JPH05313076A - Optical quantity adjusting device and optical device having the device - Google Patents

Abstract

PURPOSE:To provide practival use of an optical quantity adjusting device by arranging the first and the second optical quantity adjusting elements longitudinally on the same optical axis, and driving transparent advancing/retreating plates of both the elements. CONSTITUTION:In the first optical quantity adjusting element 101, the first fluid 15 is enclosed in a space surrounded by a cylindrical body 14 and transparent plates 12 and 13. In the second optical quantity adjusting element 102, the second fluid 19 is sealed up in a space surrounded with a cylindrical body 18 and transparent plates 16 and 17. The transparent plates 13 and 16 are held in the central part of a frame body 801, and a movable member 802 is arranged in the axial Z direction to the frame body 801, and is connected to a cylindrical vibrator 10a of a voice coil type actuator. The transparent plates 12 and 17 are fixed to the frame body 801. When the voice coil type actuator is driven, the vibrator 10a moves in parallel with the axis Z, and the transparent plates 13 and 16 move along the axis Z through the movable member 802. Thereby, spaces between the transparent plates are changed, and a light transmitting quantity or an optical path length can be adjusted simultaneously.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical amount adjusting device used for an optical device and the like and an optical device having the optical amount adjusting device.

[0002]

2. Description of the Related Art Conventionally, an electric light quantity adjusting device in which diaphragm blades are driven by an electromagnetic actuator has been used in optical devices such as still cameras and video cameras. This known electrically operated light amount adjusting device has become highly reliable due to long manufacturing experience so far, but recently, development of an unconventional light amount adjusting device which does not require diaphragm blades has been attempted.

The following are known as such non-conventional light quantity adjusting devices.

A liquid crystal device.

A space between a pair of transparent plates facing each other and separated from each other is surrounded by a flexible tubular body which can be expanded and contracted in a bellows shape, and both ends of the tubular body are fixed to the outer periphery of the transparent plate. A liquid chamber surrounded by both transparent plates and the cylindrical body is formed,
The liquid chamber is divided into front and rear by an elastic transparent film parallel to the transparent plate to form a first chamber and a second chamber, and the first chamber and the second chamber are respectively filled with liquids having different light transmittances. Then, the first transparent plate and the second transparent plate are moved back and forth relatively to each other to change the ratio of the liquid amounts in the first chamber and the second chamber, and A device that changes the amount of light transmitted through the liquid in both chambers (see, for example, JP-A-1-304417).

The space between the first and second transparent plates which face each other and are spaced apart from each other is surrounded by a flexible cylindrical body which can be expanded and contracted in a bellows shape, and is surrounded by the both transparent plates and the cylindrical body. A liquid chamber is formed, and by applying a voltage to a piezoelectric element attached to one of the transparent plates, one of the transparent plates is moved back and forth with respect to the other transparent plate, and the length of the liquid chamber in the optical axis direction ( That is, the length of the light in the light transmission direction is changed, thereby changing the amount of light transmitted through the both transparent plates and the liquid in the liquid chamber (JP-A-62-62).
2656185).

On the other hand, no optical device such as a video camera using the fluid type of the above-mentioned non-conventional light quantity adjusting device has been proposed so far.

[0008]

The above-mentioned non-conventional light intensity adjusting devices have the following problems.

Since the liquid crystal type light quantity adjusting device of (1) has a slow response speed and has a very narrow variable range, it is not suitable for use in an optical device such as a video camera.

Regarding the fluid type light quantity adjusting device of Japanese Patent Application Laid-Open No. HEI-1
JP-A-304417 does not disclose a configuration capable of uniformly changing the light transmission opening, and is not suitable for practical use.

In the fluid type light quantity adjusting device, a piezoelectric element is used as a drive source for moving the transparent plate. However, depending on the piezoelectric element, the transparent plate cannot be continuously moved, so that it is not suitable for practical use. ..

On the other hand, an optical device such as a video camera using the above-mentioned light amount adjusting device has not been proposed yet, but when the above-mentioned light amount adjusting device is mounted on a video camera or the like, the light amount adjusting device Since the optical path length changes with the operation, there is a problem in that the focal position is displaced and a clear image cannot be obtained.

A first object of the present invention is to solve the problems inherent in the above-mentioned non-conventional light amount adjusting device and to provide an optical amount adjusting device which can be put to practical use.

A second object of the present invention is to provide a practical optical device such as a video camera having the novel optical quantity adjusting device according to the present invention.

[0015]

In the present invention, continuous control is possible by using a voice coil type actuator, a known cam ring or the like as a driving means for driving the transparent plate of the fluid type optical quantity adjusting element. did. Further, at least two of the optical quantity adjusting elements are arranged in tandem,
Operate each element simultaneously or separately to adjust the amount of transmitted light in a wide range, or
Each element has a different function so that two or more functions can be adjusted at the same time. Further, a practical optical device equipped with the optical quantity adjusting device of the present invention was proposed.

[0016]

Embodiments of the optical quantity adjusting device of the present invention and an optical device having the device will be described below.

An optical amount adjusting element, which is a main component of the optical amount adjusting device, will be described below with reference to the drawings.

FIG. 9 is a view for explaining a function common to the optical quantity adjusting element according to the present invention and the light quantity adjusting element of the fluid type transmitted light quantity adjusting device described in the section [Prior Art].

In FIG. 9, (A) is a schematic diagram corresponding to (a), (B) is a schematic diagram corresponding to (b), and (C) is a schematic diagram corresponding to (c). As shown in the same figure, the optical quantity adjusting element includes first and second transparent plates 1 and 2 which face each other and are spaced apart from each other, and the transparent plates 1 and 2
A cylindrical body 3 made of a flexible and non-translucent material, the both ends of which are fixed to the outer periphery of the transparent body and surrounds the space between the transparent plates.
It is composed of an opaque fluid substance 4 filled in a closed space surrounded by the both transparent plates and the cylindrical body.

FIGS. 3A and 3A show the state in which the cylindrical body 3 is at its maximum extension and the distance between the two transparent plates is at the maximum value d1.

The light Lin incident on the transparent plate 1 is a fluid substance 4
Because they are scattered or absorbed by the particles in
The light Lout transmitted through the transparent plate 2 is Lout <Lin.

FIGS. 9B and 9B show the case where the distance between the transparent plates 1 and 2 is narrower than that in FIGS. 9A and 9A. In this case, the light Lin incident on the transparent plate 1 is a fluid. The light Lout emitted from the transparent plate 2 is Lout <Lin because it is scattered or absorbed by the particles in the substance 4.

FIGS. 9C and 9C show a state where the transparent plates 1 and 2 are in close contact with each other, and in this case, between the light Lin incident on the transparent plate 1 and the light Lout emitted from the transparent plate 2. Is L
The relation of out≈Lin is established.

