JPS6339682Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lens drive mechanism that connects and disconnects a drive system in conjunction with a lens locking member of an autofocus camera with interchangeable lenses.

A camera that performs automatic focus adjustment by providing a focus adjustment device on the camera body side, connecting the lens barrel of an interchangeable lens connected to the camera to the focus adjustment device, and driving the lens from the camera side. Autofocus 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 that has such a lens drive mechanism, the second
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. 2, 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 (), and when the lens is rotated 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 (). The input gear 5 and the connection gear 6 begin to mesh from then on. 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 direction b on the interchangeable lens side, but when the lens is mounted at the final end of the lens helicoid, it is not possible to rotate the input gear 5 in 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 first
Interchangeable lenses cannot be attached or detached using the method shown in the figure.

An object of the present invention is to provide a lens drive mechanism for an autofocus camera that solves the above-mentioned problems and allows easy attachment and detachment of the lens.

In order to achieve the above object, the lens drive mechanism of the autofocus camera with interchangeable lenses according to the present invention transmits the rotation of the motor provided in the camera body to the output gear via the transmission mechanism, and drives the interchangeable lens. In an autofocus camera with an interchangeable lens that moves the lens of the interchangeable lens forward or backward by coupling the output gear to the input gear on the lens side when coupled to the body, when the interchangeable lens is rotatably attached or detached, the lens a lens locking member that is retracted by the base immediately before the end of the connection, returns to lock the lens during the connection, and is temporarily retracted when the lens is released; and a connecting gear capable of disconnecting and disconnecting the output gear and the input gear. and an interlocking mechanism that moves the connecting gear in a direction in which the input/output gear is disengaged in conjunction with the retracting operation of the locking member.

The present invention will be explained in more detail below with reference to the drawings and the like.

FIG. 3 is a perspective view showing a first embodiment of the lens drive mechanism of the present invention.

In the first embodiment, a pin is provided on the flange surface of the mount base to engage with a positioning groove on the flange surface on the lens mount side at the final position of mounting the interchangeable lens, and the gear is moved by the axial movement of the shaft that interlocks with this pin. It is equipped with an interlocking mechanism for engaging and disengaging. When the interchangeable lens is aligned with the bayonet pawl and rotated in the lens mounting direction, it is pushed by the flange surface of the lens mount, and the pin 8 is pushed against the biasing force of the spring 9 to the flange surface of the mount base. 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 the positioning groove 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. Axis 1 driven by pin 8
2 moves forward, 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 rotational 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 driving of the motor or rotation of the lens distance ring (by hand). When the input gear 5 reaches the position , the input gear 5 meshes with the connecting gear 6 due to the urging force of the spring 9.

FIG. 4 is a mechanical diagram showing a modification of the interlocking mechanism of the first embodiment of the present invention.

In the first embodiment, it is necessary to provide a certain degree of engagement between the groove on the flange surface of the lens and the axial movement of the pin 8, but as shown in FIG. The engagement distance by the pin 8 can be small.

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 inserted 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.

Although this embodiment shows an example in which the pin 8 is also used as a lens locking pin, the pin 8 may be provided separately from the lens locking means.

FIG. 5 is a perspective view showing a second embodiment of the lens drive mechanism of the present invention.

In the second embodiment, a notch for positioning the lens is provided in the bayonet pawl of the lens, and a bayonet mount of the type that locks a lever on the body side is used to interlock with this lever to mesh the connecting gear 6 and input gear 5. The figure shows the case of connecting and disconnecting.

In FIG. 5, the bayonet pawl of the lens is shown moved in the axial direction.

The shaft 22 of the connecting gear 6 and the shaft of the output gear 10 that meshes with this gear 6 are connected by a receiving plate 21.
The connecting gear 6 is rotatable about the axis of the output gear 10.

The tip of one arm of the bell crank 23 has a notch 2
3a, the shaft 22 of the connecting gear 6 is held between the notch 23a, and a pin 23b is fixed to the other arm by caulking. Further, the bell crank 23 is biased clockwise in FIG.

The lock lever 28 is biased counterclockwise about a shaft 28c by a spring 29, and the final end of its rotation is restricted by a stopper pin 27.

