JP3817423B2 - Illumination device and photographing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an illumination device suitable as a strobe for a photographing apparatus such as a camera.
[0002]
[Prior art]
As a zoom strobe with variable light distribution angle, those shown in FIGS. 41 to 43 are often used.
[0003]
In these drawings, the zoom strobe is composed of the arc tube 1, the reflection plate 19, and the Fresnel lens 20 that emits the luminous flux from the arc tube 1 as illumination light, and the Fresnel lens 20 or the reflection plate 19 and the arc tube 1. Is moved in the direction of the optical axis AXL, and the light distribution angle is changed by changing the distance in the optical axis direction between the Fresnel lens 20, the reflector 19, and the arc tube 1.
[0004]
[Means for Solving the Problems]
However, in the zoom strobe of the type in which the Fresnel lens or the arc tube and the reflecting plate are moved in the optical axis direction as described above, the light emitted directly from the arc tube is collected when the Fresnel lens is separated from the reflecting plate. In particular, there is a problem that the Fresnel lens is particularly large and the entire apparatus is enlarged.
[0005]
Moreover, since it is theoretically impossible to emit both the light directly emitted from the arc tube and the light emitted after being reflected by the reflector as parallel light, it is difficult to sufficiently narrow the light distribution angle. There is also the problem of being.
[0006]
In other words, since the position on the optical axis of the arc tube itself and the position of the light source image formed by the reflector are different, the light emitted directly from the arc tube and reflected no matter where the Fresnel lens is placed on the optical axis. Both of the light reflected by the plate cannot be made parallel at the same time.
[0007]
Therefore, an object of the present invention is to provide a lighting device that is small in size and can obtain a sufficiently narrow light distribution angle.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the illuminating device of the present invention performs one optical action of a condensing action and a diverging action in a direction perpendicular to the longitudinal direction of the light source and the optical axis direction with respect to the light beam from the tubular light source. A first optical action part that exerts a second optical action part that exerts the other optical action; The first and second optical action portions are moved relative to each other in the longitudinal direction of the light source to The illumination light distribution angle is changed by changing the areas where the first and second optical action portions overlap each other in the optical axis direction.
[0009]
For example, when the areas where the first and second optical action portions overlap each other in the optical axis direction are zero (when they do not overlap each other), the light flux passing through the first optical action portion and the second light flux from the light source The light flux passing through the optical action part is separately subjected to the light converging action and the diverging action, and illumination light distribution with a wide light distribution angle and good light distribution can be obtained. In addition, when the areas of the first and second optical action portions that overlap each other in the optical axis direction are large (for example, when the whole overlaps), the light flux from the light source is emitted from the first optical action portion and the second optical action portion. By receiving both the condensing action and the diverging action through both of the action parts, both optical actions are canceled as a result, and a narrow light distribution angle is obtained compared to the case where the overlapping area is zero. .
[0010]
As described above, in the present invention, the first and second optical action units are configured to change the light distribution angle by changing the areas where they overlap each other in the optical axis direction. It is not necessary to move the light source side or the irradiation lens side in the optical axis direction with respect to the other party, and it is possible to reduce the size of the first and second optical action portions corresponding to the irradiation lens and further the size of the entire illumination device. It is.
[0011]
In particular, if the light beam from the light source is converted into a substantially parallel light beam by the parallel conversion optical action part and then guided to the first and second optical action parts, the first and second optical action parts are in the optical axis direction. In FIG. 2, the entire light beams overlap each other so that the illumination light beam can be emitted as a substantially parallel light beam, and a sufficiently narrow light distribution angle can be obtained.
[0012]
In order to change the overlapping area of the first and second optical action portions, these optical action portions are moved relative to each other in the longitudinal direction of the light source so that they do not protrude from the irradiation surface of the illumination device. It is also possible to move the first and second optical action portions relative to each other, and the size reduction of the lighting device is not impaired.
[0013]
In addition, particularly when the first and second optical action portions are constituted by cylindrical lenses having different refractive power signs, the two optical action portions can be moved in the longitudinal direction of the cylindrical lens with the optical action portions being in close contact with each other. This is possible, and can be further reduced in size, and is also advantageous in securing optical performance such as the ability to cancel the condensing action and the diverging action.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
1 to 8 show the configuration and optical action of the illumination device according to the first embodiment of the present invention. Here, the description will be made assuming that the present illumination device is used in a photographing device such as a camera.
[0015]
1 and 2 show a state where the light distribution angle of the illuminating device is narrow, and shows the A section and the B section in FIG. 3 (front view) and FIG. 4 (bottom view) showing the same state, respectively. . 5 and 6 show a state in which the light distribution angle of the lighting device is wide, and shows a C section and a D section in FIG. 7 (front view) and FIG. 8 (bottom view) showing the same state, respectively. .
[0016]
In FIGS. 1, 2, 5, and 6, the light emitted from the arc tube (tubular light source) 1 is directed to the left side of the paper, which is the direction opposite to the subject side, which is the right side of the paper. 2 is reflected back to the arc tube 1 and emitted from the arc tube 1 to the subject side.
[0017]
Of the light beams emitted from the arc tube 1 toward the subject, the light beam emitted above the paper surface is refracted by the incident surface 3C of the prism (optical element) 3 and then is reflected by the total reflection surface (parallel conversion optical action unit) 3TR. The light is totally reflected and becomes a substantially parallel light beam toward the exit surface side of the prism 3.
[0018]
Here, since the light beam emitted from the arc tube 1 to the upper right of the paper is refracted by the incident surface 3C and bent upward, the size of the total reflection surface 3TR of the prism 3 can be reduced.
[0019]
Of the luminous flux emitted from the arc tube 1 toward the subject, the luminous flux emitted downward in the drawing is configured so that the reflecting plate 2 and the prism 3 are vertically symmetrical with respect to the optical axis AXL of the prism 3. The same operation as above is performed.
[0020]
Further, the light near the optical axis AXL out of the light beam emitted from the arc tube 1 toward the subject side is refracted by the cylindrical lens portion (parallel conversion optical action portion) 3R of the prism 3 to become a substantially parallel light beam. Head to the surface side.
[0021]
The reflecting plate 2 covers the portion of the outer peripheral surface of the arc tube 1 on the side opposite to the subject side (illumination light irradiation direction), and the optical axis that does not satisfy the total reflection condition of the total reflection surface 3TR of the prism 3. It is configured to cover nearby parts.
[0022]
The cross section including the optical axis of the total reflection surface 3TR and the outline of the cross section parallel thereto are preferably a parabola or a cylindrical aspheric surface that is substantially close to the parabola in order to keep the parallelism of the emitted light beam good.
[0023]
Further, the cylindrical lens portion 3R of the prism 3 is preferably formed as a hyperboloid in FIG.
[0024]
More specifically, as shown below, when the value of the cone coefficient K is a negative value of the square of the refractive index of the prism 3, the spherical aberration of the cylindrical lens portion 3R of the prism 3 can be reduced to zero.
[0025]
For example, when the refractive index of the prism 3 is 1.5, the cone coefficient is preferably −2.25.
[0026]
《Aspherical shape formula》
X = h ² / R / {1 + √ (1- (1 + K) * (h / R) ² }
Where X is the amount of sag
R: Paraxial radius of curvature
K: Conic coefficient
h: Distance from the optical axis
And
[0027]
In this way, all the light beams emitted from the center of the arc tube 1 are converted into substantially parallel light beams by the parallel conversion optical action of the total reflection surface 3TR (reflecting plate 2) of the prism 3 and the cylindrical lens portion 3R.
[0028]
Then, the light is emitted from the A cross-section portion (the portion where the emission plane portion 3H1 is formed) shown in FIG.
