JPH10319310A - Autofocusing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-accurate autofocusing device whose speed is high. SOLUTION: As to a pupil stop time division switching mechanism constituting a phase difference detection system autofocusing device; the stopping position of a mask board 5 is controlled by a control member 12 and the attracting surface 9c of an energizing keeping type solenoid 9, and the stopping position of a light shielding blade 8 performing the light shielding of pupil stops 5b and 5c in time-division manner is controlled by a control member 11 and the groove part 5g of the board 5. By this constitution, the board 5 and the blade 8 can highly accurately turn at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an automatic focus adjusting device for performing automatic focus adjustment based on an image signal obtained by an image pickup device such as a CCD.

[0002]

2. Description of the Related Art As one type of conventional automatic focusing apparatus, there is an apparatus having a pupil dividing means. In this method, a pupil dividing unit that divides a photographic light beam of a photographic optical system into at least two regions in a time series, and an optical image formed by photographic light beams that pass through different regions divided by the pupil dividing unit. Focus calculating means for calculating a defocus amount of the photographing optical system from an electric signal obtained by photoelectric conversion by the image pickup device, wherein the pupil dividing means is a disk-shaped mask plate for shielding at least visible light. At least two pupil stops provided symmetrically with respect to the center of the optical axis of the photographing optical system, and light blocking means capable of selectively blocking one of the pupil stops. A motor is provided for driving the mask plate and the light shielding means, and the light shielding blades serving as the light shielding plate and the light shielding means are configured to be rotatable.

In the automatic focus adjustment method of the above-described apparatus, an image signal is formed in time series on the image sensor by the pupil dividing means. In order to minimize the effect, the pupil division operation must be performed at a very high speed.

Further, in the automatic focusing method of the above-described apparatus, an image signal is formed on an image sensor by a photographing light beam divided into at least two regions, and the defocus amount is calculated. In order to minimize the size, at least two holes provided in the mask plate must always be accurately and symmetrically arranged around the optical axis of the photographing optical system.

[0005] The automatic focus adjustment method using the pupil division means described above is a kind of phase difference detection method. The principle of detecting the amount of defocus will be described below with reference to Japanese Patent Application No. 8-633.

FIG. 12 is a diagram showing the principle of this phase difference detection system. In the figure, reference numeral 201 denotes a photographing lens;
Indicates an aperture position of the photographing lens 201, and 20
Reference numeral 3 denotes a focal plane of the photographing lens 201. Also 205
Denotes a light beam, 205a denotes a light beam passing through the area a at the stop position 202, and 205b denotes a light beam passing through the area b at the stop position 202. As can be seen from this figure, when the subject is focused on the focal plane 203 by the photographing lens 201, the area a,
The light beams passing through b coincide with each other on the imaging plane 203. But,
At a position 203 a with respect to the focusing plane 203,
The light beam passing through the areas a and b at the stop position of 01 is 103a
Does not coincide with each other, the corresponding point position is shifted depending on the distance between the areas a and b of the aperture position of the taking lens 201 and the distance between the focusing surfaces 203 and 203a. The phase difference detection method uses this principle to determine the distance X between the centers of the areas a and b of the aperture position of the photographing lens 201 and the respective images formed at the position 203a through the areas a and b. Deviation Y
And the defocus amount Z of the photographing lens is geometrically calculated from the distance L from the aperture surface to the lens 203a. For example, assuming that 203a is the imaging surface in FIG. 12, X: Y = L−Z: Z is obtained, and the defocus amount Z is obtained by the following equation.

[0007]

(Equation 1)

[0008]

However, in the above-mentioned conventional example, there is provided a restricting means for accurately arranging at least two pupil stops provided on the mask plate symmetrically with respect to the center of the optical axis of the photographing optical system. Therefore, even if a stop command is given to the motor to stop the mask plate at a predetermined position, the mask plate is rotated excessively due to the moment of inertia of the mask plate, and the mask plate is accurately stopped at the predetermined position. Can not do. This becomes more noticeable as the speed of the mask plate increases. Therefore, the conventional example is not suitable for speeding up. Although it is possible to use a motor having a driving force that is remarkably strong against the moment of inertia of the mask plate, the size of the motor is large and the space and power are not efficient. It is also conceivable that the mask plate may be inadvertently rotated at the time of impact. Further, in order to retract the pupil aperture, it is indispensable to energize in the retracting direction.

