JP5392481B2 - Lighting device - Google Patents

Description

  The present invention relates to a lighting device.

  Conventionally, an illumination device using a light emitting diode element as a light source as a light emitting element is configured so that an arbitrary light distribution characteristic can be obtained by combining the light emitting diode element and a lens that controls light emitted from the light emitting diode element. Yes. For example, a bullet-type LED package is known as a light-emitting diode that places importance on the light collecting property. In this type of light emitting diode, a concave portion is provided on the top of one lead frame, and the light emitting diode element is placed and fixed on the concave portion, and the top of the light emitting diode element and the other lead frame are connected by a bonding wire. The periphery of the object is sealed with a translucent resin body. The concave portion provided at the top of the lead frame effectively guides the light emitted from the light emitting diode element upward, and the top of the translucent resin body is formed in a hemispherical shape, so that the light collecting effect is achieved. There was also an increased advantage.

  There is also known a surface-mounted LED in which an LED chip is mounted in a cavity molded with ceramic or resin, and a resin such as epoxy or silicone is sealed in the cavity. Some of these products have the function of a reflector (reflector) by expanding the surface inside the cavity upward in a tapered shape, and there are also products with improved directivity. In addition, there is a type in which directivity is further improved by attaching a lens made of glass or the like in addition to epoxy or silicone resin.

  In many cases, the above-mentioned light distribution characteristics are symmetrically arranged with respect to the optical axis. However, there are cases where an asymmetric light distribution characteristic with respect to the optical axis is desired, such as a traffic light. The traffic light is designed to distribute light in a relatively narrow range in order to ensure a certain brightness, so there is a problem that it looks extremely dark when the traffic light is viewed from a position outside the light distribution range outside the optical axis. is there. For example, road traffic lights are often installed at high positions in front of pedestrians and automobile drivers, but the lights of road traffic lights become darker as they approach the road traffic lights with the optical axis set parallel to the road surface. The traffic light itself is tilted so that the optical axis is slightly downward. However, if the optical axis is tilted too far downward, there is a problem that it becomes dark and difficult to see when viewed from a distance. For this reason, there has been proposed a traffic light intended to cause bias in the light distribution characteristics (see, for example, Patent Document 1).

  In addition, there is a need for a strobe device to make the irradiation range as far as possible from a macro (close range) (for example, 30 cm). In general, the strobe device has a problem that the entire optical area of the macro region cannot be irradiated because the optical axis at the center of the irradiation range of the strobe light and the optical axis of the photographing lens are shifted in parallel. However, because of the camera design, it is difficult to tilt the strobe device, and in this case as well, it is desired that the light distribution characteristics be biased. In addition to this, it is considered that there is a need to uniformly irradiate a portion that is tilted away from the optical axis due to design such as display illumination. In addition, when used for a sensor or the like, there is a need to collect light at a specific place.

JP-A-6-349307

  As described above, various light distribution characteristics are desired in the world. However, in order to have a desired light distribution characteristic, a complicated lens shape such as a Fresnel lens is often used as in the invention described in Patent Document 1, and there is a problem that manufacturing is not easy and cost is high. there were.

  The present invention has been made in view of such problems, and provides an illumination device capable of realizing desired light distribution characteristics without loss of light flux using a lens that is easy to manufacture with a simple configuration. For the purpose.

を満足するように構成される。
また、第２の本発明に係る照明装置は、光源と、この光源を被覆し当該光源からの光を所定方向に屈折させるレンズ部と、を有する照明部により構成され、レンズ部は、光源側に位置し、少なくとも一部が、光源の中心に球心が位置する球面として形成された入射面と、入射面を挟んで光源と反対側に位置し、少なくとも一部が、入射面の球心位置とは異なる位置を中心とする少なくとも１つ以上のコーニック面として形成された射出面と、を有し、射出面の形状が球面であった場合、光源の中心位置を原点とし、光源の載置面に対して水平方向で、かつ、当該射出面の球心と入射面の球心とを含む光源の載置面に対して垂直な面に平行な方向をＸ方向とし、載置面に対して法線方向をＺ方向とし、入射面の球心の位置座標をＡ（Ｘａ，Ｚａ）とし、射出面の球面の球心の位置座標をＢ（Ｘｂ，Ｚｂ）とし、射出面の球面の半径をｒｂとし、レンズ部の媒質の屈折率をｎとしたときに、次式

