JP2009198524A - Solar lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a columnar solar lens made of a transparent material and capable of condensing the sunlight reaching the whole surface of the solar lens from all the directions and all the altitudes on a bottom face of the lens. <P>SOLUTION: This solar lens is constituted by engaging a condensing lens having inverted trapezoidal cross section with the columnar vertical condensing lens through a minute cavity, engaging a straightening lens like saw teeth constituted by arranging innumerable straightening units having an isosceles triangle shape with a light emission face through a minute cavity, reflecting the rays entering from the whole surface of the outer periphery of the lens on inclined faces of the vertical condensing lens and the condensing lens and an inclined face of the straightening lens or transmitting the rays through these inclined faces, and condensing the rays on the light emission face. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a solar lens configured to collect sunlight rays from all directions corresponding to the entire surface of a solar lens formed in a columnar shape on a light exit surface.

As a method for concentrating sunlight, a convex lens, a modified Fresnel lens, a concave mirror, or the like is generally used. However, these lenses and reflectors that collect light rays on the optical axis collect sunlight moving through the lens. In order to shine, it was necessary to constantly adjust the direction of the light receiving surface according to the position of the sun. For this reason, a method of condensing light by combining light refraction and total reflection has been proposed as a method of condensing light regardless of the azimuth or altitude of the sun.
Japanese Patent Application No. 2008-025808 Solar Lens Japanese Patent Application No. 2008-029821 Solar Lens

  However, since the proposed method is a method of condensing only the sunlight rays that enter the upper surface of the inverted trapezoidal condenser lens, a solar lens with a large light incident area is required to use a larger amount of sunlight. did. The present invention solves this drawback.

  The present invention solves the previous problem by not only collecting the sunlight rays that hit the upper surface of the solar lens but also collecting the sunlight rays that hit the side surface of the solar lens.

  Sunlight from all directions hitting the solar lens can be condensed on the light exit surface on the lower surface of the lens, so that it is possible to reduce the quantitative fluctuation of the condensing energy due to fluctuations in solar altitude compared to a flat solar lens and to stack in a tower shape In this way, the light can be condensed with a large projected area.

  In the following description, a light beam that is refracted and incident according to the refractive index of the material from the light incident surface of the condenser lens and the outer surface of the vertical condenser lens is incident, and the light beam that is reflected by the condenser slope 7 of the condenser lens. Is referred to as reflected light. Further, among the sunlight rays having an altitude of 0 to 90 degrees, a light beam having the lowest altitude that is a target of light collection is referred to as a minimum incident angle light beam. In addition, in order to distinguish from the solar lens of the said patent document, the solar lens of the said patent document 1 and the patent document 2 is called a planar solar lens.

  FIG. 1 is a plan view of a square solar lens 1 made of a homogeneous transparent material having a high light transmittance such as glass or synthetic resin. The light incident surface 2 for sunlight and the light exit surface 3 from which the condensed light rays are emitted are shown. The relationship between the light incident surface 2 and the light exit surface 3 is the same. Reference numeral 5 denotes a rectifying lens that rectifies light rays incident on the condenser lens. Since it is not a lens for image formation, the planar shape may be circular or rectangular.

  FIG. 2 is a cross-sectional view, and the solar lens 1 is formed by engaging a columnar vertical condenser lens 13 with a condenser lens 4 having an inverted trapezoidal cross section and optically separating them from each other by a minute gap (not shown). Has been. Further, the condensing lens is an inverted triangular hollow 12, and this hollow slope forms a sunlight incident surface 2. Further, a sawtooth rectifying lens 5 in which an infinite number of isosceles rectifying units 10 are lined up is formed on the light exit surface 3 of the condenser lens 4 so as to be engaged with each other through a minute gap.

  The vertical condensing lens 13 is a column having the same size as the outer diameter of the condensing lens 4, and the minimum inclination angle θ of the condensing slope 7 meshing with the condensing lens is incident from the outer surface 14 and reflected by the condensing slope 7. The angle difference α between the reflected ray of the incident angle ray and the line perpendicular to the outer surface 14 is set so as to be equal to or larger than the critical refraction angle of the constituent material, and the sunlight rays entering from the outer surface are reflected from the outer surface 14 and the condensing slope 7. The light is condensed on the light exit surface 3 by repeatedly reflecting between them.

