JP5349871B2 - Strobe device - Google Patents

Description

  The present invention relates to a strobe device for irradiating an irradiation target with strobe light as auxiliary light for photographing.

  For example, a strobe device built in a digital camera or the like directs strobe light to the irradiation target to enable shooting within a predetermined effective shooting range even in a dark environment such as at night or in the rain. An example of the structure is shown in FIG.

  That is, FIG. 10 is a perspective view of a conventional strobe device. The strobe device 101 shown in FIG. 10 has a light source 102 composed of a xenon tube or the like that is long in the width direction (X-axis direction), and a strobe light emitted from the light source 102. And a reflector 103 that reflects toward the subject, and a rectangular plate-like lens (not shown) that covers the front surface (light emitting surface) of the reflector 103.

  The reflector 103 includes a front reflecting surface (vertical wall) 103A having a parabolic curved surface or a semi-elliptical curved surface, and flat side reflecting surfaces (horizontal walls) 103B formed at both ends thereof. Most of the emitted strobe light is primarily controlled in the reflection direction (light quantity distribution) by the front reflecting surface (vertical wall) 103A and the side reflecting surface (horizontal wall) 103B of the reflector 103. Then, the reflected light primarily controlled by the reflector 103 is secondarily controlled (light distribution) by a lens (not shown) that has been cut and irradiated with a shooting angle of view as shown in FIG. Suitable light quantity and light distribution characteristics can be obtained.

  By the way, in Patent Document 1 regarding such a strobe device, a xenon tube as a light source and a reflection member of a cover lens are provided, and light directed from the xenon tube directly to the cover lens is reflected by the reflection member toward the reflector, so that the emitted light is reflected. A configuration has been proposed in which almost all of the light distribution direction is controlled by a reflector to obtain a desired light distribution characteristic and to increase the reach distance of light.

  Further, Patent Document 2 discloses a light source for a reflector reflecting surface in a strobe device that can adjust an irradiation angle of an object to be irradiated with reflected light by adjusting a relative distance on the optical axis between the light source and the reflector reflecting surface. The cross-sectional shape in a direction perpendicular to the axis of the light source is a substantially parabolic shape, and the distance between both ends of the reflector reflecting surface in the direction along the axis of the light source and the light source is the both ends of the reflector reflecting surface in the direction along the axis of the light source. By setting the reflector parabolic shape of the reflector reflecting surface to be smaller from the central part in the longitudinal direction to both sides, the light distribution width can be changed to the left and right without causing an increase in the size of the device. An extended configuration has been proposed.

Further, Patent Document 3 discloses a strobe in which at least a part of a longitudinal sectional shape of a reflector is inclined so that reflected light of a light source is directed inward to increase the use of light collected in the tube axis direction. A device has been proposed.
Japanese Patent Laid-Open No. 2003-161988 JP 2008-089551 A Utility Model Registration No. 3044036

  However, in the conventional strobe device 101 shown in FIG. 10, the front reflecting surface (vertical wall) 103A of the reflector 103 is formed of a uniform curved surface continuous in the width direction. It is difficult to efficiently obtain effective light distribution because the degree of freedom of control is small, the light distribution is excessively widened, or the central light quantity is decreased. In particular, with the miniaturization of the camera, the reflector of the strobe device is also miniaturized, and in the current situation where the area of the reflecting surface is reduced and the space is limited, ideal reflection is realized within the uniform reflecting surface of the reflector. This is difficult, and even if an attempt is made to install a surface that reflects light toward the center of the field of view and a surface that reflects light toward the wide-angle side, it is impossible to achieve this because of space limitations.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a strobe device capable of realizing efficient photographing light distribution by increasing the degree of freedom of primary control of light by a reflector. There is.

To achieve the above object, the present invention provides a strobe device including a light source that emits strobe light and a reflector that reflects the strobe light from the light source toward an irradiation target.
As the reflecting surface of the reflector, a first reflecting surface that condenses at the center of the photographing field angle and a second reflecting surface that condenses at the photographing field angle wide angle side are alternately arranged in the longitudinal direction of the light source,
The second reflecting surface has two curved surfaces that divide the light distribution angle of light incident on the reflector into two, and one curved surface closer to the light source directs the light from the light source diagonally. The other curved surface on the side far from the light source is configured to reflect the light from the light source toward the forward direction on the same side as the curved surface,
The first reflecting surface and the second reflecting surface that are adjacent in the longitudinal direction of the light source are connected by a stepped surface that is inclined, and the light traveling toward the center of the photographing field angle is transmitted through the stepped surface in the peripheral direction of the photographing field angle. It is characterized in that the reflecting surface is shaped to be dispersed in the surface .

