embodiment of the light beam control member which concerns on this invention, and an optical apparatus provided with the same The top view of the light beam control member of FIG. 24 is a bottom view of the light flux controlling member in FIG. AA sectional view of FIG. Light intensity distribution diagram of the first light distribution characteristic in the second embodiment having an optical path on a virtual plane including the optical axis Light intensity distribution diagram of second light distribution characteristics in the second embodiment having an optical path on a virtual plane including the optical axis Schematic configuration diagram showing a modification of the second embodiment Plan view of the light flux controlling member of FIG. 30 is a bottom view of the light flux controlling member in FIG. AA sectional view of FIG.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

  Here, FIG. 1 is a schematic configuration diagram illustrating a light flux controlling member and an optical apparatus including the same according to the present embodiment. FIG. 2 is a bottom view of the light flux controlling member of FIG. 3 is a cross-sectional view taken along the line AA in FIG. FIG. 4 is an enlarged view of a main part of the optical device including the partially enlarged view of FIG.

  As shown in FIG. 1, the light flux controlling member 1 in the present embodiment has a disk-shaped member body 1a having a predetermined thickness in the direction of the optical axis OA. The member body 1a is formed by, for example, an injection molding method using a transparent resin material such as PMMA (polymethyl methacrylate), PC (polycarbonate), COP (cycloolefin resin), EP (epoxy resin), or silicone resin. It can be formed using a mold.

  Further, as shown in FIGS. 1 and 2, an incident region that has a circular outer shape concentric with the optical axis OA in the bottom view is formed on one end surface (downward in FIG. 1) in the optical axis OA direction of the member main body 1 a 2 is formed.

  Furthermore, as shown in FIG. 1, the other end surface (upper side in FIG. 1) of the member main body 1a opposite to the incident area 2 in the optical axis OA direction is concentric with the optical axis OA in the plan view and is incident area 2 An emission region 3 having a circular outer shape with the same diameter as that of the first and second electrodes is formed. As will be described later, since the emission region 3 can take various specific shapes according to the concept, in FIG. 1 and FIG. Yes.

  Furthermore, as shown in FIGS. 1 and 4, a light source 4 such as an LED is disposed at a position facing the incident region 2 with a predetermined interval in the optical axis OA direction. The optical device 5 is configured together with the light flux controlling member 1. As shown in FIG. 4, the light source 4 emits light (light beam) L having a predetermined divergence angle with respect to the optical axis OA direction toward the light beam control member 1 side. The center axis (center light) of the light L coincides with the optical axis OA of the light flux controlling member 1. In FIG. 4, only the optical path of the light L emitted from one light emitting point on the optical axis OA in the light source 4 is shown, but actually, the entire light source 4 performs surface light emission. It has become. The light L emitted from the light source 4 in this way enters the incident region 2 and then travels on the optical path inside the member main body 1a.

  On the other hand, the light L of the light source 4 that has entered the incident region 2 and traveled inside the member main body 1a enters the emission region 3 from inside the member main body 1a (internal incidence). The internally incident light L is emitted from the emission region 3 to the irradiated surface side.

  Next, the incident area 2 will be described in more detail. As shown in FIGS. 2 and 4, the incident area 2 includes a circular central portion 6 concentric with the optical axis OA and a plurality of protrusions surrounding the central portion 6. Part 7.

  As shown in FIGS. 2 and 4, the plurality of protrusions 7 are adjacent to each other in the radial direction (lateral direction in FIG. 4) orthogonal to the optical axis OA direction.

  As shown in FIG. 2, each protrusion 7 has a concentric ring shape centered on the optical axis OA in the bottom view (when viewed in plan from the light source 4 side), and as shown in FIGS. 3 and 4. In addition, a cross section (longitudinal cross section) cut along an arbitrary virtual plane including the entire optical axis OA has a saw-tooth shape, and forms a Fresnel shape as a whole.

