JP5305871B2 - Illumination device with variable illumination angle and photographing device having the same - Google Patents

Description

  The present invention relates to an illumination device having a variable irradiation angle and a photographing device using the illumination device. For example, the present invention relates to an illuminating device that is attached to a part of a camera body (imaging device) or provided independently, and illuminates a subject by changing an irradiation angle of illumination light (flash) so as to be interlocked with a photographing operation of the camera. .

  Conventionally, in an illuminating device (strobe device) used in an imaging device such as a camera, the irradiation angle of a light beam emitted from a light source is changed in various ways so as to be condensed and irradiated within a required irradiation angle of view. An illumination device with variable illumination angle is known (Patent Documents 1 to 3).

  For example, depending on the focal length of the photographic lens of the photographic device, or when the photographic lens is a zoom lens, the illuminating angle can be changed in various ways corresponding to the photographic range corresponding to the zoom position. Are known (Patent Documents 4 and 5).

  FIG. 6 is a schematic view of the main part of an illumination device (photographic flash device) with variable illumination angle disclosed in Patent Document 1. In FIG. The illumination device with variable illumination angle shown in FIG. 6 includes a light control member (condensing lens) that can move in the irradiation direction in front of a light emitting section that includes a reflector 1 and a flash tube 2 disposed at the bottom of the reflector 1. ) It consists of a configuration with 3 arranged.

  By moving the condenser lens 3 from the solid line position X to the two-dot chain line Y, the irradiation angle of the light beam emitted from the condenser lens 3 can be changed.

  On the other hand, Patent Document 2 discloses an illumination device (flash device) having a variable illumination angle in which the illumination angle is changed by moving the flash tube and the reflector.

  Patent Document 3 discloses a strobe device in which the relative angle between the rod-shaped light source and the light control unit is changed to change the irradiation angle.

  In particular, in Patent Document 3, a diffusion control unit composed of a concave cylindrical lens that performs light diffusion only on the longitudinal direction of a rod-shaped light source on one surface constituting the light control unit in FIG. 3 and a direction perpendicular to the longitudinal direction. A condensing lens 8 that performs a condensing function is provided.

  On the other side, an illumination device with a variable irradiation angle is disclosed in which an annular lens is provided at the center and a condensing lens that condenses light only in the longitudinal direction is provided at both longitudinal ends.

In Patent Documents 4 and 5, there is provided an illumination device with a variable irradiation angle in which an optical means including a prism, a light guide, a condensing lens, and the like is provided in front of the light emitting unit, and a part of the optical means is moved to make the irradiation angle variable. Disclosure.
Japanese Utility Model Publication No. 53-62330 Japanese Unexamined Patent Publication No. 60-83921 JP 2004-138784 A Japanese Patent Laid-Open No. 2002-328412 JP 2003-5261 A

  Many illumination devices with variable illumination angles are configured by combining a reflector, a flashlight tube, and a Fresnel lens as a light control member. As is well known, a Fresnel lens has a structure in which a lens curved surface is subdivided into concentric lens curved surface portions.

  By the way, in recent years, along with the downsizing of the photographing apparatus, there is a demand for a compact illumination apparatus with a variable irradiation angle. In addition, as the zoom lens used in the photographing apparatus is increased in zoom, an illumination device with a variable illumination angle is required to achieve both a wide angle of illumination in the wide state and a high degree of light collection in the tele state.

  If the reflector is miniaturized in order to reduce the size of the lighting device, the area for controlling the reflected light becomes narrow, and therefore, uneven light distribution tends to occur particularly on the irradiated side in the wide state.

  In order to suppress uneven light distribution on the irradiated side at this time, it is necessary to provide a diffusion control unit in the light control member movable in the irradiation direction. However, if a diffusion control unit is provided on the entire surface of the light control member to enhance the diffusion characteristics, it becomes difficult to obtain a high light collection degree in the tele state.

  For this reason, in the illumination device with variable irradiation angle, the configuration of the light incident / exit surface of the light control member that is disposed in front of the light emitting unit, diffuses and emits incident light, and is relatively movable in the irradiation direction is appropriate. It becomes important to set to.

  It is an object of the present invention to provide an illumination device with a variable irradiation angle that can irradiate with a high degree of light condensing in a tele state while reducing uneven light distribution on the irradiated side in a wide state.