[0029]
On the other hand, in FIG. 2, a plurality of cylindrical lens portions (first optical action portions) 3 </ b> P having convergence with respect to an incident substantially parallel light flux are formed on the exit surface of the B cross section of the prism 3. In the state 2, the lens plate 4 having a cylindrical lens portion (second optical action portion) 4N having a divergence (divergence action) that cancels the refractive power thereof is substantially in contact with the cylindrical lens portion 3P. It is arranged with.
[0030]
In this state, since the convergence of the cylindrical lens unit 3P and the divergence of the cylindrical lens unit 4N cancel each other, the substantially parallel light beam incident on the cylindrical lens unit 3P is almost directly converted into a substantially parallel light beam. To the subject side.
[0031]
Figures 3, 4, 7 and Figure As shown in FIG. 8, the above-described exit plane portion 3H1 and the exit plane portion 3H2 having the same shape as the above-described exit plane portion 3H1 are formed on the lens plate 4 (and the same shape as this). The lens plate 5) is formed in a size overlapping with the lens plate 5). In addition, between the exit plane portions 3H1 and 3H2 on the exit surface of the prism 3, the above-described plurality of cylindrical lens portions 3P are formed so as to overlap the two lens plates 4 and 5.
[0032]
Then, the lens plate 4 is positioned in the left-right direction, that is, light emission, between a position that completely overlaps the left half of the cylindrical lens portion 3P and a position that completely overlaps the exit plane portion 3H1 (a position that does not overlap the cylindrical lens portion 3P). It can slide in the longitudinal direction of the tube 1. Further, the lens plate 5 slides in the left-right direction between a position that completely overlaps the right half of the cylindrical lens portion 3P and a position that completely overlaps the exit plane portion 3H2 (a position that does not overlap the cylindrical lens portion 3P at all). It is movable.
[0033]
Although the slide drive mechanism of the lens plates 4 and 5 will not be described in detail, for example, a mechanical mechanism that slides the lens plates 4 and 5 in conjunction with zooming of the photographing optical system can be employed.
[0034]
3 and 4 (FIGS. 1 and 2), the cylindrical lens portion 4P having convergence and the cylindrical lens portions 4N and 5N having divergence of the lens plates 4 and 5 slid to the center in the horizontal direction of the prism 3 are completely shown. It overlaps with. In this state, as described with reference to FIG. 2, the cylindrical lens portion 3P and the cylindrical lens portions 4N and 5N are in close contact with each other, so that the substantially parallel light beam incident on the cylindrical lens portion 3P is converged and diffused. Also Without doing so, the lens plate 4 remains substantially parallel. (5) Ejected from.
[0035]
On the other hand, in FIG. 1, since the exit plane portion 3H1 (3H2) of the prism 3 originally has neither a converging action nor a diverging action, the light beams incident on these exit plane portions 3H1 (3H2) remain as substantially parallel light fluxes. Injected from 3H1 (3H2).
[0036]
As described above, in the state shown in FIGS. 1 to 4, the light beam emitted from the center of the arc tube 1 is emitted from all the emission surfaces of the illuminating device without spreading in the vertical direction on the paper surface, that is, as a substantially parallel light beam.
[0037]
7 and 8, when the lens plates 4 and 5 are slid to both ends of the prism 3 in the left-right direction, the divergent cylindrical lens portions 4N and 5N are completely placed on the exit plane portions 3H1 and 3H2 of the prism 3. overlapping. In this state, as shown in FIG. 5, the substantially parallel light beam emitted from the emission plane portion 3H1 (3H2) of the prism 3 is diffused in the vertical direction of the drawing sheet by the cylindrical lens portion 4N (5N) having divergence. .
[0038]
On the other hand, in FIG. 6, since the lens plate 4 (5) is retracted from the front of the cylindrical lens portion 3P having the convergence property of the prism 3, the light beam emitted from the cylindrical lens portion 3P is caused by the converging action of the cylindrical lens portion 3P. Once condensed in the vertical direction of the paper, it diffuses.
[0039]
As described above, in the state shown in FIGS. 5 to 8, the light beam emitted from the center of the arc tube 1 is emitted from all the emission surfaces of the illuminating device while spreading in the vertical direction on the paper surface.
[0040]
As described above, in the present embodiment, the lens plates 4 and 5 are moved between the position overlapping the cylindrical lens portion 3P and the position overlapping the exit plane portions 3H1 and 3H2, so that the cylindrical lens portion having convergence is obtained. The overlapping area of 3P and the cylindrical lenses 4N and 5N having divergence (that is, the area of a region in which light emitted from the illuminating device diverges or diffuses) is changed between zero and the maximum, thereby illuminating device It is possible to change the light distribution angle of the emitted light beam from the minimum light distribution angle by the substantially parallel light beam and the maximum light distribution angle by the diffused light beam.
[0041]
Further, when the lens plates 4 and 5 are located at an intermediate position between the positions shown in FIGS. 3 and 4 and the positions shown in FIGS. 7 and 8, the overlapping area of the cylindrical lens portion 3P and the cylindrical lens portions 4N and 5N is illustrated. Since the area of the region in which light beams emitted from all exit surfaces diverge or diffuse in the vertical direction is halved, the vertical light distribution angle is an intermediate value between the minimum and maximum light distribution angles. It becomes. Then, by continuously changing the overlapping area between the cylindrical lens portion 3P and the cylindrical lens portions 4N and 5N from zero to the maximum, the light distribution angle is also continuously changed between the minimum and the maximum. Can do.
[0042]
Thereby, when the photographing optical system is a zoom optical system, an optimal illumination light distribution angle corresponding to the change in the focal length can be obtained.
[0043]
(Second Embodiment)
9 to 16 show the configuration and optical action of the illumination device according to the second embodiment of the present invention. 9 and 10 show a state where the light distribution angle of the illumination device is narrow, and shows an E section and an F section in FIG. 11 (front view) and FIG. 12 (bottom view) showing the same state, respectively. . Further, FIGS. 13 and 14 show a state where the light distribution angle of the lighting device is wide, and shows a G section and an H section in FIGS. 15 (front view) and FIG. 16 (bottom view) showing the same state, respectively. .
[0044]
The illuminating device of this embodiment has substantially the same configuration as the illuminating device of the first embodiment, but the position of the cylindrical lens portion 6P in the prism 6 used in place of the prism 3 of the first embodiment is different.
[0045]
9, 10, 13, and 14, of the light beam emitted from the arc tube (tubular light source) 1, the light traveling toward the left side of the paper, which is the direction opposite to the subject side on the right side of the paper, is a semi-cylindrical reflector. 2 is reflected back to the arc tube 1 and emitted from the arc tube 1 to the subject side.
[0046]
Of the light beams emitted from the arc tube 1 toward the subject, the light beam emitted above the plane of the drawing is refracted by the incident surface 6C of the prism (optical element) 6 and then reflected by the total reflection surface (parallel conversion optical action unit) 6TR. It is totally reflected and travels toward the exit surface side of the prism 6 as a substantially parallel light beam.
[0047]
Here, since the light beam emitted from the arc tube 1 to the upper right of the paper is refracted by the incident surface 6C and bent upward, the size of the total reflection surface 6TR of the prism 6 can be reduced.
[0048]
Of the light beams emitted from the arc tube 1 toward the subject, the light beams emitted downward in the drawing are configured so that the reflector 2 and the prism 6 are vertically symmetrical with respect to the optical axis AXL of the prism 6. The same operation as above is performed.
[0049]
Further, the light in the vicinity of the optical axis AXL out of the light flux emitted from the arc tube 1 toward the subject side is refracted by the cylindrical lens portion (parallel conversion optical action portion) 6R of the prism 6 to become a substantially parallel light flux. Head to the surface side.
