JPH0821948A - Lens driving device - Google Patents

Abstract

PURPOSE:To provide a lens driving device capable of selectively moving only required lens groups so as to perform focusing in accordance with a focal distance to be set. CONSTITUTION:A zoom lens is constituted of a first lens group L1, a second lens group L2, a third lens group L3, and a fourth lens group L4. A driving mechanism driven by a zoom cam is provided on each lens group, driving shafts driven by a piezoelectric element and lens actuators 40 and 50 constituted of a member frictionally connected to the shafts are arranged on the lens group L2, and the lens groups L3 and L4 side by side. Focusing is performed by driving the lens group L2 or the lens groups L3 and L4, or both lens groups based on focal distance information and defocusing information set on the lens. Since focusing is performed by the optimum lens group in accordance with the set focal distance information, optical performance of a lens can be improved and the structure of the lens can be simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens driving device using an electro-mechanical conversion element capable of individually controlling the positions of a plurality of lens members constituting a lens.

[0002]

2. Description of the Related Art For adjusting the focus of a photographing lens such as a camera,
Whole lens feeding method for feeding the entire lens for focusing, front lens feeding method for feeding the front lens forming the taking lens for focusing, and focusing by taking out only a part of the lens group constituting the taking lens There are means such as an inner focus system. In the inner focus system, the amount of the lens group to be extended is small and the lenses can be compactly assembled. Therefore, recently, this focus adjustment system has been widely used.

In the inner focus type zoom lens, in order to correct the occurrence of aberrations due to focus adjustment, some lens groups constituting the lens are formed in accordance with the set focal length (wide angle, telephoto, etc.). There is a type that employs a focus system called a floating system in which the interval is changed.

[0004]

In such a floating type photographing lens, when the lens group to be moved is changed in accordance with the set focal length, the optical performance of the lens is improved and the recent photographing is possible. There are several advantages, such as the short contact distance. However, changing the lens group to be moved according to the set focal length is complicated and difficult to implement when using a cam mechanism that has been widely adopted for moving the lens group forming the zoom lens. It was. The present invention
It is an object of the present invention to provide a lens driving device capable of selecting and moving only a necessary lens group according to focal length information and differential focus information that are set. In the present invention, the lens group may be referred to as a lens member in order to distinguish the lens (lens assembly) including the plurality of lens groups from the plurality of lens groups.

[0005]

SUMMARY OF THE INVENTION The present invention is to solve the above problems, and comprises a plurality of lens members constituting a lens,
The electro-mechanical conversion element, a driving member coupled to the electro-mechanical conversion element and displaced together with the electro-mechanical conversion element, and a driven member fixedly coupled to the lens member and frictionally coupled to the driving member. A plurality of drive mechanisms corresponding to the plurality of lens members, and a control unit that drives the plurality of drive mechanisms based on information set in the lenses to set the plurality of lens members to predetermined positions. In the provided lens driving device, the control means selects a predetermined lens member from a plurality of lens members based on focal length information and defocus information set in the lens, drives the lens member, and sets the lens member at a predetermined position. It is characterized by

[0006]

According to the focal length information set on the lens by zoom operation and the defocus information, only the necessary lens member is selected from a plurality of lens members and driven to set it at a predetermined position. This makes it possible to obtain a lens having a simple configuration and excellent optical performance.

[0007]

Embodiments of the present invention will be described below.

[Overall Structure of Lens] FIG. 1 is a sectional view of a zoom lens to which the present invention is applied. In the figure, 1
Reference numeral 1 is an outer cylinder of the zoom lens, 12 is a mount portion for mounting the zoom lens on the camera body, and 13 is a zoom operation ring rotating on the outer cylinder 11. In this embodiment, a power zoom mechanism is adopted. Therefore, it is an operation ring for inputting the drive amount of the zoom mechanism. Further, 14 is a retaining ring of the zoom operation ring 13.

