JPH0718087Y2 - reflector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a reflector plate having a bowl shape and having an inner peripheral surface as a reflecting surface.

[Prior Art] Generally, as a reflecting surface of this type of reflecting plate, a paraboloid of revolution is used as shown in FIG. 3, the light source 3 is an ideal point light source, and inside the reflecting plate body 1. When the light beam is present at the focal position of the reflecting surface 5 provided in, the parallel light beam can be obtained. However, the actual light source 3 has a size, particularly when it has a filament 4 long in the optical axis direction like a general halogen bulb, and the filament 4 is formed in a coil shape, Since light and darkness occurs at each position of the filament 4, there is a problem that light and darkness also occurs on the irradiation surface. That is, as shown in FIG.
When the filament is viewed from one point, the filament image is formed as it is on the irradiation surface, so that the unevenness of the filament seen from each position of the reflecting surface 5 is reflected as it is on the irradiation surface, resulting in ring-shaped unevenness. .

On the other hand, as shown in FIGS. 5 and 6, the reflecting surface 5 is divided into small reflecting surfaces 6'having substantially the same area over substantially the entire surface, and each small reflecting surface 6'is made into a flat surface. There is provided a polyhedral reflector. In this reflecting plate, the focus position of the reflecting surface 5 as a whole is slightly expanded, so that the image of the filament 4 on the irradiation surface is also blurred, and unevenness on the irradiation surface can be alleviated.

[Problems to be Solved by the Invention] However, in the above-mentioned configuration, the extent of the focal point spread by one small reflecting surface is relatively small, so that for the filament having a relatively long length along the optical axis, the irradiation surface It was not possible to eliminate the unevenness in the area.

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and provides a reflector which prevents unevenness on the irradiation surface even when a light source having a filament long in the optical axis direction is used. It is what

[Means for Solving the Problems] In the present invention, in order to achieve the above object, the reflecting surface is divided into a large number of small reflecting surfaces over substantially the entire surface, and each small reflecting surface is provided inside the reflecting plate body. In addition to having a protruding spherical shape, the radius of curvature is made smaller as it approaches the inner bottom portion from the opening side.

[Operation] According to the above configuration, since each small reflection surface is a spherical shape protruding inside the reflection plate body, no focus is formed on each small reflection surface, and the filament image is not formed on the irradiation surface. Therefore, unevenness of the irradiation surface is prevented. In addition, since each small reflecting surface is formed so that the radius of curvature that approaches the inner bottom portion of the reflector main body becomes small, the portion facing the irradiation surface has a shape close to the diffuse reflection surface, and unevenness on the irradiation surface is caused. The effect of eliminating it will be even higher.

That is, by making the radius of curvature of the small reflecting surface of the inner bottom portion where the angle of looking up the unit length of the light source from the reflecting surface becomes large (that is, increasing the curvature), the inner bottom portion that is easily affected by the unevenness of the light output from the light source. That is, the diffusivity of the light is increased, and as a result, the unevenness of the light output of the light source is less likely to be reflected on the irradiation surface.

[Example] As shown in FIG. 1, the reflector main body 1 is formed in a bowl shape, and the inner peripheral surface thereof serves as the reflecting surface 5. A socket 2 is attached to the outer surface of the bottom of the reflector main body 1, and a light source 3 such as a halogen bulb is held in the socket 2. The light source 3 is arranged so that the filament 4 is located inside the reflector main body 1, and the filament 4 is formed in a long shape along the optical axis of the reflecting surface 5. The reflecting surface 5 is divided into a large number of small reflecting surfaces 6 over the entire surface, and each small reflecting surface 6 is divided into the second small reflecting surfaces 6.
As shown in the figure, it has a spherical shape protruding inside the reflector main body 1. Therefore, each small reflecting surface 6 has a substantially hexagonal shape, and the reflecting surface 5 is formed in a honeycomb shape as a whole.
Each small reflecting surface 6 is formed so that the radius of curvature becomes smaller as it approaches the inner bottom portion from the opening of the reflecting plate main body 1, and the small reflecting surface 6 on the inner bottom side is closer to the opening side. The area is smaller than 6. That is, the reflective surface 5
Is formed so that the inner bottom portion is closer to the diffuse reflection surface. Here, the reflector main body 1 is, for example, a synthetic resin molded product, and the mold can be cut at the portion corresponding to each small reflection surface 6, so that the mold can be relatively easily prepared.

According to the above configuration, each small reflecting surface 6 is spherical,
Since it projects inside the reflector main body 1, each small reflecting surface 6
Since the focal point is not formed on the first reflection surface, the filament 4 is not reflected on the small reflection surface 6, and the focal point is not formed on the reflection surface 5 as a whole, so that unevenness on the irradiation surface hardly occurs. In particular, at the inner bottom of the reflecting surface 5 facing the irradiation surface, the small reflecting surface 6 has a small radius of curvature,
Since the area of each small reflecting surface 6 is also small, reflection similar to diffuse reflection is performed, and the image of the filament 4 is erased by the overlapping of the reflected light, and the effect of preventing unevenness on the irradiation surface is further enhanced. Also, regarding the light distribution curve,
The divergence of the beam is relatively large, and the uneven illuminance is reduced as a whole.

[Advantage of the Invention] As described above, the present invention divides the reflecting surface into a large number of small reflecting surfaces over substantially the entire surface, and each small reflecting surface is formed into a spherical shape projecting inside the reflecting plate body. The radius of curvature becomes smaller as it approaches the inner bottom from the opening side, and since each small reflection surface is a spherical shape that protrudes inside the reflector main body, a focus is formed on each small reflection surface. Therefore, the filament image is not formed on the irradiation surface. Further, since each small reflecting surface is formed so that the radius of curvature becomes smaller as it gets closer to the inner bottom portion of the reflecting plate main body, a state close to diffuse reflection can be obtained at the portion facing the irradiation surface. That is, there is no reflection of an image on the small reflection surface, and since reflection close to diffuse reflection is performed at the inner bottom portion of the reflection surface, unevenness on the irradiation surface is prevented. In addition, since no focus is formed on the entire reflecting surface, the rise of brightness at the peripheral portion of the light distribution curve becomes gentle,
It is possible to perform soft illumination by blurring the boundary between the non-illuminated part and the illuminated part.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a cross-sectional view of a main part of the same, FIG. 3 is a cross-sectional view showing a conventional example, FIG. 4 is an operation explanatory view of the same, FIG. FIG. 6 is a perspective view and a sectional view showing another conventional example. 1 ... Reflector body, 2 ... Socket, 3 ... Light source, 4 ...
… Filament, 5 …… Reflecting surface, 6 …… Small reflecting surface.

Claims (1)

[Scope of utility model registration request] 1. A reflector main body having a bowl shape and an inner peripheral surface serving as a reflecting surface, wherein the reflecting surface is divided into a large number of small reflecting surfaces over substantially the entire surface, and each small reflecting surface reflects. A reflector plate having a spherical shape protruding inward of the plate body, and having a radius of curvature that decreases as it approaches the inner bottom portion from the opening side.