JPH10177199A - Strobe device for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera strobe device capable of obtaining a more efficient luminance intensity distribution characteristic without enlarging the external size of a pop-up type strobe device and that of a camera loading the strobe device on it. SOLUTION: The strobe device is provided with a reflector 2 forming the cross-sectional shape in its minor side direction as an approximate ellipse or its approximate curved surface shape and forming a counter end face in the minor side direction by reflection face extended by mutually parallel plane reflection boards 2b, a straight type light emitting flash discharge tube 1a arranged along the major side direction in the vicinity of the focal position of the approximate ellipse or approximate curved surface in the reflector 2 and both the sidewall parts of the reflector 2 arranged in the vicinity of both the end parts of the discharge tube 1a, extended up to the vicinity of the tip of the reflector and capable of reflecting major side direction light from the discharge tube 1a and the approximately center part of the couter tip part of the reflection board 2b is formed like a circular arc along the outer periphery of a photographing lens-barrel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strobe device for a camera, and more particularly, to a strobe device for a pop-up camera which is housed in a photographic lens barrel with a front side of a light-emitting portion being substantially downward. The present invention relates to a strobe device of a camera for irradiating a light beam emitted from a light-emitting flash discharge tube toward a subject by a reflector in use.

[0002]

2. Description of the Related Art Conventionally, a strobe device as an auxiliary light source has been widely used, for example, when an environment for taking a photograph is in a low illuminance environment. This strobe device irradiates a light beam emitted from a straight tube type flashlight discharge tube to a subject by a reflector (hereinafter, referred to as a reflector).

[0003] In the reflector of such a strobe device, the cross-sectional shape (longitudinal cross-sectional shape) in the short side direction is generally formed into a substantially elliptical opening having a front surface or a curved surface shape similar thereto. This is a shape that can control the light distribution most efficiently when irradiating the luminous flux from the luminous flash discharge tube into a predetermined area (within a predetermined angle of view).

In other words, by adopting such a shape, the angle formed by two lines connecting the opposite ends of the reflector in the short side direction and the central axis of the flash tube for light emission can be determined by the photographing lens. If the angle of view is set to be substantially the same as or slightly larger than the angle of view, a desired irradiation angle can be set corresponding to the angle of view of the taking lens.

However, in the above-described strobe device, since the size in the long side direction is longer than the size in the depth direction of the reflector, in the long side direction, there are many useless light rays that go out of the angle of view. There are drawbacks.

Therefore, as means for preventing this, a proposal described in, for example, Japanese Patent Application Laid-Open No. 5-341358 has been made.

In the strobe device disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 5-341358, both side walls of a reflector for reflecting a light beam irradiated in the long side direction of the flashlight discharge tube for light emission are formed into a substantially elliptical or approximate curved shape. Is formed so that the luminous flux from the flashlight discharge tube for light emission falls within the angle of view, and furthermore, the opposite end surfaces in the short side direction of the reflector are parallel to each other with a plane reflecting plate. It is formed by a reflective surface extended by.

[0008] According to this, the useless light rays that escape to the outside of the angle of view in the long side direction of the reflector are reflected on both side walls and guided into the angle of view, thereby minimizing the useless rays of light and improving the quality. Light distribution can be obtained.

On the other hand, in recent years, a small camera using a roll film having a width of 35 mm, which incorporates a strobe device in the camera body, has been put to practical use. In such a camera, the strobe device is used by popping up as necessary at the time of photographing, while the strobe device is stored in the camera body when carrying the camera.

[0010] In such a pop-up type flash device, the storage form in the camera body is as follows.
With the light-emitting unit being housed facing the photographing lens barrel, the front opening window of the light-emitting unit is substantially downward, that is, the front opening window of the light-emitting unit is part of the outer peripheral surface of the photographing lens barrel. The one that is stored in a state facing the above is generally put into practical use.

[0011]

However, in the means disclosed in Japanese Patent Application Laid-Open No. 5-341358, since the length of the reflector in the depth direction is increased, the size of the apparatus itself is increased. There is a problem, so
The camera equipped with this strobe device also becomes large. In particular, when the light emitting unit is housed on the taking lens barrel and the light emitting window on the front is housed substantially downward, the longer the length of the reflector in the depth direction, the higher the height of the camera itself. The external dimensions become high.