  Further, as shown in FIG. 4, each protrusion 7 is located at an outer position in the radial direction with respect to the incident surface 10 as the incident portion and the optical axis OA with respect to the incident surface 10 (inner end in the radial direction). And a total reflection surface 11 as a formed total reflection portion. Here, the incident surface 10 is formed in a cylindrical surface centered on the optical axis OA. On the other hand, the total reflection surface 11 has a predetermined acute inclination angle (taper angle) with respect to the optical axis OA that is inclined inward in the radial direction toward the light source 4 side (downward in FIG. 4) in the optical axis OA direction. Is formed on a tapered surface concentric with the optical axis OA. The incident surface 10 and the total reflection surface 11 are connected to each other at both tip portions (lower end portions in FIG. 4). Note that the inclination angle of the total reflection surface 11 is such that when the light flux controlling member 1 is resin-molded using a mold, the transfer surface of the tip portion of the protrusion 7 in the mold is not insufficiently filled with the resin material. It is desirable to set the inclination angle. Further, the incident surface 10 is not limited to the cylindrical surface, and light having a predetermined acute angle with respect to the optical axis OA that is inclined outward in the radial direction toward the light source 4 side in the optical axis OA direction. You may form in the taper surface concentric with axis | shaft OA. Further, both the incident surface 10 and the total reflection surface 11 may be formed by curved surfaces having inflection points in the cross section including the optical axis OA.

  Here, as illustrated in FIG. 4, the light L emitted from the light source 4 is incident on the incident surface 10, and the incident light L is incident on the total reflection surface 11 side by the incident surface 10. Refracted.

  On the other hand, as shown in FIG. 4, the light L of the light source 4 refracted by the incident surface 10 is internally incident on the total reflection surface 11 at an incident angle greater than the critical angle. Are totally reflected by the total reflection surface 11 toward the emission region 3 side, that is, the irradiated surface side.

  At this time, since the total reflection surface 11 is formed in a shape to be rotated with the optical axis OA as an axis of symmetry, a light beam having a rotational symmetry shape is emitted from the entire total reflection surface 11.

  In this embodiment, the light of the light source 4 traveling from the entire incident area 2 toward the emission area 3 side using the total reflection on the total reflection surface 11 in this way is shown in FIGS. It has a first light distribution characteristic as shown. However, the first light distribution characteristic indicates the maximum value of light intensity (in other words, luminous intensity) in two predetermined symmetric directions with respect to the optical axis OA on an arbitrary virtual plane including the entire optical axis OA. Such light distribution characteristics.

  Specifically, FIG. 5 shows, as the first light distribution characteristic, the distribution of the intensity (cd) of light after entering from the incident region 2 into the light flux controlling member 1 (that is, the distribution in the light flux controlling member 1). The simulation result of (optical characteristics) is represented as a graph on the XZ plane which is a virtual plane including the optical axis OA. In this XZ plane, the X direction is the radial direction of the light flux controlling member 1, and the Z direction is the optical axis OA direction. FIG. 6 shows the light distribution characteristics of FIG. 5 on the XY plane, which is a virtual plane orthogonal to the optical axis OA. The X direction of the XY plane is the same as that in FIG. 5, and the Y direction is taken in the radial direction of the light flux controlling member 1 orthogonal to the X direction. In FIG. 5, the angle 0 ° shown at the bottom end of the graph corresponds to the front (irradiation direction) in the direction of the optical axis OA. In FIG. 5, the center point (origin) of the graph indicates the intersection (light emission point) between the optical axis OA and the light emitting surface of the light source 4. Further, in the graph of FIG. 6, the origin is taken at a position 1 m away from the light source 4 on the optical axis OA (symbol H in FIG. 7), and the light intensity of the light irradiating the virtual plane (XY plane) is shown. Accordingly, the illuminance (color shading shown on the graph) varies. That is, the positional relationship between the light emission point of the light source 4 corresponding to the center point of the graph of FIG. 5, the optical axis OA, and the virtual plane from which the illuminance distribution of FIG. 6 is obtained is as shown in FIG. The first light distribution characteristic shown in FIG. 5 is that the luminous intensity (cd) of light incident on the light flux controlling member 1 on the XZ plane is −180 ° <θ ≦ 180 ° (the angle θ is the origin of the light source 4). FIG. 5 shows the result of measurement in the range of the angle (from the optical axis OA (Z-axis) in spherical coordinates), and the angle ψ in FIG. 7 is within 0 ° <ψ ≦ 360 °. A graph having almost the same shape as that of the object can be represented. That is, the first light distribution characteristic is approximately 360 ° rotationally symmetric about the optical axis OA. This is clear from the image of FIG.