As the fluid substance 4, for example, a liquid in which a black paint is dissolved is used, and the distance between the transparent plates 1 and 2 is set to 1 mm.
Assuming that the fluid substance 3 is prepared to have a transmittance t × 100%, the transmittance T is T = t ^d × 100%,

[0025]

[Equation 1]

Is satisfied. Here, d is the distance between both transparent plates, that is, the permeation thickness of the fluid substance layer.

FIG. 10 shows the relationship between the transparent plate spacing d and the transmittance T of the optical adjustment element when t = 0.01 and t = 0.1 in the above relational expression. If the transparent plate spacing d changes by 0 to 2 mm, t = 0.
In the case of 01, the light transmittance T of the device is 100% to 2 ^-13.3
× 100%, and the change amount of the light transmittance of the device when t = 0.1 is 100% to 2 ^−6.6 × 100%.

When fluids having different light transmittances are used as the opaque fluid filling the space between the transparent plates in this way, the light transmittance of the element is changed even if the amount of change in the distance between the transparent plates is the same. be able to. It should be noted that if the refractive index of the opaque fluid and the refractive index of the transparent plate are made substantially equal to each other, the optical adverse effect at the boundary surface between the fluid and the transparent plate can be reduced.

FIG. 11 shows an example of the mechanical structure of the optical quantity adjusting element. FIG. 11A shows that the rings 5 and 6 are used to fix both ends of the flexible tubular body 3 to the outer circumferences of the transparent plates 1 and 2, and the ring 5 is fitted to the outer circumference of the transparent plate 1. Then, the front end of the tubular body 3 is fixed to the outer periphery of the transparent plate 1, and the ring 6 is fitted to the outer periphery of the transparent plate 2, whereby the rear end of the tubular body 3 is fixed to the outer periphery of the transparent plate 2.

FIG. 11B shows that the peripheral wall portion of the fluid chamber between the transparent plates 1 and 2 is constituted by a rigid cylindrical body 7 instead of a flexible cylindrical body, and the cylindrical body 7 is formed by the transparent plate 2. A rigid cylindrical body 8 extending rearward of the transparent plate 2 and fitted to the outer periphery of the transparent plate 2 is slidably fitted to the inner peripheral surface of the rear portion of the cylindrical body 7. A hole 7a through which the fluid 4 flows in and out is provided through the peripheral wall portion of the cylindrical body 7.
A fluid reservoir 9 having a closed space communicating with a is fixed to the outer peripheral surface of the cylindrical body 7. The hole 7a is opened and closed by the forward and backward movement of the cylindrical body 8. When the transparent plates 1 and 2 are in close contact with each other, the fluid 4 between the transparent plates 1 and 2 is all pushed out into the fluid pool 9. At the same time, the hole 7a is closed by the cylindrical body 8. When the transparent plate 2 is separated from the transparent plate 1 as shown in the figure, the hole 7a is opened so that the fluid 4 in the fluid reservoir 9 flows into the space formed between the transparent plates 1 and 2. The cylindrical body 8 is directly or indirectly connected to a voice coil type actuator or a solenoid type actuator, which will be described later, and is axially driven by the actuator.

FIG. 11 (c) shows a structure in which transparent concave plates 1A and 2A are used as the transparent plate instead of the flat plate, and the peripheral wall portion of the fluid chamber between the transparent concave plates 1A and 2A is flexible. It is composed of a flexible tubular body 3, and the front end and the rear end of the tubular body 3 are rings 5 and 6 as in FIG.
And 2A are fixed to the respective outer peripheries. According to the structure of this example, it is possible to prevent the imaging ability of the photographing optical system from being deteriorated and reduce the difference in transmittance due to the difference in the optical path length between the vertically incident light and the obliquely incident light.

FIG. 12 is a schematic view of a first embodiment of an optical quantity adjusting device of the present invention constructed by using the above-mentioned optical quantity adjusting element. In the apparatus of this embodiment, a voice coil type (or solenoid type) actuator 10 is used as a drive source for moving the transparent plate 2 forward and backward with respect to the transparent plate 1. It should be noted that, in this figure, the same components as those of the elements described above are indicated by the reference numerals described above, and therefore the description of the components already described is omitted.

In the present embodiment, a metal tubular body fitted to the rear transparent plate 2 serves as a driven element of the voice coil type actuator 10, and the driven element is located outside the driven element 10a. A coil 10b that generates a magnetic field for causing axial movement is arranged with a slight gap with respect to the outer peripheral surface of the cylindrical body 10a. The energization time and the energization direction of the coil 10b are controlled by the control device 11 connected to the coil. When a voice coil type actuator is used as a drive source as in this embodiment, a long stroke can be moved at high speed, so that an optical amount adjusting device suitable for an optical device can be realized. The transparent plate 1 or 2 may be moved in the axial direction by a rotary motor and a helicoid instead of the voice coil actuator.

1 shows a first embodiment of an optical quantity adjusting device of the present invention constructed by arranging two of the above-mentioned optical quantity adjusting elements of FIG. 1 in tandem. In the figure, 101
Reference numerals 102 and 102 denote optical quantity adjusting elements having the above-described structure. The first element 101 has transparent plates 12 and 13 and a flexible tubular body 14, and the tubular body 14 and both transparent plates 12 and 13 are provided.
The first fluid 15 is enclosed in the space surrounded by. The second element 102 is composed of transparent plates 16 and 17 and a flexible tubular body 18, and the tubular body 18 and both transparent plates 16 and 1 are provided.
A second fluid 19 is enclosed in the space surrounded by 7. Reference numeral 801 denotes a frame body that is fixed to an optical device (not shown) such as a lens barrel for a video camera.
A movable member 802 that holds the transparent plates 13 and 16 in the central portion of 01 and is movable in the axial direction with respect to the frame body 801.
The movable member 802 is connected to the tubular driven element 10a of the voice coil type actuator 10 described above. In addition, the transparent plate 12 of the element 101 and the element 102
The transparent plate 17 is fixed by a frame 801 so as not to move.

In the above structure, when the voice coil type actuator 10 is driven, the driven element 10a of the actuator 10 is moved in parallel with the axis Z, so that the transparent plate 13 of the elements 101 and 102 is moved through the movable member 802. 16 is moved along the axis Z and the elements 101 and 1
The state of 02 can be changed as shown in (a) to (c) of FIG.

FIG. 3 shows another embodiment of the optical quantity adjusting device of the present invention in which two of the above-mentioned optical quantity adjusting elements are arranged in tandem. In the figure, reference numeral 1004 denotes a frame body that is stationaryly arranged in the cam cylinder 1005 of FIG. 7B, and the transparent plate 13 behind the element 101 and the element 102 are arranged in the center of the frame body 1004. A fixing member 1003 for fixing the front transparent plate 16 is fixed. Reference numeral 1001 denotes a movable member which holds the transparent plate 12 in front of the element 101 and is supported so as to be movable in parallel with the axis Z with respect to the frame body 1004.
A follower pin 1001a slidably inserted into the cam groove 1005a of the cam barrel 1005 of FIG. Reference numeral 1002 denotes a movable member that holds the transparent plate 17 behind the element 102 and is supported by the frame body 1004 so as to be movable in parallel to the axis line z with respect to the frame body 1004.
On the outer periphery of the movable member 1002, the cam cylinder 100 of FIG.
A follower pin 1002a slidably inserted into the cam groove 1005b of No. 5 is provided in a protruding manner.