を満足するよう構成される。 In order to solve the above-mentioned problem, the illumination device according to the first aspect of the present invention is configured by an illumination unit including a light source and a lens unit that covers the light source and refracts light from the light source in a predetermined direction. The lens unit is located on the light source side, and at least a part thereof is located on the opposite side of the light source with the incident surface formed as a spherical surface with a spherical center located at the center of the light source, and at least a part of the lens unit. , have a, and the exit surface is a convex surface which is formed as at least one conic surface around the position different from the sphere center position of the incident surface, the conic surface of the exit surface, the center position of the light source The X direction is a direction parallel to a plane perpendicular to the mounting surface of the light source including the center of the emission surface and the spherical center of the incident surface, which is the origin, and is horizontal to the mounting surface of the light source The normal direction to the mounting surface is the Z direction, and the sphere of the incident surface Is the intersection of a line perpendicular to a tangent line having a contact point at an arbitrary position coordinate C (Xc, Zc) on the exit surface and an arbitrary straight line passing through the position coordinate A. The position coordinate is D (Xd, Zd), the position coordinate of the center of the exit surface is B (Xb, Zb), the long radius of the conic surface is a, the short radius is b, and a straight line passing through the center of the exit surface and X When the angle with the axis is θ and the refractive index of the lens medium is n, the following equation

It is configured to satisfy
Moreover, the illumination device according to the second aspect of the present invention includes an illumination unit that includes a light source and a lens unit that covers the light source and refracts light from the light source in a predetermined direction. At least a part of the incident surface formed as a spherical surface with the sphere centered at the center of the light source, and the opposite side of the light source across the incident surface, and at least a part of the sphere center of the incident surface And an emission surface formed as at least one conic surface centered at a position different from the position, and the shape of the emission surface is a spherical surface, the center position of the light source is set as the origin, and the light source is mounted. A direction parallel to the plane perpendicular to the mounting surface of the light source including the sphere center of the emission surface and the sphere center of the incident surface is defined as the X direction, On the other hand, the normal direction is the Z direction, and the position coordinates of the sphere center of the incident surface are A (Xa, Za And then, the position coordinates of the sphere center of the spherical exit surface B (Xb, Zb) and the radius of the spherical surface of the exit surface and rb, the refractive index of the medium of lens portions is n, the following equation

Configured to satisfy.

  In such an illuminating device, it is preferable that the center of each conic surface of the exit surface is located in the space of a sphere that partially constitutes the spherical surface of the entrance surface.

  In such an illuminating device, the exit surface is preferably composed of two or more conic surfaces and a semi-conical truncated cone or a semi-cylinder that connects the two or more conic surfaces.

  Such an illuminating device preferably includes a plurality of illumination units, and these illumination units are arranged at equal intervals.

  When the lighting device according to the present invention is configured as described above, a lighting device capable of realizing a desired light distribution characteristic without loss of light flux can be obtained using a lens that can be easily manufactured with a simple configuration. .