The illumination device with variable illumination angle according to the present invention includes a flash light-emitting unit composed of a light-emitting unit having a shape elongated in the first direction, and is disposed on the opposite side of the flash light-emitting unit from the irradiated side, and is emitted from the flash light-emitting unit. A reflector that reflects a part of the luminous flux to the irradiated side, and a light control means that is arranged on the illuminated side of the reflective umbrella and emits light by changing the diffusion characteristics of the incident luminous flux,
In the illumination device of variable illumination angle that changes the illumination angle by changing the relative position of the illumination direction of the flash light emitting unit and the light control means,
One surface of the light control means includes a first light control unit in which a central region in the first direction diffuses in a second direction orthogonal to the first direction, and both ends of the first light control unit in the first direction A second light control unit comprising a Fresnel lens having a light collecting property in the central direction, the other surface of the light control means being a diffusion control unit that performs a diffusion action in the second direction on the central region, and the diffusion A third light control unit that collects light in the first direction at both ends of the control unit in the first direction, and a fourth light that collects light in the second direction at both ends of the diffusion control unit in the second direction. It has a control part.

  ADVANTAGE OF THE INVENTION According to this invention, the illumination device of the irradiation angle variable which can irradiate with the high condensing degree in a tele state is obtained, reducing the light distribution nonuniformity by the side of irradiation in a wide state.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  The illumination device with variable illumination angle according to the present invention has a flash light-emitting portion composed of a light-emitting portion that is long in the first direction (for example, the horizontal direction). A long reflection in the first direction is arranged on the opposite side to the irradiated side with respect to the flash discharge tube and reflects a part of the light beam emitted from the flash light emitting part (for example, a light beam not emitted to the irradiated side) to the irradiated side. A reflective umbrella including a surface is included. Furthermore, it has the light control means which is arrange | positioned at the to-be-irradiated side of a reflector, and changes and changes the diffusion characteristic of incident light flux.

  And the irradiation angle is changed by changing the relative position of the irradiation direction of the flash light emitting part and the light control means.

[Example 1]
1 and 2 are longitudinal sectional views of main parts in a wide state and a tele state in Embodiment 1 of the illumination device with variable irradiation angle according to the present invention.

  The illumination device with variable illumination angle according to the present embodiment includes a reflector 1, a flash tube 2 disposed at the bottom of the reflector 1, and a light disposed in front of the light emitting unit 2 a of the flash tube 2 (subject OB side). And a control member (light control means) 3.

  The light control member 3 shown in FIG. 1 is placed in a tele state separated from the reflector 2 as shown in FIG. 2, so that the irradiation angle of the light beam emitted from the light emitting unit 2a is variable.

  FIG. 3 is a front view of the surface (one surface) facing the subject OB of the light control member 3 in this embodiment. The light control member 3 has a first light control unit 4 at the center of the surface 3b facing the subject OB and a second light control unit 5 at the periphery in the horizontal direction.

Specifically, one surface 3b of the light control means 3, a first light control portion central region of the first direction (X direction) to the diffusing function in a second direction perpendicular to the first direction (Y-direction) 4. Further, both end portions in the first direction of the first light control unit 4 have a second light control unit 5 made of a Fresnel lens having a light collecting property in the central direction.

  FIG. 4 is a front view of the surface 3 a facing the reflector 1 of the light control member 3 in this embodiment. The light control member 3 has a diffusion control unit 6 at the center of the surface (the other surface) 3a facing the reflector 1, a third light control unit 7 at the periphery in the first direction, and a third at the periphery in the second direction. A four-light control unit 8 is provided.

  Specifically, the other surface 3a of the light control means 3 has a diffusion control unit 6 that performs a diffusion action in the second direction in the central region. Further, the third light control unit 7 that condenses light in the first direction at both ends of the diffusion control unit 6 in the first direction, and the light condensing action in the second direction at both ends of the diffusion control unit 6 in the second direction. A fourth light control unit 8 is provided.

  The diffusion control unit 6 has an optical function of diffusing light incident from the flash tube 2 in a direction (Y direction) (vertical direction) perpendicular to the longitudinal direction (X direction) (horizontal direction) of the flash tube 2. . And by this optical action, the light distribution unevenness of the light beam to the irradiated side is suppressed.

  In this embodiment, the diffusion controller 6 has a configuration in which at least one of a cylindrical lens array, a microlens array, a diffusion plate, or a plurality of prisms having a triangular cross-sectional shape are arranged in the second direction.

  Here, the first light control unit 4 has a configuration including a prism array in which a plurality of prisms having a triangular cross section are arranged in the second direction.

  The second light control unit 5 has a configuration in which semicircular Fresnel lenses are arranged opposite to each other with the first light collection control unit 4 interposed therebetween.

  The third light control unit 7 includes a prism array in which a plurality of prisms having a triangular cross section are arranged on both sides in the first direction with the diffusion control unit 6 interposed therebetween.

  The fourth light control unit 8 includes a prism array in which a plurality of prisms having a triangular cross section are arranged on both sides in the second direction with the diffusion control unit 6 interposed therebetween.