[0050]
The reflector 2 covers a portion of the outer peripheral surface of the arc tube 1 on the side opposite to the subject side (illumination light irradiation direction), and an optical axis that does not satisfy the total reflection condition of the total reflection surface 6TR of the prism 6. It is configured to cover nearby parts.
[0051]
In FIGS. 9, 10, 13, and 14, the shape of the total reflection surface 6TR is preferably a parabola or a cylindrical aspheric surface that is substantially close to a parabola in order to keep the parallelism of the emitted light beam good.
[0052]
The cylindrical lens portion 6R of the prism 6 is preferably formed as a hyperboloid in FIGS. 9, 10, 13, and 14 as in the first embodiment.
[0053]
In this way, all the light beams emitted from the center of the arc tube 1 are converted into substantially parallel light beams by the parallel conversion optical action of the total reflection surface 6TR (reflecting plate 2) of the prism 6 and the cylindrical lens portion 6R.
[0054]
Then, the light is emitted from the F cross-section portion (the portion where the emission flat surface portion 6H is formed) shown in FIG.
[0055]
In FIG. 9, a plurality of cylindrical lens portions (first optical action portions) 6P having a convergence property with respect to an incident substantially parallel light flux are formed on the exit surface of the E section of the prism 6 as shown in FIG. In the state, the lens plate 7 having a cylindrical lens portion (second optical action portion) 7N having a divergence (divergence action) that cancels the refractive power is opposed to the cylindrical lens portion 6P and is almost in close contact with the cylindrical lens portion 6P. Is done.
[0056]
In this state, the convergence of the cylindrical lens portion 6P and the divergence of the cylindrical lens portion 7N cancel each other, so that the substantially parallel light beam incident on the cylindrical lens portion 6P is almost directly converted into a substantially parallel light beam. To the subject side.
[0057]
As shown in FIGS. 11, 12, 15, and 16, the exit plane portion 6 </ b> H described above is formed in the middle portion of the exit surface of the prism 6 in the horizontal direction of the paper so that the two lens plates 7 and 8 overlap each other. Yes. In addition, the plurality of cylindrical lens portions 6P described above are formed in a size overlapping with the lens plates 7 and 8 at the peripheral portions on both sides in the left-right direction of the drawing surface of the prism 6.
[0058]
The lens plate 7 is moved in the left-right direction between a position that completely overlaps the left cylindrical lens portion 6P and a position that completely overlaps the left half of the emission plane portion 6H (a position that does not overlap the cylindrical lens portion 6P at all). That is, sliding movement is possible in the longitudinal direction of the arc tube 1. Further, the lens plate 8 is moved in the left-right direction between a position that completely overlaps the right cylindrical lens portion 6P and a position that completely overlaps the right half of the emission plane portion 6H (a position that does not overlap the cylindrical lens portion 6P at all). The slide movement is possible.
[0059]
Although the slide drive mechanism of the lens plates 7 and 8 will not be described in detail, for example, a mechanical mechanism that slides the lens plates 7 and 8 in conjunction with zooming of the photographing optical system can be employed.
[0060]
11 and 12 (FIGS. 9 and 10), the cylindrical lens portion 6P having convergence and the cylindrical lens portions 7N and 8N having divergence in the lens plates 7 and 8 slid to both ends in the left-right direction of the prism 6 are almost complete. It overlaps with. In this state, as described with reference to FIG. 9, the cylindrical lens portion 6P and the cylindrical lens portions 7N and 8N are almost in close contact with each other, so that the substantially parallel light beam incident on the cylindrical lens portion 6P is converged and diffused. Also Without exiting, the light is emitted from the lens plate 7 (8) with a substantially parallel light beam.
[0061]
On the other hand, in FIG. 10, since the exit plane portion 6H of the prism 6 originally has neither a converging action nor a diverging action, the light beam incident on the exit plane portion 6H exits from the exit plane portion 6H as a substantially parallel beam.
[0062]
As described above, in the state shown in FIGS. 9 to 12, the light beam emitted from the center of the arc tube 1 is emitted from all emission surfaces of the illuminating device without spreading in the vertical direction on the paper surface, that is, as a substantially parallel light beam.
[0063]
In addition, when the lens plates 7 and 8 shown in FIGS. 13 and 14 (FIGS. 15 and 16) are slid to the center side of the prism 6, the cylindrical lens portions 7N and 8N having divergence are the emission plane portion 6H of the prism 6. Is completely overlapping. In this state, as shown in FIG. 14, the substantially parallel light beam emitted from the emission plane portion 6H of the prism 6 is diffused in the vertical direction of the drawing by the cylindrical lens portion 7N (8N) having a divergence.
[0064]
On the other hand, in FIG. 13, since the lens plate 7 (8) is retracted from the front of the cylindrical lens portion 6P having the convergence property of the prism 6, the luminous flux emitted from the cylindrical lens portion 6P is caused by the converging action of the cylindrical lens portion 6P. Once condensed in the vertical direction of the paper, it diffuses.
[0065]
As described above, in the state shown in FIGS. 13 to 16, the light beam emitted from the center of the arc tube 1 is emitted from all the emission surfaces of the illuminating device so as to spread in the vertical direction on the paper surface.
[0066]
As described above, in the present embodiment, the lens plates 7 and 8 are moved between the position overlapping the cylindrical lens portion 6P and the position overlapping the exit plane portion 6H, so that the cylindrical lens portion 6P having convergence is obtained. The overlapping area (that is, the area of the region in which the light emitted from the illuminating device diverges or diffuses) with the divergent cylindrical lens portions 7N and 8N is changed between zero and the maximum. The light distribution angle of the emitted light beam can be changed to the minimum light distribution angle by the substantially parallel light beam and the maximum light distribution angle by the diffused light beam.
[0067]
Further, when the lens plates 7 and 8 are at an intermediate position between the positions shown in FIGS. 11 and 12 and the positions shown in FIGS. 15 and 16, the overlapping area of the cylindrical lens portion 6P and the cylindrical lens portions 7N and 8N is illustrated. 11 and 12, and the area of the region in which the light beams emitted from all the exit surfaces diverge or diffuse in the vertical direction are halved. Therefore, the vertical light distribution angle is an intermediate value between the minimum and maximum light distribution angles. It becomes. Then, by continuously changing the overlapping area between the cylindrical lens portion 6P and the cylindrical lens portions 7N and 8N from zero to the maximum, the light distribution angle is also continuously changed between the minimum and the maximum. Can do.
[0068]
Thereby, when the photographing optical system is a zoom optical system, an optimal illumination light distribution angle corresponding to the change in the focal length can be obtained.
[0069]
Here, when this embodiment is compared with the first embodiment, when the light distribution angle shown in FIGS. 9 to 12 is narrow, the central portion of the prism 6 having a larger amount of emitted light than the peripheral portion has the lens plates 7, 8. Therefore, the loss of light amount due to the surface reflection of the lens plates 7 and 8 is reduced, the total amount of light emitted is increased, and the guide number can be increased.
[0070]
(Third embodiment)
17 to 24 show the configuration and optical action of the illumination device according to the third embodiment of the present invention. FIGS. 17 and 18 show a state where the light distribution angle of the illumination device is narrow, and shows a J section and a K section in FIGS. 19 (front view) and FIG. 20 (bottom view) showing the same state, respectively. . 21 and 22 show a state in which the illumination device has a wide light distribution angle, and shows an L section and an M section in FIG. 23 (front view) and FIG. 24 (bottom view) showing the same state, respectively. .
