JP6889334B2 - Lens barrel, imaging device, position detection method and position detection program - Google Patents

Description

The present invention relates to a lens barrel, an image pickup device, a position detection method and a position detection program, and more particularly to a lens barrel, an image pickup device, a position detection method and a position detection program for detecting the position of a movable optical element with a magnetic sensor.

There is known a technique for detecting the position of a movable optical element in a lens barrel using a magnetic sensor such as a Hall sensor or an MR sensor (Magneto Resistance Sensor). However, when a magnetic sensor is used to detect the position of an optical element in a lens barrel with a built-in electromagnetic actuator (an actuator that uses electromagnetic force), the magnetic sensor is affected by magnetism from the actuator (magnetic interference). Therefore, there is a problem that the position detection accuracy is lowered. In order to solve this problem, conventionally, the magnetic sensor and the actuator are sufficiently separated from each other (for example, Patent Document 1 and the like), and a magnetic shielding member is arranged between the magnetic sensor and the actuator (for example, Patent Document 1 and the like). 2 etc.) to prevent the detection accuracy from deteriorating.

International Publication No. 2016/006168 Japanese Unexamined Patent Publication No. 2008-15159

The effect of the electromagnetic actuator on the magnetic sensor depends on the distance between the actuator and the magnetic sensor. Therefore, when the distance between the actuator and the magnetic sensor changes, there is a drawback that the position of the target cannot be detected accurately unless the change in the distance is taken into consideration.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a lens barrel, an image pickup apparatus, a position detection method, and a position detection program capable of accurately detecting the position of a detection target.

The means for solving the above problems are as follows.

(1) Detects a first optical element that is movably supported in a direction parallel to or perpendicular to the optical axis, a first actuator that drives the first optical element, and a magnetic field that changes according to the position of the first optical element. A first unit equipped with a position detection sensor that outputs a signal proportional to the magnitude of the detected magnetic field as a position signal, and a second optical element movably supported in a direction parallel to or perpendicular to the optical axis. A second unit including an electromagnetic second actuator for driving the second optical element, a unit driving unit for relatively moving the first unit and the second unit along the optical axis, and a first unit. A lens barrel including a position signal correction unit that corrects a position signal output from a position detection sensor according to the relative positional relationship between the unit and the second unit.

According to this aspect, when the relative positional relationship between the first unit and the second unit is changed by moving the first unit and the second unit relative to each other along the optical axis, the relative positional relationship (distance relationship). The position signal output from the position detection sensor is corrected according to (synonymous). As a result, the position of the first optical element to be detected can be detected with high accuracy.

When the relative positional relationship between the first unit and the second unit changes, the relative positional relationship between the position detection sensor and the second actuator changes. When the relative positional relationship between the position detection sensor and the second actuator changes, the influence of the magnetism that the position detection sensor receives from the second actuator changes, and the output of the position detection sensor changes. Therefore, even if the relative positional relationship between the first unit and the second unit changes, the relative positional relationship between the first unit and the second unit is changed so that the output characteristics of the position detection sensor do not change. The output of the position detection sensor is corrected accordingly. As a result, even when the relative positional relationship between the first unit and the second unit changes, the position of the first optical element to be detected can be detected with high accuracy. The drive method by the unit drive unit may be manual or electric.

(2) The unit drive unit is the lens barrel according to (1) above, which relatively moves the first unit and the second unit along the optical axis in response to a zoom operation.

According to this aspect, the zoom operation causes the first unit and the second unit to move relatively along the optical axis. That is, the relative positional relationship between the first unit and the second unit changes depending on the zoom operation.

(3) The position signal correction unit corrects the position signal output from the position detection sensor based on the zoom position, and is the lens barrel of the above (2).

When the first unit and the second unit are moved by the zoom operation, the relative positional relationship between the first unit and the second unit is uniquely determined by the zoom position. Therefore, in this embodiment, the output of the position detection sensor is corrected based on the zoom position. As a result, the output of the position detection sensor can be corrected more easily.

(4) The unit drive unit is a lens barrel according to any one of (1) to (3) above, wherein the first unit and the second unit are moved along the optical axis by a cam mechanism.

According to this aspect, the unit drive unit moves the first unit and the second unit along the optical axis by the cam mechanism.

(5) The lens barrel according to any one of (1) to (4) above, wherein the first unit and the second unit are arranged adjacent to each other.

According to this aspect, the first unit and the second unit are arranged adjacent to each other. The influence of magnetism on the position detection sensor from the second actuator increases as the distance between the position detection sensor and the second actuator decreases. Therefore, the present invention works particularly effectively when the first unit and the second unit are arranged adjacent to each other.

(6) The lens barrel according to any one of (1) to (5) above, wherein the position detection sensor is a hall sensor.

According to this aspect, the position detection sensor is composed of a hall sensor. The Hall sensor is one of the magnetic sensors and outputs a signal proportional to the magnitude of the detected magnetic field. Therefore, when the Hall sensor is used as the position detection sensor, the position detection sensor is affected by the magnetism from the second actuator, so that the present invention works effectively.

(7) The lens barrel according to any one of (1) to (6) above, wherein the second actuator is a voice coil motor.

According to this aspect, the second actuator is composed of a voice coil motor. The voice coil motor is one of the electromagnetic actuators, and is an actuator whose main components are a magnet and a coil. Therefore, when a voice coil motor is used for the second actuator, the second actuator affects the detection of the position detection sensor, and thus the present invention works effectively.

(8) The second actuator is a moving magnet type voice coil motor, and the position signal correction unit is based on the relative positional relationship between the first unit and the second unit and the position of the second optical element. The lens barrel of (7) above that corrects the position signal output from the position detection sensor.

According to this aspect, the second actuator is composed of a moving magnet type voice coil motor. The moving magnet type voice coil motor is a type of voice coil motor in which the magnet moves in the magnetic field created by the yoke and the coil. Therefore, in this case, the second optical element, which is a movable component, is provided with a magnet. When the second actuator is a moving magnet type voice coil motor, the magnet moves, so it is necessary to correct the output of the position detection sensor in consideration of the position of the magnet. Therefore, in this embodiment, the output of the position detection sensor is corrected according to the relative positional relationship between the first unit and the second unit and the position of the second optical element, which is the position of the magnet. As a result, the position of the first optical element to be detected can be detected with high accuracy.

(9) The position signal correction unit further corrects the position signal based on the mounting position and / or the mounting posture of the position detection sensor, which is any one of the above (1) to (8).

The output of the position detection sensor also changes depending on the mounting position and mounting posture of the position detection sensor. According to this aspect, the output of the position detection sensor is corrected based on the mounting position and / or the mounting posture of the position detection sensor. As a result, the position of the first optical element to be detected can be detected more accurately.

(10) The lens barrel according to any one of (1) to (9) above, further comprising a temperature sensor, and the position signal correction unit further corrects the position signal based on the temperature detected by the temperature sensor.

The output of the position detection sensor also changes depending on the temperature of the surrounding environment. According to this aspect, the output of the position detection sensor is corrected based on the temperature detected by the temperature sensor. As a result, the position of the first optical element to be detected can be detected more accurately.

(11) Based on the position signal output from the position detection sensor when the first optical element is positioned at the calibration reference position, the information necessary for correcting the position signal based on the temperature is acquired. ) Lens barrel.

According to this aspect, the information necessary for correcting the position signal based on the temperature is acquired based on the position signal output from the position detection sensor when the first optical element is positioned at the calibration reference position. As a result, the information (particularly, the offset amount) necessary for correcting the position signal based on the temperature can be easily acquired. As the calibration reference position, for example, one movable end of the first optical element (one end of the movable range) can be adopted.

(12) The position signal correction unit corrects the position signal based on the temperature detected by the temperature sensor when the temperature detected by the temperature sensor exceeds a predetermined allowable range (10). Or the lens barrel of (11).

According to this aspect, the temperature-based correction is performed only when the temperature detected by the temperature sensor exceeds a predetermined allowable range. As a result, the temperature-based correction is performed only when the correction is really necessary, so that the overall processing load can be reduced.

(13) The second unit is a lens barrel according to any one of (1) to (12) above, further including a second optical element position detecting unit for detecting the position of the second optical element.

According to this aspect, the second unit is provided with a second optical element position detecting unit that detects the position of the second optical element. As a result, the position of the second optical element in the second unit can be detected.

(14) The second optical element position detecting unit includes an origin detecting unit that detects the movement of the second optical element to a predetermined origin and a displacement amount detecting unit that detects the displacement amount of the second optical element. The lens barrel of (13) above.

According to this aspect, the second optical element position detecting unit has an origin detecting unit and a displacement amount detecting unit. The origin detection unit detects the movement of the second optical element to a predetermined origin. The displacement amount detecting unit detects the displacement amount of the second optical element from the origin. The second optical element position detection unit detects that the second optical element is located at the origin by the origin detection unit, and detects the displacement amount of the second optical element from the origin by the displacement amount detection unit. The position of the optical element (position relative to the origin) is detected.

(15) The displacement amount detecting unit is the lens barrel of the above (14), which is composed of an MR sensor.

According to this aspect, the displacement amount detecting unit is composed of an MR sensor (Magneto Resistance Sensor).

(16) In the first unit, the lens which is the first optical element is moved parallel to the optical axis to correct curvature of field, and in the second unit, the lens which is the second optical element is made parallel to the optical axis. The lens barrel according to any one of (1) to (15) above, which is moved to adjust the focus.

According to this aspect, in the first unit, curvature of field is corrected by moving the lens, which is the first optical element, in parallel with the optical axis. Further, in the second unit, the focus is adjusted by moving the lens, which is the second optical element, in parallel with the optical axis.

(17) An imaging device provided with a lens barrel according to any one of (1) to (16) above.

According to this aspect, the lens barrel of the image pickup apparatus is provided with the lens barrel according to any one of (1) to (16) above.

(18) A movable lens supported so as to be movable in a direction parallel to or perpendicular to the optical axis, a first actuator for driving the movable lens, and a magnetic field that changes according to the position of the movable lens are detected, and the detected magnetic field An imaging lens including a movable unit including a position detection sensor that outputs a signal proportional to the magnitude as a position signal, a movable unit drive unit that moves the movable unit along an optical axis, and an optical axis. Relative positional relationship between an image sensor that is movably supported in orthogonal directions and captures an optical image of a subject via an imaging lens, an electromagnetic second actuator that drives the image sensor, and a movable unit and an image sensor. An imaging device including a position signal correction unit that corrects a position signal output from a position detection sensor according to the above.

According to this aspect, when the relative positional relationship between the movable unit and the image sensor is changed by moving the movable unit relative to the optical axis, the position is changed according to the relative positional relationship. The position signal output from the detection sensor is corrected. As a result, the position of the movable lens to be detected can be detected with high accuracy.

(19) The image pickup apparatus according to (18) above, wherein the movable unit drive unit moves the movable unit along the optical axis in response to a zoom operation.

According to this aspect, the movable unit moves relatively along the optical axis by the zoom operation. That is, the relative positional relationship between the movable unit and the image sensor changes depending on the zoom operation.

(20) The position signal correction unit is a position signal correction unit that corrects a position signal output from a position detection sensor based on a zoom position, and the image pickup apparatus according to (19) above.

When the movable unit is moved by the zoom operation, the relative positional relationship between the movable unit and the image sensor is uniquely determined by the zoom position. Therefore, in this embodiment, the output of the position detection sensor is corrected based on the zoom position. As a result, the output of the position detection sensor can be corrected more easily.

(21) Detects a first optical element that is movably supported in a direction parallel to or perpendicular to the optical axis, a first actuator that drives the first optical element, and a magnetic field that changes according to the position of the first optical element. A first unit equipped with a position detection sensor that outputs a signal proportional to the magnitude of the detected magnetic field as a position signal, and a second optic that is movably supported in a direction parallel to or perpendicular to the optical axis. A second unit including an element and an electromagnetic second actuator for driving a second optical element is used as a position signal output from a position detection sensor in a lens barrel that moves relatively along an optical axis. Based on this, it is a position detection method for detecting the position of the first optical element, and provides information on the relative positional relationship between the step of acquiring the position signal output from the position detection sensor and the first unit and the second unit. A position detection method including a step of acquiring and a step of correcting a position signal output from a position detection sensor according to the relative positional relationship between the first unit and the second unit.

According to this aspect, when the first unit provided with the position detection sensor and the second unit provided with the electromagnetic actuator (second actuator) move relatively along the optical axis, the first unit Information on the relative positional relationship between the unit and the second unit is acquired, and the output of the position detection sensor is corrected based on the acquired positional relationship information. As a result, even when the relative positional relationship between the first unit and the second unit changes, the position of the first optical element to be detected can be detected with high accuracy.

(22) A movable lens supported so as to be movable in a direction parallel to or perpendicular to the optical axis, a first actuator for driving the movable lens, and a magnetic field that changes according to the position of the movable lens are detected, and the detected magnetic field An image pickup lens equipped with a position detection sensor that outputs a signal proportional to the magnitude as a position signal, a movable unit drive unit that moves the movable unit along the optical axis, and an optical axis. In an imaging device provided with an image sensor that is movably supported in orthogonal directions and captures an optical image of a subject via an imaging lens and an electromagnetic second actuator that drives the image sensor, from a position detection sensor. It is a position detection method that detects the position of the movable unit based on the output position signal, and is the relative positional relationship between the step of acquiring the position signal output from the position detection sensor and the movable unit and the image sensor. A position detection method including a step of acquiring information and a step of correcting a position signal output from the position detection sensor according to the relative positional relationship between the movable unit and the image sensor.

According to this aspect, when the movable unit provided with the position detection sensor moves relative to the image sensor driven by the electromagnetic actuator (second actuator), the movable unit and the image sensor are relative to each other. Information on the positional relationship is acquired, and the output of the position detection sensor is corrected based on the acquired positional relationship information. As a result, even when the relative positional relationship between the movable unit and the image sensor changes, the position of the movable lens to be detected can be detected with high accuracy.

(23) Detects a first optical element that is movably supported in a direction parallel to or perpendicular to the optical axis, a first actuator that drives the first optical element, and a magnetic field that changes according to the position of the first optical element. A first unit equipped with a position detection sensor that outputs a signal proportional to the magnitude of the detected magnetic field as a position signal, and a second optic that is movably supported in a direction parallel to or perpendicular to the optical axis. A second unit including an element and an electromagnetic second actuator for driving a second optical element is used as a position signal output from a position detection sensor in a lens barrel that moves relatively along an optical axis. Based on this, it is a position detection program that causes a computer to execute a process of detecting the position of the first optical element, and is a step of acquiring a position signal output from a position detection sensor and a relative of the first unit and the second unit. A position detection program including a step of acquiring information on the positional relationship and a step of correcting a position signal output from the position detection sensor according to the relative positional relationship between the first unit and the second unit.

According to this aspect, when the first unit provided with the position detection sensor and the second unit provided with the electromagnetic actuator (second actuator) move relatively along the optical axis, the first unit Information on the relative positional relationship between the unit and the second unit is acquired, and the output of the position detection sensor is corrected based on the acquired positional relationship information. As a result, even when the relative positional relationship between the first unit and the second unit changes, the position of the first optical element to be detected can be detected with high accuracy.

