WO2020022026A1

WO2020022026A1 - Lens barrel, imaging device, position detection method, and position detection program

Info

Publication number: WO2020022026A1
Application number: PCT/JP2019/026687
Authority: WO
Inventors: 伸一郎藤木; 真彦宮田
Original assignee: 富士フイルム株式会社
Priority date: 2018-07-26
Filing date: 2019-07-04
Publication date: 2020-01-30
Also published as: JPWO2020022026A1; JP6889334B2

Abstract

Provided are: a lens barrel that makes it possible to precisely detect the position of an object to be detected; an imaging device; a position detection method; and a position detection program. The lens barrel (200) is provided with: a first lens unit (220) provided with a position detection sensor configured from a hole sensor; and a second lens unit (240) provided with an electromagnetic actuator. When the relative positional relationship of the first lens unit (220) and the second lens unit (240) is changed by zooming, the output of the position detection sensor provided to the first lens unit (220) is corrected in accordance with the relative positional relationship of the first lens unit (220) and the second lens unit (240).

Description

Lens barrel, imaging device, position detection method, and position detection program

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

技術 A technology 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 / Magnetoresistance effect sensor) is known. However, if 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 using electromagnetic force), the magnetic sensor will be affected by magnetism from the actuator (magnetic interference). As a result, there is a problem that the position detection accuracy is reduced. In order to solve this problem, conventionally, a magnetic sensor and an actuator are sufficiently separated from each other (for example, Patent Document 1 and the like), or a magnetic shielding member is disposed between the magnetic sensor and the actuator (for example, Patent Document 1). 2) to prevent a decrease in detection accuracy.

International Publication No. 2016/006168 JP 2008-15159 A

影響 The effect of the electromagnetic actuator on the magnetic sensor varies depending 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 disadvantage that the target position cannot be accurately detected unless the change in the distance is considered.

The present invention has been made in view of such circumstances, and has as its object to provide a lens barrel, an imaging device, a position detection method, and a position detection program capable of accurately detecting the position of a detection target.

手段 The means for solving the above problems are as follows.

(1) A first optical element movably supported in a direction parallel or perpendicular to the optical axis, a first actuator for driving 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 optical element movably supported in a direction parallel or perpendicular to the optical axis. A second unit including: an electromagnetic type second actuator that drives the second optical element; a unit driving unit that relatively moves the first unit and the second unit along the optical axis; A lens barrel comprising: a position signal correction unit configured to correct a position signal output from the position detection sensor according to a relative positional relationship between the unit and the second unit.

According to this aspect, by moving the first unit and the second unit relatively along the optical axis, when the relative positional relationship between them changes, the relative positional relationship (distance relationship and The position signal output from the position detection sensor is corrected in accordance with the definition. Thereby, the position of the first optical element to be detected can be accurately detected.

すると 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 magnetism on the position detection sensor from the second actuator changes, and the output of the position detection sensor changes. Therefore, even when 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 characteristic of the position detection sensor does not change. Accordingly, the output of the position detection sensor is corrected. Thereby, even if 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 method of driving by the unit driving unit may be manual or electric.

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

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

(3) The lens barrel according to (2), wherein the position signal correction unit corrects the position signal output from the position detection sensor based on the zoom position.

場合 When the first unit and the second unit move 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 the present embodiment, the output of the position detection sensor is corrected based on the zoom position. This makes it possible to more easily correct the output of the position detection sensor.

(4) The lens barrel according to any one of (1) to (3), wherein the unit driving section moves the first unit and the second unit along the optical axis by a cam mechanism.

According to this aspect, the unit driving section 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), 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), wherein the position detection sensor is a hall sensor.

According to this aspect, the position detection sensor is constituted by the 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 a position detection sensor, the position detection sensor is affected by magnetism from the second actuator, and thus the present invention works effectively.

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

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

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

According to this aspect, the second actuator is constituted by a moving magnet type voice coil motor. A moving magnet type voice coil motor is a type of voice coil motor in which a magnet moves in a magnetic field generated by a yoke and a coil. Therefore, in this case, the magnet is provided in the second optical element which is a movable component. If 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 aspect, 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 that is the position of the magnet. Thereby, the position of the first optical element to be detected can be accurately detected.

(9) The lens barrel according to any one of (1) to (8), wherein the position signal correction unit further corrects the position signal based on a mounting position and / or a mounting posture of the position detection sensor.

出力 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 mounting posture of the position detection sensor. Thereby, the position of the first optical element to be detected can be detected with higher accuracy.

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

出力 The output of the position detection sensor 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. Thereby, the position of the first optical element to be detected can be detected with higher accuracy.

(11) 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 based on (10). ) Lens barrel.

According to this aspect, 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 located at the calibration reference position. This makes it possible to easily acquire information (particularly, an offset amount) necessary for correcting the position signal based on the temperature. As the calibration reference position, for example, a movable end on one side of the first optical element (an end on one side of the movable range) can be adopted.

(12) The position signal correction section 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. Or the lens barrel of (11).

According to this aspect, the correction based on the temperature is performed only when the temperature detected by the temperature sensor exceeds a predetermined allowable range. Accordingly, the correction based on the temperature is performed only when the correction is truly required, so that the overall processing load can be reduced.

(13) The lens barrel according to any one of (1) to (12), wherein the second unit further includes a second optical element position detecting unit that detects a position of the second optical element.

According to this aspect, the second unit is provided with the second optical element position detection unit that detects the position of the second optical element. Thereby, the position of the second optical element in the second unit can be detected.

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

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

(15) The lens barrel according to the above (14), wherein the displacement amount detection unit is constituted by an MR sensor.

According to this aspect, the displacement amount detection unit is configured by an MR sensor (Magneto Resistance Sensor).

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

According to this aspect, in the first unit, the field curvature is corrected by moving the lens as the first optical element in parallel with the optical axis. In the second unit, the focal point is adjusted by moving the lens, which is the second optical element, in parallel with the optical axis.

(17) An imaging apparatus including the lens barrel according to any one of (1) to (16).

According to this aspect, the lens barrel of the imaging device is provided with any one of the lens barrels (1) to (16).

(18) A movable lens supported movably in a direction parallel 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 is detected. A position detection sensor that outputs a signal proportional to the size as a position signal, and a movable unit including: a movable unit driving unit that moves the movable unit along the optical axis; an imaging lens including: an optical axis; An image sensor that is movably supported in the orthogonal direction and captures an optical image of a subject via an imaging lens, an electromagnetic second actuator that drives the image sensor, and a relative positional relationship between the movable unit and the image sensor And a position signal correction unit that corrects a position signal output from the position detection sensor in accordance with (1).

According to this aspect, when the relative positional relationship between the movable unit and the image sensor changes by moving the movable unit relatively along the optical axis, the position is determined according to the relative positional relationship. The position signal output from the detection sensor is corrected. Thereby, the position of the movable lens to be detected can be accurately detected.

(19) The imaging device according to (18), wherein the movable unit driving unit moves the movable unit along the optical axis in response to a zoom operation.

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

(20) The position signal correction unit for correcting the position signal output from the position detection sensor based on the zoom position, and the imaging device according to (19).

場合 When the movable unit moves 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 the present embodiment, the output of the position detection sensor is corrected based on the zoom position. This makes it possible to more easily correct the output of the position detection sensor.

(21) A first optical element movably supported in a direction parallel or perpendicular to the optical axis, a first actuator for driving the first optical element, and a magnetic field that changes according to the position of the first optical element. 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 unit movably supported in a direction parallel or perpendicular to the optical axis. A second unit including an element and an electromagnetic second actuator for driving a second optical element is configured to generate a position signal output from a position detection sensor in a lens barrel relatively moving along an optical axis. A position detecting method for detecting a position of the first optical element based on the position information, the step of obtaining a position signal output from the position detecting sensor, and the step of obtaining information on a relative positional relationship between the first unit and the second unit. get Step and, depending on the relative positional relationship between the first unit and second unit, the position detecting method comprising the steps of correcting the position signal output from the position detection sensor.

According to this aspect, when the first unit including the position detection sensor and the second unit including the electromagnetic actuator (the second actuator) relatively move along the optical axis, the first unit includes 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 information on the positional relationship. Thereby, even if 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 movably supported in a direction parallel 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. A position detection sensor that outputs a signal proportional to the size as a position signal, and a movable unit including: a movable unit driving unit that moves the movable unit along the optical axis; an imaging lens including: an optical axis; An image sensor that is movably supported in a direction orthogonal to the image sensor and captures an optical image of a subject via an imaging lens, and an electromagnetic second actuator that drives the image sensor; A position detection method for detecting a position of a movable unit based on a position signal output, the method comprising: obtaining a position signal output from a position detection sensor. Acquiring information on the relative positional relationship between the movable unit and the image sensor; and correcting the position signal output from the position detection sensor according to the relative positional relationship between the movable unit and the image sensor. And a position detection method including:

According to this aspect, when the movable unit including the position detection sensor moves relatively to the image sensor driven by the electromagnetic actuator (second actuator), the relative position of the movable unit and the image sensor is increased. The information of the positional relationship is acquired, and the output of the position detection sensor is corrected based on the acquired information of the positional relationship. Thus, 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 accurately detected.

