JPH0682630A - Optical distributing structure - Google Patents

Abstract

PURPOSE:To distribute proper quantities of light to various lighting fixtures with a lightweight constituent member by improving the optical distributing structure. CONSTITUTION:A light source 5 is installed at the 1st focus f1 of a rotary elliptic surface mirror 8. Light which is emitted by the light source 5 and then reflected by the rotary elliptic surface mirror 8 is converged on the 2nd focus f2, and diffused after crossing it. Plural light guides 11a-11c are arranged to diffused luminous flux (arrows i1-i6) and a curved surface is provided at the light-incidence side end surfaces of the respective light guides to refract the incident light (arrows i1 and i2) to the axes of the light guides as shown by arrows k1 and k2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for distributing light emitted from a single light source to a plurality of light guides and guiding the light to a lamp by each of the plurality of light guides.

[0002]

2. Description of the Related Art As a technique for distributing a light beam emitted from a single light source to a large number of light guides and guiding it to a lamp, Japanese Patent Application Laid-Open No. HEI-2 is proposed.
A centralized illumination system using a high-brightness light source described in Japanese Patent Publication No. 172102 is known. FIG. 2 shows the above known example.
The special bulb 1 shown in FIG. 1A is made of hard glass, and the discharge light emitting mechanism is enclosed in the special bulb 1 and is fed by the lead wires 1a and 1b. There are many (5 in this example) in this special bulb 1.
Light guides 1c to 1g are formed, and the light generated by the discharge is distributed and led out by these light guides. As shown in FIG. 1B, a large number of light guides 1
The light derived from c to 1 g is the optical fiber 2c.
.About.2g lead to the lamps 3c to 3g, respectively (the lamps 3d and 3e are not shown in the figure). In the above-mentioned known example, the special tube 1 is required, and this member is not versatile, which is inconvenient for practical use. To eliminate these inconveniences,
A configuration of FIG. 3 has also been proposed in which a commercially available light source bulb can be used. The light source 5 is installed at the focus F of the rotary parabolic mirror 4 shown in FIG. This light source 5
For example, a commercially available mercury discharge lamp can be used, and it can be attached / detached and replaced. Light incident on the paraboloidal mirror 4 from the light source 5 is reflected parallel to the optical axis Z as indicated by arrows a, b, and c. A large number of optical fibers 6 are installed so as to face the parallel light flux, and each of the light fluxes is made incident and guided to a desired position (lamp not shown) 7 is a glass rod for absorbing heat rays. In the conventional technique shown in FIG. 3, the parallel light flux reflected by the rotating parabolic mirror 4 has a uniform light flux distribution density. Therefore, a large number of optical fibers 6 are evenly distributed in the amount of light. Depending on the application of this light distribution mechanism, the above-mentioned uniform distribution function may be convenient, but it is not suitable for unifying the light source of a vehicle lamp, for example. Generally, a vehicle is equipped with a large number of lamps, a headlight and a stop lamp require a relatively large amount of light, and a tail lamp and a small lamp require a small amount of light. Therefore, if the conventional example of FIG. 3 is applied to the vehicular lamp and the light emission of the light source 5 is evenly distributed, the headlamps and the stop lamps will lack the light quantity supplied, and the tail lamps and the small lamps will supply the light quantity. Is too large, there is a problem that the light must be dimmed by the optical filter. A light distribution structure shown in FIG. 4 is conceivable as a light distribution structure capable of intentionally distributing the light quantity to a large number of light guides by solving the above-mentioned problems. This structure is an unknown one created by the present inventors, and will be referred to as a tentative plan hereinafter. FIG. 4 (A) is a side view, and FIG. 4 (B) is its BB arrow view. 8 is a spheroidal mirror, f ₁ is its first focal point, f ₂ is also its second focal point, and Z is also its optical axis. The light source 5 is arranged near the first focal point. In this proposal, the light source was composed of a mercury discharge tube.