Further, the light shielding means is not desirable for the same reason as described above, since it does not have a regulating means for accurately disposing the light shielding blade in the pupil stop.

The present invention has been made under such circumstances, and has as its object to provide a high-speed and high-precision automatic focusing device.

[0011]

In order to achieve the above object, according to the present invention, an automatic focusing apparatus is provided with the following (1) to (5).
The configuration is as shown in (9).

(1) a mask plate having two pupil stops;
A first method of stopping the rotation of the mask plate at a first rotation position
Position restricting means, a second position restricting means for stopping the rotation of the mask plate at a second rotational position, and the two pupil diaphragms which stop at a first light shielding position and a second light shielding position. , A third position regulating means for stopping the rotation of the light-shielding blade at the first light-shielding position, and stopping the rotation of the light-shielding blade at the second light-shielding position. Fourth
An automatic focus adjustment device comprising: a position regulating means; and a drive source for driving the mask plate and the light shielding blade.

(2) The fourth position restricting means is provided on the mask plate, and the second position restricting means is configured to swing the mask plate when the light shielding blade is restricted by the fourth position restricting means. The automatic focusing device according to the above (1), which has a function of suppressing movement.

(3) The automatic focus adjusting device according to (2), wherein the second position restricting means is an energization holding type solenoid.

(4) The automatic focus adjusting device according to (2), wherein the second position regulating means is a self-holding solenoid.

(5) An urging member for urging the mask plate to rotate in a first direction which is the direction of the second position restricting means, and an urging member for urging the mask plate in a direction opposite to the first direction. The light-shielding blade is rotated in the direction of the first position restricting means, which is the second direction, and the light-shielding blade is rotated in the direction of the fourth position restricting means, which is the second direction. The automatic focus adjustment device according to any one of (1) to (4), further including a driving source configured to rotate in a direction of the third position restricting means, which is the direction of (3).

(6) The driving source is an electromagnetic motor.
Is driven by the sum of the energizing torque in the first energizing direction and the cogging torque. The driving in the second direction is performed until the light shielding blade reaches the fourth position regulating means. (5) The automatic focus adjustment according to (5), wherein the adjustment is performed with the sum of the energizing torque in the second energizing direction opposite to the energizing direction and the cogging torque, and thereafter, the adjustment is performed only with the cogging torque. apparatus.

(7) The rotation of the light-shielding blade in the second direction by the driving source is stopped at the position of the fourth position regulating means.
The automatic focus adjusting device according to the above (6), wherein the stop is performed by the urging by the urging member and the function by the second position regulating means.

(8) The automatic focus according to (7), wherein when starting driving the light shielding blade in the second direction by the driving source, the power supply to the driving source is advanced by a predetermined time corresponding to an operation delay of the light shielding blade. Adjustment device.

(9) The automatic focusing device according to the above (3) or (4), wherein energization of the solenoid is performed during energization of the drive source.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to embodiments of an automatic focusing apparatus.

(Embodiment 1) First, a system configuration of an electronic still camera provided with an "automatic focus adjusting device" of the present embodiment will be described with reference to FIG.

In FIG. 10, reference numeral 101 denotes a photographing optical system to which image light is input, 102 denotes a motor for moving a focus lens and a zoom lens of the photographing optical system 101 and its driver unit, and 103 denotes a pupil aperture time division switching mechanism. A shutter aperture system 104; an imaging signal processing system 104 such as a CCD for converting an image light photoelectrically into a video signal; 105 an A / D converter for digitizing the video signal; and 106 an A / D converter 105 A digital signal processing unit for performing various digital signal processing of the converted digital video signal; 107, a system control unit for the entire camera; 108, a PCMCIA-compliant slot connected to a recording medium, a function card, etc., and its controller unit; Is used to temporarily store digital video signals, for example, DRAM
A reference numeral 110, an electronic viewfinder (EVF), a driver 111 of the EVF 110,
112 is a DA converter for sending an analog signal to the driver unit 111, 113 is a VRAM that holds an image to be displayed on the EVF 110, and outputs a digital signal to the DA converter 112, 114 is camera mode data, etc. , An external monochrome liquid crystal display (EXT.LCD) 115, a controller and a driver for displaying the liquid crystal display 114, and an operation unit 116 outside the camera such as a shutter button and a dial.

