JP2012181542A - Optical member, strobe device including optical member, and image recording apparatus incorporating strobe device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical member which covers a wide range of irradiation angle without changing optical characteristics, a strobe device including the optical member, and an image recording apparatus incorporating the strobe device.SOLUTION: An optical member 3 is disposed so that its position can be displaced relative to a rectangular aperture 7 of a light emitting unit 8 comprising a reflector 1 having a reflecting surface continuous to the rectangular aperture 7 and a bar-shaped light source 2 disposed so that its position is fixed or can be displaced relative to a bottom of the reflector 1. The optical member 3 has a first condenser lens 11 formed in a region facing the rectangular aperture 7 and has a second condenser lens 12 formed in a region other than the region facing the rectangular aperture 7 and has such optical characteristics that an irradiation angle at which the light emitting unit 8 in an arbitrary position is irradiated with illuminating light by the first condenser lens 11 is wider than an irradiation angle at which the light emitting unit 8 is irradiated with illuminating light by the second condenser lens 12.

Description

  The present invention relates to an optical member disposed in the opening of a light-emitting unit comprising a reflector having a reflecting surface continuous with the opening and a light source, a strobe device provided with the optical member, and an image recording apparatus incorporating the strobe device. More specifically, an optical member corresponding to a change in illumination angle of illumination light by changing a relative position between the optical member and the light emitting unit, a strobe device provided with the optical member, and an image recording apparatus incorporating the strobe device About.

  Conventionally, in a strobe device as an artificial light source used at the time of shooting with an image recording device such as a camera, when changing the shooting angle of view, that is, changing the irradiation angle of illumination light in accordance with the change in shooting magnification, it is provided on the light emitting unit and the front of the light emitting unit The irradiation angle was changed by changing the relative distance to the condensing lens (optical member). That is, in the case of wide-angle illumination that widens the irradiation angle, the light-emitting portion and the condensing lens are brought close to each other, and in the case of narrow-angle illumination that narrows the irradiation angle, the light-emitting portion and the condensing lens are separated. In addition, when the light-emitting unit is composed of a light source and a reflector, it is possible to respond to the illumination angle change by changing the relative distance between the light source and the reflector, and the light source and the reflector are separated from each other during wide-angle illumination. During the narrow-angle illumination, the light source and the reflector are close to each other.

  Various configurations of the condensing lens have been proposed so that the same condensing lens can be used in the above-described configuration and the irradiation angle can be changed in the widest possible range.

  However, in practice, it is difficult to cope with a wide range of illumination angle changes using the same condenser lens. For example, the focal length conversion value of a 35 mm film camera is a wide angle of about 17 mm (hereinafter referred to as “super wide angle”). ) Or a narrow angle with a focal length of about 135 mm (hereinafter referred to as “ultra-narrow angle”), the optical characteristics of the condenser lens toward either the ultra-wide angle or the ultra-narrow angle are optional. A panel was installed to supplement the optical characteristics of the condenser lens.

  Therefore, focusing on bringing the light emitting unit close to the condensing lens during wide-angle imaging, it has been proposed to form a diffusion optical system in the range of the condensing lens that is in contact with the opening of the reflector of the light emitting unit (for example, a patent). Reference 1).

JP-A-6-175203

  However, in the configuration described in the above-mentioned patent document, since the diffusion optical system is formed in a part of the condenser lens, the light incident on the diffusion optical system is diffused at the time of narrow-angle illumination. Condensation was not obtained, and this was the cause of a decrease in guide number during narrow-angle illumination.

  Accordingly, an object of the present invention is to provide an optical member corresponding to a wide range of irradiation angles without changing optical characteristics, a strobe device provided with the optical member, and an image recording device incorporating the strobe device. To do.

  The optical member of the present invention is capable of relative position displacement with respect to the opening of the light emitting unit including a reflector having a reflecting surface continuous with the opening and a light source disposed so as to be capable of relative position displacement with respect to the bottom of the reflector. The first condensing optical system is formed in a region facing the opening, and the second condensing optical system is formed in a region other than the region facing the opening, The first condensing optical system is a convex lens having a focal length longer than that of the second condensing optical system.

