JP5766044B2 - Luminous flux control member, light emitting device including the luminous flux control member, and surface light source device including the light emitting device - Google Patents

Description

  The present invention relates to a light flux controlling member, a light emitting device including the light flux controlling member, and a surface light source device including the light emitting device, and particularly suitable for controlling a traveling direction of light emitted from a light emitting element. The present invention relates to a control member, a light emitting device including the light flux controlling member, and a surface light source device including the light emitting device.

  Conventionally, for applications such as backlights for liquid crystal display devices, a plurality of point light sources are arranged on the back side (directly below) of the light diffusion plate, and the light from each light source is diffused by the light diffusion plate and directly below The type surface light source device has often been adopted because of its advantages such as high brightness and suitability for large area image display.

  Conventionally, in this type of surface light source device, various developments have been made with the aim of suitably realizing large-area illumination with a small number of point light sources from the viewpoint of cost reduction and the like. As an example, there is also a surface light source device in which a plurality of side view LEDs, which are point light sources, are arranged in the center of the surface light source device, and the emitted light from the side view LEDs is guided to the hollow light guide region to have a uniform luminance distribution. It has been proposed (Patent Document 1 (FIGS. 5 and 6)).

  In addition, there is a technology for obtaining light in the emission direction similar to that of the side view LED of Patent Document 1 by converting the light emission direction of the top view LED by the light flux control member by a light emitting device that combines the top view LED and the light flux control member. (Patent Document 2 (FIG. 4, FIG. 5)). When the light emitted from such a light emitting device is observed in a plan view, it is not an isotropic light distribution from the central axis to the 360 degree direction, and two directions of 0 degrees and 180 degrees are the main emission directions. Is observed as a light distribution characteristic.

JP 2010-009785 A US Pat. No. 7,390,109

  However, the light-emitting device of Patent Document 2 has a light distribution characteristic (in the form of a sector in which the central angle portion is placed on the light-emitting device) having a slight spread in a direction orthogonal to the main emission direction in a plan view. Therefore, instead of the side view LED of Patent Document 1, the light emitting device of Patent Document 2 is used for the surface light source device of Patent Document 1 so that the main emission direction is orthogonal to the LED array. The emitted light from the adjacent light emitting devices overlaps to illuminate the illuminated surface, causing a bright part.

  Further, in the light flux controlling member used in the light emitting device of Patent Document 2, the amount of light that illuminates the irradiated surface at a position away from the light emitting device in the main emission direction is insufficient due to the large spread of light in the main emission direction. The problem of being easy arises.

  Therefore, the present invention has been made in view of such problems, and suppresses the useless spread of light emitted from the light emitting device, and improves the luminance distribution of the light flux controlling member alone to a shape close to a rectangular shape. Thus, when the surface light source is configured by arranging a plurality of light flux control members, it is possible to sufficiently alleviate the light interference between the adjacent light flux control members, and thus the in-plane luminance distribution. An object of the present invention is to provide a light beam control member capable of improving uniformity, a light emitting device including the light beam control member, and a surface light source device including the light emitting device.

  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 a light flux controlling member that controls the traveling direction of light emitted from the light emitting element, and is a predetermined perpendicular to the optical axis direction. The first direction is the first direction, the direction perpendicular to both the first direction and the optical axis is the second direction, and the plane perpendicular to the first direction and including the optical axis is the first virtual When the plane is a plane, and the plane perpendicular to the second direction and including the optical axis is the second imaginary plane, the plane is long in the first direction, and is disposed to face the light emitting element. A light emitting element facing surface portion located on the back surface side of the light flux controlling member, an anti-light emitting element facing surface portion elongated in the first direction on the surface side opposite to the light emitting element facing surface portion, and the repulsion The light emitting element facing surface from both end portions in the first direction of the optical element facing surface portion A pair of first side surface portions respectively extending toward both end portions in the first direction, and the light emitting element facing surface portion from the both end portions in the second direction of the anti-light emitting element facing surface portion. A pair of second side surfaces respectively extending toward both ends in the second direction and connected to both ends of the pair of first side surfaces in the second direction. The light emitting element facing surface portion is formed over a predetermined range from the optical axis in a direction perpendicular to the optical axis, and has an incident surface on which light emitted from the light emitting element is incident. A recess having a valley bottom formed at a position intersecting with the first virtual plane, and the recess totally reflects the light of the light emitting element that has reached from the incident surface toward the pair of first side surfaces; Has first total reflection surface The first total reflection surface is formed in a shape in which the distance from the first virtual plane gradually increases from the valley bottom toward the direction away from the light emitting element, and the pair of second side surface portions Each having a second total reflection surface that totally reflects the light of the light emitting element that has reached from the incident surface toward the pair of first side surface portions and the first total reflection surface, The first side surface portion is formed in a shape in which the distance from the first virtual plane gradually decreases from the back surface side toward the front surface side, and the light of the light emitting element that has arrived after propagating through the light flux controlling member , Respectively, in a direction away from the first imaginary plane in the first direction, and the pair of second total reflection surfaces are formed from the first side surface side. I went to the first virtual plane Thus, the second virtual plane is curved so that the distance from the second virtual plane gradually decreases.

  According to the first aspect of the invention, unlike the conventional plane (a plane parallel to the second virtual plane), the pair of second total reflection surfaces are curved so as to close each other. Compared to the case where the second total reflection surface is a plane, the total reflection direction of the light from the light emitting element on the second total reflection surface having the concave curve surface is compared. Thus, the projection component onto the plane orthogonal to the optical axis at an angle with the first direction can be controlled to be small. As a result, it is possible to prevent the light of the light emitting element from being largely changed in the optical path direction in the second direction on the second total reflection surface. The luminance distribution can be prevented from spreading in the second direction so as to collapse from the rectangular shape, and the light emission direction from the emission surface can be converged to the first direction side accordingly. Therefore, it is possible to realize a luminance distribution having a high degree of approximation to a rectangular shape that is long in the first direction. If a plurality of such light flux control members are arranged along with the light emitting elements corresponding thereto to form a surface light source, for example, along the second direction, light between the light flux control members adjacent to each other. Therefore, the uniformity of the in-plane luminance distribution can be reliably improved.

  The light flux controlling member according to claim 2 is characterized in that, in claim 1, the light exit surface is formed so as to exhibit a convex shape in the second imaginary plane or a cross section parallel thereto. It is in.

  According to the second aspect of the present invention, since the light can be distributed over a wide range in the first direction by the convex emission surface, the number of light emitting elements is reduced and the in-plane luminance distribution is made uniform. Can be made effective.

