JPH01105224A - Stroboscopic device - Google Patents

Abstract

PURPOSE:To keep the light distribution character of a reflected luminous flux which lights an object satisfactory and to miniaturize a second reflected surface body by narrowing the irradiating angle of the reflected luminous flux of a first reflecting surface body and magnifying the irradiating angle of the reflected luminous flux of the second reflecting surface body. CONSTITUTION:Light from a flash discharge tube 1 passes through an aperture 3 and makes incident on a reflecting mirror 8 directly or after reflected by a reflector 2. At this time, to minimize the irradiating angle, the reflector 2 is formed into a recessed shape so that at least one of two cross sections which orthogonally intersect each other except a cross section perpendicular to the proceeding direction of the reflect luminous flux, turns into a secondary curve or a curve similar to it. On the other hand, the reflecting mirror 8 is formed into a projecting shape so that at least one of two cross sections orthogonally intersect each other, turns into the curve of the second order or a curve similar to it. And the reflecting mirror 8 enlarges the irradiation of the light making incident from the aperture 3, and sends the appropriate light of the irradiating angle to the object 4. Thus the light distribution character of the reflected luminous flux which lights the object 4 is kept satisfactory and the reflecting mirror 8 can be miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to an improvement in a strobe device used in an optical instrument such as a camera.

(Background of the Invention) Conventionally, this type of strobe device, as shown in FIG. Most of them emitted light toward subject 4. Further, as an improvement on the one shown in FIG. 4, the applicant of the present application proposed a strobe device as shown in FIG. 5 in Japanese Utility Model Application Publication No. 157230/1983 in order to make it more compact. The one shown in FIG. 85 is characterized in that the aperture 3 of the reflector 2 faces in a direction substantially perpendicular to the direction of the subject 4. The light emitted from the flash discharge tube l is reflected directly or after being reflected by the reflector 2, passes through the opening 3 of the reflector 2, and is reflected by the movable reflector 5 toward the subject 4. With this configuration, by rotating the lightweight and easy-to-move reflector 5 without directly moving the flash discharge tube 1 or the reflector 2, it is possible to direct the strobe light toward the subject 4 from a position away from the photographing optical axis of the camera. can be reached.

If the photographing optical axis of the camera and the optical axis of the strobe are close to each other, if the subject 4 is a human, the eyes may appear red.
The strobe device shown in FIG. 5 can prevent red eyes from appearing in the image. However, in the strobe device shown in FIG. 5, the light beam from the flash discharge tube 1 and the reflector 2 spreads and travels, so the reflector 5 has to be large. In other words, in FIG. 6, in order to maintain sufficient light distribution characteristics in the vertical direction, it is necessary to reflect all of the luminous flux a illuminating the upper part of the subject 4 and the luminous flux A illuminating the lower part towards the subject 4 side. In particular, subject 4
In order to reflect all the luminous flux a illuminating the upper part of the camera in the direction of the subject 4, the single reflecting mirror 5 had to be made extremely large. In FIG. 6, 6 is the case of the strobe device, 7 is the camera body, and 5' is the unused position of the reflector 5 that covers the case 6 when the strobe is not used.

(Object of the Invention) An object of the present invention is to provide a strobe device that solves the above-mentioned problems and can reduce the size of the reflective surface while maintaining good light distribution characteristics of the reflected light flux that illuminates the subject. It is.

(Features of the invention) In order to achieve the above object, the present invention provides a flash discharge lamp,
a first reflective facepiece that reflects the luminous flux emitted from the flash discharge lamp; and a second reflective facepiece that reflects the direct luminous flux from the flash discharge lamp and the reflected luminous flux from the first reflective facepiece; The first reflective surface body is formed into a concave surface such that at least one of its two orthogonal cross sections has a cross-sectional shape that is a quadratic curve or a curve close to it, Formed into a convex surface such that at least one cross-sectional shape is a quadratic curve or a curve close to it,
The first reflective surface body is fixed so as to face in the opposite direction to the subject, and the second reflective surface body is placed between the use position and the first reflective surface body.
The reflecting face piece is arranged so as to be able to rotate between a non-use position covering the reflective face piece, thereby narrowing the illumination angle of the reflected light beam of the first reflective face piece and expanding the illumination angle of the reflected light beam of the second reflective face piece. It is characterized by being made to do.

(Example of the invention) FIG. 1 shows an embodiment of the invention.

The same parts as in FIG. 6 are indicated by the same symbols, 1 is a flash discharge tube, 2 is a reflector corresponding to the first reflective surface of the present invention, 3 is an opening of the reflector 2, and 4 is a subject. , 6 is a case of the strobe device, 7 is a camera body, a is a light flux that illuminates the upper part of the subject 4, and b is a light flux that illuminates the lower part. 8 is a reflecting mirror corresponding to the second reflecting surface of the present invention, and 8' indicates the unused position of the reflecting mirror 8 that covers the box 6 when the strobe is not used. It is fixed to the camera body 7 so as to face in the opposite direction.

The reflecting mirror 8 is attached to a shaft 9 so as to be rotatable between a use position shown by a solid line and a non-use position 8' shown by a dotted line that covers the box 6.

