JPH06273659A - Zoom lens barrel - Google Patents

Abstract

(57) [Abstract] [Purpose] To achieve miniaturization by determining the diameter of the zoom lens barrel without being restricted by the outer diameter of the lens group used for focusing. [Configuration] First to third lens groups are provided, the first lens group and the second lens group sandwich an aperture, and the second lens group and the third lens group.
The zooming operation is performed by changing the distance from the lens group.
In a zoom lens barrel that performs focusing by moving the lens group in the optical axis direction, a diaphragm drive mechanism that is arranged on the outer periphery of the first lens group and drives an aperture, and a camera shake that is arranged on the outer periphery of the second lens group. An image stabilization mechanism for driving the correction optical system and a driving force transmitting means for transmitting the driving force of the diaphragm driving mechanism to the third lens group are provided, and the driving force of the diaphragm driving mechanism is controlled by the third driving force transmitting means. Focusing is performed by transmitting to the lens group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zoom lens barrel used for a camera or the like.

[0002]

2. Description of the Related Art In a zoom lens barrel used in a conventional camera or the like, focusing driving means is arranged around a focusing lens group, and diaphragm driving means is arranged around a lens group closest to a diaphragm. Was common.

[0003]

However, the focusing lens group of the zoom lens has a relatively large diameter, and when the focusing driving means is arranged around the focusing lens group, the space required for the focusing driving means is reduced. There is a problem that the diameter of the lens barrel becomes large.

The present invention has been made in view of the above problems, and it is possible to reduce the size of the zoom lens barrel by determining the diameter of the zoom lens barrel without being restricted by the outer diameter of the lens group for focusing. To aim.

[0005]

In order to achieve this object, a zoom lens barrel of the present invention has first to third lens groups, and the first lens group and the second lens group sandwich an aperture. , A zoom lens barrel that performs a zooming operation by changing the distance between the second lens group and the third lens group and performs focusing by moving the third lens group in the optical axis direction. A diaphragm driving mechanism that is arranged on the outer circumference to drive the diaphragm, a shake correcting mechanism that is arranged on the outer circumference of the second lens group to drive the camera shake correction optical system, and the driving force of the diaphragm driving mechanism is transmitted to the third lens group. And a driving force transmitting means, which is configured to perform focusing by transmitting the driving force of the diaphragm driving mechanism to the third lens group via the driving force transmitting means.

[0006]

In the zoom lens barrel having the above structure, the first
Since the diaphragm driving mechanism arranged on the outer periphery of the lens group is configured to transmit the driving force to the third lens group for performing the focusing through the driving force transmitting means to perform the focusing, the outer diameter of the third lens group The diameter of the zoom lens barrel can be determined without being restricted by the above, and downsizing can be achieved.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

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

In FIG. 1, reference numerals 1 to 4 denote zoom lens groups, and the first lens group 2 and the second lens group 3 are integrally formed. 5 is a lens chamber of the first lens group 2,
Reference numeral 6 denotes a diaphragm / shutter driving unit having focusing driving means. Reference numeral 7 denotes a lens substrate to which the diaphragm / shutter driving unit 6 is fixed by screws 21. The lens substrate 7 has a camera shake correction mechanism, which will be described later with reference to FIG. Reference numeral 8 denotes a lens chamber for the lens group 2 which is fixed to the diaphragm / shutter driving unit 6. Reference numeral 10 is a lens substrate for the lens group 3, and a female helicoid screw 10b is provided on the inner circumference.
Is formed and is screwed with a male helicoid screw 11b formed on the outer periphery of the lens chamber 11. The rotation of the lens chamber 11 causes the lens chamber 11 to move back and forth in the optical axis direction, thereby performing focusing.

Reference numeral 14 denotes a fixed barrel, which has linear guide holes 14a and 14b through which the cam followers 5a, 7c and 10a of the lens groups 1 to 4 pass. Cam tube 13
Holds the lens groups 1 to 4 on its inner wall,
The optical axis eccentricity of 4 is suppressed within a predetermined value. The cam barrel 13 engages with the outer periphery of the fixed barrel 14, and the ring 15 prevents the cam barrel 13 from falling off. A gear 15 a is formed on the outer circumference of the cam barrel 13, and the gear 15 a meshes with a pinion gear 23 via a reduction gear series 22. Pinion gear 23
Are directly connected to the zoom motor M1, and therefore the cam barrel 13 rotates as the zoom motor M1 rotates.

The zoom motor M1 has a switch S
The forward rotation or the reverse rotation is performed by turning on / off the W3 or the switch SW4. Three cam grooves 13a to 13c are formed on the inner wall of the cam barrel 13, and the tip conical portions of the cam followers 5a, 7c, and 10a of the lens groups 1 to 4 are engaged with each other. As a result, the lens groups 1 to 4 move in the optical axis direction as the cam barrel 13 rotates.