The cam barrel 1005 is rotatably supported in a lens barrel of an optical device (not shown), and is rotationally driven by a rotary actuator in the optical device.

In the above structure, when the cam barrel 1005 is rotated by the actuator about the axis z by a predetermined angle, the follower pins 1001a and 1002a are rotated.
In the cam grooves 1005a and 1005b of the cam barrel 1005 slide in the longitudinal direction of the grooves to change their respective axial positions, so that the axial positions of the transparent plates 12 and 16 of the elements 101 and 102 change, The thickness of the fluid layer of the elements 101 and 102 will change, whereby the light amount adjustment and the like in the optical amount adjusting device will be performed. In the case of this embodiment, the relative positions of the transparent plates 12 and 16 in the axial direction can be set differently from the above embodiment by the shapes of the cam grooves 1005a and 1005b. It can be set in more ways than the one shown.

FIGS. 4 to 6 are schematic views showing an embodiment of a two-integrated optical quantity adjusting element in which two of the above-mentioned elements are integrated and an optical quantity adjusting device having the two-integral integrated element. ..

In the figure, 20 is a first transparent plate disposed at the foremost position, 21 is a second transparent plate disposed behind the first transparent plate 20 at a predetermined interval, and 22 is a second transparent plate. It is a third transparent plate arranged at a predetermined distance behind the plate 21, and the space between the first transparent plate 20 and the second transparent plate 21 is surrounded by the flexible tubular body 23. A first fluid chamber is formed, and a first fluid 24 is formed in the first fluid chamber.
Is enclosed. Further, the space between the second transparent plate 21 and the third transparent plate 22 is surrounded by a flexible tubular body 25 to form a second fluid chamber, and the second fluid chamber has a second fluid chamber. Fluid 26
Is enclosed.

FIG. 4 is a schematic view showing an embodiment of an optical amount adjusting device constructed by using the above-mentioned double type element. In the present embodiment, the tubular driven member 10a of the voice coil type actuator 10 is fitted around the outer periphery of the intermediate transparent plate 21, and when the actuator 10 is driven, the driven member 10 is driven.
Since a is moved in the direction of arrow A or B parallel to the axis Z, the position of the second transparent plate 21 changes, and the thicknesses of the fluid layer in the first fluid chamber and the fluid layer in the second fluid chamber are changed. Can be changed to change the amount of light transmission in the device.

In the embodiment shown in FIG. 5, the driven element 10a of the voice coil type actuator 10 is the rearmost transparent plate 2.
2 is fitted on the outer circumference of the second fluid chamber 2. Therefore, in this case, by driving the actuator 10, only the thickness of the fluid layer in the second fluid chamber can be changed.

In FIGS. 4 and 5, 10b is a coil which is the stator of the actuator 10, and 11 is a control device which controls the current flowing through the coil 10b.

FIG. 6 shows another embodiment of the optical quantity adjusting device constructed by using the above-mentioned double element and the voice coil type actuator. In this embodiment, the tubular driven element 10a of the voice coil type actuator 10 is fitted to the outer periphery of the second transparent plate 21, while the cylindrical driven element of the second voice coil type actuator 30 is attached to the outer periphery of the third transparent plate 22. Child 30a
The coils 10b and 30 of both actuators.
The control device 11 is configured to control the current for b. Therefore, in this embodiment, the second transparent plate 21 and the third transparent plate 22 can be moved simultaneously or separately.

FIG. 7 is a schematic view showing still another embodiment of the optical quantity adjusting device of the present invention constituted by using the above-mentioned double-type element. In the figure, 1101 is the first transparent plate 2.
0 and a frame body 1102 that holds the third transparent plate 22 so as not to move, a movable member 1102 that holds the second transparent plate 21 and that can move in parallel to the axis Z with respect to the frame body 1101. Reference numerals 1104 denote connecting members which connect the movable member 1102 to the cylindrical driven member 10a of the voice coil type actuator 10. Also in the case of this embodiment, as in the above-described embodiments, the thickness of the fluid layer in the first fluid chamber and the thickness of the fluid layer in the second fluid chamber can be simultaneously changed by moving the second transparent plate 21 by the actuator. it can.

FIG. 8 shows the operating state of the transparent plates 20 to 22 in the optical quantity adjusting device having the configuration of FIG.

Next, an embodiment of the optical device of the present invention having the above-described optical amount adjusting device of the present invention will be described.

FIG. 13 shows the optical quantity adjusting element shown in FIG.
It shows an embodiment of a video camera equipped with an optical quantity adjusting device having only one.

In the figure, reference numeral 50 is an optical quantity adjusting device having the element, an actuator 40, and a driver 60 as a control means for the actuator. The actuator 40 corresponds to the voice coil motor 10 in FIG. 12, and the driver 60 corresponds to the control device 11 in FIG. 121.

The light from the subject passes through the optical quantity adjusting element arranged on the optical axis Z, then passes through the photographing optical system 499 and enters the image pickup element 500 such as CCD to form a subject image. To do. Then, the light of this image is converted into an electric signal by the image pickup device 500, and the signal is converted into a camera signal processing circuit 50.
At 1, the image signal is converted into a television standard video signal.

The image signal is used by the exposure state discrimination circuit 502 to generate a control signal for controlling each parameter for determining the exposure state such as the exposure time and the incident light amount in order to adjust the image pickup system to an appropriate exposure state.

The control signal for controlling the amount of incident light is ± E
The signal is supplied to the variable ND control circuit 504 in the form of a signal indicating whether to change only V, and is converted into a control voltage for driving the actuator such as the voice coil. The image pickup device 5 is supplied to the control voltage driver 60, and the actuator 40 is driven by current drive by, for example, a VI converter to adjust the distance d between the transparent plates 1 and 2 of the optical amount adjustment device.
The amount of light incident on 00 is adjusted. In this way, the exposure adjustment is executed.

In addition to this, a control signal for adjusting the exposure time is generated by the exposure state determination circuit 502 and supplied to the image sensor control circuit 503 to control the light accumulation time. Specifically, a VO for switching the setting of the electronic shutter of the CCD
Timing control such as a D reset pulse and a read pulse of accumulated charge is executed.

Further, the video signal input to the exposure state determination circuit 502 is output as a television signal and also used for an automatic focusing (AF) mechanism. The focus control circuit 506 determines whether the image signal is in focus or out of focus, and generates a control signal according to the determination of the current focus plane maintenance, front focus, rear focus, etc. A control signal such as a drive pulse is generated at 507, an actuator 508 such as a step motor is driven, and a focus adjustment optical system in the photographing optical system 499 is driven.
In this way, the AF operation is executed using the same signal as the input signal used for the exposure state determination circuit 502.