  Further, the light beam control member according to claim 3 is characterized in that, in claim 1 or 2, the light emitting element facing surface portion is located outside the direction perpendicular to the optical axis with respect to the incident surface with the optical axis as a center. A plurality of grooves are formed so as to be aligned in the first direction, and have a groove portion having a wedge shape in the second virtual plane or a cross section parallel to the second virtual plane.

  According to the third aspect of the present invention, even when the light of the light emitting element reflected by the Fresnel on the emission surface reaches the light emitting element facing surface portion, the light is separated from the first total reflection surface by the plurality of grooves. Since the total reflection can be performed in the direction of deviating, the luminance near the light source can be effectively reduced.

  Still further, the light flux controlling member according to claim 4 is characterized in that in any one of claims 1 to 3, the second total reflection surface is formed as a concave R surface having a predetermined radius of curvature. There is in point.

  According to the fourth aspect of the invention, the design, manufacture, and evaluation of dimensional accuracy of the second total reflection surface can be facilitated.

  In addition, the light flux controlling member according to claim 5 is characterized in that in any one of claims 1 to 4, the exit surface is formed on a convex R surface having a predetermined radius of curvature. .

  According to the fifth aspect of the present invention, the design, manufacture, and evaluation of dimensional accuracy of the emission surface can be facilitated.

  Further, the light flux controlling member according to claim 6 is characterized in that in any one of claims 1 to 5, the first total reflection surface and the emission surface are symmetrical with respect to the first virtual plane. The second total reflection surface is formed in a plane symmetry shape with the second virtual plane as a symmetry plane.

  According to the sixth aspect of the present invention, the symmetry of the luminance distribution with reference to the first virtual plane and the second virtual plane can be ensured, so the degree of approximation of the luminance distribution to the rectangular shape In addition, the design, manufacture, and evaluation of dimensional accuracy of the first total reflection surface, the second total reflection surface, and the emission surface can be facilitated.

  Still further, the light flux controlling member according to claim 7 is characterized in that, in any one of claims 1 to 6, the first total reflection surface is on the second virtual plane or on the first. An angle formed by a tangent at an arbitrary point on a cross section parallel to the two virtual planes and the first virtual plane is formed in a shape that gradually increases so as to approach a right angle as the distance from the first virtual plane increases. There is in point.

  According to the seventh aspect of the invention, the surface shape of the first total reflection surface can be changed to a surface shape suitable for total reflection according to the light of the light emitting element at each emission angle. The luminance directly above the light source can be more effectively suppressed.

  The light emitting device according to claim 8 is characterized in that the light flux controlling member and the light emitting element according to any one of claims 1 to 7 are provided.

  According to the eighth aspect of the present invention, a luminance distribution with a high degree of approximation to a rectangular shape elongated in the first direction can be realized. If a plurality of arrays are arranged along the second direction, the interference of light between adjacent light flux controlling members can be sufficiently mitigated, so that the uniformity of the in-plane luminance distribution is reliably improved. Can do.

Furthermore, the features of the surface light source device according to claim 9, the light emitting device according to claim 8, a plurality of aligned with a predetermined interval in the second direction according to claim 1, wherein the plurality of light emitting Reflective means for reflecting light emitted from the emission surfaces of the plurality of light flux controlling members is provided at a position on the first direction side according to claim 1 with respect to the apparatus, and orthogonal to the optical axis of each of the light flux controlling members. Thus, an optical sheet is provided that is disposed so as to face each of the light flux controlling members and the reflecting means and emits incident light from the reflecting means .

According to the ninth aspect of the present invention, a plurality of light emitting devices capable of realizing a luminance distribution having a high degree of approximation to a rectangular shape elongated in the first direction are arranged along the second direction. And a reflecting means for reflecting the light emitted from the light emission surfaces of the plurality of light flux controlling members at a position on the first direction side of the plurality of light emitting devices. By providing an optical sheet that is disposed opposite to each light beam control member and the reflection means so as to be orthogonal to the optical axis of the light beam control member and that emits incident light from the reflection means, the front side from the optical sheet. The light emitted from the light flux control member adjacent to each other can be made light having in- plane luminance distribution with improved uniformity in which light interference between adjacent light flux control members is sufficiently relaxed.

  Furthermore, the surface light source device according to claim 10 is characterized in that, in claim 9, the row of light emitting devices along the second direction is aligned in the first direction with the first direction. A plurality of columns are arranged in parallel with a predetermined interval larger than the interval.

  And according to this invention concerning Claim 10, the uniformity of in-plane luminance distribution can be improved still more efficiently.

  According to the present invention, the luminous flux control members adjacent to each other when the surface light source is configured by arranging a plurality of luminous flux control members by improving the luminance distribution of the luminous flux control member alone to be closer to a rectangular shape. Can be sufficiently mitigated, and as a result, the uniformity of the in-plane luminance distribution can be improved.

The perspective view which shows embodiment of the light beam control member which concerns on this invention Front view of the light flux controlling member of FIG. Plan view of FIG. Left side view of FIG. Bottom view of FIG. AA sectional view of FIG. Explanatory drawing for demonstrating the optical function of a 2nd total reflection surface in embodiment of the light beam control member which concerns on this invention Explanatory drawing for demonstrating the optical function of an output surface in embodiment of the light beam control member which concerns on this invention Explanatory drawing for demonstrating the optical function of a groove part in embodiment of the light beam control member which concerns on this invention The top view which shows the 1st form of the surface light source device which concerns on this invention AA sectional view of FIG. The top view which shows the 2nd form of the surface light source device which concerns on this invention The top view which shows the 3rd form of the surface light source device which concerns on this invention AA sectional view of FIG. Sectional drawing which shows the 4th form of the surface light source device which concerns on this invention The top view which shows the 5th form of the surface light source device which concerns on this invention AA sectional view of FIG. Front view showing a conventional light flux controlling member used as a comparative example Plan view of FIG. Left side view of FIG. 18 is a bottom view of FIG. Luminance distribution diagram showing the result of simulation using the light flux controlling member of the present invention for verifying the influence of the second total reflection surface on the luminance distribution Luminance distribution diagram showing results of simulation using a conventional light flux controlling member for verifying the influence of the second total reflection surface on the luminance distribution Luminance distribution diagram showing the result of simulation using the light flux controlling member of the present invention for verifying the influence of the exit surface on the luminance distribution Luminance distribution diagram showing the result of simulation using the light flux controlling member of the present invention for verifying the influence of the groove on the luminance distribution Luminance distribution diagram showing the result of simulation using the light flux controlling member of the present invention different from FIG. 25 for verifying the influence of the groove on the luminance distribution Luminance distribution diagram showing the result of simulation using the light flux controlling member of the present invention different from that shown in FIGS. 25 and 26 for verifying the influence of the groove on the luminance distribution. Luminance distribution diagram showing results of simulation using the light flux controlling member of the present invention for verifying the influence of the reflection sheet on the luminance distribution The figure which shows the simulation result of in-plane luminance distribution using the light beam control member of the best mode of this invention The figure which shows the simulation result of in-plane luminance distribution when not having a light beam control member The figure which shows the simulation result of in-plane luminance distribution using the conventional light beam control member shown in FIGS.