When the shutter button of the operation unit 116 is half-pressed (SW1 is turned on), the system control unit 107 detects this, and performs photometry and AF for exposure condition setting.
(Auto focus) operation starts.

The pupil aperture is switched in a time-division manner and exposed, and a correlation operation of each image data stored in the image pickup device is performed.
The amount of defocus is determined, and the focus lens is moved in the optical axis direction based on the amount.

When it is determined that the image plane is in the vicinity of the in-focus state and is in the in-focus plane, the AF operation is terminated, the in-focus state is displayed, the exposure is adjusted, and the photographing standby state, ie, the shutter button is fully pressed (SW2 ON) It becomes possible. When the photographing is performed by pressing the switch SW2, the video signal stored in the image sensor is converted into a digital signal by the AD converter 105, and is recorded on a recording medium (not shown) via the digital signal processing unit 106.

Next, a description will be given of a pupil aperture time-division switching mechanism in the "automatic focus adjusting device" of the present embodiment.

FIG. 1 is an exploded perspective view of a pupil aperture time division switching mechanism which is a main part of the present embodiment. First, each component will be described. In FIG. 1, reference numeral 1 denotes a rotor formed in a cylindrical shape by a two-pole magnet or the like, 2 denotes an arm molded from resin or the like, and one end is provided with an arm pin 2a, and the other end is along the center axis of the rotor. Shaft 2 extending in both directions
The rotor 1 is fixed to the shaft portion 2b side by press-fitting or the like. Reference numeral 3 denotes a stator formed of a ferromagnetic material such as electromagnetic soft iron or silicon steel plate, which is formed to be close to the outer periphery of the rotor 1 and is formed in a straight line for inserting a coil 4 made of a copper wire. Consisting of parts. The coil 4 is provided with input terminals 4a and 4b. The members 1 to 4 are collectively called a drive source. Reference numeral 5 denotes a mask plate obtained by subjecting a cold-rolled steel strip, a specially polished steel strip, or the like to a black plating treatment, and a hole part 5 for rotating and guiding.
a, pupil apertures 5b and 5c for performing pupil time-division exposure,
It is composed of a bent portion 5e, a hole 5f, and a groove 5g. An ND filter 6 is attached to the mask plate 5, which is disposed at the position of the light beam of the photographing optical system when the brightness of the subject is high, and lowers the transmittance of the light amount. Reference numeral 7 denotes an urging member that is connected to the mask plate 5 and urges the rotational movement of the mask plate 5, and has hook portions 7a and 7b.

Reference numeral 8 denotes a light-shielding blade for shielding the pupil diaphragms 5b and 5c of the mask plate 5 in a time-division manner.
b and a hole 8a. Reference numeral 9 denotes an iron core formed of soft magnetic iron or the like, which is provided with mounting holes 9a and 9b, and which has an adsorbing surface 9 for adsorbing the bent portion 5e of the mask plate 5.
c, 9d. 10 is a coil made of copper wire,
It has input terminals 10 a and 10 b and is inserted into the iron core 9. The component consisting of 9 and 10 is generally called an energization holding type solenoid. Reference numeral 11 denotes a stopper that regulates rotation of the arm 2. Reference numeral 12 denotes a stopper that regulates rotation of the mask plate 5. Reference numeral 13 denotes a magnetic detection element such as a Hall element, which can obtain rotation angle information of the rotor 1 and the arm 2 by detecting the amount of magnetic flux of the rotor 1.