FIG. 14 is a schematic diagram showing the structure of a video camera as an embodiment of the optical device of the present invention which incorporates the optical quantity adjusting device 50 of FIG. The optical quantity adjusting device 5
Since 0 has already been described in the above embodiment, description thereof will be omitted.

The light from the subject passes through the optical quantity adjusting element arranged on the photographing optical axis Z and the photographing optical system 100 to form a subject image on the image pickup element 500.

The output signal of the image pickup device 500 is converted into a television standard video signal by the camera signal processing circuit 501. The image signal generates a control signal for controlling each parameter of the exposure state determination such as the exposure time and the incident light amount in order to adjust the image pickup system in the exposure state determination circuit 502.

The signal for controlling the amount of incident light is ± what EV
Variable ND control circuit 5 depending on the signal form of changing only
04, and converted into a drive voltage for driving the actuator such as the voice coil. The actuator 40 is supplied to the drive voltage driver 60 and driven by current by, for example, a VI converter to adjust the distance d between the transparent plates 1 and 2 of the optical amount adjusting element to adjust the distance d.
The amount of light incident on 0 is adjusted. The exposure is adjusted in this way.

A pair of transparent plates 1 constituting the optical quantity adjusting element
The distance between 2 and 2 is detected by a position detector 515 such as an encoder attached to the actuator 40, and the distance information is supplied to the image surface correction control circuit 512, and the image surface correction control circuit 512 determines the image surface from the distance information. Correction lens 108
Drive signal of the driver 513 is generated.
The actuator 514 is driven by the driver 513 to move the image plane correction lens 108 to an appropriate position. The details of driving the image plane correction lens 108 will be described later.

In addition to this, a control signal for adjusting the exposure time is generated by the exposure state determination circuit 502 and supplied to the image sensor control circuit 503 to control the light accumulation time of the image sensor 500. Specifically, timing control such as a VOD reset pulse for switching the setting of the electronic shutter of the CCD and a read pulse of accumulated charge is executed.

Further, the video signal input to the exposure state determination circuit 502 is output as a television signal and is also used for an automatic focus adjustment (AF) mechanism. A focus control circuit 505 determines whether the image signal is in focus or out of focus, and the focus lens control circuit 509 outputs the determination information for maintaining the current focus surface, adjusting the front focus, and rear focus. Supply to. The focus lens control circuit 509 generates a control signal according to the adjustment determination information, drives the actuator 511 via the driver 510, and drives the focus lens 107 of the imaging optical system 100. In this way, the exposure state determination circuit 502
The AF operation is executed using the same signal as the input signal used for.

The drive operation of the focus lens when the light amount is adjusted will be described with reference to FIG. If the distance between the pair of transparent plates 1 and 2 forming the optical quantity adjusting element is d, d =
When 0, the object image positions with respect to the image plane correction lens 108 are 0 and I, respectively. The distance from the principal point of the image plane correction lens 108 to the object point is S0, the air-equivalent distance from the principal point of the image plane correction lens 108 to the image point is S0 ′, and L is the image from the principal point of the image plane correction lens 108. S0 ′ = L−D * (1 / n−1) (3) where S is the actual distance to the point, D is the thickness of the pair of transparent plates of the light amount adjusting element, and n is the refractive index of the light amount adjusting element. Here, when the distance between the transparent plates of the optical amount adjusting element is d ≠ 0, the air-converted distance from the principal point of the image plane correction lens 108 to the image point is S ′ = L− (D + d) * (1 / n−1) ) ≠ S0 ′ (4), the object-image relationship with the image plane correction lens 108 is lost, and the image on the image sensor 500 is blurred. Therefore, in order to match the image point with respect to the object point 0 with I, the image plane correction lens 108 is moved by Δx in the optical axis direction. The movement amount Δx at this time is given by f being the focal length of the image plane correction lens 108.

[0063]

[Equation 2]

It is calculated based on

The distance d between the transparent plates of the optical quantity adjusting element is set so that d = 0 when the power is turned on, the encoder 515 for detecting the distance is also initialized to 0, and the image plane correction control circuit 512 also performs optical adjustment. The data Kd, which is the distance between the transparent plates of the quantity adjusting element, is set to an initial value 0 and stored in the memory. In the shooting state, the AF operation and the light amount adjustment operation are started based on the video signal. At this time, when the signal for controlling the incident light amount is supplied in the light amount adjustment and the transparent plate distance d of the optical amount adjusting element changes, the output value Ed = d of the encoder 515 that detects the distance d changes. The image plane correction control circuit 512 compares the detection value Ed supplied from the encoder 515 with the transparent plate interval data Kd of the optical amount adjusting element stored in the memory, and when Ed ≠ Kd, the light amount is adjusted. It is determined that the distance is d = E
The amount of movement of the image plane correction lens with respect to the movement from d to the image plane is calculated based on the equation (5), a control signal for driving the image plane correction lens is supplied to the driver 513, and the encoder value is updated to Kd = Ed. To

FIG. 16 is a schematic view of a video camera as a third embodiment of the optical device of the present invention having the optical quantity adjusting device 50 of FIG.

The video camera of this embodiment has an image surface correction lens and a focus lens in common, and the function of the image surface correction control circuit of the above embodiment is included in the focus lens control circuit 509. State discrimination circuit 50
The incident light quantity control signal for controlling the quantity of incident light generated in 2 is used to correct the image plane accompanying the light quantity adjustment.

Since the incident light amount control signal has a signal form of how many EVs are changed, the change amount Δd of the interval of the transparent plate of the optical amount adjusting element is calculated from this, and the interval d is dnew = dold + Δd (6 ), The drive amount of the focus lens 107 is calculated. In this example, the distance d and the focus lens 1 are
The relationship (FIG. 17) with the drive amount Δx of 07 is stored in the storage device 513 in advance, and the drive amount of the image plane lens is referred from the calculated transparent plate spacing of the optical amount adjustment element by referring to the storage device 513. Then, the control signal for driving the focus lens is supplied to the driver 510 according to the control circuit for driving the focus lens based on the AF operation.

FIG. 18 is a schematic view of a video camera as a fourth embodiment of the optical device of the present invention constructed by using the optical quantity adjusting device of FIG.

This embodiment is an example in which the above-mentioned optical amount adjusting element is used in a rear focus / zoom lens. Reference numeral 106 is a variable magnification lens for changing the magnification, and 107 is compensation for movement of the image plane accompanying movement of the magnification and movement of the object. And a lens (focus lens) that corrects image plane movement due to changes in the distance between the transparent plates of the focus and optical amount adjustment elements. When the distance between the transparent plates 1 and 2 of the optical quantity adjusting element is in the reference state (for example, d = 0), the focus lens 107 moves according to the locus shown in FIG. 19 in order to correct the image plane variation due to the magnification change. To do. The movement locus is determined according to the subject distance s, and information regarding the movement locus is stored in advance in the storage device.