  Hereinafter, embodiments of a light flux controlling member, a light emitting device, and a surface light source device according to the present invention will be described with reference to FIGS.

(Form of light flux controlling member and light emitting device)
FIG. 1 is a perspective view showing a light flux controlling member 1 in the present embodiment. FIG. 2 is a front view of the light flux controlling member 1, and the rear view is the same as FIG. 3 is a plan view of FIG. FIG. 4 is a left side view of FIG. 2, and a right side view is the same as FIG. FIG. 5 is a bottom view of FIG. 6 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIGS. 2, 5, and 6, the light flux controlling member 1 in the present embodiment is elongated in a predetermined first direction (Y-axis direction in FIGS. 5 and 6) orthogonal to the optical axis OA direction. The light emitting element facing surface 2 is formed so as to face the light emitting element 3 and is located on the back side of the light flux controlling member 1. In addition, as the light emitting element 3, what emits light in the direction (Z-axis direction in FIG. 6) perpendicular | vertical with respect to element arrangement surfaces, such as top view LED mentioned above, can be used suitably. Such a light emitting element 3 constitutes the light emitting device 4 in this embodiment together with the light flux controlling member 1.

  2, 3, and 6, the light flux controlling member 1 is anti-light-emitting formed on the surface side of the light flux controlling member 1 that is opposite to the light emitting element 3 with respect to the light emitting element facing surface portion 2. An element facing surface portion 5 is provided. Similar to the light emitting element facing surface portion 2, the counter light emitting element facing surface portion 5 is formed long in the Y-axis direction. However, the anti-light emitting element facing surface portion 5 is formed shorter in the Y-axis direction than the light emitting element facing surface portion 2, and both end portions in the longitudinal direction of the anti-light emitting element facing surface portion 5 are in the longitudinal direction of the light emitting element facing surface portion 2. Is located on the inner side (closer to the optical axis OA) than both end portions.

  Further, as shown in FIGS. 2 and 6, the light flux controlling member 1 extends from both end portions in the longitudinal direction (first direction) of the anti-light emitting element facing surface portion 5 to both end portions in the longitudinal direction of the light emitting element facing surface portion 2. And a pair of left and right first side surface portions 7L and 7R respectively extending.

  Furthermore, as shown in FIG. 3, the light flux controlling member 1 emits light from both ends in the second direction (X-axis direction in FIG. 3) orthogonal to the longitudinal direction of the anti-light emitting element facing surface portion 5 and the optical axis OA direction. It has a pair of front and rear second side surface portions 8F and 8R respectively extending toward both end portions in the X-axis direction of the element facing surface portion 2. These second side surface portions 8F and 8R are connected to both end portions in the X-axis direction of the first side surface portions 7L and 7R, respectively. More specifically, the second side view 8F on the front side is connected to the front end portion of the anti-light emitting element facing surface portion 5 and the front end portions of the first side surface portions 7L and 7R, while the second side surface on the rear side. 8R is connected to the rear end portion of the counter-light emitting element facing surface portion 5 and the rear end portions of the first side surface portions 7L and 7R.

  More specific configurations and optical functions (actions) of the surface portions 2, 5, 7, and 8 of the light flux controlling member 1 are as follows.

  That is, first, as shown in FIGS. 5 and 6, the light emitting element facing surface portion 2 has a planar shape on which light emitted from the light emitting element 3 is incident over a predetermined range in a direction perpendicular to the optical axis OA. The incident plane 10 is formed. As shown in FIG. 6, the light (dashed line portion) of the light emitting element 3 that has entered the incident plane 10 is refracted according to Snell's law, and the anti-light emitting element facing surface 5 side on the optical path inside the light flux controlling member 1 Proceed toward. However, in FIG. 6, only one light beam is representative of light beams emitted from the light emitting element 3 at a predetermined spread angle (a spread angle according to a Lambertian distribution in the case of a general LED). Is shown in FIG. In addition, the light of the light emitting element 3 that has entered the incident plane 10 through the optical axis OA and proceeds perpendicularly without being refracted.

  As shown in FIGS. 2 and 6, the counter-light-emitting element facing surface portion 5 is recessed in a substantially V shape toward the light-emitting element 3, and a valley bottom is formed at a position intersecting the first virtual plane S <b> 1. The inner surface of the recess 11 is a first total reflection surface 12. As shown in FIGS. 2 and 6, the first total reflection surface 12 is orthogonal to the Y-axis direction including the optical axis OA as it goes away from the light emitting element 3 with the valley bottom as a base point (upward in FIG. 2). The distance from the first virtual plane S1 (distance in the Y-axis direction) is gradually increased. As shown in FIG. 6, the light from the light emitting element 3 incident from the incident plane 10 reaches the first total reflection surface 12 after reaching the first total reflection surface 12 after traveling on the optical path inside the light flux controlling member 1 (internal incidence). ) Then, the first total reflection surface 12 transmits the light incident internally at an incident angle larger than the critical angle out of the light of the light emitting element 3 arriving from the incident plane 10 to the left and right first side surface portions 7L and 7R. Totally reflect toward. More specifically, using FIG. 6, the light incident on the first total reflection surface 12 on the left side of the first virtual plane S1 is totally directed toward the first side surface portion 7L on the left side. On the other hand, the light reflected and incident on the first total reflection surface 12 on the right side of the first virtual plane S1 is totally reflected toward the first side surface portion 7R on the right side.

