JPH10160998A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out the driving of a focusing lens moving ring without the changeover operation of automatic focusing driving and a manual focusing driving by bringing a rotation transmission member with a gear into pressurized contact with a manual focusing operation ring and interlocking this rotation transmission member with the gear and the focusing lens moving ring. SOLUTION: The rotation transmission member 1 with the gear is brought into pressurized contact with the end on the rotor 17 side of the vibration wave motor of the manual focusing operation ring 11 and is rotationally moved circumferentially around the optical axis while rotating around a revolving shaft 16 at the end on the rotor 17 side of the vibration wave motor of the manual focusing operation ring 11 as a floor surface by the rotation of the rotor 17. A cam cylinder 3 is rotated by means of the gear part 1b of the rotation transmission member 1 with the gear, the gear part 4b and projecting part 4a of the focusing lens moving ring 4 and the groove 3a of the cam cylinder. The focusing lens FL fixed together with a lens chamber 5 by the cam cylinder 3 and the cam groove disposed at a stationary cylinder is moved via rollers in an optical axis direction, by which the focusing is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel having a vibration wave motor, and more particularly to a transmission mechanism for driving a focus lens without switching between auto focus driving and manual focus driving.

[0002]

2. Description of the Related Art Conventionally, a transmission mechanism for driving a focus lens without switching between auto focus drive and manual focus drive of a lens barrel having a vibration wave motor has been disclosed in Japanese Patent Application Laid-Open Nos. 2-253214 and 2-253214. Japanese Patent Application Laid-Open No. 2-253217 discloses a method of operating an autofocus mechanism and a manual focus mechanism without switching, with a rotation about a rotation axis in a radial direction orthogonal to an optical axis fixed to a focus lens moving ring. A roller capable of driving the vibration wave motor, and pressing the roller in a direction of the optical axis between the rotor and the manual focus operation ring. Even if driven, the roller is rotated to move the focus lens Transmission mechanism for actuating is disclosed.

Further, Japanese Patent Application Laid-Open No. Hei 2-253210 discloses that
By rolling a large number of freely rolling spherical rolling elements around a rotating ring member that rotates the focus lens moving ring between a rotor that is a driving unit of the vibration wave motor and a manual focus operation ring, A transmission mechanism that rotates the roller to operate the focus lens moving ring regardless of whether the rotor or the manual focus operation ring is driven is disclosed.

[0004] The transmission mechanism in which the rotor of the vibration wave motor drives the focus lens moving ring via a roller or a spherical rolling element as described above employs a manual focusing operation ring when the focus lens moving ring is driven by the vibration wave motor. Since the roller or the spherical rolling element rotates in the circumferential direction, the reduction ratio between the rotor or the spherical rolling element and the focus lens moving ring is basically 2: 1.

[0005]

Problems to be Solved by the Invention
No. 4 and JP-A-2-253217 disclose a rotor and a manual focus operation ring using a stepped roller as a roller pressed and held by the rotor and the manual focus operation ring. The reduction ratio can be changed by holding the pressure contact part with a diameter difference and pressing and holding, but if the reduction ratio is to be increased, the diameter difference of the stepped roller must be widened, and as a result, the roller The size of the mechanism must be increased.

[0006] In the transmission mechanism disclosed in Japanese Patent Application Laid-Open No. 2-253210, since the spherical rolling element is pressed and held between the rotor and the manual focus operation ring, the reduction ratio cannot be changed.

As described above, in the transmission mechanism for driving the focus lens moving ring without switching between the auto focus drive and the manual focus drive of the lens barrel having the vibration wave motor, the vibration wave motor and the focus lens movement It was difficult to increase the reduction ratio with the ring.

For this reason, a lens barrel with a large moving distance of the focus lens moving ring or a heavy lens barrel with a moving focus lens moving ring cannot be relieved when the driving torque of the vibration wave motor is insufficient. However, there is no other method than using a vibration wave motor with a larger torque, which has been a major obstacle to development including cost.