  In this way, since the first condensing optical system is formed in a region facing the opening of the light emitting unit, the first condensing system is almost the same during wide-angle illumination, that is, when the light emitting unit is close to the optical member. Only the optical optical system functions, and at the time of narrow-angle illumination, that is, when the light emitting unit is separated from the optical member, both the first condensing optical system and the second condensing optical system function. Here, in the convex lens, the longer the focal length, the wider the light distribution angle, and the shorter the focal length, the narrow the light distribution angle. Therefore, the first condensing optical system is designed so that the required super-wide-angle characteristics can be obtained when the light emitting unit is brought close to the optical member. Designed to obtain the required ultra-narrow angle characteristics when separated from the super-wide angle, which was not possible with the conventional configuration by driving the light-emitting unit without installing an optional panel. It will be able to handle both ultra narrow angles.

  Further, the first condensing optical system and the second condensing optical system may be a Fresnel lens, and the optical member is composed of one or a plurality of translucent members, The optical powers of the first condensing optical system and the second condensing optical system may be formed dispersed on each surface of each translucent member, and the optical member may be A diffusion optical system for diffusing the optical power of the second condensing optical system and the second condensing optical system, or the entire region where the first condensing optical system and the second condensing optical system are formed, or It may be formed so as to overlap a part.

  The strobe device of the present invention is characterized by the optical member. In this way, it is possible to provide a strobe device that can cope with both an ultra-wide angle and an ultra-narrow angle, which has not been obtained conventionally by only driving the light emitting unit, without installing an optional panel separately. Of course, such a strobe device may be built in a housing of an image recording device such as a camera, or may be housed in a single housing separate from the image recording device.

  The image recording apparatus of the present invention includes the strobe device. In this way, when changing the illumination angle of the strobe device according to the change in the shooting angle of view during zoom shooting, even if an optional panel is not installed separately, it is not possible to obtain it by simply driving the light emitting unit. It is possible to provide an image recording apparatus that can handle both wide-angle and ultra-narrow angle of view.

  As described above, according to the optical member of the present invention, the first condensing optical system is formed in the region facing the opening of the light emitting unit. Is designed so that the required ultra-wide angle characteristics can be obtained when the is placed close to the optical member, and for the second condensing optical system, the required ultra-narrow angle characteristics are obtained when the light emitting part is separated from the optical member. By adopting such a design, it becomes possible to cope with both an ultra-wide angle and an ultra-narrow angle, which could not be obtained in the prior art by only driving the light emitting unit, without installing an optional panel separately.

  Further, according to the strobe device of the present invention, since it is configured as a strobe device provided with the above-described optical member, even if an optional panel is not separately installed, it is an ultra-wide angle that cannot be obtained conventionally by only driving the light emitting unit. A strobe device that can handle both ultra-narrow angles can be provided.

  In addition, according to the image recording apparatus of the present invention, since the image recording apparatus includes the strobe device having the optical member described above, the irradiation angle of the strobe device can be set according to the change of the shooting angle of view during zoom shooting. In the case of changing, it is possible to provide an image recording apparatus that can cope with both a super-wide angle and a super-narrow angle of view, which has not been obtained conventionally only by driving the light emitting unit, without separately installing an option panel.

The perspective view which showed the positional relationship of the optical member which concerns on Embodiment 1 of this invention, and a light emission part. Image sectional drawing which showed the positional relationship of the light emission part in each of the time of wide angle illumination and the time of narrow angle illumination concerning Embodiment 1 Front view of the optical member according to the first embodiment AA sectional view of the optical member concerning Embodiment 1 BB sectional view of the optical member according to Embodiment 1 Light distribution characteristic diagram at the time of wide-angle irradiation according to the first embodiment Light distribution characteristic diagram during narrow-angle irradiation according to the first embodiment Front view of an optical member according to Embodiment 2 of the present invention CC sectional view of the optical member according to the second embodiment DD sectional view of the optical member according to Embodiment 2 Image sectional drawing which shows the lens structure of the optical member which concerns on other embodiment of this invention. Front view of an optical member according to another embodiment of the present invention

(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the optical member 3 according to the first embodiment includes a reflector 1 having a substantially parabolic reflecting surface 4 and a side reflecting surface 5 connected to a rectangular opening, and the substantially parabolic reflecting surface. 4 is arranged opposite to the rectangular opening 7 of the light emitting part 8 including the rod-like light source 2 as a light source arranged along the longitudinal direction of the rectangular opening 7 of the reflector 1 so as to be displaceable relative to the bottom part 6 of the reflector 4. Has been. For example, the optical member 3 is fixedly disposed on an external housing (not shown) that forms the exterior of the apparatus, and the light emitting unit 8 is movably disposed with a driving mechanism (not shown) so that the relative position can be displaced. Has been.