  Further, the front and rear second side surface portions 8F and 8R are respectively formed as second total reflection surfaces 8F and 8R. The second total reflection surfaces 8 </ b> F and 8 </ b> R are refracted largely in the front-rear direction (X-axis direction) than the light reaching the first total reflection surface 12 out of the light of the light emitting element 3 incident on the incident plane 10. The incident light reaches (internally incident) after traveling on the optical path inside the light flux controlling member 1. Then, the second total reflection surfaces 8F and 8R transmit the light incident inside at an incident angle larger than the critical angle out of the light of the light emitting element 3 reaching from the incident plane 10 to the left and right first side surface portions 7L, The light is totally reflected toward 7R and the first total reflection surface 12. More specifically with reference to FIG. 3, the light incident on the left side of the first virtual plane S1 on the second total reflection surfaces 8F and 8R is directed toward the first side surface portion 7L on the left side. On the other hand, the light that is internally incident on the portion on the right side of the first virtual plane S1 on the second total reflection surfaces 8F and 8R is totally reflected toward the first side surface portion 7R on the right side. . In FIG. 3, light that is internally incident on a portion of the front-side second total reflection surface 8 </ b> F that is on the right side of the first virtual plane S <b> 1 is typically illustrated as one light beam (broken line portion). .

  Furthermore, the left and right first side surface portions 7L and 7R are formed as emission surfaces 7L and 7R, respectively. As shown in FIGS. 2 and 3, the emission surfaces 7 </ b> L and 7 </ b> R are arranged in the first direction from the back surface side of the light flux controlling member 1 to the front surface side (in other words, the side opposite to the light emitting element 3 (upward)). The distance from the virtual plane S1 in the Y-axis direction is formed to be gradually reduced. As shown in FIGS. 3 and 6, the light exiting surfaces 7 </ b> L and 7 </ b> R are totally reflected by the light of the light emitting element 3 totally reflected by the first total reflection surface 12 and the second total reflection surfaces 8 </ b> F and 8 </ b> R. The reflected light of the light emitting element 3 arrives after traveling (propagating) on the optical path inside the light flux controlling member 1. Then, the emission surfaces 7L and 7R emit the light of the light emitting element 3 that has arrived in this way mainly in a direction away from the first virtual plane S1 in the Y-axis direction.

  In this way, the light emitted directly upward from the light emitting element 3 is converted into light directed to the side by controlling the traveling direction by the light flux controlling member 1.

  In the present embodiment, as shown in FIG. 3, the second total reflection surfaces 8F and 8R are not on the plane as in the invention described in Patent Document 1, but toward the first virtual plane S1 side. Therefore, it is formed in a curved surface shape that is curved so that the distance in the X-axis direction between the second virtual plane S2 orthogonal to the X-axis direction including the optical axis OA gradually decreases. More specifically, both of the second total reflection surfaces 8F and 8R are formed in a concave curved surface shape that is curved so as to make the interval in the X-axis direction closest to each other on the first virtual plane S1. .

  And according to such a structure, as shown in FIG. 7, the total reflection direction of the light of the light emitting element 3 in the 2nd total reflection surface 8 (For convenience, F and R are abbreviate | omitted.) Compared to the case of the straight second total reflection surface 8 ′, the projection components (α (present invention), α ′ (conventional) in FIG. 7) on the XY plane at an angle formed with the Y-axis direction are small. Can be controlled in a direction. Therefore, according to the present embodiment, it is possible to prevent the light of the light emitting element 3 from being largely changed in the X-axis direction on the second total reflection surface 8. It is possible to suppress the luminance distribution from spreading in the X-axis direction so as to be broken from the rectangular shape due to the light traveling. As a result, the emission direction of the light from the emission surface 7 can be converged to the Y-axis direction side, so that a luminance distribution with a high degree of approximation to a rectangular shape elongated in the Y-axis direction is realized. be able to.

  If a plurality of such light flux controlling members 1 and light emitting elements 3 corresponding thereto (that is, light emitting devices 4) are arranged along the X-axis direction so as to form a surface light source, for example, light flux control adjacent to each other. Between the members 1, it is possible to sufficiently spread light over the entire surface while sufficiently reducing the overlap (light interference) of the high luminance regions in the luminance distribution and suppressing the occurrence of bright portions. The uniformity of the in-plane luminance distribution can be improved with certainty.

  In addition to the above configuration, in the present embodiment, as shown in FIGS. 2 and 6, the emission surfaces 7L and 7R have a convex shape having a curvature in the second virtual plane S2 or a cross section parallel to the second virtual plane S2. It is formed in a curved surface curved so as to exhibit.

  According to such a configuration, as shown in FIG. 8, the light emission direction of the light emitting element 3 on the emission surface 7 (for convenience, L and R are omitted in the figure) is set to the conventional straight emission surface 7. Compared with the case of ', the projection component (β (present invention), β ′ (conventional) in FIG. 8) of the angle formed with the Y-axis direction on the YZ plane can be controlled to be smaller. Therefore, according to the convex curved exit surfaces 7L and 7R, the light of the light emitting element 3 can be distributed over a wide range in the Y-axis direction, so that the number of lamps of the light emitting element 3 can be reduced and the in-plane luminance distribution can be reduced. It is possible to effectively achieve both uniformity.

  In addition to the above-described configuration, as shown in FIGS. 5 and 6, in the present embodiment, the light emitting element facing surface portion 2 has an optical axis OA with respect to the incident plane 10 with the optical axis OA as a reference (center). A plurality (eight in the present embodiment) of groove portions 14 that are long in the X-axis direction and continuously arranged in the Y-axis direction are provided at outer positions in the orthogonal direction. A part of the groove portion 14 can also function as an incident surface of light emitted from the light emitting element 3 at a large angle from the optical axis OA. As shown in FIG. 6, each groove portion 14 has a wedge shape in the second virtual plane S2 or a cross section parallel to the second virtual plane S2. Moreover, each groove part 14 is comprised by the 1st inclined surface 14a and the 2nd inclined surface 14b connected with the edge part on the opposite side to 1st virtual plane S1 in the Y-axis direction. The first inclined surface 14a is formed on an inclined surface that is inclined to the opposite side to the light emitting element 3 toward the opposite side to the first virtual plane S1 in the Y-axis direction. On the other hand, the second inclined surface 14b is formed on an inclined surface that is inclined toward the light emitting element 3 side toward the opposite side of the first virtual plane S1 in the Y-axis direction. As shown in FIG. 6, the first inclined surface 14a is a gentler inclined surface than the second inclined surface 14b. That is, if the angle (acute angle) formed between the first inclined surface 14a and the XY plane is θ1, and the angle (acute angle) formed between the second inclined surface 14b and the XY plane is θ2, θ2> θ1 is established. In this embodiment, θ1 = 20 ° and θ2 = 80 °.

  In the case where the outside of the incident plane 10 is not a groove but a plane, light that is Fresnel-reflected by the plane portion or the plane portion is transmitted and the substrate upper surface (the substrate on which the light emitting element 3 is mounted or a reflection disposed thereon) The light reflected on the surface) is likely to reach the first total reflection surface 12, and when the light is emitted from the first total reflection surface 12, a bright portion is generated on the irradiated surface immediately above the light source. It becomes easy to let.