The light emitted from the flash discharge tube 1 enters the reflecting mirror 8 through the opening 3 either directly or after being reflected by the reflecting umbrella 2.
At this time, in order to make the reflector 8 as small as possible, the shape of the reflector 2 is orthogonal except for the cross section perpendicular to the traveling direction of the reflected light beam, so that the light emitted from the aperture 3 has an irradiation angle as small as possible. The details of the shape of the zero reflector 2 will be described later, in which it is important that at least one of the two cross sections be formed into a concave surface that is a quadratic curve or a curve close to it.

The reflecting mirror 8 is formed into a convex surface such that at least one of the two orthogonal cross sections excluding the cross section perpendicular to the traveling direction of the reflected light beam is a quadratic curve or a curve close to the quadratic curve. FIG. 2 shows an example of the shape of the reflecting mirror 8.
In A), the cross-sectional shape in the X direction is a straight line among the two orthogonal cross sections, and the y
A convex surface whose cross-sectional shape in the direction is a quadratic curve such as a circle or a parabola is shown, and Fig. 2 (B) shows a convex surface whose cross-sectional shape in both the X direction and the y direction is a quadratic curve. The reflecting mirror 8 having such a shape functions to widen the irradiation angle of light incident from the aperture 3, and allows light at an appropriate irradiation angle to reach the subject 4. As can be seen from a comparison with FIG. 6, the reflecting mirror 8 can be made smaller than the reflecting mirror 5.

In order to narrow the irradiation angle of the light emitted from the open product 3, it is desirable to make the cross-sectional shape of the reflector 2 as shown in FIG. The cross-sectional shape was set to an ellipse in order to illuminate the area. In FIG. 1, when the optical axis direction of the reflector 2 is the X axis, the direction perpendicular to the X axis is the y axis, the paraxial radius of curvature is R, and the centrality is e, the quadratic curve can be expressed as. As is well known, 0<e<
1...Ellipse e=1...
... Parabola e > 1 ... Hyperbola, and in order to narrow the irradiation angle of the light emitted from the aperture 3, the cross section of the reflective umbrella 2 should be 0, 8<e<1, 2 = ( A shape that satisfies (1) and is close to a parabola is desirable. If the lower limit of equation (1) is exceeded, it becomes a normal ellipse and the irradiation angle becomes too wide. If the upper limit is exceeded, the irradiation angle is similarly too wide.

Note that the shape of the cross section of the reflector 2 perpendicular to the cross section shown in FIG. 1 may be a straight line or a quadratic curve.

In order to narrow the irradiation angle from the aperture 3, it is effective to move the flash discharge tube l closer to the apex of the reflector 2.

Furthermore, as shown in FIG. 3, it is also effective to provide the aperture 3 with a convergent Fresnel lens 10 or a normal lens.

In order to make the reflecting mirror 8 smaller, it is preferable to direct the optical axis of the strobe device, which connects the flash discharge tube 1 and the center of the aperture 3, in the direction opposite to the direction of the subject 4, as shown in FIG.

(Modification) The reflecting surface of the reflecting mirror 8 may be Fresnel-shaped, and the flash discharge lamp is not limited to a rod-shaped one, but may be spherical.

(Effects of the Invention) As explained above, according to the present invention, a flash discharge lamp,
a first reflective facepiece that reflects the luminous flux emitted from the flash discharge lamp; and a second reflective facepiece that reflects the direct luminous flux from the flash discharge lamp and the reflected luminous flux from the first reflective facepiece; The first reflective surface body is formed into a concave surface such that at least one of its two orthogonal cross sections has a cross-sectional shape that is a quadratic curve or a curve close to it, Formed into a convex surface such that at least one cross-sectional shape is a quadratic curve or a curve close to it,
The first reflective surface body is fixed so as to face in the opposite direction to the subject, and the second reflective surface body is placed between the use position and the first reflective surface body.
The reflecting face piece is arranged so as to be able to rotate between a non-use position covering the reflective face piece, thereby narrowing the illumination angle of the reflected light beam of the first reflective face piece and expanding the illumination angle of the reflected light beam of the second reflective face piece. By doing so, the second reflective surface body can be made smaller while maintaining good light distribution characteristics of the reflected light flux that illuminates the subject.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, FIG. 2 is a perspective view showing an example of a reflecting mirror according to one embodiment of the present invention, and FIG. 3 is a cross-sectional view showing another embodiment of the present invention. 4 is a schematic diagram showing an example of a conventional strobe device, FIG. 5 is a schematic diagram showing another example of a conventional strobe device, and FIG. 6 is a sectional view showing the conventional device shown in FIG. 5. . 1...Flash discharge tube, 2...Reflector, 3
...Aperture, 4...Subject, 6...
...Box, 7...Camera body, 8...
Reflector, 9...axis, lO...Fresnel lens.

Claims (1)

[Claims] (1) A flash discharge lamp, a first reflective face piece that reflects the luminous flux emitted from the flash discharge lamp, and a second reflective face piece that reflects the direct light flux from the flash discharge lamp and the reflected light flux from the first reflective face piece. a reflective surface body, the first reflective surface body is formed into a concave surface such that at least one of its two orthogonal cross sections has a cross-sectional shape that is a quadratic curve or a curve close to it; , at least one of the two orthogonal cross sections is formed into a convex surface such that the cross-sectional shape is a quadratic curve or a curve close to it, and the first reflective surface body is fixed so as to face in the opposite direction to the subject; A strobe device in which the second reflecting surface is arranged so as to be rotatable between a use position and a non-use position covering the first reflection surface.