  The inclination angle of the rectifying slope 8 is basically set to the same angle as the inclination angle θ of the condensing slope 7, and the incident light beam is totally reflected or transmitted by the condensing slope 7, the light incident surface 2 and the rectifying slope 8. Then, the light is condensed on the light exit surface 3. The total reflection at the boundary surface with the air gap may be used for the reflection of the light beam at the converging slope 7, but it is compulsory by the mirror surface formed by vapor-depositing a highly reflective metal thin film (not shown). A method of reflecting the light on the surface may be used. Moreover, the method of sticking the reflective mirror of the same slope instead of a metal thin film may be used.

  Further, by fitting a sawtooth auxiliary lens 6 in which countless auxiliary units 11 similar to the rectifying unit 10 are arranged on the light output surface side of the rectifying lens 5 through a minute gap, The emission angle of emitted light is rectified and emitted into the same range of rays as the angle (altitude) of the sunlight that shines.

  In FIG. 2, the converging slope 7 is formed as a single-angle slope, and the outer surface 14 and the light exit surface 3 are formed as flat surfaces. However, in order to finely adjust the condensing performance, it is curved into a gentle convex surface or concave surface. A method of making it possible is conceivable. Similarly, the rectifying slope 8 and the auxiliary slope 9 may be similar slopes with the same single angle as the condensing slope 7, but the traveling angle of the light beam is made fine by giving a slight angle difference or by locally curving. Can be adjusted. For example, the reflection angle and the refraction angle of the light beam can be finely adjusted by changing the angle of the rectifying slope 8 and the auxiliary slope 9 in contact therewith to partially increase or decrease the width of the gap.

  Referring to FIG. 2, the light ray path p1 incident from the upper surface is refracted according to the refractive index on the light incident surface 2 and travels as an incident light beam, and reaches the light incident surface 2 as a reflected light beam on the converging slope 7. Then, after reaching the condensing slope 7 again by total reflection, it reaches the rectifying lens 5. The light beam p2 incident from the outer surface 14 of the vertical condenser lens 13 becomes a reflected light beam on the condensing slope 7 and is totally reflected by the outer surface 14 and reaches the light exit surface 3 on the bottom surface of the vertical condenser lens 13.

  3a to 3e are ray path diagrams when a transparent material having a refractive index of 1.7 is used. The ray path until the sunlight reaches the light exit surface 3 is shown by dividing the ray angle into nine stages for the ray located from the point a1 to the point e1. FIG. 4 shows the path of the light beam traced after reaching the boundary between the condenser lens 4 and the rectifying lens 5 with the light beam angle divided into seven stages for the light beam located from the point a2 to the point e2. is there. The traveling direction of the light beam is drawn almost according to the actual situation. The ray paths of the light rays located at these intermediate points and the ray paths at intermediate angles other than the respective stages can be considered to conform to the exemplified ray paths. In the route diagram, only the light rays incident from the left direction are shown, but the light rays from the right direction proceed in the same way along a route in which left and right are reversed.

  In FIG. 3, the inclination angle of the reflected light incident from the light incident surface 2 and reflected by the converging slope 7 increases from point a to point e and is downward. Therefore, in order to keep the angle difference α between the reflected light beam and the line perpendicular to the light incident surface to be equal to or greater than the critical refraction angle, the light beam incident from the point a is totally reflected by the light incident surface 2. The surface 2 may be formed, and as a result, the light incident surface becomes a curved surface.

  In addition, the inclination angle θ of the light converging slope 7 needs to be set so that the light incident from the outer surface 14 is reflected by the light converging slope and does not pass through the outer face and be dissipated. For this reason, by setting the angle difference between the reflected ray of the minimum incident angle ray incident from the outer side surface 14 and the line perpendicular to the outer side surface to be equal to or larger than the critical refraction angle, all the incident incident rays of interest are output. Can be condensed. The reflected light beam that reaches the light exit surface 3 of the vertical condenser lens 13 is a light beam having a larger inclination than the angle of the incident light beam, but the rectifying lens 5 provided on the light exit surface 3 is the condensing slope 7 at the lower end of the outer surface 14. Rectifies a part of the reflected light beam having a small inclination angle reaching the light exit surface 3 from the light source.