(24) A movable lens that is movably supported in a direction parallel to or perpendicular to the optical axis, a first actuator that drives the movable lens, and a magnetic field that changes according to the position of the movable lens are detected, and the detected magnetic field An image pickup lens equipped with a position detection sensor that outputs a signal proportional to the magnitude as a position signal, a movable unit drive unit that moves the movable unit along an optical axis, and an optical axis. In an imaging device provided with an image sensor that is movably supported in orthogonal directions and captures an optical image of a subject via an imaging lens and an electromagnetic second actuator that drives the image sensor, from a position detection sensor. It is a position detection program that causes a computer to execute a process of detecting the position of a movable unit based on the output position signal. A position detection program including a step of acquiring information on a relative positional relationship and a step of correcting a position signal output from the position detection sensor according to the relative positional relationship of the movable unit and the image sensor.

According to this aspect, when the movable unit provided with the position detection sensor moves relative to the image sensor driven by the electromagnetic actuator (second actuator), the movable unit and the image sensor are relative to each other. Information on the positional relationship is acquired, and the output of the position detection sensor is corrected based on the acquired positional relationship information. As a result, even when the relative positional relationship between the movable unit and the image sensor changes, the position of the movable lens to be detected can be detected with high accuracy.

According to the present invention, the position of the detection target can be detected with high accuracy.

Top view showing an embodiment of an interchangeable lens to which the present invention is applied. Rear view of the interchangeable lens shown in FIG. 3-3 cross-sectional view of FIG. 2 when zooming to the wide end 4-4 sectional view of FIG. 2 when zooming to the wide end 4-4 sectional view of FIG. 2 when zooming to the telephoto end 6-6 sectional view of FIG. 7-7 sectional view of FIG. The figure which shows the moving state of each lens group at the time of a zoom operation Cross-sectional view showing the support structure of the 3rd lens group movable holding frame and the 4th lens group movable holding frame. Cross-sectional view showing the mounting structure of the front group drive actuator of the third lens group Cross-sectional view showing the mounting structure of the fourth lens group drive actuator Block diagram showing the electrical configuration of the interchangeable lens The figure which shows typically the positional relationship between the 3rd lens group and the 4th lens group at a wide end. The figure which shows typically the positional relationship between the 3rd lens group and the 4th lens group at the telephoto end. A graph showing the relationship between the position of the front group of the third lens group and the output value of the position detection sensor. A block of the configuration related to the position detection process of the front group of the third lens group including the correction of the output of the position detection sensor. A flowchart showing the procedure of the position detection process of the front group of the third lens group including the correction of the output of the position detection sensor. Flow chart showing the procedure of drive control processing of the third lens group front group The figure which shows the mounting state of the position detection sensor when it is properly mounted. The figure which shows the mounting state of the position detection sensor when it is mounted improperly. A graph showing the relationship between the position of the front group of the third lens group at a certain zoom position and the output value of the position detection sensor. Block diagram of the configuration related to the position detection process of the front group of the third lens group when the output of the position detection sensor is corrected based on the temperature. Conceptual diagram of how to obtain the correction coefficient of the intercept based on temperature A cross-sectional view showing a schematic configuration of an interchangeable lens when the fourth lens group drive actuator is composed of a moving magnet type VCM. Block diagram of the configuration related to the position detection process of the front group of the third lens group including the correction of the output of the position detection sensor A flowchart showing the procedure of the position detection process of the front group of the third lens group including the correction of the output of the position detection sensor. Cross-sectional view showing an example of a lens barrel provided with a lens that moves in a direction perpendicular to the optical axis and a lens that moves in a direction parallel to the optical axis. 28-28 sectional view of FIG. 27 29-29 sectional view of FIG. 27 Schematic configuration diagram of an imaging device to which the present invention is applied 31-31 sectional view of FIG. 30 32-32 sectional view of FIG. 30 Block diagram of the output correction function of the focus lens position detection sensor provided by the control unit of the image pickup device Flow chart showing the procedure of the focus lens position detection process including the correction of the output of the focus lens position detection sensor.

Hereinafter, preferred embodiments for carrying out the present invention will be described in detail in accordance with the accompanying drawings.

[First Embodiment]
Here, a case where the present invention is applied to an interchangeable lens of an interchangeable lens camera will be described as an example. This type of interchangeable lens is detachably attached to the camera body via a mount.

FIG. 1 is a plan view showing an embodiment of an interchangeable lens to which the present invention is applied. FIG. 2 is a rear view (viewed from the mount side) of the interchangeable lens shown in FIG. FIG. 3 is a 3-3 cross-sectional view of FIG. 2 when the zoom operation is performed to the wide end. FIG. 4 is a 4-4 cross-sectional view of FIG. 2 when the zoom operation is performed to the wide end. FIG. 5 is a 4-4 cross-sectional view of FIG. 2 when the zoom operation is performed to the telephoto end. FIG. 6 is a cross-sectional view taken along the line 6-6 of FIG. FIG. 7 is a cross-sectional view taken along the line 7-7 of FIG.

The interchangeable lens 1 of the present embodiment is a so-called zoom lens, and the focal length is continuously changed by a manual zoom operation. The interchangeable lens 1 includes a lens barrel body 10 to which the lens is assembled and an exterior body 2 that covers the outer periphery of the lens barrel body 10.

[Exterior body]
The exterior body 2 has a cylindrical shape, accommodates the lens barrel body 10 inside, and covers the outer periphery of the lens barrel body 10. The exterior body 2 is provided with a focus ring 3 which is a focus operation member, a zoom ring 4 which is a zoom operation member, and an aperture ring 5 which is an aperture operation member. The focus of the interchangeable lens 1 is manually adjusted by rotating the focus ring 3. Further, by rotating the zoom ring 4, the focal length continuously changes within a predetermined range. Further, by rotating the aperture ring 5, the aperture value (F value) can be switched in a predetermined step.

[Lens barrel body]
The lens barrel body 10 is an example of a lens barrel. The lens barrel body 10 has a fixed cylinder 12 and a cam cylinder 14. The cam cylinder 14 is fitted to the inner peripheral portion of the fixed cylinder 12, and the inner peripheral portion of the fixed cylinder 12 is rotatably held in the circumferential direction.

The fixed cylinder 12 has a mount 16 at its rear end (end on the image plane side). The mount 16 is composed of a so-called bayonet mount.

The cam cylinder 14 is connected to the zoom ring 4 via a connecting member (not shown). Therefore, when the zoom ring 4 is rotated, the cam cylinder 14 also rotates in conjunction with the rotation.

[Lens configuration]
A plurality of lenses are arranged inside the fixed cylinder 12. Specifically, the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 are arranged in order from the object side along the optical axis Z. .. Each lens group is composed of at least one lens.

Further, a diaphragm St is arranged inside the fixed cylinder 12. The aperture St is arranged between the first lens group G1 and the second lens group G2.

FIG. 8 is a diagram showing a moving state of each lens group when the zoom operation is performed. In the figure, (A) shows the lens arrangement at the wide end, and (B) shows the lens arrangement at the tele end. The curves indicated by the symbols AL1 to AL4 indicate the movement locus of the lens group that moves by the zoom operation. Specifically, the reference numeral AL1 is the movement locus of the first lens group G1, the reference numeral AL2 is the movement locus of the second lens group G2, the reference numeral AL3 is the movement locus of the third lens group G3, and the reference numeral AL4 is the fourth lens group G4. It shows the movement trajectory.

As shown in FIG. 8, the first lens group G1 to the fourth lens group G4 are lens groups that move with respect to the image plane Sim by the zoom operation. On the other hand, the fifth lens group G5 is a lens group fixed with respect to the image plane Sim by the zoom operation. The aperture St moves integrally with the second lens group G2.

As shown in FIG. 8, the third lens group G3 is composed of a third lens group front group G3a and a third lens group rear group G3b. The third lens group front group G3a is a lens group for correcting curvature of field, and corrects curvature of field by moving along the optical axis Z. Therefore, the third lens group front group G3a is configured to be movable independently of the other lens groups.

Further, the fourth lens group G4 is a lens group for adjusting the focus, and adjusts the focus by moving along the optical axis Z. Therefore, the fourth lens group G4 is configured to be movable independently of the other lens groups.

The movement of each lens group by the zoom operation is realized by the cam mechanism. The cam mechanism converts the rotation of the cam cylinder 14 into a linear motion to move each lens group along the optical axis Z. In the interchangeable lens 1 of the present embodiment, the cam mechanism is composed of a fixed cylinder 12 having a straight groove, a cam cylinder 14 having a cam groove, and a cam follower provided in a holding frame of each lens group. The lens. Each lens group of the first lens group G1 to the fourth lens group G4 moves along a predetermined movement locus AL1 to AL4 by a cam mechanism. The cam mechanism is an example of a unit drive unit.

[Holding structure of each lens group]
[First lens group]
As shown in FIGS. 3, 4 and 5, the first lens group G1 is held by the first lens group holding frame 20 and arranged in the fixed cylinder 12, and the optical axis Z in the fixed cylinder 12. It is movably supported in the direction parallel to.

The first lens group holding frame 20 is provided with three first lens group zoom drive cam followers 32 on the outer peripheral portion thereof. The three first lens group zoom drive cam followers 32 are arranged at equal intervals in the circumferential direction. Each first lens group zoom drive cam follower 32 fits into the first lens group zoom drive cam groove 14A provided in the cam cylinder 14 and the first lens group zoom drive straight groove 12A provided in the fixed cylinder 12, respectively. It is combined.

With the above configuration, the first lens group G1 is held in the fixed cylinder 12. Further, when the cam cylinder 14 is rotated by the zoom ring 4, the first lens group G1 moves along the optical axis Z in the fixed cylinder 12 by the action of the cam mechanism.

[Second lens group]
As shown in FIGS. 3, 4 and 5, the second lens group G2 is held by the second lens group holding frame 22 and arranged in the fixed cylinder 12, and the optical axis Z in the fixed cylinder 12. It is movably supported in the direction parallel to.

The second lens group holding frame 22 is provided with three second lens group zoom drive cam followers 34 on the outer peripheral portion thereof. The three second lens group zoom drive cam followers 34 are arranged at equal intervals in the circumferential direction. Each second lens group zoom drive cam follower 34 fits into the second lens group zoom drive cam groove 14B provided in the cam cylinder 14 and the second lens group zoom drive straight groove 12B provided in the fixed cylinder 12, respectively. It is combined.

With the above configuration, the second lens group G2 is held in the fixed cylinder 12. Further, when the cam cylinder 14 is rotated by the zoom ring 4, the second lens group G2 moves along the optical axis Z in the fixed cylinder 12 by the action of the cam mechanism.

As shown in FIGS. 3, 4, and 5, the diaphragm unit 30 constituting the diaphragm St is assembled to the second lens group holding frame 22. As a result, the diaphragm St is arranged in the fixed cylinder 12 and moves together with the second lens group G2.

[Third lens group]
As shown in FIGS. 3, 4, 5, and 6, the third lens group G3 is held by the third lens group holding frame 24, arranged in the fixed cylinder 12, and inside the fixed cylinder 12. It is movably supported in a direction parallel to the optical axis Z.

The third lens group holding frame 24 is composed of a third lens group base holding frame 24A and a third lens group movable holding frame 24B held by the third lens group base holding frame 24A. The third lens group movable holding frame 24B is arranged in the third lens group base holding frame 24A, and is movably supported in the third lens group base holding frame 24A in a direction parallel to the optical axis Z. The third lens group front group G3a is held by the third lens group movable holding frame 24B. The rear group G3b of the third lens group is held by the third lens group base holding frame 24A.

The third lens group base holding frame 24A is provided with three third lens group zoom drive cam followers 36 on the outer peripheral portion thereof. The three third lens group zoom drive cam followers 36 are arranged at equal intervals in the circumferential direction. Each third lens group zoom drive cam follower 36 fits into the third lens group zoom drive cam groove 14C provided in the cam cylinder 14 and the third lens group zoom drive straight groove 12C provided in the fixed cylinder 12, respectively. It is combined. As a result, the third lens group base holding frame 24A is held in the fixed cylinder 12. Further, when the cam cylinder 14 is rotated by the zoom ring 4, the third lens group base holding frame 24A moves in the fixed cylinder 12 along the optical axis Z.

A first main shaft 48 and a first sub-shaft 50 are provided in the third lens group base holding frame 24A. The first main shaft 48 and the first sub-axis 50 are respectively arranged along the optical axis Z (see FIG. 3). Further, the first main shaft 48 and the first sub-shaft 50 are arranged at positions facing each other with the optical axis Z interposed therebetween (see FIG. 6). More specifically, it is arranged on a straight line passing through the optical axis Z in a cross section orthogonal to the optical axis Z.

The third lens group movable holding frame 24B includes a first main guide portion 52 that slides along the first main shaft 48 and a first sub guide portion 54 that slides along the first sub shaft 50. The third lens group movable holding frame 24B is slidably supported by the first main shaft 48 and the first sub shaft 50 via the first main guide portion 52 and the first sub guide portion 54.

FIG. 9 is a cross-sectional view showing a support structure of the third lens group movable holding frame and the fourth lens group movable holding frame.

As shown in the figure, the first main guide portion 52 has a tubular shape and has sliding portions 52A at both ends in the axial direction thereof. The sliding portion 52A has an inner diameter corresponding to the outer diameter of the first spindle 48. In the first main guide portion 52, the sliding portions 52A at both ends slide along the first main shaft 48.

The first sub-guide portion 54 has a U-shaped groove portion 54A at its tip. The first sub-guide portion 54 slides along the first sub-shaft 50 by fitting the first sub-shaft 50 into the groove portion 54A.

In the third lens group movable holding frame 24B, the first main guide portion 52 is slidably supported by the first main shaft 48, and the first sub guide portion 54 is slidably supported by the first sub shaft 50. As a result, the lens group base holding frame 24A is movably supported along the optical axis Z.

The third lens group movable holding frame 24B moves along the optical axis Z in the third lens group base holding frame 24A by being driven by the third lens group front group driving actuator 56. The third lens group front group drive actuator 56 is an example of the first actuator. Further, the third lens group front group G3a is an example of the first optical element.

The third lens group front group drive actuator 56 is composed of a moving magnet type (movable magnet type) voice coil motor (VCM). The moving magnet type VCM is a type of VCM in which the magnet moves in the magnetic field created by the yoke and the coil. The VCM is one of the electromagnetic actuators using electromagnetic force. The third lens group movable holding frame 24B is provided with a plurality of driving magnets 56A and a plurality of inner yokes 56B configured by the moving magnet type VCM. Further, the third lens group base holding frame 24A is provided with a driving coil 56C constituting a moving magnet type VCM and a plurality of outer yokes 56D.

FIG. 10 is a cross-sectional view showing a mounting structure of a third lens group front group drive actuator.

As shown in the figure, the drive coil 56C is wound so as to surround the outer peripheral portion of the third lens group movable holding frame 24B, and is attached to the inner peripheral portion of the third lens group base holding frame 24A. The third lens group movable holding frame 24B moves inside the driving coil 56C along the optical axis Z.

The plurality of driving magnets 56A are grouped and arranged in two groups. Specifically, the two groups are arranged symmetrically with respect to the straight line L passing through the optical axis Z in a cross section orthogonal to the optical axis Z. The first main shaft 48 and the first sub-shaft 50 are arranged on the straight line L. Therefore, the two groups of the driving magnets 56A are symmetrically arranged with respect to the straight line L passing through the first main shaft 48 and the first sub-shaft 50.