Next, the mutual relationship between the components will be described in detail. The shaft portions 2b and 2c of the arm 2 are generally supported by bearings such as a case member and the like so that the rotor 1 and the arm 2 can rotate freely. The stator 3 is similarly fixed to a case member or the like, and the rotor 1 and the stator 3 are positioned and arranged so that the inner peripheral surface of the stator 3 and the outer peripheral surface of the rotor 1 are closely opposed to each other. Further, the magnetic detection element 13 is disposed near the outer peripheral side surface of the rotor 1. A stopper 11 is provided on the case member or the like to restrict the rotation of the arm 2 and the light shielding blade 8 in the CW direction (illustrated in the drawing). The hole 5a of the mask plate 5 is normally fitted with a shaft provided on a base plate member or the like to allow the mask plate 5 to rotate freely. Further, the hook 5a of the urging member 7 is hooked and connected to the hole 5f of the mask 5. Also, a hook 7 of the urging member 7
b is usually hooked and connected to a hole or the like provided in the base plate member or the like. That is, the urging member 7 sets the mask plate 5 to C
It has a biasing force to rotate in the W direction. The side surface of the arm pin 2a is engaged with the groove 5g of the mask plate 5. Therefore, when the arm 2 rotates in the CW direction, the mask plate 5 can also rotate in the CW direction by the urging member 7. The suction surfaces 9c and 9d of the current holding type solenoid are
The arm 2 is attached to a position where the bent portion 5e of the mask plate 5 is attracted before the arm 2 hits the stopper 11 to restrict the rotation of the mask plate 5. The rotational position of the mask plate 5 when the bent portion 5e is attracted to the attracting surfaces 9c and 9d is a position where the pupil diaphragms 5b and 5c are symmetrically arranged around the optical axis. Attachment of the current holding type solenoids (9, 10) is usually fastened to a positioning pin provided on a main plate member or the like by a screw hole. The stopper 12 is connected to the CC of the mask plate 5.
It is provided on a main plate member or the like so as to restrict rotation in the W direction (described in the figure). The position of the stopper 12 is such that the mask plate 5 can be retracted to a position where it does not block the light beam of the imaging optical system. The hole 5a of the light-shielding blade 8 is normally fitted with a shaft provided on a base plate member or the like, so that the light-shielding blade 8 can rotate freely. The arm pin 2a is fitted in the hole 8b, so that the light-shielding blade 8 rotates according to the rotation of the arm 2. It should be noted that the bent portion 5e is provided with the suction surfaces 9c, 9c.
d, the arm pin 2a obtains an angle range in which the arm pin 2a can rotate between the stopper 11 and the groove 5g. The arm pin 2a is attached to each end (stopper 11 and groove 5g) of this angle range. By hitting, the light-shielding blades 8 can alternately shield the respective pupil stops 5b and 5c. That is, the stopper 11 and the groove portion 5g are
Is a position regulating means.

The driving source used in the pupil aperture time-division switching mechanism has the same configuration as that described in Japanese Patent Application Laid-Open No. 6-186613. As described in claim 1, the cogging torque acts to rotate the rotor in one direction in the entire region, and a torque obtained by adding the cogging torque and the energizing torque (hereinafter referred to as output torque) is in the entire region. To rotate the rotor in the other direction. That is, in FIG. 1, the cogging torque τ _c is configured to operate in the CCW direction over the entire operating angle range, and the output torque τ _o is configured to operate in the CW direction over the entire operating angle range.

[0032] Here, the urging torque tau _s of the mask plate 5 by cogging torque tau _c biasing member 7 of the drive source across the operating angle range and take the center of rotation of the drive source and the mask plate 5 coaxially | τ _c |> | τ _s | This aims at saving power of the pupil aperture time-division switching mechanism by rotating the mask plate 5 in the retracting direction and holding the retracting without power supply.

Further, the attraction torque τ _m acting on the mask plate 5 when the bent portion 5e of the mask plate 5 is attracted to the attraction surfaces 9c and 9d, and the arm pin 2 at the time of switching the exposure of the pupil diaphragm.
The impact torque τ _i acting on the mask plate 5 by the impact of “a” on the groove 5g is | τ _m |> | τ _i | when the rotation center of the drive source and the mask plate 5 is coaxial. This is to prevent the mask plate 5 from swinging due to the impact at the time of switching the exposure of the pupil aperture (when the light-shielding blade 8 rotates in the CCW direction and switches the exposure of the pupil aperture). The purpose is to improve the reliability of the time division switching mechanism.

