JP4379686B2 - Light control device and imaging device - Google Patents

Description

  The present invention relates to a light control device and an imaging device.

In an imaging apparatus such as a video camera, an imaging signal is detected by forming an object image photographed by a photographing optical system on an imaging element.
Since there is an upper limit to the amount of light that can be detected by the image sensor, a light control device that adjusts the amount of light guided to the image sensor by the imaging optical system so as not to exceed the upper limit is incorporated in the image pickup apparatus.
Conventionally, as such a light control device, one using an iris diaphragm configured so that the aperture can be adjusted, or a combination of an ND filter and an iris diaphragm is used. However, such diffraction deterioration is a problem in improving the performance of the image pickup apparatus.
On the other hand, as a light control device that does not cause such diffraction degradation, a device that adjusts the amount of light using a liquid crystal element has been proposed (see, for example, Patent Document 1).
JP 2002-303850 A

However, since the light amount adjustment range (light transmittance adjustment range) realized by the liquid crystal element is narrower than the light amount adjustment range required in an actual imaging device, such a liquid crystal element was used. The dimmer has not been put into practical use yet.
In addition, with the downsizing of the imaging device, space saving of the light control device and the optical system is required.
The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a light control device and an imaging device that are advantageous in reducing the size of the light amount while expanding the light amount adjustment range.