In the present embodiment, six drive magnets 56A are provided, and the six drive magnets 56A are arranged in two groups. Therefore, each group is provided with three driving magnets 56A. The driving magnets 56A of each group are arranged at equal intervals along the peripheral surface of the third lens group movable holding frame 24B.

The plurality of inner yokes 56B are arranged corresponding to the driving magnets 56A. Each inner yoke 56B is integrated with the corresponding drive magnet 56A and attached to the third lens group movable holding frame 24B.

The plurality of outer yokes 56D are arranged corresponding to the plurality of inner yokes 56B. Each outer yoke 56D is arranged so as to face the corresponding inner yoke 56B with the drive coil 56C interposed therebetween.

With the above configuration, the third lens group G3 is held in the fixed cylinder 12. Further, when the cam cylinder 14 is rotated by the zoom ring 4, the third lens group G3 moves along the optical axis Z in the fixed cylinder 12 by the action of the cam mechanism. That is, the front group G3a of the third lens group and the rear group G3b of the third lens group integrally move in the fixed cylinder 12 along the optical axis Z. Further, when the third lens group front group drive actuator 56 is driven, the third lens group front group G3a moves independently along the optical axis Z. The curvature of field is corrected by moving the third lens group front group G3a alone by the third lens group front group drive actuator 56.

[4th lens group]
As shown in FIGS. 3, 4, 5, and 7, the fourth lens group G4 is held by the fourth lens group holding frame 26, arranged in the fixed cylinder 12, and inside the fixed cylinder 12. It is movably supported in a direction parallel to the optical axis Z.

The fourth lens group holding frame 26 is composed of a fourth lens group base holding frame 26A and a fourth lens group movable holding frame 26B held by the fourth lens group base holding frame 26A. The fourth lens group movable holding frame 26B is arranged in the fourth lens group base holding frame 26A, and is movably supported in the fourth lens group base holding frame 26A in a direction parallel to the optical axis Z. The fourth lens group G4 is held by the fourth lens group movable holding frame 26B.

The fourth lens group base holding frame 26A is provided with three fourth lens group zoom drive cam followers 38 on the outer peripheral portion thereof. The three fourth lens group zoom drive cam followers 38 are arranged at equal intervals in the circumferential direction. Each fourth lens group zoom drive cam follower 38 fits into the fourth lens group zoom drive cam groove 14D provided in the cam cylinder 14 and the fourth lens group zoom drive straight groove 12D provided in the fixed cylinder 12, respectively. It is combined. As a result, the fourth lens group base holding frame 26A is held in the fixed cylinder 12. Further, when the cam cylinder 14 is rotated by the zoom ring 4, the fourth lens group base holding frame 26A moves in the fixed cylinder 12 along the optical axis Z.

A second main shaft 58 and a second sub-shaft 60 are provided in the fourth lens group base holding frame 26A. The second main shaft 58 and the second sub-axis 60 are respectively arranged along the optical axis Z (see FIG. 3). Further, the second main shaft 58 and the second sub-shaft 60 are arranged at positions facing each other with the optical axis Z interposed therebetween (see FIG. 7). Further, the second main shaft 58 is arranged at the same position as the first main shaft 48 in the circumferential direction of the circle centered on the optical axis Z. Therefore, the second main shaft 58 and the second sub-axis 60 are arranged on the same straight line as the first main shaft 48 and the first sub-axis 50 in the cross section orthogonal to the optical axis Z. In addition, "same" here includes a range recognized as substantially the same.

The fourth lens group movable holding frame 26B includes a second main guide portion 62 that slides along the second main shaft 58 and a second sub guide portion 64 that slides along the second sub shaft 60. The fourth lens group movable holding frame 26B is slidably supported by the second main shaft 58 and the second sub shaft 60 via the second main guide portion 62 and the second sub guide portion 64.

As shown in FIG. 9, the second main guide portion 62 has a tubular shape and has sliding portions 62A at both ends in the axial direction thereof. The sliding portion 62A has an inner diameter corresponding to the outer diameter of the second main shaft 58. In the second main guide portion 62, the sliding portions 62A at both ends slide along the second main shaft 58.

The second sub-guide portion 64 has a U-shaped groove portion 64A at the tip thereof. In the second sub-guide portion 64, the groove portion 64A slides along the second sub-shaft 60.

In the fourth lens group movable holding frame 26B, the second main guide portion 62 is slidably supported by the second main shaft 58, and the second sub guide portion 64 is slidably supported by the second sub shaft 60. As a result, the lens group base holding frame 26A is movably supported along the optical axis Z.

The fourth lens group movable holding frame 26B is driven by a plurality of fourth lens group drive actuators 68. The fourth lens group drive actuator 68 is an example of the second actuator. The fourth lens group G4 is an example of the second optical element.

Each fourth lens group drive actuator 68 is composed of a moving coil type (movable coil type) voice coil motor (VCM) 68. The moving coil type VCM is a type of VCM in which only the coil moves in the magnetic field created by the magnet. As described above, the VCM is one of the electromagnetic actuators utilizing the electromagnetic force.

FIG. 11 is a cross-sectional view showing a mounting structure of the fourth lens group drive actuator.

The plurality of fourth lens group drive actuators 68 are grouped and arranged in two groups. Specifically, the two groups are arranged symmetrically with respect to the straight line L passing through the optical axis Z in a cross section orthogonal to the optical axis Z. The second main shaft 58 and the second sub-shaft 60 are arranged on the straight line L. Therefore, the two groups are symmetrically arranged with respect to the straight line L passing through the second spindle 58 and the second layshaft 60.

In the present embodiment, four fourth lens group drive actuators 68 are provided, and four fourth lens group drive actuators 68 are grouped and arranged in two groups. Therefore, each group includes two fourth lens group drive actuators 68. In each group, the two fourth lens group drive actuators 68 are arranged at predetermined intervals along the peripheral surface of the fourth lens group movable holding frame 26B.

Each fourth lens group drive actuator 68 includes a drive coil 68A, a drive magnet 68B, an inner yoke 68C, and an outer yoke 68D.

The drive coil 68A of each fourth lens group drive actuator 68 is attached to the fourth lens group movable holding frame 26B. The fourth lens group movable holding frame 26B has a coil holding portion 70 on the outer peripheral portion thereof, and the driving coil 68A of each fourth lens group driving actuator 68 is held by the coil holding portion 70.

The inner yoke 68C and the outer yoke 68D of the fourth lens group drive actuator 68 are arranged so as to face each other with the drive coil 68A interposed therebetween. The inner yoke 68C and the outer yoke 68D are integrally formed. The inner yoke 68C and the outer yoke 68D integrally configured are arranged at predetermined positions by holding the portion of the outer yoke 68D on the inner peripheral portion of the fourth lens group base holding frame 26A.

The drive magnet 68B of each fourth lens group drive actuator 68 is attached to the inside of the outer yoke 56D and is arranged at a predetermined position. The drive magnet 68B of each fourth lens group drive actuator 68 is an example of a plurality of second drive magnets.

With the above configuration, the fourth lens group G4 is held in the fixed cylinder 12. Further, when the cam cylinder 14 is rotated by the zoom ring 4, the fourth lens group G4 moves along the optical axis Z in the fixed cylinder 12 by the action of the cam mechanism. Further, when the fourth lens group drive actuator 68 is driven, the fourth lens group G4 moves independently along the optical axis Z. Focus adjustment is performed by moving the fourth lens group G4 alone by the fourth lens group drive actuator 68.

[Fifth lens group]
As shown in FIGS. 3, 4 and 5, the fifth lens group G5 is held by the fifth lens group holding frame 28 and arranged in the fixed cylinder 12.

[Position detection structure of each lens group]
[Position of each lens group by zoom operation]
By the zoom operation, each lens group of the first lens group G1 to the fourth lens group G4 moves along a predetermined movement locus AL1 to AL4 (see FIG. 6). Therefore, the relative positional relationship (distance relationship) of each lens group by the zoom operation is known.

[Position detection of 3rd lens group front group G3a and 4th lens group G4]
The front group G3a of the third lens group and the fourth lens group G4 can move independently of the other lens groups. Therefore, the positions of the third lens group front group G3a and the fourth lens group G4 are separately detected. The position of the third lens group front group G3a is detected by the third lens group front group position detection unit 80, and the position of the fourth lens group G4 is detected by the fourth lens group position detection unit 90. ..

[Third lens group front group position detector]
The third lens group front group position detection unit 80 detects the position of the third lens group movable holding frame 24B within the third lens group base holding frame 24A, and detects the position of the third lens group front group G3a. .. More specifically, the position of the third lens group movable holding frame 24B with respect to the reference position set in the third lens group base holding frame 24A is detected, and the position of the third lens group front group G3a with respect to the reference position. Is detected.

As shown in FIGS. 3 and 9, the third lens group front group position detection unit 80 detects the positions of the position detection magnet 82 provided in the third lens group movable holding frame 24B and the position detection magnet 82. It is composed of a position detection sensor 84 and a position detection sensor 84. In particular, in the present embodiment, the position detection sensor 84 is composed of a hall sensor which is a magnetic sensor. The position detection sensor 84 composed of a hall sensor detects a magnetic field that changes according to the position of the position detection magnet 82, and outputs a signal proportional to the magnitude of the detected magnetic field as a position signal.

The position detection sensor 84 is provided in the third lens group base holding frame 24A. As shown in FIGS. 6 and 10, the position detection sensor 84 is arranged at the installation position of the first sub-axis 50 in a cross section orthogonal to the optical axis Z. More specifically, it is arranged on a straight line L passing through the optical axis Z and the first sub-axis 50. Further, as shown in FIGS. 3 and 9, the position detection sensor 84 is arranged behind the first sub-axis 50 (on the image plane side) in a cross section parallel to the optical axis Z.

The position detection magnet 82 is provided on the third lens group movable holding frame 24B. The position detection magnet 82 is arranged close to the position detection sensor 84. Specifically, as shown in FIGS. 3 and 9, in a cross section orthogonal to the optical axis Z, the first sub-guide portion 54 is arranged at the installation position and faces the position detection sensor 84 with a predetermined gap. Is placed. As a result, the position detection magnet 82 and the position detection sensor 84 are both arranged on a straight line L passing through the optical axis Z and the first sub-axis 50 in a cross section orthogonal to the optical axis Z.

According to the third lens group front group position detection unit 80 having the above configuration, the position of the position detection magnet 82 provided on the third lens group movable holding frame 24B is detected by the position detection sensor 84 to obtain a third lens group. The position of the lens group front group G3a is detected.

[Fourth lens group position detector]
The fourth lens group position detection unit 90 detects the position of the fourth lens group movable holding frame 26B in the fourth lens group base holding frame 26A, and detects the position of the fourth lens group G4. More specifically, the position of the fourth lens group movable holding frame 26B with respect to the origin set in the fourth lens group base holding frame 26A is detected, and the position of the fourth lens group G4 with respect to the origin is detected. The fourth lens group position detection unit 90 is an example of the second optical element position detection unit.

The fourth lens group position detection unit 90 includes an origin detection unit 92 that detects that the fourth lens group G4 is located at the origin, and a displacement amount detection unit 94 that detects the displacement amount of the fourth lens group G4. Will be done. The fourth lens group position detection unit 90 detects that the fourth lens group G4 is located at the origin by the origin detection unit 92, detects the displacement amount from the origin by the displacement amount detection unit 94, and then detects the fourth lens group. The position of G4 is detected.

As shown in FIGS. 7 and 11, the origin detection unit 92 includes a light-shielding plate 92A and a photo interrupter 92B. The light-shielding plate 92A is provided on the first main guide portion 52, and the photo interrupter 92B is provided on the fourth lens group base holding frame 26A. The origin detection unit 92 detects that the fourth lens group G4 is located at the origin by detecting the light-shielding plate 92A by the photo interrupter 92B (by detecting the light-shielding by the light-shielding plate 92A, the fourth lens group G4. Detects that is located at the origin.). Therefore, the light-shielding plate 92A and the photo interrupter 92B are installed so that the light-shielding plate 92A is detected at the timing when the fourth lens group G4 is located at the origin (the light-shielding plate 92A is installed at the timing when the fourth lens group G4 is located at the origin). The 92A is installed so as to block the photo interrupter 92B).

As shown in FIGS. 3, 7, and 11, the displacement amount detecting unit 94 is an MR sensor (Magneto Resistive Sensor) that detects the magnetic scale 94A and the north and south poles of the magnetic scale 94A. It is composed of 94B and. The MR sensor 94B is one of the magnetic sensors.

The magnetic scale 94A has a bar shape, and has a structure in which the north and south poles are magnetized at a constant pitch along the longitudinal direction thereof. The magnetic scale 94A is provided in the second main guide portion 62 and is arranged along the moving direction of the fourth lens group G4. That is, it is arranged along the optical axis Z.

The MR sensor 94B is provided in the fourth lens group base holding frame 26A. The MR sensor 94B is arranged in close proximity to the magnetic scale 94A. More specifically, as shown in FIG. 11, in a cross section orthogonal to the optical axis Z, the second main guide portion 62 is arranged at the installation position and is arranged so as to face the magnetic scale 94A with a predetermined gap. Orthogonal. As a result, the magnetic scale 94A and the MR sensor 94B are both arranged on a straight line L passing through the optical axis Z and the second main axis 58 in a cross section orthogonal to the optical axis Z.

According to the fourth lens group position detection unit 90 having the above configuration, the fourth lens group G4 is located at the origin by detecting the light-shielding plate 92A provided in the second main guide unit 62 with the photo interrupter 92B. Is detected. Further, by detecting the displacement amount of the second main guide portion 62 with the MR sensor 94B via the magnetic scale 94A, the displacement amount of the fourth lens group G4 is detected. The position of the fourth lens group G4 with respect to the origin is detected by detecting that the fourth lens group G4 is located at the origin with the photo interrupter 92B and detecting the amount of displacement from the origin with the MR sensor 94B.

[Layout of drive system for sensors]
As described above, the position detection sensor 84 is arranged at the position of the first sub-axis 50 in the cross section orthogonal to the optical axis Z (see FIG. 10). Further, the MR sensor 94B is arranged at the position of the second main guide portion 62 in the cross section orthogonal to the optical axis Z. The position of the second main guide portion 62 is the position of the second main shaft 58 (see FIG. 11). The first spindle 48 and the first sub-axis 50 and the second spindle 58 and the second sub-axis 60 are arranged on a straight line L passing through the optical axis Z in a cross section orthogonal to the optical axis Z. Therefore, the position detection sensor 84 and the MR sensor 94B are arranged on a straight line L passing through the optical axis Z in a cross section orthogonal to the optical axis Z.

On the other hand, in the third lens group front group drive actuator 56 that drives the third lens group front group G3a, a plurality of drive magnets 56A, a plurality of inner yokes 56B, and a plurality of outer yokes 56D, which are constituent elements thereof, form an optical axis. In a cross section orthogonal to Z, it is arranged symmetrically with respect to a straight line L passing through the optical axis Z (see FIG. 10). That is, the elements constituting the magnetic material are arranged symmetrically with respect to the straight line L passing through the optical axis Z in the cross section orthogonal to the optical axis Z.

