JPS62188101A - Projector with irradiation angle varying mechanism - 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 "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 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.

FIGS. 8 and 9 are cross-sectional views showing the configuration of the source part of this type of flash discharge light emitting device. In these figures, l is the body, 2 is the xenon discharge tube, 3 is the anti-14 tube, 4 is a lens that forms the light emitting window i. In the conventional example shown in FIG. 8, a lens 5 for changing the illumination angle (a lens for telephoto illumination or a lens for wide-angle illumination) is removably provided in front of the illumination window, and in the conventional example shown in FIG. A changing 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. 8, the lens 5 for changing the illumination angle must be attached each time for telephoto shooting or wide-angle shooting, and this lens 5 must be carried. thing,
There are inconveniences such as the possibility of losing the lens 5.

In the conventional example shown in FIG. 9, 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. This makes it difficult to equip a flash discharge light emitting device.

Furthermore, in the conventional examples shown in FIGS. 8 and 9, 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. , the reflecting mirror has a first mirror surface and a second mirror surface having different reflection conditions, and a light source near the light source is configured to restrict the light emission of the light source to either the first mirror surface or the second mirror surface. We propose a light projector equipped with a variable irradiation angle mechanism provided with a light shielding member that selectively projects light.

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 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 cross-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 the side surfaces 12a and 12b of 2 through bushings.

In addition, the reflecting mirror 12 is the upper and lower mirror surfaces of the xenon discharge tube 1),
That is, the upper mirror surface 12c and the lower mirror surface 12 from the base line 13
By changing the curvature of the mirror surface d, the reflection conditions on these mirror surfaces are different. Note that details regarding this point will be described later.

14 is a light shielding plate formed into a long and narrow gutter shape for changing the irradiation angle;
This has an inner surface 14a formed into a mirror surface, and a support shaft 15 is provided at both ends, and this support shaft 15 is connected to the reflecting mirror 1.
Guide holes 12e, 12 bored in side surfaces 12a, 12b of 2
It passes through f and protrudes outside the reflector.

As shown in the figure, the guide holes 12e and 12f are arc-shaped holes that are concentric with the center point of the cross section of the xenon discharge tube 1), and by driving the support shaft 15 along the guide holes 12e and 12f, the light shielding The plate 14 is configured to be displaced above or below the xenon discharge tube 1).

FIGS. 3(a) and 3(b) show the state of irradiated light when the position of the light shielding plate 14 is changed to switch the irradiation angle.

As can be seen from FIG. 3(a), when the light shielding plate 14 is positioned below the xenon discharge tube 1), the light emitted from the xenon discharge tube 1) to the lower mirror surface 12d is blocked, and the upper mirror surface 12
Since the light is projected only in the direction of C, if the upper mirror surface 12c is formed into a parabolic shape and the xenon discharge "IFII" is positioned at the focal point, the reflected light becomes parallel light 16 as shown in the figure.

As shown in FIG. 3(b), when the light shielding plate 14 is moved above the xenon discharge tube 1), the light emitted from the xenon discharge tube 1) is projected only onto the lower mirror surface 12d, and the reflected light is reflected onto the mirror surface 12d.
The light becomes diffused light 17 according to the curvature of d.

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 mirror surface 12C is curved 18, and the lower mirror surface 12d is
FIG. 2 is an explanatory diagram depicting a curve 19. In addition, curve 18
is a parabola with focus at position P1, and curve 19 is at position WIP
The following description assumes that the light source is a parabola having a focal point at P1 and that the light source is at position P1.

When the reflecting mirror 12 is formed into a curved surface as described above, the upper mirror surface 12
The reflection of light from the light source by C becomes parallel light 16, and the reflection of light by lower mirror surface 12d becomes diffused light 17 as shown in the figure.
becomes.

The diffused light 17 has an angle of θ1 with respect to the parallel light 16a generated as reflected light from the lower mirror surface 12d, assuming that the light source is at the position P2. This angle θ1 is the angle θ of O PIQP2, assuming that the reflection part is Q.
Equal to 2.

The irradiation angle θ1 has the characteristics shown in FIG. 5 by changing the X coordinate of the reflecting portion Q.

That is, FIG. 5 is a graph in which the horizontal axis is the X coordinate shown in FIG. 4, the vertical axis is the irradiation angle θ1, and is plotted based on changes in the irradiation angle θl.

As can be seen from this graph, an irradiation angle of 16° can be obtained with the mirror surface 12d having a parabolic cross section according to the conditions shown in FIG. The area of the irradiated light expands.

As can be seen from the above, the light shielding plate 14 is connected to the xenon discharge tube 1).
When it is moved downward and reflected by the upper mirror surface 12C, it becomes parallel light 16, and when the light shielding plate 14 is moved above the xenon discharge tube 1) and reflected by the lower mirror surface 12d, it becomes diffused light 17. By switching and moving the light shielding plate 14 in accordance with standard photography or telephoto photography, standard light emission (diffuse light irradiation) or telephoto light emission (parallel light irradiation) is achieved.