The spheroidal mirror 8 is emitted from the light source 5 described above.
The light flux reflected at is focused on the second focal point f ₂ as shown by arrows d and e, intersects, and then diffuses. A convex lens 9 is provided at a position for receiving the diffused light, and the light is condensed to form a parallel light flux as indicated by arrows d'and e '. A convex lens having such a function is widely used as an aspherical convex lens for a projector-type headlight, for example. Since FIG. 4A is vertically symmetrical with respect to the optical axis Z, the arrow mark is attached to only one side. A large number of light guides 6 are arranged so as to face the parallel light beams d'and e '. The BB arrow view is as shown in FIG. The distribution density of the parallel light flux is dense in the central portion and sparse in the peripheral portion. Using this, for example, a light guide that guides light to a high-luminance lamp such as a headlight or a stop lamp is arranged at the center as shown in 6a of FIG. The light guide for guiding the light to the lamp is arranged at the peripheral portion as shown in 6b of FIG. Accordingly, it is possible to distribute light to each of the lamps without excess or deficiency. Also, FIG.
In the prior art shown in (1), when the number of optical fibers 6 to be arranged is increased, the rotary parabolic mirror 4 is replaced with one having a large diameter to increase the diameter of the parallel light flux (arrows a, b, c). Although it had to be done, in the trial shown in FIG. 4A, the convex lens 9 is replaced with a large diameter lens without moving the spheroidal mirror 8 and the large diameter lens is moved forward of the lamp. Since the diameter of the parallel light flux (arrows d ', e) increases, the number of light guides 6 arranged can be increased.

[0004]

The light distributing device according to the trial shown in FIG. 4 has an excellent effect that the number of the light guides 6 arranged can be easily changed, but the convex lens 9 has a relatively large weight. In addition, the convex lens 9 absorbs light and loses light due to surface reflection. The present invention has been made in view of the above circumstances, and improves it without impairing the "degree of freedom of light quantity distribution", which is an advantage of the light distribution device according to the above-mentioned tentative proposal, and reduces the light loss due to the convex lens. It is an object of the present invention to provide a light distribution device capable of preventing the above and reducing the weight corresponding to the convex lens.

[0005]

If the convex lens 9 is removed from the light distribution structure of the trial shown in FIG. 4 (A) and the light receiving surface of the light guide 6 is arranged along the convex curved surface of the convex lens 9, It becomes like FIG. However, merely the number of the light receiving surface of the light guide 6 just arranged as shown in FIG. 5, the arrows i _1, i ₂ through i arrow j ₁ the light diffused as described _6,
The light cannot be guided in the axial direction of each light guide 6 like j _{2 to} j ₃ . Therefore, the present invention provides each light guide 1 as shown in FIG. 1 corresponding to the first embodiment.
1a, 11b, to form a concave-shaped concave surface on the light receiving surface of 11c, and by forming a transparent thin film 11 having a refractive index higher than the light guide to the concave surface of the light guide, an arrow i _1, i _The diffused light fluxes such as _{2 to} i ₃ are applied to the thin film 1 having the concave curved surface.
Refraction at 1 and let it enter parallel to the axis of the light guide as indicated by arrows k ₁ , k ₂ and k ₃ .

[0006]

According to the above structure (see FIG. 1), the diffused light fluxes (arrows i ₁ , i _{2 to} i ₃ ) reflected by the spheroidal mirror 8 and intersecting at the second focal point f ₂ are light guides 11a to 11c. in concave surface formed on the light receiving surface of, it is allowed refracted as indicated by the arrow _{k 1, k 2, k 3} , incident parallel to the light guide axis, is effectively guided.

[0007]

FIG. 1 is a schematic view showing an embodiment of a light distribution structure according to the present invention, in which a light source 5 and a spheroid having the same drawing reference numbers as those in the trial shown in FIG. 4 (A) are attached. The face mirror 8 is a component similar to or similar to that in the above-mentioned trial. Each light guide 11a~11b the above side facing the second focus f ₂ of the rotary ellipsoidal mirror 8 (i.e. the end face of the light entrance side) is formed in a concave shape of the concave surface. Then, a transparent thin film 11 having a higher refractive index than the light guide is formed on the concave curved surface of each light guide. As a result, for example, with respect to the light guide 11a, the arrow i ₁ ,
The light flux that has entered as i ₂ is refracted by the thin film, becomes parallel to the axis of the light guide 11a as shown by arrows k ₁ and k ₂ , and advances in the light guide 11a. In this way, the light flux is guided to each of the plurality of light guides in parallel with the axis thereof, so that the light is not attenuated in the light guides and the light is distributed and guided with high efficiency.