Further, the plurality of fourth lens group drive actuators 68 for driving the fourth lens group G4 are arranged symmetrically with respect to the straight line L passing through the optical axis Z in a cross section orthogonal to the optical axis Z (see FIG. 10). ). Also in this case, the elements constituting the magnetic material are arranged symmetrically with respect to the straight line L passing through the optical axis Z in the cross section orthogonal to the optical axis Z.

As described above, in the interchangeable lens 1 of the present embodiment, the elements constituting the magnetic body are arranged symmetrically with respect to the position detection sensor 84 and the MR sensor 94B in the cross section orthogonal to the optical axis Z. As a result, the influence of each sensor on the magnetic material can be made uniform, and more accurate detection becomes possible.

Further, in the interchangeable lens 1 of the present embodiment, the first spindle 48 and the first sub-spindle 50 are arranged on the inner diameter side of the second spindle 58 and the second sub-spindle 60. As a result, it is possible to stably support a movable lens group in a compact configuration. That is, by arranging the positions of the first spindle 48 and the first sub-spindle 50 with respect to the second spindle 58 and the second sub-spindle 60 in the radial direction, the size in the optical axis direction is increased as a whole. Without this, the lengths of the first spindle 48 and the second spindle 58 can be secured. Thereby, the front group G3a of the third lens group and the fourth lens group G4 can be stably supported. That is, by increasing the lengths of the first main shaft 48 and the second main shaft 58, the lengths of the first main guide portion 52 and the second main guide portion 62 can be increased, and the third lens group front group G3a and the fourth lens can be increased. Group G4 can be supported stably.

Even when the magnetic material is symmetrically arranged with respect to each sensor as described above, if the positional relationship with the magnetic material changes, the detection accuracy is lowered due to the influence of the change. .. In particular, since the Hall sensor is configured to detect the absolute position, if the positional relationship with the magnetic material changes, the detection accuracy is lowered due to the influence of the change. In the interchangeable lens 1 of the present embodiment, the positional relationship between the position detection sensor 84, which is a hall sensor, and the fourth lens group drive actuator 68 changes depending on the zoom. Therefore, the output of the position detection sensor 84 is corrected according to the change in the positional relationship due to the zoom. This point will be described in detail later.

[Electrical configuration of interchangeable lens]
FIG. 12 is a block diagram showing the electrical configuration of the interchangeable lens.

The interchangeable lens 1 includes a third lens group front group driving unit 110 that drives the third lens group front group G3a, a third lens group front group position detecting unit 80 that detects the position of the third lens group front group G3a, and a fourth lens group. The fourth lens group drive unit 112 that drives the lens group G4, the fourth lens group position detection unit 90 that detects the position of the fourth lens group G4, the aperture drive unit 114 that drives the aperture St, and the temperature inside the interchangeable lens are detected. Controls the overall operation of the temperature detection unit 116, the focus operation detection unit 118 that detects the focus operation, the zoom position detection unit 120 that detects the zoom position, the aperture setting detection unit 122 that detects the aperture setting, and the interchangeable lens 1. The lens control unit 100 is provided.

The third lens group front group drive unit 110 includes a third lens group front group drive actuator 56 and a drive circuit thereof. The third lens group front group drive unit 110 drives the third lens group front group drive actuator 56 in response to a command from the lens control unit 100, and moves the third lens group front group G3a along the optical axis Z. Let me.

The third lens group front group position detection unit 80 includes a position detection sensor 84, and the position detection sensor 84 detects the position of the position detection magnet 82 provided on the third lens group movable holding frame 24B to detect the position of the position detection magnet 82. The position of the front group G3a of the three lens groups is detected. The position here is a position with respect to a reference position set in the third lens group base holding frame 24A. The position detection sensor 84 composed of a hall sensor detects a magnetic field that changes according to the position of the position detection magnet 82, and a signal proportional to the magnitude of the detected magnetic field is a position signal of the third lens group front group G3a. Is output to the lens control unit 100. The lens control unit 100 processes the signal output from the position detection sensor 84 to detect the position of the third lens group front group G3a. At this time, the position of the third lens group front group G3a is detected by performing processing in consideration of the positional relationship between the position detection sensor 84 and the fourth lens group drive actuator 68.

The fourth lens group drive unit 112 includes a plurality of fourth lens group drive actuators 68 and a drive circuit thereof. The fourth lens group drive unit 112 drives each fourth lens group drive actuator 68 in response to a command from the lens control unit 100, and moves the fourth lens group G4 along the optical axis Z.

The fourth lens group position detection unit 90 includes an origin detection unit 92 and a displacement amount detection unit 94. The origin detection unit 92 includes a photo interrupter 92B and detects that the fourth lens group G4 is located at the origin. Further, the displacement amount detection unit 94 includes an MR sensor 94B and detects the displacement amount of the fourth lens group G4. The origin detection unit 92 detects that the fourth lens group G4 is located at the origin, and the displacement amount detection unit 94 detects the displacement amount from the origin, thereby detecting the position of the fourth lens group G4.

The diaphragm drive unit 114 includes a diaphragm drive actuator (not shown) for driving the diaphragm St, and a drive circuit thereof. The diaphragm drive actuator is composed of, for example, a step motor. The aperture drive unit 114 drives the aperture drive actuator in response to a command from the lens control unit 100 to expand or contract the aperture St.

The temperature detection unit 116 includes a temperature sensor (not shown), and the temperature sensor detects the temperature inside the interchangeable lens. The temperature sensor is provided in, for example, the diaphragm unit 30. The temperature detection unit 116 outputs the temperature information in the interchangeable lens detected by the temperature sensor to the lens control unit 100.

The focus operation detection unit 118 detects the amount of rotation operation of the focus ring 3 and outputs the detection result to the lens control unit 100. The lens control unit 100 detects the focus operation amount based on the output from the focus operation detection unit 118.

The zoom position detection unit 120 detects the set position of the zoom ring 4 and outputs the detection result to the lens control unit 100. The lens control unit 100 detects the zoom position (focal length set value) based on the output from the zoom position detection unit 120.

The aperture setting detection unit 122 detects the set position of the aperture ring 5 and outputs the detection result to the lens control unit 100. The lens control unit 100 detects the set aperture value (F value) based on the output from the aperture setting detection unit 122. The aperture value that can be set includes auto, and when auto is selected, the aperture value is set based on an instruction from the camera body.

The lens control unit 100 controls the operation of each unit based on the operations of the focus ring 3, the zoom ring 4, and the aperture ring 5. Specifically, when the manual focus is set, the fourth lens group drive actuator 68 is driven and the fourth lens group G4 is moved based on the rotation operation amount of the focus ring 3. At this time, the fourth lens group G4 is moved based on the position of the fourth lens group G4 detected by the fourth lens group position detection unit 90.

Further, the third lens group front group drive actuator 56 and the fourth lens group drive actuator 68 are driven based on the zoom position changed by the operation of the zoom ring 4, and the third lens group front group G3a and the fourth lens group G4 are driven. To a predetermined position. At this time, the third lens group front group G3a is moved to a predetermined position based on the position of the third lens group front group G3a detected by the third lens group front group position detection unit 80. Further, the fourth lens group G4 is moved to a predetermined position based on the position of the fourth lens group G4 detected by the fourth lens group position detection unit 90.

Further, the aperture drive unit 114 is driven to operate the aperture St based on the aperture value switched by the operation of the aperture ring 5.

Further, the lens control unit 100 controls the operation of each unit in response to a command from the camera to which the interchangeable lens 1 is mounted. For example, based on the autofocus information from the camera, the fourth lens group drive actuator 68 is driven to move the fourth lens group G4 to a predetermined position. Further, based on the aperture setting information from the camera, the aperture drive unit 114 is driven to operate the aperture St.

The lens control unit 100 communicates with the camera control unit 130 of the camera and receives a drive command of each unit from the camera control unit 130. Further, zoom setting information, aperture setting information, focus position information, and the like are transmitted to the camera control unit 130. Communication between the lens control unit 100 and the camera control unit 130 is performed via the terminal 16A provided on the mount 16 (see FIG. 2).

Further, the lens control unit 100 drives the third lens group front group drive actuator 56 based on the temperature detected by the temperature sensor, and moves the third lens group front group G3a to a predetermined position. As a result, the curvature of field caused by the temperature change is corrected.

The lens control unit 100 is composed of, for example, a computer equipped with a CPU (CPU: Central Processing Unit), a ROM (ROM: Read Only Memory), and a RAM (RAM: Random Access Memory), and by executing a predetermined program. , Realize various control functions.

[Correction of position detection sensor output]
FIG. 13 is a diagram schematically showing the positional relationship between the third lens group and the fourth lens group at the wide end, and FIG. 14 is a diagram showing the positional relationship between the third lens group and the fourth lens group at the telephoto end. It is a figure which shows typically.

The third lens group G3 and the fourth lens group G4 are lens groups adjacent to each other. Further, the third lens group G3 and the fourth lens group G4 are both lens groups that move by zoom operation. However, the amount of movement by zooming is different from each other. Therefore, the relative positional relationship between the third lens group G3 and the fourth lens group G4 changes depending on the zoom operation. Specifically, the position gradually changes from the wide end toward the tele end (see FIG. 8). Therefore, the third lens group G3 and the fourth lens group G4 are closest to each other at the wide end (see FIG. 13) and farthest from each other at the telephoto end (see FIG. 14).

By changing the relative positional relationship between the third lens group G3 and the fourth lens group G4, the position detection sensor 84 provided in the third lens group holding frame 24 and the fourth lens group holding frame 26 are provided. The positional relationship with the fourth lens group drive actuator 68 also changes. As a result, the influence of the magnetism that the position detection sensor 84 receives from the fourth lens group drive actuator 68 changes, and the output characteristics of the position detection sensor 84 change.

FIG. 15 is a graph showing the relationship between the position of the front group of the third lens group and the output value of the position detection sensor. The vertical axis shows the position of the front group G3a of the third lens group, and the horizontal axis shows the output value of the position detection sensor 84.

In the figure, the graph shown by the solid line Wa shows the relationship between the position of the third lens group front group G3a at a certain zoom position a and the output value of the position detection sensor 84. Further, the graph shown by the broken line Wb shows the relationship between the position of the third lens group front group G3a at a certain zoom position b and the output value of the position detection sensor 84.

As shown in the figure, the position detection sensor 84 outputs a signal corresponding to the position of the front group G3a of the third lens group. That is, a signal having a voltage corresponding to the position is output as a position signal. On the other hand, the output characteristics of the position detection sensor 84 change when the zoom position changes. That is, even if the actual position of the front group G3a of the third lens group is the same, the output value changes depending on the zoom position. Therefore, in the interchangeable lens 1 of the present embodiment, the output of the position detection sensor 84 is corrected according to the zoom position. This process will be described below.

In the interchangeable lens 1 of the present embodiment, the third lens group G3, the third lens group front group drive actuator 56, and the position detection sensor 84 constitute one unit based on the third lens group holding frame 24. Then, this unit moves in parallel with the optical axis Z by the zoom operation. Further, the 4th lens group G4, the 4th lens group drive actuator 68, and the 4th lens group position detection unit 90 form one unit with reference to the 4th lens group holding frame 26, and this unit is operated by zooming. It moves parallel to the optical axis Z. The unit based on the third lens group holding frame 24 is an example of the first unit, and the unit based on the fourth lens group holding frame 26 is an example of the second unit.

[Structure related to position detection processing of the front group of the third lens group including correction of the output of the position detection sensor]
FIG. 16 is a block diagram of a configuration related to the position detection process of the front group of the third lens group including the correction of the output of the position detection sensor.

The lens control unit 100 performs the position detection process of the third lens group front group G3a including the correction of the output of the position detection sensor 84.

The lens control unit 100 includes a position signal acquisition unit 140 that acquires a position signal by executing a predetermined control program (position detection program), a position signal correction unit 142 that corrects the acquired position signal, and a corrected position signal correction unit 142. The function of the position calculation unit 144 that calculates the position of the front group G3a of the third lens group based on the position signal is realized.

The position signal acquisition unit 140 acquires a signal output from the position detection sensor 84 as a position signal. As the position signal, a signal having a voltage value corresponding to the position is acquired.

The position signal correction unit 142 corrects the position signal acquired by the position signal acquisition unit 140 based on the zoom position. The position signal correction unit 142 acquires zoom position information from the zoom position detection unit 120, and acquires correction coefficient information corresponding to the acquired zoom position from the correction information storage unit 146. Then, the position signal is corrected based on the acquired correction coefficient.

Here, a method of calculating the correction coefficient and a correction of the output of the position detection sensor 84 based on the calculated correction coefficient will be described with reference to FIG.

Assuming that the output value (position signal) of the position detection sensor 84 is x and the position of the third lens group front group G3a is y, the third lens group front group G3a at the zoom position a (solid line graph Wa in FIG. 15) The position of can be approximated as y = A (a) x + B (a). Further, the position of the third lens group front group G3a at the zoom position b (graph Wb, a ≠ b of the broken line in FIG. 15) can be approximated to y = A (b) x + B (b). Here, A (a) is the inclination (sensor output sensitivity) in the case of the zoom position a, and B (a) is the intercept (sensor output bias) in the case of the zoom position a. Further, A (b) is an inclination (sensor output sensitivity) in the case of the zoom position b, and B (b) is an intercept (sensor output bias) in the case of the zoom position b.

Assuming that the output of the position detection sensor 84 at the zoom position a is used as the reference output, the output value at each zoom position is corrected so as to match the output value at the zoom position a. That is, at the same position, the output value of the position detection sensor 84 at each zoom position is corrected so that the output value is the same.

In the case of the zoom position b, if α = A (a) / A (b) and β = [B (a) -B (b)] / A (b), the output value of the corrected position detection sensor 84 ( The position signal) X can be calculated by the function F (x) = αx + β.

Here, α and β are correction coefficients, and the function F (x) = αx + β is a correction function. The correction coefficients α and β are obtained in advance for each zoom position, are associated with the zoom position information, and are stored in the correction information storage unit 146. The correction information storage unit 146 is composed of a ROM of a computer that constitutes the lens control unit 100.

Since the positional relationship between the position detection sensor 84 and the fourth lens group drive actuator 68 is uniquely determined by the zoom position, the position detection sensor 84 and the fourth lens group drive are substantially driven by acquiring the zoom position information. Information on the positional relationship with the actuator 68 (synonymous with the positional relationship between the first unit and the second unit) is acquired.

The position signal correction unit 142 acquires information on the correction coefficients α and β according to the zoom position from the correction information storage unit 146, and sets a correction function F (x) = αx + β based on the acquired correction coefficients α and β. , Correct the position signal x.

The position calculation unit 144 calculates the position of the third lens group front group G3a based on the corrected position signal X. As a result, the correct position can be detected regardless of the zoom position.

[Procedure for detecting the position of the front group of the third lens group including the correction of the output of the position detection sensor]
FIG. 17 is a flowchart showing a procedure (position detection method) of the position detection process of the front group of the third lens group including the correction of the output of the position detection sensor.

First, the position signal x output from the position detection sensor 84 is acquired (step S1). Next, information on the current zoom position is acquired from the zoom position detection unit 120 (step S2). Next, the correction coefficients α and β corresponding to the zoom position are acquired (step S3). Next, the correction function F (x) = αx + β is set based on the acquired correction coefficients α and β, and the position signal x is corrected (step S4). Next, the position of the third lens group front group G3a is calculated based on the corrected position signal X (step S5). As a result, the position of the front group G3a of the third lens group can be obtained.

