JPS60232501A - Condenser lens - Google Patents

Abstract

PURPOSE:To converge light from various directions to a specific direction by connecting arcuately plural linear Fresnel lens units which are so curved as to converge light in the lengthwise direction of a lens so that light is converged in their lens aperture directions. CONSTITUTION:Linear Fresnel lens units 2 which are formed arcuately in the direction of lens length (b) are connected successively and arcuately at right angles to the direction of the lens length (b), i.e. in the direction in the lens aperture (a) to form the condenser lens 1. In this case, the linear Fresnel lens units 2 are connected arcuately to a radius of curvature equal to focal length F and in the direction of the tangent to an arc with the radius of curvature equal to the focal length. Light transmitted at right angles to the surface of each linear Fresnel lens unit 2 from each position in the direction of the lens length (b) of the condenser lens 2 is converged on a focus P and light transmitted at right angles to the surface of each linear Fresnel lens 2 from each position in the direction of the lens aperture (a) is also converged on the focus P.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a condensing lens that condenses light toward the center.

(Prior art) Generally, a convex lens is known as a condensing lens.
It has the disadvantage that the center thickness becomes large and it becomes extremely heavy, so it lacks versatility. Therefore, there is a flat Fresnel lens that has a similar light-concentrating effect, is lightweight and is not bulky, and is used for various purposes such as lighting. Fresnel lenses include circular Fresnel lenses that condense light at the center and linear Fresnel lenses that condense light into a line.

(Problems to be Solved by the Invention) However, when condensing light using the circular Fresnel lens, the optical axis of the circular Fresnel lens must be aligned with the direction of the light.

Therefore, a daylighting device has been invented that focuses sunlight with a circular Fresnel lens and uses the light guiding properties of optical fiber to illuminate the dark room of a residence, but a device that tracks the sun's orbit is required. However, the cost of the entire daylighting device is extremely low, and it has the disadvantage of poor maintenance.

(Means for Solving the Problem) Therefore, the present invention provides a condensing lens that condenses light from various directions in a predetermined direction. A plurality of linear Fresnel lens units, which are curved so as to condense light toward each other, are arranged in a circular arc shape so as to mutually condense light in the direction of the lens aperture.

(Function) According to the present invention, light transmitted perpendicularly from each surface in the lens length direction of each linear Fresnel lens unit is focused toward the center, and each surface of each linear Fresnel lens unit in the lens aperture direction is focused toward the center. Similarly, the light that is transmitted more vertically is focused toward the center.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. FIG. 1 shows a condenser lens l according to the present invention, and FIG. 2 is a partial sectional view thereof.

Fig. 3 shows a linear Fresnel lens 2 having a predetermined lens diameter a, lens length b, and focal length F, and an uneven prism groove 3 for focusing light is formed on the - side in the lens length b direction. has been done. The light transmitted from the direction perpendicular to the surface of the linear Fresnel lens 2 is condensed linearly at the focal point P position. The condensing lens 1 has a third lens such that the light condensed by the linear Fresnel lens 2 is condensed at the center in the lens length b direction.
As shown by the imaginary line in the figure, the linear Fresnel lens 2 is formed in an arc shape with respect to the lens length b direction, and a plurality of units of the linear Fresnel lens 2 curved into the arc shape are shown in FIG. As shown, the lenses are integrally connected in the radial direction a, and
The lenses are arranged in an arc shape at a predetermined angle θ so that the light collected by each linear Fresnel lens 2 is focused at the center. Therefore, the condenser lens 1 has a lens length b
It has a so-called dome-like structure in which a plurality of two units of linear Fresnel lenses each formed in an arc shape in the direction are arranged in a circular arc shape in a direction orthogonal to the lens length b direction, that is, in the lens diameter direction a. There is.

In FIG. 1, each linear Fresnel lens 2 unit is formed in an arc shape with a radius of curvature of focal length F in the lens length b direction, and the focal length The structure is such that they are connected in the tangential direction of a circular arc having a radius of curvature of F.

The embodiment of the present invention is constructed as described above, and the light transmitted perpendicularly to each surface of each linear Fresnel lens 2 unit from each position in the lens length b direction of the condensing lens l is condensed at a focal point P. On the other hand, light transmitted perpendicularly to each surface of each linear Fresnel lens 2 unit from each position in the direction of the lens diameter a of the condensing lens 1 is also condensed at the focal point P. That is, if there is light that reaches the spherical outer peripheral surface of the condenser lens 1 perpendicularly, that light will always be condensed at the focal point P, and as in the past, the optical axis of the Fresnel lens will be aligned in the direction of the light. There is no need to align the light with the optical axis, and the light that matches the optical axis is focused in a predetermined direction. When manufacturing the condensing lens 1, it can be easily manufactured by press-molding a plate material with good light transmittance, such as acrylic resin, styrene resin, polycarbonate, glass, etc., using a mold. In addition, when molding from a thermoplastic resin plate, the plate material can be heated and roll-molded using a hot roll with prism grooves 3 carved therein, and then pressed into a mold having a predetermined curvature to easily form the sheet.

