JP2000292674A - Lens-barrel frame device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a satisfactory drive condition with reduced play, to reduce the number of part items, and to prevent an occupied space from increasing. SOLUTION: This device has a lens frame 4, and a lens frame 3 guided linearly by guide shafts 5, 6 supported by the lens frame 4. The guide shaft 6 has a sliding shaft part 6a of elliptic cross-section engaged with a U-shaped cut-out part 3b in the lens frame 3, and a supporting shaft part 6b supported turnably onto the lens frame 4. The guide shaft 6 is turned with respect to the lens frame 4 to adjust a clearance with respect to the cut-out part 3b, so as to be fixed to the lens frame 4, and play in slide movement between lens frame 3 and the lens frame 4 is thereby eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens frame device capable of adjusting a sliding gap of a support portion.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. Hei 8 (1999) discloses a conventional lens frame device for optical equipment which removes backlash generated in a guide portion for guiding the lens frame to move straight, thereby reducing image shaking when the lens frame is driven forward and backward. There is a lens driving device disclosed in JP-A-110460. In this conventional lens driving device, the lens frame is supported so as to be able to move straight by a support portion fitted to a guide shaft, and has a structure driven forward and backward by a rack meshing with a feed screw. Then, in order to remove the engagement play in the feed screw and the rack and the fitting play in the support section, the rack is held by a spring member to remove the play of the rack and simultaneously apply a moment to the support section to support the support section. The play at the fitting is removed.

[0003]

However, in the lens driving device disclosed in Japanese Patent Application Laid-Open No. H8-110460, a mechanism for applying the spring member and its urging force to a mechanism portion to remove backlash. Need department,
As the number of parts increases, the occupied space also increases. In addition, since a moment is applied to the support portion, there is a problem that the sliding resistance at the time of driving the lens frame forward and backward is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a good driving state with little backlash, and has a small number of components and does not increase the occupied space. It is an object to provide a frame device.

[0005]

According to a first aspect of the present invention, there is provided a lens frame device comprising: a frame member; a linear support member having a non-circular cross-sectional shape for supporting the frame member so as to be capable of linearly moving; A guided portion that is formed and engages with the rectilinear support member, and has a guided portion that comes into sliding contact with the guide portion, and rotates the rectilinear support member around its own axis to allow the guided portion and the rectilinear support member to rotate. The gap between them can be adjusted to a minimum.

According to a second aspect of the present invention, there is provided a lens frame device, a frame member, a linear support member having a non-circular cross-sectional shape for supporting the frame member so as to be capable of linearly moving, and the linear support member formed on the frame member. A guided portion engaged with the member and slidably contacted, and a driving means for moving the frame member forward and backward in the axial direction of the linear support member, and rotating the linear support member around its own axis. Thus, the gap between the guided portion and the straight support member can be adjusted to a minimum.

According to a third aspect of the present invention, there is provided a lens frame device, a frame member, a linear support member having a non-circular cross-sectional shape for supporting the frame member so as to be able to move linearly, and the linear member is formed on the frame member. A guided portion that engages with the member and slides in contact therewith; a driving unit that advances and retreats the frame member in the axial direction of the linearly-moving support member;
By rotating the linear support member around its own axis,
Adjusting means for adjusting the gap between the guided portion and the straight support member to a minimum, and adjusting the gap between the guided portion and the straight support member to a minimum. is there.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view along an optical axis of a lens barrel device according to an embodiment of the present invention.
A is shown, and FIG. 2 is a front view of the lens frame device. FIG. 3 is a perspective view of a movable lens frame unit incorporated in the lens frame device.

The lens barrel device of the present embodiment mainly includes a fixed frame 1
, A cam ring 2 fitted into the outer peripheral portion of the fixed frame 1 and supported rotatably, and a movable lens frame driven by the cam ring 2 to move forward and backward. The movable lens frame holds the second lens group 12, holds the second lens frame 4 supported by the fixed frame 1 so as to be able to advance and retreat in the direction of the optical axis O, and the first lens group 11. A first lens frame 3, which is a frame member supported by the two lens frames 4 so as to be able to advance and retreat in the optical axis O direction, and fixed to the second lens frame 4, so that the first lens frame 3 is slidable in the optical axis O direction. And a guide shaft 5 and a guide shaft 6 which are linear support members for guiding the guide shaft.

The fixed frame 1 has three linear guide grooves 1a.
And a straight escape groove 1b and an adjusting through hole 1c.

The cam ring 2 has a gear portion 2a on the outer periphery thereof,
Three oblique cam grooves 2b for driving the second lens frame 4 forward and backward, one oblique cam groove 2c for driving the first lens frame 3 forward and backward, and an adjustment through hole 2d are provided. I have.

A drive gear 23 driven via a gear train by a pinion 22 of a lens frame drive motor (M) 21 meshes with a gear portion 2a on the outer periphery of the cam ring 2.
The amount of rotation of the drive motor 21 can be detected by an output pulse of a PI (photo interrupter) 25 obtained through a slit plate 24 fixed to a motor shaft.