By correcting the output of the position detection sensor 84 according to the zoom position in this way, the position of the front group G3a of the third lens group can always be accurately detected.

[Drive control of the front group of the 3rd lens group]
FIG. 18 is a flowchart showing a procedure for processing drive control of the front group of the third lens group.

First, a target position as a movement destination is set (step S11). As described above, the third lens group front group G3a is driven by the zoom operation and the temperature change. Therefore, the target position is set based on the zoom position and the temperature.

When the target position is set, the current position information of the third lens group front group G3a is acquired (step S12). The current location information acquisition method is as described above. That is, the output of the position detection sensor 84 is corrected based on the zoom position, and the position is detected based on the corrected output.

Next, the drive amount of the third lens group front group drive actuator 56 required to move from the current position to the target position is calculated (step S13). Next, the third lens group front group drive actuator 56 is driven based on the calculated drive amount (step S14). Next, the current position information of the third lens group front group G3a is acquired (step S15). Then, based on the acquired position information, it is determined whether or not the target position has been reached (step S16). When the target position is reached, the process ends. On the other hand, if the target position has not been reached, the process returns to step S13, and the processes of steps S13 to S16 are repeated until the target position is reached.

[Modification example]
In the above embodiment, the third lens group front group drive actuator 56 is configured by VCM, but it can also be configured by other actuators.

Further, in the above embodiment, the fourth lens group drive actuator 68 is composed of the VCM, but it can also be composed of other electromagnetic actuators.

Further, in the above embodiment, the zoom operation is manually performed, but it is also possible to use a motor or the like to electrically perform the zoom operation.

Further, in the above-described embodiment, the lens group that is moved by the zoom is driven by the cam mechanism to be moved, but it may be configured to be driven and moved by another drive mechanism.

Further, in the above embodiment, the hall sensor is used for the position detection sensor 84, but a magnetic sensor of the same type as the hall sensor can also be used. That is, a sensor can be used that detects a magnetic field that changes according to the position and outputs a signal proportional to the magnitude of the detected magnetic field.

Further, in the above embodiment, the position of the fourth lens group G4 is detected by using the photo interrupter and the MR sensor, but it can also be detected by the hall sensor. In this case, it is preferable to correct the output of the Hall sensor according to the zoom position as in the case of the front group G3a of the third lens group.

[Second Embodiment]
The output characteristics of the Hall sensor change depending on the mounting condition. Therefore, in order to detect the position of the front group G3a of the third lens group with higher accuracy, it is preferable to consider the mounting state of the sensor. In the present embodiment, the position of the third lens group front group G3a is detected in consideration of the mounting state of the position detection sensor 84.

FIG. 19 is a diagram showing a mounting state of the position detection sensor when properly mounted. FIG. 20 is a diagram showing an attached state of the position detection sensor when it is improperly attached.

As shown in FIG. 19, when properly mounted, the position detection sensor 84 is mounted parallel to the optical axis Z. Further, it is attached to a position at a regular distance D from the position detection magnet 82.

On the other hand, when improperly attached, as shown in FIG. 20, the position detection sensor 84 is attached in an inclined posture with respect to the optical axis Z. Alternatively, it is attached to a position of a distance d different from the regular distance D from the position detection magnet 82.

FIG. 21 is a graph showing the relationship between the position of the front group of the third lens group at a certain zoom position and the output value of the position detection sensor.

In the figure, the solid line W1 is a graph when the position detection sensor 84 is properly attached. Further, the broken line W2 is a graph when the position detection sensor 84 is attached in an improper posture. Further, the alternate long and short dash line W3 is a graph when the position detection sensor 84 is attached to an inappropriate position.

When the position detection sensor 84 is attached in an inappropriate posture (tilted posture), the slope (sensor output sensitivity) of the graph showing the output characteristics of the position detection sensor 84 changes depending on the magnitude of the tilt (broken line W2). See the graph in).

Further, when the position detection sensor 84 is mounted at an inappropriate position, the intercept (sensor output bias) of the graph (see FIG. 15) showing the output characteristics of the position detection sensor 84 changes (see the graph of the alternate long and short dash line W3). ..

When the positional relationship between the position detection sensor 84 and the fourth lens group drive actuator 68 changes due to the zoom operation, the magnetic influence of the position detection sensor 84 on the fourth lens group drive actuator 68 at each zoom position is not uniform. Therefore, the output (position signal) of the position detection sensor 84 cannot be appropriately corrected by the correction function F (x) = αx + β using the above correction coefficients α and β. Therefore, the output (position signal) of the position detection sensor 84 is corrected by the following method.

The inclination θ of the position detection sensor 84 with respect to the optical axis Z is confirmed, and the correction coefficient γ (θ) that changes depending on the inclination θ is added to the correction function F (x) so that F (x) = αx + (β + γ (θ)). ..

Further, the distance d from the position detection magnet 82 is confirmed, and the correction coefficient δ (d) that changes depending on the distance d is added to the correction function F (x), and F (x) = (α + δ (d)) x + (β + γ). (Θ)).

The inclination θ and the distance d are obtained for each individual of the interchangeable lens 1, the correction coefficients γ (θ) and δ (d) are obtained, and the correction information storage unit 146 stores the correction coefficients γ (θ) and δ (d).

The position signal correction unit 142 acquires information on the correction coefficients α and β according to the zoom position and the correction coefficients γ (θ) and δ (d) based on the mounting state from the correction information storage unit 146, and the acquired correction The correction function F (x) = (α + δ (d)) x + (β + γ (θ)) is set based on the coefficients α, β, γ (θ) and δ (d), and the output (position) of the position detection sensor 84 is set. Signal) x is corrected. As a result, the position of the front group G3a of the third lens group can be detected with higher accuracy.

In this embodiment, the position signal is corrected in consideration of both the mounting position (distance d from the position detecting magnet 82) and the mounting posture (tilt θ with respect to the optical axis Z) of the position detection sensor 84. However, the position signal may be corrected by considering at least one of them.

Further, in the present embodiment, the position signal correction unit 142 stores the information of the correction coefficients γ (θ) and δ (d) in the correction information storage unit 146, but the information on the mounting position of the position detection sensor 84 (Distance d from the position detection magnet 82) and mounting posture information (inclination θ with respect to the optical axis Z) may be stored in the correction information storage unit 146. In this case, when the correction function F (x) is set, the correction coefficients γ (θ) and δ (d) are set based on the position information and the posture information.

[Third Embodiment]
The output characteristics of the Hall sensor change depending on the temperature of the usage environment. Therefore, in order to detect the position of the front group G3a of the third lens group with higher accuracy, it is preferable to consider the temperature of the usage environment. In the present embodiment, the position of the front group G3a of the third lens group is detected in consideration of the temperature of the usage environment.

In the position detection sensor 84 composed of a hall sensor, the slope (sensor output sensitivity) and intercept (sensor output bias) of the graph showing the output characteristics change depending on the temperature. Therefore, the output (position signal) of the position detection sensor 84 is corrected by the following method.

F (x) = (α + ε (T)) x + (β + ζ (T)) by adding the slope correction coefficient ε (T) and the intercept correction coefficient ζ (T) that change depending on the temperature T to the correction function F (x). And.

The inclination correction coefficient ε (T) and the intercept correction coefficient ζ (T) are obtained for each individual interchangeable lens 1 and stored in the correction information storage unit 146. The correction coefficients ε (T) and ζ (T) are examples of information necessary for correcting the position signal based on the temperature.

FIG. 22 is a block diagram of a configuration related to the position detection process of the front group of the third lens group when the output of the position detection sensor is corrected based on the temperature.

As shown in the figure, the position signal correction unit 142 acquires the current zoom position information from the zoom position detection unit 120. Further, the position signal correction unit 142 acquires the current temperature information from the temperature detection unit 116. Based on the acquired information, the position signal correction unit 142 has information on the correction coefficients α and β corresponding to the current zoom position, and correction coefficients ε (T) and ζ (T) corresponding to the current temperature T. Information is acquired from the correction information storage unit 146. Then, based on the acquired correction coefficients α, β, ε (T) and ζ (T), the correction function F (x) = (α + ε (T)) x + (β + ζ (T)) is set, and the position detection sensor The output (position signal) x of 84 is corrected. As a result, the position of the front group G3a of the third lens group can be detected with higher accuracy. The temperature information is acquired from the temperature sensor.

Although the mounting state of the position detection sensor 84 is not considered in the present embodiment, the position of the third lens group front group G3a can be detected with higher accuracy by considering the mounting state of the position detection sensor 84. it can. In this case, the correction function F (x) = (α + δ (d) + ε (T)) x + (β + γ (θ) + ζ (T)) is set to correct the output (position signal) x of the position detection sensor 84. ..

[Modification example]
[Modified example of acquisition method of intercept correction coefficient based on temperature]
In the above embodiment, the correction coefficient for each temperature is obtained in advance, but the correction coefficient ζ (T) for the intercept based on the temperature can also be obtained by the following method.

FIG. 23 is a conceptual diagram of a method for obtaining the correction coefficient of the intercept based on the temperature.

As shown in the figure, the front group G3a of the third lens group is moved to the movable end on one side, the output value of the position detection sensor 84 is acquired at that position, and the output value of the acquired position detection sensor 84 is obtained. , Obtain the intercept correction coefficient ζ (T).

In the third lens group front group G3a, the first main guide portion 52 and / or the first sub guide portion 54 abuts on one end, so that the movable end on one side (one end of the movable range) ). In the example shown in FIG. 23, it is located at the end on the image plane side. This position is used as the reference position for calibration.

The output of the position detection sensor 84 when the reference temperature (reference temperature) is set (for example, 25 ° C.) and the front group G3a of the third lens group is positioned at the calibration reference position under the set reference temperature. Find the value for each individual. The obtained output value is stored in the correction information storage unit 146 as a reference output value.

When acquiring the correction coefficient ζ (T) of the intercept based on the temperature, first, the third lens group front group G3a is positioned at the calibration reference position. Next, the output value of the position detection sensor 84 is acquired. Next, the difference between the acquired output value and the reference output value is obtained. The obtained difference is acquired as the intercept correction coefficient ζ (T).

As described above, the correction coefficient ζ (T) of the intercept based on the temperature can be obtained from the output of the position detection sensor 84 when the section is positioned at the calibration reference position. As a result, the correction coefficient ζ (T) of the intercept based on the temperature can be obtained more appropriately.

This process is performed, for example, when the interchangeable lens 1 is activated (synonymous with the activation of the camera).

[Conditions for temperature-based correction processing]
The temperature-based correction may be performed only when the temperature detected by the temperature sensor exceeds a predetermined allowable range. For example, an allowable range is set in a certain range before and after the reference temperature, and when the allowable range is exceeded, correction based on the above temperature is performed. As a result, the startup time of the interchangeable lens 1 can be shortened. In particular, when the intercept correction coefficient ζ (T) is obtained by the method shown in the above modification, the process of moving the lens to the calibration reference position can be omitted, so that the start-up time can be significantly shortened.

[Fourth Embodiment]
In the interchangeable lens 1 of the above embodiment, the actuator (fourth lens group drive actuator 68) for driving the fourth lens group G4 is composed of a moving coil type VCM. In this case, the influence of the magnetism on the position detection sensor 84 from the fourth lens group drive actuator 68 need only consider the fluctuation of the positional relationship between the two due to the zoom.

However, when the actuator that drives the fourth lens group G4 is composed of a moving magnet type VCM, high-precision detection cannot be performed even if only the change in the positional relationship due to the zoom is taken into consideration. This is because the moving magnet type VCM moves the magnet together with the moving part. Therefore, in order to detect the position of the third lens group front group G3a with higher accuracy, the position detection sensor 84 takes into consideration the position of the movable portion driven by the actuator, that is, the position of the fourth lens group G4. It is necessary to correct the output (position signal) of.

[Interchangeable lens configuration]
First, a configuration of an interchangeable lens when the actuator for driving the fourth lens group G4 (fourth lens group drive actuator) is composed of a moving magnet type VCM will be described. Here, only the configuration of the drive unit of the fourth lens group G4 will be described.

FIG. 24 is a cross-sectional view showing a schematic configuration of an interchangeable lens when the fourth lens group drive actuator is composed of a moving magnet type VCM.

As shown in the figure, in the interchangeable lens 1 of the present embodiment, the fourth lens group drive actuator 66 is composed of a moving magnet type VCM. The fourth lens group movable holding frame 26B is provided with a plurality of driving magnets 66A and a plurality of inner yokes 66B configured by the moving magnet type VCM. Further, the fourth lens group base holding frame 26A is provided with a driving coil 66C constituting a moving magnet type VCM and a plurality of outer yokes 66D.

The drive coil 66C is wound so as to surround the outer peripheral portion of the fourth lens group movable holding frame 26B, and is attached to the inner peripheral portion of the fourth lens group base holding frame 26A. The fourth lens group movable holding frame 26B moves inside the driving coil 66C along the optical axis Z.

Similar to the third lens group front group drive actuator 56, the plurality of drive magnets 66A are grouped into two groups and symmetrical with respect to the straight line L passing through the optical axis Z in the cross section orthogonal to the optical axis Z. Arranged (see FIGS. 6 and 10). The plurality of inner yokes 66B are arranged so as to correspond to the driving magnets 66A. Each inner yoke 66B is integrated with the corresponding drive magnet 66A and attached to the fourth lens group movable holding frame 26B. The plurality of outer yokes 66D are arranged corresponding to the plurality of inner yokes 66B. Each outer yoke 66D is arranged so as to face the corresponding inner yoke 66B with the drive coil 66C interposed therebetween.

According to the interchangeable lens 1 having the above configuration, when the fourth lens group drive actuator 66 is driven, the fourth lens group G4 moves along the optical axis Z. At this time, the driving magnet 66A also moves together with the fourth lens group G4.

[Correction of position detection sensor output]
[Structure related to position detection processing of the front group of the third lens group including correction of the output of the position detection sensor]
FIG. 25 is a block diagram of a configuration related to the position detection process of the front group of the third lens group including the correction of the output of the position detection sensor.

Similar to the interchangeable lens 1 of the above embodiment, the lens control unit 100 performs the position detection process of the third lens group front group G3a including the correction of the output of the position detection sensor 84. However, the lens control unit 100 of the present embodiment is different from the lens control unit 100 of the above embodiment in that the function of the relative position calculation unit 148 is further realized.

The relative position calculation unit 148 calculates the relative position of the position detection sensor 84 with respect to the fourth lens group G4 (synonymous with the distance between the fourth lens group G4 and the position detection sensor 84). The relative position calculation unit 148 calculates the relative position of the position detection sensor 84 with respect to the fourth lens group G4 based on the zoom position and the position of the fourth lens group G4.

The drive magnet 66A of the fourth lens group drive actuator 66 moves together with the fourth lens group G4. Therefore, calculating the relative position of the position detection sensor 84 with respect to the fourth lens group G4 is synonymous with calculating the relative position of the position detection sensor 84 with respect to the driving magnet 66A.

The relative position calculation unit 148 acquires the zoom position information from the zoom position detection unit 120, and acquires the position information of the fourth lens group G4 from the fourth lens group position detection unit 90.

