JP3231379B2 - Strobe reflector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strobe reflector for reflecting a light beam emitted from a light source on a reflecting surface thereof.

[0002]

BACKGROUND OF THE INVENTION Strobe devices are generally
A reflecting surface (umbrella) is provided on the back of the light source, and a combined light beam of direct light from the light source and light reflected by the reflecting surface is emitted toward the subject. Since an elliptical reflecting mirror is conventionally used in the strobe device, an image is formed once through, for example, a Fresnel lens (condensing lens) provided on the front surface of the reflecting mirror.
When the light source is the first focus, an image (second focus) of the light source is formed in front of the light source.

[0003] By the way, since the reflecting mirror used in the conventional strobe device has an elliptical shape, its attachment to a holding member for holding the reflecting mirror, such as a strobe main body or a camera, is poor, and the work is difficult. In addition, there is a problem that the processing accuracy is difficult to obtain due to the complicated shape.
Further, according to the elliptical reflecting mirror, when the light source is housed in the rear part of the inner surface, the curvature of the outer peripheral surface of the light source is different from that of the inner surface of the housing, so that the mounting property is poor.
Therefore, as shown in FIG. 4, a configuration in which a concave portion 10 having the same curvature as that of the outer peripheral surface of the light source 11 is formed in the rear portion of the inner surface of the reflecting mirror and the light source 11 is accommodated in the concave portion 10 can be considered. According to the method, there occurs a problem that reflected light, which is difficult to predict, is emitted on the reflecting surface of the connecting portion 9a between the reflecting mirror 9 and the concave portion 10 having different curvatures.

[0004]

An object of the present invention is to provide a strobe reflecting mirror which solves the above-mentioned problems with a strobe reflecting mirror, improves the attachment of a light source, has a simple shape, and can easily provide processing accuracy. It is intended to provide.
Further, the present invention improves the mountability to a holding member for holding a reflecting mirror, such as a strobe main body or a camera, and can reduce a space for mounting the same, and further prevents a problem that reflected light which is difficult to predict due to a concave portion near a light source is emitted. It is an object of the present invention to provide a strobe reflector that can be eliminated.

[0005]

SUMMARY OF THE INVENTION The present invention that achieves the above objects, therefore,
In a strobe reflecting mirror for reflecting a light beam emitted from a light source on its reflecting surface, the reflecting surface has a sectional shape.
And an outer periphery of the light source centered on a light emitting point of the light source.
And an arc portion having substantially the same curvature as that described above, and a continuous portion extending from the arc portion and extending in a tangential direction in contact with the arc portion.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
FIG. 1 shows a first embodiment of a reflector 12 for a flash according to the present invention. The figure shows a light source (xenon tube) 1
1 shows a cross section along the illumination optical axis O passing through the center of the first light source 11. A second reflection surface (continuous portion) 12 a connected to the first reflection surface (arc portion) 13 has the light source 11 as a center. It is configured as a pair of flat reflecting surfaces arranged above and below the drawing. In the figure, reference numeral 14 denotes a holding member for holding the reflecting mirror 12, such as a flash body or a camera.

The light source 11 is formed in a cylindrical shape, and is housed in a concave portion 16 formed at the rear of the optical axis of the reflecting mirror 12 so as to be perpendicular to the plane of FIG. The inner surface of the concave portion 16 has the same curvature as the outer peripheral surface of the light source 11 and has a shape along the cylindrical light source 11. In other words, the recess 16 is located behind the light source 11 on the optical axis.
It is configured as an arc-shaped first reflecting surface 13 located on a concentric circle centered on one light emitting point.

The second reflecting surface 12a has a substantially straight cross section, and is located on a tangent to a concentric circle centered on the light emitting point of the light source 11. In the present embodiment, the concentric circle coincides with the outer peripheral surface of the light source 11 and the first reflecting surface 13 having a circular arc cross section of the concave portion 16. Further, the second reflecting surface 12a can be configured as a perfect straight line. Second reflective surface 1
The front end of 2 a is in contact with the upper and lower ends of the Fresnel lens 17 attached to the front of the holding member 14 at an angle A (for example, 60 °).

According to the strobe reflecting mirror 12 having the above-described structure, since the second reflecting surface 12a is formed in a substantially linear shape, it is attached to a holding member for holding the reflecting mirror, such as a strobe main body or a camera. And the accuracy can be improved. In addition, since unpredictable light rays are not emitted at the position where the light source 11 is attached to the reflecting mirror 12, uneven light distribution due to unpredictable light rays hardly occurs. This is because the luminous flux emitted from the light source 11 proceeds as follows. That is, of the light beams emitted from the light emitting point of the light source 11, the light beam reflected by the second reflection surface 12a located on the upper side in FIG. 1 advances as indicated by p in the figure. Further, among the light beams emitted from the light emitting point of the light source 11, the light beam reflected by the lower second reflection surface 12a proceeds as shown by q in the drawing.

In the reflecting mirror 12 having such a reflecting characteristic, the second reflecting surface 12a is smooth because the second reflecting surface 12a is connected as a tangent to the arc of the first reflecting surface 13 so that the second reflecting surface 12a is smooth. Since there is no portion where the curvature changes abruptly like the connecting portion 9a, it is possible to irradiate uniform light with no difficult-to-predict light and little possibility of uneven light distribution. The reflecting mirror 12 is provided between the light emitting point of the light source 11 and the second reflecting surface 12a.
At points a and b at optically conjugate positions with respect to
This is equivalent to the presence of a virtual image of the light emitting point of the light source 11, whereby the light beams are emitted from the light sources 11 'and 11 "having the points a and b as the light emitting points, respectively. Further, since the light beams p and q do not form an image after passing through the Fresnel lens 17 and can be directly irradiated in the same direction, a uniform light distribution that does not cause unevenness near the center can be obtained. Fresnel lens 1
7, the upper and lower second reflecting surfaces 12
In addition to those reflected by a, the light includes direct light directly emitted from the light source 11 forward (to the left in FIG. 1), and furthermore, in the direction directly opposite to these light beams (to the right in FIG. 1). Is reflected by the first reflecting surface 13 and is radiated forward together with the luminous flux radiated forward.