As shown in FIG. 20, when the distance between the transparent plates of the optical quantity adjusting element is in the reference state, the focus lens 107 focused on the object at infinity and the variable magnification lens 106 positioned at the wide end. Based on the respective positions, the positions of the variable power lens 106 and the focus lens 107 in arbitrary states are set as Pv and Pf, respectively.

When the power is turned on, the focus lens 10 is adjusted so that the distance d between the transparent plates of the optical quantity adjusting element becomes d = 0.
7 is at infinity, the zoom lens 106 is at the wide end,
Initially set for each actuator 40 and 52
Encoders 515, 526 and 526 attached to 0 and 525
The output of 527 is also initialized to 0. Also in the focus lens control circuit 509, the data Kd of the interval of the optical amount adjusting element, the variable lens position data Vd, and the focus lens position data Fd are set to the initial value 0 and stored in the memory. In the shooting state, the AF operation and the light amount adjustment operation are started based on the video signal. At this time, in the light amount adjustment, when a signal for controlling the incident light amount is supplied and the distance d of the optical amount adjusting element changes, the output value Ed = d of the encoder 515 that detects the distance d changes. The focus lens control circuit 509 uses the encoder 515.
The detected value Ed supplied from the device is compared with the transparent plate spacing data Kd of the light amount adjusting element stored in the memory, and Ed is compared.
When ≠ Kd, it is determined that the light amount adjustment is performed, and the focus lens movement amount ΔPf with respect to the movement of the image surface is calculated from the equation (5) from the change amount of the interval.

ΔPf = Δx At this time, since the object-image relationship in the focus lens differs depending on the position of the focus lens 107, if the distance between the principal point of the focus lens and the image plane at the reference position is s0 ′,
The distance s ′ between the principal point of the focus lens and the image plane when the focus lens is at an arbitrary position is s ′ = s0 ′ + Pf (7) As a result, the distance to the object point is

[0074]

[Equation 3]

It can be obtained by

The focus lens control circuit 509 supplies the control signal for driving the focus lens based on the calculated drive amount to the driver 516 in accordance with the control signal based on the AF operation, and at the same time, the transparent plate spacing of the optical amount adjusting element. The data Kd and the focus lens position data Pf are updated.

The zooming operation of the zoom lens 106 is performed by the zoom switch 522 generating a zoom instruction signal and supplying it to the zooming control circuit 523. The scaling control circuit 523 generates a drive signal based on the scaling instruction signal so as to drive the scaling lens 106 in a predetermined direction, and drives the actuator 525 via the driver 524 to perform scaling. The position of the variable power lens 106 that moves at this time is detected by an encoder 527 attached to the actuator 525, and the detected variable power lens position Pv is supplied to the focus lens control circuit 509.

The focus lens control circuit 509 calculates the distance s ′ between the principal point of the focus lens and the image plane from the position Pf ′ of the focus lens 107 detected by the encoder 526 attached to the actuator 52 according to the equation (4), The distance s between the principal point of the focus lens and the image plane is calculated from (8), and the distance s between the principal point of the focus lens in the reference state and the image plane is s0 ′ = s′−d * (1 / n−1) ( 9) Calculate the amount ΔPf ′ driven by the light amount adjustment

[0079]

[Equation 4]

It is calculated from

As a result, the position Pf of the focus lens 107 converted into the reference state is calculated as Pf = Pf '+ ΔPf' (11).

The calculated position P of the focus lens 107
A movement locus Lfi (see FIG. 19) of the focus lens is selected from the storage device 519 based on f and the position Pv of the variable power lens 106, and a predetermined focus lens position Pf corresponding to the variable power lens position Pv associated with the variable power is obtained. Then, the amount driven by the light amount adjustment is again corrected to Pf ′ = Pf′−ΔPf ′ (12), and a drive signal based on Pf ″ is generated to drive the actuator 520 via the driver 516.

The drive amounts ΔPf and ΔPf ′ of the focus lens associated with the light amount adjustment may be stored in advance in a storage device.

FIG. 21 is a schematic view of a video camera as an optical device of the present invention constructed by using the optical quantity adjusting device of FIG.

The light from the subject passes through the optical quantity adjusting element arranged on the photographing optical axis Z and the photographing optical system 100 to form a subject image on the image sensor 500.

The output of the image pickup device 500 is converted into a television standard video signal by the camera signal processing circuit 501. The image signal generates a control signal for controlling each parameter of the exposure state determination such as the exposure time and the incident light amount in order to adjust the image pickup system in the exposure state determination circuit 502.

The signal for controlling the amount of incident light is ± EV
The time-division control circuit 52 has a signal form of whether to change only
8 is supplied. The time-division control circuit 528 sends the light amount adjustment control signal to the drive amount Δ in the interval between the transparent plates 1 and 2 of the optical amount adjusting element.
The image plane correction lens 10 at that time is converted into d.
The drive amount Δx of 8 is calculated. These drive amounts Δd and Δx
Are further divided into predetermined drive amounts ΔΔd and ΔΔx, and are supplied to the variable ND control circuit 504 and the image plane correction control circuit 512 as drive information. Variable ND control circuit 504
In (1), the supplied drive information is converted into a drive voltage for driving an actuator such as the voice coil that drives the transparent plate spacing of the light amount adjusting element, and the drive voltage is supplied to the driver 60 of the optical amount adjusting device 50. Then, the actuator 40 is driven by a current drive, for example, by a VI converter, and the distance d between the transparent plates 1 and 2 of the optical amount adjusting element is adjusted. Further, also in the image surface correction control circuit 512, it is converted into a drive voltage for driving the image surface correction lens 108 and supplied to the driver 513, and the image surface correction lens 108 is driven by the actuator 514. The exposure is adjusted in this way. The details of driving the light amount adjusting element and the image plane correction lens 108 will be described later.

In addition to this, a control signal for adjusting the exposure time is generated by the exposure state determination circuit 502 and supplied to the image sensor control circuit 503 to control the light accumulation time of the image sensor 500. Specifically, timing control such as a VOD reset pulse for switching the setting of the electronic shutter of the CCD and a read pulse of accumulated charge is executed.

Further, the video signal input to the exposure state determination circuit 502 is output as a television signal and is also used for an automatic focus adjustment (AF) mechanism. A focus state determination circuit 502 determines whether the video signal is in focus or out of focus, and the focus lens control circuit outputs the determination information for maintaining the current focus surface, adjusting the front focus, rear focus, and the like. 509. The focus lens control circuit 509 generates a control signal according to the adjustment determination information, and the actuator 511 via the driver 510.
To drive the imaging optical system 100 focus lens 107. In this way, the exposure state determination circuit 502
The AF operation is executed using the same signal as the input signal used for.