The second lens frame 4 has three cam followers 8 fitted in the cam groove 2b of the cam ring on the outer peripheral portion thereof,
Shaft support holes 4a and 4b, which are two shaft support holes arranged symmetrically with respect to the optical axis O, and an adjusting hole 4c arranged on a side surface of the shaft support hole 4b are provided. The shaft support hole 4a is a support hole having a loose fit with respect to the guide shaft 5, and the shaft support hole 4b is a support shaft portion 6b of the guide shaft 6.
Is a support hole for precision fitting (fitting with a very small gap). The adjusting screw hole 4c is a screw hole into which a set screw 13 which is one of the adjusting means is screwed.

The first lens frame 3 has one cam follower 7, a shaft hole 3a arranged at a position facing the shaft support holes 4a and 4b of the second lens frame 4, and a U-shaped guide portion. Notch 3b is provided. The cam follower 7 is a cam follower that penetrates through the clearance groove 1b of the fixed frame 1 with play, and is slidably fitted into the cam groove 2c of the cam ring 2. The shaft hole 3a is a shaft hole in which the guide shaft 5 can slide in a precision fitting state, and the cutout 3b is a cutout in which the guide shaft 5 can slide on the slide shaft 6a of the guide shaft 6. .

The guide shaft 6 comprises a sliding shaft portion 6a fitted into the notch 3b of the first lens frame 3 and a support shaft portion 6b fitted into the shaft supporting hole 4b of the second lens frame 4. A slot 6c for tool adjustment is provided at the tip of the driving shaft 6a.

The sliding shaft portion 6a has an elliptical cross-sectional shape having a non-circular cross-sectional shape as shown in an enlarged view of a fitting state of the notch portion and the sliding shaft portion in FIG. When the support 6 is rotated about the support shaft 6b, the width in the X direction orthogonal to the optical axis O (see FIG. 4) changes symmetrically with respect to the axis. The change range of the width dimension is a range that covers the width of the notch 3b of the first lens frame 3. The support shaft 6b has a circular cross-section coaxial with the axis of the slide shaft 6a. The cross section of the sliding shaft portion 6a may be an elliptical cross section or the like in addition to the elliptical cross section.

FIG. 5 is an electric circuit diagram of a lens barrel advance / retreat drive unit of the camera in which the lens barrel device of the present embodiment is incorporated. The electric circuit includes a power supply battery 31, a CPU 32 for controlling the entire camera, a motor driver circuit 33 controlled by the CPU 32, the drive motor 24 for driving the lens frame advanced and retracted driven by the motor driver circuit, Motor 2
4 includes the PI 25 for detecting the rotation of the PI 4, a transistor 36 and a resistor 37 for driving the PI 25, and a load resistor 38 for the PI 25.

When the movable lens frame is assembled and adjusted, an ammeter (A) 39 is connected to the output line of the battery 31 for measuring the lens frame drive current. At the time of the above adjustment, the pulse output signal of the PI 25 is extracted from the terminals 41 and 42 at both ends of the load resistor 38, and the rotation state of the drive motor 24 is detected.

Next, a description will be given of a procedure for assembling and adjusting the movable lens frame portion in the lens frame device of the present embodiment having the above-described configuration. In the movable lens frame portion, the second lens frame 4
The guide shaft 5 mounted on the second lens frame 4 is bonded and fixed to the second lens frame 4 so as to be parallel to the optical axis O. Further, the guide shaft 6 is connected to the shaft support hole 4b of the second lens frame 4 by the shaft support hole 4b. By changing the rotation position, the first lens frame 3 that is slidably fitted is formed.
It is necessary to adjust and fix the gap so as to have a small gap suitable for sliding with respect to the notch 3b.

First, when adjusting the movable lens frame unit alone,
The guide shaft 5 is inserted into the shaft support hole 4a of the second lens frame 4 with play, and is held in a state parallel to the optical axis O using a centering jig and fixed by bonding.

Then, the support shaft portion 6b of the guide shaft 6 is inserted into the shaft support hole 4b of the second lens frame 4, and is temporarily fixed by the set screw 13. The first lens frame 3 is slidably mounted on the second lens frame 4 by inserting the guide shafts 5 and 6 into the shaft holes 3a and the notches 3b.

In the state where the first lens frame 3 is attached, the notch 3b and the sliding shaft 6 of the guide shaft 6 are rotated while the guide shaft 6 is rotated by a driver or the like at the slot 6c.
The gap a is checked to determine a state in which the gap is minimized, or a state in which an appropriate gap is obtained in which a good driving state can be obtained. In this state, the set screw 13 is tightened to fix the guide shaft 6 to the second lens frame 4. Thereafter, the adjusted movable lens frame portion is inserted into the fixed frame 1 and the cam ring 2, and assembly and adjustment are completed.