FIG. 2 is a diagram showing a state of the pupil aperture time-division switching mechanism in a non-energized state (a retracted state). In FIG.
Reference numeral 20 denotes an opening which is a passage of a light beam of the photographing optical system, and reference numeral 21 denotes a center of the optical axis. Since the absolute value of the cogging torque of the drive source is larger than the absolute value of the urging torque of the mask plate 5 by the urging member 7 as described above, the mask plate 5 is held against the regulating member 12. Also, the arm pin 2a of the driving source and the light shielding blade 8
g. At this time, the opening 20
Is in a state where nothing is shielded from light by the mask plate 5.

The operation sequence of the pupil aperture time-division switching mechanism having the above configuration will be described with reference to FIGS. 3, 4, and 5 to 7. FIG. 3 is a flowchart of the AF sequence of the automatic focusing device. FIG. 4 is a timing chart of the operation of the drive source, the input source of the fixing means, the drive source, the light-shielding blade, and the mask plate in the pupil aperture time-division switching mechanism (the retracted state is set to 0). Reference numeral 31 denotes an input voltage of a drive source, 32 denotes an input voltage of a current-holding solenoid, 33 denotes an arm rotation angle, 34 denotes a light-shielding blade rotation angle, and 35 denotes a mask plate rotation angle.

A description will be given below by comparing FIG. 3 and FIG.

In FIG. 3, when the shutter button of the electronic still camera is half-pressed (START, SW1 ON), photometry (S101) for setting exposure conditions is performed. Thereafter, the pupil aperture 5 is switched by the pupil aperture time division switching mechanism.
b and 5c are set in the opening 20 (S102). This operation will be described in more detail. When a positive step-like input voltage is applied to the drive source (t _{1 in} FIG. 4), the arm 2 of the drive source rotates until it contacts the regulating member 11. The light-shielding blade 8 is rotated according to the movement of the arm 2, and the mask plate 5 is rotated accordingly. Arm 2 stepwise input voltage is applied (t ₂ in FIG. 4) at the same time energizing hold solenoid and strikes per regulating member 11. Surface subsequent mask plate 5 bent portion 5e is suction surface 9c, adsorbed to 9d, the mask plate 5 is fixed and held (t ₃ in FIG. 4). This state is shown in FIG. In this state, the pupil diaphragm 5b is open.
(Exposure) and 5c are CLOSE (shielded). The magnetic detection element 13 is used as an information source for notifying that the arm 2 has hit the regulating member 11.

When the pupil aperture setting is completed by the above operation,
The exposure from the pupil aperture 5b, the accumulation of the first ranging signal (S103) is performed on the image sensor (between FIG 4t ₃ -t _4).
When the accumulation of the first distance measurement signal is completed, the pupil aperture time-division switching mechanism switches the pupil aperture exposure (S104). This operation will be described in more detail. When one step-like input voltage is applied to the drive source of the pupil aperture time-division switching mechanism in the state of FIG. 5 (t _{4 in} FIG. ₄ ), the arm pin 2 a of the drive source hits the groove 5 f of the mask plate 5. To rotate. The light shielding blade 8 is rotated according to the movement of the arm pin 2a. When the arm pin 2a hits the groove 5f, the pupil diaphragm 5b of the light-shielding blade 8 is closed (shielded) and 5c is opened (exposed) and stops (t in FIG. 4).
₅ ). This state is shown in FIG. Here, focusing on the input voltage 31 to the drive source and the movement 33 (rotation angle) of the arm 2,
As shown in FIG. 8, even when the input voltage 31 to the drive source rises, the arm 2 starts operating with a slight delay due to the influence of the inductance of the coil and the friction of the sliding portion. That is, the actual movement has a delay time Δt in response to the operation command to the drive source. Therefore, if the delay time Δt is estimated in advance and the input voltage is supplied to the drive source by Δt earlier than the time (t _{4 in} FIG. 8) to actually operate, the switching operation can be completed more quickly (FIG. 9, 41: (Input voltage of the driving source, 43: arm rotation angle), the influence of camera shake and image signal shake due to shooting of a moving object can be extremely reduced, and highly accurate focus adjustment can be performed.