FIGS. 7 and 8 show the above-mentioned Japanese Patent Application Laid-Open No. 5-34135.
8A and 8B are a plan view and a side sectional view schematically showing a strobe device disclosed in Japanese Patent Application Publication No. 8; Here, the influence of the side wall of the reflector on the light distribution characteristics in the short side direction will be described with reference to FIGS.

In FIGS. 7 and 8, the trajectory of the light beam indicated by the reference numeral 105b is a light beam emitted from an arbitrary point A substantially in the center of the straight tube type flashlight discharge tube 101 to the front of the reflector 102, and Among the light rays emitted on the plane orthogonal to the light emitting flash discharge tube 101, the light rays reflected at the point B1 on the reflector 102b facing in the short side direction of the reflector 102 are shown. The trajectory indicates a light ray from the point A, which is reflected at the point B2 on the reflector 102b, and further reflected and emitted at a point C on the side wall 102c.

As described above, when both side walls 102c of the reflector 102 are formed to be longer than the length in the depth direction of the substantially elliptical or approximate curved surface shape, as shown in FIG. In the side direction, both rays 10
Both 5a and 105b are irradiated within the angle of view.

On the other hand, in the short side direction of the reflector 102,
As shown in FIG. 8, the light ray 105b is emitted at the same angle as the angle (incident angle) between the line connecting the point A and the point B1 and the reflector 102b, but the light ray 105a is reflected at the point B2. Further, by being reflected at the point C on the side wall 102c, the exit angle tends to be narrower than the exit angle of the light beam 105b.

Therefore, as the plane reflector 102b on the front end face of the reflector 102 in the short side direction is extended, the influence of the reflected light beam 105a increases, and the light distribution range in the short side direction in the vicinity of substantially the center is increased. , It becomes narrow.

FIG. 9 is an example showing an experimental result of investigating the influence of the side wall of the reflector on the light distribution characteristics in the short side direction.

In FIG. 9, a curve 106a shown by a solid line
Indicates the light distribution characteristics in the short side direction when the side wall of the reflector is provided, and the curve 106b indicated by the dashed line indicates the light distribution characteristics in the short side direction when the side wall of the reflector is removed.

According to this, the light distribution characteristics outside the range of about ± 25 degrees with respect to the center position of the reflector 102 are substantially the same for both curves 106a and 106b, but about ± 2 degrees.
The light distribution characteristic from the inside of the range of 5 degrees is represented by a curve 106.
In the case b, the light emitted to the side is not reflected because there is no side wall, and goes out of the angle of view as it is, so that a substantially uniform light amount (guide number GNo.
5), a flat irradiation is obtained and a preferable result is obtained. However, the curve 106a is obtained by adding a light ray reflected on the side wall and condensed in the view angle.
The light quantity near the center increases, and the guide number GNo. =
The light amount is about 19. Therefore, the side wall of the reflector affects the light distribution characteristics in the short side direction, and extremely increases the amount of light near the center.
The technical means disclosed in Japanese Patent No. 41358 cannot obtain favorable light distribution characteristics.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object the light-emitting window on the front of the light-emitting unit is housed in the photographing lens barrel in a substantially downward direction. Another object of the present invention is to provide a flash device of a pop-up type camera which can obtain more efficient light distribution characteristics without increasing the size of the flash device itself and the outer shape of a camera on which the flash device is mounted.

[0021]

In order to achieve the above object, a strobe device for a camera according to a first aspect of the present invention is a pop-up type in which a light-emitting unit is housed on a taking lens barrel with a front side of the light-emitting unit being substantially downward. In the strobe device of this camera, the cross-sectional shape in the short side direction was formed into a substantially elliptical shape or a curved surface shape similar to this, and the opposite end surfaces in the short side direction were formed by reflecting surfaces extended by plane reflectors parallel to each other. A reflector, a straight tube-type flashlight discharge tube of a straight tube type disposed along the long side direction near the focal position of the substantially elliptical or approximated curved surface in the reflector, and near both ends of the flashlight discharge tube for light emission. The reflector is provided to extend to near the tip of the reflector, and reflects light in the long side direction of the discharge tube, and has both side walls of the reflector. Shooting Characterized by being formed in an arc shape along the outer circumferential surface of the lens barrel.