FIG. 2 is a schematic front view showing an embodiment of the zoom lens barrel according to the present invention. FIG. 3 is a conceptual diagram for explaining the operation of an embodiment of the zoom lens barrel according to the present invention. FIG. 4 is a schematic front view and a partial sectional view showing an embodiment of the zoom lens barrel according to the present invention.

In FIG. 2, reference numeral 40 denotes a pinion gear connected to a stepping motor (not shown), which meshes with a gear 39b formed as a part of the drive ring 39. When the switch SW1 of FIG. 1 is turned on, photometry and distance measurement are performed, and when the switch SW2 is turned on, a stepping motor (not shown) rotates and the drive ring 39 starts to rotate clockwise. A limiter 39c is formed on the drive ring 39 and engages with a limiter 41b formed as a part of the focusing ring 41. Since the drive ring 39 is biased in the clockwise direction by the tension spring 42, the focusing ring 41 also rotates in the clockwise direction as the drive ring 39 rotates.

When the rotation speed of a stepping motor (not shown) reaches a predetermined rotation speed calculated from the distance measurement data, the magnet 44 is energized to open the ratchet pawl 43a and engage the ratchet 41a. Stop the focusing ring 41. The focusing ring 41 is shown in FIG.
And as shown in FIG. 1, it engages with the transmission arm 54 via the pin 41b (FIGS. 2 and 3). The transmission arm 54 is connected to the lens chamber 1 via the shaft 25 and the transmission arm 56.
The rotational force is transmitted to 1, and the focusing drive of the third lens group 4 is performed.

In FIG. 2, after the ratchet pawl 43a is released, the drive ring 39 further rotates and the limiter 39a of the drive ring 39 engages with the limiter 38d of the sector opening / closing ring 38. The sector opening / closing ring 38 is biased in the counterclockwise direction by a spring 46, but the limiter 39a engages with the limiter 38d to rotate the drive ring 39 in the clockwise direction. Rotate to.

The sector opening / closing ring 38 has pins 38a ...
38c is planted. The pins 38a to 38c pass through the elongated holes 35a to 37a of the sector blades 35 to 37 (see FIG. 4). The sector opening / closing ring 38 rotates, and the sector blades 35-37 rotate about the rotation shafts 32-34, whereby the sector blades 35-37 form a shutter that also serves as an aperture.

When the sector blades 35 to 37 are used as diaphragms, the CP based on the photometric value of the photometric means 66 is used.
From the result calculated by the U circuit 61, a stepping motor (not shown) is passed through a shutter motor driver 63 that also serves as an aperture.
The exposure control is performed by controlling the stop reversal timing of 1 to control the size of the opening 50 and the opening time.

After the exposure control operation is completed, the stepping motor (not shown) is reversed and the focusing ring 4 is rotated.
1 is reversed, and the ratchet claw 43a is engaged with the projection 41c so that the ratchet claw 43a is attracted to the magnet 44, thereby resetting the aperture / shutter.

FIG. 5 is a sectional view of a camera shake correction mechanism in an embodiment of the zoom lens barrel according to the present invention.
FIG. 9 is a sectional view taken along line AA of Referring first to FIG. 5, the Y-direction image stabilization mechanism will be described.

The second lens group 3 is supported by the lens holder 9. A connecting portion 9a is provided on the upper portion of the lens holder 9.
Is formed, and the connecting portion 9a includes four slider balls 25.
The slider balls 25a to 25d are supported by a to 25d and are in point contact with each other. The slider balls 25a to 25d are held by the Y-direction shift driving arm 24. Therefore, the lens holder 9 moves integrally with the Y-direction shift driving arm 24 in the Y direction, but freely moves in the X direction.

The Y-direction shift drive arm 24 is screwed with a gear 26b formed at the lower end (FIG. 5) of the Y-direction shift drive shaft 26. The Y-direction shift drive shaft 26 includes the flange portion 2
The lens substrate 7 is rotatably supported by 6c and 26d. As a result, when the Y-direction shift drive shaft 26 rotates, the Y-direction shift drive arm 24 is moved in the Y direction. The gear 2 is attached to the upper end (FIG. 5) of the Y-direction shift drive shaft 26.
6a is formed, and the gear 26a meshes with the pinion gear 28 via the reduction gear 27. The pinion gear 28 is directly connected to the motor M3, so that the lens holder 9 moves in the Y direction as the motor M3 rotates.