When the switching of the pupil aperture exposure (S104) is completed, the exposure from the pupil aperture 5c causes the second image pickup element to move to the image sensor.
Accumulation of ranging signal (S105) is performed (Fig. 4t ₅ -t
₆ ). When the accumulation of the second ranging signal is completed, the first and second
The distance measurement signal comparison calculation and the calculation of the defocus amount are performed by the above-described digital signal processing unit (106 in FIG. 10) (S10).
6). As a result, the digital signal processing unit determines whether or not the camera is in focus (S107). If the camera is not in focus, the required lens drive amount is calculated by the digital signal processing unit, and the system control unit (107 in FIG. 10) focuses. A lens drive command is issued to drive the focus lens (S108). Then, the operation from S102 is performed again. When the focus is determined in S107, the evacuating operation of the mask plate 5 and the light shielding blade 8 or the ND filter setting operation is performed (S109). This operation will be described in more detail. First, in the case of the retreat operation, when the drive source of the pupil aperture time division switching mechanism and the energization of the energization holding type solenoid in the state of FIG. 6 are cut off (t _{6 in} FIG. 4), the suction surfaces 9 c
At the same time when the bent portion 5e of the mask plate 5 separates from 9d,
The cogging torque of the driving source, a mask plate 5 and the light shielding blade 8, the mask plate 5 is stopped and held by pivoted until it hits per regulating member 12 (t ₇ in FIG. 4).

Next, in the case of the ND filter setting operation, the energization of the energization holding type solenoid of the pupil aperture time division switching mechanism in the state of FIG.
Is used for information on the rotation angle of the mask plate 5 engaged with the arm 2 to perform a proportional operation, an integral operation, and a differential operation.
The ND filter 6 is set in the opening 20 by performing D control or the like. This state is shown in FIG.

When the retracting operation of the mask plate 5 and the light shielding blade 8 or the setting operation of the ND filter 6 is completed, the diaphragm blade is driven to obtain a proper exposure at the time of photographing (S11).
0). When the aperture drive according to the appropriate exposure value is completed, the camera enters the shooting standby state, and further depresses the shutter button (SW2 ON) to perform shooting (S111). Then, the image data captured and stored in the image sensor is A-
The data is recorded on the recording medium via the D converter (105 in FIG. 10) and the digital signal processing unit (106 in FIG. 10) (S11).
2), a series of operations ends.

As described above, according to this embodiment,
Restriction member 12 and suction surface 9 of current holding type solenoid
Since the stop position of the mask plate 5 is regulated by c and 9d, and the stop position of the light-shielding blade 8 is regulated by the groove 5f of the mask plate 5 and the regulating member 11, the mask plate 5 and the light-shielding blade 8 are positioned at predetermined positions. Can be stopped accurately,
Further, since the stop positions of the mask plate 5 and the light shielding blade 8 are regulated, the mask plate 5 and the light shielding blade 8 can be rotated at a high speed. Further, since the input to the drive source is advanced in advance in anticipation of the operation delay of the arm 2, the pupil aperture can be switched more quickly.

(Embodiment 2) In Embodiment 1, an energization holding type solenoid is used for the fixing means for suppressing the swing of the mask plate.
With this configuration, it is necessary to keep the power on at all times when the mask plate is attracted, which is not desirable from the viewpoint of power consumption. Therefore, in this embodiment, a self-holding solenoid is used as the fixing means, and the mask plate can be held without electricity when sucked.

FIG. 11 is an exploded perspective view of a pupil aperture time division switching mechanism using a self-holding solenoid. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. 51-5
Reference numeral 4 denotes a so-called self-holding solenoid, which comprises an iron core having suction surfaces 51a and 51b, mounting portions 51c and 51d, coils 52 and 53, and a magnet 54. When the bent portion 5e of the mask plate 5 comes into contact with the attraction surfaces 51a and 51b, the magnetic circuit of the self-holding solenoid is closed and the self-holding solenoid is attracted. When the mask plate 5 is released from the suction surfaces 51a and 51b, a pulse-like applied voltage is supplied to the coils 52 and 53 to generate a magnetic field so as to cancel the magnetic flux from the magnet unit 54 (application timing). Is preferably t ₆ in FIG. 4).

