JPH06118293A - Lens barrel - Google Patents

Abstract

PURPOSE:To provide three modes: 'full-time manual', 'acceleration manual', and 'manual lock', in a lens barrel using a ultrasonic motor for an AF motor and capable of switching to the manual action without using a special switching means. CONSTITUTION:A manual action ring 4 is made slidable at three positions in the optical axis direction, and 'full-time manual' is realized by the coupling with a manual action input ring 17 at the middle position. When the manual action ring 4 is slid backward, 'acceleration manual' is realized by the coupling with a ring 20 serving as an output member. When the manual action ring 4 is slid forward, 'manual lock' is realized by the coupling with a friction washer 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel incorporating an annular ultrasonic motor, and more particularly to a focusing lens constructed so that an autofocus operation and a manual focus operation can be performed almost continuously. The present invention relates to a lens barrel with a built-in motor.

[0002]

2. Description of the Related Art Conventionally, a lens barrel having a built-in focus motor, which is configured to perform an autofocus operation and a manual focus operation almost continuously without requiring special switching, has been disclosed in Japanese Patent Application Laid-Open No. HEI 2 (1993) -1998. No. 253,214.

The structure of this switching mechanism will be briefly described. The fact that the rotor of the ultrasonic motor is in pressure contact with the stator when the ultrasonic motor is not driven and is held by a large frictional force is utilized. The switching mechanism using the mechanism switches between the output of the ultrasonic motor and the output from the manual operation ring without requiring a special operation, so that auto focus and manual focus can be performed.

[0004]

However, in the above-mentioned conventional example, only the operation without switching between the auto focus operation and the manual focus operation can be performed mechanically, and moreover the rotation angle of the manual operation ring and the rotor rotation of the ultrasonic motor. The horn is always involved in the movement of the focus group in the same way. That is, 1 manual operation ring
When it is rotated, the roller carrying member rotates 1/2 turn to move the focus group, and at the time of autofocus, even when the rotation of the rotor by the ultrasonic motor is one rotation,
The roller carrying member is rotated by 1/2 to move the focus group.

When actually trying to perform a manual focus, or when the entire rotation angle of the manual operation ring is large, the manual operation ring must be rotated, and the operation ring must be changed and further rotated. I couldn't perform a special manual focus operation and missed a shooting opportunity.

An object of the present invention is to provide a lens barrel that solves the above-mentioned conventional problems.

[0007]

A lens barrel for achieving the object of the present invention is, for example, a lens barrel having a ring-shaped ultrasonic motor built therein, and a specific configuration thereof is a rotor of the motor. Is equipped with a bearing / output member that is driven to rotate by the rotor when driven, and that is driven to rotate by a manually operated input ring that interlocks with the manually operated ring when the manually operated ring is rotated. Further, a switching means for disconnecting the interlocking between the manual operation ring and the manual operation input ring and interlocking the manual operation ring with the bearing / output member is provided.

That is, in the lens barrel of the present invention,
When the manual operation ring is rotated, the bearing / output member is rotationally driven by the rotational force of the fingers of the camera user, but in other cases, the bearing / output member is rotationally driven by the vibration wave motor. Therefore, the mode that determines whether or not the manual focus operation is performed depends only on whether or not the camera user operates the manual operation ring. At least 2 with a mode that can obtain different settings of the focus movement amount during rotation
The photographer can select one of the two modes by using a switching means. Furthermore, after autofocus, a mode is also possible in which manual focus is locked so that the manual ring is inadvertently applied with force and the focus does not shift.