A fixed inner cylinder 21 fixed to the outer cylinder 11 is arranged inside the outer cylinder 11, and a zoom cam ring 22 is fitted on the outer side of the fixed inner cylinder 21. The protrusion 22m formed on the inner surface of the zoom cam ring 22 in the circumferential direction is fixed to the inner cylinder 21.
Is engaged with the groove 21m formed in the zoom cam ring 2
Reference numeral 2 does not move in the optical axis direction, but is rotatably supported. Further, the zoom cam ring 22 is connected to the zoom motor 25 through a driving mechanism including a driving gear 23 and a pinion 24 provided at one end thereof, and is rotationally driven by the zoom motor 25.

The zoom lens includes a first lens unit L1, a second lens unit L2, a third lens unit L3, and a fourth lens unit L4.
Consists of The first lens group L1 is in the first lens group holding frame 31, and the second lens group L2 is in the second lens group holding frame 32.
The third lens group L3 is held by the third lens group holding frame 33, and the fourth lens group L4 is held by the fourth lens group holding frame 34.

A straight groove 11a having a bottom is formed on the inner surface of the outer cylinder 11 for restricting the rotation of the first lens group holding frame 31.
In the first lens group holding frame 31, a pin 31p that engages with the rectilinear groove 11a is planted. On the other hand, a cam groove 22a is formed in the zoom cam ring 22 that is rotatably fitted into the fixed inner cylinder 21, and a pin that engages with the cam groove 22a is formed in the first lens group holding frame 31. 31q is planted. With this configuration, when the zoom cam ring 22 rotates, the first lens group holding frame 31 moves to the cam groove 22 of the zoom cam ring 22.
It moves in the optical axis direction along a.

The straight groove 11a on the inner surface of the outer cylinder 11, the cam groove 22a of the zoom cam ring 22, and the pins 31p and 31q of the first lens group holding frame 31 are formed at three locations in the circumferential direction. . As a result, the first lens group holding frame 31 is set at an accurate position with respect to the outer cylinder 11.

The lens actuator 40 is a fixed inner cylinder 2
It is held inside 1 so as to be movable in the optical axis direction. The fixed inner cylinder 21 is formed with a rectilinear groove 21b for restricting the rotation of the lens actuator 40. On the other hand, the zoom cam ring 22 rotatably fitted on the outer side of the fixed inner cylinder 21 has a cam. The groove 22b is formed. Since the pin 40p planted in the lens actuator 40 penetrates the intersection of the straight groove 21b and the cam groove 22b, when the zoom cam ring 22 rotates, the lens actuator 40 will be in the cam groove. It moves along the optical axis 22b. A second lens group holding frame 32 is supported on the lens actuator 40 so as to be movable in the optical axis direction. The details of the configuration will be described later.

The lens actuator 50 is a fixed inner cylinder 21.
It is movably held inside the optical axis. A cam groove 21c is formed in the fixed inner cylinder 21, while a straight groove 22c is formed in a zoom cam ring 22 which is rotatably fitted to the outer side of the fixed inner cylinder 21. The pin 50p planted in the lens actuator 50 penetrates the intersection of the straight groove 22c and the cam groove 21c. Therefore, when the zoom cam ring 22 rotates, the lens actuator 50 is fixed. It moves in the optical axis direction while rotating along the cam groove 21c of the inner cylinder 21. Lens actuator 50
The third lens group holding frame 33 is movably supported in the optical axis direction. The details of the configuration will be described later.

A zoom cam ring 61 for the fourth lens group is fitted on the outside of the third lens group holding frame 33.
Protrusion 6 formed in the circumferential direction on the inner surface of zoom cam ring 61
1 m is a groove 3 formed on the outer surface of the third lens group holding frame 33.
Since it is engaged with 3 m, the zoom cam ring 61 is rotatably supported with respect to the third lens group holding frame 33 without moving in the optical axis direction.