It is a top view of the illuminating device of 1st Example of this invention. It is the II-II sectional view taken on the line of FIG. It is the III-III sectional view taken on the line of FIG. 1, and is explanatory drawing for demonstrating an optical path when the exit surface of the illuminating device in 1st Example is made into a conic surface. It is the III-III sectional view taken on the line of FIG. 1, and is explanatory drawing for demonstrating an optical path when the exit surface of the illuminating device in 1st Example is made into the spherical surface. It is a figure which shows the simulation result about the radiation angle characteristic of the light beam inject | emitted from the lens part in 1st Example. It is a figure which shows the radiation angle characteristic of surface mounted package LED used for the light source of 1st Example. It is a top view of the illuminating device of 2nd Example of this invention. It is a figure which shows the simulation result about the incident radiation angle characteristic inject | emitted from the lens part in 2nd Example. It is a top view of the illuminating device of 3rd Example of this invention. FIG. 10 is a sectional view taken along line XX in FIG. 9. It is a figure which shows the simulation result about the radiation angle characteristic of the light beam inject | emitted from the lens part of 3rd Example. It is a top view of the illuminating device of 4th Example of this invention. It is a figure which shows the simulation result about the radiation angle characteristic of the light beam inject | emitted from the lens part of 4th Example. It is a top view of the illuminating device of 5th Example of this invention. It is the XV-XV sectional view taken on the line of FIG. It is a figure which shows the simulation result about the radiation angle characteristic of the light beam inject | emitted from the lens part of 5th Example. It is a top view of the illuminating device of 6th Example of this invention. It is a figure which shows the simulation result about the radiation angle characteristic of the light beam inject | emitted from the lens part of 6th Example. It is a top view of the illuminating device of 7th Example of this invention. It is the XX-XX sectional view taken on the line of FIG. It is a figure which shows the simulation result about the radiation angle characteristic of the light beam inject | emitted from the lens part of 7th Example. It is a top view of the illuminating device of 8th Example of this invention. It is a figure which shows the simulation result about the radiation angle characteristic of the light beam inject | emitted from the lens part of 8th Example.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the illumination device 10 according to the present embodiment includes a package substrate 2, an LED chip 3 as a light source mounted on the package substrate 2, and a lens unit 4 formed to cover the LED chip 3. (Package substrate 2, LED chip 3 and lens unit 4 are collectively referred to as "illumination unit 1").

  In this specification, the X direction means the surface of the package substrate 2 (the mounting surface of the LED chip 3 as the light source) as shown in FIG. 3 or FIG. 4 representing the cross section taken along the line III-III shown in FIG. Is a direction parallel to the surface perpendicular to the surface of the package substrate 2 including the spherical center of the entrance surface 4a and the center of the exit surface 4b, and the Z direction refers to FIG. As shown in FIG. 4, the normal line direction with respect to the package substrate 2 is indicated. Although not shown, the Y direction is a horizontal direction with respect to the package substrate 2 and indicates a direction orthogonal to the X direction. In the following description, the LED chip 3 is considered as a point light source located at the center of the LED chip 3, and this point light source is the center of coordinates (the optical axis coincides with the Z-axis direction).

  On the other hand, as a direction determination for expressing the light distribution characteristics of the lighting device 10, as shown in FIG. 1, the direction is the horizontal direction with respect to the surface of the package substrate 2 and the short direction of the package substrate 2. Is defined as the X ′ direction, and the longitudinal direction is defined as the Y ′ direction. 2 is a cross-sectional view taken along line II-II shown in FIG.

  The incident surface 4a of the lens unit 4 is formed as a concave surface facing the light source, and is arranged so that the spherical center position coincides with the position of the point light source (the center of the LED chip 3) so that total reflection does not occur. It is a spherical surface. If total reflection occurs on the incident surface 4a, the amount of light is reduced, and the intended light distribution characteristic cannot be obtained. Therefore, the incident surface 4a has such a configuration. In order to prevent a decrease in the amount of light, the radius of the incident surface 4a needs to be large enough to capture the divergence angle of the light beam emitted from the LED chip 3.

  On the other hand, the exit surface 4b on the surface opposite to the LED chip 3 across the entrance surface 4a is formed as a convex surface made of one conic surface formed so as to cover the entrance surface 4a. The exit surface 4b is configured such that its center position is different from the spherical center position of the incident surface 4a, and is closer to the origin (inside the spherical surface) than the spherical surface of the incident surface 4a. ing. Thus, desired light distribution characteristics can be obtained by setting the spherical center of the entrance surface 4a and the center of the exit surface 4b to different positions.

  In the present embodiment, the entire incident surface 4a and exit surface 4b do not necessarily have to be a conic surface, and at least a part of the entrance surface 4a and the exit surface 4b may be a conic surface. For example, a combination of a conic surface and a flat surface may be used. Further, the conic surface of the exit surface 4b may be one or a combination of two or more. Moreover, you may connect between conic surfaces by a semi-conical truncated cone or a half cylinder so that two or more conic surfaces may connect smoothly, for example.