  Here, as shown in FIG. 5, the first light distribution characteristic is that each direction (angle) near + 20 ° and −20 ° as two predetermined symmetric directions with respect to the optical axis OA as a reference (0 °). It can be seen that the intensity of the outgoing light from the incident region 2 shows the maximum value (peak intensity).

  Such a first light distribution characteristic is such that the distance on the optical axis OA from the light emitting surface of the light source 4 to the incident region 2 is set to 0.7 mm, and the light emitting surface size of the light source 4 is set to 0.75 mm × 0.75 mm. It is realized by setting in all directions.

  As described above, in the present embodiment, the light emitted from the light source 4 can be shaped into light having the first light distribution characteristic in the incident region 2.

  Then, the light having the first light distribution characteristic shaped in this way reaches the emission area 3 after being emitted from the incidence area 2 (internal incidence), and is desired according to the shape of the emission area 3 The light is shaped into light having the second light distribution characteristic.

  Further, the light having the second light distribution characteristic shaped in this way is emitted from the emission region 3 toward the irradiated surface side.

  According to such a configuration of the present embodiment, the first light distribution characteristic is formed based on the light distribution characteristic of the light source 4, and then the desired light distribution characteristic (the second light distribution characteristic based on the first light distribution characteristic). The desired light distribution characteristics are obtained by taking two steps, such as forming the light distribution characteristics of the incident light region 2 in comparison with the case where the formation of the light distribution characteristics of the entire light flux controlling member is entirely dependent on the incident area. It is possible to manufacture a light flux controlling member as designed (with few molding defects) by reducing the burden on the shape of each protrusion 7. Thereby, a desired light distribution characteristic can be obtained simply and reliably.

  Further, according to the present embodiment, by shaping the light having the first light distribution characteristic in the incident area 2, it becomes easier to perform the light beam shaping on the emission area 3 side than in the conventional case. The aspect of the desired light distribution characteristic finally obtained can be increased. That is, as in the prior art, the traveling direction of light (in other words, the light distribution characteristic) having directivity (in other words, peak intensity) in one direction (in the direction of the optical axis OA) by convergence in the Fresnel shape, The degree of freedom that can be changed and adjusted on the exit region 3 side is more limited than when the directivity is provided in two directions on the entrance region 2 side. This means that the mode of desired light distribution characteristics that can be obtained on the emission region 3 side is limited. However, when a desired light distribution characteristic is to be obtained on the exit region 3 side without considering any directivity on the entrance region 2 side, a significant burden (complexity) is imposed on the surface shape of the exit region 3. It will occur, and it will be difficult to realize from the viewpoint of manufacturing. On the other hand, when the light having directivity in two predetermined directions on the XZ plane in the incident region 2 is shaped as in the present embodiment, the traveling direction of the light is changed on the emission region 3 side. The degree of freedom of adjustment can be expanded, and the burden on the surface shape of the emission region 3 is not excessive. Therefore, according to the present embodiment, it is possible to realize desired light distribution characteristics in various modes according to applications.

  Specific modes of desired light distribution characteristics that can be obtained by the configuration of the present embodiment are as shown in the following Examples 1 to 3, for example.

  FIG. 8 is a front view showing the light flux controlling member 1 of the first embodiment. FIG. 9 is a plan view of FIG. 10 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIGS. 8 and 9, in this embodiment, the emission region 3 is formed in a simple conical surface shape convex toward the irradiated surface side (upper side in FIG. 8) with the optical axis OA as the axis of symmetry. ing.