  A Fresnel lens having the optical characteristics of a convex lens is formed on the surface of the optical member 3 on the subject side, and the entire optical member 3 has a condensing characteristic. In the case of wide-angle illumination, the light emitting unit 8 and the optical member 3 are brought close to each other, and in the case of narrow-angle illumination, the light emitting unit 8 and the optical member 3 are separated from each other.

  In the first embodiment, the illumination angle of the illumination light from the rectangular opening 7 is also changed by changing the relative distance between the rod-shaped light source 2 and the reflector 1, and the rod-shaped light source 2 at the time of wide-angle illumination. And the reflector 1 are separated from each other, and the rod-shaped light source 2 and the reflector 1 are brought close to each other during narrow-angle illumination. In particular, the narrowest angle is obtained when the rod-like light source 2 is positioned at the focal position of the substantially paraboloidal reflecting surface 4 of the reflector 1.

  The optical member 3 according to the first embodiment is characterized in that the Fresnel lens is divided into a first condenser lens 11 and a second condenser lens 12. Hereinafter, a specific description will be given with reference to FIG.

  In the drawing, the light emitting unit 8 at the time of wide angle illumination is indicated by a solid line, and the light emitting unit 8 at the time of narrow angle illumination is indicated by a broken line. The first condenser lens 11 is formed in a region w that faces the rectangular opening 7, and a second condenser lens 12 is formed in a region t other than the region that faces the rectangular opening 7. The first condenser lens 11 has an optical characteristic that has a longer focal length than the second condenser lens 12. That is, the focal point W of the first condenser lens 11 is set farther than the focal point T of the second condenser lens 12.

  3 to 5, the shape of the Fresnel lens of the optical member 3 will be described in detail.

  The first condensing lens 11 has a plurality of concentric circular vertices 13 and 14 and a lens curved surface connected to the apexes 13 and 14 arranged with a separation distance of about 1/2 of the longitudinal dimension in the region w defined in FIG. Are divided into a plurality of lens curved surfaces 15 and 16 by wall surfaces 17 and 18 to form Fresnel lenses 19 and 20, and further pass through the vertices 13 and 14 and are straight lines 21 and 22 parallel to the short side direction of the optical member 3. A cylindrical lens 23 is formed in a region surrounded by the cylindrical lens 23.

  The second condenser lens 12 divides a lens curved surface connected to the center 24 into a plurality of lens curved surfaces 26 by a plurality of concentric wall surfaces 25 with a center 24 set on the rectangular optical member 3 as a vertex. Thus, the Fresnel lens 27 is formed.

  The two Fresnel lenses 19 and 20 in the first condenser lens 11 are set to have a longer focal length than the Fresnel lens 27 of the second condenser lens 12. The cylindrical lens 23 is an optical characteristic that narrows the light distribution characteristic in the vertical direction, that is, in the direction orthogonal to the longitudinal direction of the rod-shaped light source 2 during narrow-angle illumination (when the light emitting unit 8 is separated from the optical member in FIG. 2). have.

  The operation and effect of the above configuration will be described with reference to FIG. In the figure, a solid line arrow 41 indicates an optical path of irradiation light from the rectangular opening 7 at the time of wide-angle illumination, that is, when the light emitting unit 8 is closest to the optical member 3, and a two-dot chain line arrow 42 is at the time of narrow-angle illumination. That is, the optical path of the irradiation light from the rectangular opening 7 when the light emitting unit 8 is farthest from the optical member 3, and the broken line arrow 43 is the first of the irradiation light indicated by the two-dot chain line arrow 42 during narrow-angle illumination. The optical path of the light which permeate | transmits the 2nd condensing lens 12 is shown.