  According to the configuration of the present embodiment, as shown in FIG. 9, Fresnel reflection of light occurs on the emission surface 7 (for convenience, L and R are omitted in the figure), and this light is emitted from the light emitting element facing surface portion 2. Even when the light reaches the outside of the incident plane 10, the optical path of this light can be changed in the direction away from the first total reflection surface 12 by the plurality of grooves 14 (mainly the first inclined surface 14 a). it can. Thereby, since the reflected light from the light emitting element facing surface portion 2 is incident on the first total reflection surface 12 at an incident angle equal to or less than the critical angle, light leakage directly above the light source can be suppressed. Can be effectively reduced.

  In addition to the above configuration, in the present embodiment, as shown in FIG. 3, the second total reflection surfaces 8F and 8R are formed as concave R surfaces having a predetermined radius of curvature. However, the concave R surface has a curvature in plan view (having a curvature in the Y-axis direction in FIG. 3), and its center of curvature exists on the first virtual plane S1, but is parallel to the optical axis OA. In any direction (there is no curvature in the Z-axis direction in FIG. 4).

  According to such a configuration, the design, manufacture, and evaluation of dimensional accuracy of the second total reflection surfaces 8F and 8R can be facilitated.

  In addition to the above configuration, in the present embodiment, as shown in FIGS. 2 and 6, the emission surfaces 7 </ b> L and 7 </ b> R are formed as convex R surfaces having a predetermined radius of curvature. However, the convex R surface has a curvature in a direction parallel to the optical axis OA (having a curvature in the Z-axis direction in FIG. 2), and has no curvature in a plan view (X in FIG. 4). There is no curvature in the axial direction).

  According to such a configuration, the design, manufacture, and evaluation of dimensional accuracy of the emission surfaces 7L and 7R can be facilitated.

  In addition to the above-described configuration, in the present embodiment, as shown in FIGS. 2 and 6, the first total reflection surface 12 and the emission surfaces 7L and 7R have the first virtual plane S1 as a symmetry plane. It is formed in a plane symmetrical shape. As shown in FIG. 3, the second total reflection surfaces 8F and 8R are formed in a plane-symmetric shape with the second virtual plane S2 as a symmetry plane.

  According to such a configuration, the symmetry of the luminance distribution with reference to the first virtual plane S1 and the second virtual plane S2 can be ensured, so the degree of approximation of the luminance distribution to the rectangular shape can be increased. Furthermore, the design, manufacture, and evaluation of dimensional accuracy of the first total reflection surface 12, the second total reflection surfaces 8F and 8R, and the emission surfaces 7L and 7R can be facilitated.

  In addition to the above-described configuration, as shown in FIGS. 2 and 6, in the present embodiment, the first total reflection surface 12 is on the second virtual plane S2 or parallel to the second virtual plane S2. The angle formed between the tangent line at an arbitrary point on the cross section and the first virtual plane S1 is formed so as to gradually increase so as to approach a right angle as the distance from the first virtual plane S1 increases.

  According to such a configuration, the surface shape of the first total reflection surface 12 is a surface shape suitable for total reflection of each of these lights according to the emitted light at each emission angle from the light emitting element 3. Therefore, the luminance directly above the light source can be more effectively suppressed.

  In addition, you may form the light beam control member 1 by resin materials, such as PMMA (polymethyl methacrylate), PC (polycarbonate), and EP (epoxy resin), for example.

  In addition, the circular convex portion 15 formed outside the groove portion 14 in the light emitting element facing surface portion 2 secures a gap between the light flux controlling member 1 and the light emitting element 3 when the light flux controlling member 1 is disposed to face the light emitting element 3. You may use for.

  The light flux controlling member 1 having the above configuration can constitute various types of surface light source devices as described below according to the arrangement mode.

(Form of surface light source device)
(First form)
FIG. 10 is a plan view showing the surface light source device 16 of the first embodiment, and FIG. 11 is a cross-sectional view taken along line AA of FIG.

  The surface light source device 16 is formed by arranging a plurality of light flux control members 1 according to the present embodiment in a rectangular space 17 in a plan view with a predetermined interval in the X-axis direction. Of course, each light flux controlling member 1 is disposed opposite to the corresponding light emitting element 3.

  Here, the housing 17 will be described in detail. As shown in FIGS. 10 and 11, the inner surface of the housing 17 is perpendicular to the bottom surface 18 parallel to the XY plane and both ends of the bottom surface 18 in the X-axis direction. The left and right side surfaces 19 and 20 are connected to each other, and the upper and lower side surfaces 21 and 22 are connected to both ends of the bottom surface 18 in the Y-axis direction. As shown in FIG. 11, the side surfaces 21 and 22 are formed on an upward inclined surface that approaches the light emitting surface of the surface light source device 16 as the distance from the light emitting element 3 increases. Furthermore, as shown in FIG. 11, the side surface 21 and the side surface 22 are formed in a plane-symmetric shape with the first virtual plane S1 as a plane of symmetry. That is, the inclination angles of the side surfaces 21 and 22 with respect to the bottom surface 18 coincide with each other. On the inner surface of the casing 17, a reflection surface 24 is formed by sticking a reflection sheet made of PET or the like (for example, UXSP188 manufactured by Teijin DuPont). Hereinafter, a portion of the reflecting surface 24 formed on the inclined surfaces 21 and 22 is referred to as an inclined reflecting surface 24a.

  As shown in FIG. 11, a plurality of light emitting elements 3 are aligned on the bottom surface 18 with a predetermined interval in the X-axis direction, and each light emitting element 3 applies an electric signal to them. And mounted on the bottom surface 18 in a state of being mounted on a substrate 25 provided with a lead, a control circuit, and the like. Each light emitting element 3 has a predetermined light distribution with a certain degree of directivity (in the case of a general LED) toward the front (left side in FIG. 11) where the corresponding light flux controlling members 1 are arranged to face each other. Emits light according to the Lambertian distribution. The light flux controlling member 1 is aligned so that its optical axis OA is coaxial with the central axis (center light) of the emitted light of the corresponding light emitting element 3.

  Further, as shown in FIG. 11, an optical sheet 27 that shields the front opening of the housing 17 is disposed in front of the housing 17, and this optical sheet 27 is an optical axis of each light flux controlling member 1. The light flux controlling members 1 and the reflecting surface 24 are arranged to face each other so as to be orthogonal to the OA. The optical sheet 27 diffuses incident light from the rear (right side in FIG. 11) and forwards it. As the optical sheet 27, a diffusion plate, a diffusion sheet, a prism sheet, DBEF (manufactured by 3M) or the like may be used.