A strobe device for a camera according to a second aspect of the present invention is a strobe device for a pop-up camera which is housed on a photographic lens barrel with the front side of a light-emitting portion facing substantially downward. A reflector having a substantially elliptical shape or a curved surface shape approximating the same, and a reflector formed by a reflecting surface extending in the short side direction with a plane reflecting plate parallel to each other, and the substantially elliptical or approximating shape in the reflector; A straight tube-type flashlight discharge tube arranged along the long side near the focal position of the curved surface, and provided near both ends of the flashlight discharge tube for light emission and extended to near the tip of the reflector; Reflecting the light in the long-side direction of the discharge tube, and having both side walls of a reflector, wherein the both side walls are formed by being curved outward in the short side direction in an arc shape. You .

The strobe device for a camera according to the third invention is a strobe device for a pop-up camera which is housed on a photographic lens barrel with the front side of a light-emitting unit being substantially downwardly directed. A reflector having a substantially elliptical shape or a curved surface shape approximating the same, and a reflector formed by a reflecting surface extending in the short side direction with a plane reflecting plate parallel to each other, and the substantially elliptical or approximating shape in the reflector; A straight tube-type flashlight discharge tube arranged along the long side near the focal position of the curved surface, and provided near both ends of the flashlight discharge tube for light emission and extended to near the tip of the reflector; The reflectors are disposed on both side walls of the reflector, which reflect light in the long side direction of the discharge tube, and on the front opening window of the reflector, and transmit light emitted from the flashlight discharge tube for light emission. ; And a university panel, the optical panel includes a region in which most of the reflected light of the side walls is transmitted,
It is characterized in that it is formed of optical elements having different light condensing rates or light diffusing rates in the short side direction from other areas.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a front view of a camera equipped with a strobe device according to a first embodiment of the present invention.
Shows a side view of this camera. 1 and 2 show a state in which a part of the camera is crushed and the strobe device is housed in the camera body. FIG.
In FIG. 2, an outline indicated by a two-dot chain line will be described later, but shows a case where a conventional strobe device is mounted. In FIG. 2, the outline of the strobe device indicated by a two-dot chain line is This shows a state where the device is popped up.

The strobe device 1 has a straight tube type flash discharge tube 1a for emitting flash light, a reflector 2 for irradiating a light beam emitted from the discharge tube 1a forward, and a light reflected by the reflector 2. And an optical panel 3 for adjusting the light distribution characteristics of the luminous flux.
1 is provided so as to be rotatable with respect to the camera body 10. In this storage state, the reflector 2
The front opening window of the camera body 10 is accommodated in a substantially downward direction, and when the strobe device 1 is used, as shown by a two-dot chain line in FIG. Pops up towards the top.

The reflector 2 in the strobe device 1
Is a portion 2a in which the flash tube for light emission 1a is disposed.
Is formed in a substantially elliptical shape having an open front surface or a curved surface shape approximate to the elliptical shape, and the opposed front end surfaces in the short side direction are parallel to each other.
b, the left and right side surfaces of the parallel plane reflecting plate 2b and the substantially elliptical or curved surface portion 2a similar thereto are formed by reflecting surfaces extending forward, and both side walls also formed of a plane reflecting plate 2c.

Further, an optical panel 3 is disposed in a horizontally long rectangular opening window formed by the front end of the flat reflecting plate 2b and the front end of both side walls 2c. The front side of the front end portion of the flat reflecting plate 2b is formed in an arc shape along the outer peripheral shape of the photographing lens barrel 4. Therefore, the depth is formed to be shallower at substantially the center of the flat reflector 2b than near both ends.

A straight tube-type flash discharge tube 1a having an anode and a cathode at both ends is disposed along the long side near the focal point of a substantially elliptical or approximate curved surface in the reflector 2. I have.

According to the above-described first embodiment, the front edge of the flat reflecting plate 2b of the reflector 2 is formed in an arc shape so as to follow the outer peripheral shape of the taking lens barrel 4. Since the optical panel 3 is disposed at the front end window, the front end of the flat reflecting plate 2b is formed as a straight line in accordance with the depth dimension of the side wall 2c (the outline indicated by the two-dot chain line in FIG. ), The height of the camera body 10 in a state in which the strobe device 1 is stored can be reduced.