[0009]

In order to solve the above-mentioned problems, a lens barrel according to the present invention has a rotation axis perpendicular to an optical axis fixed to a rotor portion of the vibration wave motor, and the rotation axis is centered on the rotation axis. The rotation transmission member with gears is brought into contact with the manual operation ring under pressure, and the rotation transmission member with gears and the focus lens moving ring are interlocked.

With the above configuration, the purpose of driving the focus lens moving ring without switching between auto focus driving and manual focus driving and the reduction ratio of the vibration wave motor to driving the focus lens moving ring. Can be achieved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the lens barrel of the present invention, when a focus lens is moved by a vibration wave motor, a driving operation is first performed by a user by operating a focus operation switch, and a vibration circuit is operated by a control circuit. Rotor rotates about the optical axis. The rotor, stator, stator guide, and rotation transmission member with gear are pressed against the manual focus operation ring by a spring, so that the rotation transmission member with gear cannot fully resist the friction between the manual focus operation ring and the holding cylinder and the optical axis. Rotate about a rotation axis orthogonal to.
The rotation of the geared rotation transmitting member causes the focus lens moving ring and the cam barrel to rotate about the optical axis via the interlocking of the gear portion of the geared rotation transmitting member and the gear portion of the focus lens moving ring. With this rotation, the lens mirror chamber is moved in the optical axis direction via rollers by the cams cut into the fixed cylinder and the cam cylinder, thereby enabling a focusing operation.

The reduction ratio between the rotor and the manual focus operation ring at this time is determined by the length of the roller portion of the rotation transmission member with gears versus the length of the roller portion of the rotation transmission member with gears. Is the ratio obtained by subtracting the development length of the PCD diameter. Incidentally, if the difference between the diameter of the roller portion and the PCD diameter of the gear portion is large, the gear ratio is small, and if the difference is small, the gear ratio is large.

When the user manually rotates the manual focus operation ring to move the focus lens moving ring, the rotation of the manual focus operation ring causes the rotation transmission member with gears to rotate the rotor of the vibration wave motor. The rotor rotates about an axis of rotation orthogonal to the optical axis fixed to the rotor of the vibration wave motor without being able to withstand the friction of the stator. By this rotation, the focus lens moving ring and the cam barrel rotate about the optical axis through the interlocking of the gear portion of the geared rotation transmitting member and the gear portion of the focus lens moving ring. With this rotation, the lens mirror chamber is moved in the optical axis direction via rollers by the cams cut into the fixed cylinder and the cam cylinder, thereby enabling a focusing operation.

At this time, the reduction ratio between the manual focus operation ring and the focus lens moving ring becomes equal to the ratio of the diameter of the roller portion of the rotation transmission member with gear to the diameter of the PCD of the gear portion. Incidentally, if the difference between the diameter of the roller portion and the PCD diameter of the gear portion is large, the gear ratio increases, and if the difference decreases, the gear ratio decreases.

As described above, the lens barrel of the present invention can be freely selected from both the manual focus operation ring and the vibration wave motor without switching operation to perform the focusing operation. The reduction ratio can be changed by changing the ratio between the diameter of the roller portion of the member and the PCD diameter of the gear portion.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a lens barrel according to the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a lens barrel according to the present invention, and FIG. 2 is a sectional view showing the vicinity of a rotation transmitting member with gears.

1 and 2, FL is a focus lens, L is a fixed lens, 1 is a rotation transmission member with gears,
1a is a roller portion of the rotation transmission member with gears, 1b is a gear portion of the rotation transmission member with gears, 2 is a fixed cylinder, 3 is a cam cylinder, 3a
Is a cam cylinder groove, 4 is a focus lens moving ring, 4a is a focus lens moving ring projection, 4b is a focus lens moving ring gear section, 5 and 31 are lens mirror chambers, 10 is a focus lens moving ring presser, 11 is Manual focus operation ring, 13 is a holding cylinder, 14 and 38 are rollers,
16 is a rotating shaft, 17 is a rotor, 18 is a stator, 1
9 is a spring, 20 is a spring base, 22 is a stator stop,
23 is a stator guide, 24 is a mount, 25 is a rear cylinder, 28 is a throttle housing, 29 is an internal hood, 32 is a diaphragm plate, 33 is an aperture plate,
34 is an electrostrictive element, 35 is a vibration absorber, and 36 is a sliding surface lubricant.

