JPH05341359A - Stroboscopic device - Google Patents

Abstract

PURPOSE:To provide a stroboscopic device where the loss of light caused by internal reflection in a protective panel is little and especially a light quantity at the peripheral part of a light distribution angle is prevented from lowering. CONSTITUTION:This device is equipped with a bar-like flash discharge tube 1 for emitting light, a reflector 2 which is disposed around the flash discharge tube, whose front surface is opened, whose internal reflection surface has a longitudinal section formed to be an umbrella-shaped curved surface, and which reflects the emitted light from the flash discharge tube 1 forward, and the protective panel 3 which is disposed to be opposed on the aperture side of the reflector 2, and formed so that at least the peripheral part opposed to both side parts of the flash discharge tube 1 is formed to have an optical concave shape such as a curved surface, an inclined surface, and a stair-like surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strobe device, and more particularly to a protective panel in a light emitting portion of a strobe device for photography.

[0002]

2. Description of the Related Art As is well known, as shown in FIG. 6, a light emitting portion of a strobe device for photography is provided with a rod-shaped straight tube type flash discharge tube 11 and a discharge tube 11 which covers the discharge tube 11. It is composed of a reflector 12 made of a reflective shade having an opening on the front surface, and a protective panel 13 made of a diffuser plate arranged so as to face the opening of the reflector 12.

The flash discharge tube 11 is composed of a so-called xenon flash discharge lamp in which xenon gas is filled, and a high voltage is applied to the opposing anode 11a and cathode 11b, and a high voltage is applied to its trigger electrode. Flash light emission is performed by applying a trigger pulse voltage. Further, the reflector 12 is formed in a horizontally long gutter shape whose longitudinal cross-sectional shape is an elliptical shape with an open front surface, and the inner surface thereof is aluminum-plated, and the flash discharge tube 11 is located near the focal point of the ellipse. Are mounted so that they are positioned. Therefore, when the flash discharge tube 11 emits light, the light is reflected on the inner surface and is radiated forward from the front opening 12a.

A protective panel 13, which is called a protector and is made of a transparent diffusion plate made of synthetic resin or the like, is disposed so as to face the front opening 12a of the reflector 12. The protection panel 13 emits diffusive irradiation light, protects the flash discharge tube 11 and the reflector 12,
It plays a role of preventing electric shock, controlling light distribution, and the like, and the inside thereof is generally formed as a flat surface or a convex Fresnel lens.

[0005]

By the way, although the conventional protective panel having such a structure is formed transparently, as shown in FIG. 6, among the light emitted from the flash discharge tube 11, as shown in FIG. , A part of the light incident at a low angle is reflected. For example, when the light L emitted from the vicinity of the anode 11a of the flash discharge tube 11 is incident on the peripheral portion of the protection panel 13 facing the cathode 11b of the flash discharge tube 11 at a low angle, a part of the La is an inner surface. It is reflected at and does not go out. This means that the anode 1 of the flash discharge tube 11 is
The same applies to the peripheral portion of the protection panel 13 that faces 1a. Therefore, in the conventional strobe device for photography, there is a drawback in that the irradiation efficiency is reduced due to the internal reflection in the peripheral portion of the protection panel 13, and the light amount particularly in the peripheral portion of the light distribution angle is significantly reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a strobe device which has a small loss of light due to internal reflection in a protective panel and which can prevent a decrease in the amount of light particularly in the peripheral portion of a light distribution angle.

[0007]

A strobe device according to the present invention comprises a rod-shaped flash discharge tube for light emission, and a flash discharge tube for light emission, which is arranged around the flash discharge tube and has a front surface opened and a vertical cross section of a reflection surface on an inner surface. A reflector which is formed in a curved shape of a bulk shape and which reflects the light emitted from the flash discharge tube toward the front, and an opening of the reflector which is arranged so as to oppose the crocodile, and at least both sides of the flash discharge tube. The protective panel is provided with a peripheral part facing the part and having an optical concave surface shape such as a curved surface, an inclined surface, or a stepped surface.

[0008]

[Function] Since the peripheral portion of the protective panel facing both sides of the flash discharge tube is formed into an optically concave surface such as a curved surface, an inclined surface, or a stepped surface, the incident angle to this portion is increased, and the inner surface is increased. Less reflection.

[0009]

The present invention will be described below with reference to the illustrated embodiments. FIG. 1 shows a first embodiment of the present invention and is a plan view of a light emitting portion of a strobe device for photography.
The structure and operation of the flash discharge tube and the reflector in the first embodiment and the embodiments described below are as shown in FIG.
Since it is the same as the light emitting portion of the conventional strobe device described above, detailed description thereof will be omitted.

As shown in FIG. 1, a rod-shaped straight tube type flash discharge tube 1 having an anode 1a, a cathode 1b and a trigger electrode (not shown) facing each other is a front opening 2a for emitting light emission.
Is covered with a horizontally long gutter-shaped reflector 2 having an elliptical vertical cross-section, and the light emitted by the inner reflection surface of the reflector 2 is directed forward. Then, the protection panel 3 to which the present invention is applied is disposed so as to face the front opening 2a. The protective panel 3 is formed by forming a transparent plate made of synthetic resin or the like in an outer surface and an inner surface in a meniscus shape.