Note that the light shielding plate 14 is switched and moved by driving the spindle 15 through an interlocking mechanism such as a drive lever or a gear, but it is configured to be switched manually. It can be switched and moved in conjunction with movement.

In the above embodiment, the mirror surface 12d that becomes the diffused light 17 is formed on the lower side of the reflecting mirror 12, so that the main optical path of the diffused light 17 is irradiated downward. Mirror surface 12
If the main axis 20 of d is appropriately tilted and the mirror surface 12d is bent from the tentative line 21 shown in the figure to the solid line,
Irradiation can be performed correctly in the front direction of the reflecting mirror 12. Further, if a prism or the like for correcting the diffused light 17 in the front direction is provided at a position in front of the reflecting mirror 12, there is no need to tilt the main shaft 20 as in the above embodiment.

FIG. 7 shows an application example of the present invention using the light shielding plate 14 described above. In this application example, the upper mirror surface 22a and the lower mirror surface 22b of the reflection 1) 22 have the same curvature and have a substantially parabolic cross section, and a lens 23 that can change the irradiation angle is provided in front of the reflection 1) 22. The points are distinctive.

The lens 23 is for wide-angle correction of the light passing through the lower half 23b compared to the upper half 23a, and in this application example,
By switching and moving the light shielding plate 14, effects similar to those of the above embodiment can be obtained. .

In addition to the above-mentioned embodiments, the present invention can be implemented as follows.

(1) The upper mirror surface and the lower mirror surface are formed with the same curvature, and one of the lower and upper mirror surfaces is made of a satin surface.

(2) Contrary to the above embodiment, the upper mirror surface 12c is formed as a reflection surface for the diffused light 17, and the lower mirror surface 12d is formed as a reflection surface for the parallel light 16.

(3) Since the light shielding plate 14 only needs to have a light shielding effect, the inner surface 14a does not necessarily need to be formed into a mirror surface.

(4) In the above embodiments, a reflecting mirror having a substantially parabolic cross section has been described, but a reflecting mirror having an elliptical cross section or a hyperbolic cross section can be similarly implemented.

"Effects of the Invention" As described above, in the present invention, a reflecting mirror having a light source therein is formed with the first & 1) surfaces and the second mirror surface having mutually different reflection conditions, and the light emitted from the light source is directed to the first mirror surface or the second mirror surface. Since a light shielding member is provided to project light onto either side of the mirror,
By switching and driving the light shielding member, the irradiation angle can be easily changed, and the present invention can be satisfactorily implemented 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]

Figures 1 to 6 show examples 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 light emitting part, and Figure 2 is a - A-line enlarged sectional view,
FIGS. 3(a) and 3(b) are simplified diagrams of the light emitting section showing the switching state of the illumination angle, FIGS. 4 and 5 are diagrams for explaining the present invention in detail, and FIG. 6 is a diagram showing the diffused light. FIGS. 7(a) and 7(b) are partial simplified diagrams of an embodiment in which the main optical path direction is corrected; FIGS. 7(a) and 3(b) are similar simplified diagrams showing application examples of the present invention;
Figure 8 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 attached freely, and Figure 9 is a cross-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. It is a top view of a similar light emitting part. 1)...Xenon discharge tube 12...Reflector 12c...Upper mirror surface 12d...Lower mirror surface 12e, 12f...Guide hole 14...Shading plate 14a...Inner surface (mirror surface) 15 ...Spindle. Patent applicant: Stanley Electric Co., Ltd. Figure 1, Figure 2, Figure 6. ) ゝ7V! J (b) F 3 ((1) 1st F Fig. 4 Fig. 3 (b) Ms Fig. 1-X

Claims (3)

[Claims] (1) In a projector in which a light source is fixed in a concave shape of a reflecting mirror having a curved mirror surface, the reflecting mirror is formed with a first mirror surface and a second mirror surface having different reflection conditions, and the light source is A light projector equipped with a variable irradiation angle mechanism provided with a light shielding member nearby that restricts light emission from the light source and selectively projects light onto either the first mirror surface or the second mirror surface. (2) According to claim (1), the light shielding member includes a light shielding plate that partially surrounds the light source and moves around the light source, and the inside of the light shielding plate is formed into a mirror surface. A floodlight equipped with the variable irradiation angle mechanism described above. (3) A xenon discharge tube is fixed to the deep part of a reflector with an almost parabolic cross section, and the curvature of the mirror surface on one side and the mirror surface on the other side of the reflector parallel to the xenon discharge tube is changed to provide mutual reflection conditions. A gutter-shaped light-shielding plate having a first mirror surface and a second mirror surface having different values and having a mirror surface on the inside was provided so as to be rotatable around the xenon discharge tube, and was implemented as a light emitting part of a flash discharge light emitting device for photography. A projector equipped with a variable irradiation angle mechanism according to claim (1).