JP3299780B2 - Flash mechanism for camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a strobe mechanism for a camera.

[0002]

2. Description of the Related Art FIG. 16 shows the structure of a strobe mechanism for a camera of this type. In the drawing, reference numeral 1 denotes an Xe tube as a light emitting source, and 2 denotes a cross-sectional shape formed by a part of a quadratic curve such as an ellipse. The reflecting mirror 3 is a light emitting window. The strobe having such a configuration is incorporated in the strobe unit 4 as shown in FIG. 17, and the longitudinal direction thereof is perpendicular or parallel to the horizontal plane of the camera 5 in order to irradiate the photographing surface of the subject with uniform light. Had been placed.

[0003]

By the way, if the strobe can be tilted with respect to the horizontal plane of the camera and arranged at an arbitrary position inside or outside the camera body, it is advantageous in terms of the design of the camera. However, in this case, there is a problem that the light distribution becomes oblique, and the subject cannot be irradiated with uniform light, and the light amount becomes uneven. In this case, it is also possible to change the light distribution by giving a refracting power to the light emission window of the strobe arranged in a tilted manner to correct the light distribution in the subject, but in the case of a strobe corresponding to shooting at a wide angle of view, , Xe
When the light emitted from the tube enters the light emitting window, there is a problem that the light is lost due to total reflection.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to correct the light distribution with a small loss of light quantity, and to make it possible to correct the light distribution with respect to the horizontal plane of the camera. An object of the present invention is to provide a strobe mechanism for a camera that can appropriately illuminate a subject even when the camera is inclined.

[0005]

A strobe mechanism for a camera according to the present invention includes a light emitting member and a reflecting member formed along the longitudinal direction of the light emitting member and having a substantially concave cross section. A point sequence in which the longitudinal direction is provided at an angle with respect to the horizontal plane of the camera, and the vertex of the concave shape in each cross section of the reflecting member is made continuous along the longitudinal direction of the reflecting member; A non-parallel array of points formed by making the focal point at the finite position of the concave shape in each cross section continuous along the longitudinal direction of the reflective member, and irradiating the reflected light continuously along the longitudinal direction of the reflective member It is characterized by having been changed to. Further, the camera strobe mechanism according to the present invention is provided such that the longitudinal direction of the light emitting member is formed at an angle with respect to the horizontal plane of the camera, and the light emitting axis of the light emitting member has a concave shape in each cross section of the reflecting member. A focal point at a finite position is provided in a non-parallel manner to a series of points made continuous along the longitudinal direction of the reflecting member, and the irradiation direction of the reflected light is continuously changed along the longitudinal direction of the reflecting member. It is characterized by having.

The "concave focus of each section" referred to in the claims means a point at which light emitted from a light-emitting member and which reaches a subject via a reflective member having such a section is concave. Say. For example, the focal point of the reflected light when the light emitted from the light emitting member is incident on the reflective member having a concave cross section, or the focal point of the reflected light when the parallel light flux is incident on the reflective member having a concave cross section from the outside It is. The “vertex” refers to the intersection of the normal to the concave shape passing through the focal point of the concave shape in each cross section and the concave shape.

[0007]

The operation of the present invention will be described with reference to the drawings. FIG.
Is a reflecting mirror 12 whose cross-sectional shape of the reflecting surface is a part of an ellipse.
The strobe 10 having the Xe tube 11 disposed in parallel with the longitudinal direction of the reflecting mirror 12 is fixed at a certain angle θ with respect to the horizontal plane of the camera.
Are shown. The Xe tube 11
As shown in FIG. 2, it is arranged on one focal point F1 of an ellipse (indicated by a broken line) forming a cross section of the reflecting mirror 12, and
The light emitted from the Xe tube 11 and reflected by the reflecting surface of the reflecting mirror 12 is once focused on the other focal point F2 of the ellipse and then irradiates the subject. Therefore, when the reflecting mirror 12 is divided into n pieces along the longitudinal direction, assuming that the position of the Xe tube 11 in each cross section is An and the condensing position of the light reflected by the reflecting mirror 12 is Bn, As shown in FIG. 3, they can be represented as positions on the point sequence (A0,... An) and on the point sequence (B0,... Bn). When a line connecting the point sequence (A0,... An) is a light emission axis and a line connecting the point sequence (B0,... Bn) is a light intensity axis, these two axes are parallel on the same plane. Has become.

When the Xe tube 11 is inclined as shown in FIG. 1, that is, the light emission axis (dot sequence (A0,... An)) in FIG.
Is inclined, the light intensity axis (point sequence (B0,... Bn))
Also tilt at the same time, causing the light distribution on the subject to tilt.
Therefore, when the strobe light is tilted, the light distribution on the subject can be made horizontal by tilting the light intensity axis in the direction opposite to the tilt direction of the light emitting axis.