Further, the depth of the plane reflecting plate 2b is increased near both side walls 2c, and the light beam reflected by the plane reflecting plate 2b near the both side walls 2c is further reflected on the both side walls 2c, so that the light is not wastefully formed within the angle of view. Since light is condensed, the light amount distribution in the short side direction in the irradiation range of the strobe device 1 can be made substantially uniform (flat), and good light distribution characteristics without irradiation unevenness can be obtained. it can.

FIG. 3 is a perspective view showing only a reflector in a flash device according to a second embodiment of the present invention.

The reflector 2 of the strobe device 1
A has a cross section in the short side direction of a portion in which the flashlight discharge tube 1a for light emission is disposed is formed to have a substantially elliptical cross section or a curved surface shape similar thereto as in the first embodiment. However, the second embodiment is different from the second embodiment in that the side walls 2Ac on both sides are curved outward in an arc shape. By forming the side wall 2Ac of the reflector 2A in such a shape, the irradiation angle in the short side direction of the light beam reflected by the plane reflector 2b and further reflected on both side walls 2Ac and emitted forward of the reflector 2A in the short side direction. To
Further, it can be easily expanded.

In FIG. 3, the reflector 2
A case is shown in which the front edge of the flat reflecting plate 2b of A is formed in a straight line in accordance with the dimension in the depth direction of the side wall, but as in the first embodiment described above, the front end of the flat reflecting plate 2b is formed. If the edge is formed in an arc shape so as to follow the outer peripheral shape of the taking lens barrel 4, the same effect as in the first embodiment can be further obtained.

FIG. 4 is a diagram showing the trajectory of light rays reflected only on the right side wall 2c in the reflector 2 shown in the first embodiment. As shown in FIG. 4, most of the reflected light reflected by the side wall 2c is transmitted through the corresponding portion 3b of the optical panel 3 within the area 9b on the front side of the side wall 2c.

Therefore, by adjusting the light collection rate or the light diffusion rate in the short side direction of the optical panel 3 so as to be different between the substantially central region 9a and the both end regions 9b, the light is reflected by the side wall 2c. Light rays emitted forward and side wall 2
c, the light distribution that is emitted forward without being reflected by c, that is, the light distribution that is reflected only on the plane reflector 2b and emitted forward or the light emitted directly forward from the light emitting flash discharge tube 1a is aligned. The light amount distribution within the irradiation range of the strobe device 1 can be adjusted substantially uniformly.

That is, FIG. 5 is a front view of a strobe device according to a third embodiment of the present invention, and is an example of a strobe device adjusted so that a light amount distribution within an irradiation range becomes substantially uniform. is there. Note that the strobe device 1 of the third embodiment has substantially the same configuration as that of the above-described first embodiment. However, in the third embodiment, the strobe device 1 is disposed on the front side of the strobe device 1. The optical characteristics of the optical panel 3 are different.

That is, the portion 3b of the optical panel 3 corresponding to the regions 9b at both ends of the strobe device 1 is formed by a Fresnel lens having a high diffusivity for light in the short side direction passing through the portion 3b. The portion 3a corresponding to the central region 9a is an optical element having no diffusion effect for light rays in the short side direction of the reflector 2,
For example, it is formed by a transparent lens, a Fresnel lens having a high diffusion rate for light rays in the long side direction, a Fresnel lens having a high light collection rate for light rays in the short side direction, and the like. In addition,
FIG. 5 illustrates a case where the portion 3a is formed by a transparent lens.

FIG. 6 is a front view showing a modification of the flash device of the third embodiment.

In this modification, the optical panel 3 of the strobe device 1 has a substantially central region 9 in the strobe device 1.
a portion 3a corresponding to the region 9b is formed by a Fresnel lens having a high light-collecting rate with respect to light in the short side direction passing through the portion 3a.
Is an optical element having no light-condensing effect on light rays in the short side direction of the reflector 2, for example, a transparent lens, a Fresnel lens having a high light condensing rate for light rays in the long side direction, and a light ray in the short side direction. And is formed of a Fresnel lens having a high diffusion rate. FIG. 6 shows a case where the portion 3a is formed by a transparent lens.

