JPH0629849Y2 - Collector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a light collector, and more particularly to a light collector that efficiently guides a lamp light flux to an optical transmission body.

[Background of the invention]

An illuminator using an optical transmission rod made of a quartz glass rod, an optical glass rod, a silicone resin rod, an acrylic resin rod, etc. has been proposed (Japanese Patent Application No. 60-284).
115, see JP-A-62-142465). In addition, various types of illuminators that utilize the optical transmission properties of fibers have already been proposed.

As a light source of the above-mentioned illuminator, a lamp with a reflecting mirror has been generally used, and light emitted from the lamp with a reflecting mirror is used as an optical transmission rod or a fiber (hereinafter, these are collectively referred to as light. It is incident on the end face of the transmitter. For this reason, in an illuminator using the light transmission body, it has been an important subject to efficiently guide the lamp light flux to the end face of the light transmission body.

[Problems to be solved by the invention]

However, since the lamp filament of the lamp with a reflecting mirror is not a point light source, the beam emitted from the lamp with a reflecting mirror is not focused at a pinpoint, but is focused within a certain area, thus forming a beam waist. It will be. If the converging angle of the reflecting mirror is increased in order to improve the efficiency of condensing on the end face of the optical transmission body, the number of beams that can be condensed increases, but with this, the beam waist tends to thicken. However, the thicker the beam waist, the lower the efficiency for effectively injecting a beam into a light transmission body with a small diameter.
It has been desired to devise a device that achieves both narrowing of the beam waist and increase of the intensity of the emitted beam to improve the light collection efficiency. It is rare. From this point of view, it is conceivable to interpose a condenser lens that condenses the converged light, but if the incident angle of the converged light on the condenser lens surface deviates from the vertical direction, and if it is improper, the condenser lens surface Fresnel reflection will increase the incident loss.

[Means and Actions for Solving Problems]

The present invention has been made in view of the above, and increases the converging beam of the emitted beam of the lamp with a reflector, and
Reduces incident loss due to Fresnel reflection on the condenser lens surface,
Furthermore, the focused beam waist is narrowed down and the output beam is efficiently guided to the end face of the light transmission body with a small diameter on the light incident surface.Therefore, there is a predetermined taper angle that does not interfere with the output beam from the lamp with a reflector. A condenser lens is arranged in the light guide cylinder, and when the output beam of the lamp is incident on the condenser lens surface, the condenser lens is incident with a predetermined directionality on the lens surface. To provide a container.

〔Example〕

Hereinafter, a light collector according to the present invention will be described in detail with reference to the drawings.

1 and 2 show an embodiment according to the present invention, in which a condenser with lens 1 is composed of a light guide tube 2 and a condenser lens 3.

The inner surface of the light guide tube 2 is mirror-finished, and the reflecting mirror 6a
A truncated conical cylinder having a taper angle α that does not interfere with the beam emitted from a lamp 6 with a reflector and a lamp 6c having a filament 6b and a large-diameter opening 4 and a small-diameter opening 5. ing. The reflector 6a of the lamp 6 with a reflector is fitted and locked in the large-diameter opening 4, and the end 8 of the optical transmission body 7 is fitted and locked in the small-diameter opening 5.

A step portion 10 is formed at an intermediate portion of the light guide tube 2, and the condenser lens 3 is locked to the step portion 10.

As shown in the drawing, the condenser lens 3 has a surface 3a facing the end 8 of the light transmission body 7 and a surface 3b facing the lamp 6 with a reflector, which are formed to have different curvatures.
3a of the condenser lens 3 (hereinafter referred to as "second surface")
And 3b (hereinafter referred to as "first surface") are set in relation to the curvature of the reflecting mirror 6a formed of the spheroidal surface.
That is, by arranging the lamp 6c of the lamp 6 with the reflecting mirror at the position of the first focus on the spheroid, the reflected light is condensed at the position of the second focus on the spheroid.
By forming a curved surface of a substantially concentric circle on the first surface centering on the second focus position between the focal points on the ellipse axis, the focused light focused on the second focus position is substantially perpendicular to the first surface. Will be incident on.

