JP2503997B2 - Lens barrel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention relates to a lens mirror in which a lens barrel main body including a fixed barrel and a movable barrel is equipped with an ultrasonic motor as a drive source for moving the movable barrel Regarding the cylinder.

"Prior art" In a lens barrel using an ultrasonic motor, as a technique for switching between an automatic mode in which the taking lens is driven by the rotational force of the ultrasonic motor and a manual mode in which the taking lens is driven manually 59-101608 publication, etc., the pressing force of the rotor and the stator is changed, the stator and the rotor are separated,
It is known to switch by contact, and to rotate the stator and the rotor constantly in the manual mode as in JP-A-61-86718.

[Problems to be Solved by the Invention] However, in the lens barrel using the conventional ultrasonic motor, as described above, the manual operation cannot be performed in the automatic mode, and the lens barrel is not easy to use. There was a point.

Therefore, an object of the present invention is to provide a lens barrel that can be manually operated even when the photographing lens is driven by rotation of the rotor of the ultrasonic motor.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a fixed barrel (2) provided with a manual ring (10) for focusing, and a focusing lens (2a).
And a movable barrel (16) that is movable relative to the fixed barrel (2) in the optical axis direction, and a stator (3a) that drives the movable barrel (16).
And a lens barrel including an ultrasonic motor (3) having a rotor (3b) for rotating the stator (3a), interposed between the moving barrel (16) and the rotor (3b), A driving force transmitting means (13) for transmitting the driving force to the moving barrel (16),
The rotation of the rotor (3b) of the ultrasonic motor (3) is stopped, and the rotation of the manual ring (10) is transmitted via the driving force transmission member (13) to move the movable cylinder (16). The manual adjustment means (9, 25, 27) for adjusting the focus and the rotation of the rotor (3b) of the ultrasonic motor (3) are activated, and the operation amount and rotation of the manual ring (10) are set. Automatic adjustment means (9, 25, 25) for moving the movable barrel (16) to adjust the focus by transmitting the driving amount obtained by combining the rotation amount of the child (3b) through the driving force transmission device (13). 27) and a switching means (12) for switching between a manual adjustment means (9, 25, 27) and an automatic adjustment means (9, 25, 27).

[Operation] The present invention relates to an automatic adjusting means for driving the movable barrel (16) with a driving amount that combines the rotation amount of the rotor (3b) of the ultrasonic motor (3) and the operation amount of the manual ring (10) ( 9,25,27), the moving barrel (16) is driven by the rotation of the rotor (3b) of the ultrasonic motor (3) to manually move the focusing lens in the optical axis direction. Since the operation can be performed, the moving speed of the moving barrel (16) can be increased and the usability of the lens barrel is improved.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. Each drawing shows an embodiment of the present invention.

As shown in FIG. 1, the lens barrel 1 comprises a movable barrel 16 movably held in the fixed barrel 2 in the optical axis direction for focus adjustment via a member interposed therebetween.

The lens barrel 1 is provided with photographing optical systems 2a and 2b, of which the photographing optical system 2a, which is a focusing lens, is held by the movable barrel 16. The moving barrel 16 is provided with a key 16a and a pin 16b, and the key 16a is fitted in a key groove 15a provided in the holding barrel 15 so as to be movable in the optical axis direction.

The pin 16b is a rotary cylinder 1 rotatably held on the fixed cylinder 2 side.
It is fitted in the helicoid groove 14b provided in 4. The rotary cylinder 14 is provided so that the protrusion 14a fits into a ring groove provided inside the outer cylinder 17 that is integral with the fixed cylinder 2 side.

The outer periphery of the ultrasonic motor 3 is rotatably held by being sandwiched by the fixed ring 6 and the ring 23 and the support cylinder 19 via the roller 5.

As shown in FIG. 4, in the ultrasonic motor 3, a rotor 3b is combined with a stator 3a made of a piezoelectric element and an elastic body, an outer cylinder 3c holds the stator 3a, and the stator 3a is connected to the outer cylinder 3c. The pressing member 3d presses the stator 3a and the rotor 3b into contact with each other. Rotor
3b is rotatably pressed by the pressure member 3d by the ball race 3e.

As shown in FIGS. 1 and 4, a gear 7 for rotating the ultrasonic motor 3 about the optical axis is fixed to the outer peripheral surface 3f of the ultrasonic motor 3. The gear 7 has ring-shaped teeth facing forward at the end. Rotor of ultrasonic motor 3
A pin 4 is fixed to 3b, and the pin 4 is connected to a connecting member 13 provided on a rotary cylinder 14. The flat surface portion 3g on the rear side of the optical axis of the ultrasonic motor 3 is provided with a contact for power supply or signal transmission in the circumferential direction and is in contact with the contact 21 on the lens barrel side.

