JPS62296132A - Projector - Google Patents

Abstract

PURPOSE:To easily change the projecting angle of a light projector, by providing a light source in such a state that the position of the light source can be displaced in the forward-backward direction against an reflecting mirror. CONSTITUTION:The reflecting mirror 10 of this projector is composed of a main reflecting mirror 11 fixed to the main body of this projector and an auxiliary reflecting mirror 12 which can be slid in the forward-backward direction. The auxiliary reflecting mirror 12 is fitted with a xenon discharge tube 14 acting as a light source, with the discharge tune 14 being slidable in the forward-backward direction by means of a sliding member 15 in the rear. When the xenon discharge tube 14 is placed between a focal point and the apex of the parabola formed by the mirror 10, reflected rays of light are scattered and, when the light source 14 is placed between them nearer to the opened side of the parabola than the focal point, the reflected rays of light are condensed. Therefore, when a driving rod 20 is moved in the directions A and B, the position of the light source can be moved and the projecting angle can be changed suitably for standard and telescopic photographings. Thus the projecting angle can be changed easily with a simple structure.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention "Field of Industrial Application" The present invention relates to various types of floodlights, for example, a floodlight used as a light emitting part of a flash discharge light emitting device for photography.

``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 in the front 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 depending on telephoto shooting or T-angle shooting. There is a structure in which a lens for use is provided in front of the light emitting window.

6 and 7 are cross-sectional views showing the structure of the light emitting part of this type of flash discharge light emitting device. In these figures, 1 is a body, 2 is a xenon discharge tube, 3 is a reflector, and 4 is a This is a lens that forms a light emitting window.

In the conventional example shown in FIG. 6, the illumination angle changing lens 5 (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 for changing the illumination angle is slidably provided on the Pod 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. 7, 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, but since this lens 6 has a zoom structure, it is small. This makes it difficult to equip a flash discharge light emitting device.

Furthermore, in the conventional examples shown in FIGS. 6 and 7, the lenses (5, 6) for changing the illumination angle 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 placed within the concave shape of a curved reflecting mirror, and the position of the light source is reflected. We propose a floodlight characterized by a structure in which the irradiation angle is switched by displacing the mirror in the front-rear direction.

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. You can switch the illumination angle to suit telephoto 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.

A first embodiment is shown in FIGS. 1 to 3.

FIG. 1 is a perspective view of the rear of the light emitting section, and the reflecting mirror 10 has a curved surface having a substantially parabolic cross section. This reflecting mirror 10 is divided into two by a plane perpendicular to the symmetry axis of the parabola, and the open side of the reflecting mirror 10 is used as the main reflecting mirror 11, and the closed side (back bank side)
is used as the sub-reflector 12.

The main reflecting mirror 11 is fixed to the main body 13 of the flash discharge light emitter, and the sub-reflecting mirror 12 has a xenon discharge tube 14 fixed thereto as a light source so as to lie in the longitudinal direction of the reflecting mirror 10.

A sliding member 15 is provided behind the sub-reflector 12 so as to be slidable in the direction of the symmetry axis of the reflector 10 with respect to the main body 13.
is the provision. This sliding member 15 is formed into a substantially 5-shaped cross section as shown in the figure, and has elongated holes 16 and 16 in the horizontal portion 15a.
A pin 17.17 implanted in the main body 13 is loosely inserted into the elongated hole 16.16 to guide sliding movement. In addition, the vertical portion 1 of the sliding member 15
A rod 18.18 projecting laterally is installed in 5b, and the opening 18.18 is engaged with a bracket 19.19 projecting rearward from the rear of the sub-reflector 12. Further, reference numeral 20 in FIG. 1 denotes a drive rod that can be operated and driven directly from the outside of the main body 13 or via an operating phase, and is rotatably supported on the main body 13 by a pin 21. In the case of a flash discharge light emitting device built into the camera, the drive rod 20 is linked to the switching mechanism of the photographic lens so that it is driven in accordance with telephoto shooting or wide-angle shooting.

A long hole 22 is formed at the upper end of the drive rod 20, and a pin 23 installed in the horizontal portion 15a of the sliding member 15 is loosely inserted into the long hole 22.

Note that a lens 24 is provided in the open portion of the main reflecting mirror 11.

Next, the operation of the projector according to the present invention will be explained with reference to FIGS. 2 and 3.

Assuming that the reflecting mirror 10 is formed into a curved surface with a parabolic cross section, this reflecting mirror 10 will follow a curve expressed by y=4px. Here P is the focal point. When the xenon discharge tube 14 is placed at point P, the light rays emitted from the xenon discharge tube 14 are reflected by the inner surface of the main reflecting mirror 11 and become parallel rays due to the characteristics of a parabola.

When the xenon discharge tube 14 is placed between the focal point and the apex of the parabola, the reflected light beam is diffused, and when it is placed on the open side of the parabola rather than the focal point, it is condensed. When condensing light, the point of convergence becomes farther as the light source is closer to the focal point and closer as the light source is farther from the focal point.

As shown in FIG. 2, when the xenon discharge tube 14 is placed near the focal point, the reflected light rays converge at a far distance, and the far distance is well irradiated. On the other hand, as shown in FIG. 3, when the xenon discharge tube 14 is placed at a position away from the focal point, the reflected light rays converge nearby and then proceed straight to irradiate a wide range of short distances.

That is, the state shown in FIG. 2 is suitable for telephoto shooting, and the state shown in FIG. 3 is suitable for standard shooting.

When the camera is switched to the standard photographing position and the drive rod 20 is operated, the upper end of the drive rod 20 pivots about the pin 21 in the direction of the upper arrow A in FIG.