In order to achieve the above-described object, a light control device according to the present invention is a light control device that adjusts the amount of transmitted light so that the light transmittance can be adjusted stepwise by being positioned on an optical path through which light passes. A first dimming unit configured, a second dimming unit positioned on the optical path, the light transmittance of which is configured to be continuously adjustable, and the light of the first dimming unit Control means for controlling the transmittance and the light transmittance of the second dimming means, wherein the first dimming means includes a neutral density filter having a predetermined optical transmittance, and the neutral density filter. A light-reducing filter moving means for moving to an operating position located on the optical path and a non-operating position retracted from the optical path, and the control of the light transmittance of the first light control means by the control means The neutral density filter moving means moves the neutral density filter to the operating position and the inoperative position. The neutral density filter is composed of a plurality of neutral density filter pieces having different light transmittances τN and arranged in a plane, and is selected from the multiple neutral density filter pieces. When the neutral density filter piece is positioned at the operating position, the remaining neutral density filter segment is configured to be positioned at the non-operative position, the neutral density filter is configured by an ND filter, and the second dimming means. Has a light control element and a light control element driving means for driving the light control element, and the control of the light transmittance of the second light control means by the control means is performed by the light control element driving means. It is made by driving a light control device, and the light control device is composed of a liquid crystal device or electrochromic using chemical change, and light is most transmitted among the light transmittance of the second light control means. maximum The light transmittance is τmax, the minimum light transmittance at which light is hardly transmitted is τmin, the light control range of the second light control means is τA = τmax−τmin, and the light reduction filter includes two light reduction filter pieces. ND1 and ND2, and when the light transmittances of these two neutral density filter pieces ND1 and ND2 are τND1 and τND2 (where τND1> τND2) and τND1−τND2 = ΔτND, τA ≧ ΔτND It is set so that it may become.
The light control device according to the present invention is a light control device that adjusts the amount of transmitted light, and is a first light control device that is positioned on an optical path through which light passes and whose light transmittance can be adjusted stepwise. A dimming unit, a second dimming unit positioned on the optical path and configured to continuously adjust the light transmittance, the light transmittance of the first dimming unit, and the second Control means for controlling the light transmittance of the light control means, wherein the first light control means is a neutral density filter having a predetermined light transmittance, and the neutral density filter is located on the optical path. A light-reducing filter moving unit that moves to an operating position and a non-operating position retracted from the optical path, and the light transmittance of the first light-modulating unit is controlled by the control unit. Moving the neutral density filter between the operating position and the non-operating position by Therefore, the neutral density filter is composed of a plurality of neutral density filter pieces having different light transmittances τN and arranged in a plane, and one neutral density filter piece selected from the multiple neutral density filter pieces is provided. The remaining dimming filter piece is configured to be positioned in the non-operating position when positioned in the operating position, the dimming filter is configured with an ND filter, and the second dimming means includes a dimming element And a dimming element driving means for driving the dimming element, and the control of the light transmittance of the second dimming means by the control means drives the dimming element by the dimming element driving means. The dimming element is composed of a liquid crystal element or electrochromic using a chemical change, and has the maximum light transmittance through which light is most transmitted among the light transmittances of the second dimming means. τmax and , The minimum light transmittance at which light is hardly transmitted is τmin, the light control range of the second light control means is τA = τmax−τmin, and the light reduction filter includes three or more light reduction filter pieces ND1, ND2, ... NDn (where n is an integer greater than or equal to 3), and the light transmittances of the plurality of neutral density filters ND1, ND2,... NDn are respectively τND1, τND2, ..., τNDn (where τND1> τND2 >,...> .Tau.NDn), and when .tau.ND1-.tau.ND2, .tau.ND2-.tau.ND3,..., .Tau.ND (n-1)-. Tau.NDn is set to .DELTA..tau.NDmax, .tau.A.gtoreq..DELTA..tau.NDmax. It is characterized by being.
The light control device according to the present invention includes an imaging optical system, an imaging element that captures an image formed by the imaging optical system and outputs an imaging signal, and a transmitted light amount of light reaching the imaging element. A first light control device configured to adjust a light transmittance of the imaging device having a light control device to be adjusted, the light control device being positioned on an optical path through which light passes. Means, a second light control means arranged on the optical path and configured to continuously adjust the light transmittance thereof, the light transmittance of the first light control means and the second light control means. Control means for controlling the light transmittance of the light means, wherein the first light control means and the second light control means are disposed between the photographing optical system and the image sensor, and the first light control means. The light means includes a neutral density filter having a predetermined light transmittance, and an operation for positioning the neutral density filter on the optical path. And a neutral density filter moving means for moving to a non-operating position retracted from the optical path, and the control means controls the light transmittance of the first dimming means by the neutral density filter moving means. The neutral density filter is made by moving the neutral density filter between the operating position and the non-operative position, and the neutral density filter is composed of a plurality of neutral density filter pieces having different light transmittances τN and arranged in a plane. When one neutral density filter piece selected from a plurality of neutral density filter pieces is located at the operating position, the remaining neutral density filter pieces are arranged at the non-operative position, and the neutral density filter is ND. is composed of a filter, the second light control means comprises a dimmer element, and a light adjusting device control means for driving the light control device, the light transmittance of the by the control means second light control means Rate control Is made by driving the dimming element by the dimming element driving means, and the dimming element is composed of a liquid crystal element or electrochromic using a chemical change, and light transmission of the second dimming means. The maximum light transmittance through which light is most transmitted is τmax, the minimum light transmittance through which light is the least transmitted is τmin, the light control range of the second light control means is τA = τmax−τmin, The neutral density filter is composed of two neutral density filter pieces ND1 and ND2. The optical transmittances of the two neutral density filter pieces ND1 and ND2 are τND1 and τND2 (where τND1> τND2), respectively, and τND1−τND2 = When ΔτND is set, τA ≧ ΔτND is set.
The light control device according to the present invention adjusts the imaging optical system, an imaging element that captures an image formed by the imaging optical system and outputs an imaging signal, and the amount of transmitted light that reaches the imaging element A light control device, wherein the light control device is located on an optical path through which light passes and is configured to adjust its light transmittance stepwise; A second light control means which is located on the optical path and is configured so that the light transmittance thereof can be continuously adjusted; the light transmittance of the first light control means; and the second light control means. Control means for controlling the light transmittance of the first light control means, and the first light control means and the second light control means are disposed between the photographing optical system and the image sensor, and the first light control means. A neutral density filter having a predetermined light transmittance, and an operating position where the neutral density filter is located on the optical path; A light-reducing filter moving unit that moves to a non-operating position retracted from the light path, and the light transmittance of the first light control unit by the control unit is controlled by the light-reducing filter moving unit. The light filter is made by moving the optical filter to the operating position and the non-operating position, and the neutral density filter includes a plurality of neutral density filter pieces having different light transmittances τN and arranged in a plane. When one of the neutral density filter pieces selected from the neutral density filter pieces is located at the operating position, the remaining neutral density filter pieces are arranged at the non-operative position, and the neutral density filter is an ND filter. constructed, the second light control means comprises a dimmer element, and a light adjusting device control means for driving the light control device, the light transmittance of the by the control means second light control means Control is the above The dimming element is driven by the dimming element driving means, and the dimming element is constituted by a liquid crystal element or electrochromic using chemical change, and the light transmittance of the second dimming means. Of these, the maximum light transmittance through which light is most transmitted is τmax, the minimum light transmittance through which light is the least transmitted is τmin, the light control range of the second light control means is τA = τmax−τmin, The filter is composed of three or more neutral density filter pieces ND1, ND2,... NDn (where n is an integer greater than or equal to 3), and the light transmittance of these multiple neutral density filters ND1, ND2,. .Tau.ND1, .tau.ND2,..., .Tau.NDn (where .tau.ND1>.tau.ND2>,...> .Tau.NDn) and .tau.ND1-.tau.ND2, .tau.ND2-.tau.ND3,..., .Tau.ND (n-1)-. Tau.NDn Is set so that τA ≧ ΔτNDmax, where ΔτNDmax is the maximum value.