  Other configurations and operations are the same as those described with reference to FIGS.

  According to the light flux controlling member 1 of this embodiment, a perfect circular light distribution characteristic (second light distribution characteristic) having regularity as shown in FIGS. 11 and 12 (second light distribution characteristic) It is possible to reliably obtain a circular light distribution characteristic that is rotationally symmetric with respect to the optical axis OA. Here, in FIG. 11, as the light distribution characteristic of the light flux controlling member 1 in the present embodiment, the simulation result of the distribution (that is, the light distribution characteristic) of the intensity (cd) of the emitted light from the emission region 3 is shown in the XZ plane. It is represented as the graph above. FIG. 12 shows the light distribution characteristics of FIG. 11 as a graph on the XY plane. In FIG. 11, the angle 0 ° shown at the lowermost end of the graph corresponds to the front in the direction of the optical axis OA, as in FIG. In FIG. 11, the center point (origin) of the graph indicates the intersection of the optical axis OA and the emission region 3, and the line segment extending from the center point in the direction of 0 ° is the same as in FIG. 5. This is a line segment assumed on the same straight line as the optical axis OA.

  Here, as shown in FIG. 11, the light distribution characteristic in the present embodiment is a light distribution characteristic in which the half-value width is suppressed to about 20 °, and such a light distribution characteristic is suitable for the use of a projector or the like. is there.

  FIG. 13 is a front view showing the light flux controlling member 1 of the second embodiment. FIG. 14 is a plan view of FIG. Further, FIG. 15 is a cross-sectional view taken along the line AA of FIG.

  As shown in FIG. 14, in this embodiment, the emission region 3 has a single straight boundary line BL orthogonal to the optical axis OA in the plan view (when viewed from the irradiated surface side). It has a circular shape divided into two concentric semicircular regions 3a and 3b having a central angle of 180 ° around the optical axis OA. In the present embodiment, each segmented region is formed in a semicircular shape, but may be formed in a polygonal shape according to the shape of the light flux controlling member 1.

  As shown in FIG. 13, the emission region 3 in this embodiment is the light source 4 side in the optical axis OA direction (the lower side in FIG. 13) when viewed from the boundary line BL direction of both semicircular regions 3 a and 3 b. ) Has a concave V-shape.

  The shape of the emission region 3 in this embodiment is a simple shape as in the first embodiment. Other configurations and operations are the same as those described with reference to FIGS.

  According to the light flux controlling member 1 of this embodiment, the elliptical light distribution characteristic as shown in FIGS. 16 and 17 is reliably obtained as the desired light distribution characteristic (second light distribution characteristic) having regularity. Can get to. Here, the outline of FIG. 16 is the same as FIG. 11 of the first embodiment, and the outline of FIG. 17 is the same as FIG. 12 of the first embodiment.

  The light distribution characteristics in the present embodiment are suitable for applications such as street lamps that irradiate light from an oblique direction to form a perfect circular irradiation spot on the irradiated surface.

  FIG. 18 is a perspective view showing the light flux controlling member 1 of the third embodiment. FIG. 19 is a front view showing the light flux controlling member 1 of the present embodiment. FIG. 20 is a plan view of FIG. 21 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIG. 20, in this embodiment, the emission region 3 has eight concentric sectors with a central angle of 45 ° around the optical axis OA in the plan view (when viewed from the irradiated surface side). It has a circular shape divided into regions 3A to 3H, and each of these fan-shaped regions 3A to 3H intersects with the optical axis OA. In the present embodiment, each segmented area is formed in a fan shape, but may be formed in a polygon according to the shape of the light flux controlling member 1.

  More specifically, as shown in FIG. 18, predetermined four fan-shaped areas 3A, 3C, 3E, and 3G arranged around every one of the eight fan-shaped areas 3A to 3H around the optical axis OA are: As the emission region 3 as one direction around the optical axis OA is viewed in a plan view from the irradiated surface side in the clockwise direction of the optical axis OA (hereinafter the same), the irradiated surface side in the optical axis OA direction (hereinafter the same) It is formed on an upward inclined surface that is inclined upward (in FIG. 18).