[0009]

FIG. 1 showing an embodiment embodying the above-described structure.
The operation will be described with reference to FIG. 5, when the user of the lens barrel tries to drive the lens holder 5 by the force of the vibration wave motor 26, a focusing switch (not shown) is operated. Then, a voltage is applied to the electrostrictive element 7 by the operation of a control circuit (not shown), and as a result, a vibration that travels in the circumferential direction is generated in the vibrating member 6, and the vibration of the vibrating member 6 causes the rotating cylinder 13 and the rubber ring to rotate. A rotor composed of 14 and the circumferential moving member 15 is rotated about the optical axis Z. Due to the rotation of the rotor, the hollow roller 18 receives the rotation torque from the rotary cylinder 13, but at this time, the manual operation ring 4
Since the ring 17 has not been rotated, the roller 18 also rotates along the end face of the ring 17 while rotating around the roller support shaft 19,
The ring 20 has an optical axis Z through a roller support shaft 19.
Is rotated around. Therefore, the lens holder driving arm 22 is also rotated around the optical axis Z together with the ring 20, so that the lens holder 5 is rotated around the optical axis Z and is axially moved to perform focusing by driving the motor. .

On the other hand, when the lens barrel user wants to drive the lens holder 5 with the force of the vibration wave motor 26 without using the force of the vibration wave motor 26, the manual operation ring 4 is operated without operating the focusing switch. It is rotated with a finger about the optical axis Z. Then, the ring 17 overcomes the frictional resistance with the friction washer 21 and rotates about the optical axis Z. However, at this time, since the vibration wave motor 26 is not driven, the rotary cylinder 13 which is the rotor of the motor is stationary. Therefore, the roller 18 rolls along the end surface of the rotary cylinder 13 while being rotated by the ring 17. As a result, the ring 20 is rotated about the optical axis Z via the roller support shaft 19, and the lens holder 5
Is rotated by the drive arm 22 and axially moves to perform focusing by manual drive.

In the above, the rotation ratio between the rotary cylinder 13 and the ring 20, and the manual operation input ring 17 and the ring 2 are used.
The rotation ratios to 0 are 2: 1 respectively. With the above structure, when the manual operation ring 4 is rotated with a finger around the optical axis Z by the connecting means for connecting the manual operation ring 4 and the ring 20 in the rotation direction, the ring 20 is also directly moved around the optical axis Z. It is rotated, and at this time the vibration wave motor 2
Since 6 is not driven, the rotary cylinder 13, which is the rotor of the motor, is stationary, so the roller 18 moves along the end surface of the rotary cylinder 13 while being rotated by the ring 20. As a result, the lens holder 5 is axially moved while being rotated by the drive arm 22, and focusing by manual drive can be performed. At this time, the rotation ratio of the manually operated ring 4 and the ring 20 is 1: 1 and the coarse focusing is realized.

As the switching means, the manual operation ring 4 is moved in the optical axis direction to disengage the manual operation ring 4 from the manual operation input ring 17, and the manual operation ring 4 and the ring are newly added. It can be realized by engaging with 20.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the lens barrel according to the present invention will be described in detail below with reference to the drawings. 1 to 3 are longitudinal cross-sectional views of an essential part of an embodiment of a lens barrel according to the present invention, showing respective states in a switching mode, and FIG. 4 is a developed view of an upper portion of FIG.

Reference numeral 1 denotes an outer cylinder of the lens barrel, 3 denotes an outer cylinder arranged in front of the outer cylinder, and an inner diameter portion thereof is fitted with a lens holder 5,
Fixed barrel 5 having a cam groove 3a for focusing
Reference numeral 5a denotes a lens holder having an outer diameter portion fitted to the inner peripheral portion of the fixed barrel 3 and fixing the focus lens group L on the inner peripheral side.
At least three focus loops 28 are fixed in the radial direction with respect to the optical axis, and are positioned by engaging with the cam groove 3a. 4 is a circumferential groove formed on the outer peripheral surface of the outer cylinder 1,
A manual that is fitted by a circumferential groove formed on the outer peripheral surface of the tubular body 2 and is supported so as to be rotatable about the central axis Z (that is, the optical axis) of the lens L and movable in the optical axis direction. It is an operation ring.

A cylindrical drive generating unit 25 is inserted in an annular space between the outer cylinder 1 and the fixed cylinder 3, and is fixed to the outer cylinder 1 and the fixed cylinder 3 with screws at a portion 2a. .