Therefore, the light transmittance of the light control device is adjusted over a wide range by adjusting the light transmittance stepwise by the first light control means and continuously adjusting the light transmittance by the second light control means. It can be adjusted continuously.
Further, since the first and second light control means do not use the iris diaphragm, the light transmitted through the first and second light control means does not need to be a parallel light beam. As a result, the photographing optical system does not have to generate parallel rays, so that the configuration can be simplified and the optical path length can be shortened.
Therefore, according to the light control device and the imaging device according to the present invention, it is advantageous in expanding the light amount adjustment range and reducing the size.

  The objective of expanding the light amount adjustment range and reducing the size was realized with a simple configuration without using an iris diaphragm.

Next, Embodiment 1 of the present invention will be described with reference to the drawings.
1 is a block diagram illustrating a schematic configuration of an imaging device and a light control device according to the first embodiment, FIG. 2 is a configuration diagram of the imaging device and the light control device, FIG. 3 is a perspective view illustrating a main part of the light control device, and FIG. FIG. 4A is a diagram showing a change in light transmittance of the first light control means, FIG. 4B is a diagram showing a change in light transmittance of the second light control means, and FIG. 4C is a light control. It is a figure which shows the change of the light transmittance of an apparatus.

As shown in FIG. 1, the imaging device 10 includes a photographic optical system 12, an imaging element 14, and a light control device 16, and is configured to capture still images and moving images.
The photographic optical system 12 is composed of a plurality of lenses disposed in a lens barrel 1202 and is configured to form a subject image on the image sensor 14.
The imaging element 14 is disposed at the rear end of the lens barrel 1202 and is configured to output an imaging signal from an image formed by the imaging optical system 12. In this example, the imaging element 14 is configured by a CCD or the like. Yes.
The image pickup signal is taken in by the arithmetic processing unit 18, subjected to predetermined signal processing by the arithmetic processing unit 18, and output as a video signal. The video signal is supplied to a display (not shown) to display a video, and is supplied to a recording / reproducing unit (not shown) to record the video on a recording medium.