The fixed inner cylinder 21 is formed with a rectilinear groove 21d for restricting the rotation of the zoom cam ring 61, and the zoom cam ring 61 has a pin 61p which engages with the rectilinear groove 21d of the fixed inner cylinder 21. Are planted. When the lens actuator 50 moves in the optical axis direction while rotating along the cam groove 21c of the fixed inner cylinder 21, the third lens group holding frame 33 also moves in the optical axis direction while rotating. Therefore, the zoom cam ring 61, which is rotatably supported by the third lens group holding frame 33, also moves in the optical axis direction, but at this time, the pin 61p is engaged with the rectilinear groove 21d of the fixed inner cylinder 21. Therefore, the rotation of the zoom cam ring 61 is restricted.

On the other hand, the fourth lens group holding frame 34 is disposed inside the third lens group holding frame 33, and the third lens group holding frame 33 has a straight line for restricting rotation of the fourth lens group holding frame 34. The groove 34b is formed. A cam groove 61c is formed in the zoom cam ring 61 fitted to the outside of the third lens group holding frame 33, and the pin 61q planted in the fourth lens group holding frame 34 is a straight groove 34b. And cam groove 6
Since it penetrates the intersection with 1c, when the third lens group holding frame 33 moves in the optical axis direction while rotating, the fourth lens group holding frame 34 moves along the cam groove 61c of the zoom cam ring 61. , Relative to the third lens group holding frame 33 in the optical axis direction.

When the lens is set to the wide-angle side, the first lens unit L1 and the second lens unit L2 come close to each other because the first lens unit L1 and the second lens unit L2 come close to each other. It cannot be said that there is no risk of collision. Therefore, the second lens group holding frame 32 facing the first lens group L1
A buffer member 32k made of an elastic material is provided on the.

[Structure of Lens Actuator] The lens actuator 40 and the lens actuator 50 have substantially the same structure. First, the lens actuator 40
Will be described.

FIG. 2 is a perspective view in which a part of the structure of the lens actuator 40 for moving the first lens unit L1 is cut away. Referring to FIGS. 1 and 2, the lens actuator 4
The configuration of 0 will be described. In the support frame 41 of the lens actuator 40, a drive shaft 42 that drives the second lens group holding frame 32 in the optical axis direction is provided with a drive shaft 42 by a receiver 41a at the front end of the support frame 41 and a receiver 41b at the middle part. It is supported so that it can move in any direction. A piezoelectric element 43 is fixed to one end of the drive shaft 42, and the other end of the piezoelectric element 43 is attached to the flange 4 of the support frame 41.
It is fixed to 1c. Further, the support frame 41 is provided with a guide groove 41d that allows the first lens group holding frame 32 to move in the optical axis direction but prohibits rotation.

The second lens group holding frame 32 is provided with a fitting portion 32a penetrating the drive shaft 42, and the fitting portion 32a.
The drive shaft 42 and the drive shaft 42 are pressed against each other by a pressing spring 32b and are frictionally coupled to each other by an appropriate friction force. FIG. 3 is a view showing a cross section near the fitting portion 32 a, showing the fitting portion 3 of the second lens group holding frame 32.
2a and the drive shaft 42 are in pressure contact with each other by the pressure contact spring 32b. A projection 32c is formed on the second lens group holding frame 32 and is engaged with a guide groove 41d formed on the support frame 41.

In the above structure, when a drive pulse having a waveform consisting of a gentle rising portion and a rapid falling portion following it as shown in FIG. 4 is applied to the piezoelectric element 43,
At the gently rising portion of the drive pulse, the piezoelectric element 43
Causes a gradual elongation displacement in the thickness direction, and the drive shaft 42 moves in the axial direction in the direction of arrow a. Therefore, the second lens group holding frame 32, which is pressed against the drive shaft 42 by the pressing spring 32b and frictionally coupled, also moves in the direction of arrow a, so that the second lens group L2 can be moved in direction of arrow a. .