An encoder 29 is coaxially formed on the pinion gear 28, and the rotation of the motor M3 together with the photo interrupter 30 is converted into an electric signal and the CPU circuit 61 is formed.
Have been communicated to. Transmission of this electric signal and supply of drive power for the motor M3 are performed by an FPC (Flexible print circuit) 1
6 (FIG. 1). The FPC 16 also transmits drive power to the diaphragm / shutter driving unit 6, and therefore is also connected to the diaphragm / shutter motor driver 63 and the camera shake correction motor driver 64.

The X-direction camera shake correction mechanism is the same as the Y-direction camera shake correction mechanism, and a duplicate description will be omitted. X direction and Y supplied from the hand shake sensor 68
The camera shake correction amount is set according to the shake amount in the direction.
And drives the motor M3 (Y direction) and the motor M4 (X direction) via the camera shake correction motor driver 64. Driven by the motors M3 and M4, the lens holder 9 (lens group 3) shifts in the Y direction and the X direction to perform camera shake correction.

The shift movement of the lens group 3 for camera shake correction must be performed in a direction that coincides with the direction detected by the camera shake sensor 68. When the camera shake sensor 68 is arranged at a position different from that of the camera shake correction lens shift mechanism, the matching between the detection direction and the correction direction is determined by the camera shake sensor 6.
8 according to the stacking amount of the dimensional error of the parts existing between the camera shake correcting lens shift mechanism 8 and the camera shake correcting lens shift mechanism. Generally, the larger the number of intervening parts, the larger the stacking amount of dimensional error.

According to the embodiment described above, the focus actuator (the diaphragm / shutter drive unit 6 having the focusing drive means) and the focus lens (lens group 4) are separately arranged, so that the outer diameter of the focus lens can be adjusted. The diameter of the zoom lens barrel can be determined without any restriction, and the size can be reduced.

Further, since a focusing actuator (a diaphragm / shutter driving section 6 having a focusing driving means) is arranged near the shutter section (a diaphragm / shutter driving section 6), the distance between the two does not change. Since the FPC and the FPC of the focusing actuator can be integrated, the structure of the FPC can be simplified and the cost can be reduced.

[0027]

As described above, according to the zoom lens barrel of the present invention, the diaphragm drive mechanism arranged on the outer periphery of the first lens group is connected to the third lens group for focusing via the driving force transmission means. Since the driving force is transmitted to perform the focusing, the size can be reduced by determining the diameter of the zoom lens barrel without being restricted by the outer diameter of the focusing lens group. .

[Brief description of drawings]

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

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

FIG. 3 is a conceptual diagram illustrating the operation of an embodiment of the zoom lens barrel according to the present invention.

FIG. 4 is a schematic front view and a partial sectional view showing an embodiment of the zoom lens barrel according to the present invention.

FIG. 5 is a sectional view of a camera shake correction mechanism in an embodiment of the zoom lens barrel according to the present invention.

[Explanation of symbols]

 1 to 4 lens group 5a cam follower 6 also serving as shutter drive section 7 lens substrate 9 lens holder 9a connecting section 10b female helicoid screw 11 lens chamber 11b male helicoid screw 13 cam barrel 13a cam groove 14 fixed barrel 14a linear guide hole 15 ring 15a gear 16 FPC 21 Screw 22 Reduction gear series 23 Pinion gear 24 Y-direction shift drive arm 25a Slider ball 26 Y-direction shift drive shaft 26a Gear 26b Gear 26c Flange portion 27 Reduction gear 28 Pinion gear 29 Encoder 30 Photointerrupter 32 Rotation shaft 35 Sector blade 35a Slotted hole 38 Sector opening / closing ring 38a pin 38d Limiter 39 Drive ring 39a Limiter 39b Gear 39c Limiter 41 Focusing ring 41a Ratchet 41b Pin 1b limiter 41c projection 42 a tension spring 43a ratchet pawl 44 magnet 46 spring 50 opening 54 transmission arm 56 transmitting arm 61 CPU circuit 63-shutter motor driver 64 corrects the motor driver 66 photometry means 68 sensor

Claims (1)

[Claims] 1. A variable magnification operation is provided by having first to third lens groups, a first lens group and a second lens group sandwiching an aperture, and changing a distance between the second lens group and the third lens group. A zoom lens barrel that performs focusing by moving the third lens group in the optical axis direction, an aperture driving mechanism that is arranged on the outer periphery of the first lens group to drive the aperture, and the second lens group. A shake correction mechanism that is disposed on the outer periphery of the diaphragm to drive the shake correction optical system; and a driving force transmission unit that transmits the driving force of the diaphragm driving mechanism to the third lens group. Is transmitted to the third lens group via the driving force transmission means to perform focusing, and a zoom lens barrel.