The light control device 16 controls the first and second light control means 20 and 22 provided between the photographing optical system 12 and the image sensor 14, and the first and second light control means 20 and 22. And control means 24 for performing.
As shown in FIG. 2, the first light control means 20 includes a neutral density filter 2002 disposed on the optical path of the photographing optical system 12 behind the photographing optical system 12, and a neutral density filter 2002 on the optical path. It is composed of a neutral filter moving means 2004 that moves to an operating position that is positioned and a non-operating position that is retracted from the optical path.
More specifically, as shown in FIG. 3, the neutral density filter 2002 includes a plurality of neutral density filter pieces having different light transmittances. In this example, the neutral density filter 2002 includes first to third neutral density filter pieces 2006, 2008, and 2010 made of ND filters. In the present example, τN1>τN2> τN3 when the light transmittances of the first to third neutral density filter pieces 2006, 2008, and 2010 are τN1, τN2, and τN3, respectively.
The first to third neutral density filter pieces 2006, 2008, and 2010 are held by the frame body 2012. The frame body 2012 has two vertical pieces extending in the vertical direction and a connecting piece for connecting the lower portions of the two vertical pieces, and the first to third reduction pieces are provided between the two vertical sides and the connecting piece. Optical filter pieces 2006, 2008, and 2010 are attached.
Guide grooves are formed to extend in the two vertical pieces, and these guide grooves are guided by a guide member (not shown) provided in the lens barrel 1202, so that the neutral density filter 2002 is orthogonal to the optical path L. It is held movably in the direction. In this example, the first to third neutral density filter pieces 2006, 2008, and 2010 are arranged in a plane along the moving direction of the frame body 2012.
The neutral density filter moving unit 2004 includes an actuator 2014 having a swing arm 2006 that swings around a support shaft, and the tip of the swing arm 2016 is connected to a connecting piece of the frame body 2012. Therefore, the frame 2012 is configured to move in the vertical direction when the swing arm 2016 swings.
Further, when the frame 2012 is moved by the neutral density filter moving means 2004, one neutral density filter piece selected from the first to third neutral density filter pieces 2004, 2006, 2008 is located at the operating position. Sometimes the remaining neutral density filter pieces are arranged in the non-actuated position.
Accordingly, the frame body 2012 is moved by the neutral density filter moving means 2004, and one neutral density filter piece selected from the first to third neutral density filter pieces 2004, 2006, 2008 is located at the operating position, The light transmittance can be adjusted step by step to τN1, τN2, and τN3. Further, when the frame 2012 is moved by the neutral density filter moving means 2004 and the neutral density filter 2002 is located at the non-operation position, the light transmittance is configured to be maximum (100%).

As shown in FIG. 1, the second dimming unit 22 includes a dimming element disposed on the optical path of the imaging optical system 12 between the neutral density filter 2002 of the first dimming unit 20 and the image sensor 14. 2202 and dimming element driving means 2204 for driving the dimming element 2202.
In this example, the light control element 2202 is constituted by a liquid crystal element, and the light control element driving means 2204 gives a drive signal to the light control element 2202, so that light is most transmitted through the light transmittance τ of the light control element 2202. The maximum light transmittance is configured to be continuously adjustable between τmax and the minimum light transmittance τmin that transmits the least light. Therefore, the dimming range τA of the dimming element 2202 by the second dimming means 22 is τmax−τmin. Further, in this example, it is assumed that τmax of the light control element 2202 is 100%.

  The control means 24 is constituted by a microcomputer in this example, and controls the light-reducing filter moving means 2004 and the light-modulating element driving means 2204, whereby the light transmittance by the first light-modulating means 20 and the second light-transmitting ratio are controlled. The light transmittance by the light control means 22 is configured to be controlled.

Next, operations of the imaging device 10 and the light control device 16 of the present embodiment will be described.
4A is a diagram for explaining the adjustment of the transmitted light amount by the first light control means 20, FIG. 4B is a diagram for explaining the adjustment of the transmitted light quantity by the second light control means 22, and FIG. 4C is a light control device. FIG. 16 is a diagram illustrating adjustment of transmitted light amount by 16; 4A to 4C, the horizontal axis indicates time (arbitrary unit), the vertical axis indicates the transmitted light amount (arbitrary unit), and the value of the transmitted light amount on the vertical axis decreases as it goes upward, and goes downward. The value is large.
Hereinafter, a case where the amount of transmitted light is changed from the maximum value to the minimum value between time t0 and time t4 will be described.
First, at the time t0, the neutral density filter 2002 of the first dimming means 20 is located at the non-operating position by the control of the control means 24 (FIG. 4A), and the second dimming means. The 22 light control elements 2202 have the maximum light transmittance τmax (FIG. 4B). Therefore, the light transmittance of the light control device 16 is τ0 = τmax (FIG. 4C).
Next, between time t0 and time t1, the transmittance τ of the dimming element 2202 of the second dimming means 22 is continuously adjusted from τmax to τC1 by the control of the control means 24 (FIG. 4). (B)). However, this τC1 is set to the light transmittance τND1 of the first neutral density filter piece 2004. Therefore, the light transmittance of the light control device 16 is continuously adjusted from τ0 to τ1 = τC1.
At time t1, the control unit 24 controls the first dimming filter piece 2004 of the first dimming unit 20 to be in the operating position (FIG. 4A). The transmittance τ of the light control element 2202 of the light control means 22 is returned to τmax (FIG. 4B). Therefore, the light transmittance of the light control device 16 is τ1 = τC1 (FIG. 4C).