At the rapid trailing edge of the drive pulse, the piezoelectric element 43 rapidly contracts in the thickness direction. At this time, the second lens group holding frame 32 that is in pressure contact with the drive shaft 42 by the pressure contact spring 32b causes the drive shaft 4 to move due to its inertial force.
The first lens unit L1 does not move because it overcomes the frictional force with 2a and stays substantially at that position.

The term "substantially" as used herein means that the first lens group holding frame 32 and the drive shaft 42 follow each other while slipping in both the arrow a direction and the opposite direction.
It is meant to include those that move in the direction of arrow a as a whole due to the difference in driving time. The form of movement is determined according to the given friction conditions.

By continuously applying the drive pulse having the above waveform to the piezoelectric element 43, the second lens unit L2 is moved to the arrow a.
It can be moved continuously in the direction indicated by.

The movement of the second lens unit L2 in the direction opposite to the arrow a can be achieved by applying to the piezoelectric element 43 a drive pulse having a waveform having a rapid rising portion and a gentle falling portion following the rising portion. .

The structure of the lens actuator 50 for moving the third lens unit L3 is the same as the structure of the lens actuator 40. Support frame 51 for lens actuator 50
A drive shaft 52 that drives the third lens group holding frame 33 in the optical axis direction is supported by a receiver 51 a at the tip end of the support frame 51 and a receiver 51 b at the intermediate portion so as to be movable in the optical axis direction. The piezoelectric element 53 is fixed to one end of the drive shaft 52, and the other end of the piezoelectric element 53 is fixed to the flange 51c of the support frame 51. In addition, the support frame 51 is provided with a guide groove 51d that allows the first lens group holding frame 33 to move in the optical axis direction but prohibits rotation.

The third lens group holding frame 33 is provided with a fitting portion 33a penetrating the drive shaft 52, and the fitting portion 33a.
The drive shaft 52 and the drive shaft 52 are pressed against each other by a pressure contact spring (not shown) and are frictionally coupled to each other with an appropriate friction force. Further, the third lens group holding frame 33 is formed with a protrusion 33 c, and the supporting frame 51
It engages with the guide groove 51d formed in the.

In the above structure, by applying a drive pulse having a waveform having a gentle rising portion and a rapid falling portion subsequent thereto as shown in FIG. 4 to the piezoelectric element 53, the third lens unit L3 and the fourth lens unit L3 The lens unit L4 can be moved to the right in FIG. 1, and by applying a drive pulse having a waveform having a rapid rising portion and a gentle falling portion following the rising portion to the piezoelectric element 53, the third lens unit L3 As with the lens actuator 40, the fourth lens unit L4 can be moved leftward in FIG.

[Control of Zoom Lens] The control of the zoom lens will be described. FIG. 5 is a block diagram of the zoom lens control circuit. In FIG. 5, 100 is a control circuit on the lens side, and 200 is a control circuit on the camera side. The lens side control circuit 100 includes a CPU 101, a lens position sensor 102 for detecting the position of a first lens group connected to an input port of the CPU 101, a lens position sensor 103 for detecting the position of a second lens group, and a lens position sensor 103 for detecting the position of the second lens group. A lens position sensor 104 for detecting the positions of the third and fourth lens groups, and a zoom operation ring 13
Zoom operation ring encoder 105, C for detecting the rotation angle of
A zoom motor drive circuit 106 connected to the output port of the PU 101, a drive circuit 107 for driving the first lens actuator 40, and a drive circuit 108 for driving the second lens actuator 50. Composed of. The control circuit 200 on the camera side is provided with the AF sensor 20 necessary for describing the embodiment.
1, only the power source 202 is shown.

Although not shown in the drawings, the structure of the encoder and the sensor, the arrangement in the lens, and the like, known encoders and sensors can be used, and the arrangement can be appropriately arranged by those skilled in the art. Is.

[Lens Control Operation] FIG. 6 shows the focal length set for the lens and the first lens unit L1 and the second lens unit L2.
, Which is a diagram for explaining the positions of the third lens unit L3 and the fourth lens unit L4, showing the movement loci of the respective lens units that move in accordance with the set focal length. In FIG. 6, the movement locus shown by the solid line is the movement locus by the zoom cam, and shows the state of the focus infinity position, and the movement locus shown by the dotted line is the movement locus by the lens actuator, which is the latest focus. The state of the contact position is shown.