  Since the first condensing optical system is formed in the region w facing the rectangular opening 7 of the light emitting unit 8, the first condensing system is almost the same during wide-angle illumination, that is, when the light emitting unit 8 is close to the optical member 3. Only the optical lens 11 functions, and at the time of narrow-angle illumination, that is, when the light emitting unit 8 is separated from the optical member 3, both the first condenser lens 11 and the second condenser lens 12 function. . Therefore, as shown in FIG. 2, the light distribution image of the solid line arrow 41 is obtained during the wide-angle illumination, and the light distribution image of the broken line 43 is obtained during the narrow-angle illumination. Here, the first condenser lens 11 is designed to obtain a required super-wide-angle characteristic when the light emitter 8 is brought close to the optical member 3. By designing so that the required ultra-narrow angle characteristics can be obtained when the 8 is separated from the optical member 3, both the ultra-wide angle and the ultra-narrow angle that cannot be obtained by driving the light emitting unit 8 only in the past are achieved. It becomes possible to respond. 6 and 7, the image of the light distribution characteristic in each of the wide-angle illumination and the narrow-angle illumination will be described in more detail.

  FIG. 6 is a light distribution characteristic diagram showing light distribution characteristics during wide-angle illumination, and FIG. 7 is a light distribution characteristic diagram showing light distribution characteristics during narrow-angle illumination. 6 and 7, the light distribution characteristics in the vertical direction, that is, the direction perpendicular to the longitudinal direction of the rod-shaped light source 2 are shown, but the light distribution characteristics in the horizontal direction, that is, the longitudinal direction of the rod-shaped light source 2 are also shown. The actions and effects described below apply similarly.

  Since only the first condenser lens 11 functions during wide-angle irradiation, the first condenser lens 11 is designed so that the required super-wide-angle characteristics can be obtained when the light emitting unit 8 is brought close to the lens. The light distribution characteristics of the first condenser lens 11 at this time are shown in FIG. 6, and the light distribution characteristics shown here substantially coincide with the target required ultra-wide-angle light distribution characteristics.

  At the time of narrow-angle irradiation, the second condenser lens 12 is designed so as to obtain a required ultra-narrow angle characteristic. The light distribution image by only the second condenser lens 12 at this time is as shown by a two-dot chain line in the figure. Here, as described above, since the focal length of the first condenser lens 11 is set to be longer than that of the second condenser lens 12, light distribution by only the first condenser lens 11 is illustrated in FIG. As shown by the solid line, it is difficult to realize a narrow angle as the second condenser lens 12 is used, and the guide number is slightly lower than that of the second condenser lens 12. However, since the first condenser lens 11 is formed of a convex lens and has a narrower angle than when the light emitting unit 8 is separated by being separated, the first condenser lens 11 in FIG. If compared, the angle can be sufficiently narrow. Therefore, it can be said that if the sum of the two-dot chain line and the one-dot chain line in FIG. 7 is taken, the required ultra-small angle light distribution characteristic can be substantially achieved without significantly reducing the guide number.

  In order to achieve the above effect, at least the first condensing lens 11 when the illumination angle of the illumination light by the first condensing lens 11 when the light emitting unit 8 approaches is equal to that when the light emitting unit 8 is separated. In addition, it is an essential requirement that the optical characteristics have a wider angle than the irradiation angle of the illumination light by the second condenser lens 12.

(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIGS. In the figure, components having the same reference numerals as those in FIGS. 1 to 5 indicate components having the same function. The second embodiment is an example in which the configuration of the first condenser lens 11 of the optical member 3 is different from the first embodiment. Other configurations are the same as those of the first embodiment.

  The first condenser lens 11 has a plurality of concentric circular vertices 33 and 34 arranged with a separation distance of about ½ of the longitudinal dimension in the region w defined in FIG. Are divided into a plurality of lens curved surfaces 35, 36 by wall surfaces 37, 38 to form Fresnel lenses 39, 40. The second condenser lens 12 is formed with a Fresnel lens 27 similar to that of the first embodiment.

  The two Fresnel lenses 39 and 40 in the first condenser lens 11 are set to have a longer focal length than the Fresnel lens 27 of the second condenser lens 12. And each Fresnel lens 39,40 is arrange | positioned with the above separation distances in a longitudinal direction, The 1st condensing lens 11 is a role which mainly makes the longitudinal direction light distribution characteristic still a wider angle. Take on.

  According to the above configuration, in addition to the same effects as those in the first embodiment, the light distribution characteristic in the longitudinal direction of the rod-shaped light source 2 that is likely to be a problem when the rod-shaped light source 2 is used is improved during wide-angle illumination. Can do.

  Of course, the present invention is not limited to the above-described embodiments, and can be applied to all uses other than the uses shown below, for example.