The driving operation of the image plane correction lens 108 when the light amount is adjusted will be described with reference to FIG. Assuming that the distance between the pair of transparent plates constituting the optical quantity adjusting element is d, d = 0
At this time, the object image positions with respect to the image plane correction lens 108 are 0 and I, respectively. The distance from the principal point of the image plane correction lens 108 to the object point is S0, the air-equivalent distance from the principal point of the image plane correction lens 108 to the image point is S0 ′, and L is the image from the principal point of the image plane correction lens 108. S0 ′ = L−D * (1 / n−1) (3), where n is the air-equivalent distance to the point and n is the refractive index of the light amount adjusting element. Here, when the distance between the transparent plates of the optical amount adjusting element is d ≠ 0, the air-converted distance from the principal point of the image plane correction lens 108 to the image point is S ′ = L− (D + d) * (1 / n−1). ≠ S0 ′ (4), the object-image relationship with the image plane correction lens 108 is lost, and the image on the image sensor 500 is blurred. Therefore, in order to match the image point with respect to the object point 0 with I, the image plane correction lens 108 is moved by Δx in the optical axis direction. Assuming that f is the focal length of the image plane correction lens 108, the movement amount Δx at this time is

[0091]

[Equation 5]

It is calculated based on

The distance between the transparent plates 1 and 2 of the optical quantity adjusting element is calculated from the incident light quantity control signal (Ev) by the amount of change Δd of the distance, and is calculated as dnew = old + Δd (6).

The distance d between the transparent plates 1 and 2 of the optical quantity adjusting element is set so that d = 0 when the power is turned on, and the time division control circuit 528 also sets the transparent plates 1 and 2 of the optical quantity adjusting element to the same value. The interval data Kd is set to an initial value 0. In the shooting state, a control signal for controlling the amount of incident light is supplied to the time division control circuit 528 in adjusting the amount of light. The time division control circuit 528 calculates the driving amount Δd of the transparent plate from the control signal, and calculates the driving amount Δx of the image plane correction lens from the equations (6), (4) and (5).

By the way, in the optical system, there is a size of the point image (allowable circle of confusion δ) that cannot be detected as a blur even if the point image is blurred (FIG. 23).

In this embodiment, in consideration of this, the optical quantity adjusting element and the image plane correcting lens are controlled. That is, the respective movement amounts Δd and Δx are time-divided to the variable ND control circuit 504 and the image plane correction control circuit 512 as the driving information of the driving amounts ΔΔd and ΔΔx so that the blur of the image is driven within the range of the circle of confusion δ. It is supplied alternately. As a result, the optical quantity adjusting element and the image plane correction lens are alternately driven, and by repeating this n times, the light quantity adjustment and the accompanying image plane correction are performed. However, it is INT (Δd / ΔΔd), and INT (X) represents that X is rounded to the first decimal place and converted into an integer value. FIG. 24 is a diagram schematically showing this state.

FIG. 25 is a flow chart showing this operation.

FIGS. 26 and 27 are views for explaining an embodiment in which the driving method of the optical quantity adjusting element and the image plane correction lens is changed in the same configuration as FIG.

In this embodiment, the amount of movement (ΔΔd, ΔΔx) alternately supplied with time is not constant, but as shown in FIG. 26, the image plane is moved from the best focus position to one side ( For example, the drive signal ΔΔds or ΔΔxs of the light amount adjusting element or the image plane correction lens that moves to the permissible circle of confusion on the object side is supplied, and thereafter the image plane is allowed to the other (for example, the image plane side) Drive signal Δ of the light quantity adjustment element and image plane correction lens that moves to the circle of confusion
Δd or ΔΔx is alternately supplied, and this operation is repeated n times to finally supply the drive signal ΔΔde or ΔΔxe for moving the image plane to the best focus position. However,

[0100]

[Equation 6]

FIG. 27 is a flow chart showing this operation. FIG. 28 shows a video camera as an embodiment of the optical device of the present invention constituted by using the two-tandem type optical quantity adjusting device shown in FIG. 3A, for example. The present embodiment differs from the configuration of FIG. 3 in that two actuators and a driver for each actuator are used to drive the two optical quantity adjusting elements of the optical quantity adjusting device. ..

Further, in this embodiment, of the two optical quantity adjusting elements 101 and 102 of the optical quantity adjusting device, the front optical quantity adjusting element 101 is configured as a light quantity adjusting element,
The rear optical quantity adjusting element 102 is configured as an optical path length correcting element, and therefore, in the following description, the element 102 will be referred to as an “optical path length correcting element 102”.

The light quantity adjusting element 101 has a space between the two transparent plates 12 and 13 filled with an opaque fluid M1, while the optical path length correcting element 102 has two transparent plates 1 and 13.
A transparent fluid M2 is filled between 6 and 17.

The light amount adjusting function and the optical path length correcting function in the optical amount adjusting device used in this embodiment will be described below.

Assuming that the changing thickness of the light quantity adjusting element 101 is d and the refractive index of the opaque fluid M1 is n, the changing air-converted thickness of the light quantity adjusting element 101 is 1 = d / n.

On the other hand, when the changing thickness in the optical path length correcting element 102 is d'and the refractive index of the transparent fluid M2 is n ', the changing air-converted thickness of the light quantity adjusting element is 1' = d '/ n'. Become.

When the thickness of the light quantity adjusting element 101 is changed by Δd due to the light quantity adjustment, the air converted thickness is Δ1 = Δd / n.
Change. Since the optical path length correction element 102 changes the interval so as to cancel this variation in the air-converted thickness, Δ1 + Δ1 ′ = 0 Δd / n + Δd ′ / n ′ = 0, and the variation in the interval of the optical path length correction element 102 is Δd. '= -N / n' * Δd.

In the structure shown in the figure, the light from the subject passes through the photographing optical system 100 arranged on the optical axis Z, the light quantity adjusting element 101 and the optical path length correcting element 102, and then the subject image is formed on the image pickup element 500. Image.

The output of the image pickup device 500 is converted into a video signal of the television standard by the camera signal processing circuit 501. The image signal generates a control signal for controlling each parameter of the exposure state determination such as the exposure time and the incident light amount in order to adjust the image pickup system in the exposure state determination circuit 502.

The signal for controlling the amount of incident light is ± EV
Variable ND control circuit 5 depending on the signal form of changing only
04A and 504B, and converted into a drive voltage for driving the actuator such as the voice coil. The drive voltage is supplied to the drivers 529 and 530, and the actuator 531 is current-driven by, for example, a VI converter.
And 532 are driven to adjust the distances d and d ′ between the light amount adjusting element 101 and the transparent plate of the optical path length correcting element 102, and adjust the incident light amount to the image pickup element 500 while keeping the air-equivalent thickness unchanged. The exposure is adjusted in this way.

In addition to this, a control signal for adjusting the exposure time is generated by the exposure state discrimination circuit 502 and supplied to the image sensor control circuit 503 to control the light accumulation time. Specifically, a VO for switching the setting of the electronic shutter of the CCD
Timing control such as a D reset pulse and a read pulse of accumulated charge is executed.

Further, the video signal input to the exposure state determination circuit 502 is output as a television signal, and is also used for an automatic focus adjustment (AF) mechanism. A focus control circuit 506 determines whether the image signal is in focus or out of focus, and generates a control signal according to the determination of the current focus plane maintenance, front focus, rear focus, etc. Actuator 50 via driver 507
8 to drive the focus lens 10 of the imaging optical system 100.
Drive 7 In this way, the exposure state determination circuit 5
The AF operation is executed using the same signal as the input signal used for 02.