The connecting member 13, the rotary cylinder 14 and the helicoid groove 14b
And the key 16a and the pin 16b of the moving barrel 16 are interposed between the moving barrel 16 and the ultrasonic motor 3, and the moving barrel 16 receives the ultrasonic motor 3
A driving force transmission mechanism that transmits the driving force of

The teeth of the gear 7 mesh with a gear 8 provided inside the outer cylinder 17 so as to be rotatable around an axis in the radial direction.
It is integrally connected coaxially with a gear 9 provided on the outside of 17. The gear 9 meshes with a ring-shaped gear 10a provided on an end edge of a cylinder of a rotatable distance ring 10 for manual operation (hereinafter referred to as a manual ring).

A clutch gear 25 is engaged with the gear 9 so as to be rotatable around the axis of the gear 9. The clutch gear 25 and the gear 9 are engaged at one end with an engagement pin 28 and at the other end with a pivot shaft 26 of the clutch gear 25. The clutch gear 25 is retained by the gear 10a of the manual ring 10 so as to be disengageable while being engaged with the gear 9.
It is normally urged in the direction in which it meshes with the gear 9.

Manual operation in which the manual ring 10 and the gear 10a and the gears 7, 8 and 9 rotate the entire ultrasonic motor 3 to rotate the rotor 3b thereof to move the moving cylinder 16 via the drive force transmission mechanism. Constitutes a means.

A mode switching knob 12 is provided on the fixed cylinder 2 so as to be movable in the circumferential direction, and a clutch plate 11 is connected thereto. The clutch plate 11 has a clutch groove 11a having a small diameter portion and a large diameter portion.
And the pivot shaft 26 of the clutch gear 25 is inserted in the clutch groove 11a.
Are relatively slidably fitted together.

The mode switching knob 12, the clutch plate 11, the clutch groove 11a, the clutch gear 25, the gear 9, and the spring 29 are
A second automatic mode in which the operation of the manual operation means is prohibited, the stator 3a of the ultrasonic motor 3 is fixed to the fixed cylinder 2 so that they cannot rotate relative to each other, and the ultrasonic motor 3 can be activated, and a manual operation. The ultrasonic motor 3 enables the operation of the means.
The mode switching means is configured to switch between an automatic mode for enabling the start of the ultrasonic motor 3 and a manual mode for canceling the prohibition of the operation of the manual operating means and disabling the ultrasonic motor 3.

The mode switching knob 12 also serves as a power switch, and the clutch plate 11 has lead contact terminals 27a, 27a of the switch 27.
b touches. A connection cord 22 connects the switch 27 and the contact 21. A mount 20 (bayonet mount or screw mount) for attaching the lens barrel to a camera or the like is fixed to the rear side of the fixed barrel 2.

 Next, the operation will be described.

The second automatic mode in which the photographing lens is driven by the rotational force of the ultrasonic motor 3 is set by setting the mode switching knob 12 to the second automatic mode side as shown in FIGS. 5 and 6.

When the mode switching knob 12 is set to the second automatic mode side, the clutch plate 11 moves in conjunction with the mode switching knob 12,
After the state shown in FIG. 8, the shaft 26 moves to the left side in the figure along the hole 11a provided in the clutch plate 11.

Then, the gear 25, which is meshed with the gear 9 provided on the shaft 26, is meshed with the gear 9 by the spring 29, and the gear 10a.
Mesh with. When the gears 9, 10a and 25 are meshed at the same time, all three gears cannot rotate. Therefore, the gear 8 cannot rotate, the gear 7 cannot rotate, and the rotation of the manual ring 10 is prohibited.

Since the gear 7 is fixed to the outer peripheral surface 3f of the ultrasonic motor 3 and the stator 3a is fixed to the outer peripheral surface 3f, that is, the outer cylinder 3c, the stator 3a cannot be rotated after all. Also, the switch 27b moves in conjunction with the clutch plate 11 and the switch 2
7a and 27b are in contact with each other, power is supplied to the ultrasonic motor from a power source (not shown) through the contact 21, the ultrasonic motor 3 is turned on, and the rotor 3b is rotated by the motor drive signal.

Since the rotary cylinder 14 is connected to the pin 4 provided on the rotor 3b, the rotary cylinder 14 is rotated by the rotation of the rotor 3b, and the movable cylinder
16 moves back and forth in the optical axis direction to perform focus adjustment. The amount of extension of the taking optical system 2a, which is a taking lens, can be confirmed on the distance scale through the window 24.