  In the present embodiment, the opening of the reflector 1 is rectangular, and the lengths of the opening in the first direction and the second direction are W1 and H1, respectively.

  Further, the light incident / exit surface of the light control means has a rectangular shape, and the lengths of the light incident / exit surface in the first direction and the second direction are W2 and H2, respectively.

At this time, the opening area R of the reflector 1 is
R = H1 × W1
It becomes.

Further, in the light control member 3, the area D of the diffusion control unit 6 is D = H2 × W2.
It is.

The opening area R and area D are:
H1 × W1 <H2 × W2 <2 × H1 × W1 (1)
H1 <H2 (2)
W1 <W2 (3)
To satisfy the following conditions.

  If the lower limit of Equation (1) is not reached, a part of the light emitted from the flash tube 2 enters the third light control unit 7 or the fourth light control unit 8 in the wide state shown in FIG. For this reason, the diffusion effect by the diffusion control unit 6 cannot be obtained, and uneven light distribution of the light beam toward the irradiated side is likely to occur. Further, when exceeding the upper limit value of the formula (1), in the tele state shown in FIG. 2, the amount of light emitted from the flash light emitting tube 2 incident on the third light control unit 7 and the fourth light control unit 8 is small. A sufficient degree of light collection cannot be obtained.

  According to the illumination device with variable illumination angle having the above-described configuration, in the wide state (FIG. 1), the light emitted from the flash tube 2 is diffused by the diffusion control unit 6, so that the light flux is distributed to the irradiated side. Generation of unevenness is suppressed.

  In the tele state (FIG. 2), a part of the light emitted from the flash tube 2 enters the third light control unit 7 and the fourth light control unit 8 and is collected. The degree of light collection is increased.

  As described above, according to this embodiment, it is possible to irradiate the irradiated side with a high degree of light condensing in the tele state while reducing uneven light distribution on the irradiated side in the wide state.

  Note that the illumination device with variable illumination angle according to the present invention can be detachably attached to the imaging device, or can be provided independently of the imaging device.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

1 is a longitudinal sectional view in a wide state of a lighting device with variable irradiation angle according to Embodiment 1 of the present invention. 1 is a longitudinal sectional view of a tele state of a lighting device with variable irradiation angle according to a first embodiment of the present invention. 1 is a front view of a surface of a light control member according to a first embodiment of the present invention that faces a subject. The front view of the opposing surface with the reflector of the light control member which concerns on Example 1 of this invention. 1 is a cross-sectional view in a wide state of a lighting device with variable irradiation angle according to a first embodiment of the present invention. Vertical section of a conventional illumination device with variable illumination angle

Explanation of symbols

1. Reflective umbrella 2. Flash arc tube 3. Light control member First light control unit 5. Second light control unit 6. 6. Diffusion control unit Third light control unit 8. Fourth light control unit

Claims (5)

A flash light-emitting part composed of a light-emitting part that is long in the first direction, and disposed on the opposite side to the irradiated side with respect to the flash light-emitting part, and reflects a part of the light beam emitted from the flash light-emitting part to the irradiated side And a light control means that is arranged on the irradiated side of the reflector and changes the diffusion characteristics of the incident light beam and emits it,
In the illumination device of variable illumination angle that changes the illumination angle by changing the relative position in the illumination direction of the flash light emitting unit and the light control means,
One surface of the light control means includes a first light control unit in which a central region in the first direction diffuses in a second direction orthogonal to the first direction, and both ends of the first light control unit in the first direction A second light control unit comprising a Fresnel lens having a light collecting property in the central direction, the other surface of the light control means being a diffusion control unit that performs a diffusion action in the second direction on the central region, and the diffusion A third light control unit that collects light in the first direction at both ends of the control unit in the first direction, and a fourth light that collects light in the second direction at both ends of the diffusion control unit in the second direction. An illumination device with a variable irradiation angle, comprising a control unit. The opening of the reflector is rectangular, the lengths of the opening in the first direction and the second direction are W1 and H1, respectively, and the light incident / exit surface of the light control means is rectangular, the light incident / exit surface H1 × W1 <H2 × W2 <2 × H1 × W1 when the lengths of the first direction and the second direction are W2 and H2, respectively.
H1 <H2
W1 <W2
The illumination device with variable irradiation angle according to claim 1, wherein the following condition is satisfied.   The illumination device with variable irradiation angle according to claim 1, wherein the diffusion control unit includes at least one of a cylindrical lens array, a microlens array, and a diffusion plate.   4. The illumination device with variable irradiation angle according to claim 1, wherein the first, third, and fourth light control units include a prism array in which prisms having a triangular cross section are arranged.   An imaging apparatus comprising the illumination device with variable illumination angle according to claim 1 detachably.