  In such an illuminating device 10, when total reflection occurs on the exit surface 4 b as with the incident surface 4 a, the totally reflected light is reflected by the package substrate 2 and the like, and a desired light distribution characteristic cannot be obtained. Therefore, in order to prevent total reflection from occurring on the exit surface 4b, the exit surface 4b has a point light source position (center position of the LED chip 3) as an origin, as shown in FIG. Arbitrary straight line passing through the position coordinate A and a line perpendicular to the tangent with the position coordinate C (Xc, Zc) on the exit surface 4b as a contact point, where the position coordinate of the sphere center A is A (Xa, Za). The position coordinate of the intersection point with D is X (Xd, Zd), the position coordinate of the center of the exit surface 4b is B (Xb, Zb), the major radius of the conic surface is a, the minor radius is b, and the center of the exit surface 4b It is preferable to satisfy the following expression (1) where θ is an angle formed by a straight line passing through x and the x axis, and n is a refractive index of the medium of the lens unit 4. In addition, when the emission surface 4b has two or more spherical surfaces, it is preferable that each conic surface satisfies the following formula (1). In the following description, the refractive index is with respect to the reference wavelength.

  The above formula (1) can be derived as follows. That is, as shown in FIG. 3, when the light from the LED chip 3 is emitted from the point C, the angle between the line segment AC connecting the sphere centers A and C and the X axis is θ1, the point D and the C The angle formed by the straight line DC connecting the point and the X axis is θ3, the angle formed by the straight line AD connecting the ball center A and the point D and the X axis is θ4, and the line segment connecting the line segment AC, the D point, and the C point. When the angle formed by DC is θ2, the long axis of the exit surface 4b is a, the short axis is b, and the angle between the straight line passing through the center of the exit surface 4b and the X axis is θ, the following equation (2 ) Is derived.

  Further, from Snell's law, the following equation (3) holds. In formula (3), 1 indicates total reflection.

  Then, by substituting equation (2) into equation (3), the above equation (1) is derived.

  In particular, when the emission surface 4b is formed using a spherical surface, the following equation may be used. That is, as shown in FIG. 4, the exit surface 4b has the point light source position (the center position of the LED chip 3) as the origin, the position coordinates of the sphere center A of the entrance surface 4a as A (Xa, Za), and the exit surface. When the position coordinate of the spherical center B of one spherical surface in 4b is B (Xb, Zb), the radius of the exit surface 4b is rb, and the refractive index of the medium forming the lens unit 4 is n, the following equation It is preferable to satisfy (4). In addition, when the emission surface 4b has two or more spherical surfaces, it is preferable that the spherical center of each spherical surface satisfies the following expression (4).

  The above equation (4) can be derived as follows. That is, as shown in FIG. 4, when the light from the LED chip 3 is emitted from the point C, a line segment AC connecting the sphere centers A and C and a line segment AB connecting the sphere centers A and B are shown. The angle between the line segment AC and the line segment BC connecting the ball centers B and C is θ2, the angle of the exit surface 4b is rb, and the angle between the ball centers A and B is θ1. When the distance is AB with a bar, the following equation (5) is derived by the sine theorem.

  Further, the following equation (6) holds according to Snell's law. In the formula (6), 1 indicates total reflection.

  Then, the above formula (4) is derived by substituting AB with a bar shown in formula (7) into the calculation formula in which formula (6) is substituted into formula (5).

  The illumination device 10 according to the present embodiment is configured as described above. When a driving voltage is applied to the LED chip 3, the LED chip 3 emits light, and light from the LED chip 3 passes through the lens unit 4. Inject outside. At that time, the light incident on the incident surface 4a (spherical surface) having the negative lens function of the lens unit 4 is diffused, and the diffused light is condensed by the exit surface 4b (conic surface) having the positive lens function, and is desired. The light is emitted to the outside in a state where the light distribution characteristics are obtained. Thus, since a desired light distribution characteristic is acquired, the illuminating device 10 useful for a traffic light, a sensor, etc. is obtained.