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According to the present invention, the first reflecting surface is arranged in the longitudinal direction of the light source alternately because the first reflecting surface that condenses at the center of the shooting angle of view and the second reflecting surface that focuses on the wide angle side of the shooting angle of view are arranged. The light collected at the center of the shooting angle of view and the light focused on the wide angle side of the shooting angle of view by the second reflecting surface are combined to increase the degree of freedom of primary control of the light by the reflector, which is efficient. Shooting light distribution is realized.

Further , according to the present invention, the first reflecting surface and the second reflecting surface which are adjacent in the longitudinal direction of the light source are connected by the stepped surface which is inclined, and the stepped surface is photographed toward the center of the photographing field angle. Since the reflecting surface has a shape that is dispersed in the peripheral direction of the angle of view, light that is greatly inclined from the light irradiation direction can be reflected by the step surface to approach the light irradiation direction, and the light condensing performance in the primary control by the reflector can be improved. Can be increased.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 is a perspective view of a strobe device according to the present invention, FIG. 2 is a plan view of the strobe device, FIG. 3 is a cross-sectional view taken along line AA in FIG. 2, FIG. 4 is a cross-sectional view taken along line BB in FIG. 5 is a sectional view showing the first reflecting surface of the reflector and a plan view showing the light distribution image, FIG. 6 is a sectional view showing the second reflecting surface of the reflector and a plan view showing the light distribution image, and FIG. FIG. 7A is a diagram showing a light distribution of a strobe device according to the present invention, and FIG. 7B is a diagram showing a light distribution of a conventional strobe device.

  A strobe device 1 according to the present invention is built in, for example, a digital camera, and has a circular tubular light source 2 composed of a xenon tube or the like that is long in the width direction (left-right direction in FIGS. 1 to 3), and the light source 2. A horizontally long reflector 3 that reflects strobe light emitted from the object toward the subject to be irradiated, and a rectangular plate-like lens 4 that covers the front surface (light emitting surface) of the reflector 3 (shown by a chain line in FIG. 4) It has. The lens 4 is a Fresnel-shaped lens that has been cut to obtain a desired light distribution pattern.

  Thus, the reflector 3 for primarily controlling the light distribution of the strobe device 1 according to the present invention includes a front reflecting surface (vertical wall) 3A and flat side reflecting surfaces (horizontal walls) 3B formed on both side ends thereof. In the front reflection surface (vertical wall) 3A, two types of reflection surfaces 3a and 3b having different light distribution curves are arranged in the longitudinal direction (width direction) of the light source 2. In the present embodiment, the first reflecting surface 3a and the second reflecting surface 3b having different light distribution curves are alternately arranged in the longitudinal direction of the light source 2, and the second reflecting surface 3b is arranged at the center in the width direction. The first reflecting surfaces 3a are arranged on both sides thereof. The reflector 3 is obtained by press molding of sheet metal or integral molding of resin, and the reflection surfaces (inner surfaces) 3A and 3B are subjected to a reflection treatment such as aluminum vapor deposition as necessary to increase the reflectance.

Here, the first reflecting surfaces 3 a arranged on the left and right sides of the reflector 3 have a first focal point at the center of the light source 2 and are taken images at an arbitrary distance (for example, 0.5 m) from the light source 2. A part of an ellipse having a second focal point at the center of the corner is provided as a light distribution curve. As shown in FIG. 5, the light L emitted from the light source 2 is incident on the first reflecting surface 3a. Reflected and focused at the center of the field of view. That is, since the first reflecting surface 3a has an elliptical shape in a cross section orthogonal to the cylindrical light source 2, the light distribution of the strobe device 1 brightens the center of the photographing field angle, in other words , the region of the light source 2. .