The position signal correction unit 142 corrects the position signal acquired by the position signal acquisition unit 140 based on the relative position information calculated by the relative position calculation unit 148. Specifically, the relative position information is acquired from the relative position calculation unit 148, and the correction coefficient information corresponding to the acquired relative position is acquired from the correction information storage unit 146. Then, the position signal is corrected based on the acquired correction coefficient. That is, the correction function F (x) is set based on the acquired correction coefficient, and the position signal x is corrected according to the set correction function F (X).

The correction coefficient is obtained in advance for each relative position, and is associated with the relative position information and stored in the correction information storage unit 146.

The position calculation unit 144 calculates the position of the third lens group front group G3a based on the corrected position signal X. As a result, the correct position can be detected regardless of the zoom position.

[Procedure for detecting the position of the front group of the third lens group including the correction of the output of the position detection sensor]
FIG. 26 is a flowchart showing a procedure (position detection method) of the position detection process of the front group of the third lens group including the correction of the output of the position detection sensor.

First, the position signal x output from the position detection sensor 84 is acquired (step S21). Next, information on the current zoom position is acquired from the zoom position detection unit 120 (step S22). Next, the position information of the fourth lens group G4 is acquired from the fourth lens group position detection unit 90 (step S23). Next, the relative position of the position detection sensor 84 with respect to the fourth lens group G4 is calculated based on the acquired zoom position information and the position information of the fourth lens group G4 (step S24). Next, the correction coefficient corresponding to the calculated relative position is acquired (step S25). Next, the correction function F (x) is set based on the acquired correction coefficient, and the position signal x is corrected (step S26). Next, the third lens group front group G3a is calculated based on the corrected position signal X (step S27). As a result, the position of the front group G3a of the third lens group can be obtained.

In this way, when the actuator that drives the fourth lens group G4 is composed of a moving magnet type VCM, the output (position signal) of the position detection sensor 84 is corrected in consideration of the position of the fourth lens group G4. By doing so, the position of the front group G3a of the third lens group can always be detected accurately.

Also in this embodiment, a correction in consideration of the mounting state and temperature of the position detection sensor 84 can be applied, which enables more accurate position detection.

[Fifth Embodiment]
In the above embodiment, the case where the present invention is applied to a lens barrel in which both the first optical element and the second optical element move in a direction parallel to the optical axis has been described as an example, but the application of the present invention is the same. It is not limited to. A lens barrel in which both the first optical element and the second optical element move in a direction perpendicular to the optical axis, and one of the first optical element and the second optical element moves in a direction parallel to the optical axis, and the other The present invention can also be applied to a lens barrel that moves in a direction perpendicular to the optical axis.

In the following, a case where the present invention is applied to a lens barrel provided with a lens that moves in a direction perpendicular to the optical axis and a lens that moves in a direction parallel to the optical axis will be described as an example.

[Structure of a lens barrel provided with a lens that moves in a direction perpendicular to the optical axis and a lens that moves in a direction parallel to the optical axis]
FIG. 27 is a cross-sectional view showing an example of a lens barrel including a lens that moves in a direction perpendicular to the optical axis and a lens that moves in a direction parallel to the optical axis. FIG. 28 is a cross-sectional view taken along the line 28-28 of FIG. 27. FIG. 29 is a cross-sectional view taken along the line 29-29 of FIG. 27.

The lens barrel 200 of the present embodiment includes a first lens unit 220 including a lens moving in a direction perpendicular to the optical axis Z, and a second lens including a lens moving in a direction parallel to the optical axis Z. It includes a unit 240. The distance between the first lens unit 220 and the second lens unit 240 is variable depending on, for example, a zoom. In the present embodiment, the first lens unit 220 and the second lens unit 240 are moved by the cam mechanism, and the intervals thereof are variable.

Further, in the above-described embodiment, the case where the present invention is applied to an interchangeable lens has been described as an example, but the present invention can also be applied to a lens integrally assembled with a camera.

[Lens barrel body]
The lens barrel main body 210 has a fixed cylinder 212 and a cam cylinder 214. The cam cylinder 214 is fitted to the inner peripheral portion of the fixed cylinder 212, and the inner peripheral portion of the fixed cylinder 212 is rotatably held in the circumferential direction.

[1st lens unit]
The first lens unit 220 is a so-called camera shake correction lens unit. As shown in FIGS. 27 and 28, the first lens unit 220 includes a first lens 222, which is a lens for camera shake correction, a first lens holding frame 224 for holding the first lens 222, and a first lens 222. The position of the first lens X-axis direction drive actuator 226X that drives in the X-axis direction, the first lens Y-axis direction drive actuator 226Y that drives the first lens 222 in the Y-axis direction, and the position of the first lens 222 in the X-axis direction. It includes a first lens X-axis direction position detection sensor 228X for detecting, and a first lens Y-axis direction position detection sensor 228Y for detecting the position of the first lens 222 in the Y-axis direction. The first lens unit 220 is an example of the first unit.

[First lens]
As described above, the first lens 222 is a lens for camera shake correction, and corrects camera shake by moving in a plane orthogonal to the optical axis Z. The first lens 222 is an example of the first optical element.

[First lens holding frame]
The first lens holding frame 224 is composed of a first lens base holding frame 224A and a first lens movable holding frame 224B. A plurality of rigid spheres 225a are sandwiched between the first lens base holding frame 224A and the first lens movable holding frame 224B, and a plurality of locations are connected by a spring 225b to be integrated. As a result, the first lens movable holding frame 224B is movably supported with respect to the first lens base holding frame 224A in a plane orthogonal to the optical axis Z.

The first lens base holding frame 224A is provided with three first lens zoom driving cam followers 232 on the outer peripheral portion thereof. The three first lens zoom drive cam followers 232 are arranged at equal intervals in the circumferential direction. Each first lens zoom drive cam follower 232 is fitted into the first lens zoom drive cam groove 214A provided in the cam cylinder 214 and the first lens zoom drive straight groove 212A provided in the fixed cylinder 212, respectively. .. As a result, the first lens base holding frame 224A is held in the fixed cylinder 212. Further, when the cam cylinder 214 is rotated, the first lens base holding frame 224A moves in the fixed cylinder 212 along the optical axis Z in a predetermined movement locus.

[1st lens X-axis direction drive actuator and 1st lens Y-axis direction drive actuator]
The first lens X-axis direction drive actuator 226X drives the first lens 222 in the X-axis direction. The first lens Y-axis direction drive actuator 226Y drives the first lens 222 in the Y-axis direction. As shown in FIG. 28, the X-axis and the Y-axis are set as two axes orthogonal to each other in a plane orthogonal to the optical axis Z. The first lens X-axis direction drive actuator 226X and the first lens Y-axis direction drive actuator 226Y are both composed of a moving coil type VCM. Therefore, the first lens movable holding frame 224B, which is a movable portion, is provided with a driving coil. The first lens X-axis direction drive actuator 226X and the first lens Y-axis direction drive actuator 226Y are examples of the first actuator.

[1st lens X-axis direction position detection sensor and 1st lens Y-axis direction position detection sensor]
The first lens X-axis direction position detection sensor 228X detects the position of the first lens 222 in the X-axis direction with respect to a preset reference position. The first lens Y-axis direction position detection sensor 228Y detects the position of the first lens 222 in the Y-axis direction with respect to a preset reference position. The first lens X-axis direction position detection sensor 228X and the first lens Y-axis direction position detection sensor 228Y are both composed of a hall sensor, and are of a position detection magnet provided in the first lens movable holding frame 224B which is a movable portion. The position is detected, and the positions of the first lens 222 in the X-axis direction and the Y-axis direction are detected. Specifically, the first lens X-axis direction position detection sensor 228X detects the position of the X-axis direction position detection magnet 230X provided in the first lens movable holding frame 224B, and detects the position of the X-axis direction position detection magnet 230X, and the X-axis of the first lens 222. Detect the position of the direction. Further, the first lens Y-axis direction position detection sensor 228Y detects the position of the Y-axis direction position detection magnet 230Y provided on the first lens movable holding frame 224B, and detects the position of the first lens 222 in the Y-axis direction. Is detected.

[Second lens unit]
The second lens unit 240 is a so-called focus adjustment lens unit. As shown in FIGS. 27 and 29, the second lens unit 240 is parallel to the second lens 242, which is a lens for adjusting the focus, the second lens holding frame 244 that holds the second lens 242, and the optical axis Z. It includes a pair of second lens drive actuators 246 that drive in various directions, and a second lens position detection unit 248 that detects the position of the second lens 242. The second lens unit 240 is an example of the second unit.

[Second lens]
As described above, the second lens 242 is a lens for adjusting the focus (so-called focus lens), and the focus is adjusted by moving along the optical axis Z. The second lens 242 is an example of the second optical element.

[Second lens holding frame]
The second lens holding frame 244 is composed of a second lens base holding frame 244A and a second lens movable holding frame 244B. The second lens movable holding frame 244B is arranged in the second lens base holding frame 244A and is movably supported in the second lens base holding frame 244A in a direction parallel to the optical axis Z. The second lens 242 is held by the second lens movable holding frame 244B.

The second lens base holding frame 244A is provided with three second lens zoom driving cam followers 250 on the outer peripheral portion thereof. The three second lens zoom drive cam followers 250 are arranged at equal intervals in the circumferential direction. Each second lens zoom drive cam follower 250 is fitted into a second lens zoom drive cam groove 214B provided in the cam cylinder 214 and a second lens zoom drive straight groove 212B provided in the fixed cylinder 212, respectively. .. As a result, the second lens base holding frame 244A is held in the fixed cylinder 212. Further, when the cam cylinder 214 is rotated, the second lens base holding frame 244A moves in the fixed cylinder 212 along the optical axis Z in a predetermined movement locus.

Inside the second lens base holding frame 244A, a main shaft 252 and a sub shaft 254 for guiding the second lens movable holding frame 244B are provided. The main shaft 252 and the sub shaft 254 are arranged in parallel with the optical axis Z, respectively. The second lens movable holding frame 244B includes a main guide portion 256 that slides along the main shaft 252 and a sub guide portion 258 that slides along the sub shaft 254. The second lens movable holding frame 244B is slidably supported by the main shaft 252 and the sub shaft 254 via the main guide portion 256 and the sub guide portion 258.

[Second lens drive actuator]
The second lens drive actuator 246 drives the second lens 242. The second lens drive actuator 246 is composed of a moving coil type VCM which is an electromagnetic actuator. Therefore, the second lens movable holding frame 244B, which is a movable portion, is provided with a driving coil. The second lens drive actuator 246 is an example of the second actuator.

[Second lens position detector]
The second lens position detection unit 248 detects the position of the second lens 242. The second lens position detection unit 248 detects the position of the second lens movable holding frame 244B in the second lens base holding frame 244A, and detects the position of the second lens 242. More specifically, the position of the second lens movable holding frame 244B with respect to the origin set in the second lens base holding frame 244A is detected, and the position of the second lens 242 with respect to the origin is detected. The second lens position detection unit 248 is an example of the second optical element position detection unit.

The second lens position detection unit 248 includes an origin detection unit 248A that detects that the second lens 242 is located at the origin, and a displacement amount detection unit 248B that detects the displacement amount of the second lens 242. The second lens position detection unit 248 detects that the second lens 242 is located at the origin by the origin detection unit 248A, detects the displacement amount from the origin by the displacement amount detection unit 248B, and positions the second lens 242. Is detected. The origin detection unit 248A is composed of a light-shielding plate and a photo interrupter. The displacement amount detection unit 248B includes a magnetic scale and an MR sensor.

[Operation of lens barrel]
In the lens barrel 200 of the present embodiment configured as described above, by rotating the cam cylinder 14, the first lens unit 220 and the second lens unit 240 move along the optical axis Z in a predetermined movement locus. To move. Further, by driving the first lens X-axis direction drive actuator 226X and the first lens Y-axis direction drive actuator 212Y, the first lens 222 moves in a plane orthogonal to the optical axis Z. Further, by driving the second lens drive actuator 246, the second lens 242 moves in parallel with the optical axis Z.

The position of the first lens 222 in the first lens unit 220 is detected by the first lens X-axis direction position detection sensor 228X and the first lens Y-axis direction position detection sensor 228Y. Further, the position of the second lens 242 in the second lens unit 240 is detected by the second lens position detection unit 248.

[Correction of output of 1st lens X-axis direction position detection sensor and 1st lens Y-axis direction position detection sensor]
The first lens X-axis direction position detection sensor 228X and the first lens Y-axis direction position detection sensor 228Y composed of Hall sensors correspond to the relative positional relationship between the first lens unit 220 and the second lens unit 240. The output is corrected. The output (position signal) is corrected by the following procedure.

First, the position signal output from the first lens X-axis direction position detection sensor 228X and the position signal output from the first lens Y-axis direction position detection sensor 228Y are acquired.

Next, information on the relative positional relationship between the first lens unit 220 and the second lens unit 240 is acquired. Since the first lens unit 220 and the second lens unit 240 move according to a known movement locus, their positional relationship is known. The relative position of the first lens unit 220 with respect to the second lens unit 240 is uniquely determined from the rotational position of the cam cylinder 214, the position of the first lens unit 220 on the optical axis, or the position of the second lens unit 240. It is decided. Therefore, these pieces of information are acquired to obtain information on the relative positional relationship between the first lens unit 220 and the second lens unit 240.

Next, the correction coefficient information is acquired based on the acquired information on the relative positional relationship between the first lens unit 220 and the second lens unit 240. The correction coefficient information is obtained in advance for each position of the first lens unit 220 relative to the second lens unit 240 and stored in the storage unit. In addition, the correction coefficient information is prepared individually for each sensor. That is, a correction coefficient for the output from the first lens X-axis direction position detection sensor 228X and a correction coefficient for the output from the first lens Y-axis direction position detection sensor 228Y are individually prepared.

Next, the correction function is set based on the acquired correction coefficient, and the position signal is corrected. More specifically, the correction function in the X-axis direction is set based on the acquired correction coefficient in the X-axis direction, and the position signal in the X-axis direction output from the first lens X-axis direction position detection sensor 228X is corrected. To do. Further, a correction function in the Y-axis direction is set based on the acquired correction coefficient in the Y-axis direction, and the position signal in the Y-axis direction output from the first lens Y-axis direction position detection sensor 228Y is corrected.

Next, the position of the first lens 222 in the X-axis direction and the position in the Y-axis direction are calculated based on the corrected position signals in the X-axis direction and the Y-axis direction.

In this way, the outputs of the first lens X-axis direction position detection sensor 228X and the first lens Y-axis direction position detection sensor 228Y are corrected according to the relative positional relationship between the first lens unit 220 and the second lens unit 240. By doing so, the position of the first lens 222 can always be detected accurately.

In the present embodiment, the second lens 242 is configured to move in parallel with the optical axis Z, but the present invention is also applied when the second lens 242 moves in the direction perpendicular to the optical axis Z. it can. The present invention can also be applied when the first lens 222 moves in parallel with the optical axis Z and the second lens 242 moves in the direction perpendicular to the optical axis Z.

Further, in the above series of embodiments, the case where the present invention is applied to an interchangeable lens has been described as an example, but the application of the present invention is not limited to this, and the application is not limited to this, and is applied to a lens barrel integrally provided with a camera. Can be applied in the same way.

