JPS62180901A - Projector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION □ "□ Industrial Application Field" □ The present invention relates to various types of floodlights, for example, a floodlight that is used as a light emitting part of a flash discharge light emitting device for photography.

1. Prior Art A flash discharge light emitting device used for photography is configured to emit light from a xenon discharge tube through a light emitting window provided on the front surface of the flash discharge light emitting device.

In such a light emitter, the irradiation angle is kept constant by a reflector with an almost parabolic cross section that has a xenon discharge tube fixed inside, but the irradiation angle is changed according to telephoto shooting or wide-angle shooting, so it is necessary to change the irradiation angle. There is a structure in which a lens is provided in front of a light emitting window.

9 and 10 are cross-sectional views showing the structure of the light emitting part of this type of flash discharge light emitting device, and in these figures, 1
2 is a body, 2 is a xenon discharge tube, 3 is a reflecting mirror, and 4 is a lens forming a light emitting window.

In the conventional example shown in FIG. 9, a lens 5 for changing the irradiation angle (telephoto irradiation lens or wide-angle irradiation lens) is removably provided in front of the light emitting window, and in the conventional example shown in FIG. A lens 6 is slidably provided on the body 1 so as to move forward and backward in front of the light emitting window.

"Problems to be Solved by the Invention" In the case of the conventional example shown in FIG. There is the inconvenience of having to carry it with you.

In the conventional example shown in FIG. 10, the lens 6 for changing the illumination angle can be moved forward or backward according to telephoto shooting or wide-angle shooting, and there is no inconvenience as described above. However, since this lens 6 has a zoom structure, it is small and This makes it difficult to equip a flash discharge light emitting device.

Furthermore, in the conventional examples shown in FIGS. 9 and 10, the irradiation angle changing lenses (5, 6) cannot be used for interchangeable lenses of compact cameras.

"Means for Solving the Problems" The present invention was developed with the aim of solving the above-mentioned problems.A light source is fixed within the concave shape of a main reflecting mirror having a curved surface, and the main reflection for this light source is A projector is proposed in which a sub-reflector having mirror surfaces with different reflection conditions is provided on the outside of the mirror, and the sub-reflector is rotated to change the reflection angle conditions.

Currently, small cameras have been developed that have a built-in flash discharge light emitting device and can switch the photographing lens to telephoto shooting or wide-angle shooting. The illumination angle can be switched for telephoto shooting or wide-angle shooting.

Note that the present invention is not limited to being applied to the light emitting part of a flash discharge light emitting device, but is effective when being applied to various types of floodlights.

``Example'' Next, examples in which the present invention is implemented as a light emitting part of a flash discharge light emitting device will be described with reference to the drawings.

Figure 1 is a perspective view of the light emitting section, and Figure 2 is A-A in Figure 1.
FIG. 3 is an enlarged sectional view taken along line A.

In these figures, 1) is a xenon discharge tube, and 12 is a reflecting mirror. It is fixed to 12a and 12b via bushings.

Reference numeral 13 denotes a movable reflecting mirror for changing the irradiation angle, which is made of an elongated plate shape, and its negative surface 13a is a flat mirror surface, and the other surface 13b is
The curved mirror surface or G\ which is bulged out is formed on the pear-skinned surface, and a support shaft 14 is provided at both ends, and this support shaft 1
4 is rotatably inserted into the side surfaces 12a and 12b of the reflecting mirror 12, thereby allowing the movable reflecting mirror 13 to be rotatably mounted.

By rotating the support shaft 14, the movable reflecting mirror 13 can be moved to a position where the negative surface 13a directly faces the xenon discharge tube 1) and the other surface 13b as shown in FIGS. 3(a) and 3(b). The structure is such that the position can be switched to a position directly facing the position.

As shown in FIG. 3(a), when one surface 13a of the movable reflector 13 directly faces the xenon discharge tube 1),
The xenon discharge tube 1) is connected to the bottom surface of the reflector 12 so that the light emitted from the xenon discharge tube 1), which is primarily reflected by the movable reflection tJi13 and secondarily reflected by the reflector 12, is irradiated as parallel light 15. The distance and the position of the movable reflector 13 are set.

With this configuration, by switching the movable reflecting mirror 13 as shown in FIG. 3(b), this reflecting mirror 13
The light emitted from the xenon discharge tube 1) is emitted as diffused light 16 by the primary reflection by the reflector 12 and the secondary reflection by the reflecting mirror 12.

Next, the principle of the present invention will be optically explained using FIGS. 4 and 5.

FIG. 4 assumes that the reflecting mirror 12 is formed as a parabolic cross section, and the upper half is drawn as a curved line 17.
If this curve 17 is focused at point P, then y=4px.

In this figure, when the light source is placed at point P, the reflective surface (curve 1
The light reflected by 7) becomes parallel light 15.

When the light source is moved to the right side (O side) from point P, the light is diffused as shown by the dotted line in the diagram, and conversely, when the light source is moved from point P to the left side (+ side), the light is diffused. If you change it to , the light will be focused.

The present invention changes the irradiation area based on the above-mentioned optical principle, and is characterized by the use of a movable reflecting mirror instead of moving the light source.

FIG. 5 is an explanatory diagram showing the reflection state of the movable reflecting mirror 13 shown in the above embodiment, where point A is the center point of the curve corresponding to the other surface 13b, point D is the light m4f position, and point B is It is a mirror image point with the straight line 19 corresponding to the surface 13a as the base line. The 0 point is a mirror image point of the other surface 13b (curve 18), and as understood from geometric optics, the coordinate point is (1/ a ) + (1/
b) From -(2/R), it becomes -(6/7).