As is apparent from FIG. 6, in the present invention,
The focal length set on the lens is the wide-angle end W and the focal length fA.
In the range (this range is called the rear focus zone), only the third lens unit L3 and the fourth lens unit L4 are moved to match the subject between the infinity position and the closest position. To burn. When the focal length set for the lens is between the telephoto end T and the focal length fB (this range is called the internal focus zone), the second lens unit L2 alone is moved. Focus on the subject between the infinity position and the closest position.

Further, the focal length set on the lens is f
When it is between A and fB (this range is called the internal rear focus zone), the second lens unit L2,
Both the third lens unit L3 and the fourth lens unit L4 are moved to focus on an object between the infinity position and the closest position. In this zone, the ratio of the extended amounts of the second lens unit L2, the third lens unit L3, and the fourth lens unit L4 changes according to the set focal length. Therefore, the amount of extension according to the focal length is calculated in advance and stored in a storage device such as a ROM. Instead of calculating the extension amount according to the focal length and storing it in a storage device such as a ROM, it may be calculated as a function of the focal length.

In this zone, the second lens unit L2,
The reason why both the third lens unit L3 and the fourth lens unit L4 are moved to bring them into focus is to smoothly switch the movement of the lens units before and after the zone switching point. If there is no internal rear focus zone in the middle zone, for example, when zooming from the wide-angle end W to the telephoto end T, the third lens is provided before and after the switching point of the focal length fA. The group L3 and the fourth lens group L4 are instantaneously moved from the feeding position to the infinity position, and the second lens group L
This is because 2 has the inconvenience of having to move from the infinity position to the feeding position in an instant.

The focusing operation of the lens will be described. Figure 7 is CP
Flow chart explaining the focusing operation executed in U101.
It is From the lens position of the first lens group which is constantly detected by the lens position sensor 102, the focal length f1 currently set for the lens is detected (step P1), and the set focal length f1 becomes the wide-angle end W shown in FIG. It is judged whether or not it is within the focal length fA (f1≤fA) (step P
2).

When the set focal length f1 has a relation of f1≤fA, it is judged that f1 is in the rear focus zone,
The distance measurement data (defocus amount) detected by the AF sensor 201 on the camera side is read (step P3), and the distance measurement data is read.
Calculating the drive amount required to move the third lens unit L3 and the fourth lens unit L4 from the controller (step P4), and supplying the required number of drive pulses to the lens actuator 50 via the drive circuit 108. The third lens unit L3 and the fourth lens unit L4 are driven (step P5). The in-focus state is determined (step P6), and when not in focus, the process returns to step P3 to continue the in-focus operation, and when in-focus, the third lens unit L3
And the driving of the fourth lens unit L4 is stopped (step P
7), the process ends.

If the set focal length f1 is not in the relation of f1≤fA in the judgment of step P2, whether the set focal length f1 is between the focal length fB and the telephoto end T shown in FIG. 6 (f1≥ fB) is determined (step P11).

When the set focal length f1 has a relation of f1≥fB, it is determined that f1 is in the internal focus zone, and the distance measurement data (deflocus) detected by the AF sensor 201 on the camera side is detected. Read amount (step P1)
2) Calculate the drive amount required to move the second lens unit L2 from the distance measurement data (step P13), and drive circuit 1
After passing 07, a required number of drive pulses are supplied to the lens actuator 40 to drive the second lens unit L2 (step P14). The in-focus state is determined (step P15), and when not in focus, the process returns to step P12 to continue the in-focus operation,
When focused, the driving of the second lens unit L2 is stopped.

