JP5147358B2 - Illumination optics - Google Patents

Description

  The present invention relates to an illumination technique, and more particularly to a technique for illuminating an illumination area extending at a predetermined width.

In recent years, high-intensity white LED elements are being provided at low cost, and lighting devices using such LED elements as illumination light sources have been proposed (for example, see Patent Document 1). In this type of illumination device, a light distribution lens such as a Fresnel lens is disposed around an LED element to illuminate a circular or elliptical illumination area.
In addition to the lens formed on the mold resin of the LED element, a reflector or prism is provided around the LED element, and these LED elements are arranged in a matrix to illuminate the illumination area. (See, for example, Patent Document 2).

JP 2005-196983 A JP 2004-253478 A

However, such a conventional technique is intended to illuminate a circular, elliptical, or rectangular illumination area, and therefore has a problem in that an illumination area extending at a predetermined width cannot be efficiently illuminated.
Although this type of white LED element has greatly improved brightness, it has a lower light intensity than conventional illumination light sources such as fluorescent lamps, high-pressure mercury lamps, metal halide lamps, sodium lamps, etc. It is difficult to illuminate with sufficient illuminance. Therefore, it is necessary to efficiently distribute the luminous flux from the LED element to a desired illumination area.

Since the conventional technology has a circular or elliptical illumination area having a two-dimensional expansion, when applied to an illumination area extending at a predetermined width, extra light is emitted in the width direction of the illumination area. Therefore, the illuminance of the desired illumination area is reduced. In the prior art, since light is uniformly emitted to a circular or elliptical illumination area, the illuminance at the peripheral edge of the illumination area decreases. Therefore, particularly in an illumination area that extends with a predetermined width, the illuminance of the far end area is insufficient, so that it is not possible to obtain uniform brightness, that is, good brightness uniformity in the illumination area. .
The present invention is for solving such problems, and it is possible to efficiently illuminate an illumination area extending at a predetermined width with sufficient luminance and good luminance uniformity using a light source composed of LED elements. An object of the present invention is to provide an illumination optical system.

  In order to achieve such an object, the illumination optical system according to the present invention illuminates an illumination area extending at a predetermined width with a diffused light beam from a light source composed of a plurality of LED elements arranged in the longitudinal direction of the illumination area. An illumination optical system that emits a fan-shaped condensed light beam that extends in the longitudinal direction of an illumination area by condensing a diffused light beam from a light source in an angle area corresponding to the width of the illumination area in the width direction of the illumination area The lens and the condensed light beam condensed by the sub lens are emitted toward the illumination area as a whole, and a part thereof is refracted along the longitudinal direction toward the far end area in the illumination area and emitted. And a main lens.

At this time, the main lens has a saddle shape that extends in the width direction and curves along the longitudinal direction, and refracts the incident light of the condensed light flux between the bottom and the end of the curved portion. A lens may be used by forming one or more partial lenses that emit light to the illumination area.
At this time, a convex lens having an optical axis in the direction of the far end region of the illumination region may be used as the partial lens of the main lens.
Further, as a partial lens of the main lens, a concave lens having an optical axis in the direction of the central area of the illumination area may be used.

Further, as a partial lens of the main lens, a convex lens that emits a part of the light emitted toward the intermediate region between the central region of the illumination region and the far end region of the condensed light beam toward the far end region. It may be used.
Further, as the partial lens of the main lens, a convex lens that emits a part of the light emitted toward the far side from the illumination area in the condensed light beam may be used.
Further, as a partial lens of the main lens, a part of the light emitted toward the central region of the illumination region of the condensed light flux is directed toward an intermediate region between the central region and the far end region, or a far end region. A concave lens that emits light may be used.

Further, the main lens has a hook shape that extends in the width direction and curves along the longitudinal direction, and the thickness gradually increases from the bottom of the curved portion toward the intermediate portion between the bottom and the end. You may form so that it may become.
Further, the main lens has a saddle shape that extends in the width direction and curves along the longitudinal direction, and the thickness gradually increases from the end of the curved portion toward the intermediate portion between the end and the bottom. You may form so that it may become thick.