In order to incline the light intensity axis, the focal position in each section of the reflecting mirror may be changed by "twisting" the reflecting surface of the reflecting mirror along the longitudinal direction. With reference to FIG. 4, a method for obtaining the amount of inclination of the light intensity axis will be described. FIG. 3A shows a plane (ABC) that is horizontal to the horizontal direction of the camera.
FIG. 3D is a diagram showing a state in which the emission axis (ab) of the strobe is arranged on D) and illuminates a plane (EFGH) perpendicular to the plane (ABCD). O1 is the center point of the light emission axis (ab).

Now, as shown in FIG. 1B, the emission axis (a-
When b) is inclined with respect to the plane (ABCD) by an angle θ about O1 as an axis, light emitted from the light-emitting axis (ab) is
FGH), the light is distributed obliquely, and this state can be shown by the relationship shown in FIG. 5 and 5, the distance from the light emitting axis (ab) to the surface (EFGH) is d, and the position x on the light emitting axis (ab) from the center O1.
Let x be the distance to 1 and α be the inclination angle required to distribute light emitted from the light-emitting axis (ab) horizontally on the surface (EFGH). From dtanα = xtanθ, α is given by It can be represented by 1). α = tan ⁻¹ [(x / d) tan θ] (1)

Since the light emission axis (ab) can be replaced with a light intensity axis that is inclined at the same time as the inclination of the light emission axis, the amount of inclination of the light intensity axis is also the same as θ expressed by equation (1). .
The inclination of the light intensity axis can be realized by continuously inclining along the longitudinal direction of the reflecting mirror 12 in accordance with the equation (1) at each cross section of the reflecting mirror 12 as shown in FIG. The shape and inclination in each cross section are not limited to those formed by continuous curves, and may be formed by discontinuously approximating a curve with a set of straight lines.

The light reflected by the reflecting mirror 12 is not distributed horizontally at all positions from the closest distance to the maximum reach of the light, but becomes horizontal at a position separated by a certain distance (d). Therefore, the distance and position at which the light is distributed horizontally are determined by the focal length of the camera lens, the guide number, and the shape of the reflecting mirror.

Also, the case where the cross section of the above-described reflecting mirror 12 is formed by a part of an ellipse has been described. However, the shape of the cross section is not limited to the ellipse, and may be one of other quadratic curves including a parabola and a hyperbola. The same applies to the case of a part.

Next, the case where the light distribution is corrected horizontally without changing the shape of the reflecting mirror 12 will be described. The case where all the light emitted from the light emitting axis passes through the light intensity axis when the cross section of the reflecting mirror 12 is formed as a part of the ellipse has been described with reference to the position of the light emitting axis. If this case is considered with reference to the light intensity axis, the inclined light intensity axis is spatially corrected to a horizontal position, and the light emitted from the light emitting axis passes through the position corrected light intensity axis. As described above, even if the light emitting axis relative to the reflecting mirror 12, that is, the relative position of the Xe tube 11, is shifted, the light distribution on the subject can be adjusted. In other words, if it is not necessary to distribute all the light reflected by the reflecting mirror 12 horizontally, it is preferable to shift the light emitting axis located on the point sequence of the focal point from the focal line (FIG. 7). Reference), but the light distribution can be corrected, although approximately.

As shown in FIG. 8 (a), the Xe tube 11 is located on the focal point F1 of a part of the quadratic curve forming the cross section of the reflecting mirror 12.
Are arranged, the normal vector P (a ray vector such that the ray emitted from F1 is reflected and passes through F1 again) when the position of the Xe tube 11 is shifted from the focal point F1 to F1 'is As shown in FIG. 2B, while the position of the Xe tube 11 is fixed at the focal point F1, the normal vector Q when the reflecting mirror 12 is rotated around the focal point F1 and the position is shifted is the direction of the normal vector Q. Are almost equal. As shown in FIG. 9A, when the Xe tube 11 is located at the focal point F1 of the reflecting mirror 12, the light L1 emitted from the Xe tube 11 and incident on the vertex R of the reflecting mirror 12 is reflected in the horizontal direction. . On the other hand, as shown in FIG. 3B, the reflected light from the position S on the reflecting mirror 12 when the position of the Xe tube 11 is shifted from the focal point F1 to the focal point F1 'is not emitted horizontally, but is output horizontally. Fired at an angle to the direction. Therefore, in the vicinity of the vertex of the reflecting mirror 12, it is safe to assume that the direction of light reflection is the same when the Xe tube 11 is moved and when the position of the reflecting mirror 12 is shifted. Is moved, the light distribution can be corrected in the same manner as when the reflecting mirror 12 is shifted.