[First embodiment]
Embodiments of the present invention will be described below with reference to the accompanying drawings. 1-4 is a figure which shows the structure of the illuminating device 10 which concerns on 1st Example. The illuminating device 10 of 1st Example is comprised from the illumination part 1 which consists of the package substrate 2, the light source 3, and the lens part 4, and the lens part 4 has the entrance plane 4a which has a negative lens function, and a positive lens function. It is comprised from the injection surface 4b which has. The radius of curvature of the incident surface 4a is r = 1.8 mm, the long radius of the exit surface 4b is a spherical surface with a = 3.3 mm, and the short radius is b = 3.3 mm. Further, the position of the spherical center A of the entrance surface 4a is the center position of the light source 3, and the position of the center B of the exit surface 4b is 1 mm from the center of the light source 3 in the X 'direction and the Y' direction as shown in FIG. Moved by -1 mm. Note that the coordinates in the Z direction are the same for both the ball center A and the center B. As described above, in the first embodiment and the following embodiments, the coordinate in the Z direction of the center B of the exit surface 4b is the same as the sphere center A of the entrance surface 4a, but is not necessarily the same. And the coordinates of the sphere center A in the Z direction may be different from each other. However, the center B is preferably located in the space of a sphere including the spherical surface of the incident surface 4a.

  FIG. 5 shows a simulation result of the radiation angle characteristic in the X ′ direction and the Y ′ direction of the light beam emitted from the lens unit 4 in the first embodiment. In the first embodiment, a surface mount package LED is used as the light source 3. FIG. 6 shows the radiation angle characteristics in the X ′ direction and Y ′ direction of this surface-mount package LED. Further, a material having a refractive index n = 1.525 is used for the lens unit 4. Note that 0 (deg) is the optical axis direction (Z-axis direction), and the same applies to the drawings showing the radiation angle characteristics.

  By substituting the above numerical values into the above formula (1) or (4), it is understood that total reflection does not occur under this condition. Compared with the radiation angle characteristics of the surface-mount package LED of FIG. 6, in the illumination device 10 of the first embodiment, as shown in FIG. 5, 45 in the X ′ direction from the exit surface 4b of the lens unit 4. The luminous flux can be emitted with a light distribution characteristic having a direction of −45 degrees in the Y ′ direction.

[Second Embodiment]
In FIG. 7, the structure of the illuminating device 10 which concerns on 2nd Example is shown. The illumination device 10 shown in FIG. 7 is configured by arranging a plurality of illumination units 1 in the first embodiment in an array. FIG. 8 shows a simulation result of the radiation angle characteristic in the X ′ direction and the Y ′ direction of the light beam emitted from the lens unit 4 in the second embodiment. By arranging in this way, in the second embodiment, it is also possible to increase the radiation intensity while maintaining the light distribution characteristics as obtained in the first embodiment.

[Third embodiment]
9 and 10 show the configuration of the illumination device 10 according to the third embodiment. This illuminating device 10 has the same configuration as that of the illuminating device 10 of the first embodiment, except that the shape of the exit surface 11 (11a to 11c) of the lens unit 4 is changed. The third embodiment is effective when it is desired to uniformly illuminate a surface perpendicular to the optical axis by arranging the exit surface 11 symmetrically with respect to the optical axis.

  The exit surface 11 of the lens unit 4 of the third embodiment has two spherical exit surfaces 11a and 11b having a positive lens function and the exit surfaces 11a and 11b, in order to smoothly connect them. It is formed from the inserted semi-cylindrical injection surface 11c. The positions of the centers B and B ′ of the exit surface 11a and the exit surface 11b are symmetric with respect to the optical axis (Z direction in FIG. 10), and the radius of curvature is the same. With such a configuration, the illumination device 10 of the third embodiment can obtain light distribution characteristics that are symmetrical with respect to the optical axis, as will be described later. The purpose of inserting the injection surface 11c is provided for ease of manufacturing.