According to the present invention, the diffused light beam emitted downward from the LED element of the light source unit is condensed into a fan-shaped condensed light beam that spreads along the longitudinal direction of the illumination area by the sub lens, and then, by the main lens, In addition to being emitted toward the entire illumination area, a part of the condensed light flux is refracted along the longitudinal direction and emitted toward the far end area in the illumination area.
Accordingly, the diffused light flux from the LED element of the light source unit can be efficiently collected in a desired illumination area extending with a predetermined width, and sufficient illuminance is obtained even in the far end area where the illuminance is insufficient compared to the central area. be able to. For this reason, even when an LED element is used as the light source, it is possible to efficiently illuminate with sufficient road surface luminance and good luminance uniformity over the entire illumination area.

Next, embodiments of the present invention will be described with reference to the drawings.
[Illumination optics]
First, an illumination optical system according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram showing an illumination optical system according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a perspective view of the light source unit as viewed obliquely from below. FIG. 4 is a perspective view of the sub lens as viewed obliquely from below. FIG. 5 is a perspective view of the main lens as viewed obliquely from below.

  The illumination optical system is an optical system that illuminates an illumination area extending at a predetermined width with a diffused light beam from a light source composed of a plurality of LED elements arranged in the longitudinal direction of the illumination area. For example, when illuminating a road such as a roadway or a sidewalk, the illumination optical system is installed at a height of 8 m to 12 m from the road, and is arranged at equal intervals along the road at intervals of 35 m.

  In the present embodiment, by condensing the diffused light beam from the light source unit 1 in an angle region corresponding to the width of the illumination region in the width direction of the illumination region, a fan-shaped condensed light beam extending in the longitudinal direction of the illumination region is emitted. The sub-lens 2 and the condensed light beam collected by the sub-lens 2 as a whole, are emitted toward the illumination area, and a part of the sub-lens 2 is refracted along the longitudinal direction so that the far-end area in the illumination area And a main lens 3 that emits light in the direction.

  Next, the configuration of the illumination optical system will be described in detail. Below, in order to make an understanding easy, it demonstrates as an example the case where it illuminates using the illumination optical system which has arrange | positioned the illumination area | region above it. Further, the longitudinal direction in which the illumination area extends is defined as the longitudinal direction X, and the width direction orthogonal to the longitudinal direction X and transverse to the illumination area is defined as the width direction Y, and orthogonal to the longitudinal direction X and the width direction Y. A direction from the illumination optical system toward the illumination area is defined as a downward direction Z. The surface of the illumination optical system viewed from the opposite side of the illumination area is the front of the illumination optical system.

  As shown in FIG. 3, the light source unit 1 includes a substrate 11 having a rectangular shape in plan view and a light emitting unit 13 in which a plurality of LED elements 14 are mounted in a row on the bottom surface 12 of the substrate 11. Each LED element is composed of a surface-mounted LED chip, and a diffused light beam diffusing in all directions is emitted from the LED element. The center position of the light emitting portion 13 in the longitudinal direction X and the width direction Y is referred to as a light emission center point 15.

  The sub-lens 2 is made of glass or transparent resin as a whole, and as shown in FIG. 4, a lens portion 21 such as a cylindrical lens having a long, downwardly convex shape along the light-emitting portion 13 of the light source unit 1. And a connecting portion 22 that connects the upper end portions of the adjacent lens portions 21 to each other. By the connecting portion 22, the lens portions 21 are arranged in parallel and integrated according to the arrangement pitch of the light emitting portions 13 of the light source unit 1. The center position in the longitudinal direction X and the width direction Y of each lens unit 21 is referred to as an optical center position 23.