The set focal length f1 is determined in step P11.
Is not in the relation of f1 .gtoreq.fB, the set focal length f1 is the internal focal length between the focal lengths fA and fB shown in FIG.
It is determined that there is a rear focus zone, and the distance measurement data (defocus amount) detected by the AF sensor 201 on the camera side is read (step P21), and the second lens group L2, The drive amount required to move the third lens unit L3 and the fourth lens unit L4 is read from a storage device such as a ROM (step P22), and the drive circuits 107 and 108 are read.
Then, a required number of drive pulses are supplied to the lens actuators 40 and 50 to move the second lens unit L2, the third lens unit L3 and the fourth lens unit L4 (step P2).
3). The in-focus state is determined (step P24), and when not in focus, the process returns to step P21 to continue the in-focus operation, and when in-focus, the second lens group L2, the third lens group L3 and the fourth lens group L4 Stop driving.

Further, when the focal length set on the lens is at the switching point between the focus zones shown by fA and fB in FIG. 6, it is judged as the rear focus zone or the internal focus zone. Then, the lens actuator 50
Alternatively, if only the lens actuator 40 is driven, the lens can be easily driven.

Next, the zooming operation of the lens will be described. The lens of this embodiment is a variable focal length optical system lens,
When the lens is not at infinity, the second
Lens group L2, third lens group L3, and fourth lens group L4
Focusing is performed by extending and retracting. The amount of extension of each lens group (hereinafter referred to as the focus correction amount) may be calculated in advance in accordance with the focal length and stored in a storage device such as a ROM. You may ask.

FIG. 8 is a flow chart for explaining the zoom operation executed by the CPU 101. First, the lens is focused on an object at a certain finite distance, and the focal length f1 set on the lens at that time is on the wide-angle side (f1≤fA) with respect to the focal length fA, and the third lens unit L3 and the third lens unit L3 It is assumed that the fourth lens unit L4 is extended to the film surface side by a distance d1. Therefore, set focal length f1
Will be in the rear hood.

The direction of the rotational operation of the zoom operation ring 13 operated by the photographer is determined (step P31), and when it is determined that the zooming direction is from the wide angle side to the telephoto side, the direction of the rotational operation is determined. And a driving signal is output to the driving circuit 106 based on the speed (zooming speed) to start driving the zoom motor 25. The focal length f1 at that time and the zooming speed are detected (step P32), and the target focal length f
2 is calculated (step P33).

It is judged whether or not the focal length f1 is less than or equal to the focal length fA which is the boundary value of the rear focus (f1 <fA) (step P34). When the focal length f1 <fA, the target focal length f2 is determined. Is equal to or less than the focal length fA which is the boundary value of the rear focus zone (f2 ≤ fA)
It is determined whether or not (step P35). Step P35
If f2 ≤ fA is not satisfied in the judgment of, the target focal length f2 is set to f.
Set to 2 = fA (step P36).

The focus correction amount for focusing is read from the storage device or calculated (step P3).
7), lens actuator 5 via drive circuit 108
The required number of drive pulses is supplied to 0 to drive the third lens unit L3 and the fourth lens unit L4 (step P38).

It is determined whether or not the zoom operation ring 13 is being operated (step P39). If the zoom operation ring 13 is being operated, the operation returns to step P31 to continue the zoom operation. If not, the zoom operation is performed. The process is stopped (step P40), and the process ends.

At step P34, the focal length f1 <f
When it is not A, the target focal length f1 is equal to or less than the focal length fB which is the boundary value of the internal focus zone (f1 <
fB) or less (step P41), and if the focal length f1 <fB, the target focal length f2 is the rear focus.
It is determined whether or not the focal length fB which is the boundary value of the cascade is less than or equal to (f2 .ltoreq.fB) (step P4).
2). If f2 .ltoreq.fB is not determined in step P42, the target focal length f2 is set to f2 = fB (step P43).

The focus correction amount for focusing is read out from the storage device or calculated (step P4).
4), the movement ratio of the lens actuators 40, 50 is determined (step P45), and a required number of drive pulses are supplied to the lens actuators 40, 50 via the drive circuits 107, 108 to generate a second pulse. The lens unit L2, the third lens unit L3 and the fourth lens unit L4 are driven (step P46).