As described above, according to the present embodiment,
The same effect as that of the first embodiment can be obtained, and since the mask plate is suctioned and held without power supply, it is possible to contribute to power saving of the pupil aperture time division switching mechanism.

[0046]

As described above, according to the present invention,
A high-speed and high-precision automatic focusing device can be provided.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a main part of a first embodiment.

FIG. 2 is a diagram showing a retracted state of a pupil aperture time division switching mechanism.

FIG. 3 is a flowchart illustrating the operation of the first embodiment;

FIG. 4 is a timing chart showing the operation of the first embodiment;

FIG. 5 is a diagram showing a state in which a pupil diaphragm 5b is open.

FIG. 6 is a diagram showing a state in which a pupil diaphragm 5c is open.

FIG. 7 is a diagram showing a state of an ND filter set.

FIG. 8 is a diagram showing a relationship between an input voltage of a driving source and a rotation operation of an arm.

FIG. 9 is a diagram showing a relationship between an input voltage of a drive source and a rotation operation of an arm.

FIG. 10 is a diagram showing a configuration of an electronic still camera.

FIG. 11 is an exploded perspective view of a main part of the second embodiment.

FIG. 12 is a diagram showing the principle of a phase difference detection method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotor 2 Arm 3 Stator 5 Mask plate 5b, 5c Pupil stop 5g Groove of mask plate 7 Energizing member 8 Shielding vane 9,10 Current holding solenoid 11,12 Stopper

Claims (9)

[Claims] 1. A mask plate having two pupil stops, first position regulating means for stopping the rotation of the mask plate at a first rotation position, and a second position control means for controlling the rotation of the mask plate to a second rotation position. A second position restricting means for stopping at the rotation position, a light shielding blade stopping at the first light shielding position and the second light shielding position, and sequentially shielding the two pupil apertures one by one; Third position regulating means for stopping the movement at the first light shielding position, fourth position regulating means for stopping the rotation of the light shielding blade at the second light shielding position, the mask plate and the light shielding blade An automatic focus adjustment device comprising a drive source for driving the lens. 2. A fourth position restricting means is provided on the mask plate, and the second position restricting means is configured to oscillate the mask plate when the light shielding blade is restricted by the fourth position restricting means. 2. The automatic focusing apparatus according to claim 1, wherein the automatic focusing apparatus has a function of suppressing the focusing. 3. The automatic focus adjusting device according to claim 2, wherein the second position regulating means is an energization holding type solenoid. 4. The automatic focusing device according to claim 2, wherein the second position regulating means is a self-holding solenoid. 5. An urging member for urging the mask plate to rotate in a first direction which is a direction of the second position regulating means,
The mask plate is rotated in the direction of the first position regulating means which is a second direction opposite to the first direction, and the light-shielding blade is moved in the direction of the fourth position regulating means which is the second direction. And a driving source for rotating the light-shielding blade in a direction of the third position regulating means, which is the first direction. 6. The automatic focusing device according to claim 1. 6. The driving source is an electromagnetic motor, and the driving in the first direction is performed by the sum of the energizing torque and the cogging torque in the first energizing direction, and the driving in the second direction is performed. Until the light-shielding blade reaches the fourth position regulating means, the cogging torque is the sum of the energizing torque in the second energizing direction opposite to the first energizing direction and the cogging torque. 6. The automatic focusing apparatus according to claim 5, wherein the automatic focusing is performed only by the automatic focusing. 7. The rotation of the light-shielding blade in the second direction by the drive source is stopped by the urging by the urging member and the function by the second position restricting means at the position of the fourth position restricting means. 7. The automatic focusing apparatus according to claim 6, wherein: 8. The method according to claim 7, wherein when the light-shielding blade is started to be driven by the drive source in the second direction, the power supply to the drive source is advanced by a predetermined time corresponding to an operation delay of the light-shielding blade. Automatic focus adjustment device. 9. The automatic focusing apparatus according to claim 3, wherein the energization of the solenoid is performed during energization of the drive source.