  The main lens 3 is made of glass or transparent resin as a whole, and includes a lens portion 31 that extends in the width direction Y and has a hook shape that curves downward as shown in FIG. Further, the lens unit 31 has partial functions 31R, 32R, 32R, having different functions in the depression direction along the longitudinal direction X with respect to the optical center position P between the left and right end portions 3A and the bottom portion 3B of the curved portion. 33R and partial lenses 31L, 32L, and 33L are connected to each other. Among these, the partial lenses 31R and 32R can be regarded as one partial lens (convex lens) 34R, the partial lenses 31L and 32L can be regarded as one partial lens (convex lens) 34L, and the partial lenses 33R and 33L are defined as 1. One partial lens (concave lens) 33 can be considered.

  In this way, a plurality of light emitting units 13 of the light source unit 1 are arranged in parallel in the longitudinal direction in parallel with the longitudinal direction X, and the sub lens 2 has a longitudinal direction at a position below the light emitting units 13. The light emitting units 13 are arranged in parallel. The main lens 3 is disposed below the sub-lenses 2 in parallel with the width direction Y in which the longitudinal direction is perpendicular to the light emitting units 13 and the sub-lenses 2.

  As shown in FIG. 1 and FIG. 2, the lens unit 31 is a left and right center position in the longitudinal direction X of the lens unit 31 as a conjugate point at which a desired illumination area is obtained at the curved inner upper position. An optical center position (optical center line) P is designed at a position slightly above the left and right end portions 3A of the curved portion. The light source unit 1 is arranged so that the light emission center point 15 of the light emitting unit 13 coincides with the light center position P of the main lens 3. Further, the sub lens 2 has the light source unit 1 and the main lens so that the light center position 23 of the lens unit 21 is positioned on the optical axis Q parallel to the downward direction Z passing through the light emission center point 15 and the light center position P. 3 is arranged.

  Thereby, the diffused light beam emitted downward from the LED element 14 of the light source unit 1 is condensed by the sub lens 2 into a fan-shaped condensed light beam that spreads in the longitudinal direction X, and then illuminated by the main lens 3. In addition to being emitted toward the entire region, a part of the condensed light beam is refracted along the longitudinal direction X and emitted toward the far end region in the illumination region.

[Operation of optical system]
Next, the operation of the optical system of the illumination optical system according to the embodiment of the present invention will be described with reference to FIGS.
FIG. 6 is a front view showing an illumination optical system according to an embodiment of the present invention. FIG. 7 is a plan view showing an illumination optical system according to an embodiment of the present invention. FIG. 8 is an explanatory diagram showing the light diffusion characteristics of the main lens. FIG. 9 is an explanatory diagram showing light distribution characteristics of a single light source unit. FIG. 10 is an explanatory diagram showing the light distribution characteristics of the light source unit when the main lens of the illumination optical system according to the embodiment of the present invention is used.

The illumination area 8 is an area where a predetermined luminance is obtained by illumination using the illumination optical system according to the present embodiment, and is substantially rectangular. The diffused light beam from the light emitting unit 13 disposed at the optical center position P of the lens unit 31 is condensed by the sub lens 2 into a fan-shaped condensed light beam that spreads in the longitudinal direction X, and then guided to the lens unit 31. It is burned.
This condensed light flux has an angle spread corresponding to at least the width of the illumination area 8 in the width direction Y. For this reason, when the distance from the illumination optical system to the illumination area 8 is long, as shown in FIG. 2, light beams are substantially parallel in the width direction Y, and the lens unit 31 collects the condensed light flux in the width direction Y. Has little effect on. Therefore, the description of the light distribution function in the width direction Y is omitted here, and the light distribution function of the main lens 3 in the depression direction along the longitudinal direction X will be described.

  In the following, the light distribution characteristics of the main lens 3 relating to the light center position P, that is, the condensed light beam emitted from the left and right centers of the light emitting unit 13 of the light source unit 1 will be described. As shown in FIG. The light emitting portion 13 has a certain length along the longitudinal direction X. Therefore, actually, the illumination area slightly shifted along the longitudinal direction X with respect to the illumination area 8 so as to overlap the illumination area 8 formed by the condensed light beam emitted from the right and left center of the light emitting unit 13. Is formed by the main lens 3 based on the condensed light flux emitted from the left and right end portions of the light emitting unit 13.