  On the other hand, as shown in FIG. 18, four sector regions 3B, 3D, 3F, and 3H other than the above-described predetermined four sector regions 3A, 3C, 3E, and 3G among the eight sector regions 3A to 3H are Further, it is formed on a downwardly inclined surface that inclines toward the light source 4 in the optical axis OA direction as it goes in the clockwise direction of the optical axis OA.

  Then, as shown in FIG. 18, the sector regions 3A, 3C, 3E, and 3G are adjacent to each other in the clockwise direction of the optical axis OA (3B for 3A, 3D for 3C, 3D for 3E, 3F for 3G, 3H) are connected by a ridge line that gradually increases the thickness of the light flux controlling member 1 from the optical axis OA side toward the outer edge of the light flux controlling member 1 (so that the value in the Z direction gradually increases). The sector regions 3B, 3D, 3F and 3H are adjacent to each other in the clockwise direction of the optical axis OA (3C for 3B, 3E for 3D, 3G for 3F, 3A for 3H) and the value in the Z direction. Are connected by a line such that becomes constant, and are connected so as to form a valley fold shape.

  The shape of the emission region 3 in this embodiment is a simple shape that does not hinder the manufacture of the mold and the resin molding using the mold. Other configurations and operations are the same as those described with reference to FIGS.

  According to the light flux controlling member 1 of the present embodiment as described above, the rectangular light distribution characteristic as shown in FIGS. 22 and 23 is reliably obtained as the desired light distribution characteristic (second light distribution characteristic) having regularity. Can get to. Here, the outline of FIG. 22 is the same as FIG. 11 of the first embodiment, and the outline of FIG. 23 is the same as FIG. 12 of the first embodiment.

  The light distribution characteristics in the present embodiment are suitable for use in illuminating a specific rectangular area such as a camera flash.

  The light flux controlling member in this embodiment not only obtains the second light distribution characteristic by the light emitted from the emission region formed on the opposite side of the incident region, but also totally reflects the light incident on the emission region. Thus, the second light distribution characteristic may be obtained by light emitted from the emission region and light emitted from a surface other than the emission region after being totally reflected in the emission region.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. 24 to 33 with a focus on differences from the first embodiment.

  In the present embodiment, for the sake of convenience, components having the same names as those in the first embodiment will be described using the same reference numerals.

  Here, FIG. 24 is a schematic configuration diagram illustrating a light flux controlling member and an optical apparatus including the same according to the present embodiment. FIG. 25 is a plan view of the light flux controlling member of FIG. FIG. 26 is a bottom view of the light flux controlling member of FIG. FIG. 27 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIG. 26, the light flux controlling member 1 in the present embodiment has a rectangular outer periphery on the outside of the projecting portion 7 as shown in FIG. Except that the flat surface 2a perpendicular to the formed optical axis OA is provided, the same as in the first embodiment.

  On the other hand, as shown in FIGS. 24 and 27, the emission region 3 is not on the opposite side in the optical axis OA direction with respect to the incident region 2 as in the first embodiment, but on the side of the incident region 2. The anti-incidence area | region 15 is formed in the position where the output area | region 3 was formed in 1st Embodiment.

  The anti-incident area 15 will be described in more detail. As shown in FIG. 25, the anti-incident area 15 is composed of two congruent rectangles with a single linear boundary line BLs perpendicular to the optical axis OA in the plan view. It has a rectangular shape divided into regions 15a and 15b. Further, as shown in FIGS. 24 and 27, the anti-incident region 15 is the light source 4 side in the optical axis OA direction (lower side in FIG. 24) when viewed from the boundary line BLs direction of both rectangular regions 15a and 15b. It has a V-shape that is line-symmetric with respect to the optical axis OA that is concaved. Further, as shown in FIGS. 24 and 27, the counter-incident region 15 is configured such that the left end of the left rectangular region 15 a is positioned to the right of the left end of the incident region 2 and the right rectangular region 15 b. Is positioned to the left of the right end of the incident region 2. Furthermore, as shown in FIGS. 25 and 26, the front end portion of the anti-incident region 15 is formed at the same position as the front end portion of the incident region 2, and the rear end portion of the anti-incident region 15 Are formed at the same position at the rear end and the rear of the incident region 2.