  According to the surface light source device 16 having such a configuration, the light emitted from each light emitting element 3 is controlled in the traveling direction by the corresponding light beam control member 1, and is laterally (Y) from each light beam control member 1. (Axial direction) Then, the light of each light emitting element 3 emitted from each light flux controlling member 1 in this way is reflected toward the optical sheet 27 of the surface light source device 16 on the inclined reflecting surface 24a as the reflecting means, and then the optical sheet. 27 is emitted forward. At this time, the luminance distribution of each light flux controlling member 1 can be formed into a luminance distribution having a high degree of approximation to a rectangular shape elongated in the Y-axis direction. The synthesized in-plane luminance distribution can be made highly uniform with sufficiently reduced light overlap (interference) between the light flux controlling members 1 adjacent to each other.

(Second form)
Next, FIG. 12 is a plan view showing the surface light source device 16 of the second embodiment.

  As shown in FIG. 12, the surface light source device 16 of the present embodiment is different from the first embodiment in that the light emitting element 3 and the light flux controlling member 1 are not arranged in a row as in the first embodiment, but in a staggered manner. The points are arranged in columns.

  As shown in FIG. 12, in this embodiment, the positions of the light flux controlling members 1 in the X direction are offset from each other between the rows of the light flux controlling members 1, so that the Y-axis direction obtained in one row is obtained. It is possible to prevent the luminance distribution of the long luminous flux control member 1 from greatly overlapping the luminance distribution of the luminous flux control member 1 elongated in the Y-axis direction obtained in the other row. Therefore, it is possible to realize a highly uniform in-plane luminance distribution in which light overlap (interference) between the light flux controlling members 1 adjacent to each other in the X-axis direction and the Y-axis direction is sufficiently relaxed.

(Third form)
Next, FIG. 13 is a plan view showing the surface light source device 16 of the third embodiment, and FIG. 14 is a cross-sectional view taken along line AA of FIG.

  As shown in FIG. 13, in the surface light source device 16 of this embodiment, the light emitting elements 3 and the light flux controlling members 1 are not arranged in a single line along the longitudinal direction of the housing 17 as in the first embodiment. Instead, two rows are arranged along the short direction (up and down) of the casing 17 so as to be spaced apart in the longitudinal direction (left and right) of the casing 17. In other words, in this embodiment, the rows of light flux controlling members 1 (light emitting devices 4) aligned with a predetermined alignment interval in the X-axis direction are arranged in two rows in parallel with a predetermined alignment interval in the Y-axis direction. ing. However, the alignment interval in the Y-axis direction is much larger than the alignment interval in the X-axis direction.

  In addition, as shown in FIGS. 13 and 14, in this embodiment, the bottom surface 18 is not single as in the first embodiment, but corresponds to the left and right two rows of light flux control members 1. It is divided in two. As shown in FIG. 14, in this embodiment, the upper and lower side surfaces 21 and 22 of the housing 17 are not inclined reflecting surfaces 24a as in the first embodiment. The side surfaces 19 and 20 are inclined reflecting surfaces 24a. Further, in FIGS. 13 and 14, in the present embodiment, a pair of inclined reflecting surfaces 24a (hereinafter referred to as the isosceles triangles) connected to each other at the center position in the longitudinal direction of the casing 17 that is the division position of the bottom surface 18. A central inclined reflecting surface). Of the pair of central inclined reflecting surfaces 24a, the left central inclined reflecting surface 24a in FIG. 14 is mainly the reflection of the emitted light from the light flux controlling member 1 on the left column side together with the inclined reflecting surface 24a on the left side surface 19. It comes to function as a surface. On the other hand, the central inclined reflecting surface 24a on the right side in FIG. 14 functions mainly as a reflecting surface for outgoing light from the light flux controlling member 1 on the right column side, together with the inclined reflecting surface 24a on the right side surface 20. . Note that the height of the central inclined reflection surface 24a is the same as the height of the inclined reflection surface 24a on the left and right side surfaces 19 and 20.

  According to this embodiment, the luminance distribution of each light flux controlling member 1 having a good approximation degree to the rectangular shape can be spread evenly in the plane while avoiding the influence of interference, so that the uniformity of the in-plane luminance distribution is improved. Furthermore, it can improve efficiently.

(4th form)
Next, FIG. 15 is a cross-sectional view showing a surface light source device 16 of a fourth form.

  As shown in FIG. 15, the surface light source device 16 of the present embodiment is different from the third embodiment in that the central inclined surface reflecting surface 24 a is higher than the inclined reflecting surfaces 24 a on the left and right side surfaces 19 and 20. The difference is that it is formed low.

  According to this embodiment, since the amount of reflected light on the central inclined reflecting surface 24a is reduced, the luminance directly above the central inclined reflecting surface 24a can be relaxed.

(5th form)
Next, FIG. 16 is a plan view showing the surface light source device 16 of the fifth embodiment, and FIG. 17 is a cross-sectional view taken along line AA of FIG.

  As shown in FIGS. 16 and 17, the surface light source device 16 of the present embodiment is such that the central inclined reflection surface 24 a is removed from the third embodiment, and the bottom surface 18 is united accordingly. The point is different.

  In the present embodiment, the central luminance is slightly reduced by the absence of the central inclined reflection surface 24a. On the other hand, the light emitted from the light beam control member 1 on the left column side is emitted on the right side surface 20. In addition, the in-plane brightness can be reflected by the inclined reflection surface 24a on the left side surface 19 and the light emitted from the light beam control member 1 on the right column side to the left side can be reflected by the inclined reflection surface 24a. The luminance at the left and right ends of the distribution can be raised.

  Next, as an embodiment of the present invention, the influence of the characteristic components of the light flux controlling member of the present invention on the luminance distribution will be described using specific simulation results. In this description, the simulation results for the conventional light flux controlling member 1 ′ shown in FIGS. 18 to 21 are used as a comparative example as necessary. 18 is a front view of a conventional light flux controlling member 1 ′, FIG. 19 is a plan view of FIG. 18, FIG. 20 is a left side view of FIG. 18, and FIG. 21 is a bottom view of FIG.

(1) Effect of Second Total Reflection Surface on Luminance Distribution First, in this embodiment, the second total reflection surface as one of the characteristic components of the light flux controlling member of the present invention has luminance distribution. A simulation was conducted to verify the effect.

  The light flux controlling member of the present invention used for this item satisfies the following conditions (a) to (e).