This rotation of the upper end of the drive rod 20 causes the sliding member 15 to slide via the pin 23 in the direction of the upward arrow Q in FIG. The sliding of the sliding member 15 causes the sub-reflector 12 and the xenon discharge tube 14 to move in the same direction, changing the position shown in FIG. 2 to the position shown in FIG. 3 to emit a flash suitable for standard photography. Be able to do things.

When the photographing lens is switched from the standard photographing position to the telephoto photographing position and the drive rod 2o is operated in the opposite direction to that described above, the upper end of the drive loft 20 turns in the direction of arrow B in FIG. The sub-reflector 12 and the xenon discharge tube 14 are slid in the direction opposite to the arrow Q in the figure to the position where they emit flash light for telephoto photography as shown in FIG.

Next, the embodiment shown in FIG. 4 will be described.

The xenon discharge tube 14 lies deep inside the reflecting mirror 10 and is movable relative to the reflecting mirror 10 along the axis of symmetry of the parabola of the reflecting mirror 1o. The xenon discharge tube 14 is fixed to a bracket 25.25, and this bracket 25.25 is attached to a sliding member 15 provided at the rear of the reflecting mirror 10.

The reflecting mirror 10 in this embodiment is not divided into two parts unlike the embodiment shown in FIG.
A long hole (not shown) in the direction of the symmetry axis of the parabola is formed in 26, and the xenon discharge tube 14 is loosely inserted into this long hole. Note that the drive rod 20 can also be configured to be rotatable in a horizontal plane about a pin 21 implanted in the main body as shown by the dashed line in FIG. A vertically protruding pin 23 is loosely inserted into the sliding member 15. Note that this point also applies to the embodiment shown in FIG.

Next, FIG. 5 shows an example of the light emitting part of a flash discharge light emitting device built into a camera.

Reference numeral 27 in FIG. 5 is a lens drive motor, and the photographic lens is switched between telephoto photography and standard photography from a drive gear 29 fitted on the output shaft 28 of this lens drive motor 27 via a transmission gear 30. .

The rotation of the drive gear 29 is transmitted via an idle gear 31 to a driven gear 33 rotatably supported on the side plates 32, 32 of the reflecting mirror 10.

The xenon discharge tube 14 is attached to a position offset from the center of rotation of the driven gear 33, and the xenon discharge tube 14 turns as the driven gear 33 rotates.

In addition, a through hole (not shown) of sufficient size to allow the xenon discharge tube 14 to rotate is formed in the side plates 32, 32 of the reflecting mirror 1o. In FIG. 5, reference numeral 34 denotes a rotating member, which is rotatably supported on the camera body so as to support one end of the xenon discharge tube 14.

In the embodiment shown in FIG. 5, when the lens driving motor 27 switches between the telephoto shooting position and the standard shooting position of the taking lens, the driven gear 33 rotates through the idle gear 31 in the driving gear 29, and the xenon discharge By pivoting the tube 14, this xenon discharge tube 14 is displaced to two different positions on the axis of symmetry of the parabola of the reflector 10.

In the embodiments described above, switching between the telephoto shooting flash and the standard shooting flash was explained, but it is also possible to displace the xenon discharge tube 14 so as to switch between the telephoto shooting flash and the standard shooting flash. , a configuration may be adopted in which the xenon discharge tube 14 is displaced so as to switch to three stages of wide-angle shooting light emission.

Further, although the present invention has been described with reference to the light emitting section of a flash discharge light emitting device, it can be similarly applied to a floodlight such as a searchlight.

"Effects of the Invention" As described above, in the present invention, the position of the light source can be displaced with respect to the reflecting mirror, so the irradiation angle can be easily changed by moving the position of the light source. Additionally, there is no need for external components such as lenses for changing the illumination angle, which eliminates the hassle of carrying them around.Since the illumination angle switching mechanism has a simple structure, it can be easily applied to small floodlights. can. In particular, it can be implemented as a light emitting part of a flash discharge light emitting device built into a camera, which is advantageous because the irradiation area can be easily switched depending on telephoto shooting or wide-angle shooting.

[Brief explanation of the drawing]

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. Figure 1 is a perspective view of the rear of the light emitting unit, Figures 2 and 3 are cross-sectional views taken along line A-A in Figure 1, and Figure 2 is a perspective view of the rear of the light emitting unit.
The figure shows diffused light photography. Fig. 4 is a rear perspective view of the light emitting part showing another embodiment;
The figure is a rear perspective view of the light emitting part showing an embodiment using a gear mechanism, and FIG. 6 is a sectional view showing the light emitting part of a conventional flash discharge light emitting device equipped with a lens for changing the irradiation angle that can be freely attached. 7th
This figure is a top view of a light emitting part similar to that shown in FIG. 6, which is equipped with a slidable lens for changing the irradiation angle. 10...Reflector 11...Main reflector 12.
・・Sub-reflector 14・Xenon discharge tube 15・
...Sliding member 20...Drive port 7 door 27...
Lens drive motor 33...driven gear. Figure 4 115132+

Claims (3)

[Claims] (1) A light projector characterized in that a light source is disposed within a concave shape of a curved reflecting mirror, and the illumination angle is switched by displacing the position of the light source in the front-rear direction of the reflecting mirror. (2) The back bank of the reflector is formed as a sub-reflector, and the other parts are formed separately as the main reflector, and a light source is provided on the sub-reflector, and both the light source and the sub-reflector are displaced. A projector according to claim (1). (3) Rotating bodies are provided on both sides of a reflecting mirror with an approximately parabolic cross section, and both sides of the xenon discharge tube are supported at positions offset from the center of rotation of these rotating bodies, so that the position of the xenon discharge tube inside the reflecting mirror is rotated as described above. The projector according to claim (1), which is configured to be displaced according to the rotational position of the body and is implemented as a light emitting part of a flash discharge light emitting device.