The vibration wave motor 2 is provided on the outer peripheral surface of the cylindrical body 2.
6 are mounted, a motor bearing and output member 27 that contacts the rotor portion of the vibration wave motor 26, and a manually operated input ring 17 for inputting the rotational torque of the manually operated ring 4. The components of the vibration wave motor 26, the structure of the motor bearing / output member 27, and the like will be described below.

The vibration wave motor 26 has an annular vibrating member 6 having a trapezoidal cross section, an electrostrictive element 7 physically bonded to one end surface of the vibrating member 6, and a surface of the electrostrictive element 7. A ring-shaped vibration absorber 10 made of felt or the like that is pressed into contact, a ring-shaped spacer 9 arranged in contact with one end surface of the vibration absorber 10, and a ring-shaped disc spring 8 that pushes the spacer 9 toward the ring-shaped vibration member. , A threaded portion 2b formed on the outer peripheral surface of the tubular body 2.
An annular nut 12 that is screwed into a ring, an annular washer (not shown) interposed between the nut 12 and the disc spring 8, a rotary cylinder 13 that is a part of the rotor of the vibration wave motor 26, In order to prevent axial vibration from being transmitted to the rotary cylinder 13, the rubber ring 14,
It is constituted by various members such as a ring-shaped circumferential moving member 15, a vibration member rotation stopping member 16 which is fitted to the tubular body 2 and whose outer peripheral edge projection 16a is inserted into the groove 6a of the vibration member 6. Has been done.

The rotary cylinder 13, the rubber ring 14, and the circumferential moving member 15 are integrated to form a rotor of the motor 26, and the rotary cylinder 13 and the rubber are vibrated by the circumferential traveling wave vibration generated in the vibrating member 6. A rotor including the ring 14 and the circumferential movement member 15 rotates about the optical axis Z.

The nut 12 is a member for adjusting the contact pressure between the vibrating member 6 and the circumferential moving member 15 by adjusting the elastic force of the disc spring 8, and the roller 18 and the manual operating force described later. It also serves as means for adjusting the contact pressure between the input ring 17 and the rotary cylinder 13.

The motor bearing / output member 27 disposed adjacent to the end surface of the rotary cylinder 13 (ie, rotor) of the vibration wave motor 26 is a ring 20 fitted to the outer peripheral surface of the cylindrical body 2 so as to be rotatable only. And a roller support fixed so as to project from the outer peripheral surface of the ring 20 at least at three locations on the circumference of the ring 20 on a radial axis orthogonal to the axis Z of the ring 20 (axis of the vibration wave motor). Axis 19,
The roller support shaft 19 is rotatably fitted into the hollow stepped roller 18.

The ring 20 also serves as an output member of the driving force generating unit 25, and the L-shaped lens holder driving arm 22 for rotationally driving the lens holder 5 has a screw 2.
It is adapted to be fastened to the end face of the ring 20 by means of 4.

The roller 18 has a head flange that engages with the outer peripheral surface of the rotary cylinder 13 and the outer peripheral surface of the ring 17. The roller 18 prevents rattling of the rotary cylinder 13 and the ring 17 in the radial direction during rotation by the head flange, and contacts the end surface of the rotary cylinder 13 and the end surface of the ring 17 on the outer peripheral surface. is doing.
The mutual contact pressure between the roller 18 and the end face of the rotary cylinder 13 is determined by the annular disc spring 8 and the annular nut 12 which are components of the vibration wave motor 26.

The manual operation input ring 17 is the cylindrical body 2.
The ring 17 is rotatably fitted to the outer peripheral surface of the roller 18 at one end surface (the end surface on the right side in FIG. 1) and the friction washer 21 at the other end surface. Further, the ring 17 has an uneven portion which engages with the uneven portion of the inner peripheral surface of the manual operation ring 4, and the ring 17 is rotated by the manual operation ring 4. The friction washer 21 is integrally fixed to the cylindrical body 2. The friction washer has an uneven portion on the outer peripheral portion similar to the manual operation input ring, and the uneven portion on the inner peripheral surface of the manual operation ring 4 is provided. Can be engaged with. The manual operation input ring 17 can rotate only when a drive torque larger than the frictional resistance between the friction washer 21 and the ring 17 is transmitted from the manual operation ring 4, and does not rotate otherwise.