A lock portion 28a of the lock lever 28 engages with a bayonet pawl on the lens side, and the other end extends downward and engages with a pin 23b of the bell crank 23. When attaching an interchangeable lens, the displacement of the lock lever 28 follows the engaging bayonet pawl of the lock portion 28a, and when it is locked in the notch of the bayonet pawl (the state shown in Fig. 5), it is almost at the position before the lens is attached. will be in the same position as

In the above configuration, when an interchangeable lens is attached, the lock portion 28a of the lock lever 28 comes into contact with the bayonet pawl on the lens side during (or at the beginning) of rotation through the attachment/detachment angle θ, and the lock lever 28 begins to be displaced. This displacement causes the input gear 5 to move to the connecting gear 6.
2, the locking portion 28b of the lock lever 28 and the pin 23b of the bell crank 23 engage, and the connecting gear 6 is centered on the axis of the output gear 10. to separate the connecting gear 6 from the input gear 5. When the lock lever 28 reaches the position of the attachment/detachment angle θ (the input gear 5 is in the position shown in FIG. Since the engagement with the pin 23b is released, the bell crank 23 is released from the spring 2.
5 rotates clockwise, connecting gear 6
is rotated counterclockwise while meshing with the output gear 10, and the bell crank 23 engages with the stopper pin 2.
4, the connecting gear 6 and the input gear 5 mesh with each other with a regular distance between their axes. At this time as well, input gear 5
Even if the teeth of the connecting gear 6 and the connecting gear 6 do not mesh with each other, they can be brought to the meshing position by driving the motor or rotating the distance ring of the lens (by hand).

Furthermore, various modifications can be made without departing from the spirit of the invention.

For example, the stopper pin 25 may act on the receiving plate 21, and a gap is provided between the locking portion 28b of the lock lever 28 and the pin 23b of the bell crank 23 when the lens is attached.
The locking portion 28b of the lock lever 28 is divided into two parts and biased together by a spring so that the locking portion 28a and the locking portion 28b of the lock lever 28 are displaced when excessive force is applied. If configured, the gap is not necessary. Furthermore, the method of converting the displacement of the lock lever 28 into the displacement of the output gear is not via the bell crank 23 shown in FIG. 5, but it is also possible to provide an intermediate lever due to space constraints.

Although the lock lever 28 utilizes displacement due to engagement with a notch in the bayonet on the lens side, a transmission means may be used in place of the lock lever 28.

As described in detail above, according to the present invention, since an interlocking mechanism is provided that disconnects the transmission system at the final mounting position of the interchangeable lens, it is possible to realize a lens drive mechanism for an autofocus camera in which the lens can be easily attached and detached.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing the camera body and interchangeable lens of an autofocus camera with interchangeable lenses, Figure 2 is an explanatory diagram to explain how to attach and detach the interchangeable lens, and Figure 3 is the lens drive of the present invention. FIG. 4 is a perspective view showing the first embodiment of the mechanism.
FIG. 5 is a perspective view showing a second embodiment of the lens drive mechanism of the present invention. 1... Lens, 2... Distance ring, 3... Distance ring gear, 4
...Lens pinion, 5...Input gear, 6...Connection gear, 7...Bayonet pawl, 8...Pin, 9...Spring, 1
0... Output gear, 11... Receiving plate, 12... Shaft, 13... Spring, 14... Release button, 21... Receiving plate, 22... Shaft, 23
...bell crank, 24...stopper pin, 25...spring, 27...stopper pin, 28...lock lever,
29...Spring.

Claims (1)

[Scope of utility model registration request] The rotation of a motor provided inside the camera body is transmitted to an output gear via a transmission mechanism, and when an interchangeable lens is coupled to the body, the output gear is coupled to an input gear on the lens side, and the output gear is coupled to the input gear on the lens side. In an auto-focus camera with interchangeable lenses that moves forward and backward, when rotating the interchangeable lens to attach or detach it, the lens base retracts the lens just before the connection is completed, returns to lock the lens when it is connected, and when detaching the lens. A lens locking member that is temporarily retracted, a connecting gear that can disconnect and disconnect the output gear and the input gear, and a direction in which the connecting gear is linked to the retracting operation of the locking member to uncouple the input and output gears. A lens drive mechanism for an autofocus camera with interchangeable lenses, characterized by comprising an interlocking mechanism for moving the lens.