Next, a description will be given of a case where the guide shaft is adjusted with the movable lens frame portion incorporated in the fixed frame 1 and the cam ring 2. First, the guide shaft 5 is bonded to the second lens frame 4 by the above-described method. Then, the guide shaft 6 is temporarily fixed. The first lens frame 3 is connected to the guide shaft 5
6 so that it can move forward and backward. The movable lens frame is inserted into the fixed frame 1 on which the cam ring 2 is mounted. In this inserted state, the cam follower 8 is fixed to the outer periphery of the second lens frame 4 by passing through the cam ring, the cam groove 2b of the fixed frame, and the straight groove 1a.
Further, the cam follower 7 is connected to the cam ring, the cam groove 2c of the fixed frame,
The escape groove 1b is inserted and fixed to the first lens frame 3 to temporarily assemble.

A drive gear 23 driven by a drive motor 21 is meshed with the gear 2a of the cam ring of the lens frame device in the temporarily assembled state, and the CPU 3 shown in the electric circuit diagram of FIG.
2, the drive motor 21 is driven under a constant drive condition such as a drive voltage, so that the first lens frame 3 can be driven forward and backward via the cam ring 2. The electric circuit and the like may be dedicated to adjustment, or may be a circuit or the like incorporated in an actual camera.

While the first lens frame 3 is driven forward and backward in the above-described state, the slot 6c is turned by a tool to rotate the guide shaft 6, and the notch 3b of the first lens frame 3 and the guide shaft 6 are rotated. Is gradually changed.
The rotational speed of the drive motor 21 when the gap is changed (corresponding to the forward / backward drive speed of the first lens frame 3) is PI2
Monitor by the output pulse of No. 5. Then, it is determined that a state in which an appropriate value that does not decrease the rotation speed is obtained is a proper state in which the clearance of the sliding shaft portion 6a is smaller, and
The guide shaft 6 is fixed to the second lens frame 4 by the set screw 13 at the rotation position at that time.

In the above-described method of adjusting the guide shaft in a state where the movable lens frame portion is incorporated in the fixed frame 1 and the cam ring 2, the PI
The output pulse of 25 was detected and adjusted, but as another method, an ammeter (A) 39 was connected to the power supply line as shown in FIG.
Is inserted, and the degree of the rotational load of the drive motor 21 is monitored by the current to check the advance / retreat driving state of the first lens frame 3 and to set an appropriate clearance of the sliding shaft portion 6a. Is also possible.

According to the lens frame device of the present invention described above, a guide shaft having a non-circular cross section is applied, and the play with the notch can be adjusted to the minimum by the rotation position. A good driving state with little backlash can be obtained, and the configuration is simple, the number of components is small, and the occupied space does not increase.

[0028]

As described above, according to the lens frame device of the present invention, a good driving state with little backlash can be obtained, and the structure is simple, the number of components is small, and the occupied space is increased. Absent.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view along an optical axis of a lens barrel device according to an embodiment of the present invention.

FIG. 2 is a front view of the lens barrel device of the embodiment.

FIG. 3 is a perspective view of a movable lens frame unit incorporated in the lens frame device of the embodiment.

FIG. 4 is an enlarged view showing a fitting state of a notch portion of a first lens frame and a sliding shaft portion constituting a movable lens frame portion of the lens frame device of the embodiment.

FIG. 5 is an electric circuit diagram of a lens frame advance / retreat drive unit of the camera in which the lens frame device of the embodiment is incorporated.

[Explanation of symbols]

 3 First lens frame (frame member) 3b Notched portion (guided portion) 6 Guide shaft (straight support member, adjusting means) 6c Slot portion (adjusting means) 13 Set screw (Adjustment means) 21... Drive motor (drive means)

Claims (3)

[Claims] 1. A frame member; a linear support member having a non-circular cross-sectional shape for supporting the frame member so as to be capable of linearly moving; and a guided portion formed on the frame member, engaging with the linear support member, and slidingly in contact therewith. And a lens frame device, comprising: rotating the linear support member around its own axis to adjust the gap between the guided portion and the linear support member. . 2. A frame member; a linear support member having a non-circular cross-sectional shape for supporting the frame member so as to be able to move linearly; and a guided portion formed on the frame member, engaging with the linear support member, and slidingly contacting. And a driving means for moving the frame member forward and backward in the axial direction of the rectilinear support member, and rotating the rectilinear support member around its own axis so that the guided portion and the rectilinear support member Characterized in that the gap between the lens frame and the lens can be adjusted. 3. A frame member; a linear support member having a non-circular cross-sectional shape for supporting the frame member so as to be able to move linearly; and a guided portion formed on the frame member, engaged with the linear support member, and slidably in contact therewith. Driving means for moving the frame member in the axial direction of the linear support member; and rotating the linear support member around its own axis.
Adjusting means for adjusting an air gap between the guided portion and the straight-moving support member.