(A) Width in the X-axis direction (maximum width): 7 mm
(B) Curve of the second total reflection surface: Yes (however, it is a concave R surface having no curvature in the optical axis direction and having a curvature in plan view, and the center of curvature is on the first virtual plane) (It is a concave R surface with a radius of curvature of 45 mm.)
(C) Radiation of exit surface: None (plane)
(D) Groove portion of light emitting element facing surface: None (plane)
(E) Reflective sheet (reflective surface): None

Also, in this item, a conventional light flux controlling member was also used as a comparative example, but the conditions for this were the same as those of the light flux controlling member of the present invention except for (b). The condition was satisfied.
(B ′) Curve of the second total reflection surface: None (plane)

  Further, in this simulation, a top view LED as a light emitting element is disposed at a distance of 0.5 mm from the incident surface in the direction of the optical axis OA in both the light flux control member of the present invention and the conventional light flux control member. In this simulation, it is assumed that the optical sheet is disposed above the light flux controlling member, and the luminance distribution of the light immediately after passing through the optical sheet is obtained.

  Under such conditions, the simulation result of the luminance distribution obtained by controlling the traveling direction of the light emitted from the LED by the light flux controlling member is shown in FIG. 22 for the light flux controlling member of the present invention. The case of the control member is shown in FIG.

Here, before the specific evaluation, first, the outline of the simulation results shown in FIG. 22 and FIG. 23 will be described. In each figure, as the simulation result, the region with higher luminance [cd / mm ² ] is shown. The luminance distribution in which the tone becomes dark is shown. The luminance corresponding to the tone of each area is as shown in FIG. Each numerical value shown on the right side of the luminance distribution in each figure is a position [mm] in the Y-axis direction with the optical axis of the light flux controlling member (in other words, the light emission center of the LED) as the origin. On the other hand, each numerical value shown on the lower side of the luminance distribution in each figure is a position [mm] in the X-axis direction with the optical axis of the light flux controlling member as the origin.

  Then, considering the simulation results, as shown in FIG. 22, when the light flux controlling member of the present invention is used, the high luminance region recognized as the bright portion is relatively small and the width in the X-axis direction (see FIG. 22). It can be seen that a luminance distribution close to a rectangular shape in which the dimension in the arrow direction in FIG.

  On the other hand, as shown in FIG. 23, when the conventional light flux controlling member is used, the luminances of the two regions in the vicinity of both outer sides in the Y-axis direction with respect to immediately above the light flux controlling member are mainly. It can be seen that a luminance distribution can be obtained that is higher than the surrounding area over a wide range and shows an arcuate (fan-shaped) distribution spread that greatly deviates from the rectangular shape in the X-axis direction.

  In other words, according to the simulation results, the configuration of the second total reflection surface unique to the present invention reduces the unevenness of brightness in the light flux control member alone and the degree of approximation to the rectangular shape of the brightness distribution of the light flux control member alone. It has been demonstrated that it can contribute to improvement.

(2) Influence of Exit Surface on Luminance Distribution Next, in this embodiment, a simulation for verifying the influence of the exit surface on the brightness distribution as one of the characteristic components of the light flux controlling member of the present invention is performed. went.

  The light flux controlling member of the present invention used for this simulation is assumed to satisfy the following conditions in addition to the conditions (a), (b), (d) and (e) described above.

(C ′) Curvature of exit surface: Existence (however, it is a convex R surface having a curvature in the optical axis direction and no curvature in plan view, and having a curvature radius of 12.89 mm). )
Other simulation conditions are the same as in item (1).

  The result of this simulation is shown in FIG. The outline of the simulation result is as already described in the item (1).

  As shown in FIG. 24, in the case where the total reflection surface is formed on the convex R surface, the luminance distribution is increased as compared with the case where the second total reflection surface is only formed on the concave R surface (in the case of FIG. 22). It can be seen that it is expanded toward the Y-axis direction.

  That is, according to the simulation results, it has been proved that the configuration of the emission surface unique to the present invention can contribute to uniform luminance over a wide range and the reduction in the number of LED lamps.

(3) Influence of Groove of Light Emitting Element Opposing Surface on Luminance Distribution Next, in this embodiment, the groove of the light emitting element facing surface is one of the characteristic components of the light flux controlling member of the present invention. A simulation was conducted to verify the effects on the environment.

  The light flux controlling member of the present invention used for this simulation is assumed to satisfy the following conditions in addition to the above-mentioned conditions (a), (b), (c ′) and (e).

(D ′) Groove portion of light emitting element facing surface portion: Existence (however, tilt angle θ1 = 20 ° of first tilted surface, tilt angle θ2 = 80 ° of second tilted surface, width in Y-axis direction = 2 mm, high (S = 0.7mm)
Other simulation conditions are the same as in item (1).

  The result of this simulation is shown in FIG. The outline of the simulation result is as already described in the item (1).

  As shown in FIG. 25, in the case where the groove portion of the light emitting element facing surface portion is provided, the second total reflection surface is formed on the concave R surface and the total reflection surface is simply formed on the convex R surface (in FIG. 24). It can be seen that the luminance in the vicinity immediately above the LED (inside the broken line in FIG. 25) can be reduced as compared with the case of FIG.

  That is, according to the simulation result, it was proved that the configuration of the groove part unique to the present invention can contribute to the reduction of the luminance immediately above the light source.

Also, in this item, only the condition (a) is replaced with the following condition for each of the conditions (a), (b), (c ′), (d ′) and (e) corresponding to FIG. And simulated.
(A ′) X-axis direction width (maximum width): 9 mm
The result of this simulation is shown in FIG.

Furthermore, in this item, for each condition corresponding to FIG. 25, a simulation was performed by replacing only the condition (a) with the following condition.
(A ″) X-axis direction width (maximum width): 11 mm
The result of this simulation is shown in FIG.

  Comparing FIGS. 25 to 27, it can be seen that as the width of the light flux controlling member in the X-axis direction is narrower, a luminance distribution having a better approximation to a rectangular shape can be obtained.

(4) Effect of Reflection Sheet (Reflection Surface) on Luminance Distribution Next, as one of the characteristic components of the light flux controlling member of the present invention, the reflection sheet combined with the second total reflection surface has the luminance distribution. A simulation was conducted to verify the effect.

The light flux controlling member of the present invention used for this simulation is assumed to satisfy the following conditions in addition to the above-mentioned conditions (a), (b), (c) and (d).
(E ′) Reflective sheet (reflective surface): Existence The result of this simulation is shown in FIG.