[0071]
The illuminating device of this embodiment basically has the same principle as that of the illuminating devices of the first and second embodiments, but the cylindrical in the prism 9 used in place of the prisms 3 and 6 of the first and second embodiments. The position and size of the lens portion 9P and the number of lens plates 10 to be used are different.
[0072]
17, 18, 21, and 22, of the luminous flux emitted from the arc tube (tubular light source) 1, the light traveling toward the left side of the paper, which is the direction opposite to the subject side that is the right side of the paper, is a semi-cylindrical reflector. 2 is reflected back to the arc tube 1 and emitted from the arc tube 1 to the subject side.
[0073]
Of the light beams emitted from the arc tube 1 toward the subject, the light beam emitted above the plane of the drawing is refracted by the incident surface 9C of the prism (optical element) 9 and then reflected by the total reflection surface (parallel conversion optical action unit) 9TR. It is totally reflected and travels toward the exit surface side of the prism 9 as a substantially parallel light beam.
[0074]
Here, the light beam emitted from the arc tube 1 to the upper right side of the drawing is bent upward by being refracted by the incident surface 9C, so that the size of the total reflection surface 9TR of the prism 9 can be reduced.
[0075]
Of the light beams emitted from the arc tube 1 toward the subject, the light beam emitted downward in the drawing is configured so that the reflector 2 and the prism 9 are vertically symmetrical with respect to the optical axis AXL of the prism 9. The same operation as above is performed.
[0076]
Further, the light near the optical axis AXL out of the light beam emitted from the arc tube 1 toward the subject side is refracted by the cylindrical lens portion (parallel conversion optical action portion) 9R of the prism 9 to become a substantially parallel light beam. Head to the surface side.
[0077]
The reflector 2 covers a portion of the outer peripheral surface of the arc tube 1 on the side opposite to the subject side (illumination light irradiation direction), and an optical axis that does not satisfy the total reflection condition of the total reflection surface 9TR of the prism 9. It is configured to cover nearby parts.
[0078]
The shape of the total reflection surface 9TR is preferably a parabola or a cylindrical aspherical surface substantially similar to the parabola in FIGS. 17, 18, 21, and 22 in order to keep the parallelism of the emitted light beam good.
[0079]
The cylindrical lens portion 9R of the prism 9 is preferably formed as a hyperboloid in FIGS. 17, 18, 21, and 22 as in the first embodiment.
[0080]
In this way, all the light beams emitted from the center of the arc tube 1 are converted into substantially parallel light beams by the parallel conversion optical action of the total reflection surface 9TR (reflecting plate 2) of the prism 9 and the cylindrical lens portion 9R.
[0081]
Then, the light is emitted from the K cross-section portion (the portion where the emission plane portion 9H is formed) shown in FIG.
[0082]
In FIG. 17, a plurality of cylindrical lens portions (first optical action portions) 9 </ b> P having convergence with respect to an incident substantially parallel light flux are formed on the exit surface of the J cross section of the prism 9. In the state, the lens plate 10 having a cylindrical lens portion (second optical action portion) 10N having a divergence (divergence action) that cancels the refractive power is opposed to the cylindrical lens portion 9P and is arranged in a substantially intimate contact state. Is done.
[0083]
In this state, the convergence of the cylindrical lens portion 9P and the divergence of the cylindrical lens portion 10N cancel each other, so that the substantially parallel light beam incident on the cylindrical lens portion 9P is almost directly converted into a substantially parallel light beam. To the subject side.
[0084]
As shown in FIGS. 19, 20, 23, and 24, the above-described plurality of cylindrical lens portions 9 </ b> P are formed on the left half of the exit surface of the prism 9 so as to overlap the lens plate 10. In addition, on the right half of the exit surface of the prism 9, the above-described exit plane portion 9 </ b> H is formed so as to overlap the lens plate 10.
[0085]
The lens plate 10 is positioned in the left-right direction, that is, the position of the arc tube 1 between the position that completely overlaps the cylindrical lens portion 9P and the position that completely overlaps the emission plane portion 10H (the position that does not overlap at all with the cylindrical lens portion 9P). It is slidable in the longitudinal direction.
[0086]
Although the slide drive mechanism of the lens plate 10 will not be described in detail, for example, a mechanical mechanism that slides the lens plate 10 in conjunction with zooming of the photographing optical system can be employed.
[0087]
19 and 20 (FIGS. 17 and 18), the cylindrical lens portion 9P having convergence and the cylindrical lens portion 10N having divergence in the lens plate 10 slid to the left end of the prism 9 are almost completely overlapped. In this state, as described with reference to FIG. 17, the cylindrical lens portion 9P and the cylindrical lens portion 10N are substantially in close contact with each other, so that the substantially parallel light beam incident on the cylindrical lens portion 9P converges and diffuses. Also Without exiting, the light is emitted from the lens plate 10 with a substantially parallel light beam.
[0088]
On the other hand, in FIG. 18, since the exit plane portion 9H of the prism 9 originally has neither a converging action nor a diverging action, the light beam incident on the exit plane portion 9H exits from the exit plane portion 9H as a substantially parallel light beam.
[0089]
As described above, in the state shown in FIGS. 17 to 20, the light beam emitted from the center of the arc tube 1 is emitted from all emission surfaces of the illuminating device without spreading in the vertical direction on the paper surface, that is, as a substantially parallel light beam.
[0090]
Further, when the lens plate 10 shown in FIGS. 23 and 24 (FIGS. 21 and 22) is slid to the right end of the prism 9, the cylindrical lens portion 10 </ b> N having divergence completely overlaps with the emission plane portion 9 </ b> H of the prism 9. ing. In this state, as shown in FIG. 22, the substantially parallel light beam emitted from the emission plane portion 9H of the prism 9 is diffused in the vertical direction of the drawing by the cylindrical lens portion 10N having divergence.
[0091]
On the other hand, in FIG. 21, since the lens plate 10 is retracted from the front of the cylindrical lens portion 9P having the converging property of the prism 9, the light beam emitted from the cylindrical lens portion 9P is vertically moved by the cylindrical lens portion 9P. Once condensed, the light diffuses.
[0092]
As described above, in the state shown in FIGS. 21 to 24, the light beam emitted from the center of the arc tube 1 is emitted from all the emission surfaces of the illuminating device so as to spread in the vertical direction on the paper surface.
[0093]
As described above, in the present embodiment, the lens plate 10 is moved between the position overlapping the cylindrical lens portion 9P and the position overlapping the exit plane portion 9H, so that the convergent cylindrical lens portion 9P and the divergence are obtained. The area overlapping with the cylindrical lens portion 10N having the above (that is, the area of the region in which light emitted from the illuminating device diverges or diffuses) is changed between zero and the maximum, thereby distributing the emitted light from the illuminating device. The light angle can be changed between a minimum light distribution angle by a substantially parallel light beam and a maximum light distribution angle by a diffuse light beam.
[0094]
Further, when the lens plate 10 is at an intermediate position between the positions shown in FIGS. 19 and 20 and the positions shown in FIGS. 23 and 24, the overlapping area of the cylindrical lens portion 9P and the cylindrical lens portion 10N is as shown in FIGS. Since the area of the region in which the light beam emitted from all emission surfaces diverges or diffuses in the vertical direction is halved, the vertical light distribution angle is an intermediate value between the minimum and maximum light distribution angles. Then, by continuously changing the overlapping area of the cylindrical lens portion 9P and the cylindrical lens portion 10N from zero to the maximum, the light distribution angle can also be continuously changed between the minimum and the maximum. .
[0095]
Thereby, when the photographing optical system is a zoom optical system, an optimal illumination light distribution angle corresponding to the change in the focal length can be obtained.