Here, if point B is at the same position as point P in Figure 3, using the - plane 13a (straight line 19), it will be the same as if the light source were placed at point P in Figure 4, and it would be parallel. Becomes light.

Also, when the other surface 13b (curve 18) is used, it is the same as if the light source were placed at the 0 point in FIG.
In the figure, this is equivalent to moving the light source to the right side (0 side) from point P, and the light becomes diffused by utilizing the reflection from the other surface 13b.

As can be seen from the above, by directly facing the surface 13a of the movable reflector 13 to the xenon discharge tube 1), the parallel light 1)
5, and if the other surface 13b is switched to face directly, it becomes diffused light 16. Therefore, by rotating the movable reflector 13 in accordance with standard photography or telephoto photography, standard light emission (diffuse light irradiation or Telephoto emission (parallel light irradiation).

The movable reflector 13 is rotatably driven by rotating a support shaft 14 through an interlocking mechanism such as a drive lever or a gear, but in addition to being rotatably driven manually, in the case of a camera with a built-in flash discharge light emitting device, the photographing lens is rotated. It can be rotated in conjunction with movement.

Further, when carrying out the present invention, it is preferable to form a curved surface portion 12c centered on the xenon discharge tube 1) on the bottom surface of the reflecting mirror 12, as shown in FIG.

By forming this curved surface portion 12C in accordance with the viewing angle θ of the movable reflecting mirror 13, the influence of switching of the movable reflecting mirror 13 on the light directly directed from the xenon discharge tube 1) to the curved surface portion 12c is reduced. , the effect of switching the irradiation area can be increased.

FIG. 7 shows another embodiment of the present invention in which the movable reflecting mirror 2o is formed of a long curved plate, and both the front and back surfaces are mirror-finished.
It is configured to rotate as shown in a) and (b). In this embodiment, the irradiation area can be switched in the same manner as in the above embodiment by appropriately setting the curved surface of the reflecting mirror 1, its position, the distance between the xenon discharge tube 1) and the bottom surface of the reflecting mirror 12, etc. I can do it.

Figure 8 shows three surfaces 21a, 21b, and 21c with different reflection conditions.
A movable reflecting mirror 21 having a mirror surface is shown. This movable reflecting mirror 21 is rotatably mounted within the reflecting mirror 12 in the same manner as described above, and configured so that each of the mirror surfaces 21a, 21b, and 21c directly faces the xenon discharge tube 1).

According to this embodiment, the mirror surface 21a is the xenon discharge tube 1)
By directly facing the
The irradiation area can be switched in one of three stages, such that wide-angle irradiation using diffused light is achieved when the mirror surfaces 21b are directly opposed, and telephoto irradiation is achieved using condensed light when the mirror surfaces 21c are directly opposed.

As mentioned above, in the present invention, since the sub-reflector having mirrors/surfaces with different reflection conditions is rotatably provided within the main reflector 1), it is possible to rotate the sub-reflector. The illumination angle can be easily changed by using this method, and it can also be implemented satisfactorily even with a small projector.

In particular, it can be implemented as a light emitting part of a flash discharge light emitting device built into a camera, and is advantageous in that the irradiation area can be switched depending on telephoto shooting or wide-angle shooting.

[Brief explanation of drawings]

The drawings show an example in which the present invention is implemented as a light emitting part of a flash discharge light emitting device used for photography. Fig. 1 is a perspective view of the light emitting part, and Fig. 2 is an enlarged cross-sectional view taken along line A-A in Fig. 1. , Figure 3 (a
), (b) are simplified partial enlarged views of the light emitting section showing the switching state of the irradiation area, FIGS. 4 and 5 are views for explaining the present invention in detail, and FIG. 6 is the inner bottom surface of the reflecting mirror. A simplified partially enlarged view showing the shape, FIGS. 7(a) and 7(b) are simplified views of a light emitting part showing another embodiment, and FIG. 8 is a cross-sectional view of a movable reflecting mirror having three mirror surfaces with different reflection conditions. , FIG. 9 is a sectional view showing the light emitting part of a conventional flash discharge light emitting device equipped with a lens for changing the illumination angle that can be freely attached, and FIG. It is a top view of a light emitting part similar to the figure. 1)...Xenon discharge tube 12...Reflector 13.
...Movable reflecting mirror 13a...-surface (mirror surface) 13
b...Other surface (mirror surface) 14...Spindle 20.21
...Movable reflecting mirrors 21a, 21b'-21c"' mirror surfaces. Patent applicant: Stanley Electric Co., Ltd. Figure F, Figure 2, Figure 3 (Q) c b), Figure 4
Figure 9

Claims (2)

[Claims] (1) A light source is fixed within the concave shape of the main reflecting mirror with a curved surface,
A projector having a configuration in which a sub-reflector having a mirror surface with different reflection conditions is provided outside the main reflector with respect to the light source, and the sub-reflector is rotated to change the reflection angle condition. (2) A xenon discharge tube is fixed at the back of a reflector with an almost parabolic cross section, and a movable reflector with different reflection angle conditions on the front and back sides can be freely rotated near the opening of the reflector relative to the xenon discharge tube. A floodlight according to claim (1), which is provided in a camera and is implemented as a light-emitting part of a flash discharge light-emitting device for photography.