The outer peripheral surface of the ring 20 has an uneven portion similar to the manual operation input ring 17 and the friction washer 21, and can be engaged with the uneven portion of the inner peripheral surface of the manual operation ring 17. There is.

Reference numeral 22 denotes a lens holder drive arm fixed to the ring 20 by a screw 23.
It is fixed to the lens holder 5 through a hole penetrating the peripheral surface of the cylindrical body 2 and is engaged with a focus roller 28 which is radially attached to the optical axis.

At the fitting portion between the manual operation ring 4 and the outer cylinder 1, three V-shaped grooves are provided in the inner peripheral portion of the manual operation ring 4 in the circumferential direction, and the ball 29 and the spring are provided on the outer peripheral surface of the outer cylinder 1. The V-shaped groove, the ball 29, and the spring are provided with three click positions for moving the manual operation ring 4 in the optical axis direction.

Next, the operation of the lens barrel of this embodiment having the above structure will be described.

First, when the thrust position of the manual operation ring is in the state of FIG. 1, when the user of the lens barrel tries to drive the lens holder 5 by the force of the vibration wave motor 26, focusing (not shown) is performed. Operate the switch. Then, a voltage is applied to the electrostrictive element 7 by the operation of a control circuit (not shown), and as a result, vibration that advances in the circumferential direction is generated in the vibrating member 6, and the vibration of the vibrating member 6 causes rotation of the rotary cylinder 13 and the rubber ring. A rotor composed of 14 and the circumferential moving member 15 is rotated about the optical axis Z. Due to the rotation of the rotor, the hollow roller 18 receives a rotation torque from the rotary cylinder 13, but at this time, since the ring 17 is not rotated because the manual operation ring 4 is not rotated, the roller 18 does not rotate. While rolling around, the roller 20 rolls along the end surface of the ring 17, and the ring 20 is rotated about the optical axis Z via the roller support shaft 19. Therefore, the lens holder drive arm 22 is also rotated around the optical axis Z together with the ring 20, so that the lens holder 5 is rotated around the optical axis Z and axially moved to perform autofocusing.

On the other hand, when the lens barrel user wants to drive the lens holder 5 by the force of the finger without driving the lens holder 5 by the force of the vibration wave motor 26, the manual operation ring 4 is operated without operating the focusing switch. It is rotated with a finger about the optical axis Z. Then, the ring 17 overcomes the frictional resistance with the friction washer 21 and rotates about the optical axis Z. However, since the vibration wave motor 26 is not driven at this time, the rotary cylinder 13 which is the rotor of the motor.
Is stationary, so the roller 18 is
It rolls along the end surface of the rotary cylinder 13 while being rotated by 7. As a result, the ring 20 is rotated about the optical axis Z via the roller support shaft 19, and the lens holder 5 is axially moved while being rotated by the drive arm 22 for manual focusing.

In this embodiment, the rotation ratio between the rotary cylinder 13 and the ring 20 and the rotation ratio between the manual operation force input ring 17 and the ring 20 are designed to be 2: 1.

Next, in the case of the state of FIG. 2, the manual operation ring 4 is moved to the right in the figure, and the engagement between the uneven portion on the inner circumference of the manual operation ring and the outer circumference of the manual operation input ring 17 is released. The manual operation ring 4 is newly clicked at a position to be engaged with the uneven portion on the outer peripheral portion of the ring 20, and is fixed substantially in the optical axis direction.

When the manual operation ring 4 is rotated around the optical axis in this state, the ring 20 is rotated together by the engagement with the uneven portion on the inner circumference. Therefore, the lens holder drive arm 22 fixed to the ring 20 also rotates in the same manner, and the lens holder 5 is rotated via the focus roller 28 to advance and retreat in the optical axis direction.