(23) A first optical element movably supported in a direction parallel or perpendicular to the optical axis, a first actuator for driving the first optical element, and a magnetic field that varies according to the position of the first optical element. 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 unit movably supported in a direction parallel or perpendicular to the optical axis. A second unit including an element and an electromagnetic second actuator for driving a second optical element is configured to generate a position signal output from a position detection sensor in a lens barrel relatively moving along an optical axis. A position detection program that causes a computer to execute a process of detecting a position of the first optical element based on the first and second units; Detecting the relative positional relationship between the first unit and the second unit, and correcting the position signal output from the position detecting sensor according to the relative positional relationship between the first unit and the second unit. program.

(24) A movable lens supported movably in a direction parallel 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 is detected. A position detection sensor that outputs a signal proportional to the size as a position signal, and a movable unit including: a movable unit driving unit that moves the movable unit along the optical axis; an imaging lens including: an optical axis; An image sensor that is movably supported in a direction orthogonal to the image sensor and captures an optical image of a subject via an imaging lens, and an electromagnetic second actuator that drives the image sensor; A position detection program for causing a computer to execute a process of detecting the position of the movable unit based on the output position signal, the position detection program comprising: Obtaining a position signal output from the position detection sensor, obtaining information on a relative positional relationship between the movable unit and the image sensor, and Correcting the output position signal.

According to the present invention, the position of the detection target can be accurately detected.

1 is a plan view showing an embodiment of an interchangeable lens to which the present invention is applied. Rear view of the interchangeable lens shown in FIG. FIG. 3 is a cross-sectional view taken along the line 3-3 when the zoom operation is performed to the wide end. FIG. 4 is a sectional view taken along line 4-4 of FIG. 2 when zooming to the wide end. FIG. 4 is a sectional view taken along line 4-4 of FIG. 2 when zooming to the telephoto end. 6-6 sectional view of FIG. 7-7 sectional view of FIG. Diagram showing the movement of each lens group when zoom operation is performed Sectional drawing which shows the support structure of a 3rd lens group movable holding frame and a 4th lens group movable holding frame. Sectional drawing which shows the mounting structure of the 3rd lens group front group drive actuator. Sectional drawing which shows the mounting structure of a 4th lens group drive actuator. Block diagram showing the electrical configuration of the interchangeable lens FIG. 4 is a diagram schematically illustrating a positional relationship between a third lens unit and a fourth lens unit at a wide end. The figure which shows typically the positional relationship of the 3rd lens group and the 4th lens group at a telephoto end. 4 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. A block having a configuration related to a process of detecting the position of the front group of the third lens group including the correction of the output of the position detection sensor. 9 is a flowchart illustrating a procedure of a process of detecting the position of the front group of the third lens group including the correction of the output of the position detection sensor. 4 is a flowchart showing the procedure of drive control processing for the front group of the third lens group. Diagram showing the mounting state of the position detection sensor when properly mounted Diagram showing the mounting state of the position detection sensor when improperly mounted 7 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. FIG. 6 is a block diagram of a configuration related to a process of detecting the position of the front group of the third lens group when correcting the output of the position detection sensor based on temperature Conceptual diagram of acquisition method of intercept correction coefficient based on temperature Sectional drawing which shows the schematic structure of an interchangeable lens when a 4th lens group drive actuator is comprised by a moving magnet type VCM. FIG. 6 is a block diagram of a configuration related to a process of detecting the position of the front group of the third lens group including the correction of the output of the position detection sensor. 9 is a flowchart illustrating a procedure of a process of detecting the position of the front group of the third lens group including the correction of the output of the position detection sensor. Sectional drawing which shows an example of a lens barrel provided with a lens moving in a direction perpendicular to the optical axis and a lens moving in a direction parallel to the optical axis. 28-28 sectional view of FIG. 27-29 sectional view of FIG. Schematic configuration diagram of an imaging device to which the present invention is applied 31-31 sectional view of FIG. 30 FIG. 30 is a sectional view taken along line 32-32 of FIG. FIG. 3 is a block diagram of a correction function of an output of a focus lens position detection sensor provided by a control unit of the imaging device. 4 is a flowchart showing a procedure of a focus lens position detection process including correction of an output of a focus lens position detection sensor.

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

[First Embodiment]
Here, a case where the present invention is applied to an interchangeable lens of an interchangeable lens type camera will be described as an example. This type of interchangeable lens is detachably attached to a 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 (view from the mount side) of the interchangeable lens shown in FIG. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2 when the zoom operation is performed to the wide end. FIG. 4 is a sectional view taken along line 4-4 in FIG. 2 when the zoom operation is performed to the wide end. FIG. 5 is a cross-sectional view taken along line 4-4 of FIG. 2 when the zoom operation is performed to the telephoto end. FIG. 6 is a sectional view taken along line 6-6 of FIG. FIG. 7 is a sectional view taken along the line 7-7 in FIG.

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

[Outer body]
The exterior body 2 has a cylindrical shape, accommodates the lens barrel main body 10 inside thereof, and covers the outer periphery of the lens barrel main body 10. The exterior body 2 includes a focus ring 3 as a focus operation member, a zoom ring 4 as a zoom operation member, and an aperture ring 5 as 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 changes continuously within a predetermined range. By rotating the aperture ring 5, the aperture value (F value) is switched at predetermined steps.

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

The fixed cylinder 12 has a mount 16 at its rear end (the end on the image plane side). The mount 16 is constituted by 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 barrel 14 also rotates in conjunction with the rotation.

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

絞り Aperture St is arranged inside fixed cylinder 12. The stop St is arranged between the first lens group G1 and the second lens group G2.

FIG. 8 is a diagram illustrating a moving state of each lens group when a zoom operation is performed. In the same figure, (A) shows the lens arrangement at the wide end, and (B) shows the lens arrangement at the tele end. Curves indicated by reference signs AL1 to AL4 indicate the movement trajectories of the lens groups that are moved by the zoom operation. Specifically, reference symbol AL1 denotes a movement locus of the first lens group G1, reference sign AL2 denotes a movement locus of the second lens group G2, reference sign AL3 denotes a movement locus of the third lens group G3, and reference sign AL4 denotes a movement locus of the fourth lens group G4. The moving locus is shown.

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 a zoom operation. On the other hand, the fifth lens group G5 is a lens group fixed to the image plane Sim by a zoom operation. The stop St moves integrally with the second lens group G2.

３As 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 front third lens group G3a is a lens group for correcting the curvature of field, and corrects the curvature of field by moving along the optical axis Z. For this reason, the third lens group front group G3a is configured to be movable independently, independently of the other lens groups.

{Circle around (4)} The fourth lens group G4 is a lens group for focus adjustment, and adjusts the focus by moving along the optical axis Z. For this reason, the fourth lens group G4 is configured to be independently movable independently of the other lens groups.

移動 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 barrel 14 into a linear motion, and moves each lens group along the optical axis Z. In the interchangeable lens 1 according to the present embodiment, the cam mechanism includes a fixed barrel 12 having a rectilinear groove, a cam barrel 14 having a cam groove, and a cam follower provided in a holding frame of each lens group. You. Each of the first to fourth lens groups G1 to G4 is moved by a cam mechanism along predetermined movement trajectories AL1 to AL4. The cam mechanism is an example of a unit driving 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, is disposed in the fixed barrel 12, and passes through the fixed barrel 12 along the optical axis Z. Supported movably in a 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 is fitted into a first lens group zoom drive cam groove 14A provided in the cam barrel 14 and a first lens group zoom drive straight drive groove 12A provided in the fixed barrel 12, respectively. Are combined.

により With the above configuration, the first lens group G1 is held in the fixed barrel 12. When the cam barrel 14 is rotated by the zoom ring 4, the first lens group G1 moves along the optical axis Z in the fixed barrel 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, is disposed in the fixed barrel 12, and passes through the fixed barrel 12 along the optical axis Z. Supported movably in a direction parallel to

The second lens group holding frame 22 is provided with three second lens group zoom drive cam followers 34 on its outer peripheral portion. The three second lens group zoom driving cam followers 34 are arranged at equal intervals in the circumferential direction. Each of the second lens group zoom drive cam followers 34 is fitted into the second lens group zoom drive cam groove 14B provided in the cam barrel 14 and the second lens group zoom drive straight advance groove 12B provided in the fixed barrel 12, respectively. Are combined.

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

As shown in FIGS. 3, 4, and 5, an aperture unit 30 constituting the aperture St is assembled to the second lens group holding frame 22. Thus, the stop St is disposed in the fixed barrel 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 G 3 is held by the third lens group holding frame 24, is arranged in the fixed barrel 12, and moves inside the fixed barrel 12. It is movably supported in a direction parallel to the optical axis Z.