Further, the lens barrel to which the present invention can be applied is not limited to the lens barrel of a camera, but can be applied to the lens barrel of various optical devices such as a projector, a microscope, and binoculars.

Further, in the above embodiment, the case where the relative positional relationship between the first unit and the second unit changes depending on the zoom has been described as an example, but the relative positional relationship between the first unit and the second unit under other conditions. It can be applied in the same way when is changed.

[Sixth Embodiment]
[Device configuration]
FIG. 30 is a schematic configuration diagram of an imaging device to which the present invention is applied.

The image pickup device 300 shown in the figure is a digital camera having a so-called sensor shift type image stabilization function, and is an image pickup lens 310, an image sensor 350 that captures an optical image of a subject through the image pickup lens 310, and an image sensor. A camera shake correction mechanism 360 for correcting camera shake by moving the 350 in parallel in a plane orthogonal to the optical axis Z is provided.

[Imaging lens]
The image pickup lens 310 is composed of a zoom lens having a zoom function and a focus adjustment function. The imaging lens 310 is configured by combining a plurality of lenses, and the focal length is continuously changed by moving some of the lenses along the optical axis Z. Further, the focus is adjusted by moving a part of the lenses (focus lenses) along the optical axis Z. In FIG. 30, only the focus lens 312 is shown for convenience of explanation.

In the image pickup apparatus 300 of the present embodiment, the focus lens 312 moves in a predetermined movement locus by zooming, and is driven by an actuator to move independently. The focus lens 312 is an example of a movable lens. The image pickup lens 310 includes a focus lens driving unit 314 for driving the focus lens 312 and a focus lens position detecting unit 316 for detecting the position of the focus lens 312.

[Focus lens holding structure]
FIG. 31 is a cross-sectional view taken along the line 31-31 of FIG.

The focus lens 312 is held by the focus lens holding frame 318 and arranged in the image pickup lens 310. The focus lens holding frame 318 is composed of a focus lens base holding frame 318A and a focus lens movable holding frame 318B. The focus lens movable holding frame 318B is arranged in the focus lens base holding frame 318A and is movably supported in the focus lens base holding frame 318A in a direction parallel to the optical axis Z. The focus lens 312 is held by the focus lens movable holding frame 318B.

The focus lens base holding frame 318A is provided with three focus lens zoom drive cam followers 320 on the outer peripheral portion thereof. The three focus lens zoom drive cam followers 320 are arranged at equal intervals in the circumferential direction. Each focus lens zoom drive cam follower 320 is fitted into the focus lens zoom drive cam groove 322A provided in the cam cylinder 322 and the focus lens zoom drive straight groove 324A provided in the fixed cylinder 324, respectively. As a result, when the cam cylinder 322 is rotated, the focus lens base holding frame 318A moves along the optical axis Z in a predetermined movement locus. The cam cylinder 322 is connected to a zoom ring (not shown) provided on the outer circumference of the image pickup lens 310, and rotates in conjunction with the zoom ring. Further, the set zoom position is detected by a zoom position detection unit (not shown).

A main shaft 326 and a sub shaft 328 are provided in the focus lens base holding frame 318A. The main shaft 326 and the sub-axis 328 are arranged along the optical axis Z, respectively.

The focus lens movable holding frame 318B includes a main guide portion 330 that slides along the main shaft 326 and a sub guide portion 332 that slides along the sub shaft 328. The focus lens movable holding frame 318B is slidably supported by the main shaft 326 and the sub shaft 328 via the main guide portion 330 and the sub guide portion 332.

[Focus lens drive unit]
The focus lens drive unit 314 is composed of a pair of focus lens drive actuators 334. The focus lens drive actuator 334 is composed of a moving coil type VCM. Therefore, the focus lens movable holding frame 318B, which is a movable portion, is provided with a driving coil. The focus lens drive actuator 334 is an example of the first actuator.

[Focus lens position detector]
The focus lens position detection unit 316 is composed of a focus lens position detection magnet 316A and a focus lens position detection sensor 316B.

The focus lens position detection magnet 316A is provided on the focus lens movable holding frame 318B, which is a movable portion.

The focus lens position detection sensor 316B is provided on the focus lens base holding frame 318A. The focus lens position detection sensor 316B detects the position of the focus lens position detection magnet 316A and detects the position of the focus lens 312. The position here is a position within the focus lens base holding frame 318A. That is, it is a position with respect to a reference position set in the focus lens base holding frame 318A.

The focus lens 312, the focus lens drive unit 314, and the focus lens position detection unit 316 form one unit with reference to the focus lens holding frame 318, and this unit moves in parallel with the optical axis Z by a zoom operation. The unit based on the focus lens holding frame 318 is an example of a movable unit. Further, the cam mechanism including the cam cylinder 322, the fixed cylinder 324, and the focus lens zoom drive cam follower 320 is an example of the movable unit drive unit.

[Image sensor]
The image sensor 350 captures an optical image of the subject via the image pickup lens 310. The image sensor 350 is composed of a known area image sensor such as a CMOS type (CMOS: Complementary Metal-Oxide Semiconductor) or a CCD type (CCD: Charge Coupled Device).

[Image Stabilizer]
FIG. 32 is a cross-sectional view taken along the line 32-32 of FIG.

The camera shake correction mechanism 360 corrects camera shake by translating the image sensor 350 in a plane orthogonal to the optical axis Z. The image stabilization mechanism 360 detects the positions of the image sensor holding frame 362 that movably supports the image sensor 350 in a plane orthogonal to the optical axis Z, the image sensor driving unit that drives the image sensor 350, and the image sensor 350. An image sensor position detection unit is provided.

[Image sensor holding frame]
The image sensor holding frame 362 includes an image sensor movable holding frame 362A that holds the image sensor 350, and an image sensor base holding frame 362B that slidably supports the image sensor movable holding frame 362A in a plane orthogonal to the optical axis Z. Consists of. A plurality of rigid spheres 368 are sandwiched between the image sensor movable holding frame 362A and the image sensor base holding frame 362B, and a plurality of locations are connected by a spring 370 to be integrated. As a result, the image sensor movable holding frame 362A is movably supported with respect to the image sensor base holding frame 362B in a plane orthogonal to the optical axis Z.

[Image sensor drive unit]
The image sensor drive unit includes an image sensor X-axis direction drive actuator 364X that drives the image sensor movable holding frame 362A in the X-axis direction, and an image sensor Y-axis direction drive actuator 364Y that drives the image sensor movable holding frame 362A in the Y-axis direction. And. As shown in FIG. 32, the X-axis and the Y-axis are set as two axes orthogonal to each other in a plane orthogonal to the optical axis Z. The image sensor X-axis direction drive actuator 364X and the image sensor Y-axis direction drive actuator 364Y are both composed of a moving coil type VCM which is an electromagnetic actuator. Therefore, the image sensor movable holding frame 362A, which is a movable portion, is provided with a driving coil. The image sensor X-axis direction drive actuator 364X and the image sensor Y-axis direction drive actuator 364Y are examples of the second actuator.

By driving the image sensor movable holding frame 362A in the X-axis direction by the image sensor X-axis direction drive actuator 364X, the image sensor 350 moves in the X-axis direction in the plane orthogonal to the optical axis Z. Further, by driving the image sensor movable holding frame 362A in the Y-axis direction by the image sensor Y-axis direction drive actuator 364Y, the image sensor 350 moves in the Y-axis direction in the plane orthogonal to the optical axis Z.

[Image sensor position detector]
The image sensor position detection unit includes an image sensor X-axis position detection sensor 366X that detects the position of the image sensor 350 in the X-axis direction, and an image sensor Y-axis direction position detection sensor that detects the position of the image sensor 350 in the Y-axis direction. 366Y and. Both the image sensor X-axis direction position detection sensor 366X and the image sensor Y-axis direction position detection sensor 366Y are composed of hall sensors and detect the position of the position detection magnet provided in the image sensor movable holding frame 362A which is a movable part. Then, the positions of the image sensor 350 in the X-axis direction and the Y-axis direction are detected. Specifically, the image sensor X-axis direction position detection sensor 366X detects the position of the X-axis direction position detection magnet 368X provided in the image sensor movable holding frame 362A, and detects the position of the image sensor 350 in the X-axis direction. Is detected. Further, the image sensor Y-axis direction position detection sensor 366Y detects the position of the Y-axis direction position detection magnet 368Y provided in the image sensor movable holding frame 362A, and detects the position of the image sensor 350 in the Y-axis direction. ..

[Correction of output of focus lens position detection sensor]
In the image pickup apparatus 300 configured as described above, the focus lens holding frame 318 moves along the optical axis Z by the zoom operation. As a result, the distance between the focus lens holding frame 318 and the image sensor 350 changes. When the distance between the focus lens holding frame 318 and the image sensor 350 changes, the distance between the image sensor driving unit and the focus lens position detection sensor 316B changes. Since the image sensor drive unit contains a magnetic material, the output characteristics of the focus lens position detection sensor 316B change when the distance between the image sensor drive unit and the focus lens position detection sensor 316B changes. Therefore, the output (position signal) of the focus lens position detection sensor 316B is corrected according to the zoom position. This process is performed by the control unit of the image pickup apparatus 300. The control unit of the image pickup apparatus 300 is composed of a computer including a CPU, a ROM, and a RAM, and provides a correction function for the output of the focus lens position detection sensor by executing a predetermined program.

FIG. 33 is a block diagram of the output correction function of the focus lens position detection sensor provided by the control unit of the image pickup apparatus.

The control unit of the image pickup apparatus 300 calculates the position of the focus lens 312 based on the position signal acquisition unit 380 that acquires the position signal, the position signal correction unit 382 that corrects the acquired position signal, and the corrected position signal. The function of the position calculation unit 384 is provided.

The position signal acquisition unit 380 acquires a signal output from the focus lens position detection sensor 316B as a position signal.

The position signal correction unit 382 corrects the position signal acquired by the position signal acquisition unit 380 based on the zoom position. The position signal correction unit 382 acquires zoom position information from the zoom position detection unit 388, and acquires correction coefficient information corresponding to the acquired zoom position from the correction information storage unit 386. Then, a correction function is set based on the acquired correction coefficient, and the position signal is corrected.

The correction coefficient can be obtained by the same method as in the first embodiment. That is, since the relative positional relationship between the focus lens position detection sensor 316B and the image sensor 350 at each zoom position is uniquely determined and known, it is corrected in advance from the output of the focus lens position detection sensor 316B for each zoom position. Find the coefficients α and β. The obtained correction coefficient information is stored in the correction information storage unit 386 in association with the zoom position information. The correction information storage unit 386 is composed of, for example, a ROM.

The position calculation unit 384 calculates the position of the focus lens 312 based on the corrected position signal. As a result, the correct position can be detected regardless of the zoom position.

[Procedure of focus lens position detection process including correction of focus lens position detection sensor output]
FIG. 34 is a flowchart showing a procedure (position detection method) of the focus lens position detection process including correction of the output of the focus lens position detection sensor.

First, the position signal output from the focus lens position detection sensor 316B is acquired (step S31). Next, information on the current zoom position is acquired from the zoom position detection unit 120 (step S32). Next, the correction coefficient corresponding to the zoom position is acquired (step S33). Next, a correction function is set based on the acquired correction coefficient, and the position signal is corrected (step S34). Next, the position of the focus lens 312 is calculated based on the corrected position signal (step S35). As a result, the exact position of the focus lens 312 can be obtained.

By correcting the output of the position detection sensor 84 according to the zoom position in this way, the position of the front group G3a of the third lens group can always be accurately detected.

[Correction of output of image sensor X-axis direction position detection sensor and image sensor Y-axis direction position detection sensor]
As for the image sensor X-axis direction position detection sensor 366X and the image sensor Y-axis direction position detection sensor 366Y, the influence of magnetism received from the focus lens drive actuator 334 changes depending on the zoom operation. Therefore, it is preferable to correct the output (position signal) of the image sensor X-axis direction position detection sensor 366X and the image sensor Y-axis direction position detection sensor 366Y by the same method. As a result, the position of the image sensor 350 can be accurately detected.

[Modification example]
Also in this embodiment, a correction in consideration of the mounting state and temperature of the position detection sensor can be applied, which enables more accurate position detection.

Further, in the above embodiment, the case where the movable lens moves in the direction parallel to the optical axis has been described as an example, but the present invention can also be applied to the case where the movable lens moves in the direction perpendicular to the optical axis.

Further, the application of the present invention is not limited to an image pickup device as a single unit, but can be similarly applied to an image pickup device assembled in a mobile phone, a smartphone, a tablet computer, or the like. Further, the imaging device to which the present invention is applied is not limited to an imaging device that captures a still image, but can also be applied to an imaging device that captures a moving image.

[Other embodiments]
The hardware configuration for realizing the function of correcting the output of the position detection sensor can be configured by various processors. For various processors, the circuit configuration can be changed after manufacturing the CPU, FPGA (FPGA: Field Programmable Gate Array), which is a general-purpose processor that functions as a processing unit that executes software (programs) to perform various processes. Includes a dedicated electric circuit, which is a processor with a circuit configuration specially designed to execute specific processing such as PLD (Programmable Logic Device), ASIC (Application Specific Integrated Circuit), etc. Is done.

One processing unit may be composed of one of these various processors, or may be composed of two or more processors of the same type or different types. For example, it may be composed of a plurality of FPGAs, or may be composed of a combination of a CPU and an FPGA.

Further, a plurality of processing units may be configured by one processor. As an example of configuring a plurality of processing units with one processor, first, as represented by computers such as clients and servers, one processor is configured by combining one or more CPUs and software. There is a form in which this processor functions as a plurality of processing units. Second, a processor that realizes the functions of the entire system including multiple processing units with one IC chip (IC: Integrated Circuit) is used, as typified by System On Chip (SoC). There is a form. As described above, the various processing units are configured by using one or more of the above-mentioned various processors as a hardware-like structure.

Further, the hardware structure of these various processors is, more specifically, an electric circuit in which circuit elements such as semiconductor elements are combined.

A program for realizing a function of correcting the output of the position detection sensor described in the above embodiment on a computer is recorded on an optical disk, a magnetic disk, a semiconductor memory, or a computer-readable medium which is a non-temporary information storage medium such as a tangible object. However, it is possible to provide a program through this information storage medium. Further, instead of the mode in which the program is stored and provided in such a tangible non-temporary information storage medium, it is also possible to provide the program signal as a download service by using a telecommunication line such as the Internet.