Next, between time t1 and time t2, the transmittance τ of the dimming element 2202 of the second dimming means 22 is continuously adjusted from τmax to τC2 by the control of the control means 24 (FIG. 4). (B)). However, τC2 is set to a difference (τND1−τND2) between the light transmittance τND1 of the first neutral density filter piece 2004 and the light transmittance τND2 of the second neutral density filter piece 2006. Therefore, the light transmittance of the light control device 16 is continuously adjusted from τ1 to τ2 = τND2.
At time t2, the second neutral density filter piece 2006 of the first dimming means 20 is positioned at the operating position by the control of the control means 24 (FIG. 4A). The transmittance τ of the light control element 2202 of the light control means 22 is returned to τmax (FIG. 4B). Therefore, the light transmittance of the light control device 16 is τ2 = τND2 (FIG. 4C).

Next, during the period from time t2 to time t3, the transmittance τ of the dimming element 2202 of the second dimming means 22 is continuously adjusted from τmax to τC3 by the control of the control means 24 (FIG. 4). (B)). However, τC3 is set to a difference (τND2-τND3) between the light transmittance τND2 of the second neutral density filter piece 2006 and the light transmittance τND3 of the third neutral density filter piece 2008. Therefore, the light transmittance of the light control device 16 is continuously adjusted from τ2 to τ3 = τND3.
At time t3, the control unit 24 controls the third dimming filter piece 2008 of the first dimming unit 20 to be in the operating position (FIG. 4A). The transmittance τ of the light control element 2202 of the light control means 22 is returned to τmax (FIG. 4B). Therefore, the light transmittance of the light control device 16 is τ3 = τND3 (FIG. 4C).

Next, during the period from time t3 to time t4, the transmittance τ of the dimming element 2202 of the second dimming means 22 is continuously adjusted from τmax to τmin by the control of the control means 24 (FIG. 4). (B)). Therefore, the light transmittance of the light control device 16 is continuously adjusted from τ3 to τ4 = τND−τmin (FIG. 4C).
In this way, the light transmittance τ of the light control device 16 is continuously adjusted between τ0 and τ4.

In this embodiment, the dimming range of the second dimming means 22 is τA = τmax−τmin, and the light of the first to third neutral density filter pieces 2004, 2006, 2008 of the first dimming means 20 is used. Since the transmittances are τND1, τND2, and τND3, respectively, in order to be able to continuously adjust the light transmittance of the light control device 16, the maximum value of τND1−τND2 and τND2−τND3 (in this example, When τND2−τND3) is ΔτNDmax, it is necessary to set so that τA ≧ ΔτNDmax.
In this embodiment, the maximum light transmittance τmax of the light control element 2202 is 100%, so that τC1 = τND1, τC2 = (τND1-τND2), and τC3 = (τND2-τND3). However, when τmax is less than 100%, for example, (100−Δτ)%, a value obtained by adding the light transmittances τC1, τC2, and τC3 of the dimming element 2202 by Δτ%, that is, τC1 = τND1 + Δτ, τC2 = (ΤND1-τND2) + Δτ, τC3 = (τND2-τND3) + Δτ.

Further, when the dimming filter 2002 of the first dimming means 20 is moved between the operating position and the non-operating position in the dimming device 16, the boundaries of the respective dimming filter pieces pass on the optical path. A partial brightness difference occurs in the subject image formed on the image sensor 14. Therefore, if an image pickup operation by the image pickup device 14 is performed in this state, there is a possibility that the image pickup signal may be adversely affected.
Therefore, the movement of the neutral density filter 2002 to the operation position and the non-operation position by the neutral density filter moving unit 2004 is preferably performed during a time when the imaging operation by the imaging element 14 is not performed. In other words, it is sufficient that the captured still image and moving image are not affected.
Specifically, when capturing a still image, the movement of the neutral density filter 2002 is prohibited during the period when the imaging operation for one screen is performed, and the neutral density filter 2002 is moved during other periods. To. Further, when capturing a moving image, the movement of the neutral density filter 2002 is prohibited during a period in which an imaging operation for one frame is performed, and the neutral density filter 2002 is moved during other periods (dead zone time). To.