[0096]
Here, comparing this embodiment with the first and second embodiments, in this embodiment, the number of parts is reduced because the lens plate 10 having a plurality of cylindrical lens portions 10N having divergence is one. Cost can be reduced. Further, since only one lens plate 10 needs to be slid, the configuration of the lens plate slide drive mechanism is simpler than the first and second embodiments in which the two lens plates are slid in opposite directions. Can be.
[0097]
(Fourth embodiment)
25 to 32 show the configuration and optical action of the illumination device according to the fourth embodiment of the present invention. 25 and 26 show a state where the light distribution angle of the illumination device is narrow, and shows an N cross section and a Q cross section in FIG. 27 (front view) and FIG. 28 (bottom view) showing the same state, respectively. . Further, FIGS. 29 and 30 show a state where the light distribution angle of the illuminating device is wide, and show an R section and an S section in FIG. 31 (front view) and FIG. 32 (bottom view) showing the same state, respectively. .
[0098]
The illumination device of the present embodiment uses the same principle as the illumination devices of the first and second embodiments, but the cylindrical lens portions 11P, 11PL, and 11PR in the prism 11 used in place of the prism 3 of the first embodiment. And the number of lens plates 12 to 15 used are different.
[0099]
In FIGS. 25, 26, 29, and 30, of the light emitted from the arc tube (tubular light source) 1, the light traveling toward the left side of the paper, which is the direction opposite to the subject side that is the right side of the paper, is a semi-cylindrical reflector. 2 is reflected back to the arc tube 1 and emitted from the arc tube 1 to the subject side.
[0100]
Of the light beams emitted from the arc tube 1 toward the subject, the light beam emitted above the paper surface is refracted by the incident surface 11C of the prism (optical element) 11 and then is reflected by the total reflection surface (parallel conversion optical action unit) 11TR. The light is totally reflected and travels toward the exit surface of the prism 11 as a substantially parallel light beam.
[0101]
Here, since the light beam emitted from the arc tube 1 to the upper right of the paper is refracted by the incident surface 11C and bent upward, the size of the total reflection surface 11TR of the prism 11 can be reduced.
[0102]
Of the light beams emitted from the arc tube 1 toward the subject, the light beam emitted downward in the drawing is configured so that the reflector 2 and the prism 11 are vertically symmetrical with respect to the optical axis AXL of the prism 11. The same operation as above is performed.
[0103]
The light near the optical axis AXL out of the luminous flux emitted from the arc tube 1 toward the subject side is refracted by the cylindrical lens portion (parallel conversion optical action portion) 11R of the prism 11 to become a substantially parallel luminous flux. Head to the surface side.
[0104]
The reflector 2 covers a portion of the outer peripheral surface of the arc tube 1 on the side opposite to the subject side (irradiation direction of illumination light), and the optical axis that does not satisfy the total reflection condition among the total reflection surface 11TR of the prism 11. It is configured to cover nearby parts.
[0105]
The shape of the total reflection surface 11TR is preferably a parabola or a cylindrical aspherical surface substantially similar to the parabola in FIGS. 25, 26, 29, and 30 in order to keep the parallelism of the emitted light beam good.
[0106]
Further, the cylindrical lens portion 11R of the prism 11 is preferably formed as a hyperboloid in FIGS. 25, 26, 29, and 30 as in the first embodiment.
[0107]
In this way, all the light beams emitted from the center of the arc tube 1 are converted into substantially parallel light beams by the parallel conversion optical action of the total reflection surface 11TR (reflecting plate 2) of the prism 11 and the cylindrical lens portion 11R.
[0108]
Then, the light is emitted from the N cross-section portion (the portion where the emission flat surface portion 11H2 is formed) shown in FIG.
[0109]
In FIG. 26, a plurality of cylindrical lens portions (first optical action portions) 11 </ b> P having convergence with respect to an incident substantially parallel light beam are formed on the exit surface of the Q section of the prism 11. In the state of FIG. 26, these cylindrical lens portions 11P The lens plate 12 having a cylindrical lens portion (second optical action portion) 12N having a divergence (divergence action) that cancels the refractive power is disposed in a state of being in close contact with each other.
[0110]
In this state, since the convergence of the cylindrical lens portion 11P and the divergence of the cylindrical lens portion 12N cancel each other, the substantially parallel light beam incident on the cylindrical lens portion 11P is almost directly converted into a substantially parallel light beam. To the subject side.
[0111]
As shown in FIGS. 27, 28, 31, and 32, emission plane portions 11H1 to 11H4 are provided on the prism end side of the peripheral portion on both sides in the left-right direction of the paper surface on the exit surface of the prism 11 and the prism end side of the intermediate portion in the left-right direction. The four lens plates 12 to 15 are formed so as to overlap each other. Further, the plurality of cylindrical lens portions 11P described above are formed in a size overlapping the two lens plates 12 and 14 at the intermediate portion in the left-right direction on the exit surface of the prism 11.
[0112]
Further, a plurality of cylindrical lens portions 11PL and 11PR having convergence are formed on the remaining left and right portions of the exit surface of the prism 11 so as to overlap the lens plates 13 and 15, respectively.
[0113]
And each lens plate 12-15 is each cylindrical lens part 11P, 11. PL , 11 PR Between the position that completely overlaps with the emission plane portions 11H1 to 11H2 (the position that does not overlap with the cylindrical lens portions 11P, 11PL, and 11PR at all) and slides in the left-right direction, that is, the longitudinal direction of the arc tube 1 It is possible.
[0114]
Although the slide drive mechanism of the lens plates 12 to 15 will not be described in detail, for example, the lens plate is interlocked with zooming of the photographing optical system. 12-15 It is possible to adopt a mechanical mechanism that slides.
[0115]
27 and 28 (FIGS. 25 and 26), the cylindrical lens portions 11P, 11PL, and 11PR having convergence and the cylindrical lens portions 12N to 15N having divergence in the lens plates 12 to 15 are almost completely overlapped with each other. In this state, as described with reference to FIG. 26, the cylindrical lens portion 11P (11PL, 11PR) and the cylindrical lens portions 12N to 15N are substantially in close contact with each other, and therefore enter the cylindrical lens portion 11P (11PL, 11PR). The almost parallel light flux converged and diffused Also Without using the lens plate 12, 14 (13, 15) Ejected from.
[0116]
On the other hand, in FIG. 11 Injection plane part 11H2 Since there is no converging action or diverging action, the light beam incident on the emission plane part 11P (11PL, 11PR) is emitted from the emission plane part 11H2 (11H1, 11H3, 11H4) as a substantially parallel light beam.
[0117]
As described above, in the state shown in FIGS. 25 to 28, the light beam emitted from the center of the arc tube 1 is emitted from all the emission surfaces of the illuminating device without spreading in the vertical direction on the paper surface, that is, as a substantially parallel light beam.
[0118]
31 and 32 (FIGS. 29 and 30), the cylindrical lens portions 12N to 15N having the divergence of the lens plates 12 to 15 completely overlap the exit plane portions 11H1 to 11H4 of the prism 11. . In this state, as shown in FIG. 29, the substantially parallel light beam emitted from the emission plane portion 11H2 (11H1, 11H3, 11H4) of the prism 11 is a cylindrical lens having the divergence of the lens plate 12 (13-15). It is diffused in the vertical direction on the paper surface by the section 12N (13N to 15N).
[0119]
On the other hand, in FIG. 30, since the lens plate 12 (13, 14, 15) is retracted from the front of the cylindrical lens portion 11P (11PL, 11PR) having the convergence of the prism 11, the cylindrical lens portion 11P (11PL, 11PR) is retracted. ) Is once condensed in the vertical direction on the paper surface by the converging action of the cylindrical lens portion 11P (11PL, 11PR) and then diffused.