The third lens group holding frame 24 includes 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 front group G3a of the third lens group is held by the third lens group movable holding frame 24B. The third lens group rear group G3b is held by the third lens group base holding frame 24A.

カム 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 of the third lens group zoom drive cam followers 36 is fitted into a third lens group zoom drive cam groove 14C provided in the cam barrel 14 and a third lens group zoom drive straight advance groove 12C provided in the fixed barrel 12. Are combined. Thereby, the third lens group base holding frame 24 A is held in the fixed barrel 12. When the cam barrel 14 is rotated by the zoom ring 4, the third lens group base holding frame 24A moves along the optical axis Z in the fixed barrel 12.

１A 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 shaft 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, they are 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 cylindrical shape, and has sliding portions 52A at both ends in the axial direction. The sliding portion 52A has an inner diameter corresponding to the outer diameter of the first main shaft 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 54A at the 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. Accordingly, the third lens group base holding frame 24A is movably supported along the optical axis Z.

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

The third lens group front group drive actuator 56 is constituted by a moving magnet type (movable magnet type) voice coil motor (Voice Coil Motor: VCM). The moving magnet type VCM is a VCM in which a magnet moves in a magnetic field generated by a yoke and a 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 constituted by the moving magnet type VCM. The third lens group base holding frame 24A is provided with a driving coil 56C and a plurality of outer yokes 56D constituting a moving magnet type VCM.

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

As shown in the figure, the driving coil 56C is wound around the outer periphery of the third lens group movable holding frame 24B, and is attached to the inner periphery 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.

(4) The plurality of driving magnets 56A are arranged in two groups. Specifically, the two groups are arranged symmetrically with respect to a straight line L passing through the optical axis Z in a cross section orthogonal to the optical axis Z. On this straight line L, a first main shaft 48 and a first sub shaft 50 are arranged. Therefore, the two groups of the driving magnets 56 A are arranged symmetrically 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 driving magnets 56A are provided, and the six driving magnets 56A are divided into two groups and arranged. 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.

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

A plurality of outer yokes 56D are arranged corresponding to a plurality of inner yokes 56B. Each outer yoke 56D is arranged to face the corresponding inner yoke 56B with the driving coil 56C interposed therebetween.

により With the above configuration, the third lens group G3 is held in the fixed barrel 12. When the cam barrel 14 is rotated by the zoom ring 4, the third lens group G3 moves along the optical axis Z in the fixed barrel 12 by the action of the cam mechanism. That is, the third lens group front group G3a and the third lens group rear group G3b move in the fixed cylinder 12 along the optical axis Z as a unit. Further, when the third lens group front group drive actuator 56 is driven, the third lens group front group G3a moves alone along the optical axis Z. The third lens group front group drive actuator 56 moves the third lens group front group G3a by itself, thereby correcting the field curvature.

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

The fourth lens group holding frame 26 includes 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.

４The 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. The fourth lens group zoom drive cam followers 38 are fitted into the fourth lens group zoom drive cam grooves 14D provided in the cam barrel 14 and the fourth lens group zoom drive straight advance grooves 12D provided in the fixed barrel 12, respectively. Are combined. Thus, the fourth lens group base holding frame 26A is held in the fixed barrel 12. When the cam barrel 14 is rotated by the zoom ring 4, the fourth lens group base holding frame 26A moves in the fixed barrel 12 along the optical axis Z.

２A 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 shaft 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 a circle centered on the optical axis Z. Accordingly, the second main shaft 58 and the second sub shaft 60 are arranged on the same straight line as the first main shaft 48 and the first sub shaft 50 in a cross section orthogonal to the optical axis Z. Here, the term “identical” includes a range recognized as being substantially identical.

The fourth lens group movable holding frame 26 B 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.

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

２The second sub-guide portion 64 has a U-shaped groove 64A at the tip. The groove portion 64 A of the second sub guide portion 64 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. Thereby, the fourth 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 a second actuator. The fourth lens group G4 is an example of a second optical element.

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

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

The plurality of fourth lens group drive actuators 68 are divided into two groups and arranged. Specifically, the two groups are arranged symmetrically with respect to a 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 arranged symmetrically with respect to the straight line L passing through the second main axis 58 and the second auxiliary axis 60.

In the present embodiment, four fourth lens group drive actuators 68 are provided, and the four fourth lens group drive actuators 68 are divided into two groups and arranged. 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 section 70 on the outer periphery thereof, and the coil holding section 70 holds a driving coil 68A of each fourth lens group drive actuator 68.

The inner yoke 68C and the outer yoke 68D of each fourth lens group drive actuator 68 are arranged to face each other with the drive coil 68A interposed therebetween. The inner yoke 68C and the outer yoke 68D are integrally formed. The integrally formed inner yoke 68C and outer yoke 68D are arranged at predetermined positions with the outer yoke 68D being held by 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 barrel 12. Further, when the cam barrel 14 is rotated by the zoom ring 4, the fourth lens group G4 moves along the optical axis Z in the fixed barrel 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 alone along the optical axis Z. By moving the fourth lens group G4 by itself by the fourth lens group drive actuator 68, focus adjustment is performed.

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

[Position detection structure of each lens group]
[Position of each lens group by zoom operation]
By the zoom operation, each of the first to fourth lens groups G1 to G4 moves along predetermined movement trajectories 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 Third Lens Group Front Group G3a and Fourth Lens Group G4]
The front group G3a and the fourth lens group G4 of the third lens group 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 detector 80, and the position of the fourth lens group G4 is detected by the fourth lens group position detector 90. .

[Third lens group front group position detector]
The third lens group front group position detecting section 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 a 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 front position detection unit 80 of the third lens group detects the position detection magnet 82 provided in the third lens group movable holding frame 24B and the position of the position detection magnet 82. And a position detection sensor 84 that operates. In particular, in the present embodiment, the position detection sensor 84 is configured by a Hall sensor that 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 on the third lens group base holding frame 24A. The position detection sensor 84 is disposed at the installation position of the first sub shaft 50 in a cross section orthogonal to the optical axis Z, as shown in FIGS. More specifically, they are arranged on a straight line L passing through the optical axis Z and the first sub-axis 50. The position detection sensor 84 is disposed behind the first sub shaft 50 (on the image surface side) in a cross section parallel to the optical axis Z, as shown in FIGS.

The position detecting magnet 82 is provided on the third lens group movable holding frame 24B. The position detecting magnet 82 is arranged close to the position detecting 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 disposed at the installation position, and faces the position detection sensor 84 with a predetermined gap. Placed. As a result, the position detecting magnet 82 and the position detecting 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 detecting unit 80 having the above configuration, the position of the position detecting magnet 82 provided in the third lens group movable holding frame 24B is detected by the position detecting sensor 84, so that the third The position of the front lens group G3a is detected.

[Fourth lens group position detector]
The fourth lens group position detecting section 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 detector 90 is an example of a second optical element position detector.

The fourth lens group position detector 90 includes an origin detector 92 that detects that the fourth lens group G4 is located at the origin, and a displacement detector 94 that detects the displacement of the fourth lens group G4. Is done. The fourth lens group position detecting section 90 detects that the fourth lens group G4 is located at the origin by the origin detecting section 92, detects the displacement from the origin by the displacement detecting section 94, and outputs the fourth lens group. The position of G4 is detected.

原点 As shown in FIGS. 7 and 11, the origin detecting unit 92 includes a light blocking plate 92A and a photo interrupter 92B. The light blocking 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 detecting 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 (the fourth lens group G4 is detected by detecting the light shielding by the light shielding plate 92A). Is located at the origin.) Therefore, the light shielding plate 92A and the photo interrupter 92B are installed such 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 detected at the timing when the fourth lens group G4 is located at the origin). 92A is installed so as to shield the photo interrupter 92B from light.)

As shown in FIG. 3, FIG. 7, and FIG. 11, the displacement amount detection unit 94 includes a magnetic scale 94A and an MR sensor (Magneto Resistive Sensor; magnetoresistive element) for detecting the N pole and the S pole of the magnetic scale 94A. 94B. The MR sensor 94B is one of the magnetic sensors.

The magnetic scale 94A has a bar shape, and has a structure in which N poles and S poles are magnetized at a constant pitch along the longitudinal direction. The magnetic scale 94A is provided on the second main guide portion 62, and is arranged along the moving direction of the fourth lens group G4. That is, they are 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 close to the magnetic scale 94A. More specifically, as shown in FIG. 11, in a cross section orthogonal to the optical axis Z, it is arranged at the installation position of the second main guide portion 62, and is arranged to face the magnetic scale 94A with a predetermined gap. You. 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 detecting section 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 section 62 with the photo interrupter 92B. Is detected. The displacement of the second main guide portion 62 is detected by the MR sensor 94B via the magnetic scale 94A, whereby the displacement of the fourth lens group G4 is detected. The photo interrupter 92B detects that the fourth lens group G4 is located at the origin, and the MR sensor 94B detects the amount of displacement from the origin, thereby detecting the position of the fourth lens group G4 with respect to the origin.