  As shown in FIG. 8, the lens portion 31 has three angles provided in the angular direction from the left and right end portions 3A to the bottom portion 3B of the curved portion in the depression direction along the longitudinal direction X with the optical center position P as the center. Corresponding to each of the regions θ1, θ2, and θ3, it is composed of a compound lens in which partial lenses having different functions are connected and formed.

  Hereinafter, the boundary direction between the angle region θ1 and the angle region θ2 is defined as the angle direction θA when viewed from the optical center position P, and the boundary direction between the angle region θ2 and the angle region θ3 is viewed from the optical center position P as the angular direction. θB is defined, and the direction directly below the optical center position P is defined as a direct downward direction θC. These angular regions θ1, θ2, θ3 and angular directions θA, θB are bilaterally symmetric about a line connecting the optical center position P and the direct downward direction θC, that is, the optical axis Q.

The partial lenses 31R and 31L provided in the angular region θ1 starting from the end portion 3A are configured by convex lenses in which the thickness of the curved portion gradually increases from the end portion 3A toward the angular direction θA.
In other words, the partial lenses 31R and 31L refract part of the condensed light beam emitted farther from the far end region 8A of the illumination region 8 along the longitudinal direction X. It is a convex lens that emits toward the region 8A.

Thus, the light 41R and 41L emitted from the sub-lens 2 in the longitudinal direction X in the direction far from the illumination area 8 in the longitudinal direction X, that is, the angle area θ1 in this case, is inclined from the initial traveling direction by the partial lenses 31R and 31L. Refracted downward and emitted as light 51R, 51L to the far end region 8A of the illumination region 8.
Therefore, the irradiance of the far end region 8A, which is relatively insufficient in the illumination region 8, is wasted light emitted in the far direction from the illumination region 8 by the partial lenses 31R and 31L having a relatively simple configuration such as convex lenses. Can be supplemented with a part of. For this reason, even if it is an LED element with little light quantity compared with a lamp | ramp, the illumination area | region 8 can be illuminated efficiently and equally.

The partial lenses 32R and 32L provided in the angle region θ2 starting from the angle region θ1 are configured by convex lenses whose thickness of the curved portion gradually increases from the angle direction θB toward the angle direction θA.
That is, the partial lenses 32R and 32L are configured to cause a part of light emitted toward the intermediate region 8B between the central region 8C of the illumination region 8 and the far end region 8A in the longitudinal direction X of the condensed light flux. It is a convex lens that emits toward the far end region 8A by being refracted along.

Thus, the light 42R and 42L emitted from the sub-lens 2 obliquely downward in the longitudinal direction X in this case to the angle region θ2 is refracted obliquely upward from the initial traveling direction by the partial lenses 32R and 32L. Then, the light 52R and 52L are emitted to the far end region 8A of the illumination region 8.
Therefore, the illuminance of the far end region 8A, which is relatively insufficient in the illumination region 8, is emitted to the intermediate region 8B having sufficient illuminance by the partial lenses 32R and 32L having a relatively simple configuration such as convex lenses. Can be supplemented with part of the light. For this reason, even if it is an LED element with little light quantity compared with a lamp | ramp, the illumination area | region 8 can be illuminated efficiently and equally.

On the other hand, the partial lenses 33R and 33L provided in the angle region θ3 starting from the angle region θ2 are configured by concave lenses in which the thickness of the curved portion gradually decreases from the angle direction θB toward the bottom 3B. Yes.
That is, the partial lenses 33R and 33L refract part of the light emitted toward the central region of the illumination region of the condensed light flux along the longitudinal direction X, thereby causing the intermediate region 8B or the far-end region. It is a concave lens that emits light toward 8A.

As a result, the light 43R and 43L emitted from the sub-lens 2 to the central region 8C in the longitudinal direction X, that is, the angle region θ3 in the longitudinal direction X, is obliquely upward from the initial traveling direction by the partial lenses 33R and 33L. The light is refracted and emitted as light 53R, 53L to the intermediate region 8B of the illumination region 8 and further to the far end region 8A.
Therefore, the partial lenses 33R and 33L having a relatively simple configuration such as concave lenses emit the illuminance of the intermediate region 8B and the far end region 8A, which are relatively insufficient in the illumination region 8, to the central region 8C where the illuminance is excessive. It can be compensated with a part of the light. For this reason, even if it is an LED element with little light quantity compared with a lamp | ramp, the illumination area | region 8 can be illuminated efficiently and equally.