[0120]
As described above, in the state shown in FIGS. 25 to 28, the light beam emitted from the center of the arc tube 1 is emitted from all the emission surfaces of the illuminating device so as to spread in the vertical direction on the paper surface.
[0121]
As described above, in the present embodiment, the lens plates 12 to 15 are moved between the positions overlapping the cylindrical lens portions 11P, 11PL, and 11PR and the positions overlapping the exit plane portions 11H1 and 11H4, thereby achieving convergence. The overlapping area of the cylindrical lens portions 11P, 11PL, 11PR having the divergence and the cylindrical lens portions 12N to 15N having divergence (that is, the area of the region in which the light emitted from the illumination device diverges or diffuses) is between zero and maximum. Thus, the light distribution angle of the light beam emitted from the illumination device can be changed to the minimum light distribution angle by the substantially parallel light beam and the maximum light distribution angle by the diffused light beam.
[0122]
Further, when the lens plates 12 to 15 are at an intermediate position between the positions shown in FIGS. 27 and 28 and the positions shown in FIGS. 31 and 32, the cylindrical lens portions 11P, 11PL, and 11PR and the cylindrical lens portions 12N to 15N are located. The overlapping area is half that of FIGS. 27 and 28, and the area of the region in which the light beam emitted from all emission surfaces diverges or diffuses in the vertical direction is halved. Therefore, the vertical light distribution angle is the minimum and maximum light distribution angles. The intermediate value of. Then, by continuously changing the overlapping area of the cylindrical lens portions 11P, 11PL, and 11PR and the cylindrical lens portions 12N to 15N from zero to the maximum, the light distribution angle is continuously between the minimum and the maximum. Can be changed.
[0123]
Thereby, when the photographing optical system is a zoom optical system, an optimal illumination light distribution angle corresponding to the change in the focal length can be obtained.
[0124]
Here, when this embodiment is compared with the first and second embodiments, since the lens plates 12 to 15 are divided into four, the lens plate is compared with the first and second embodiments where the lens plate is divided into two. The amount of movement can be reduced, and the slide drive mechanism can be reduced in size.
[0125]
(Fifth embodiment)
33 to 40 show the configuration and optical action of the fifth embodiment of the present invention. 33 and 34 show a state where the light distribution angle of the illumination device is narrow, and shows a T section and a V section in FIG. 35 (front view) and FIG. 36 (bottom view) showing the same state, respectively. . Further, FIGS. 37 and 38 show a state where the light distribution angle of the lighting device is wide, and show a W cross section and an X cross section in FIG. 39 (front view) and FIG. 40 (bottom view) showing the same state, respectively. .
[0126]
In FIGS. 33, 34, 37, and 38, the light emitted from the arc tube (tubular light source) 1 is directed toward the left side of the paper, which is the direction opposite to the subject side on the right side of the paper, and is a semi-cylindrical reflector. 2 is reflected back to the arc tube 1 and emitted from the arc tube 1 to the subject side.
[0127]
Of the light beams emitted from the arc tube 1 toward the subject, the light beam emitted above the plane of the drawing is refracted by the incident surface 16C of the prism (optical element) 16 and then reflected by the total reflection surface (parallel conversion optical action unit) 16TR. The light is totally reflected and travels toward the exit surface side of the prism 16 as a substantially parallel light beam.
[0128]
Here, since the light beam emitted from the arc tube 1 to the upper right of the paper is refracted by the incident surface 16C and bent upward, the size of the total reflection surface 16TR of the prism 16 can be reduced.
[0129]
Of the light beams emitted from the arc tube 1 toward the subject, the light beam emitted downward in the drawing is configured so that the reflector 2 and the prism 16 are vertically symmetrical with respect to the optical axis AXL of the prism 16. The same operation as above is performed.
[0130]
Of the light beam emitted from the arc tube 1 toward the subject, the light in the vicinity of the optical axis AXL is refracted by the cylindrical lens portion (parallel conversion optical action portion) 16R of the prism 16 to become a substantially parallel light beam. Head to the surface side.
[0131]
The reflecting plate 2 covers the portion of the outer peripheral surface of the arc tube 1 opposite to the subject side (illumination light irradiation direction), and the optical axis that does not satisfy the total reflection condition among the total reflection surface 16TR of the prism 16. It is configured to cover nearby parts.
[0132]
33, 34, 37, and 38, the shape of the total reflection surface 16TR is preferably a parabola or a cylindrical aspheric surface that is almost similar to a parabola in order to keep the parallelism of the emitted light beam good.
[0133]
The cylindrical lens portion 16R of the prism 16 is preferably formed as a hyperboloid in FIGS. 33, 34, 37, and 38, as in the first embodiment.
[0134]
In this way, all the light beams emitted from the center of the arc tube 1 are converted into substantially parallel light beams by the parallel conversion optical action of the total reflection surface 16TR (reflecting plate 2) of the prism 16 and the cylindrical lens portion 16R.
[0135]
Then, the light is emitted as it is from the T cross-section portion (the portion where the emission plane portion 16H1 is formed) shown in FIG.
[0136]
In FIG. 34, a convex cylindrical lens portion (first optical action portion) 16P having a convergence property with respect to an incident substantially parallel light flux is formed on the exit surface of the J cross section of the prism 9, and the state shown in FIG. Then, a lens plate 17 having a concave cylindrical lens part (second optical action part) 17N having a divergence (divergence action) that cancels the refractive power is opposed to the convex cylindrical lens part 16P in a substantially contacted state. Be placed.
[0137]
In this state, since the convergence of the convex cylindrical lens portion 16P and the divergence of the concave cylindrical lens portion 16N cancel each other, the substantially parallel light beam incident on the convex cylindrical lens portion 16P is almost directly converted into a substantially parallel light beam. The light is emitted from the lens plate 17 toward the subject.
[0138]
As shown in FIGS. 35, 36, 39, and 40, the above-described exit plane portion 16H1 and exit plane portion 16H2 are the same as the lens plate 17 and the same at the peripheral portions of the exit surface of the prism 16 on both ends in the left-right direction. Each lens plate 18 is formed in a size that overlaps the lens plate 18 formed in a shape. In addition, the convex cylindrical lens portion 16P described above is formed between the two peripheral portions on the exit surface of the prism 16 so as to overlap the two lens plates 17 and 18.
[0139]
The lens plate 17 is positioned in the left-right direction, that is, the arc tube, between a position that completely overlaps the convex cylindrical lens portion 16P and a position that completely overlaps the exit plane portion 16H (a position that does not overlap at all with the convex cylindrical lens portion 16P). 1 is slidable in the longitudinal direction.
[0140]
Although the slide drive mechanism of the lens plates 17 and 18 will not be described in detail, for example, a mechanical mechanism that slides the lens plates 17 and 18 in conjunction with zooming of the photographing optical system can be employed.
[0141]
35 and 36 (FIGS. 33 and 34), the convex cylindrical lens portion 16P having convergence and the concave cylindrical lens portions 17N and 18N having divergence in the lens plates 17 and 18 slid toward the center of the prism 16 are completely formed. It overlaps with. In this state, the convex cylindrical lens portion 16P and the concave cylindrical lens portions 17N and 18N overlap with each other in an almost intimate contact state, so that the substantially parallel light beam incident on the convex cylindrical lens portion 16P is converged and diffused. Also Without exiting, the light is emitted from the lens plate 17 (18) with a substantially parallel light beam.
[0142]
On the other hand, in FIG. 33, the exit plane portion 16H of the prism 16 originally has neither a converging action nor a diverging action, so that the light beam incident on the exit plane portion 16H exits from the exit plane portion 16H as a substantially parallel beam.