  In the anti-incident area 15a, light having the first light distribution characteristic (see FIG. 28) shaped in the incident area 2 (mainly the protrusion 7) is transmitted to the member main body 1a as in the first embodiment. After being propagated inside, it enters inside. The anti-incident region 15a is a light beam whose incident angle is larger than the critical angle among the internally incident light, as shown by a symbol L in FIG. Totally reflect toward both sides of the. The anti-incident region 15a has a front end of the incident region 2 in addition to the light directly reaching the incident region 2 as long as the light is shaped so as to have the first light distribution characteristic in the incident region 2. The light that has reached the total reflection at the front side surface 1af of the member main body 1a that connects the front part and the front end part of the anti-incident area 15, and the rear end part of the incident area 2 and the rear end part of the anti-incident area 15 The light which arrived after passing through the total reflection in the rear side surface 1ab of the member main body 1a to be connected may be included.

  Next, the emission area 3 will be described in more detail. As shown in FIGS. 24, 25, and 27, the emission area 3 is divided and arranged at equidistant positions on the left and right sides from the boundary line BLs on the anti-incident area 15. The left emission area 3a and the right emission area 3b are formed. As shown in FIG. 25, both emission regions 3a and 3b have a congruent rectangular shape in a plan view. Further, as shown in FIGS. 24 and 27, both the emission regions 3a and 3b are light that is inclined toward the optical axis OA side from the incident region 2 side toward the counter incident region 15 side in the front view and the cross-sectional view. It has inclined linear shapes that are line-symmetric with respect to the axis OA. More specifically, the left exit area 3a is connected to the left end of the left rectangular area 15a in the anti-incident area 15 and is formed on an inclined plane connected to the left end of the incident area 2. The left emission region 3a also serves as the left side surface of the member main body 1a. The right exit area 3 b is connected to the right end of the right rectangular area 15 b in the anti-incident area 15 and is formed on an inclined plane connected to the right end of the incident area 2. The region 3b also serves as the right side surface of the member main body 1a. Further, the boundary line BLl between the left exit area 3a and the left rectangular area 15a in the anti-incident area 15 and the boundary line BLr between the right exit area 3b and the right rectangular area 15b in the counter incident area 15 are both anti-reflective. It is parallel to the boundary line BLs on the incident region 15. Furthermore, the front end portions of both emission regions 3a and 3b also serve as left and right end portions on the front side surface 1af of the member main body 1a, respectively, and the rear end portions of both emission regions 3a and 3b respectively correspond to the member main body 1a. It also serves as the left and right ends of the rear side surface 1ab.

  Light having the first light distribution characteristic shaped in the incident region 2 is incident on the exit region 3 (3a, 3b) after propagating through the member body 1a. This internally incident light is mainly light totally reflected in the anti-incident region 15 (15a, 15b), but in addition to this, it is shaped so as to have the first light distribution characteristic in the incident region 2. As long as the light is after the light, it may be light that has directly reached from the incident region 2 or light that has reached directly after total reflection at the front side surface 1af or the rear side surface 1ab of the member main body 1a. The emission region 3 shapes the internally incident light into light having a second light distribution characteristic as a desired light distribution characteristic, and emits the light toward the side.

  FIG. 29 shows the second light distribution characteristic shaped by such a light flux controlling member 1 of the present embodiment, and this light distribution characteristic is the two left and right directions in the radial direction with respect to the light source 4. The luminance distribution spreads over a wide range in the (X direction), and the light distribution characteristic is such that the luminance near the light source 4 is suppressed. Such light distribution characteristics are particularly suitable for applications in which a plurality of light flux controlling members 1 are arranged in the boundary line BLs direction to constitute a surface light source.