  (1) In each of the embodiments described above, the first condenser lens 11 is formed in a region facing the rectangular opening 7 of the light emitting unit 8, but the first condenser lens 11 protrudes from the region w. It may be formed. For example, as shown in FIG. 11A, the region p that forms the first condenser lens 11 may be formed beyond the region w, and as shown in FIG. You may form in the area | region w.

Therefore, for example, as shown in FIG. 12, it is conceivable to form the first condensing lens 11 as shown in the region (inside the chain line in the figure) facing the rectangular opening 7 of the light emitting unit 8. The first condenser lens 11 is composed of Fresnel lenses 19 and 20 and a cylindrical lens 23 as in the first embodiment in terms of optical characteristics, but the outer frame is tracked along the Fresnel lenses 19 and 20. It is formed in a shape. A second condenser lens 12 is formed in a region other than the region of the first condenser lens 11. The second condenser lens 12 has the same optical characteristics as in the first embodiment, but the Fresnel lenses 44 and 45 and the cylindrical lens 46 have an inner circumference that follows the outer shape of the first condenser lens 11. (2) The shape and characteristics of the first condenser lens 11 and the second condenser lens 12 of the optical member 3 can be applied in any form other than the above-described configuration. For example, the first condensing lens 11 and the second condensing lens 12 do not necessarily need to be constituted by Fresnel lenses, and an increase in thickness is allowed, or sufficient optical characteristics can be obtained by thinning the Fresnel lens. If it is difficult, it may be formed as a normal convex lens that is not a Fresnel lens.

  (3) The light emitting unit 8 does not necessarily change the relative position between the reflector 1 and the rod-shaped light source 2, and may fix the relative position between the reflector 1 and the rod-shaped light source 2. . Further, the shape of the reflector 1 is not limited to one having a substantially parabolic cross section in a direction orthogonal to the axial direction of the rod-like light source 2.

  (4) The optical member 3 may be composed of one piece as in the above embodiment, or a plurality of pieces of the optical member 3 are arranged to disperse the first condenser lens 11 and the second condenser lens 12 respectively. The optical power may be dispersed. Further, the optical member 3 may include a diffusion optical system that diffuses optical power from the first condenser lens 11 and the second condenser lens 12 to suppress unevenness of illumination light.

  (5) In FIG. 2, the optical member 3 is divided into the region w and the region t. However, the focal length may gradually decrease from the outer edge of the region w to the outer edge of the optical member 3. . In this case, the relationship between the amount of movement of the light emitting unit 8 and the change of the region irradiated with the light from the rectangular opening in the optical member 3 is determined and quantified.

  INDUSTRIAL APPLICABILITY The present invention is suitable as an optical member corresponding to changing a shooting angle of view, that is, changing an irradiation angle of illumination light in accordance with a change in shooting magnification, a strobe device provided with the optical member, and an image recording device incorporating the strobe device. It is.

DESCRIPTION OF SYMBOLS 1 Reflector 2 Rod-shaped light source 3 Optical member 4 Substantially paraboloid reflecting surface 5 Side reflecting surface 6 Bottom part 7 Rectangular opening 8 Light emission part 11 1st condensing lens 12 2nd condensing lens

Claims (6)

The light emitting unit, which includes a reflector having a reflecting surface connected to the opening and a light source arranged to be displaceable relative to the bottom of the reflector, is disposed so as to be displaceable relative to the opening. Is an optical member that brings the light-emitting part closer compared to the case of narrow-angle illumination,
A first condensing optical system is formed in a region facing the opening, a second condensing optical system is formed in a region other than the region facing the opening, and the first condensing optical system is An optical member, wherein the optical member is a convex lens having a focal length longer than that of the second condensing optical system.   The optical member according to claim 1, wherein the first condensing optical system and / or the second condensing optical system is a Fresnel lens.   It is composed of one or a plurality of translucent members, and the optical powers of the first condensing optical system and / or the second condensing optical system are respectively dispersed on the respective surfaces of the translucent members. The optical member according to claim 1, wherein the optical member is formed.   A diffusion optical system for diffusing the optical power of the first condensing optical system and / or the second condensing optical system is used as the first condensing optical system and / or the second condensing optical system. The optical member according to any one of claims 1 to 3, wherein the optical member is formed so as to overlap all or a part of a region where the film is formed.   A strobe device comprising the optical member according to any one of claims 1 to 4.   An image recording apparatus comprising the strobe device according to claim 5.

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