On the other hand, the second surface of the condenser lens 3 is formed as a convex lens-like curved surface having a curvature larger than that of the first surface in order to collect the incident light in a shorter distance. The formation of this curved surface can eliminate the characteristic change due to the influence of the axial deviation tolerance of the opposing surface by bringing the end faces of the optical transmission body into contact with or in proximity to each other.

In the above configuration, when the lamp 6c is turned on, the light emitted by the lamp 6c passes through the condenser 1 directly or through the reflecting mirror 6a and is condensed on the end face of the end portion 8 of the light transmission body 7. While being incident. At this time, the light guide tube 2
Can prevent the leakage of light to the outside, and can effectively utilize the divergent light as the incident light to the optical transmission body 8 by the integration element, and the incident light amount can be sufficiently secured. Also, the condenser lens 3
Can narrow the beam waist of the emitted light flux and can also collect the direct light and the divergent light directly emitted from the lamp 6c without passing through the reflecting mirror 6a, so that the emitted beam intensity can be further increased. Become. That is, the surface 3b of the condenser lens 3 on the side facing the lamp 6 with the reflecting mirror is
Since the curvature is small (the protrusion to the outside with respect to the surface 3a is large), as shown in FIG. 3, by the reflecting mirror 6a that blocks most of the light flux emitted from the lamp 6 with a reflecting mirror. The incident angle of the reflected light A with respect to the condenser lens 3 becomes almost vertical (incident angle ≈ 0 °), and the Fresnel reflection loss on the incident surface becomes a small value that can be ignored, so that the emitted beam intensity is strong and the beam waist is high. It is possible to obtain a light flux that is narrowed. On the other hand, with respect to the direct light and the divergent light from the lamp 6c, the incident angle on the condenser lens 3 becomes large and the Fresnel reflection loss increases, but the direct light and the divergent light have a ratio of being a total luminous flux. Since it is small, the effect of condensing a component that can hardly be focused unless the condensing lens 3 is used is greater, so that it contributes to the increase of the emitted beam light as a whole.

That is, by reducing the Fresnel reflectance of the entrance surface of the condenser lens 3, the condensing efficiency is increased as compared with a normal convex lens having a large curvature with both surfaces having the same curvature.

Further, by changing the curvatures of both surfaces of the condenser lens 3, a focal length shortening effect is produced, the focal length can be shortened, and the space factor is improved.

Next, a second embodiment will be described. Although not shown in the drawing, the surface of the condenser lens 3 is coated with a heat ray reflective coating, and the other structure is the same as that of the first embodiment. As a result, the infrared rays can be prevented from entering the light transmission body 7, so that the introduction of heat to the optical control device or the like arranged in the light transmission body 7 can be blocked as necessary, and the durability is improved. Can be achieved. That is, when a heat ray reflective coating is applied to the lens surface 3b, the characteristic common to the derivative coating is that when the incident angle of the light ray is inclined from the vertical (= 0 °) with respect to the condenser lens 3, it is reflected. The index characteristic has a property of shifting to the short wavelength side. Therefore, for example, in the reflecting mirror 6a having a heat ray transmitting coating, the direct light and the divergent light from the lamp 6c which is not transmitted through the heat ray backward are reflected by slightly shifting the heat ray wavelength to the visible long wavelength side, so that the heat ray is not cut. The effect will be enhanced.

Further, in the third embodiment, although not shown in the figure, both surfaces 3a and 3b of the condenser lens 3 are coated with heat ray reflective coating. In the dielectric coating, the heat reflection property of the dielectric multilayer film is determined by the optical film thickness (refractive index x film thickness) and the number of layers, but at the same time, the condition that the transmittance in the visible light region is good is required. Must also be met. In that case, the coating of only one surface of the condenser lens 3 cannot sufficiently cut near infrared rays having large radiant energy. Generally, in the heat ray reflective coating, the reflectance is raised from around 700 nm on the visible long wavelength side, and the heat ray in the wavelength range up to about 1100 nm is cut. Therefore, the effect of cutting the heat rays cannot be obtained in the wavelength range of 1100 nm or more. However, depending on the characteristics of the optical control device that is combined with the optical transmission body 7 as necessary, it may be 1700 like a liquid crystal shutter.
For some, it is desirable to cut the heat rays down to about nm. Therefore, by applying heat ray reflective coatings having different characteristics to the both surfaces 3a and 3b of the condenser lens 3,
By changing the reflection characteristics of the surfaces 3a and 3b and combining them, it is possible to achieve a comprehensive broadband near infrared cut.