[0143]
Thus, in the state shown in FIGS. 33 to 36, the light beam emitted from the center of the arc tube 1 is emitted from all the emission surfaces of the illuminating device without spreading in the vertical direction on the paper surface, that is, as a substantially parallel light beam.
[0144]
In addition, when the lens plates 17 and 18 shown in FIGS. 39 and 40 (FIGS. 37 and 38) slide to the left and right ends of the prism 16, the divergent concave cylindrical lens portions 17N and 18N are the exit plane portions of the prism 16. It completely overlaps 16H1 and 16H2. In this state, as shown in FIG. 37, the substantially parallel light beam emitted from the emission plane portion 16H1 (16H2) of the prism 16 is diffused in the vertical direction of the drawing sheet by the concave cylindrical lens portion 17N (18N) having divergence. The
[0145]
On the other hand, in FIG. 38, since the lens plates 17 and 18 are retracted from the front of the convex cylindrical lens portion 16P having the convergence property of the prism 16, the light beam emitted from the convex cylindrical lens portion 16P is converged by the convex cylindrical lens portion 16P. The light is once condensed in the vertical direction by the action and then diffused.
[0146]
As described above, in the state shown in FIGS. 37 to 40, the light beam emitted from the center of the arc tube 1 spreads out from all the emission surfaces of the illumination device in the vertical direction on the paper surface.
[0147]
As described above, in this embodiment, the lens plates 17 and 18 are moved between a position overlapping the convex cylindrical lens portion 16P and a position overlapping the exit plane portions 16H1 and 16H2, thereby providing a convex cylindrical lens having convergence. The overlapping area of the lens portion 16P and the divergent concave cylindrical lens portions 17N and 18N (that is, the area of the region in which the light emitted from the illumination device diverges or diffuses) is changed between zero and maximum, Thus, the light distribution angle of the light beam emitted from the illumination device can be changed to the minimum light distribution angle by the substantially parallel light beam and the maximum light distribution angle by the diffused light beam.
[0148]
In addition, when the lens plates 17 and 18 are at an intermediate position between the positions shown in FIGS. 35 and 36 and the positions shown in FIGS. 39 and 40, the convex cylindrical lens portion 16P and the concave cylindrical lens portion. 17N , 18N is half that of FIGS. 35 and 36, and the area of the region in which the emitted light beam diverges or diffuses in the vertical direction is halved in all the emission surfaces. It is an intermediate value of the maximum light distribution angle. Then, by continuously changing the overlapping area of the convex cylindrical lens portion 16P and the concave cylindrical lens portions 17N and 18N from zero to the maximum, the light distribution angle also continuously changes between the minimum and the maximum. Can be made.
[0149]
Thereby, when the photographing optical system is a zoom optical system, an optimal illumination light distribution angle corresponding to the change in the focal length can be obtained.
[0150]
Here, in comparison with the present embodiment and the first to fourth embodiments, in this embodiment, the cylindrical lens portions 16P, 17N, and 18N are simpler than the first to fourth embodiments, so that it is easy to make. There are advantages.
[0151]
In each of the above embodiments, the case where the cylindrical lens portion having the convergence or the divergence is formed on the prism and the lens plate has been described, but in order to reduce the thickness, the cylindrical Fresnel lens portion is replaced with the cylindrical lens portion. It may be configured.
[0152]
In each of the above-described embodiments, the case where the cylindrical lens portion having convergence is formed on the prism and the lens plate on which the cylindrical lens portion having divergence is moved is described. However, the cylindrical lens portion having divergence is described. May be formed on the prism, and the lens plate on which the cylindrical lens portion having the convergence property is formed may be movable.
[0153]
Further, in each of the above embodiments, the prism and the lens plate are preferably made of a transparent resin such as acrylic having a good visible light transmittance or a glass mold, but may be made of other materials.
[0154]
In each of the above embodiments, the case where a narrow light distribution angle is obtained by emitting an illumination light beam converted into a substantially parallel light beam by a prism as it is has been described, but the present invention is not limited to this. For example, the light incident on the first optical action portion of the prism from the light source may be a diffused light flux, and may be made into a substantially parallel light flux by the light collecting action of the first optical action portion to obtain a narrow light distribution angle. .
[0155]
In each of the above embodiments, the illumination device (strobe device) used for the camera In As described above, the present invention is considered to be applicable to a wide range of applications, such as an indoor lighting device capable of changing the illumination range and a communication device using flash light, as an illumination device having a variable illumination light irradiation range.
[0156]
Further, in all the embodiments of the present invention described so far, in order to obtain a sufficient light distribution change, parallel light is incident on the first optical action unit and the second optical action unit. It is preferable to determine the shapes of the first optical action part and the second optical action part so that the maximum deflection angle of the first optical action part is 10 degrees or more.
[0157]
More preferably, the shapes of the first optical action part and the second optical action part are determined so that the maximum deflection angle is 15 degrees or more.
[0158]
【The invention's effect】
As described above, according to the present invention, the first optical action part having one of the condensing action and the diverging action and the second optical action part having the other change the overlapping area in the optical axis direction. Therefore, it is not necessary to move the light source side or the irradiation lens side in the optical axis direction with respect to the other party in order to change the light distribution angle, and the first corresponding to the irradiation lens. Further, it is possible to reduce the size of the second optical action unit and further reduce the size of the entire lighting device.
[0159]
In particular, if the light beam from the light source is converted into a substantially parallel light beam by the parallel conversion optical action part and then guided to the first and second optical action parts, the first and second optical action parts are in the optical axis direction. As a result, the illumination light beam can be emitted as a substantially parallel light beam, and a sufficiently narrow light distribution angle can be obtained.
[0160]
Therefore, when the illumination device of the present invention is used as a zoom strobe for a photographing device, a strobe device that is small in size and has a very large guide number when the light distribution angle is narrow can be realized.
[0161]
In order to change the overlapping area of the first and second optical action portions, these optical action portions are moved relative to each other in the longitudinal direction of the light source so that they do not protrude from the irradiation surface of the illumination device. It is also possible to move the first and second optical action portions relative to each other, and the size reduction of the lighting device is not impaired.
[0162]
In addition, particularly when the first and second optical action portions are constituted by cylindrical lenses having different refractive power signs, the two optical action portions can be moved in the longitudinal direction of the cylindrical lens with the optical action portions being in close contact with each other. This is possible, and can be further reduced in size, and is also advantageous in securing optical performance such as the ability to cancel the condensing action and the diverging action.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a lighting device according to a first embodiment of the present invention in a narrow light distribution angle.
FIG. 2 is a cross-sectional view of the lighting device of the first embodiment in a state where a light distribution angle is narrow.
FIG. 3 is a front view showing a state where the light distribution angle of the illumination device of the first embodiment is narrow.
FIG. 4 is a bottom view of the lighting device of the first embodiment in a state where the light distribution angle is narrow.
FIG. 5 is a cross-sectional view of the lighting device according to the first embodiment in a wide light distribution angle state.
6 is a cross-sectional view of the lighting device of the first embodiment in a wide light distribution angle state. FIG.
FIG. 7 is a front view of the lighting device of the first embodiment in a state where the light distribution angle is wide.
FIG. 8 is a bottom view of the lighting device of the first embodiment in a state where the light distribution angle is wide.
FIG. 9 is a cross-sectional view of a lighting device according to a second embodiment of the present invention in a narrow light distribution angle.
FIG. 10 is a cross-sectional view of the lighting device of the second embodiment with a narrow light distribution angle.
FIG. 11 is a front view showing a state where the light distribution angle of the illumination device of the second embodiment is narrow.
FIG. 12 is a bottom view of the lighting device of the second embodiment in a state where the light distribution angle is narrow.