  The illuminating device 10 in this 3rd Example is demonstrated concretely. In this illumination device 10, the radius of curvature of the entrance surface 4a is r = 1.8 mm, the major surface of the exit surface 11a is a spherical surface with a = 3 mm, the minor radius is b = 3 mm, and the major radius of the exit surface 11b is A spherical surface with a = 3 mm and a short radius of b = 3 mm. The spherical center A of the incident surface 4 a is the center position of the light source 3. The center B of the exit surface 11a is set to −0.5 mm from the light source 3 in the X ′ direction and 0 mm in the Y ′ direction, and the center B position of the exit surface 11b is set to 0.5 mm from the light source 3 in the X ′ direction. The position is 0 mm in the Y ′ direction. The injection surface 11c is inserted so that the conic surfaces of the injection surface 11a and the injection surface 11b are smoothly connected. The light source 3 used here is a surface-mounted package LED similar to that of the first embodiment. Further, the refractive index of the medium of the lens unit 4 is n = 1.525 as in the first embodiment.

  FIG. 11 shows a simulation result of the radiation angle characteristics in the X ′ direction and the Y ′ direction of the light beam emitted from the lens unit 4 in the third embodiment. Further, by substituting the above numerical values for the exit surfaces 11a and 11b into the above formula (1) or (4), it is understood that total reflection does not occur under this condition. Thus, in the illuminating device 10 of 3rd Example, the light distribution characteristic suitable for illuminating uniformly with respect to a surface perpendicular | vertical with respect to an optical axis is acquired. That is, a light beam having a direction of −30 degrees in the X ′ direction and 0 degree in the Y ′ direction from the exit surface 11 a of the lens unit 4, a direction of 30 degrees in the X ′ direction and 0 degree in the Y ′ direction from the exit surface 11 b. Can be emitted with a contrast intensity distribution with respect to the optical axis.

[Fourth embodiment]
FIG. 12 is a diagram illustrating a configuration of the illumination device 10 according to the fourth embodiment. The illumination device 10 shown in FIG. 12 is configured by arranging a plurality of illumination units 1 in the third embodiment in an array. FIG. 13 shows a simulation result of the radiation angle characteristics in the X ′ direction and the Y ′ direction of the light beam emitted from the lens unit 4 in the fourth embodiment. By arranging in this way, in the fourth embodiment, it is also possible to increase the radiation intensity while maintaining the light distribution characteristics as obtained in the third embodiment.

[Fifth embodiment]
14 and 15 show the configuration of the illumination device 10 according to the fifth embodiment. The illumination device 10 has the same configuration as the illumination device 10 of the first embodiment except that the shape of the exit surface 12 (12a to 12c) of the lens unit 4 is changed. In the fifth embodiment, when the exit surface 12 is asymmetrically arranged with respect to the optical axis, the light distribution characteristic is biased like a strobe, or the surface is inclined with respect to the optical axis. This is effective when it is desired to uniformly illuminate the light.

  The exit surface 12 of the lens unit 4 of the fifth embodiment is inserted between two spherical exit surfaces 12a and 12b having a positive lens function and the exit surfaces 12a and 12b in order to smoothly connect them. It is formed from a semi-conical trapezoidal exit surface 12c. By making the positions and the radii of curvature of the centers B and B ′ of the exit surface 12a and the exit surface 12b different from each other, the light distribution characteristic and the radiation intensity value can be changed. Further, the purpose of inserting the injection surface 12c is provided in order to make it easier to manufacture in the same manner as in the third embodiment.

  The illuminating device 10 in this 5th Example is demonstrated concretely. In this illumination device 10, the radius of curvature of the incident surface 4a is r = 1.8 mm, the major surface of the exit surface 12a is a spherical surface with a = 3 mm, the minor radius is b = 3 mm, and the major radius of the exit surface 12b is a = 3.3 mm and the short radius is a spherical surface with b = 3.3 mm. The spherical center A of the incident surface 4 a is the center position of the light source 3. Further, the center B of the exit surface 12a is −0.5 mm in the X ′ direction and 0 mm in the Y ′ direction from the light source 3, and the center B ′ of the exit surface 12b is 1.2 mm in the X ′ direction from the light source 3. , 0 mm in the Y ′ direction. The injection surface 12c is inserted such that the conic surfaces of the injection surface 12a and the injection surface 12b are smoothly connected. The light source 3 used here is a surface-mounted package LED similar to that of the first embodiment. Further, the refractive index of the medium of the lens unit 4 is n = 1.525 as in the first embodiment.