[Drive system layout for sensors]
As described above, the position detection sensor 84 is disposed at the position of the first sub shaft 50 in a cross section orthogonal to the optical axis Z (see FIG. 10). The MR sensor 94B is disposed at the position of the second main guide portion 62 in a 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 main axis 48 and the first sub-axis 50 and the second main axis 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, the third lens group front group drive actuator 56 that drives the third lens group front group G3a includes a plurality of driving magnets 56A, a plurality of inner yokes 56B, and a plurality of outer yokes 56D, which are constituent elements thereof. In a cross section orthogonal to Z, they are 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 body are arranged symmetrically with respect to a straight line L passing through the optical axis Z in a cross section orthogonal to the optical axis Z.

The plurality of fourth lens group drive actuators 68 that drive the fourth lens group G4 are symmetrically arranged with respect to a 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 body are arranged symmetrically with respect to a straight line L passing through the optical axis Z in a 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 material are symmetrically arranged with respect to the position detection sensor 84 and the MR sensor 94B in a cross section orthogonal to the optical axis Z. As a result, the influence of each magnetic sensor on each sensor can be made uniform, and more accurate detection can be performed.

In addition, in the interchangeable lens 1 of the present embodiment, the first main shaft 48 and the first sub shaft 50 are arranged on the inner diameter side than the second main shaft 58 and the second sub shaft 60. This makes it possible to stably support a movable lens group with a compact configuration. That is, by disposing the positions of the first main shaft 48 and the first sub shaft 50 in the radial direction with respect to the second main shaft 58 and the second sub shaft 60, the size in the optical axis direction can be enlarged as a whole. Instead, the lengths of the first main shaft 48 and the second main shaft 58 can be secured. Thereby, the third lens group front group G3a and the fourth lens group G4 can be stably supported. That is, since the lengths of the first main shaft 48 and the second main shaft 58 can be increased, 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 Group G4 can be stably supported.

Even when the magnetic body is symmetrically arranged with respect to each sensor as described above, if the positional relationship with the magnetic body changes, the detection accuracy is reduced due to the influence of the change. . In particular, since the Hall sensor is configured to detect an absolute position, if the positional relationship between the Hall sensor and the magnetic body changes, the detection accuracy is reduced due to 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 by zooming. Therefore, the output of the position detection sensor 84 is corrected according to the change in the positional relationship due to the zoom. This will be described in detail later.

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

The interchangeable lens 1 includes a third lens group front group drive unit 110 that drives the third lens group front group G3a, a third lens group front group position detection unit 80 that detects the position of the third lens group front group G3a, and a fourth A fourth lens group drive section 112 for driving the lens group G4, a fourth lens group position detection section 90 for detecting the position of the fourth lens group G4, an aperture drive section 114 for driving the aperture St, and detecting the temperature inside the interchangeable lens Temperature detector 116, a focus operation detector 118 for detecting a focus operation, a zoom position detector 120 for detecting a zoom position, an aperture setting detector 122 for detecting an aperture setting, and an overall control of the entire operation of the interchangeable lens 1. And a lens control unit 100 that performs the operation.

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

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. 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 in accordance with the position of the position detection magnet 82, and outputs a signal proportional to the detected magnetic field to the position signal of the third lens group front group G3a. Is output to the lens control unit 100. The lens control unit 100 processes a signal output from the position detection sensor 84 to detect the position of the third front lens group G3a. At this time, processing is performed in consideration of the positional relationship between the position detection sensor 84 and the fourth lens group drive actuator 68 to detect the position of the third lens group front group G3a.

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

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

The aperture driving unit 114 includes an aperture driving actuator (not shown) for driving the aperture St, and a driving circuit therefor. The aperture drive actuator is formed of, for example, a step motor. The aperture driving unit 114 drives an aperture driving actuator in accordance with a command from the lens control unit 100 to expand and contract the aperture St.

The temperature detecting section 116 includes a temperature sensor (not shown), and detects the temperature inside the interchangeable lens by the temperature sensor. The temperature sensor is provided in the aperture unit 30, for example. Temperature detecting section 116 outputs information on the temperature inside the interchangeable lens detected by the temperature sensor to lens control section 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 a focus operation amount based on an output from the focus operation detection unit 118.

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

The aperture setting detector 122 detects the setting position of the aperture ring 5 and outputs the detection result to the lens controller 100. The lens control unit 100 detects a set aperture value (F value) based on an output from the aperture setting detection unit 122. Note that 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 operation 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 to move the fourth lens group G4 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 detector 90.

In addition, 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 Is moved 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. In addition, 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 detecting section 90.

Further, based on the aperture value switched by operating the aperture ring 5, the aperture driving unit 114 is driven to operate the aperture St.

The lens control unit 100 controls the operation of each unit according to a command from a camera to which the interchangeable lens 1 is attached. For example, the fourth lens group drive actuator 68 is driven based on autofocus information from the camera to move the fourth lens group G4 to a predetermined position. In addition, the aperture driving unit 114 is driven based on the aperture setting information from the camera 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 for each unit from the camera control unit 130. Further, the control unit 130 transmits zoom setting information, aperture setting information, focus position information, and the like to the camera control unit 130. Communication between the lens control unit 100 and the camera control unit 130 is performed via a terminal 16A provided on the mount 16 (see FIG. 2).

(4) The lens controller 100 drives the third lens group front group drive actuator 56 based on the temperature detected by the temperature sensor to move the third lens group front group G3a to a predetermined position. Thereby, the field curvature caused by the temperature change is corrected.

The lens control unit 100 is composed of, for example, a computer having a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), and executes a predetermined program. And implement various control functions.

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

３The third lens group G3 and the fourth lens group G4 are adjacent to each other. The third lens group G3 and the fourth lens group G4 are both lens groups that are moved by a zoom operation. However, the amounts of movement by zoom are different from each other. Therefore, the relative positional relationship between the third lens group G3 and the fourth lens group G4 is changed by the zoom operation. Specifically, the position changes gradually from the wide end to 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 are farthest apart at the telephoto end (see FIG. 14).

As the relative positional relationship between the third lens group G3 and the fourth lens group G4 changes, the third lens group G3 and the fourth lens group G4 are provided with the position detection sensor 84 provided in the third lens group holding frame 24 and the fourth lens group holding frame 26. The positional relationship with the fourth lens group drive actuator 68 also changes. As a result, the influence of the magnetism received by the position detection sensor 84 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 indicates the position of the third lens group front group G3a, and the horizontal axis indicates the output value of the position detection sensor 84.

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

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

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 parallel to the optical axis Z by the zoom operation. Further, the fourth lens group G4, the fourth lens group drive actuator 68, and the fourth lens group position detecting section 90 constitute one unit based on the fourth lens group holding frame 26, and this unit is operated by a zoom operation. It moves parallel to the optical axis Z. A unit based on the third lens group holding frame 24 is an example of a first unit, and a unit based on the fourth lens group holding frame 26 is an example of a second unit.

[Configuration Related to Processing for Detecting Position of Front Group of Third Lens Group Including Correction of Output of Position Detection Sensor]
FIG. 16 is a block diagram of a configuration related to a process of detecting the position of the front group of the third lens group including the correction of the output of the position detection sensor.

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

The lens control unit 100 executes a predetermined control program (position detection program), thereby obtaining a position signal, a position signal acquisition unit 140 for acquiring a position signal, a position signal correction unit 142 for correcting the acquired position signal, and 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 obtained.

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 information on the zoom position from the zoom position detection unit 120, and acquires information on a correction coefficient corresponding to the acquired zoom position from the correction information storage unit 146. Then, the position signal is corrected based on the obtained correction coefficient.

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

Now, 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 (the solid line graph Wa in FIG. 15). Can be approximated as y = A (a) x + B (a). Further, the position of the front group G3a of the third lens group at the zoom position b (the broken line graph Wb, a ≠ b in FIG. 15) can be approximated as y = A (b) x + B (b). Here, A (a) is the inclination (sensor output sensitivity) at the zoom position a, and B (a) is the intercept (sensor output bias) at the zoom position a. A (b) is the inclination (sensor output sensitivity) at the zoom position b, and B (b) is the intercept (sensor output bias) at the zoom position b.

When the output of the position detection sensor 84 at the zoom position a is set as a 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 as to have the same output value.

In the case of the zoom position b, if α = A (a) / A (b) and β = [B (a) −B (b)] / A (b), the corrected output value of the position detection sensor 84 ( The position signal) X can be calculated by a 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, and are stored in the correction information storage unit 146 in association with the zoom position information. The correction information storage unit 146 is configured by a ROM of a computer constituting 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, by acquiring information on the zoom position, the position detection sensor 84 and the fourth lens group drive are substantially driven. Information on the positional relationship with the actuator 68 (synonymous with the positional relationship between the first unit and the second unit) is obtained.