  The rectangular regions 15a and 15b of the anti-incident region 15 do not have to be flat surfaces, but are curved surfaces having a curvature suitable for securing an incident angle larger than the critical angle with respect to the light from the incident region 2. It may be formed. Further, the left and right emission regions 3a and 3b may be formed on curved surfaces such as convex R surfaces as necessary.

In the present embodiment, the following modifications can be considered.
(Modification)
That is, FIG. 30 is a schematic configuration diagram showing a light flux controlling member in the present embodiment and an optical apparatus including the same as a modification. FIG. 31 is a plan view of the light flux controlling member of FIG. Further, FIG. 32 is a bottom view of the light flux controlling member of FIG. FIG. 33 is a cross-sectional view taken along the line AA in FIG.

  In the light flux controlling member 1 in this modification, a counter-incident region 15 is formed on the opposite side of the incident region 2 in the optical axis OA direction, and an output region 3 is formed on the side of the incident region 2. This is the same as the basic configuration shown in FIGS. As shown in FIG. 33, the anti-incident region 15 in the present modification is formed in a V-shape that is concave on the light source 4 side in the cross-sectional view, similarly to the basic configuration.

  However, in this modification, unlike the basic configuration, the anti-incident region 15 is formed on a rotationally symmetric reverse conical surface (tapered surface) with the optical axis OA as the reference axis, and the emission region 3 is anti-reflective. It is formed on a cylindrical surface (tapered surface) provided around the outer periphery of the incident region 15 and the incident region 2.

  The second light distribution characteristic (not shown) shaped by the light flux controlling member 1 of this modification is the same as that shown in FIG. 29 only on the XZ plane. The light distribution characteristic has a rotationally symmetric shape so that the luminance distribution spreads over a wide range in all directions in the radial direction with respect to the light source 4.

  In addition, this invention is not limited to embodiment mentioned above, A various change can be made in the limit which does not impair the characteristic of this invention.

DESCRIPTION OF SYMBOLS 1 Light flux control member 2 Incident area 3 Outgoing area 4 Light source 7 Protrusion part

Claims (8)