  FIG. 16 shows a simulation result of the radiation angle characteristics in the X ′ direction and the Y ′ direction of the light beam emitted from the lens unit 4 in the fifth example. Further, by substituting the above numerical values for the exit surfaces 12a and 12b into the above formula (1) or (4), it is understood that total reflection does not occur under this condition. As described above, the illumination device 10 of the fifth embodiment is suitable for the case where the light distribution characteristic is biased like a strobe, or for uniform illumination on a surface inclined with respect to the optical axis. Light distribution characteristics can be obtained. That is, a light beam having a direction of −45 degrees in the X ′ direction and 0 degree in the Y ′ direction from the exit surface 12 a of the lens unit 4, and a direction of 45 degrees in the X ′ direction and 0 degrees in the Y ′ direction from the exit surface 12 b. Can be emitted in a non-contrast intensity distribution with respect to the optical axis.

[Sixth embodiment]
In FIG. 17, the structure of the illuminating device 10 which concerns on 6th Example is shown. The illumination device 10 is configured by arranging a plurality of illumination units 1 in the fifth embodiment in an array. FIG. 18 shows a simulation result of the radiation angle characteristic in the X ′ direction and the Y ′ direction of the light beam emitted from the lens unit 4 in the sixth example. By arranging in this way, in the sixth embodiment, it is also possible to increase the radiation intensity while maintaining the light distribution characteristics as obtained in the fifth embodiment.

[Seventh embodiment]
19 and 20 show the configuration of the illumination device 10 according to the seventh embodiment. This illuminating device 10 has the same configuration as that of the illuminating device 10 of the first embodiment except that the shape of the exit surface 13 (13a to 13c) of the lens unit 4 is changed. In the seventh embodiment, as in the fifth embodiment, when the exit surface 13 is asymmetrically arranged with respect to the optical axis, the light distribution characteristic such as a strobe is to be biased. This is effective when, for example, it is desired to uniformly illuminate a surface that is inclined. The difference between the seventh embodiment and the fifth embodiment is that the shape of the exit surface is not a spherical surface but an aspherical surface. By changing the shape of the emission surface from a spherical surface to an aspherical surface, the shape can be smoothed, and there is an advantage that the manufacturing can be facilitated.

  The exit surface 13 of the lens unit 4 of the seventh embodiment has two conic surface exit surfaces 13a and 13b having a positive lens function, and the exit surfaces 13a and 13b are smoothly connected between them. It is formed from the inserted semi-conical trapezoidal exit surface 13c. Further, the purpose of inserting the injection surface 13c is provided to make it easier to manufacture in the same manner as in the third embodiment.

  The illuminating device 10 in this 7th Example is demonstrated concretely. In this illumination device 10, the radius of curvature of the entrance surface 4a is r = 1.8 mm, the major radius of the exit surface 13a is a = 4.1 mm, the minor radius is b = 4 mm, and the major radius of the exit surface 13b is a = 5.4 mm and the short radius is b = 4 mm. The spherical center A of the incident surface 4 a is the center position of the light source 3. Further, the center D of the exit surface 13a is -0.9 mm from the light source 3 in the X 'direction, 0 mm in the Y' direction, and -0.7 mm in the Z direction. To −0.4 mm in the X ′ direction, 0 mm in the Y ′ direction, and −0.9 mm in the Z direction. The injection surface 13c is inserted so that the spherical surfaces of the injection surface 13a and the injection surface 13b are smoothly connected. The light source 3 used here is a surface-mounted package LED similar to that of the first embodiment. Further, the refractive index of the medium of the lens unit 4 is n = 1.525 as in the first embodiment.