In the above case, the rotation ratio between the manual operation ring 4 and the ring 20 is 1: 1 and the rotation amount of the ring 20 due to the rotation of the manual operation ring can be changed as compared with the state of FIG. it can.

Next, in the case of the state of FIG. 3, the manual operation ring 4 is moved to the left in the figure, and from the state of FIG. 1, the uneven portion of the inner circumference of the manual operation ring and the outer peripheral portion of the manual operation input ring 17 are moved. Is disengaged from the concavo-convex portion and is newly engaged with the concavo-convex portion provided on the outer peripheral portion of the friction washer 21. At that time, since the manual operation ring 4 is clicked, it is substantially fixed in the optical axis direction.

In this state, the manual operation ring 4 is fixed to the friction washer 21 in the direction of rotation about the optical axis, and since the friction washer 21 is also fixed to the tubular body 2, the manual operation ring 4 is rotated. Fixed in the direction. At this time, since the autofocus drive by the vibration wave motor is possible, only the autofocus mode is set. Therefore, it is possible to prevent a disturbance from the outside of the lens barrel through the manual operation ring 4, so that the focus is not accidentally deviated.

[0036]

As described above, the lens barrel of the present invention provides the following operations.

(1) Manual focusing can be performed immediately after the automatic focusing operation.

(2) In contrast to the manual focusing in (1), it is possible to perform gear shifting in manual focusing (in this embodiment, the speed is doubled).

(3) The manual operation ring is locked so that only autofocusing is possible, and it is possible to prevent focus deviation due to disturbance from the outside of the lens.

Since the switching operation of (1) to (3) is possible only by moving the manual operation ring in the optical axis direction,
The operator only needs to have the manual ring in hand, which enables smooth switching operations and manual focusing operations.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a lens barrel according to the present invention.

FIG. 2 is a sectional view showing an embodiment of a lens barrel according to the present invention.

FIG. 3 is a sectional view showing an embodiment of a lens barrel according to the present invention.

FIG. 4 is a top development view of FIG. 1.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Outer cylinder 2 ... Cylindrical body 3 ... Fixed cylinder 4 ... Manual operation ring 5 ... Lens holder 6 ... Vibration member 7 ... Electrostrictive element 8 ... Disc spring 9 ... Spacer 10 ... Vibration absorber 12 ... Nut 13 ... Rotating cylinder 14 ... Rubber ring 15 ... Circumferential movement member 16 ... Vibration member rotation stop member 17 ... Manual operation input ring 18 ... Roller 19 ... Roller support shaft 20 ... (Bearing) ring 21 ... Friction washer 22 ... Lens holder drive arm 23 ... Screw 24 ... Screw 25 ... Driving force generating unit 26 ... Vibration wave motor 27 ... Bearing 28 ... Focus roller 29 ... Click ball spring 30 ... Mount

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location 9119-2K G02B 7/11 P 7316-2K G03B 3/00 A

Claims (4)

[Claims] 1. An ultrasonic motor for automatic drive, a manual operation input ring for manual operation, and a rotary member that is rotated by the drive of the ultrasonic motor. In a lens barrel having an output member that is rotationally driven by the manually operated input ring by transmission of rotational force, the lens barrel has a plurality of ratios of a movement amount of the lens moving member to a rotation angle of the external operation member, and A lens barrel having selection switching means capable of selecting a ratio of a movement amount. 2. The lens barrel according to claim 1, wherein the selection switching means is configured such that the external operating member selectively switches engagement between the manual operating ring and the output member. 3. The selection switching means according to claim 1, wherein the external operation member selectively switches engagement between the manual operation ring, the output member, and the fixed member that holds the engagement state with the manual operation ring. A lens barrel characterized by being configured as. 4. The lens barrel according to claim 2, wherein the selection switching means is switched by moving the external operation member along the optical axis direction.