Next, the manual mode will be described. Manual mode is second
This is set by setting the mode switching knob 12 to the manual side as shown in FIGS.

When the mode selector switch is moved downward in FIG. 6, the clutch plate 11 also moves downward, and the shaft 26 moves along the clutch groove 11a.
Moves to the right. When the shaft moves to the right, the gear 25 becomes the gear 10a.
When the prohibition of rotation of the manual ring 10 is released,
The gear 10a meshes with the gear 9, and the gear 9 and the gear 25 mesh with each other.

Further, as the clutch plate 11 moves, the switch 27b is pushed by the clutch plate 11 and separated from the switch 27a, so that the power supply to the ultrasonic motor 3 is stopped. When the gear 25 is separated from the gear 10a, when the manual ring 10 is rotated, the rotations of the gear 9, the gear 8, the gear 7 and the manual ring 10 are transmitted, and the outer cylinder 3c of the ultrasonic motor 3 rotates. When the outer cylinder 3c rotates, the stator 3a rotates.

Since the ultrasonic motor 3 is not powered, the stator
The rotating contact of the stator 3a is transmitted to the rotor 3b, and the rotary cylinder 14 connected to the rotor 3b rotates to take a picture as a photographing lens. The optical system 2a is moved and focus adjustment is performed.

7 and 8 show the automatic mode between the second automatic mode and the manual mode, in which the gear 25 is separated from the gear 10a and the switches 27a and 27b are in contact with each other.

Therefore, the rotation of the manual ring 10 causes the outer cylinder of the ultrasonic motor to rotate.
3c is in a rotatable state, and at the same time, power is being supplied to the motor, so that the ultrasonic motor can be driven. In other words, the shooting optical system 2a, which is a shooting lens, is connected to the manual ring 10
It can be moved by both the ultrasonic motor 3 and the ultrasonic motor 3. (Note that when the manual operation is too light, the operability can be changed by attaching a disk such as rubber to the shaft 28.) The embodiments of the present invention have been described above. The holding method is not limited to the method of the present embodiment, and any method may be used as long as the entire ultrasonic motor can be rotated or unrotatable. Further, although the clutch using the gear is shown for switching between the second automatic mode and the manual mode, the clutch mechanism is not limited to this method.

[Advantages of the Invention] Since the invention of the present application is provided with the automatic adjusting means for driving the movable barrel with the drive amount that combines the rotation amount of the rotor of the ultrasonic motor and the operation amount of the manual ring, the rotation of the ultrasonic motor is prevented. Even when the focusing lens is moved in the optical axis direction by driving the moving barrel by rotating the child, the moving speed of the moving barrel can be adjusted because the manual operation can be performed, and the usability of the lens barrel is improved.

Further, according to the present invention, when the automatic adjusting means is used, the focusing lens can be driven only by the rotation amount of the rotor of the ultrasonic motor by simply ending the operation of the manual ring.

Further, according to the invention of the present application, if the switching means is switched to the manual adjustment means according to the photographer's preference and shooting situation,
The focusing lens can be moved in the optical axis direction only by operating the manual ring.

BRIEF DESCRIPTION OF THE DRAWINGS Each drawing shows an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a lens barrel, and FIGS. 2 and 3 are explanations of switching operation parts in a manual mode. FIGS. 4 and 5 are transverse sectional views of the ultrasonic motor, FIGS. 5 and 6 are explanatory views of switching operation parts in the second automatic mode, and FIGS. 7 and 8 are switching operation parts in the automatic mode. FIG. 1 ... Lens barrel, 2 ... Fixed barrel 2a, 2b ... Shooting optical system 3 ... Ultrasonic motor, 10 ... Manual ring 11 ... Clutch plate, 12 ... Mode change switch 16 ... Moving barrel

Claims (1)

(57) [Claims] 1. A fixed barrel having a manual ring for focusing, a movable barrel equipped with a focusing lens and movable in the optical axis direction relative to the fixed barrel, and a stator for driving the movable barrel. In a lens barrel including an ultrasonic motor having a rotor that rotates the stator, a driving force transmission unit that intervenes between the moving barrel and the rotor and that transmits a driving force to the moving barrel. A manual adjustment means for stopping the rotation of the rotor of the ultrasonic motor and moving the movable barrel by transmitting the rotation of the manual ring via the driving force transmission member to perform focusing adjustment. And by activating the rotation of the rotor of the ultrasonic motor, and transmitting a driving amount obtained by combining the operation amount of the manual ring and the rotation amount of the rotor via the driving force transmitting means. Adjust the focus by moving the movable barrel A lens barrel and having a kinematic adjusting means, and switching means for switching between the manual adjustment means and the automatic adjustment means.