The position signal correction unit 142 acquires information on the correction coefficients α and β corresponding 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. , The position signal x is corrected.

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

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

First, a position signal x output from the position detection sensor 84 is obtained (step S1). Next, information on the current zoom position is obtained from the zoom position detector 120 (step S2). Next, correction coefficients α and β corresponding to the zoom position are obtained (step S3). Next, a correction function F (x) = αx + β is set based on the obtained correction coefficients α and β to correct the position signal x (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 third lens group front group G3a is determined.

As described above, by correcting the output of the position detection sensor 84 based on the zoom position, the position of the third lens group front group G3a can always be accurately detected.

[Drive Control of Front Group of Third Lens Group]
FIG. 18 is a flowchart illustrating a procedure of a drive control process for the front group of the third lens group.

First, a target position as a destination is set (step S11). As described above, the front group G3a of the third lens group is driven by a zoom operation and a 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 front group G3a of the third lens group is obtained (Step S12). The method of acquiring the current position information 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 obtained (step S15). Then, it is determined whether or not the target position has been reached based on the obtained position information (step S16). If the target position has been 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 in steps S13 to S16 are repeated until the target position is reached.

[Modification]
In the above embodiment, the third lens group front group drive actuator 56 is constituted by the VCM, but may be constituted by another actuator.

Further, in the above-described embodiment, the fourth lens group drive actuator 68 is configured by the VCM, but may be configured by another electromagnetic actuator.

In the above embodiment, the zoom operation is performed manually, but the zoom operation may be performed electrically using a motor or the like.

Further, in the above-described embodiment, the lens group moved by zooming is driven and moved by the cam mechanism, but may be driven and moved by another driving mechanism.

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

In the above embodiment, the position of the fourth lens group G4 is detected using the photo interrupter and the MR sensor. However, the position may be detected using a 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 third lens group front group G3a.

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

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

位置 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 at a position at a regular distance D from the position detecting magnet 82.

On the other hand, if it is improperly mounted, the position detection sensor 84 is mounted in a posture inclined with respect to the optical axis Z as shown in FIG. Alternatively, it is attached to a position at a distance d different from the regular distance D from the position detecting 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.

において In the figure, a solid line W1 is a graph when the position detection sensor 84 is properly attached. A broken line W2 is a graph when the position detection sensor 84 is attached in an inappropriate posture. The dashed line W3 is a graph when the position detection sensor 84 is mounted at an inappropriate position.

When the position detection sensor 84 is mounted in an inappropriate posture (inclination posture), the inclination (sensor output sensitivity) of the graph showing the output characteristics of the position detection sensor 84 changes depending on the magnitude of the inclination (broken line W2). Graph).

Further, when the position detection sensor 84 is mounted at an inappropriate position, the intercept (sensor output bias) of the graph (see FIG. 15) indicating the output characteristics of the position detection sensor 84 changes (see the graph of the dashed-dotted line W3). .

(4) 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 influence of magnetism on the position detection sensor 84 from 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 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 checked, and a correction coefficient γ (θ) that changes according to the inclination θ is added to the correction function F (x), and F (x) = αx + (β + γ (θ)) .

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

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

The position signal correction unit 142 obtains, from the correction information storage unit 146, information on the correction coefficients α and β corresponding to the zoom position and the correction coefficients γ (θ) and δ (d) based on the mounting state, and obtains the obtained correction. A 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 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 the present embodiment, the position signal is corrected in consideration of both the mounting position (distance d from the position detecting magnet 82) of the position detection sensor 84 and the mounting posture (inclination θ with respect to the optical axis Z). However, the position signal may be corrected in consideration of 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 of the mounting position of the position detection sensor 84 The information (distance d from the position detecting magnet 82) and the information of the mounting posture (inclination θ with respect to the optical axis Z) may be stored in the correction information storage unit 146. In this case, when setting the correction function F (x), 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 vary depending on the temperature of the use environment. Therefore, in order to detect the position of the third lens group front group G3a with higher accuracy, it is preferable to consider the temperature of the use 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 use environment.

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

The correction coefficient ε (T) of the slope and the correction coefficient 切 (T) of the intercept which change depending on the temperature T are added to the correction function F (x), and F (x) = (α + ε (T)) x + (β + ζ (T)) And

The tilt 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 a position signal based on temperature.

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

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

In the present embodiment, the mounting state of the position detection sensor 84 is not considered, but 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]
[Modification of Method for Obtaining 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) of the intercept based on the temperature can be obtained by the following method.

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

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

The front group G3a of the third lens group is configured such that the first main guide part 52 and / or the first sub guide part 54 abut on one end, and thereby one movable end (one end of the movable range). ) Located. In the example shown in FIG. 23, it is located at the end on the image plane side. This position is used as a calibration reference position.

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

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

Thus, the intercept correction coefficient ζ (T) based on the temperature can be obtained from the output of the position detection sensor 84 when located at the calibration reference position. Thereby, the correction coefficient 片 (T) of the intercept based on the temperature can be acquired more appropriately.

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

[Conditions for performing temperature-based correction processing]
The correction based on the temperature 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, the correction based on the temperature is performed. Thereby, the startup time of the interchangeable lens 1 can be reduced. In particular, when the intercept correction coefficient ζ (T) is obtained by the method described in the above-described modification, the process of moving the lens to the reference position for calibration can be omitted, so that the startup time can be significantly reduced.

[Fourth Embodiment]
In the interchangeable lens 1 of the above embodiment, the actuator that drives the fourth lens group G4 (the fourth lens group drive actuator 68) is configured by a moving coil type VCM. In this case, the influence of the magnetism that the position detection sensor 84 receives from the fourth lens group drive actuator 68 is sufficient if only the change in the positional relationship between the two due to zooming is considered.

However, when the actuator that drives the fourth lens group G4 is constituted by a moving magnet type VCM, high-precision detection cannot be performed even if only the positional relationship change due to zooming is considered. This is because the moving magnet type VCM moves the magnet together with the movable part. Therefore, in order to detect the position of the third lens group front group G3a with higher accuracy, the position detection sensor 84 is considered in consideration of the position of the movable part driven by the actuator, that is, the position of the fourth lens group G4. Output (position signal) needs to be corrected.

[Structure of interchangeable lens]
First, the configuration of the interchangeable lens when the actuator that drives the fourth lens group G4 (the fourth lens group driving actuator) is configured by a moving magnet type VCM will be described. Here, only the configuration of the driving 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 configured by 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 configured by 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 constituted by the moving magnet type VCM. The fourth lens group base holding frame 26A is provided with a driving coil 66C and a plurality of outer yokes 66D constituting a moving magnet type VCM.

The driving coil 66C is wound around the outer periphery of the fourth lens group movable holding frame 26B and attached to the inner periphery 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.

Similarly to the third lens group front group drive actuator 56, the plurality of drive magnets 66A are divided into two groups, and are symmetrical with respect to a straight line L passing through the optical axis Z in a cross section orthogonal to the optical axis Z. (See FIGS. 6 and 10). The plurality of inner yokes 66B are arranged corresponding to the driving magnets 66A. Each inner yoke 66B is integrated with the corresponding driving 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 to face the corresponding inner yoke 66B with the driving 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 output of position detection sensor]
[Configuration Related to Processing for Detecting Position of Front Group of Third Lens Group Including Correction of Output of Position Detection Sensor]
FIG. 25 is a block diagram of a configuration relating to a process of detecting the position of the front group of the third lens group including the correction of the output of the position detection sensor.

As in the case of the interchangeable lens 1 of the above embodiment, the process of detecting the position of the front group G3a of the third lens group including the correction of the output of the position detection sensor 84 is performed by the lens controller 100. 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 calculator 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 calculator 148 calculates a 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 driving magnet 66A of the fourth lens group driving 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 equivalent to calculating the relative position of the position detection sensor 84 with respect to the driving magnet 66A.

The relative position calculation unit 148 acquires information on the zoom position from the zoom position detection unit 120, and acquires information on the position 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 information on the relative position calculated by the relative position calculation unit 148. Specifically, information on the relative position is obtained from the relative position calculation unit 148, and information on the correction coefficient corresponding to the obtained relative position is obtained from the correction information storage unit 146. Then, the position signal is corrected based on the obtained correction coefficient. That is, a correction function F (x) is set based on the obtained 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 stored in the correction information storage unit 146 in association with the information on the relative position.

[Procedure for detecting position of front group of third lens group including correction of output of position detection sensor]
FIG. 26 is a flowchart illustrating a procedure (a position detection method) of a process of detecting the position 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 obtained (Step S21). Next, information on the current zoom position is obtained from the zoom position detection unit 120 (step S22). Next, information on the position of the fourth lens group G4 is obtained from the fourth lens group position detecting section 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 information on the zoom position and the information on the position of the fourth lens group G4 (step S24). Next, a correction coefficient corresponding to the calculated relative position is obtained (step S25). Next, a correction function F (x) is set based on the obtained 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 third lens group front group G3a is determined.