Furthermore, the prism groove 3 can also be cut with a knife or the like. From the above, the condenser lens l can be provided at low cost with high productivity.

Although the prism groove 3 is shown provided on the inner surface of the condenser lens 2, it may be provided on the outer surface.

4 to 10 show the above-mentioned condensing lens 1 as a daylighting device adapted to houses with various types of roofs. 6 is provided.

That is, an opening serving as a top light is provided in the ridge 5, and lens supports 7 are erected on both sides of the opening, and a condensing lens 1 is mounted and supported across the upper part of the opening. Further, in FIG. 4, 8 is a transparent plate for lighting, and 9 is a louver.

As shown in FIG. 5, one end surface of the optical fiber assembly 10 made of acrylic fibers or the like is placed at the condensing part of the condensing lens 1, that is, at the focal point P. The other end is appropriately divided, and each end 11 of each divided optical fiber assembly 10 is guided to each guide as appropriate. Therefore, the sunlight focused by the condensing lens 1 reaches one end surface of the optical fiber assembly 10, passes through each optical fiber material, and is diffused in each room from the end surface of each end portion 11. . In order to improve this diffusion effect, each end 11
A concave lens or the like for diffusion may be provided on the end face. As described above, sunlight can be effectively guided to each room other than the floor directly below the top light. In addition, the whole sky scattered light is
The light passes through the entire surface of the condensing lens l and is guided into the room on the floor directly below as scattered light, just like a normal skylight or light window.

1. The dome-shaped condensing lens 1 has a central angle θ in the lens length b direction of approximately 180 degrees, and a central angle θ2 in the lens diameter direction a of approximately 30 degrees, so that it is configured into a band-shaped spherical surface. If they are installed at appropriate angles, with the lens radial direction a set as the east-west direction and the direction of the lens diameter a as the north-south direction, the condensing lens l will always be oriented toward the solar orbital plane, and from sunrise to sunset, the lens will be focused on wealth. It can concentrate light continuously, prevent pulsations in the amount of daylight due to changes in solar altitude, and can always respond to seasonal changes in solar altitude. Therefore, there is no need for a device that tracks the sun's orbit as in the past, and its construction and maintenance are as easy as conventional skylights and light fixtures, making it possible to provide inexpensive daylighting equipment and improve maintainability. Figures 6 and 7 are roof surface 1 facing south.
A lighting device 6 is provided in a part of two dormers, and 13 is a transparent plate such as glass for lighting. 8 to 10 show a hipped roof 4 with a lighting device 6 provided on the ridge 5-side.

Note that the lens length b direction of the condensing lens 1 is the east-west direction,
Lighting device 6 installed with the Renthro diameter a direction as the north-south direction
However, the lens length b direction may be set as the north-south direction, and the lens diameter direction a may be set as the east-west direction. In addition, when installing the roof surface, it is only necessary to install it according to the shape and ridge direction of each roof so that light can be focused over a wide range in the east-west direction. The central angle θ1 in the direction and the central angle θ2 in the direction of the lens aperture may be appropriately set, and the north-south inclination may be appropriately adjusted for installation.

Further, although the condensing lens 1 is shown as being used in a daylight device 6, it can also be used in various devices that collect and utilize human sunlight, such as for collecting heat in solar water heaters.

(Effects of the Invention) According to the present invention, with respect to the outer peripheral surface configured in a substantially spherical shape,
Since the light transmitted perpendicularly from various directions is focused in a predetermined direction, there is no need to adjust the direction of the condenser lens depending on the direction of the light. It also has the advantage of being easy to manufacture, having good productivity, and being available at low cost.

[Brief Description of the Drawings] Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a sectional view taken along line nn in Fig. 1, Fig. 3 is a perspective view of a linear Fresnel lens, Fig. 4 is a perspective view showing one example of a daylighting device equipped with the present invention, FIG. 5 is an explanatory view of the same, and FIGS. 9 is a view taken along the line IV-IV in FIG. 8. 1... Condenser lens, 2... Linear Fresnel lens, a
...Lens aperture, b...Lens length. Patent Applicant Kubota Iron Works Co., Ltd. Procedural Amendment (Voluntary) 1985, Togashi 5th 1, ``IG Notice 1988 Special Request No. 88685 2, Name of invention Condensing lens 3 Person making correction Relationship to the incident: Tokukidenshiman (105) Kubota Iron Works Forestry Company 4, Agent 8577 7. Contents of amendment (1) Submit the clean jar of the drawing as attached [no change in content].

Claims (1)

[Claims] 1. A plurality of linear Fresnel lens units curved so as to condense light in the lens length direction are arranged in a circular arc shape so as to mutually condense light in the lens aperture direction. condensing lens.