  FIG. 4 shows a situation where the light beam reaching the rectifying lens 5 is transmitted or totally reflected to reach the auxiliary lens 6, and the light beam reaching the auxiliary lens is totally reflected downward and emitted from the light exit surface 3. ing. The auxiliary lens 6 functions to collect leaked light rays that cannot be rectified by the rectifying lens 5. However, even if the auxiliary lens 6 is used, leakage light is generated in the valley s between the rectifying units 10 forming the rectifying lens 5. After entering the auxiliary unit like the light ray q3 and the light rays q4 and q5 in FIG. 4, the light rays that reach the light exit surface without hitting the slope on the opposite side are totally reflected on the light exit surface to become upward rays, and are broken lines. It becomes a loss beam in the path | route of the light ray q6 shown by (5), and the light rays q7 and q8.

  In order to reduce this loss, it is effective to make the auxiliary unit 11 relatively smaller than the rectifying unit 10. By making the auxiliary unit as small as possible, it is possible to keep the leakage light only in the valley s between the rectifying units. If the surface reflection loss when passing through the slope of each lens, the reflection loss of the specular reflector, and the light transmission loss peculiar to the material are ignored, a light collection efficiency close to 100% can be expected.

  The thickness of the condensing lens is such that the reflected light from the converging slope does not pass through the condensing slope on the opposite side and is lost as shown in FIGS. 3c and 3d. It is necessary to set the thickness within a range that does not reach.

  The condensing lens 4 has a function of condensing the sunlight incident from the light incident surface in a narrower range, and the rectifying lens 5 transmits the light beam traveling at an inclination angle greater than the critical refraction angle with respect to the light exit surface 3. The auxiliary lens 6 functions to rectify leaked light rays that cannot be processed by the rectifying lens, and the vertical condenser lens 13 converts sunlight incident from the side face downward to collect light. You can think of something that makes light.

  In the solar lens of the present invention, since the area ratio between the light incident surface 2 and the light exit surface 3 is 1, the light condensing magnification with respect to the incident light from the light incident surface 2 is 1, but the light incident on the vertical condensing lens. Since it can also condense, it is possible to increase the condensing magnification with the laminated solar lens. In addition, by combining a planar solar lens with the lowermost layer of the stacked solar lenses, the light collection magnification can be dramatically increased.

  In addition, since the light ray emitted from the light exit surface becomes a light ray spreading in four directions like a point light source, it is considered that the direction of the light ray emitted by a convex lens or the like can be narrowed down. As a result, when stacking solar lenses, the processing range of incident light can be set narrow in the next-stage solar lens, so there is a possibility that the condensing magnification of the next-stage solar lens can be further increased by arranging a convex lens on the light exit surface. is there.

It is a top view of a solar lens. It is a sectional side view of a solar lens. It is an advancing path | route figure of a solar lens. It is an advancing path | route figure of a rectification lens.

Explanation of symbols

1, solar lens 2, light incident surface 3, light exit surface 4, condenser lens 5, rectifying lens 6, auxiliary lens 7, condensing slope 8, rectifying slope 9, auxiliary slope 10, rectifying unit 11, auxiliary unit 12, collecting light Optical lens hollow 13, longitudinal condenser lens 14, outer surface

Claims (2)

  A columnar vertical condensing lens is meshed with an inverted trapezoidal condensing lens through a small gap, and the angle difference α between the reflected light of the minimum incident angle from the outer surface and the line perpendicular to the outer surface is obtained. The inclination angle θ of the converging slope is set so that it is equal to or greater than the critical refraction angle of the constituent material, and the angle difference β between the reflected light of the incident light from the light incident surface and a line perpendicular to the light incident surface is configured The angle of incidence of the light entrance surface is set so that it is equal to or greater than the critical refraction angle, and the thickness of the condenser lens is set so that the reflected light from the condenser slope does not reach the condenser slope on the opposite side of the condenser lens. Then, the solar lens characterized by condensing the sunlight ray which injects into the light-incidence surface of a condensing lens, and the outer surface of a vertical condensing lens on a light emission surface.   2. The solar lens according to claim 1, wherein a sawtooth rectification lens in which an infinite number of isosceles rectification units inclined at substantially the same angle as the inclination angle θ of the condensing slope is arranged on the light exit surface through a minute gap. A solar lens characterized in that it is configured so that incident light is totally reflected or transmitted by the slope of the rectifying lens and condensed on the light exit surface.

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