In FIGS. 1 and 2, the fixed cylinder 2 has a holding cylinder 13 screwed to it. The lens mirror chamber 5 slides through the rollers 38 along the cam grooves of the fixed cylinder 2 and the cam cylinder 3 along the inner diameter of the fixed cylinder 2. The cam cylinder 3 is fitted so as to rotate only within an angle range restricted by the outer diameter of the fixed cylinder 2,
The end of the vibration wave motor on the rotor 17 side has a cam cylinder groove 3a for interlocking with the focus lens moving ring 4, and is connected to the protrusion 4a of the focus lens moving ring 4. The focus lens moving ring 4 is rotatably held by the holding cylinder 13 and the focus lens moving ring retainer 10, and is provided with a gear portion 4b that is interlocked with the gear portion 1b of the geared rotation transmitting member 1. In this embodiment, a crown gear is used for 4b. The manual focus operation ring 11 is attached so as to be freely rotatable 360 ° by a roller 14 attached to the outer diameter of the holding cylinder 13. The end of the vibration wave motor on the rotor 17 side is a rotation transmission member with gears. It is a rotation surface of the roller portion 1a of the rotation transmission member 1 with gear 1. The rotation transmission member 1 with gear rotates about a rotation axis 16 whose rotation surface is orthogonal to the optical axis of the lens fixed to the rotor 17.

The vibration wave motor includes a stator 18 as an annular vibration member to which an electrostrictive element 34 is adhered, an annular vibration absorber 35 made of a material for absorbing vibration such as felt or rubber, and the vibration absorber. An annular stator guide 23 disposed in contact with one end face of the first stator 35, and a spring 1 for pushing the stator guide 23 toward the stator 18.
9, a spring base 20 for holding down the spring 19, a stator stop 22 for stopping rotation of the stator 18, and a rotor 17 having a sliding surface lubricant 36 adhered to the rotor 17 rotated by the vibration of the stator 18. Have been.

The rotor 17, the rotating shaft 16 and the geared rotation transmitting member 1 are integrally rotated in the circumferential direction around the optical axis by the traveling wave vibration wave generated by the stator 18. At this time, the stator guide 23, the vibration absorber 35, the stator 18, the rotor 17, and the rotating shaft 1 sandwiched between the spring base 20 and the manual focus operation ring 11.
6. The geared rotation transmitting member 1 is pressed and held by a spring 19. For this reason, the geared rotation transmitting member 1 is pressed against the end of the manual focus operation ring 11 on the rotor 17 side of the vibration wave motor, and the rotation of the rotor 17 causes the manual focus operation ring 11 on the rotor 17 side of the vibration wave motor. Rotating shaft 16 with end at floor
While rotating about the optical axis, and rotate in the circumferential direction about the optical axis. The rotation of the geared rotation transmitting member 1 causes the cam barrel 3 to rotate through the gear portion 1b of the geared rotation transmitting member 1, the gear 4b of the focus lens moving ring 4, the protrusion 4a, and the cam barrel groove 3a. The focus lens FL fixed together with the lens mirror chamber 5 by the cam grooves provided in the cam barrel 3 and the fixed barrel 2 is moved in the optical axis direction via the roller 38 to perform focusing. At this time, the reduction ratio between the rotor 17 and the manual focus operation ring 11 is determined by the length of the roller portion of the geared rotation transmitting member versus the length of the roller portion of the geared rotation transmitting member. The ratio is obtained by subtracting the development length of the PCD diameter. Incidentally, when the difference between the diameter of the roller portion 1a and the PCD diameter of the gear portion 1b is large, the gear ratio is small, and when the difference is small, the gear ratio is large.