Further, the second reflecting surface 3b disposed at the center in the width direction of the reflector 3 has two curved surfaces that divide the light distribution angle of the light incident on the reflector 3, and as shown in FIG. When the direction is the forward direction, the portion close to the light source 2 is focused on the wide angle portion opposite to the shooting field angle, and the portion far from the light source 2 is focused on the wide angle portion on the forward direction side. That is, the second reflecting surface 3 b is roughly divided into two reflecting regions in a cross section perpendicular to the cylindrical light source 2. The reflection surface 3b1 near the light source 2 reflects the light from the light source 2 in the diagonal direction, and the reflection surface 3b2 far from the light source 2 reflects the light from the light source 2 on the same side as the reflection surface 3b2. Reflect toward the forward direction. As a result, in the wide-angle portion on the diagonal side, the light from the forward reflecting surface 3b1 (right side in FIG. 6) and the combined light from the reflecting surface 3b2 on the opposite side in the forward direction (left side in FIG. 6) get drunk . In the forward wide-angle portion, the light distribution is obtained by combining light from the reflection surface 3b1 on the opposite side in the forward direction (left side in FIG. 6) and light from the reflection surface 3b2 in the forward direction side (right side in FIG. 6). Light distribution. 5 and 6, only the light L reflected on one side (the right half in the figure) of the first and second reflecting surfaces 3a and 3b is shown.

  By the way, although the surface which connects the 1st reflective surface 3a and the 2nd reflective surface 3b from which a light distribution curve differs is the level | step difference surface 3c, this level | step difference surface 3c is made into the reflective surface. Here, the step surface 3c is inclined by an angle α shown in the XZ plane as shown in FIG. 2, and is inclined by an angle β shown in the XY plane as shown in FIG. Has been. In the present embodiment, the step surface 3c is a flat surface, but may be a curved surface. By using the step surface 3c for reflection, light greatly inclined from the light irradiation direction (Y direction) can be brought closer to the Y direction. That is, light control in the longitudinal direction (X direction) of the cylindrical light source 2 is possible. Specifically, a reflective surface having a shape that disperses light traveling toward the center of the shooting angle of view in the peripheral direction of the shooting angle of view is formed in the step portion 3c.

  The strobe device 1 according to the present embodiment irradiates a subject with strobe light in order to enable photographing within a predetermined photographing effective range even in a dark environment such as at night or in the rain. However, when sufficient brightness required for photographing cannot be secured, strobe light is emitted from the light source 2 of the strobe device 1 in synchronization with an operation of a shutter button (not shown).

  Most of the strobe light emitted from the light source 2 is irradiated toward the reflector 3, is reflected by the reflecting surfaces 3 </ b> A and 3 </ b> B of the reflector 3, is primarily controlled, travels toward the subject, and passes through the lens 4. Is distributed to the subject and subjected to secondary control, and then is irradiated toward the subject as auxiliary light, enabling photographing within a photographing effective range in a dark environment.

  Thus, in the strobe device 1 according to the present embodiment, as described above, the first reflecting surface 3a that collects light at the center of the shooting angle of view is used as the front reflecting surface (vertical wall) 3A of the reflector 3 on both the left and right sides. Since the second reflecting surface 3b that condenses on the wide side of the shooting angle of view is arranged in the middle, the light that is condensed at the center of the shooting angle of view by the first reflecting surface 3a and the second reflecting surface 3b As a result, the light condensed on the wide angle side of the photographic field angle is combined, and the degree of freedom of primary control of the light by the reflector 3 is increased, thereby realizing efficient photographic light distribution.

In the present embodiment, since the stepped surface 3c connecting the first reflecting surface 3a and the second reflecting surface 3b having different light distribution curves is used as a reflecting surface, as shown in FIG. The light L1 that is greatly inclined from the Y direction) is reflected by the step surface 3c to prevent the reflected light from being concentrated near the center of the field of view as indicated by the arrow L1 ′, and the light quantity uniformity of the field of view is improved. Enhanced. In addition, since the light L2 reflected by the side reflecting surface (horizontal wall) 3B of the reflector 3 is also brought close to the Y direction, the light condensing performance in the primary control by the reflector 3 is enhanced.