In the peripheral portions U to V of the reflecting mirror 12 distant from the apex shown in FIG. 8, when the Xe tube 11 is moved, the position is shifted as compared with the case where the reflecting mirror 12 is rotated to shift the position. The difference between the line vectors can be large,
The light distribution of the light reflected by the portions U to V cannot be corrected. However, since the amount of light incident on this portion is extremely smaller than that near the vertex, the effect on the light distribution may be ignored. In addition, in order to correct light reflected at the peripheral portion of the reflecting mirror 12, a part of the quadratic curve forming the cross section may be deformed only at the peripheral portion of the reflecting mirror 12. Also in this case, a part of the quadratic curve forming the cross section is not limited to the ellipse, but may be a normal line or a hyperbola. In addition, the Xe tube 11 needs to be at the focal position of the quadratic curve to correct the light distribution. There is no.

[0017]

FIG. 10 is a schematic structural view of a compact camera in which a strobe mechanism for a camera according to the present invention is installed in a camera body. In the figure, 10 is a strobe, 14 is a finder section, 15 is a photographing objective lens, 16 is a film surface, 17
Is a patrone, 18 is a film winding portion, 19 is a long side of the film surface 16 parallel to the horizontal surface 20 of the camera,
The strobe 10 is disposed at a constant inclination angle θ with respect to a horizontal plane 20 of the camera body. Hereinafter, an embodiment of a strobe that can be installed in the strobe 10 and that is suitable for correcting the influence of light distribution due to the inclination of the angle θ will be described with reference to the drawings. It is assumed that the cross section of the reflecting mirror is formed by a part of an ellipse.

First Embodiment FIG. 11 is an external view of a flash mechanism according to a first embodiment. In the figure, 11 is a Xe tube, 12 is a reflecting mirror, and 13 is a light emitting window. The cross section of the reflecting mirror 12 is formed by a part of an ellipse, and the Xe tube 11 is arranged at one focal point of the ellipse in each cross section. In addition, the other focal point of the ellipse in each section is continuously changed along the longitudinal direction of the reflecting mirror 12 so that its position becomes horizontal from the inclined position in order to correct the light distribution. That is, the cross-sectional shape of the reflecting mirror 12 changes continuously along the longitudinal direction of the reflecting mirror 12. Therefore, the point sequence of the vertices of the ellipse and the point sequence of the focal point in each section of the reflecting mirror 12 are non-parallel.

In the strobe having such a shape, the Xe tube 1
1 is reflected by the reflecting surface of the reflecting mirror 12 and irradiates the subject, but since the point sequence of the vertices and the point sequence of the focal point of each section of the reflecting mirror 12 are provided in non-parallel, The light distribution is appropriately corrected, and the subject can be illuminated in a state where there is no unevenness in the light amount. It should be noted that the amount by which the focal position should be corrected for the strobe tilt is given by the above equation (1). Further, as shown in the figure, when the shape of the reflecting mirror 12 is formed by a continuous curved surface, the light emitting window 13 becomes a parallelogram, but the shape of the light emitting window 13 is not corrected for the light distribution of this embodiment. The present invention is not limited to this, and can be arbitrarily formed, for example, in a rectangle or the like. According to this embodiment, it is only necessary to give a certain angle of twist to the conventional reflecting mirror, which is simple in principle. Also,
It is possible to correct the light distribution without any apparent unnaturalness.

Second Embodiment FIG. 12 shows a strobe of the first embodiment in which a reflecting mirror 12 formed of a continuous curved surface is divided in the longitudinal direction and approximated by a plane assembly. Show. By dividing the curved surface, the accuracy of the reflection direction of the reflected light on each surface can be improved. Further, by approximating the curved surface in a stepwise manner, a difference in the height of each surface gives the torsion angle of the strobe, which facilitates design and accuracy.

Third Embodiment FIG. 13 is a cross-sectional view of the reflecting mirror 12 according to the second embodiment, which is further divided in the longitudinal direction, and the curved surface of the reflecting surface is approximated by an aggregate of flat surfaces. In this case, the cross section may be one that can approximate a quadratic curve. In this embodiment, since the reflecting mirror 12 has no curved surface, the accuracy is more easily obtained and the assembling is easier than in the reflecting mirror 12 of the second embodiment.

Fourth Embodiment FIG. 14 shows a strobe in which the light distribution is corrected by inclining the Xe tube 11 without changing the shape of the reflecting mirror 12. In the present embodiment, the light distribution can be corrected with high accuracy when the inclination angle of the strobe with respect to the horizontal plane is small. Therefore, there is an advantage that costs such as processing the shape of the reflecting mirror 12 are not required.