Among the partial lenses, the adjacent partial lenses 31R and 32R and the partial lenses 31L and 32L are convex lenses, and thus can be regarded as an integral partial lens. That is, the partial lenses 31R and 32R may be formed from a convex lens 34R having an optical axis in the direction of the far end region 8A, that is, the angular direction θA.
Thereby, the light 41R emitted in the longitudinal direction X in the direction far from the illumination area 8 in the longitudinal direction X, here the angular area θ1, and the light 42R emitted in the diagonally downward direction, here in the angular area θ2, are the convex lens 34R. Is refracted by the light and emitted as light 51R, 52R to the far end region 8A of the illumination region 8.

Similarly, the partial lenses 31L and 32L may be formed of a convex lens 34L having an optical axis in the direction of the far end region 8A, that is, the angular direction θA.
As a result, 71 L emitted in the longitudinal direction X farther from the illumination area 8 in the longitudinal direction X, here the angle area θ1, and light 42L emitted obliquely in the lower direction, here the angle area θ2, are caused by the convex lens 34L. The light is refracted and emitted to the far end region 8A of the illumination region 8 as light 51L and 52L.

Further, among the partial lenses, the adjacent partial lenses 33R and 33L are both concave lenses, and therefore can be regarded as an integral partial lens. That is, the partial lenses 33R and 33L may be formed from the concave lens 33 having the optical axis in the direction of the central region 8C, that is, the direct downward direction θC on the optical axis Q.
As a result, the light 43R and 43L emitted in the central region 8C direction, here, the angle region θ3 in the condensed light flux is refracted by the concave lens 33, and the light 53R and 53L are the intermediate region 8B and the far-end region of the illumination region 8. It is emitted to 8A.

According to the light distribution characteristic of the main lens 3 shown in FIG. 10, compared to the light distribution characteristic of the light source unit alone in FIG. 9, the direction of the far end region 8 </ b> A of the illumination region 8, here the direct downward direction θC (optical axis Q). ) Shows that high luminous intensity is obtained in the angle direction of about 60 ° in the longitudinal direction X.
The angle direction θA and the angle region θ1 may be determined based on the angular position relationship between the installation height of the illumination optical system and the far end region 8A of the illumination region 8. For the angle direction θB and the angle regions θ2 and θ3, an angle is selected so that the illuminance distribution is within a desired range over the entire illumination region 8, for example, an angle direction of about 40 ° in the longitudinal direction X from the direct downward direction θC. do it.

[Effects of the present embodiment]
As described above, this embodiment collects the diffused light flux from the light source unit in the angle area corresponding to the width of the illumination area with respect to the width direction of the illumination area, so that the fan-shaped condensed light flux spreading in the longitudinal direction of the illumination area is obtained. The exiting sub-lens and the condensed light beam condensed by the sub-lens are emitted toward the illumination region as a whole, and a part thereof is refracted along the longitudinal direction to the direction of the far end region in the illumination region And a main lens that emits light to the screen.

As a result, the diffused light beam emitted downward from the LED element of the light source unit is condensed by the sub lens into a fan-shaped condensed light beam that spreads in the longitudinal direction X, and then directed to the entire illumination area by the main lens. And a part of the condensed light beam is refracted along the longitudinal direction X and is emitted toward the far end region in the illumination region.
Accordingly, the diffused light flux from the LED element of the light source unit can be efficiently collected in a desired illumination area extending with a predetermined width, and sufficient illuminance is obtained even in the far end area where the illuminance is insufficient compared to the central area. be able to. For this reason, even when an LED element is used as the light source, it is possible to efficiently illuminate with sufficient luminance and good luminance uniformity over the entire illumination area.