FIG. 29 is a simplified version of the configuration of FIG. 28, in which one variable ND control circuit 504 for controlling the drivers 529 and 530 for the optical quantity adjusting device is provided. The description of the operation is omitted.

FIG. 30 is also a simplified version of the configuration of FIG. 28, in which the optical quantity adjusting device has only one actuator 534 and only one control driver 533. In this embodiment, the light amount adjusting element 101 and the optical path length correcting element 102 are the same actuator 534.
Since it can be driven by, the optical quantity adjusting device shown in FIGS. 1 and 3 can be used as it is.

FIG. 31 shows an embodiment of a video camera having only one optical quantity adjusting element and two optical quantity adjusting devices of FIG. 12 arranged in tandem in front of the optical system. The components of the electronic circuit of the embodiment are the same as the components of the embodiment of FIG. (Thus, the description of the circuit is omitted.) In this embodiment, two optical quantity adjusting elements 31 and 3 are used.
It is different from the embodiment of FIG. 30 that both of the two are configured as light quantity adjusting elements.

First optical quantity adjusting element 3 arranged in front
In No. 1, the closed space between the transparent plates 33 and 34 is filled with the first opaque fluid m1 having a low light transmittance per unit thickness, and in the second optical quantity adjusting element 32 arranged at the rear, it is transparent. The closed space between the plates 35 and 36 is filled with a second opaque fluid m2 having a high light transmittance per unit thickness.
In this embodiment, only the front optical quantity adjusting element 31 is driven when the change of the transmitted light quantity is small, and only the rear optical quantity adjusting element 32 is driven when the change of the transmitted light quantity is large.

In FIG. 31, 37 is a flexible cylindrical body which constitutes the peripheral wall of the fluid chamber of the front optical amount adjusting element 31, and 38 is the peripheral wall of the fluid chamber of the rear optical amount adjusting element 32. A flexible tubular body that constitutes the part. The voice coil type actuator 10 shown in FIG. 12 may be used as the actuators 531 and 532, but the transparent plates of the elements 31 and 32 may be axially moved by a rotary motor and a helicoid.

In each of the above-mentioned embodiments, only the case where the non-integrated optical quantity adjusting element is used is shown, but the integrated optical quantity adjusting element of FIGS. 4 to 7 may be used.

The incident light amount detecting means described in the claims corresponds to the exposure state judging circuit 502 in the embodiment relating to the video camera, but the detecting means is a different form of detection from the embodiment. Of course, it may be a means. Further, although the above embodiments relate to the video camera, it is obvious that the present invention is not limited to the video camera and can be applied to various optical devices.

[0120]

Since the optical quantity adjusting device of the present invention is driven by a continuously controllable driving means such as a voice coil type actuator, it can be used in an optical device such as a video camera.

According to the optical quantity adjusting device of the present invention in which at least two optical quantity adjusting elements are arranged in tandem,
Since it is possible to adjust the light amount in a wide range and each optical amount adjusting element can have different functions, it is possible to adjust two or more functions at the same time.

Since the optical amount adjusting device of the present invention can realize a light amount adjusting device which is smaller and has better controllability than the conventional diaphragm blade type light amount adjusting device, according to the present invention, it is possible to perform the light amount adjusting with higher accuracy than the conventional optical device. It is possible to provide a compact optical device capable of adjusting exposure.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an optical quantity adjusting device of the present invention.

FIG. 2 is a diagram showing an operating state of an optical quantity adjusting element of the apparatus shown in FIG.

FIG. 3A is a sectional view of another embodiment of the optical quantity adjusting device of the present invention. FIG. 3B is a view showing a cam cylinder as an example of a driving means of the apparatus of FIG.

FIG. 4 is a cross-sectional view showing an embodiment of an optical quantity adjusting device of the present invention.

FIG. 5 is a cross-sectional view showing an embodiment of the optical quantity adjusting device of the present invention.

FIG. 6 is a cross-sectional view showing an embodiment of the optical quantity adjusting device of the present invention.

FIG. 7 is a cross-sectional view showing an embodiment of the optical quantity adjusting device of the present invention.

8 is a diagram showing an operating state of an optical amount adjusting element of the optical amount adjusting device of FIG.

FIG. 9 is a diagram for explaining the function of an optical amount adjustment element that constitutes the optical amount adjustment device of the present invention.

10 is a diagram showing an example of the relationship between the light transmittance T of a fluid and the distance d between a pair of transparent plates of the optical quantity adjusting element shown in FIG.

FIG. 11 is a view showing an example of the structure of the optical quantity adjusting element.

FIG. 12 is a diagram showing an embodiment of an optical amount adjusting device of the present invention.

13 is a diagram showing an optical system control circuit of a video camera as a first embodiment of the optical device of the present invention configured by using the optical amount adjusting device of FIG.

14 is a diagram showing an optical system control circuit of a video camera of a second embodiment of the optical device of the present invention configured by using the optical amount adjusting device of FIG.

15 is a diagram showing the operation of the optical amount adjustment element in the video camera shown in FIG.

16 is a diagram showing an optical system control circuit of a video camera of a third embodiment of the optical device of the present invention constituted by using the optical quantity adjusting device shown in FIG.

17 is a diagram showing the relationship between the distance d between the transparent plates of the optical amount adjusting element and the focus lens movement amount ΔPf in the video camera of FIG.

18 is a diagram showing an optical system control circuit of a video camera as a fourth embodiment of the optical device of the present invention configured by using the optical amount adjusting device of FIG.

FIG. 19 is a zoom lens 1 in the video camera of FIG.
06 instantaneous position Pv and focus lens 107 instantaneous P
The figure which shows the relationship with f.

20 is a zoom lens 1 in the video camera of FIG.
6 is a diagram showing a state change of 06, the focus lens 107, and the optical amount adjusting element.

21 is a diagram showing an optical system control circuit of a video camera as a fifth embodiment of the optical device of the present invention configured by using the optical amount adjusting device of FIG.

22 is a diagram for explaining the operations of the image plane correction lens 108 and the light amount adjustment element in the video camera of FIG.

FIG. 23 and

FIG. 24 is a diagram for explaining the relationship between the operation of the optical amount adjustment element and the image blur in the video camera of FIG. 21.

25 is a flowchart showing a control operation for driving an optical amount adjustment element (a light amount adjustment element) and an image plane correction lens in the video camera of FIG.

26 is a diagram for explaining the relationship between the operation of the optical amount adjustment element and the image in the video camera of FIG.

27 is a flowchart showing a method of driving the light amount adjustment element and the image plane correction lens for preventing the image from being blurred in the video camera of FIG.

28 is an optical amount adjusting device of FIG. 3 (a) or FIG.
FIG. 6 is a diagram showing an optical system control circuit of a video camera as an embodiment of the optical device of the present invention configured by using the optical quantity adjusting devices (2 pieces).