Fifth Embodiment FIG. 15 shows a strobe according to a fourth embodiment in which the shape of the peripheral portion of the reflecting mirror is changed to improve the accuracy of light distribution correction. The light distribution can be approximately corrected near the vertex of the cross section of the reflecting mirror 12 in the fourth embodiment, but the light distribution is disturbed in the peripheral portion. In the present embodiment, the light distribution is appropriately changed by changing only the shape of the peripheral portion of the reflecting mirror 12. The present embodiment has an advantage that it can cope with a large inclination angle of the strobe with respect to the horizontal plane, and is easy to process the reflecting mirror 12 because only the peripheral portion is processed.

[0024]

As described above, according to the camera strobe mechanism of the present invention, the strobe can be arranged at an angle to the horizontal plane of the camera, so that the strobe can be mounted inside the camera body or outside the camera. The range in which the camera can be installed is expanded, and the degree of freedom in camera design can be increased. In addition, since the light distribution to the subject can be properly corrected with a slight loss of light amount, it is extremely practical in terms of the illumination function.

[Brief description of the drawings]

FIG. 1 is a diagram showing a state in which a strobe mechanism according to the present invention is inclined.

FIG. 2 is a schematic sectional view of a strobe mechanism according to the present invention.

FIG. 3 is a ray diagram of a strobe mechanism according to the present invention.

FIG. 4 is a view for explaining a light distribution correcting action of a strobe mechanism arranged in an inclined manner.

FIG. 5 is a diagram for explaining a light distribution correcting action of a strobe mechanism arranged in an inclined manner.

FIG. 6 is a diagram for explaining a light distribution correcting action of a strobe mechanism arranged in an inclined manner.

FIG. 7 is a diagram illustrating a state in which a strobe mechanism is configured by inclining a light emitting member.

FIG. 8A shows a case where the position of the light emitting member is shifted.
(B) is a sectional view of the strobe mechanism when the position of the reflection member is shifted.

9A is a sectional view of a strobe mechanism when a light emitting member is arranged at a focal position of a reflecting member, and FIG. 9B is a cross-sectional view of a strobe mechanism when the position of the light emitting member is shifted.

FIG. 10 is a schematic configuration diagram of a compact camera when a camera strobe mechanism of the present invention is installed in a camera body.

FIG. 11 is an external view of a first embodiment of a camera strobe mechanism of the present invention.

FIG. 12 is an external view of a reflection member according to a second embodiment.

FIG. 13 is a sectional view of a reflecting member according to a third embodiment.

FIG. 14 is an external view of a reflecting member and a light emitting member in a fourth embodiment.

FIG. 15A is an external view of a reflecting member and a light emitting member in the fifth embodiment, and FIG. 15B is a sectional view of the same.

16A is a front view of a conventional camera strobe mechanism, and FIG. 16B is a side view thereof.

FIG. 17 is a diagram for explaining an arrangement position of a strobe mechanism with respect to a camera.

[Explanation of symbols]

 1,11 Xe tube 2,12 Reflector 3,13 Emission window

Claims (2)

(57) [Claims] 1. A light-emitting member, comprising: a reflecting member formed along a longitudinal direction of the light-emitting member and having a substantially concave cross-section, wherein light emitted from the light-emitting member is reflected by the reflecting member; In a camera strobe mechanism configured to irradiate the reflected light to a subject, a longitudinal direction of the light emitting member is provided at an angle with respect to a horizontal plane of the camera, and a concave portion in each cross section of the reflective member is provided. A point sequence in which the vertices of the shape are continuous along the longitudinal direction of the reflecting member, and a finite position of the concave shape in each cross section of the reflecting member.
A non-parallel array of dots formed by making the focal point continuous along the longitudinal direction of the reflecting member, so that the irradiation direction of the reflected light is continuously changed along the longitudinal direction of the reflecting member. An electronic flash mechanism for cameras. 2. A light emitting member, comprising: a reflecting member formed along the longitudinal direction of the light emitting member and having a substantially concave cross section, wherein light emitted from the light emitting member is reflected by the reflecting member; In a camera strobe mechanism configured to irradiate the reflected light to a subject, a longitudinal direction of the light emitting member is provided at an angle with respect to a horizontal plane of the camera, and a light emitting axis of the light emitting member is A focal point at a finite position of the concave shape in each cross section of the reflecting member is provided non-parallel to a point sequence formed by continuing along the longitudinal direction of the reflecting member, and irradiating the reflected light with the longitudinal direction of the reflecting member. A strobe mechanism for a camera, characterized in that the strobe mechanism continuously changes along a direction.