  Further, in the present embodiment, the main lens has a hook shape that extends in the width direction Y and curves downward along the longitudinal direction X, and the condensed light flux is formed between the bottom portion and the end portion of the curved portion. Since the lens in which one or more partial lenses that refract the incident light and emit to the illumination area is used is used, the fan-shaped condensed light flux that extends along the longitudinal direction X is used in the longitudinal direction X. The desired light distribution characteristic can be easily obtained in the depression direction along the line.

  Further, in the present embodiment, as the partial lens of the main lens, a convex lens that refracts the light irradiated obliquely downward in the condensed light flux and emits it to the far end region of the illumination region is used. A lens having a relatively simple configuration called a convex lens can compensate for a shortage of illuminance in the far end region with a part of light emitted to an intermediate region with sufficient illuminance. For this reason, even if it is an LED element with little light quantity compared with a lamp | ramp, an illumination area | region can be illuminated efficiently and equally.

  In the present embodiment, as a partial lens of the main lens, a convex lens that refracts light emitted farther from the illumination area of the condensed light flux and emits it to the far end area of the illumination area is used. The lens having a relatively simple configuration called a convex lens can compensate for insufficient illuminance in the far end region with a part of wasted light emitted in the far direction from the illumination region. For this reason, even if it is an LED element with little light quantity compared with a lamp | ramp, an illumination area | region can be illuminated efficiently and equally. Moreover, since the light emitted in the far direction is reduced, the glare felt by the driver of the traveling vehicle can be suppressed in the case of road lighting.

  In the present embodiment, a convex lens having an optical axis in the direction of the far end region of the illumination region is used as a partial lens of the main lens. The shortage of illuminance can be compensated by a part of the light emitted to the intermediate region with sufficient illuminance and a part of the wasted light emitted farther from the illumination region. For this reason, even if it is an LED element with little light quantity compared with a lamp | ramp, an illumination area | region can be illuminated efficiently and equally. Moreover, since the light emitted in the far direction is reduced, the glare felt by the driver of the traveling vehicle can be suppressed in the case of road lighting.

  In the present embodiment, as the partial lens of the main lens, the concave lens that diffuses the light irradiated to the central region of the condensed light flux and emits the light to the central region of the illumination region is used. The lens having a relatively simple configuration called a concave lens can compensate for the lack of illuminance in the far end region with a part of the light emitted to the central region where the illuminance is excessive. For this reason, even if it is an LED element with little light quantity compared with a lamp | ramp, an illumination area | region can be illuminated efficiently and equally.

  Further, in the present embodiment, as the partial lens of the main lens, a convex lens that emits part of the light emitted toward the far end from the illumination area of the condensed light flux is used toward the far end area. The lens having a relatively simple configuration called a concave lens can compensate for the lack of illuminance in the far end region with a part of the light emitted to the central region where the illuminance is excessive. For this reason, even if it is an LED element with little light quantity compared with a lamp | ramp, an illumination area | region can be illuminated efficiently and equally.

  Further, in the present embodiment, the main lens has a hook shape that extends in the width direction Y and curves downward, and the thickness gradually increases from the bottom portion toward the middle portion between the bottom portion and the end portion in the curved portion. Since it is formed so as to be thick, the shortage of illuminance in the far end region can be compensated by a part of the light emitted to the intermediate region with sufficient illuminance. For this reason, even if it is an LED element with little light quantity compared with a lamp | ramp, an illumination area | region can be illuminated efficiently and equally.

  Further, in the present embodiment, the main lens has a hook shape that extends in the width direction Y and curves downward, and the thickness gradually increases from the end portion toward the intermediate portion between the end portion and the bottom portion in the curved portion. Therefore, the shortage of illuminance in the far end region can be compensated with a part of useless light emitted in the far direction from the illumination region. For this reason, even if it is an LED element with little light quantity compared with a lamp | ramp, an illumination area | region can be illuminated efficiently and equally.

