JPH0524888Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a lens drive mechanism that engages and disengages a drive system in conjunction with a lens locking member of an autofocus camera with interchangeable lenses.

(Prior Art and Problems to be Solved) A focus adjustment device is provided on the camera body side, and the lens barrel of an interchangeable lens coupled to the camera is connected to the focus adjustment device, and the lens is attached from the camera side. A camera that performs automatic focus adjustment by driving the camera (auto focus camera) has been proposed.

The lens drive mechanism of the above-mentioned autofocus camera with interchangeable lenses will be explained with reference to FIG. The rotation of the motor installed inside the camera body is decelerated by a reduction gear train and transmitted to the output gear on the body side, and when the interchangeable lens is connected to the body, the output of the output gear is sent to the input on the lens side via the connecting gear 6. It is input to the gear 5, rotates the lens pinion 4 provided integrally with the input gear 5, and is further connected to the distance ring gear 3 that meshes with the lens pinion 4, and drives the distance ring 2 to move the lens 1 forward or backward. It is configured as follows.

In addition, as a structure for attaching a camera body and an interchangeable lens, a bayonet mount is generally used in which the body and lens are mounted in the form of a mount, and the camera body and the lens can be attached and detached at an attachment/detachment angle θ.

When attaching an interchangeable lens to an autofocus camera having such a lens drive mechanism, the third
As shown in the figure, the flange surface of the body and the flange surface of the lens are brought into contact, and the lens is rotated to the right or left (in the case of FIG. 3, clockwise by an angle θ) and mounted.

In the initial mounting position of the interchangeable lens, the input gear 5 on the lens side is at the position (I), and when the lens is turned clockwise, it comes into contact with the connecting gear 6 on the body side at the position (), and the input gear 5 on the lens side is at the position (I). The input gear 5 and the connection gear 6 begin to mesh from this position. It is necessary to further rotate the lens by Δθ until it is completely attached, and the input gear 5 and connecting gear 6
engage while rotating.

At this time, if the input gear 5 on the lens side does not rotate, the connecting gear 6 on the body side must mesh while rotating in the direction a.

Conversely, if the connecting gear 6 does not rotate, the input gear 5 on the lens side cannot mesh with the connecting gear 6 unless it rotates in the direction b.

Generally, it is possible to rotate the input gear 5 in the direction b on the interchangeable lens side, but when the lens is attached at the final end position of the lens helicoid, it is not possible to impart rotation in the direction b.

On the other hand, when trying to give rotation to the connecting gear 6 on the body side, the motor must be rotated by going back through the reduction gear train connected to the connecting gear 6, resulting in an excessive load and depending on the reduction ratio of the gear. Rotation as described above is impossible, and unless special measures are taken, the fourth
Interchangeable lenses cannot be attached or detached using the method shown in the figure.

On the other hand, in order to transmit the motor output from the camera body to the interchangeable lens and focus it, there is a device that connects the output member on the camera body side and the input member on the interchangeable lens side when the lens is attached, as disclosed in JP-A-55-120022. . This technology operates the lens attachment/detachment button,
The camera body side connecting portion is temporarily moved out, and when the lens attachment is completed, the camera body side connecting portion is advanced and connected to the lens side connecting portion. However, this technology lacks the technology to align both connecting parts, that is, the technology to rotate the interchangeable lens and lock it in a predetermined position, and the technology to completely connect both connecting parts in the axial direction. It was hot.

In addition, when attaching an interchangeable lens to a camera body, when the lens is rotated by a predetermined angle, a locking pin locks the interchangeable lens at the completed attachment position.
There is No. 29219. However, even when these prior art techniques are combined, there is still a problem in completely compensating for the connection between the camera body side output member and the lens side input member.

(Means for Solving the Problems) In view of the above-mentioned circumstances, the present invention provides a movable member that is biased in one direction by the first biasing device, and the lens locking member is attached to the movable member by the first biasing device. protrudes from the mount surface to lock the lens, and when the lens is mounted, the lens locking member is retracted from the mount surface against the urging force at the base of the lens. On the other hand, a connecting gear that moves in conjunction with the operation of the movable member while always meshing with the output gear that transmits the rotation of the motor, and that connects to the input gear on the interchangeable lens side is separated from the surface of the movable member for a predetermined period. The lens is rotatably supported by a second urging means in a direction away from the surface of the movable member and pivoted on the movable member, and the lens is rotated by a predetermined angle to lock the lens. The connecting gear is configured to return to the position where it is connected to the input gear in conjunction with the returning operation of the lens locking member.

(Example) The present invention will be described in more detail below with reference to the drawings and the like.

FIG. 1 is a perspective view showing an embodiment of the main parts of the lens drive mechanism of the present invention.