On the other hand, when the photographer performs a focusing operation from the manual focus operation ring 11, when the manual focus operation ring 11 is manually rotated, the roller portion 1a of the geared rotation transmitting member 1 Since it is in pressure contact with the end of the vibration wave motor on the rotor 17 side, the frictional force between the rotating shaft 16 and the geared rotation transmitting member 1 is smaller than the frictional force between the stator 18 and the rotor 17. The geared rotation transmitting member 1 rotates independently around the rotation shaft 16. The rotation of the geared rotation transmitting member 1 is controlled by the gear portion 1 b of the geared rotation transmitting member 1, the gear 4 b of the focus lens moving ring 4, and the projection 4.
a, the cam cylinder 3 is rotated through the cam cylinder groove 3a, and the focus lens FL fixed together with the lens mirror chamber 5 by the cam groove provided in the cam cylinder 3 and the fixed cylinder 2 moves the roller 38 in the optical axis direction. Focusing is performed by moving through. At this time, the reduction ratio between the manual focus operation ring 11 and the focus lens moving ring 4 is equal to the ratio of the diameter of the roller portion 1a of the geared rotation transmitting member 1 to the diameter of the PCD of the gear portion 1b. By the way, the diameter of roller part 1a and PCD of gear part 1b
If the diameter difference is large, the gear ratio is large, and if the difference is small, the gear ratio is small.

[0023]

As described above, according to the present invention, it is possible to perform a focusing operation freely from both the manual focus operation ring and the vibration wave motor. Even when performing focus shooting, it is possible to immediately shift to manual focus operation, and the operability of the photographer can be improved. Furthermore, a large reduction ratio can be obtained by changing the ratio between the diameter of the roller portion of the rotation transmission member with gears and the diameter of the PCD of the gear portion by design. It is possible to obtain an appropriate reduction ratio even for a lens moving ring having a large operating torque, such as a large-aperture telephoto lens in which the lens becomes large and heavy.

Note that a ball bearing such as a bearing may be provided in the rotation transmission member with gears in order to improve the rotation of the rotation transmission member with gears, and the spring for applying pressure is changed to a leaf spring, a wave washer, or the like. Needless to say, there is no problem.

[Brief description of the 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 the vicinity of a geared rotation transmitting member according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotation transmission member with gear 2 Fixed cylinder 3 Cam cylinder 4 Focus lens moving ring 5 Lens mirror room 10 Focus lens moving ring holding 11 Manual focus operation ring 13 Holding cylinder 14 Roller 16 Rotary shaft 17 Rotor 18 Stator 19 Spring 20 Spring base 22 Stator Stop 23 Stator guide 24 Mount 25 Rear cylinder 28 Aperture housing 29 Inner hood 31 Lens mirror room 32 Diaphragm plate 33 Aperture plate 34 Electrostrictive element 35 Vibration absorber 36 Sliding surface lubricant 38 Roller

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 7, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

The speed reduction ratio between the rotor and the manual focus operation ring at this time is determined by the length of the roller portion of the geared rotation transmitting member versus the length of the roller portion of the geared rotation transmitting member. "The difference is that the difference between the diameter of the roller portion and the PCD diameter of the gear portion is large, and the smaller the difference, the larger the gear ratio is." The reduction ratio between the rotor and the focus lens moving ring is determined by the length of the roller portion of the geared rotation transmitting member versus the deployed length of the roller portion of the geared rotation transmitting member.
The ratio is obtained by subtracting the development length of the CD diameter. Incidentally, if the difference between the diameter of the roller portion and the PCD diameter of the gear portion is large, the gear ratio is small, and if the difference is small, the gear ratio is large. Will be corrected.

Claims (1)

[Claims] 1. A lens barrel having a vibration wave motor concentric with an optical axis of a lens, a driving member of the vibration wave motor having a rotation axis orthogonal to the optical axis fixed, and a center of the rotation axis. A geared rotation transmitting member, a pressurizing means for bringing the geared rotation transmitting member into pressure contact with a manual operation ring, and a focus lens moving ring rotatable with respect to a fixed barrel of the lens barrel A lens barrel having an interlocking unit that interlocks the geared rotation transmitting member and the focus lens moving ring.