As described above, when the actuator that drives the fourth lens group G4 is configured by 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 third lens group front group G3a can always be accurately detected.

Note that, in the present embodiment as well, correction can be applied in consideration of the mounting state and the temperature of the position detection sensor 84, thereby enabling more accurate position detection.

[Fifth Embodiment]
In the above-described embodiment, the case where the present invention is applied to the 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. 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 is also applicable 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 having a lens moving in a direction perpendicular to the optical axis and a lens moving in a direction parallel to the optical axis will be described as an example.

[Configuration of a lens barrel including a lens moving in a direction perpendicular to the optical axis and a lens moving in a direction parallel to the optical axis]
FIG. 27 is a cross-sectional view illustrating an example of a lens barrel including a lens moving in a direction perpendicular to the optical axis and a lens moving in a direction parallel to the optical axis. FIG. 28 is a sectional view taken along line 28-28 of FIG. FIG. 29 is a sectional view taken along line 29-29 of FIG.

The lens barrel 200 according to the present embodiment includes a first lens unit 220 having a lens moving in a direction perpendicular to the optical axis Z, and a second lens having a lens moving in a direction parallel to the optical axis Z. A unit 240 is provided. The distance between the first lens unit 220 and the second lens unit 240 is variable, for example, by zooming. In the present embodiment, the first lens unit 220 and the second lens unit 240 are moved by the cam mechanism, and the interval between them is variable.

In the above 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 that is 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 part of the fixed cylinder 212, and holds the inner peripheral part of the fixed cylinder 212 rotatably in the circumferential direction.

[First 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 that is a camera shake correction lens, a first lens holding frame 224 that holds the first lens 222, and a first lens 222. 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 a position of the first lens 222 in the Y-axis direction. The first lens unit 220 is an example of a first unit.

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

[First lens holding frame]
The first lens holding frame 224 includes a first lens base holding frame 224A and a first lens movable holding frame 224B. The first lens base holding frame 224A and the first lens movable holding frame 224B are integrated by sandwiching a plurality of rigid spheres 225a therebetween and connecting a plurality of locations by a spring 225b. Accordingly, the first lens movable holding frame 224B is movably supported by 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 drive cam followers 232 on the outer periphery 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 a first lens zoom drive cam groove 214A provided in the cam barrel 214 and a first lens zoom drive straight advance groove 212A provided in the fixed barrel 212, respectively. . As a result, the first lens base holding frame 224A is held in the fixed cylinder 212. Further, when the cam barrel 214 is rotated, the first lens base holding frame 224A moves along the optical axis Z in the fixed barrel 212 along a predetermined movement locus.

[First lens X-axis driving actuator and first lens Y-axis driving 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. 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, as shown in FIG. The first lens X-axis direction drive actuator 226X and the first lens Y-axis direction drive actuator 226Y are both configured by a moving coil type VCM. Therefore, a driving coil is provided in the first lens movable holding frame 224B that is a movable portion. The first lens X-axis direction drive actuator 226X and the first lens Y-axis direction drive actuator 226Y are examples of a first actuator.

[First lens X-axis direction position detection sensor and first 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 constituted by Hall sensors, and are provided by a position detection magnet provided in a first lens movable holding frame 224B that is a movable part. By detecting the position, the position of the first lens 222 in the X-axis direction and the Y-axis direction is 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 on the first lens movable holding frame 224B, and the X-axis of the first lens 222. Detect the position in the direction. 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 includes a second lens 242 serving as a focus adjusting lens, a second lens holding frame 244 holding the second lens 242, and a A pair of second lens drive actuators 246 that drive in different directions, and a second lens position detector 248 that detects the position of the second lens 242. The second lens unit 240 is an example of a second unit.

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

[Second lens holding frame]
The second lens holding frame 244 includes a second lens base holding frame 244A and a second lens movable holding frame 244B. The second lens movable holding frame 244B is disposed in the second lens base holding frame 244A, and is supported movably 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 of the second lens zoom drive cam followers 250 is fitted into a second lens zoom drive cam groove 214B provided in the cam barrel 214 and a second lens zoom drive straight groove 212B provided in the fixed barrel 212, respectively. . Thereby, the second lens base holding frame 244A is held in the fixed cylinder 212. Further, when the cam barrel 214 is rotated, the second lens base holding frame 244A moves along the optical axis Z along a predetermined movement locus inside the fixed barrel 212.

主 A main shaft 252 and a sub shaft 254 that guide the second lens movable holding frame 244B are provided in the second lens base holding frame 244A. The main axis 252 and the sub axis 254 are arranged in parallel with the optical axis Z, respectively. The second lens movable holding frame 244B includes a main guide 256 that slides along the main shaft 252 and a sub-guide 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 configured by a moving coil type VCM which is an electromagnetic actuator. Therefore, a driving coil is provided in the second lens movable holding frame 244B, which is a movable portion. The second lens drive actuator 246 is an example of a second actuator.

[Second lens position detector]
The second lens position detector 248 detects the position of the second lens 242. The second lens position detector 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 detector 248 is an example of a second optical element position detector.

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

[Operation of lens barrel]
The lens barrel 200 of the present embodiment configured as described above rotates the cam barrel 14 so that the first lens unit 220 and the second lens unit 240 move along the optical axis Z along a predetermined movement locus. 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 parallel to 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. In addition, 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 first lens X-axis direction position detection sensor and first 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 configured by a Hall sensor are provided according 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 in the following procedure.

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

Next, information on the relative positional relationship between the first lens unit 220 and the second lens unit 240 is obtained. 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 barrel 214 or the position of the first lens unit 220 or the position of the second lens unit 240 on the optical axis. Is determined. Therefore, by acquiring these pieces of information, information on the relative positional relationship between the first lens unit 220 and the second lens unit 240 is acquired.

Next, based on the obtained information on the relative positional relationship between the first lens unit 220 and the second lens unit 240, information on the correction coefficient is obtained. The information of the correction coefficient is obtained in advance for each relative position of the first lens unit 220 with respect to the second lens unit 240 and stored in the storage unit. The information of the correction coefficient 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 separately prepared.

(4) Next, a correction function is set based on the obtained correction coefficient, and the position signal is corrected. More specifically, a 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. I 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.

As described above, 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 accurately detected.

In the present embodiment, the second lens 242 is configured to move in parallel with the optical axis Z. However, the present invention is also applied to a case where the second lens 242 moves in a direction perpendicular to the optical axis Z. it can. The present invention is also applicable to a case where the first lens 222 moves parallel to the optical axis Z and the second lens 242 moves in a direction perpendicular to the optical axis Z.

Further, in the above-described 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 present invention is applied to a lens barrel integrally provided in a camera. Can be similarly applied.

The lens barrel to which the present invention can be applied is not limited to a lens barrel of a camera, but can be applied to lens barrels 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 is changed by zooming has been described as an example, but the relative positional relationship between the first unit and the second unit under other conditions. The same can be applied to the case where is changed.

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

An imaging device 300 shown in FIG. 1 is a digital camera having a so-called sensor shift type image stabilization function, and includes an imaging lens 310, an image sensor 350 that captures an optical image of a subject via the imaging lens 310, and an image sensor. A camera shake correction mechanism 360 that corrects camera shake by moving 350 in a plane perpendicular to the optical axis Z.

[Imaging lens]
The imaging lens 310 includes 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 changes continuously by moving some of the lenses along the optical axis Z. The focus is adjusted by moving some 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 imaging device 300 according to the present embodiment, the focus lens 312 moves on a predetermined movement locus by zooming, and moves independently by being driven by an actuator. The focus lens 312 is an example of a movable lens. The imaging lens 310 includes a focus lens driving unit 314 that drives the focus lens 312 and a focus lens position detection unit 316 that detects the position of the focus lens 312.

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

The focus lens 312 is held in the focus lens holding frame 318 and arranged in the imaging lens 310. The focus lens holding frame 318 includes a focus lens base holding frame 318A and a focus lens movable holding frame 318B. The focus lens movable holding frame 318B is disposed in the focus lens base holding frame 318A, and is supported movably 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.

(3) The focus lens base holding frame 318A is provided with three focus lens zoom drive cam followers 320 on its outer peripheral portion. The three focus lens zoom drive cam followers 320 are arranged at equal intervals in the circumferential direction. Each of the focus lens zoom drive cam followers 320 is fitted into a focus lens zoom drive cam groove 322A provided in the cam barrel 322 and a focus lens zoom drive straight advance groove 324A provided in the fixed barrel 324, respectively. Thus, when the cam barrel 322 is rotated, the focus lens base holding frame 318A moves along the optical axis Z along a predetermined movement locus. The cam barrel 322 is connected to a zoom ring (not shown) provided on the outer periphery of the imaging lens 310, and rotates in conjunction with the zoom ring. The set zoom position is detected by a zoom position detector (not shown).