According to the above-described third embodiment and its modified example, the light collecting rate or the light scattering rate in the short side direction of the optical panel 3 is reduced by the portion 3a corresponding to the substantially central region 9a. And portions 3 corresponding to the regions 9b at both ends.
Since light is formed and adjusted with different optical characteristics between b and b, the light amount distribution within the irradiation range of the strobe device 1 can be made substantially uniform, and more efficient light distribution characteristics can be obtained. it can.

[0041]

As described above, according to the present invention, in a pop-up type camera strobe device which is housed on a photographic lens barrel with the light-emitting portion having the front side substantially downward, the device itself and the mounting thereof are provided. It is possible to provide a camera strobe device that can obtain more efficient light distribution characteristics without increasing the external shape of the camera.

[Brief description of the drawings]

FIG. 1 is a front view of a camera equipped with a strobe device according to a first embodiment of the present invention.

FIG. 2 is a side view of the camera of FIG.

FIG. 3 is a perspective view showing a reflector in a strobe device according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of the reflector showing a trajectory of a light beam reflected only on the right side wall of the reflector in the strobe device of FIG. 1;

FIG. 5 is a front view of a strobe device according to a third embodiment of the present invention.

FIG. 6 is a front view showing a modification of the strobe device of FIG. 5;

FIG. 7 is a cross-sectional view of a reflector in a conventional strobe device.

FIG. 8 is a longitudinal sectional view of a reflector in the strobe device of FIG. 7;

FIG. 9 is a light distribution characteristic diagram showing an effect of a side wall of a reflector on light distribution characteristics in a short side direction in the strobe device of FIG. 7;

[Description of Signs] 1 ... Strobe device 2, 102 ... Reflector (reflection umbrella) 2b, 102b ... Planar reflector, reflector 2c, 102c ... Side wall (reflector) 3 ... Optical panel 4 ... Photographing lens Lens tube 10 Camera body

Claims (3)

[Claims] 1. A strobe device for a pop-up camera which is housed on a taking lens barrel with a front side of a light-emitting portion facing substantially downward, wherein a cross-sectional shape in a short side direction is a substantially elliptical shape or a curved shape approximating the same. And a reflector formed by extending a facing surface in the short side direction with a plane reflecting plate parallel to each other, and a near-focal point near the focal point of the substantially elliptical or approximate curved surface in the reflector along the long side direction. A light-emitting flash discharge tube of a straight tube type disposed in the vicinity of both ends of the light-emitting flash discharge tube, extending near the tip of the reflector, and extending in the long side direction of the discharge tube. A strobe device for a camera, comprising: a reflector; and a side wall portion of a reflector; and a substantially central portion of the opposed front end surface of the flat reflector formed in an arc shape along the outer peripheral surface of the taking lens barrel. 2. A strobe device for a pop-up camera which is housed on a taking lens barrel with a front side of a light-emitting portion facing substantially downward, wherein a cross-sectional shape in a short side direction is a substantially elliptical shape or a curved surface shape similar thereto. And a reflector formed by extending a facing surface in the short side direction with a plane reflecting plate parallel to each other, and a near-focal point near the focal point of the substantially elliptical or approximate curved surface in the reflector along the long side direction. A light-emitting flash discharge tube of a straight tube type disposed in the vicinity of both ends of the light-emitting flash discharge tube, extending near the tip of the reflector, and extending in the long side direction of the discharge tube. A strobe device for a camera, comprising: a reflector; and both side walls of a reflector, wherein the side walls are formed to be curved outward in a short side direction. 3. A flash device for a pop-up camera which is housed on a photographic lens barrel with a light-emitting portion having a front side substantially downward, wherein a cross-sectional shape in a short side direction is substantially elliptical or a curved surface shape similar thereto. And a reflector formed by extending a facing surface in the short side direction with a plane reflecting plate parallel to each other, and a near-focal point near the focal point of the substantially elliptical or approximate curved surface in the reflector along the long side direction. A light-emitting flash discharge tube of a straight tube type disposed in the vicinity of both ends of the light-emitting flash discharge tube, extending near the tip of the reflector, and extending in the long side direction of the discharge tube. The optical panel, which is disposed at a front opening window of the reflector and transmits light emitted from the flash tube for light emission, comprises: A region where most of the reflected light of the side wall portion is transmitted, the camera of the flash device which is characterized in that in the other regions, formed by different optical elements of light collection efficiency or diffuse light ratio in the short side direction.