As described above, according to the present embodiment, the light transmittance is adjusted stepwise by the first light control means 20 and the light transmittance is continuously adjusted by the second light control means 22. The light transmittance of the light control device 16 can be continuously adjusted over a wide range. Therefore, it is advantageous in expanding the light amount adjustment range.
Further, since the first and second light control means do not use the iris diaphragm, the light transmitted through the first and second light control means does not need to be a parallel light beam. Therefore, as shown in FIG. 2, the first and second light control means 20 are on the optical path where the light converged by the photographing optical system 12 reaches the image pickup device 14, that is, between the image pickup optical system 12 and the image pickup device 14. , 22 can be arranged.
Therefore, since the photographing optical system 12 does not have to generate parallel rays, the configuration can be simplified and the optical path length can be shortened, which is advantageous in reducing the size of the imaging apparatus 10.
In addition, since the light transmitted through the first and second light control means does not need to be parallel light rays, there is no restriction on the arrangement positions of the first and second light control means, and the degree of freedom in design is ensured. This is also advantageous.

Next, a comparative example will be described.
FIG. 5 is a diagram illustrating an example of an imaging apparatus including a light control device using a conventional ND filter and an iris diaphragm.
The imaging apparatus includes imaging optical systems 52 and 54, an ND filter 56 and an iris diaphragm 58 as a light control device disposed between the imaging optical systems 52 and 54, and an imaging element 60.
The ND filter 56 is provided so as to be movable between an operating position located on the optical path and a non-operating position retracted from the optical path.
The photographing optical systems 52 and 54 are configured to converge the subject image and form the image on the image sensor 60, and are configured so that the light becomes parallel rays at the iris diaphragm 58.
Therefore, it is clear that the configuration of the imaging optical systems 52 and 54 is complicated and the optical path length is longer than that in FIG. 2 showing the present embodiment. It turns out to be advantageous.

In the present embodiment, the dimming filter 2002 is arranged in front of the dimming element 22, but it is needless to say that the dimming element 22 may be arranged in front of the dimming filter 2002.
Further, although a liquid crystal element is used as the light control element 2202, any element can be used as long as the light transmittance can be continuously adjusted. For example, electrochromic using chemical change may be used.
In addition, it is optional to provide an iris diaphragm in the light control device and the imaging device of the present invention.

In the present embodiment, the case where the neutral density filter 2002 is composed of three neutral density filter pieces has been described. However, the number of neutral density filter pieces is one, two, or N (N is 3 or more). An optical filter may be used.
However, it is assumed that the neutral density filter piece 2002 includes two neutral density filter pieces ND1 and ND2, and the light transmittances of these two neutral density filter pieces ND1 and ND2 are τND1 and τND2 (where τND1> τND2), respectively. , .Tau.ND1-.tau.ND2 = .DELTA..tau.ND, when .tau.A.gtoreq..DELTA..tau.ND.
Further, it is assumed that the neutral density filter 2002 is composed of N neutral density filter pieces ND1, ND2,... NDn (n is an integer of 3 or more), and these N neutral density filter pieces ND1, ND2,. ... NDn has a light transmittance of τND1, τND2, ..., τNDn (where τND1>τND2>,...> τNDn), and τND1-τND2, τND2-τND3, ... It is only necessary to set τA ≧ ΔτNDmax when the maximum value is ΔτNDmax.