FIG. 2 shows a second embodiment. Although the reflecting mirror 12 of this embodiment has an elliptical shape, unlike the conventional reflecting mirror 9 shown in FIG. 4, a concave portion 16 (first reflecting surface 13) is formed at a joint portion between the arc tube 11 and the rear portion of the reflecting mirror 12. Further, a second reflecting surface 12a common to the first embodiment and coinciding with a tangent of a concentric circle of the light source 11 is formed in a portion from the first reflecting surface 13 to the elliptical reflecting surface 12b. According to the reflecting mirror 12 having such a shape, it is possible to reduce unevenness at the time of irradiation, which is caused by the conventional elliptical reflecting mirror, and to improve light distribution characteristics. In the case of a conventional elliptical reflector,
Installation on devices that require a strobe, such as cameras,
Although there was no straight portion, it was difficult. However, since such a shape has a straight portion, mounting becomes easy and accuracy is improved. Further, as described above, since there is no sharp change in curvature as in the connecting portion 9a shown in FIG.
There are no unpredictable rays.

FIG. 3 shows a third embodiment. 1 is different from the reflecting mirror 12 of FIG.
2c, the diameter of the light source (xenon tube) 11 is reduced, and the supporting spacer 20 is interposed between the light source 11 and the concave portion 16 (first reflection surface 13). It is a point. The joint 12c is a Fresnel lens 1
7, the second reflecting surface 12a is formed at an angle B (for example,
57 ゜). The spacer 20 itself is made of a transparent material, but is not limited thereto.
It is also possible to use one having a reflection surface formed in a portion that comes into contact with the light source 11. Even with the reflecting mirror 12 having such a shape, the same light distribution characteristics as those of the reflecting mirror 12 of FIG. 1 can be provided.

Conventionally, an elliptical and cylindrical light source is mounted, so that there is a portion where the curvature changes abruptly like the connecting portion 9a shown in FIG. As described in the above, according to the reflector 12 of the present invention, since the reflector has a smooth shape from the mounting portion of the light source 11 to the entire reflector, it is possible to eliminate problems such as reflected light that is difficult to predict. it can. In addition, since the reflecting mirror 12 has a straight line portion, the mounting of the reflecting mirror 12 to a member holding the reflecting mirror, such as a strobe main body or a camera, is easier and more accurate than conventional ones. Become. In particular,
In a reflecting mirror having a substantially linear second reflecting surface 12a,
It is more compact than the conventional elliptical shape (indicated by the two-dot chain line in FIG. 5). In addition, since the shape of the reflecting mirror 12 is determined by the linear second reflecting surface 12a and the opening angle thereof, inspection and verification can be easily performed.

[0014]

As described above, the reflecting mirror of the strobe device according to the present invention has an arc portion having a cross-section centered on the light emitting point of the light source and having substantially the same curvature as the outer periphery of the light source .
Continuous to the circular arc portion, extending tangentially in contact with the arc portion
The light source can be stably attached to the reflecting mirror because of the continuous portion. Further, the reflecting mirror of the present invention has an arc portion and
Since the continuous portion is smoothly connected , the shape is simplified, the processing accuracy can be easily obtained, the mountability to the strobe main body can be improved, and the mounting space can be reduced. Furthermore, the reflector of the present invention, because the arc portion and the continuous portion are smoothly connected in the tangential direction of the arc portion , conventionally, unpredictable reflected light generated near the concave portion behind the light source of the reflector, It can be reliably eliminated.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along an illumination optical axis, showing a first embodiment of a strobe reflecting mirror according to the present invention.

FIG. 2 is a sectional view taken along the illumination optical axis, showing a second embodiment of a strobe reflecting mirror according to the present invention.

FIG. 3 is a sectional view taken along an illumination optical axis, showing a third embodiment of a strobe reflecting mirror according to the present invention.

FIG. 4 is a sectional view showing a concave shape of a conventional elliptical reflecting mirror.

FIG. 5 is a cross-sectional view comparing the shapes of a strobe reflecting mirror according to the present invention and a conventional elliptical reflecting mirror.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 11'11 "Light source 12 Reflecting mirror 12a Second reflecting surface (continuous portion) 13 First reflecting surface (arc portion) 14 Holding member 17 Fresnel lens O Illumination optical axis

Claims (5)

(57) [Claims] 1. A strobe reflector for reflecting a light beam emitted from a light source on a reflection surface thereof, wherein the reflection surface has a cross-sectional shape that is substantially the same as the outer periphery of the light source centered on a light emitting point of the light source.
An arc portion having a curvature, and a tangential direction continuing from the arc portion and extending tangentially to the arc portion.
A reflector for a strobe, characterized by having a continuous portion that extends . 2. A strobe reflector according to claim 1.
Further, the continuous portion is an ellipsoidal reflector for an electronic flash. 3. A strobe reflector according to claim 1.
Between the light source and the arc of the reflecting surface.
Reflector for strobe with interposed. (4) The strobe reflector according to claim 3.
The spacer is a strobe made of a transparent material.
Reflector. (5) The strobe reflector according to claim 3.
The part of the spacer that contacts the light source has a reflective surface.
A reflector for a strobe with a hole.