As is clear from a comparison between the embodiment of FIG. 1 and the tentative plan of FIG. 4 (A), since the convex lens 9 is not provided in this embodiment, the number of components is small, the weight is light, and the convex lens is It is clear that it does not suffer the loss of light due to. The reason why the convex lens can be omitted in the present embodiment (FIG. 1) is that a concave curved surface is provided on the light-incident side end surface of the light guide, and a thin film 11 is formed to refract incident light, thereby making the light guide axial direction. Because I chose Next, it will be described that the distribution of the light amount can be arbitrarily set in the present embodiment. The light flux (arrows i _{1 to} i ₆ ) that has passed through the second focus f ₂ of the spheroidal mirror 8 is a diffused light flux. In this example, since the end faces of the respective light guides on the light incident side are aligned with the plane DD, the diameter dimension of the light guide disposable area is θ shown in the figure. When moved to -E, a large number of light guides can be arranged in the area having the diameter dimension φ. Further, if the light guides are aligned with the surface GG, the number of light guides installed is reduced, but the amount of light received by one light guide can be increased. In this way, there is a large degree of freedom in which the number of light guides to be installed can be arbitrarily set in terms of design. FIG. 6 shows a thin film 1 provided on the surface of the light guide 6.
1 is an optical path diagram around 1. The light incident on the point P is the thin film 11
Since the refractive index n ₂ is larger than the refractive index n _{1 of the} atmosphere, it advances to the point Q in the thin film at an angle θ ₂ (θ ₂ <θ ₁ ) with the normal line l ₁ ′ of the tangent line l ₁ of the point P. This point Q is on the boundary between the thin film and the optical fiber, and since the refractive index n _{2 of the} thin film is larger than the refractive index n _{3 of} the light guide (specifically, the core of the optical fiber), the normal to the tangent line l ₂ of the point Q. l ₂ 'light incident at angle theta ₃ formed between the, l _2' proceeds in square form and _{θ 4 (θ 4> θ 3} ). Therefore, the light incident on the light guide is substantially parallel to the center line. Since the optical paths of light incident on points other than the point P undergo refraction in substantially the same manner, all incident light is substantially parallel to the center line of the light guide.

[0009]

As described above, when the light distribution structure of the present invention is applied, a light beam emitted from a single light source can be distributed by a lightweight constituent member, and the degree of freedom of light quantity distribution is high. Has excellent practical effects.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a light distribution structure according to the present invention, in which optical paths are shown in a schematic side view.

FIG. 2 is a perspective view showing a known example of a light distribution structure.

FIG. 3 is a schematic side view showing a known example different from the above.

4A and 4B show a tentative plan relating to a light distribution device, FIG. 4A is a schematic side view, and FIG. 4B is a BB cross-sectional view thereof.

FIG. 5 is an explanatory diagram of an improvement plan of the trial plan.

FIG. 6 is an optical path diagram in the vicinity of the thin film 11 of the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Special tube, 2 ... Optical fiber, 3 ... Lamp, 4 ... Rotating parabolic mirror, 5 ... Light source, 6 ... Optical fiber, 7 ... Glass rod, 8 ... Spheroidal mirror, 9 ... Convex lens, 11a-11.
c ... Light guide.

Claims (1)

[Claims] 1. A spheroidal mirror, a light source disposed near a first focal point of the spheroidal mirror, and a light beam emitted from the light source and reflected by the spheroidal mirror is converged at a second focal point. After that, a plurality of light guides are arranged substantially parallel to the optical axis of the spheroidal mirror at the place where the light is diffused, and the end surface of the light guide on the light incident side is formed into a concave lens surface curved surface. Further, a light-transmissive thin film having a refractive index higher than that of the light guide is formed on the curved surface, and the diffused light is refracted parallel to the center line of the light guide and is incident. A light distribution structure characterized by the above.