  Further, in the present embodiment, the main lens has a hook shape that extends in the width direction Y and curves downward, and the thickness gradually increases from the intermediate portion between the end portion and the bottom portion toward the bottom portion in the curved portion. Since it is formed so as to be thin, it is possible to compensate for the shortage of illuminance in the far end region and the shortage of illuminance in the far end region with a part of the light emitted to the central region where the illuminance is excessive. For this reason, even if it is an LED element with little light quantity compared with a lamp | ramp, an illumination area | region can be illuminated efficiently and equally.

  In the present embodiment, a plurality of light source units arranged in parallel in the width direction Y are provided, a sub lens is provided for each light source unit, and individual condensed light beams collected by these sub lenses by the main lens. Is refracted and diffused at an arbitrary depression angle along the longitudinal direction X, so that the main lens can be shared by multiple light source units, reducing product and manufacturing costs, and providing a uniform light distribution in each light source unit The characteristics can be easily realized. When a sufficient amount of light can be obtained with one light source unit, the same effect as described above can be obtained even with a configuration in which only one set of the light source unit and the sub lens is provided for the main lens.

[Extended embodiment]
In the above, the case where the main lens 3 is composed of a plurality of partial lenses 31R, 32R, 33R, 33L, 32L, 31L, or partial lenses 34R, 33, 34L has been described as an example. However, the present invention is not limited to this. For example, a partial lens may be formed only in a specific angle region of the main lens 3.

For example, the partial lenses 31R and 31L may be formed only in the angle region θ1 in FIG. 8, and the curved portions may be formed with the thickness in the left and right angular directions θA for the angle regions θ2 and θ3. As a result, the illuminance of the far end region 8A can be supplemented by using only the action of the partial lenses 31R and 31L.
Further, in FIG. 8, the partial lenses 33R and 33L, that is, the partial lens 33 may be formed only in the angle region θ3, and the curved portions may be formed in the left and right angle directions θB for the angle regions θ1 and θ2. . Thereby, using only the action of the partial lens 33, the illuminance of the intermediate region 8B and further the far end region 8A can be compensated.

  Further, in FIG. 8, the partial lenses 32R and 32L are formed only in the angle region θ2, the curved portion is formed with the thickness in the left and right angle direction θA for the angle region θ1, and the left and right angles are formed for the angle region θ3. The curved portion may be formed with a thickness in the direction θB. As a result, the illuminance of the far end region 8A can be supplemented by using only the action of the partial lenses 32R and 32L.

  Further, any of these partial lenses 31R, 32R, 33R, 33L, 32L, 31L may be formed in any combination. For example, for the angle regions θ1 and θ2, the partial lenses 31R, 32R, 32L, and 31L, that is, the partial lenses 34R and 34L are formed, and for the angle region θ3, a curved portion is formed with a thickness in the left and right angular directions θB. May be. Thereby, it is possible to supplement the illuminance of the far end region 8A by using only the action of the partial lenses 34R and 34L.

  In addition, although the case where these partial lenses are formed symmetrically about the direct downward direction θC has been described, the present invention is not limited to this, and the partial lenses may be formed asymmetrically. In addition, the partial lenses 31R, 32R, and 33R and the partial lenses 31L, 32L, and 33L have been described on the premise that they have light distribution characteristics that are symmetrical with respect to the direct downward direction θC. However, the present invention is not limited to this. Partial lenses having asymmetric light distribution characteristics may be formed.