FIG. 29 is the optical quantity adjusting device of FIG.
FIG. 6 is a diagram showing an optical system control circuit of a video camera as an embodiment of the optical device of the present invention configured by using the optical amount adjusting device of FIG.

30 is a diagram showing an optical system control circuit of a video camera as an embodiment of the optical device of the present invention configured by using the optical amount adjusting device of FIG. 1 or the optical amount adjusting device of FIG.

31 is an optical quantity adjusting device of FIG. 3 (a) or FIG.
The figure which showed the optical system control circuit of the video camera of this invention comprised using either of two optical amount adjusting devices of this.

[Explanation of symbols]

1,2,12,13,16,17,20,21,22 ...
Transparent plate 3, 14, 18 ... Cylindrical body 4, 15, 19,
24, 25 ... Fluid 10 ... Voice coil type actuator 10a ... Moved element 10b ... Coil 101, 102 ... Optical quantity adjusting element 106 ... Magnification lens 107 ... Focus lens 108 ... Image plane correction lens 801 ... Frame body 802 ... Movable member 1001 , 1002 ... Movable part member 1001a, 1002a ... Follower pin 1004 ... Frame body 1005 ... Cam tube

Claims (20)

[Claims] 1. A first and a second transparent plate, which face each other and are spaced apart from each other, and at least one of which is movable back and forth with respect to the other, and a peripheral wall portion of a space between the two transparent plates. A first optical amount adjusting element having a peripheral wall member and a first fluid filled in the space; and a first optical amount adjusting element facing each other and spaced from each other, and at least one of which advances and retracts with respect to the other. A third fluid plate that is movable, a peripheral wall member that forms a peripheral wall portion of a space between the transparent plates, and a second fluid that fills the space. A second optical quantity adjusting element, and at least one driving means for driving the transparent plate of the first and second optical quantity adjusting elements that can move back and forth. The optical quantity adjusting element is characterized in that the optical quantity adjusting elements are arranged front and back on the same optical axis. Apparatus. 2. The optical quantity adjusting device according to claim 1, wherein the light transmittance of the first fluid and the light transmittance of the second fluid are different from each other. 3. The optical quantity adjusting device according to claim 1, wherein the first fluid is an opaque fluid and the second fluid is a transparent fluid. 4. The optical quantity adjusting device according to claim 1, wherein the first optical quantity adjusting element is a light quantity adjusting element, and the second optical quantity adjusting element is an optical path length correcting element. 5. The first optical quantity adjusting element is a light quantity adjusting element, the second optical quantity adjusting element is an optical path length correcting element, and a change in the distance between the transparent plates of the optical path length correcting element is 2. The optical quantity adjusting device according to claim 1, wherein both the elements are driven so as to cancel a change in the distance between the transparent plates of the light quantity adjusting element. 6. A transparent plate of the first optical amount adjusting element, which is movable back and forth, and a transparent plate of the second optical amount adjusting element, which is movable forward and backward, are separately driven. The optical quantity adjusting device according to claim 1, which is characterized in that. 7. The transparent plate of the first optical amount adjusting element, which can move forward and backward, and the transparent plate of the second optical amount adjusting element, which can move forward and backward, are driven at the same time. The optical quantity adjusting device according to claim 1. 8. A first and a second transparent plate, which face each other and are spaced apart from each other, and at least one of which is movable back and forth with respect to the other, and a peripheral wall portion of a space between the two transparent plates. Driving means for arranging at least two optical quantity adjusting elements each having a peripheral wall member and a fluid filled in the space in tandem, and moving the transparent plate of the optical quantity adjusting elements. An optical quantity adjusting device characterized in that. 9. A first transparent plate, a second transparent plate and a third transparent plate which face each other and are spaced apart from each other, and at least one of which is movable back and forth with respect to the other, the first transparent plate and the first transparent plate. A first fluid chamber formed between the second transparent plate, a second fluid chamber formed between the second transparent plate and the third transparent plate, and a first fluid chamber A first fluid filled in the second fluid chamber, a second fluid filled in the second fluid chamber, and drive means for moving at least one of the transparent plates with respect to another transparent plate. Optical quantity adjusting device. 10. The optical quantity adjusting device according to claim 1, wherein said driving means is a voice coil type actuator. 11. A first and a second transparent plate, which face each other and are spaced apart from each other, and at least one of which is movable back and forth with respect to the other, and a peripheral wall portion of a space between the two transparent plates. An optical quantity adjusting device comprising: a peripheral wall member, an opaque fluid filled in the space, and a driving means for driving a transparent plate of the both transparent plates that can move back and forth; An optical system including an adjusting device, an incident light amount detecting means for detecting an incident light amount or an incident light intensity on the optical system, and controlling the driving means of the optical amount adjusting device according to an output of the incident light amount detecting means. An optical device comprising a control means. 12. A first and a second transparent plate which face each other and are spaced apart from each other and at least one of which is movable back and forth with respect to the other, and a peripheral wall portion of a space between the two transparent plates. A light amount adjusting element including a peripheral wall member and an opaque fluid filling the space, an optical system including the light amount adjusting element, and an intensity or a light amount of light incident on the optical system is detected. Incident light amount detecting means, control means for controlling the distance between the transparent plates of the light amount adjusting element according to the output of the incident light amount detecting means, and an image plane for correcting the image plane movement accompanying the operation of the light amount adjusting element. An optical device comprising: a correction unit. 13. The optical device according to claim 12, wherein the image plane correction means is at least one lens group forming the optical system. 14. The optical apparatus according to claim 12, wherein the image plane correction means is a focus lens of the optical system. 15. The optical device according to claim 12, wherein the image plane correction is performed based on information on a distance between the transparent plates of the light quantity adjusting element. 16. A first and a second transparent plate, which face each other and are spaced apart from each other, and at least one of which is movable back and forth with respect to the other, and a peripheral wall portion of a space between the two transparent plates. And a light amount adjusting device including a peripheral wall member, an opaque fluid filled in the space, and a driving unit that drives a transparent plate of the both transparent plates that can move forward and backward, and the light amount adjusting device. An optical system for adjusting the light amount by means of an optical system, an incident light amount detecting means for detecting the intensity or the light amount of light incident on the optical system, and a light amount adjusting device according to the output of the incident light amount detecting means. Control means for controlling the drive means, image plane correction means for correcting the movement of the image plane due to the operation of the light quantity adjustment device, and time division control for time division control of the light quantity adjustment device and the image surface correction means An optical device comprising: 17. The optical device according to claim 16, wherein the image plane correction means is at least one lens group forming the optical system. 18. The optical apparatus according to claim 16, wherein the image plane correction means is a focus lens of the optical system. 19. The optical device according to claim 16, wherein the image plane correction is performed based on information on a distance between the transparent plates of the light amount adjusting device. 20. The optical device according to claim 16, wherein the image plane correction is performed based on exposure control information of the optical system.