1 Interchangeable lens 2 Exterior 3 Focus ring 4 Zoom ring 5 Aperture ring 10 Lens barrel body 12 Fixed cylinder 12A 1st lens group Zoom drive straight groove 12B 2nd lens group Zoom drive straight groove 12C 3rd lens group Zoom drive Straight groove 12D 4th lens group Zoom drive straight groove 14 Cam cylinder 14A 1st lens group Zoom drive cam groove 14B 2nd lens group Zoom drive cam groove 14C 3rd lens group Zoom drive cam groove 14D 4th lens group Zoom drive cam groove 16 Mount 16A Terminal 20 1st lens group holding frame 22 2nd lens group holding frame 24 3rd lens group holding frame 24A 3rd lens group base holding frame 24B 3rd lens group movable holding frame 26 4th lens Group holding frame 26A 4th lens group base holding frame 26B 4th lens group movable holding frame 28 5th lens group holding frame 30 Aperture unit 32 1st lens group zoom drive cam follower 34 2nd lens group zoom drive cam follower 36 3rd Lens group zoom drive cam follower 38 4th lens group zoom drive cam follower 48 1st main shaft 50 1st sub shaft 52 1st main guide part 52A Sliding part 54 1st sub guide part 54A Groove part 56 3rd lens group front group drive Actuator 56A Drive magnet 56B Inner yoke 56C Drive coil 56D Outer yoke 58 2nd main shaft 60 2nd sub-axis 62 2nd main guide part 62A Sliding part 64 2nd sub-guide part 64A Groove part 66 4th lens group drive actuator 66A Drive magnet 66B Inner yoke 66C Drive coil 66D Outer yoke 68 4th lens group Drive actuator 68A Drive coil 68B Drive magnet 68C Inner yoke 68D Outer yoke 70 Coil holder 80 3rd lens group Front group position detection unit 82 position Detection magnet 84 Position detection sensor 90 Fourth lens group position detection unit 92 Origin detection unit 92A Shading plate 92B Photo interrupter 94 Displacement amount detection unit 94A Magnetic scale 94B MR sensor 100 Lens control unit 110 Third lens group front group drive unit 112 4th lens group drive unit 114 aperture drive unit 116 temperature detection unit 118 focus operation detection unit 120 zoom position detection unit 122 aperture setting detection unit 130 camera control unit 140 position signal acquisition unit 142 position signal correction unit 144 position calculation unit 146 correction information Storage unit 148 Relative position calculation unit 200 lens Lens barrel 210 Lens barrel body 212 Fixed cylinder 212A 1st lens zoom drive straight groove 212B 2nd lens zoom drive straight groove 212Y 1st lens Y axis direction drive actuator 214 Cam cylinder 214A 1st lens zoom drive cam groove 214B 2nd lens zoom drive cam groove 220 1st lens unit 222 1st lens 224 1st lens holding frame 224A 1st lens base holding frame 224B 1st lens movable holding frame 225a Rigid sphere 225b Spring 226X 1st lens X Axial drive Actuator 226Y 1st lens Y-axis direction drive actuator 228X 1st lens X-axis direction position detection sensor 228Y 1st lens Y-axis direction position detection sensor 230X X-axis direction position detection magnet 230Y Y-axis direction position detection magnet 232 1st lens Zoom drive cam follower 240 2nd lens unit 242 2nd lens 244 2nd lens holding frame 244A 2nd lens base holding frame 244B 2nd lens movable holding frame 246 2nd lens drive actuator 248 2nd lens position detection unit 248A Origin detection unit 248B Displacement amount detection unit 250 Second lens zoom drive cam follower 252 Main shaft 254 Sub-axis 256 Main guide unit 258 Sub-guide unit 300 Imaging device 310 Imaging lens 312 Focus lens 314 Focus lens drive unit 316 Focus lens position detection unit 316A Focus lens position Detection magnet 316B Focus lens position detection sensor 318 Focus lens holding frame 318A Focus lens base holding frame 318B Focus lens movable holding frame 320 Focus lens Zoom drive cam follower 322 Cam cylinder 322A Focus lens Zoom drive cam groove 324 Fixed cylinder 324A Focus lens Straight groove for zoom drive 326 Main shaft 328 Sub-axis 330 Main guide part 332 Sub-guide part 334 Focus lens drive actuator 350 Image sensor 360 Correction mechanism 362 Image sensor holding frame 362A Image sensor movable holding frame 362B Image sensor base holding frame 364X Image sensor X Axial drive actuator 364Y Image sensor Y Axial drive actuator 366X Image sensor X Axial position detection sensor 366Y Image sensor Y Axial position detection sensor 368 Rigid sphere 368X X Axial position detection magnet 368Y Y-axis direction position detection magnet 370 Spring 380 Position signal acquisition unit 382 Position signal correction unit 384 Position calculation unit 386 Correction information storage unit 388 Zoom position detection unit AL1 Movement trajectory of the first lens group AL2 Movement of the second lens group Trajectory AL3 Movement locus of the third lens group AL4 Movement locus of the fourth lens group G1 First lens group G2 Second lens group G3 Third lens group G3a Third lens group Front group G3b Third lens group Rear group G4 Fourth lens Group G5 Fifth lens group Sim Image plane St Aperture Z Optical axis W1 Graph when the position detection sensor is properly mounted W2 Graph when the position detection sensor is mounted in an inappropriate posture W3 Position detection sensor is inappropriate Graph Wa Graph showing the relationship between the position of the front group of the third lens group at the zoom position a and the output value of the position detection sensor Wb The position and position of the front group of the third lens group at the zoom position b Shows the relationship with the output value of the detection sensor Graphs S1 to S5 Procedure for detecting the position of the front group of the third lens group including correction of the output of the position detection sensor S11 to S16 Processing of drive control of the front group of the third lens group Procedures S21 to S27 Procedures for detecting the position of the front group of the third lens group including correction of the output of the position detection sensor S31 to S35 Procedure for detecting the position of the focus lens including correction of the output of the focus lens position detection sensor.

Claims (26)

Detects a first optical element that is movably supported in a direction parallel to or perpendicular to the optical axis, a first actuator that drives the first optical element, and a magnetic field that changes according to the position of the first optical element. A first unit including a position detection sensor that outputs a signal proportional to the magnitude of the detected magnetic field as a position signal, and
A second unit including a second optical element supported so as to be movable in a direction parallel to or perpendicular to the optical axis, and an electromagnetic second actuator for driving the second optical element.
A unit driving unit that relatively moves the first unit and the second unit along the optical axis, and
When the relative positional relationship between the first unit and the second unit changes, the influence of the magnetism that the position detection sensor receives from the second actuator changes, and the relative of the first unit and the second unit. A position signal correction unit that corrects the position signal output from the position detection sensor according to the specific positional relationship.
Lens barrel with. The unit drive unit relatively moves the first unit and the second unit along the optical axis in response to a zoom operation.
The lens barrel according to claim 1. The position signal correction unit corrects the position signal output from the position detection sensor based on the zoom position.
The lens barrel according to claim 2. The unit drive unit moves the first unit and the second unit along the optical axis by a cam mechanism.
The lens barrel according to any one of claims 1 to 3. The first unit and the second unit are arranged adjacent to each other.
The lens barrel according to any one of claims 1 to 4. The position detection sensor is a hall sensor.
The lens barrel according to any one of claims 1 to 5. The second actuator is a voice coil motor.
The lens barrel according to any one of claims 1 to 6. The second actuator is a moving magnet type voice coil motor.
The position signal correction unit corrects the position signal output from the position detection sensor according to the relative positional relationship between the first unit and the second unit and the position of the second optical element. ,
The lens barrel according to claim 7. The position signal correction unit further corrects the position signal based on the mounting position and / or the mounting posture of the position detection sensor.
The lens barrel according to any one of claims 1 to 8. Equipped with a temperature sensor
The position signal correction unit further corrects the position signal based on the temperature detected by the temperature sensor.
The lens barrel according to any one of claims 1 to 9. Based on the position signal output from the position detection sensor when the first optical element is positioned at the calibration reference position, information necessary for correcting the position signal based on the temperature is acquired.
The lens barrel according to claim 10. When the temperature detected by the temperature sensor exceeds a predetermined allowable range, the position signal correction unit corrects the position signal based on the temperature detected by the temperature sensor.
The lens barrel according to claim 10 or 11. The second unit further includes a second optical element position detecting unit that detects the position of the second optical element.
The lens barrel according to any one of claims 1 to 12. The second optical element position detection unit is
An origin detection unit that detects the movement of the second optical element to a predetermined origin, and
A displacement amount detection unit that detects the displacement amount of the second optical element, and
Have,
The lens barrel according to claim 13. The displacement amount detection unit is formed by an MR sensor.
The lens barrel according to claim 14. In the first unit, the lens, which is the first optical element, is moved in parallel with the optical axis to correct curvature of field.
In the second unit, the lens, which is the second optical element, is moved in parallel with the optical axis to adjust the focus.
The lens barrel according to any one of claims 1 to 15. The lens barrel according to any one of claims 1 to 16 is provided.
Imaging device. A movable lens supported so as to be movable in a direction parallel to or perpendicular to the optical axis, a first actuator for driving the movable lens, and a magnetic field that changes according to the position of the movable lens are detected, and the magnitude of the detected magnetic field is detected. An imaging lens including a movable unit including a position detection sensor that outputs a signal proportional to the value as a position signal, and a movable unit drive unit that moves the movable unit along the optical axis.
An image sensor that is movably supported in a direction orthogonal to the optical axis and captures an optical image of a subject through the imaging lens.
The electromagnetic second actuator that drives the image sensor and
When the relative positional relationship between the movable unit and the image sensor changes, the relative positional relationship between the movable unit and the image sensor changes when the influence of magnetism on the position detection sensor from the second actuator changes. A position signal correction unit that corrects the position signal output from the position detection sensor according to the above.
Imaging device equipped with. The movable unit drive unit moves the movable unit along the optical axis in response to a zoom operation.
The imaging device according to claim 18. The position signal correction unit includes a position signal correction unit that corrects the position signal output from the position detection sensor based on the zoom position.
The imaging device according to claim 19. Detects a first optical element that is movably supported in a direction parallel to or perpendicular to the optical axis, a first actuator that drives the first optical element, and a magnetic field that changes according to the position of the first optical element. A first unit equipped with a position detection sensor that outputs a signal proportional to the magnitude of the detected magnetic field as a position signal, and a second optic that is movably supported in a direction parallel to or perpendicular to the optical axis. A second unit including an element and an electromagnetic second actuator for driving the second optical element is output from the position detection sensor in a lens barrel that moves relatively along the optical axis. A position detection method for detecting the position of the first optical element based on the position signal.
The step of acquiring the position signal output from the position detection sensor and
A step of acquiring information on the relative positional relationship between the first unit and the second unit, and
When the relative positional relationship between the first unit and the second unit changes, the influence of the magnetism that the position detection sensor receives from the second actuator changes, and the relative of the first unit and the second unit. The step of correcting the position signal output from the position detection sensor according to the specific positional relationship, and
Position detection method including. A movable lens supported so as to be movable in a direction parallel to or perpendicular to the optical axis, a first actuator for driving the movable lens, and a magnetic field that changes according to the position of the movable lens are detected, and the magnitude of the detected magnetic field is detected. An imaging lens including a movable unit including a position detection sensor that outputs a signal proportional to the value as a position signal, a movable unit driving unit that moves the movable unit along the optical axis, and the light. In an imaging device including an image sensor that is movably supported in a direction orthogonal to an axis and captures an optical image of a subject via the imaging lens, and an electromagnetic second actuator that drives the image sensor. A position detection method for detecting the position of the movable unit based on the position signal output from the position detection sensor.
The step of acquiring the position signal output from the position detection sensor and
A step of acquiring information on the relative positional relationship between the movable unit and the image sensor, and
When the relative positional relationship between the movable unit and the image sensor changes, the relative positional relationship between the movable unit and the image sensor changes when the influence of magnetism on the position detection sensor from the second actuator changes. The step of correcting the position signal output from the position detection sensor according to
Position detection method including. Detects a first optical element that is movably supported in a direction parallel to or perpendicular to the optical axis, a first actuator that drives the first optical element, and a magnetic field that changes according to the position of the first optical element. A first unit equipped with a position detection sensor that outputs a signal proportional to the magnitude of the detected magnetic field as a position signal, and a second optical that is movably supported in a direction parallel to or perpendicular to the optical axis. A second unit including an element and an electromagnetic second actuator for driving the second optical element is output from the position detection sensor in a lens barrel that moves relatively along the optical axis. A position detection program that causes a computer to execute a process of detecting the position of the first optical element based on the position signal.
The step of acquiring the position signal output from the position detection sensor and
A step of acquiring information on the relative positional relationship between the first unit and the second unit, and
When the relative positional relationship between the first unit and the second unit changes, the influence of the magnetism that the position detection sensor receives from the second actuator changes, and the relative of the first unit and the second unit. The step of correcting the position signal output from the position detection sensor according to the specific positional relationship, and
A position detection program that includes. A movable lens supported so as to be movable in a direction parallel to or perpendicular to the optical axis, a first actuator for driving the movable lens, and a magnetic field that changes according to the position of the movable lens are detected, and the magnitude of the detected magnetic field is detected. An imaging lens including a movable unit including a position detection sensor that outputs a signal proportional to the value as a position signal, a movable unit driving unit that moves the movable unit along the optical axis, and the light. In an imaging device including an image sensor that is movably supported in a direction orthogonal to an axis and captures an optical image of a subject via the imaging lens, and an electromagnetic second actuator that drives the image sensor. A position detection program that causes a computer to execute a process of detecting the position of the movable unit based on the position signal output from the position detection sensor.
The step of acquiring the position signal output from the position detection sensor and
A step of acquiring information on the relative positional relationship between the movable unit and the image sensor, and
When the relative positional relationship between the movable unit and the image sensor changes, the relative positional relationship between the movable unit and the image sensor changes when the influence of magnetism on the position detection sensor from the second actuator changes. The step of correcting the position signal output from the position detection sensor according to
A position detection program that includes. A non-temporary, computer-readable storage medium when the instructions stored in the recording medium are read by a computer.
Detects a first optical element that is movably supported in a direction parallel to or perpendicular to the optical axis, a first actuator that drives the first optical element, and a magnetic field that changes according to the position of the first optical element. A first unit equipped with a position detection sensor that outputs a signal proportional to the magnitude of the detected magnetic field as a position signal, and a second optic that is movably supported in a direction parallel to or perpendicular to the optical axis. A second unit including an element and an electromagnetic second actuator for driving the second optical element is output from the position detection sensor in a lens barrel that moves relatively along the optical axis. It is a position detection function that detects the position of the first optical element based on the position signal.
A function to acquire the position signal output from the position detection sensor and
A function for acquiring information on the relative positional relationship between the first unit and the second unit, and
When the relative positional relationship between the first unit and the second unit changes, the influence of the magnetism that the position detection sensor receives from the second actuator changes, and the relative of the first unit and the second unit. A function to correct the position signal output from the position detection sensor according to the specific positional relationship, and
A storage medium that allows a computer to realize a position detection function including. A non-temporary, computer-readable storage medium when the instructions stored in the recording medium are read by a computer.
A movable lens supported so as to be movable in a direction parallel to or perpendicular to the optical axis, a first actuator for driving the movable lens, and a magnetic field that changes according to the position of the movable lens are detected, and the magnitude of the detected magnetic field is detected. An imaging lens including a movable unit including a position detection sensor that outputs a signal proportional to the value as a position signal, a movable unit driving unit that moves the movable unit along the optical axis, and the light. In an imaging device including an image sensor that is movably supported in a direction orthogonal to an axis and captures an optical image of a subject via the imaging lens, and an electromagnetic second actuator that drives the image sensor. It is a position detection function that detects the position of the movable unit based on the position signal output from the position detection sensor.
A function to acquire the position signal output from the position detection sensor and
A function to acquire information on the relative positional relationship between the movable unit and the image sensor, and
When the relative positional relationship between the movable unit and the image sensor changes, the relative positional relationship between the movable unit and the image sensor changes when the influence of magnetism on the position detection sensor from the second actuator changes. The function of correcting the position signal output from the position detection sensor according to
A storage medium that allows a computer to realize a position detection function including.

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