It is a block diagram which shows the illumination optical system concerning one embodiment of this invention. It is AA sectional drawing of FIG. It is the perspective view which looked at the light source unit from diagonally downward. It is the perspective view which looked at the sub lens from diagonally downward. It is the perspective view which looked at the main lens from diagonally downward. It is AA sectional drawing which shows the principal part of the illumination optical system concerning one embodiment of this invention. It is BB sectional drawing which shows the principal part of the illumination optical system concerning one embodiment of this invention. It is explanatory drawing which shows the light-diffusion characteristic of a main lens. It is explanatory drawing which shows the light distribution characteristic of a light source unit single-piece | unit. It is explanatory drawing which shows the light distribution characteristic of the light source unit at the time of using the main lens of the illumination optical system concerning one embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Light source unit, 11 ... Board | substrate, 12 ... Bottom surface, 13 ... Light emission part, 14 ... LED element, 15 ... Light emission center point, 2 ... Sub lens, 21 ... Lens part, 22 ... Connection part, 23 ... Optical center position, 3 ... Main lens, 31 ... Lens part, 3A ... End, 3B ... Bottom, 31R, 31L, 32R, 32L, 33R, 33L ... Partial lens, 33 ... Partial lens (concave lens), 34R, 34L ... Partial lens (convex lens) ), 41R, 41L, 42R, 42L, 43R, 43L ... light (before refraction), 51R, 51L, 52R, 52L, 53R, 53L ... light (after refraction), 8 ... illumination area, 8A ... far end area, 8B ... intermediate region, 8C ... central region, P ... optical center position, Q ... optical axis, X ... longitudinal direction, Y ... width direction, Z ... downward direction, θ1, θ2, θ3 ... angular region, θA ... angular direction ( Far end region direction), θB ... angular direction (Intermediate region direction), θC... Directly below (center region direction).

Claims (10)

An illumination optical system for illuminating an illumination area extending at a predetermined width with a diffused light beam from a light source composed of an LED element,
A plurality of light source units having a plurality of LED elements arranged in the longitudinal direction of the illumination area, and emitting a diffused light beam from the LED elements toward the illumination area;
It is provided for each light source unit, by condensing the diffused light beam at an angle region corresponding to the illumination region width in the width direction of the illumination area from the light source unit, the condensing light beam sector extending in the longitudinal direction A plurality of sub-lenses that emit light,
Exit the while emitted toward a sub lens to the illumination area as a whole the converging light flux is condensed, its in part is refracted in the direction of the distal end region of the illumination area along the longitudinal direction and a main lens,
An illumination optical system , wherein a plurality of sets of the light source unit and the sub lens are arranged in parallel in the width direction so as to face the main lens . The illumination optical system according to claim 1,
The main lens has a hook shape extending in the width direction and curved along the longitudinal direction, and refracts incident light of the condensed light flux between the bottom and end of the curved portion. One or more partial lenses that exit to the illumination area are formed. The illumination optical system according to claim 2,
The main lens has a convex lens having an optical axis in the direction of the far end region of the illumination region as the partial lens. The illumination optical system according to claim 2,
The illumination optical system according to claim 1, wherein the main lens includes a concave lens having an optical axis in a direction of a central area of the illumination area as the partial lens. The illumination optical system according to claim 2,
The main lens, as the partial lens, is a convex lens that emits a part of the light emitted toward the intermediate region between the central region and the far end region of the illumination region toward the far end region. An illumination optical system comprising: The illumination optical system according to claim 2,
The illumination optical system according to claim 1, wherein the main lens has a convex lens that emits a part of the light emitted toward the far side from the illumination region of the condensed light beam toward the far end region as the partial lens. The illumination optical system according to claim 2,
The main lens, as the partial lens, directs part of the light emitted toward the central region of the illumination region of the condensed light flux toward the intermediate region between the central region and the far end region, or the far end region. An illumination optical system having a concave lens that emits light. The illumination optical system according to claim 1,
The main lens has a saddle shape that extends in the width direction and curves along the longitudinal direction, and the thickness gradually increases from the bottom of the curved portion toward an intermediate portion between the bottom and the end. An illumination optical system characterized by being formed to be thick. The illumination optical system according to claim 1,
The main lens has a saddle shape that extends in the width direction and curves along the longitudinal direction, and the thickness gradually increases from the end of the curved portion toward the intermediate portion between the end and the bottom. An illumination optical system characterized in that the illumination optical system is formed to be thick. The illumination optical system according to claim 1,
The main lens extends in the width direction across a plurality of sub-lenses arranged in parallel in the width direction, and individually collects light fluxes from these sub-lenses and emits them toward the illumination area. An illumination optical system characterized in that a part of each is refracted in the direction of the far end region in the illumination region along the longitudinal direction and emitted.

Images