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

The focus lens movable holding frame 318 B includes a main guide 330 that slides along the main shaft 326 and a sub guide 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 driver]
The focus lens driving unit 314 is configured by a pair of focus lens driving actuators 334. The focus lens drive actuator 334 is configured by a moving coil type VCM. Therefore, a driving coil is provided on the focus lens movable holding frame 318B which is a movable portion. The focus lens drive actuator 334 is an example of a first actuator.

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

The focus lens position detecting magnet 316A is provided on a focus lens movable holding frame 318B that is a movable part.

The focus lens position detection sensor 316B is provided in 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 to detect the position of the focus lens 312. The position here is a position in the focus lens base holding frame 318A. That is, the position is relative to the 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 constitute one unit with reference to the focus lens holding frame 318, and this unit moves in parallel with the optical axis Z by zoom operation. The unit based on the focus lens holding frame 318 is an example of a movable unit. The cam mechanism including the cam barrel 322, the fixed barrel 324, and the cam follower 320 for driving the focus lens zoom is an example of a movable unit driving unit.

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

[Image stabilization mechanism]
FIG. 32 is a sectional view taken along line 32-32 of FIG.

The camera shake correction mechanism 360 corrects the camera shake by moving the image sensor 350 in a plane perpendicular to the optical axis Z. The camera shake correction mechanism 360 detects an image sensor holding frame 362 that movably supports the image sensor 350 in a plane orthogonal to the optical axis Z, an image sensor driving unit that drives the image sensor 350, and detects the position of the image sensor 350. And an image sensor position detecting unit.

[Image sensor holding frame]
The image sensor holding frame 362 includes an image sensor movable holding frame 362A that holds the image sensor 350, an image sensor base holding frame 362B that slidably supports the image sensor movable holding frame 362A in a plane perpendicular to the optical axis Z, It consists of. In the image sensor movable holding frame 362A and the image sensor base holding frame 362B, a plurality of rigid spheres 368 are interposed therebetween, and a plurality of locations are connected by a spring 370 to be integrated. Accordingly, the image sensor movable holding frame 362A is movably supported by the image sensor base holding frame 362B in a plane orthogonal to the optical axis Z.

[Image sensor driver]
The image sensor driving 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. 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, as shown in FIG. Each of the image sensor X-axis direction drive actuator 364X and the image sensor Y-axis direction drive actuator 364Y is configured by a moving coil type VCM which is an electromagnetic actuator. Therefore, a driving coil is provided in the image sensor movable holding frame 362A which is a movable portion. The image sensor X-axis direction drive actuator 364X and the image sensor Y-axis direction drive actuator 364Y are examples of a 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 a 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 a plane orthogonal to the optical axis Z.

[Image sensor position detector]
The image sensor position detection unit includes an image sensor X-axis direction 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 Y-axis direction position of the image sensor 350. 366Y. Each of the image sensor X-axis direction position detection sensor 366X and the image sensor Y-axis direction position detection sensor 366Y is configured by a Hall sensor, and detects the position of a position detection magnet provided in the image sensor movable holding frame 362A that 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 on the image sensor movable holding frame 362A, and the position of the image sensor 350 in the X-axis direction. Is detected. The image sensor Y-axis direction position detection sensor 366Y detects the position of the Y-axis direction position detection magnet 368Y provided on 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 imaging device 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 driver includes a magnetic material, when the distance between the image sensor driver and the focus lens position detection sensor 316B changes, the output characteristics of the focus lens position detection sensor 316B change. Therefore, the output (position signal) of the focus lens position detection sensor 316B is corrected according to the zoom position. This processing is performed by the control unit of the imaging device 300. The control unit of the imaging device 300 includes a computer having a CPU, a ROM, and a RAM, and provides a function of correcting the output of the focus lens position detection sensor by executing a predetermined program.

FIG. 33 is a block diagram of a function of correcting the output of the focus lens position detection sensor provided by the control unit of the imaging device.

The control unit of the imaging device 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 obtains information on the zoom position from the zoom position detection unit 388, and obtains information on a correction coefficient corresponding to the obtained zoom position from the correction information storage unit 386. Then, a correction function is set based on the obtained 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, correction is made in advance from the output of the focus lens position detection sensor 316B for each zoom position. The coefficients α and β are determined in advance. Information on the obtained correction coefficient is stored in the correction information storage unit 386 in association with information on the zoom position. The correction information storage unit 386 is configured by, for example, a ROM.

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

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

First, a position signal output from the focus lens position detection sensor 316B is obtained (Step S31). Next, information on the current zoom position is obtained from the zoom position detector 120 (step S32). Next, a correction coefficient corresponding to the zoom position is obtained (step S33). Next, a correction function is set based on the obtained 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). Thereby, an accurate position of the focus lens 312 is obtained.

[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 by the zoom operation. Therefore, it is preferable that 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 be corrected in the same manner. Thereby, the position of the image sensor 350 can be accurately detected.

[Modification]
Also in the present embodiment, it is possible to apply a correction in consideration of the mounting state of the position detection sensor and the temperature, thereby enabling more accurate position detection.

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 be applied to the case where the movable lens moves in the direction perpendicular to the optical axis.

The application of the present invention is not limited to an imaging device as a single unit, but can be similarly applied to an imaging 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 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 and the like can be configured by various processors. For various processors, the circuit configuration can be changed after manufacturing a general-purpose processor such as CPU or FPGA (FPGA: Field Programmable Gate Array) that functions as a processing unit that executes software (programs) to perform various processes. A dedicated electrical circuit, which is a processor having a circuit configuration specifically designed to execute a specific process such as a programmable processor (PLD: Programmable Logic Device), an ASIC (Application Specific Integrated Circuit), etc. It is.

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

Also, 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 a computer such as a client or a server, one processor is configured by a combination of 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 a plurality of processing units with a single IC chip (IC: Integrated Circuit), as represented by a system-on-chip (SoC), is used. There is a form. As described above, the various processing units are configured by using one or more of the above various processors as a hardware 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 causing a computer to realize the function of correcting the output of the position detection sensor described in the above embodiment is recorded on an optical disk, a magnetic disk, or a computer readable medium that is a non-transitory information storage medium such as a semiconductor memory or other tangible material. However, it is possible to provide a program through this information storage medium. Instead of providing the program by storing the program in a non-transitory information storage medium as such a tangible entity, the program signal can be provided as a download service using an electric communication line such as the Internet.

REFERENCE SIGNS LIST 1 interchangeable lens 2 exterior body 3 focus ring 4 zoom ring 5 aperture ring 10 lens barrel main body 12 fixed barrel 12A first lens group zoom drive rectilinear groove 12B second lens group zoom drive rectilinear groove 12C third lens group zoom drive Straight groove 12D Fourth lens group zoom drive straight groove 14 Cam barrel 14A First lens group zoom drive cam groove 14B Second lens group zoom drive cam groove 14C Third lens group zoom drive cam groove 14D Fourth lens group Zoom drive cam groove 16 Mount 16A Terminal 20 First lens group holding frame 22 Second lens group holding frame 24 Third lens group holding frame 24A Third lens group base holding frame 24B Third lens group movable holding frame 26 Fourth lens Group holding frame 26A Fourth lens group base holding frame 26B Fourth lens group movable holding frame 28 Fifth lens group holding frame 30 Aperture unit 32 First lens group zoom drive cam follower 34 Second lens group zoom drive cam follower 36 Third lens group zoom drive cam follower 38 Fourth lens group zoom drive cam follower 48 First main shaft 50 First sub shaft 52 First main guide Part 52A Sliding part 54 First sub-guide part 54A Groove part 56 Third lens group front group drive actuator 56A Driving magnet 56B Inner yoke 56C Driving coil 56D Outer yoke 58 Second main shaft 60 Second sub-shaft 62 Second main guide Part 62A Sliding part 64 Second sub guide part 64A Groove 66 Fourth lens group drive actuator 66A Driving magnet 66B Inner yoke 66C Driving coil 66D Outer yoke 68 Fourth lens group driving actuator 68A Driving coil 68B Driving magnet 68C Inneryo 68D Outer yoke 70 Coil holding unit 80 Third lens group front group position detecting unit 82 Position detecting magnet 84 Position detecting sensor 90 Fourth lens group position detecting unit 92 Origin detecting unit 92A Shielding plate 92B Photointerrupter 94 Displacement amount detecting unit 94A Magnetic scale 94B MR sensor 100 Lens control section 110 Third lens group front group drive section 112 Fourth lens group drive section 114 Aperture drive section 116 Temperature detection section 118 Focus operation detection section 120 Zoom position detection section 122 Aperture setting detection section 130 Camera control section 140 Position signal acquisition section 142 Position signal correction section 144 Position calculation section 146 Correction information storage section 148 Relative position calculation section 200 Lens barrel 210 Lens barrel body 212 Fixed barrel 212A First lens zoom drive straight groove 212B Straight forward for two-lens zoom drive 212Y First lens Y-axis direction drive actuator 214 Cam barrel 214A First lens zoom drive cam groove 214B Second lens zoom drive cam groove 220 First lens unit 222 First lens 224 First lens holding frame 224A First lens base Holding frame 224B First lens movable holding frame 225a Rigid sphere 225b Spring 226X First lens X axis direction driving actuator 226Y First lens Y axis direction driving actuator 228X First lens X axis direction position detection sensor 228Y First lens Y axis direction position detection Sensor 230X Magnet for detecting position in X-axis direction 230Y Magnet for detecting position in Y-axis 232 First lens zoom drive cam follower 240 Second lens unit 242 Second lens 244 Second lens holding frame 244A Second lens base holding frame 244 Second lens movable holding frame 246 Second lens drive actuator 248 Second lens position detection unit 248A Origin detection unit 248B Displacement detection unit 250 Second lens zoom drive cam follower 252 Main shaft 254 Sub shaft 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 zoom drive Straight groove 326 Main shaft 328 Sub shaft 330 Main guide portion 332 Sub guide portion 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 axis driving Actuator 364Y Image sensor Y-axis direction drive actuator 366X Image sensor X-axis direction position detection sensor 366Y Image sensor Y-axis direction position detection sensor 368 Hard sphere 368X X-axis direction 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 locus AL2 of first lens group Second lens Trajectory AL3 of the third lens group AL4 trajectory 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 W2 when position detection sensor is properly mounted Graph W3 when position detection sensor is mounted in an inappropriate posture Position detection sensor Graph Wa when mounted at an inappropriate position Graph Wb 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 The position of the front group of the third lens group at the zoom position b Graphs S1 to S5 showing the relationship between the position of the third lens group and the output of the position detection sensor. Steps S11 to S16 Procedures S21 to S27 for drive control processing of the front lens group of the third lens group Procedures S31 to S35 for detection processing of the position of the front group of the third lens group including correction of the output of the position detection sensor Focus lens position detection sensor Of focus lens position detection processing including output correction