An incident region where light emitted from the light source is incident;
An exit region that is located on the opposite side in the optical axis direction with respect to the incident region, and that emits the light incident on the incident region toward the irradiated surface side, and
A light flux controlling member that shapes light emitted from the light source into light having desired light distribution characteristics and irradiates the irradiated surface,
The incident area has a concentric annular shape centered on the optical axis when viewed from the light source side, and has a diameter such that a cross section cut at an arbitrary virtual plane including the entire optical axis has a saw-tooth shape. A plurality of protrusions adjacent to each other in the direction;
The protrusion is formed with an incident portion where light emitted from the light source is incident and refracts the incident light, and an outer position in the radial direction with respect to the incident portion with respect to the optical axis. A total reflection part that totally reflects the light incident on the incident part toward the emission region;
The incident region has light having a first light distribution characteristic such that the light emitted from the light source exhibits a maximum value of light intensity in two predetermined directions symmetric with respect to the optical axis on the virtual plane. To shape,
The exit area is configured to shape the light having the first light distribution characteristic shaped by the incident area into light having the second light distribution characteristic which is a desired light distribution characteristic. Element. The emission region is formed in a conical shape convex toward the irradiated surface with the optical axis as a symmetry axis, and the circular second light distribution characteristic that is rotationally symmetric with respect to the optical axis is obtained. The light flux controlling member according to claim 1. The emission region is divided into two regions having a central angle of 180 ° around the optical axis when viewed in plan from the irradiated surface side, and when viewed from the extending direction of the boundary line of the two regions The second light distribution that is formed so as to exhibit a concave V-shape on the light source side in the optical axis direction, and that the irradiation range of the emitted light from the light flux controlling member on the irradiated surface is elliptic. The light flux controlling member according to claim 1, wherein characteristics are obtained. The exit area is
When viewed in plan from the irradiated surface side, it is divided into eight regions with a central angle of 45 ° around the optical axis,
Four of the eight boundary lines formed between adjacent regions of the eight regions gradually increase the thickness of the light flux control member from the optical axis side toward the outer edge side of the light flux control member. And every other ridgeline is formed around the optical axis, and the remaining four of the eight boundary lines are formed in valleys between the adjacent regions,
2. The light flux controlling member according to claim 1, wherein the second light distribution characteristic is obtained such that an irradiation range of the emitted light from the light flux controlling member on the irradiated surface is rectangular. An incident region where light emitted from the light source is incident;
The light incident on the incident region is located on the opposite side in the optical axis direction, and the light incident on the incident region is internally incident. An anti-incident region that totally reflects outward,
An exit region that is located radially outside the anti-incident region and emits light totally reflected by the anti-incident region toward the radially outer side;
A light flux controlling member that shapes light emitted from the light source into light having desired light distribution characteristics,
The incident region has a concentric annular shape centered on the optical axis when viewed from the light source side, and a cross section cut at an arbitrary virtual plane including the entire optical axis has a saw-tooth shape. A plurality of protrusions adjacent to each other in the radial direction;
The protrusion is formed with an incident portion where light emitted from the light source is incident and refracts the incident light, and an outer position in the radial direction with respect to the incident portion with respect to the optical axis. A total reflection part that totally reflects the light incident on the incident part toward the anti-incident area;
The incident region has light having a first light distribution characteristic such that the light emitted from the light source exhibits a maximum value of light intensity in two predetermined directions symmetric with respect to the optical axis on the virtual plane. To shape,
The exit area is configured to shape the light having the first light distribution characteristic shaped by the incident area into light having the second light distribution characteristic which is a desired light distribution characteristic. Element. A light source that emits light;
An optical apparatus comprising: the light flux controlling member according to claim 1. When the light emitted from the light source is incident on the incident area of the light flux controlling member and emitted from the light emitting area of the light flux controlling member toward the irradiated surface, the light is converted into light having desired light distribution characteristics. A light beam shaping method for shaping,
As the light flux controlling member, the incident region has a concentric ring shape with the optical axis as a center when viewed in plan from the light source side, and a section cut along an arbitrary virtual plane including the entire optical axis is a saw blade A plurality of protrusions adjacent to each other in the radial direction so as to have a shape, and the protrusions receive light emitted from the light source and refract the incident light; and On the other hand, it is formed at the outer position in the radial direction with respect to the optical axis, and has a total reflection part that totally reflects the light incident on the incident part toward the emission region,
Light having a first light distribution characteristic such that light emitted from the light source in the incident region shows a maximum value of light intensity in two predetermined symmetric directions with respect to the optical axis on the virtual plane. To shape,
Next, the light beam shaping method characterized by shaping the light having the first light distribution characteristic into light having the second light distribution characteristic as a desired light distribution characteristic in the emission region. The light emitted from the light source is incident on the incident region of the light flux controlling member, and is totally reflected outward in the radial direction in the anti-incident region of the light flux controlling member, and then radially emitted from the emitting region of the light flux controlling member. A light beam shaping method for shaping the light into light having a desired light distribution characteristic when emitted toward the outside,
As the light flux controlling member, the incident region has a concentric ring shape with the optical axis as a center when viewed in plan from the light source side, and a section cut along an arbitrary virtual plane including the entire optical axis is a saw blade A plurality of protrusions adjacent to each other in the radial direction so as to form a shape, and the protrusions receive light emitted from the light source and refract the incident light; and the incident part Using a total reflection part that is formed at an outer position in the radial direction with respect to the optical axis and that totally reflects the light incident on the incident part toward the anti-incident area,
Light having a first light distribution characteristic such that light emitted from the light source in the incident region shows a maximum value of light intensity in two predetermined symmetric directions with respect to the optical axis on the virtual plane. To shape,
A light beam shaping method characterized by shaping light having the first light distribution characteristic into light having a second light distribution characteristic as a desired light distribution characteristic in the emission region.