FIG. 13 is a cross-sectional view of the lighting device according to the second embodiment in a wide light distribution angle state.
FIG. 14 is a cross-sectional view of the lighting device of the second embodiment in a state where the light distribution angle is wide.
FIG. 15 is a front view of the illumination device of the second embodiment in a wide light distribution angle state.
FIG. 16 is a bottom view of the lighting device of the second embodiment in a state where the light distribution angle is wide.
FIG. 17 is a cross-sectional view of a lighting device according to a third embodiment of the present invention in a narrow light distribution angle.
FIG. 18 is a cross-sectional view of the lighting device of the third embodiment in a state where the light distribution angle is narrow.
FIG. 19 is a front view showing a state where the light distribution angle of the illumination device of the third embodiment is narrow.
FIG. 20 is a bottom view of the lighting device of the third embodiment with a narrow light distribution angle.
FIG. 21 is a cross-sectional view of the lighting device of the third embodiment with a wide light distribution angle.
FIG. 22 is a cross-sectional view of the illumination device of the third embodiment in a wide light distribution angle state.
FIG. 23 is a front view of the lighting device of the third embodiment in a state where the light distribution angle is wide.
FIG. 24 is a bottom view of the lighting device of the third embodiment with a wide light distribution angle.
FIG. 25 is a cross-sectional view of a lighting device according to a fourth embodiment of the present invention in a narrow light distribution angle.
FIG. 26 is a cross-sectional view of the illumination device of the fourth embodiment in a state where the light distribution angle is narrow.
FIG. 27 is a front view showing a state where the light distribution angle of the illumination device of the fourth embodiment is narrow.
FIG. 28 is a bottom view of the illumination device of the fourth embodiment in a state where the light distribution angle is narrow.
FIG. 29 is a cross-sectional view of the illumination device of the fourth embodiment in a state where the light distribution angle is wide.
FIG. 30 is a cross-sectional view of the illumination device of the fourth embodiment in a state where the light distribution angle is wide.
FIG. 31 is a front view of the illumination device according to the fourth embodiment in a wide light distribution angle state.
FIG. 32 is a bottom view of the illumination device of the fourth embodiment in a state where the light distribution angle is wide.
FIG. 33 is a cross-sectional view of a lighting device according to a fifth embodiment of the present invention in a narrow light distribution angle.
FIG. 34 is a cross-sectional view of the illumination device of the fifth embodiment in a state where the light distribution angle is narrow.
FIG. 35 is a front view showing a state where the light distribution angle of the illumination device of the fifth embodiment is narrow.
FIG. 36 is a bottom view of the lighting device of the fifth embodiment in a state where the light distribution angle is narrow.
FIG. 37 is a cross-sectional view of the illumination device of the fifth embodiment in a state where the light distribution angle is wide.
FIG. 38 is a cross-sectional view of the illumination device of the fifth embodiment in a wide light distribution angle state.
FIG. 39 is a front view of the illumination device of the fifth embodiment in a state where the light distribution angle is wide.
FIG. 40 is a bottom view of the illumination device of the fifth embodiment with a wide light distribution angle.
FIG. 41 is a cross-sectional view of a conventional lighting device in a direction perpendicular to the arc tube.
FIG. 42 is a front view of a conventional lighting device.
FIG. 43 is a cross-sectional view in the longitudinal direction of an arc tube of a conventional lighting device.
[Explanation of symbols]
1 arc tube
2 reflector
3, 6, 9, 11, 16 Prism
4, 5, 7, 8, 10, 12-15, 17, 18 Lens plate
3P, 6P, 9P, 11P, 11PL, 11PR, 16P (convergent) cylindrical lens part
4N, 5N, 7N, 8N, 10N, 12N-15N, 17N, 18N (Divergent) cylindrical lens part
3H1, 3H2, 6H, 9H, 11H to 11H4, 16H Injection plane part

Claims (17)

A first optical action part that exerts one optical action of a light condensing action and a diverging action in a direction perpendicular to the longitudinal direction and the optical axis direction of the light source from the tubular light source, and a second optical action that exerts the other optical action. Two optical working parts,
Changing the illumination angle of light distribution by longitudinally move relative to said first and second optical effects unit alters the area overlap each other in the optical axis direction of the first and second light source optical action section A lighting device characterized in that Said first and second optical action section, in claim 1, characterized in that the relative movement in the longitudinal direction of the light source between a position not overlapping with each other and at least partially overlap positions from each other in the direction of the optical axis The lighting device described. Said first and second optical action section, according to claim 1, characterized in that the relative movement in the longitudinal direction of the light source between a position where a part from each other with each other overlapping positions in the optical axis direction do not overlap Lighting equipment. The other optical action part that moves relative to one of the first and second optical action parts is formed smaller in the longitudinal direction of the light source than the one optical action part, and the other optical action part is formed. the illumination device according to any one of claims 1 to 3, characterized in that moving within between longitudinal ends of the said one of the optical action section. According to any one of claims 1 to 4, characterized in that it has a parallel converting optical action section leading to the first and second optical effects unit and converted into a substantially parallel light flux emitted from the light source Lighting device. Of the first and second optical action parts, an optical action part having a condensing action on which a light beam that has been made into a substantially parallel light beam by the parallel conversion optical action part is incident has a convergence with respect to the substantially parallel light beam. The lighting device according to claim 5 , wherein the lighting device is provided. One of the parallel conversion optical action part and the first and second optical action parts is formed as an integral optical element, and the other optical action part of the first and second optical action parts is: The illumination device according to claim 6 , wherein the illumination device moves in a longitudinal direction of the light source with respect to the first optical action unit. The optical element is prism, this prism, claim and having a reflecting surface as the parallel conversion optical effects unit having a condensing function, and a lens surface of the optical action of the one 7 The lighting device described in 1. Outside the region where the first optical action part and the second optical action part overlap on the exit surface of the optical element, the substantially parallel light beam converted by the parallel conversion optical action part remains as a substantially parallel light beam. the lighting device according to claim 7 or 8, characterized in that a non-optical working part that is emitted. The illumination device according to any one of claims 1 to 9, characterized in that it comprises a reflecting plate covering the opposite side of the portion with the irradiation direction of the illumination light of the outer peripheral surface of the light source. 9. The reflector according to claim 8 , further comprising a reflecting plate that covers at least a portion of the outer peripheral surface of the light source opposite to the illumination light irradiation direction and a portion of the reflecting surface of the prism that does not satisfy the total reflection condition. Lighting equipment. The said 1st optical action part is comprised by the cylindrical lens which has a positive or negative refractive power in the direction orthogonal to the longitudinal direction of the said light source, It is any one of Claim 1 to 11 characterized by the above-mentioned. The lighting device described. The second optical action section is, in a direction perpendicular to the longitudinal direction of the light source positive or to any one of claims 1 to 12, characterized in that is constituted by a cylindrical lens having a negative refractive power The lighting device described. The said 1st optical action part is comprised by the some cylindrical lens which has a positive or negative refractive power in the direction orthogonal to the longitudinal direction of the said light source, The any one of Claim 1 to 11 characterized by the above-mentioned. The lighting device described in one. The said 2nd optical action part is comprised by the some cylindrical lens which has a positive or negative refractive power in the direction orthogonal to the longitudinal direction of the said light source, Either of Claim 1 to 11 and 14 characterized by the above-mentioned. The illuminating device as described in any one. The maximum deflection angle when parallel light is incident on the first optical action unit and the second optical action unit is 10 degrees or more, according to any one of claims 1 to 15 , The lighting device described. An imaging device comprising the illumination device according to any one of claims 1 to 16 .

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