Claims

A first optical element movably supported in a direction parallel or perpendicular to the optical axis, a first actuator for driving the first optical element, and a magnetic field that changes according to the position of the first optical element. A first unit comprising: a position detection sensor that outputs a signal proportional to the magnitude of the detected magnetic field as a position signal;
A second unit including: a second optical element movably supported in a direction parallel or perpendicular to the optical axis; and an electromagnetic second actuator that drives the second optical element.
A unit driving unit that relatively moves the first unit and the second unit along the optical axis;
A position signal correction unit that corrects the position signal output from the position detection sensor according to a relative positional relationship between the first unit and the second unit;
The lens barrel with.
The unit drive unit relatively moves the first unit and the second unit along the optical axis according 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 a zoom position,
The lens barrel according to claim 2.
The unit drive section moves the first unit and the second unit along the optical axis by a cam mechanism.
The lens barrel according to claim 1.
The first unit and the second unit are arranged adjacent to each other;
The lens barrel according to claim 1.
The position detection sensor is a Hall sensor,
The lens barrel according to claim 1.
The second actuator is a voice coil motor,
The lens barrel according to claim 1.
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 a relative positional relationship between the first unit and the second unit and a 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 a mounting position of the position detection sensor and / or a mounting posture,
The lens barrel according to claim 1.
Further comprising 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 claim 1.
Based on the position signal output from the position detection sensor when the first optical element is positioned at the calibration reference position, obtains information necessary for correcting the position signal based on the temperature,
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.
The second unit further includes a second optical element position detector that detects a position of the second optical element.
The lens barrel according to claim 1.
The second optical element position detection unit includes:
An origin detection unit that detects movement of the second optical element to a predetermined origin,
A displacement amount detection unit that detects a displacement amount of the second optical element;
Having,
The lens barrel according to claim 13.
The displacement amount detection unit includes an MR sensor.
The lens barrel according to claim 14.
In the first unit, a lens that is the first optical element is moved in parallel with the optical axis to correct a field curvature,
In the second unit, a lens that is the second optical element is moved in parallel with the optical axis to adjust a focus.
The lens barrel according to claim 1.
A lens barrel according to any one of claims 1 to 16,
Imaging device.
A movable lens movably supported in a direction parallel 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, and a magnitude of the detected magnetic field A position detection sensor that outputs a signal proportional to the position as a position signal, and a movable unit, and a movable unit drive unit that moves the movable unit along the optical axis, and an imaging lens that includes:
An image sensor that is movably supported in a direction orthogonal to the optical axis and captures an optical image of a subject via the imaging lens;
An electromagnetic second actuator for driving the image sensor;
A position signal correction unit that corrects the position signal output from the position detection sensor according to a relative positional relationship between the movable unit and the image sensor,
An imaging device comprising:
The movable unit drive section moves the movable unit along the optical axis in accordance with a zoom operation.
The imaging device according to claim 18.
The position signal correction unit, based on a zoom position, a position signal correction unit that corrects the position signal output from the position detection sensor,
The imaging device according to claim 19.
A first optical element movably supported in a direction parallel or perpendicular to the optical axis, a first actuator for driving the first optical element, and a magnetic field that changes according to the position of the first optical element. A first unit comprising: 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 unit movably supported in a direction parallel or perpendicular to the optical axis. A second unit including an element and an electromagnetic second actuator that drives the second optical element is output from the position detection sensor in a lens barrel that relatively moves along the optical axis. A position detection method for detecting a position of the first optical element based on the position signal,
Obtaining the position signal output from the position detection sensor;
Obtaining information on a relative positional relationship between the first unit and the second unit;
Correcting the position signal output from the position detection sensor according to a relative positional relationship between the first unit and the second unit;
A position detection method including:
A movable lens movably supported in a direction parallel 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, and a magnitude of the detected magnetic field A position detection sensor that outputs a signal proportional to the position as a position signal; a movable unit driving unit that moves the movable unit along the optical axis; An image sensor that is movably supported in a direction perpendicular to the 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 a position of the movable unit based on the position signal output from the position detection sensor,
Obtaining the position signal output from the position detection sensor;
Obtaining information on the relative positional relationship between the movable unit and the image sensor;
Correcting the position signal output from the position detection sensor according to a relative positional relationship between the movable unit and the image sensor;
A position detection method including:
A first optical element movably supported in a direction parallel or perpendicular to the optical axis, a first actuator for driving the first optical element, and a magnetic field that changes according to the position of the first optical element. A first unit comprising: 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 unit movably supported in a direction parallel or perpendicular to the optical axis. A second unit including an element and an electromagnetic second actuator that drives the second optical element is output from the position detection sensor in a lens barrel that relatively moves along the optical axis. A position detection program that causes a computer to execute a process of detecting a position of the first optical element based on the position signal,
Obtaining the position signal output from the position detection sensor;
Obtaining information on a relative positional relationship between the first unit and the second unit;
Correcting the position signal output from the position detection sensor according to a relative positional relationship between the first unit and the second unit;
A position detection program that includes
A movable lens movably supported in a direction parallel 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, and a magnitude of the detected magnetic field A position detection sensor that outputs a signal proportional to the position as a position signal; a movable unit driving unit that moves the movable unit along the optical axis; An image sensor that is movably supported in a direction perpendicular to the 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. A lamb,
Obtaining the position signal output from the position detection sensor;
Obtaining information on the relative positional relationship between the movable unit and the image sensor;
Correcting the position signal output from the position detection sensor according to a relative positional relationship between the movable unit and the image sensor;
A position detection program that includes
A non-transitory and computer-readable storage medium, wherein the instructions stored in the storage medium are read by a computer,
A first optical element movably supported in a direction parallel or perpendicular to the optical axis, a first actuator for driving the first optical element, and a magnetic field that changes according to the position of the first optical element. A first unit comprising: 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 unit movably supported in a direction parallel or perpendicular to the optical axis. A second unit including an element and an electromagnetic second actuator that drives the second optical element is output from the position detection sensor in a lens barrel that relatively moves along the optical axis. A position detection function for detecting a position of the first optical element based on the position signal,
A function of acquiring the position signal output from the position detection sensor;
A function of acquiring information on a relative positional relationship between the first unit and the second unit;
A function of correcting the position signal output from the position detection sensor according to a relative positional relationship between the first unit and the second unit;
A storage medium for causing a computer to realize a position detection function including the following.
A non-transitory and computer-readable storage medium, wherein the instructions stored in the storage medium are read by a computer,
A movable lens movably supported in a direction parallel 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, and a magnitude of the detected magnetic field A position detection sensor that outputs a signal proportional to the position as a position signal; a movable unit driving unit that moves the movable unit along the optical axis; An image sensor that is movably supported in a direction perpendicular to the 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 function for detecting a position of the movable unit based on the position signal output from the position detection sensor,
A function of acquiring the position signal output from the position detection sensor;
A function of acquiring information on a relative positional relationship between the movable unit and the image sensor;
A function of correcting the position signal output from the position detection sensor according to a relative positional relationship between the movable unit and the image sensor;
A storage medium for causing a computer to realize a position detection function including the following.