Move to step P39, and zoom operation ring 13
Is being operated, and if it is being operated, step P3
Returning to 1, the zoom operation is continued, and if it is not being operated, the zoom operation is stopped (step P40), and the processing is ended.

At step P41, the focal length f1 <f
If it is not B, it is the internal focus zone by the second lens unit L2, so the focus correction amount for focusing is read from the storage device or calculated (step P51), and the drive circuit 108 is set. A required number of drive pulses are supplied to the lens actuator 40 via the lens actuator 40 to drive the second lens unit L2 (step P52). It is determined whether or not the lens actuator 40 has reached the end of the zoom range (step P53), and when it reaches the end of the zoom range, the zoom operation is stopped (step P40). , The process ends. If the end of the zoom range has not been reached, the process moves to step P39 to determine whether the zoom operation ring 13 is being operated. If it is, the process returns to step P31 to continue the zoom operation. If the operation is not being performed, the zoom operation is stopped (step P40), and the processing is ended.

Even when it is determined in step P31 that the zooming direction is from the telephoto side to the wide-angle side,
The process is performed by determining which focus zone the set focal length is in, but the description is omitted because it is a process similar to the above process.

[0053]

As described above, according to the present invention, a driving mechanism using an electro-mechanical conversion element is provided for each of a plurality of lens members constituting a lens, and focal length information set on the lens and a default value are set. -A predetermined lens member is selected from a plurality of lens members based on the dust information and driven to set at a predetermined position, so that the focus adjustment can be performed by the optimum lens member according to the set focal length. The optical performance of the lens can be improved. Further, since the complicated cam mechanism is not used, the lens structure can be simply summarized.

[Brief description of drawings]

FIG. 1 is a sectional view showing the configuration of a zoom lens to which the present invention is applied.

FIG. 2 is a partially cutaway perspective view showing the configuration of a lens actuator.

FIG. 3 is a cross-sectional view showing a frictional contact state between a drive shaft of a lens actuator and a contact member.

FIG. 4 is a diagram showing a waveform of a drive pulse applied to a lens actuator.

FIG. 5 is a block diagram of a zoom lens control circuit.

FIG. 6 is a diagram illustrating a movement trajectory of a lens member that constitutes a zoom lens.

FIG. 7 is a flowchart for explaining a focusing operation executed by a zoom lens control circuit.

FIG. 8 is a flowchart for explaining a zoom operation executed by a zoom lens control circuit.

[Explanation of symbols]

 11 Zoom Lens Outer Cylinder 12 Mount Part 13 Zoom Operating Ring 21 Fixed Inner Cylinder 22 Zoom Cam Ring 40 Lens Actuator 50 Lens Actuator 31 First Lens Group Holding Frame 32 Second Lens Group Holding Frame 33 3rd lens group holding frame 34 4th lens group holding frame 61 Zoom cam ring L1 1st lens group L2 2nd lens group L3 3rd lens group L4 4th lens group

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location G03B 3/10 13/34 (72) Inventor Junji Hashimura 2-3-3 Azuchi-cho, Chuo-ku, Osaka-shi, Osaka Osaka International Building Minolta Camera Co., Ltd.

Claims (1)

[Claims] 1. A plurality of lens members constituting a lens, an electro-mechanical conversion element, a driving member coupled to the electro-mechanical conversion element and displaced together with the electro-mechanical conversion element, and fixedly coupled to the lens member. And a plurality of driving mechanisms corresponding to a plurality of lens members configured by a driven member frictionally coupled to the driving member, and driving the plurality of driving mechanisms based on the information set in the lens. And a control means for setting each of the lens members to a predetermined position, the control means selects a plurality of lens members from a plurality of lens members based on focal length information and defocus information set on the lens. A lens driving device, characterized in that the lens member is selected and driven to be set at a predetermined position.