In this embodiment, a pin is provided on the flange surface of the mount base 7 to engage with a positioning groove on the flange surface on the lens mount side (not shown) at the final position of mounting the interchangeable lens. It is equipped with an interlocking mechanism that engages and disengages the When the interchangeable lens is aligned with the bayonet claw 7a and rotated in the lens installation direction, it is pushed against the flange surface of the lens mount, and the pin 8 is pressed against the mount base 7.
It is pushed in against the biasing force of spring 9 up to the flange surface of. The pin 8 is provided integrally with the connecting gear 6 via the receiving plate 11, and since the connecting gear 6 also retreats together with the pin 8, it moves in the axial direction with respect to the input gear 5 on the lens side, and the connecting gear 6 and the input gear 5 cannot mesh with each other.

At this time, since the output gear 10 meshing with the connecting gear 6 has a sufficiently wide tooth width, the meshing is not separated by the movement in the axial direction.

When the lens is further rotated in the mounting direction and a positioning groove (not shown) on the flange surface of the lens mount reaches the position of the pin 8, the pin 8 is urged by the spring 9 and moves forward to engage with the groove. As a result of the advancement of the shaft 12 driven by the pin 8, the connecting gear 6 meshes with the input gear 5, and the driving force from the motor can rotate the distance ring of the lens.

At this time, if the position of the input gear 5 in the rotation axis direction is not at the meshing position with the connecting gear 6, the input gear 5 and the connecting gear 6 will mesh with each other due to the drive of the motor or the (manual) rotation of the lens distance ring. The input gear 5 reaches the position of the connecting gear 6 due to the biasing force of the spring 9.
meshes with

FIG. 2 is a mechanical diagram showing details of the interlocking mechanism shown in FIG. 1.

The pin 8 and the shaft 12 of the connecting gear 6 are connected via the receiving plate 11.
are integrally provided, and the connecting gear 6 is connected to the shaft 12.
It is biased forward by a spring 13 pushed into the body, and is locked by a retaining ring 12a.

When the pin 8 moves back, the connecting gear 6 also moves back together, but even when the input gear 5 of the lens and the connecting gear 6 do not mesh, the pin 8 can be restored, and even in this case, the motor drive or the lens distance ring ( By rotation (by hand), the input gear 5 and the connecting gear 6 reach a meshing position, and are biased by the spring 13, so that the input gear 5 and the connecting gear 6 mesh.

The release button 14 is provided outside the camera body, and its base is fixed to the receiving plate 11. By pressing the release button 14 and disengaging the pin 8 from the groove, the release button 14 is rotated in the opposite direction to the lens mounting direction. The lens can be removed from the body.

(Effects) As described above in detail, the drive mechanism according to the present invention has a lens locking member on a movable member biased in one direction, which is constantly engaged with the output gear of the motor, and generates the driving force of the motor. A connecting gear is provided to transmit data to the input gear on the interchangeable lens side, and this connecting gear is biased in the direction of connecting to the input gear by the biasing means provided on the movable member, so that the positioning groove and pin There is no need to provide a large engagement margin for the axial movement of the lens 8, and the interchangeable lens can be positioned and the motor drive system can be completely connected with a small engagement margin.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an embodiment of the main parts of the lens drive mechanism of the present invention, Fig. 2 is a mechanical diagram showing details of the interlocking mechanism shown in Fig. 1, and Fig. 3 shows how to attach and detach an interchangeable lens. FIG. 4 is a perspective view showing a camera body and an interchangeable lens of an autofocus camera with interchangeable lenses. 1... Lens, 2... Distance ring, 3... Distance ring gear, 4... Lens pinion, 5... Input gear, 6
...Connection gear, 7...Mount base, 7a...
Bayonet claw, 8...pin, 9...spring, 10...
...output gear, 11...receiving plate, 12...shaft, 13...
...Spring, 14...Release button.

Claims (1)

[Claims for Utility Model Registration] Rotation of a motor provided within a camera body is transmitted to an output gear via a transmission mechanism, and when an interchangeable lens is coupled to the camera body, the driving force of the output gear is transferred to the exchanger. A movable member biased in one direction by a first biasing means; a movable member biased in one direction by a first biasing means; is provided, is biased in a protruding direction from the mount surface by the first biasing means, is retracted against the biasing force by the base of the interchangeable lens when the interchangeable lens is rotatably mounted, and is returned when coupled. a columnar lens locking member that locks the interchangeable lens; a connecting gear provided on the movable member such that it is energized and moves in conjunction with the operation of the movable member while always meshing with the output gear, and is capable of engaging and disengaging from the input gear at a location other than the mounting surface; and a release button provided on the movable member that is operated externally, and moves the connecting gear in a direction to disconnect from the input gear in conjunction with the retracting operation of the lens locking member, and the replacement A lens drive mechanism for an autofocus camera with interchangeable lenses, characterized in that the connection gear is returned to a connection position with the input gear in conjunction with the return operation of the locking member after the lens has been rotated by a predetermined angle.