In the light emitting portion of the stroboscopic device having the protection panel 3 thus constructed, the anode 1a of the flash discharge tube 1 and the peripheral portion of the protection panel 3 facing both sides of the flash discharge tube 1 are provided. The light L emitted from the vicinity of the cathode 1b enters at a high angle. That is, since the incident angle of the light ray on the peripheral portion of the protection panel 3 becomes high, the internal reflection at this portion can be reduced. As for the relationship between the incident light and the reflected light, as shown in the definition of “angle of incident light” in FIG. 7, in the present invention, the angle θ with the normal being 90 degrees is the incident angle.

FIG. 2 shows a second embodiment of the present invention. The protective panel 3A in the second embodiment is formed by the inclined surfaces 3Aa and 3Ab facing the both sides of the flash discharge tube 1, the peripheral portion of the protective panel 3A being rearward, that is, the reflector 2 being inclined toward the arm. Has been done.

According to the light emitting portion of the strobe device having the protection panel 3A constructed as described above, the light is emitted from both ends of the flash discharge tube 1 which are incident on the inclined surfaces 3Aa and 3Ab in the peripheral portion of the protection panel 3A. Since the incident angle of the incident light is large, the internal reflection is small. In other words, most of the inner surface reflection is in the peripheral portion facing both sides of the flash discharge tube 1,
By forming this portion on the inclined surface, the same effect as that of the first embodiment can be obtained. FIG. 3 shows a third embodiment of the present invention. Protective panel 3 in this third embodiment
B is similar to the protection panel 3A of the second embodiment, in that the peripheral portion of the protection panel 3B is formed with inclined surfaces 3Ba and 3Bb that are inclined toward the reflector 2 and the Fresnel lens 3Bc is formed on the outer surface thereof. I am doing it. As is well known, the Fresnel lens has a condensing effect toward the peripheral portion. Therefore, a bright illumination light can be obtained even in the peripheral portion of the photographing screen by a synergistic effect with the effect of reducing the internal reflection due to the inclined surface or the meniscus in the peripheral portion of the protective panel.

FIG. 4 shows a fourth embodiment of the present invention. The protection panel 3C in the fourth embodiment is obtained by forming the protection panel 3 in the first embodiment into a meniscus convex lens. When formed in this way, there is no step as in the Fresnel lens of the third embodiment, so there is the effect that the loss of light quantity is small.

FIG. 5 shows a fifth embodiment of the present invention. In this fifth embodiment, the protection panel 3D is
The central portion is a parallel diffuser plate, and the peripheral portions facing both sides of the flash discharge tube 1 are formed as stepped surfaces 3Da and 3Db. When the protective panel 3D is formed in this manner, the second
In addition to the same effect as the protective panel 3A of the embodiment, the entire stroboscopic light emitting portion can be made thin.

[0016]

As described above, according to the present invention, the shape of the peripheral portion of the protective panel facing both sides of the flash discharge tube is formed into an optically concave surface such as a curved surface, an inclined surface, or a stepped surface. Therefore, the incident angle to this portion is increased, the internal reflection is reduced, and therefore, it is possible to prevent the decrease in the light amount in the peripheral portion of the light distribution angle, and to eliminate the drawbacks of the conventional strobe device of this kind, and to improve the irradiation efficiency. A good photographic strobe device can be provided.

[Brief description of drawings]

FIG. 1 is a plan view of a light emitting portion of a flash device showing a first embodiment of the present invention.

FIG. 2 is a plan view of a light emitting portion of a flash device showing a second embodiment of the present invention.

FIG. 3 is a plan view of a light emitting portion of a flash device showing a third embodiment of the present invention.

FIG. 4 is a plan view of a light emitting portion of a flash device showing a fourth embodiment of the present invention.

FIG. 5 is a plan view of a light emitting portion of a flash device showing a fifth embodiment of the present invention.

FIG. 6 is a plan view showing an example of a light emitting unit of a conventional strobe device.

FIG. 7 is a diagram showing a relationship between angles of incident light.

[Explanation of symbols]

 1 …………………………………………… Flashlight discharge tube 2 ……………………………………… Reflector 2a ……………………………………… …… Aperture 3,3A, 3B, 3C, 3D ………… Protection panel

Claims (1)

[Claims] 1. A rod-shaped flash discharge tube for light emission, and a flash discharge tube arranged around the flash discharge tube, the front surface of which is open, and the reflection surface of the inner surface is formed into a curved curved surface in the shape of a sphere. A reflector for reflecting the light emitted from the flash discharge tube toward the front, and an opening of the reflector facing the crocodile,
A strobe device, comprising: a protection panel in which at least peripheral portions facing both sides of the flash discharge tube are formed in an optically concave surface shape such as a curved surface, a sloped surface, or a stepped surface.