1 is a block diagram illustrating a schematic configuration of an imaging device and a light control device according to Embodiment 1. FIG. It is a block diagram of an imaging device and a light control device. It is a perspective view which shows the principal part of a light modulation apparatus. It is a figure which shows the change of the light transmittance of a 1st light control means. It is a figure which shows the change of the light transmittance of a 2nd light control means. It is a figure which shows the change of the light transmittance of a light modulation apparatus. It is a figure which shows the example of the light modulation apparatus using the conventional ND filter and iris diaphragm.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Imaging device, 12 ... Imaging optical system, 14 ... Imaging element, 16 ... Light control device, 18 ... Arithmetic processing part, 20 ... 1st light control means, 22 ... 2nd light control Light means.

Claims (5)

A light control device for adjusting the amount of transmitted light,
A first dimmer configured to adjust the light transmittance in a stepwise manner on an optical path through which light passes;
A second dimmer configured to be located on the optical path and configured to continuously adjust the light transmittance;
Control means for controlling the light transmittance of the first light control means and the light transmittance of the second light control means;
The first dimming means includes a neutral density filter having a predetermined light transmittance, and a neutral density filter that moves the neutral density filter to an operating position positioned on the optical path and a non-operating position retracted from the optical path. Filter moving means,
Control of the light transmittance of the first dimming means by the control means is performed by moving the neutral density filter to the operating position and the non-operating position by the neutral density filter moving means,
The neutral density filter includes a plurality of neutral density filter pieces having different light transmittances τN and arranged in a plane, and one neutral density filter piece selected from the multiple neutral density filter pieces is in the operating position. The remaining neutral density filter piece is configured to be located in a non-actuated position when
The neutral density filter is composed of an ND filter,
The second light control means has a light control element and a light control element driving means for driving the light control element,
Control of the light transmittance of the second light control means by the control means is performed by driving the light control element by the light control element driving means,
The light control device is composed of a liquid crystal device or electrochromic using chemical change,
Of the light transmittance of the second light control means, the maximum light transmittance through which light is most transmitted is τmax, the minimum light transmittance through which light is the least transmitted is τmin, and light control of the second light control means is performed. The range is τA = τmax−τmin, and the neutral density filter is composed of two neutral density filter pieces ND1 and ND2. The optical transmittances of these two neutral density filter pieces ND1 and ND2 are respectively τND1 and τND2 (however, τND1> τND2) and τND1−τND2 = ΔτND, where τA ≧ ΔτND is set.
A light control device characterized by that. A light control device for adjusting the amount of transmitted light,
A first dimmer configured to adjust the light transmittance in a stepwise manner on an optical path through which light passes;
A second dimmer configured to be located on the optical path and configured to continuously adjust the light transmittance;
Control means for controlling the light transmittance of the first light control means and the light transmittance of the second light control means;
The first dimming means includes a neutral density filter having a predetermined light transmittance, and a neutral density filter that moves the neutral density filter to an operating position positioned on the optical path and a non-operating position retracted from the optical path. Filter moving means,
Control of the light transmittance of the first dimming means by the control means is performed by moving the neutral density filter to the operating position and the non-operating position by the neutral density filter moving means,
The neutral density filter includes a plurality of neutral density filter pieces having different light transmittances τN and arranged in a plane, and one neutral density filter piece selected from the multiple neutral density filter pieces is in the operating position. The remaining neutral density filter piece is configured to be located in a non-actuated position when
The neutral density filter is composed of an ND filter,
The second light control means has a light control element and a light control element driving means for driving the light control element,
Control of the light transmittance of the second light control means by the control means is performed by driving the light control element by the light control element driving means,
The light control device is composed of a liquid crystal device or electrochromic using chemical change,
Of the light transmittance of the second light control means, the maximum light transmittance through which light is most transmitted is τmax, the minimum light transmittance through which light is the least transmitted is τmin, and light control of the second light control means is performed. The range is τA = τmax−τmin, and the neutral density filter is composed of three or more neutral density filter segments ND1, ND2,... NDn (where n is an integer greater than or equal to 3). ND1, ND2,... NDn light transmittances are .tau.ND1, .tau.ND2,..., .Tau.NDn (where .tau.ND1>.tau.ND2>,. 1) When ΔτNDmax is the maximum value of −τNDn, τA ≧ ΔτNDmax is set.
A light control device characterized by that. Photographic optics,