  FIG. 21 shows a simulation result of the radiation angle characteristics in the X ′ direction and the Y ′ direction of the light beam emitted from the lens unit 4 in the seventh example. Further, by substituting the above numerical values for the exit surfaces 13a and 13b into the above equation (1), it is understood that total reflection does not occur under this condition. As described above, the illumination device 10 according to the seventh embodiment is suitable for the case where the light distribution characteristic is biased like a strobe, or for uniform illumination on a surface inclined with respect to the optical axis. Light distribution characteristics can be obtained. That is, a light beam having a direction of −30 degrees in the X ′ direction and 0 degree in the Y ′ direction from the exit surface 13 a of the lens unit 4, a direction of 45 degrees in the X ′ direction and 0 direction in the Y ′ direction from the exit surface 13 b. Can be emitted in a non-contrast intensity distribution with respect to the optical axis.

[Eighth embodiment]
In FIG. 22, the structure of the illuminating device 10 which concerns on 8th Example is shown. This illuminating device 10 is configured by arranging a plurality of illumination units 1 in the seventh embodiment in an array. FIG. 23 shows a simulation result of the radiation angle characteristics in the X ′ direction and the Y ′ direction of the light beam emitted from the lens unit 4 in the eighth example. By arranging in this way, in the eighth embodiment, it is also possible to increase the radiation intensity while maintaining the light distribution characteristics as obtained in the seventh embodiment.

DESCRIPTION OF SYMBOLS 1 Illumination part 2 Package board 3 Light source 4 Lens part 4a Incident surface 4b, 11a, 11b, 11c, 12a, 12b, 12c, 13a, 13b, 13c Ejection surface 10 Illumination device

Claims (5)

A light source; and a lens unit that covers the light source and refracts light from the light source in a predetermined direction.
The lens part is
An incident surface located on the light source side, at least a part of which is formed as a spherical surface with a spherical center located at the center of the light source;
An exit which is located on the opposite side of the light source across the incident surface, and at least a part of which is a convex surface formed as at least one conic surface centered at a position different from the spherical center position of the incident surface. and the surface, the possess,
Each of the conic surfaces of the exit surface has the center position of the light source as an origin, is horizontal with respect to the mounting surface of the light source, and includes the center of the exit surface and the center of the entrance surface The direction parallel to the surface perpendicular to the placement surface is the X direction, the normal direction to the placement surface is the Z direction, and the position coordinates of the sphere center of the incident surface are A (Xa, Za). And D (Xd, Zd) is the position coordinate of the intersection of a line perpendicular to the tangent line with the arbitrary position coordinate C (Xc, Zc) on the exit surface as a contact point and an arbitrary straight line passing through the position coordinate A. The position coordinate of the center of the exit surface is B (Xb, Zb), the major radius of the conic surface is a, the minor radius is b, and the angle between the straight line passing through the center of the exit surface and the X axis is θ When the refractive index of the medium of the lens unit is n, the following formula

A lighting device configured to satisfy the requirements. A light source; and a lens unit that covers the light source and refracts light from the light source in a predetermined direction.
The lens part is
An incident surface located on the light source side, at least a part of which is formed as a spherical surface with a spherical center located at the center of the light source;
An exit surface located on the opposite side of the light source across the entrance surface, at least a portion of which is formed as at least one conic surface centered on a position different from the spherical center of the entrance surface; I have a,
When the shape of the exit surface is a spherical surface, the center position of the light source is the origin, the direction is horizontal to the mounting surface of the light source, and the center of the exit surface and the center of the entrance surface The direction parallel to the plane perpendicular to the mounting surface of the light source including X direction is the X direction, the normal direction to the mounting surface is the Z direction, and the position coordinates of the spherical center of the incident surface are A ( Xa, Za), where the position coordinate of the spherical surface of the spherical surface of the exit surface is B (Xb, Zb), the radius of the spherical surface of the exit surface is rb, and the refractive index of the medium of the lens unit is n And the following formula

A lighting device configured to satisfy the requirements. The lighting device according to claim 1 or 2 , wherein a center of each conic surface of the exit surface is located in a space of a sphere that partially forms a spherical surface of the entrance surface. The illuminating device according to any one of claims 1 to 3, wherein the emission surface includes two or more conic surfaces and a semi-conical truncated cone or a semi-cylinder that connects the two or more conic surfaces. The lighting device according to claim 1, wherein the lighting unit includes a plurality of the lighting units, and the lighting units are arranged at equal intervals.

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