  The present invention is particularly effective in a small-sized strobe device. According to the study by the present inventors, when the frontage C (see FIG. 4) and the tube diameter of the light source 2 are compared, the frontage C is larger than 2.5 times the tube diameter. Since the area of the reflective surface that can be increased is large, the uniformity within the shooting angle of view can be kept relatively good. However, when it becomes 2.5 times or less, the available reflective surface is small, so The illuminance difference between the peripheral part and the central part of the corner increases. However, according to the strobe device 1 according to the present invention, it is possible to obtain the same uniformity as that of a conventional single reflecting surface in the case of a front opening exceeding 2.5 times the tube diameter, despite the small front opening C. .

  As a result of the above, according to the strobe device 1 according to the present invention, as shown in FIG. The ideal light distribution can be obtained within the photographing field angle with respect to the light distribution obtained by the conventional strobe device 101 (see FIG. 10). Note that the light amount distributions shown in FIGS. 7A and 7B are displayed with the light amount at the center of the shooting angle of view as 100%.

Next, each of the alternative embodiment of the present invention in FIGS.

  8 and 9 are perspective views of a strobe device according to another embodiment of the present invention. In the strobe device 1 ′ shown in FIG. 8, the front reflection surface (vertical wall) 3A serves as the center of the photographing field angle of the reflector 3. FIG. The first reflecting surface 3a for condensing is disposed at the center in the width direction, and the second reflecting surface 3b for condensing on the wide angle side of the photographic field angle is disposed on both sides of the first reflecting surface 3a.

  In the strobe device 1 ″ shown in FIG. 9, three first reflecting surfaces 3a and two second reflecting surfaces 3b are alternately arranged in the width direction as a front reflecting surface (vertical wall) 3A. Specifically, the first reflecting surface 3a is disposed at the center of the reflector 3 in the width direction, the second reflecting surfaces 3b are disposed on both the left and right sides thereof, and the first reflecting surfaces 3a are disposed on both the left and right sides thereof. doing.

  Thus, the strobe devices 1 ′ and 1 ″ shown in FIGS. 8 and 9 can obtain the same effects as described above.

  The present invention can be applied to a strobe device mounted on a digital camera, a film camera, a mobile phone or the like.

1 is a perspective view of a strobe device according to the present invention. 1 is a plan view of a strobe device according to the present invention. AA line sectional view of FIG. BB sectional view of FIG. It is sectional drawing which shows the 1st reflective surface of the reflector of the strobe device which concerns on this invention, and a top view which shows a light distribution image. It is sectional drawing which shows the 1st reflective surface of the reflector of the strobe device which concerns on this invention, and a top view which shows a light distribution image. (A) is a figure which shows the light distribution of the strobe device based on this invention, (b) is a figure which shows the light distribution of the conventional strobe device. It is a perspective view of the strobe device which concerns on another form of this invention. It is a perspective view of the strobe device which concerns on another form of this invention. It is a perspective view of the conventional strobe device. It is a perspective view which shows the strobe light distribution which irradiates the imaging | photography field angle of a strobe device.

Explanation of symbols

1,1 ', 1 "Strobe device 2 Light source 3 Reflector 3A Reflector front reflecting surface (vertical wall)
Side reflection surface (horizontal wall) of 3B reflector
3a First reflective surface 3b Second reflective surface 3b1, 3b2 Reflective surface 3c Stepped surface 4 Lens C Frontage L, L1, L2 Light

Claims (1)

In a strobe device including a light source that emits strobe light and a reflector that reflects the strobe light from the light source toward an irradiation target,
As the reflecting surface of the reflector, a first reflecting surface that condenses at the center of the photographing field angle and a second reflecting surface that condenses at the photographing field angle wide angle side are alternately arranged in the longitudinal direction of the light source,
The second reflecting surface has two curved surfaces that divide the light distribution angle of light incident on the reflector into two, and one curved surface closer to the light source directs the light from the light source diagonally. The other curved surface on the side far from the light source is configured to reflect the light from the light source toward the forward direction on the same side as the curved surface,
The first reflecting surface and the second reflecting surface that are adjacent in the longitudinal direction of the light source are connected by a stepped surface that is inclined, and the light traveling toward the center of the photographing field angle is transmitted through the stepped surface in the peripheral direction of the photographing field angle. A strobe device characterized by having a reflecting surface with a shape to be dispersed .

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