An imaging device that captures an image formed by the imaging optical system and outputs an imaging signal;
An imaging device comprising a light control device for adjusting a transmitted light amount of light reaching the imaging device,
The light control device is:
A first dimmer configured to adjust the light transmittance in a stepwise manner on an optical path through which light passes;
A second dimmer configured to be located on the optical path and configured to continuously adjust the light transmittance;
Control means for controlling the light transmittance of the first light control means and the light transmittance of the second light control means;
The first light control means and the second light control means are disposed between the imaging optical system and the image sensor,
The first dimming means includes a neutral density filter having a predetermined light transmittance, and a neutral density filter that moves the neutral density filter to an operating position positioned on the optical path and a non-operating position retracted from the optical path. Filter moving means,
Control of the light transmittance of the first dimming means by the control means is performed by moving the neutral density filter to the operating position and the non-operating position by the neutral density filter moving means,
The neutral density filter includes a plurality of neutral density filter pieces having different light transmittances τN and arranged in a plane, and one neutral density filter piece selected from the multiple neutral density filter pieces is in the operating position. The remaining neutral density filter piece is configured to be located in a non-actuated position when
The neutral density filter is composed of an ND filter,
The second light control means has a light control element and a light control element control means for driving the light control element,
Control of the light transmittance of the second light control means by the control means is performed by driving the light control element by the light control element driving means,
The light control device is composed of a liquid crystal device or electrochromic using chemical change,
Of the light transmittance of the second light control means, the maximum light transmittance through which light is most transmitted is τmax, the minimum light transmittance through which light is the least transmitted is τmin, and light control of the second light control means is performed. The range is τA = τmax−τmin, and the neutral density filter is composed of two neutral density filter pieces ND1 and ND2. The optical transmittances of these two neutral density filter pieces ND1 and ND2 are respectively τND1 and τND2 (however, τND1> τND2) and τND1−τND2 = ΔτND, where τA ≧ ΔτND is set.
An imaging apparatus characterized by that. Photographic optics,
An imaging device that captures an image formed by the imaging optical system and outputs an imaging signal;
An imaging device comprising a light control device for adjusting a transmitted light amount of light reaching the imaging device,
The light control device is:
A first dimmer configured to adjust the light transmittance in a stepwise manner on an optical path through which light passes;
A second dimmer configured to be located on the optical path and configured to continuously adjust the light transmittance;
Control means for controlling the light transmittance of the first light control means and the light transmittance of the second light control means;
The first light control means and the second light control means are disposed between the imaging optical system and the image sensor,
The first dimming means includes a neutral density filter having a predetermined light transmittance, and a neutral density filter that moves the neutral density filter to an operating position positioned on the optical path and a non-operating position retracted from the optical path. Filter moving means,
Control of the light transmittance of the first dimming means by the control means is performed by moving the neutral density filter to the operating position and the non-operating position by the neutral density filter moving means,
The neutral density filter includes a plurality of neutral density filter pieces having different light transmittances τN and arranged in a plane, and one neutral density filter piece selected from the multiple neutral density filter pieces is in the operating position. The remaining neutral density filter piece is configured to be located in a non-actuated position when
The neutral density filter is composed of an ND filter,
The second light control means has a light control element and a light control element control means for driving the light control element,
Control of the light transmittance of the second light control means by the control means is performed by driving the light control element by the light control element driving means,
The light control device is composed of a liquid crystal device or electrochromic using chemical change,
Of the light transmittance of the second light control means, the maximum light transmittance through which light is most transmitted is τmax, the minimum light transmittance through which light is the least transmitted is τmin, and light control of the second light control means is performed. The range is τA = τmax−τmin, and the neutral density filter is composed of three or more neutral density filter segments ND1, ND2,... NDn (where n is an integer greater than or equal to 3). ND1, ND2,... NDn light transmittances are .tau.ND1, .tau.ND2,..., .Tau.NDn (where .tau.ND1>.tau.ND2>,. 1) When ΔτNDmax is the maximum value of −τNDn, τA ≧ ΔτNDmax is set.
An imaging apparatus characterized by that.   5. The imaging according to claim 3 or 4, wherein the movement of the neutral density filter to the operating position and the non-operating position by the neutral density filter control means is performed during a period in which an imaging operation by the imaging element is not performed. apparatus.

Images