Further, in the first embodiment, the condenser lens 3 may be made of heat absorbing glass, which also makes it possible to eliminate the incidence of heat rays on the transmission body 7.

Furthermore, in the second and third embodiments, the condenser lens 3 may be made of heat-absorbing glass, and in this case, the heat-absorbing glass and the heat-ray reflecting coating synergistically act to further cut the heat ray. The effect can be obtained.

[Effect of device]

As described above, according to the condenser of the present invention, the condenser lens is disposed in the light guide tube having a predetermined taper angle that does not interfere with the beam emitted from the lamp with the reflecting mirror, and the condenser lens surface is When the outgoing beam is incident on the lens surface with a predetermined directionality, it reduces the incident loss, increases the focused beam of the outgoing beam of the lamp with a reflector, and The light beam waist can be narrowed down, and the outgoing beam can be efficiently guided to the end surface of the optical transmission body having a small diameter on the light incident surface.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a sectional explanatory view showing a state in which a lamp with a reflecting mirror and an optical transmission body are combined, and FIG. 3 is an incident beam of an outgoing beam to the optical transmission body. It is explanatory drawing which shows a state. Explanation of reference numerals 1 ... Condenser with lens, 2 ... Light guide tube 3 ... Condensing lens, 3a, 3b ... Surface 4 ... Large-diameter aperture, 5 ... Small-diameter aperture 6 ... Reflector With lamp, 6a ... Reflecting mirror 6b ... Filament, 6c ... Lamp 7 ... Optical transmitter, 8 ... End 10 ... Step, A ... Reflected light .alpha .... taper angle

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-50-10646 (JP, A) JP-A-60-72106 (JP, A) Actual development Shou-50-115043 (JP, U) Practical application Sho-56- Microfilm (JP, U) of the contents and drawings attached to the application for No. 142501 (Shokai Sho 58-47803)

Claims (4)

[Scope of utility model registration request] 1. A light source having a concave reflecting mirror formed of a spheroidal surface, a large-diameter opening having a predetermined taper angle, in which the light source is located, and a small-diameter opening in which an optical transmission body is located. A light collector having a substantially truncated conical light guide tube and a condenser lens disposed in the light guide tube, wherein the light source has a light emitting unit at a first focus of the spheroid. Having, condensing the light flux to the second focus of the spheroid, the condensing lens, the first surface on which the light source is located is a substantially concentric curved surface centered on the second focus, The curvature of the curved surface is formed in a convex lens shape so as to be within the range from the large-diameter opening portion of the light source to the second focus position, and the light flux from the light source is incident on the first surface substantially vertically. And a convex lens in which the second surface on which the optical transmission body is located is larger than the curvature of the first surface. A light collector characterized by being formed in a zigzag shape. 2. The condensing lens has a heat ray reflective coating on one of the surface facing the large diameter opening and the surface facing the small diameter opening to balance the heat ray cutting characteristic and the visible light transmission loss. The light collector according to claim 1, which can be arbitrarily selected. 3. The heat condensing lens has heat-reflecting coating on both surfaces facing the large-diameter opening and the small-diameter opening, and the balance between the heat-ray cutting property and the visible light transmission loss can be arbitrarily selected. The concentrator according to claim 1, wherein the utility model registration is possible. 4. The utility model registration claim 3 in which the heat ray reflective coatings on both surfaces of the condenser lens are shifted in wavelength ranges different from each other so that heat ray cut characteristics can be obtained in a wide band. The light collector described.