  As shown in FIG. 28, when the reflection sheet is used, it can be seen that a bright luminance distribution with high uniformity can be obtained by expanding the high luminance region into a rectangular shape.

(5) Influence on In-Plane Brightness Distribution Next, a simulation for verifying the influence on the in-plane brightness distribution when the best mode light flux controlling members of the present invention are arranged in a line as shown in FIGS. went.

The light flux controlling member in the best mode satisfies the conditions (a), (b), (c ′), (d ′) and (e ′).
The result of this simulation is shown in FIG.

Further, in this item, as a first comparative example, the same simulation as in FIG. 29 was performed for a configuration that satisfied only (e ′) and did not have a light flux controlling member (only LEDs were arranged). .
The result of this simulation is shown in FIG.

Further, in this item, as a second comparative example, the same simulation as in the case of FIG. 29 was performed on the configuration in which the conventional light flux controlling members shown in FIGS.
The result of this simulation is shown in FIG.

  As can be seen from a comparison of FIGS. 29 to 31, when the light flux controlling member of the present invention is applied to a surface light source, light can be evenly distributed in the surface and the brightness becomes locally significant. In-plane luminance distribution with high uniformity can be realized.

  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.

  For example, by optimizing the total reflection direction of light on the second total reflection surfaces 8F and 8R by changing the curvature radii of the second total reflection surfaces 8F and 8R having a concave curved surface according to the position. Also good. Similarly, optimization of the light emission direction on the emission surfaces 7L and 7R may be aimed at by changing the curvature radii of the convex curved surface emission surfaces 7L and 7R according to the position.

  In addition, the first total reflection surface and the second total reflection surface in the present invention totally reflect main light rays incident on the surfaces (particularly, light emitted from the intersection between the light emitting surface of the light emitting element and the optical axis). In other words, all light incident on the inside is not totally reflected. Since the light-emitting portion of the light-emitting element has an area instead of a point, it is difficult to totally reflect all light rays, so that there may be light that leaks slightly.

DESCRIPTION OF SYMBOLS 1 Light flux control member 2 Light emitting element opposing surface part 3 Light emitting element 5 Anti-light emitting element opposing surface part 7 1st side part (total reflection surface)
8 Second side surface (second total reflection surface)
10 Incident plane 11 Concave portion 12 First total reflection surface

Claims (10)

A light flux controlling member for controlling the traveling direction of light emitted from the light emitting element,
A predetermined direction orthogonal to the optical axis direction is a first direction, a direction orthogonal to both the first direction and the optical axis is a second direction, and the optical axis is orthogonal to the first direction. When the plane including the first virtual plane, and the plane perpendicular to the second direction and including the optical axis is the second virtual plane,
A light-emitting element facing surface portion that is formed in a length in the first direction, is disposed to face the light-emitting element, and is located on the back side of the light flux controlling member;
On the surface side that is opposite to the light emitting element facing surface portion, an anti-light emitting element facing surface portion that is formed long in the first direction;
A pair of first side surfaces respectively extending from both end portions in the first direction of the anti-light emitting element facing surface portion toward both end portions in the first direction of the light emitting element facing surface portion;
The anti-light emitting element facing surface portion extends from both end portions in the second direction toward the both end portions side of the light emitting element facing surface portion in the second direction, and the pair of first side surface portions A pair of second side surfaces respectively connected to both end portions in the second direction,
The light emitting element facing surface portion is
It is formed over a predetermined range in a direction orthogonal to the optical axis, and has an incident surface on which light emitted from the light emitting element is incident,
The anti-light emitting element facing surface portion is
Having a recess in which a valley bottom is formed at a position intersecting the first virtual plane;
The recess is
A first total reflection surface that totally reflects light of the light emitting element that has reached from the incident surface toward the pair of first side surface portions;
The first total reflection surface is:
It is formed in a shape in which the distance from the first virtual plane gradually increases as it goes away from the light emitting element with the valley bottom as a base point,
The pair of second side portions is
A second total reflection surface that totally reflects light of the light emitting element that has arrived from the incident surface toward the pair of first side surface portions and the first total reflection surface;
The pair of first side portions is
The light from the light-emitting element that has been formed in a shape in which the distance from the first virtual plane gradually decreases from the back surface side toward the front surface side and propagates through the light flux controlling member is reflected in the first direction. Each having an emission surface that emits in a direction away from the first virtual plane,
The pair of second total reflection surfaces is:
The light flux controlling member, wherein the light flux controlling member is formed to be curved so that a distance from the second virtual plane gradually decreases from the first side surface side toward the first virtual plane side. 2. The light flux controlling member according to claim 1, wherein the emission surface is formed to have a convex shape in the second virtual plane or a cross section parallel to the second virtual plane. A plurality of the light emitting element facing surface portions are formed so as to be aligned in the first direction outside the direction perpendicular to the optical axis with respect to the incident surface with the optical axis as a center. The light flux controlling member according to claim 1, further comprising a groove portion having a wedge shape in a parallel cross section. The light flux controlling member according to any one of claims 1 to 3, wherein the second total reflection surface is formed as a concave R surface having a predetermined radius of curvature. 5. The light flux controlling member according to claim 1, wherein the exit surface is formed on a convex R surface having a predetermined radius of curvature. The first total reflection surface and the emission surface are:
Formed in a plane-symmetric shape with the first virtual plane as a plane of symmetry;
The second total reflection surface is
The light flux controlling member according to any one of claims 1 to 5, wherein the light flux controlling member is formed in a plane-symmetrical shape with the second virtual plane as a plane of symmetry. The first total reflection surface has an angle formed by a tangent line at an arbitrary point on the second virtual plane or a cross section parallel to the second virtual plane and the first virtual plane. The light flux controlling member according to claim 1, wherein the light flux controlling member is formed in a shape that gradually increases so as to approach a right angle as the distance from the imaginary plane increases. A light-emitting device comprising the light flux controlling member according to claim 1 and a light-emitting element. A plurality of light-emitting devices according to claim 8 are arranged in a line at a predetermined interval in the second direction according to claim 1,
Reflective means for reflecting the emitted light from the emission surfaces of the plurality of light flux controlling members at a position on the first direction side according to claim 1 with respect to the plurality of light emitting devices ,
An optical sheet is provided so as to face each of the light flux controlling members and the reflecting means so as to be orthogonal to the optical axis of each of the light flux controlling members, and to emit incident light from the reflecting means. Surface light source device. The rows of light emitting devices along the second direction are arranged in parallel in the first direction with a predetermined interval larger than the alignment interval in the second direction. The surface light source device according to claim 9.