JPH0352606B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a lens moving device in a lens barrel.

Structure of conventional example and its problems A conventional lens moving device is designed as shown in FIGS. 1 and 2. That is, a movable lens barrel 2 is slidably fitted around the outer periphery of a fixed lens barrel 1, and this movable lens barrel 2 holds a lens 3 at its end.
A pin 4 is implanted in the fixed lens barrel 1, and this pin 4 engages with a cam groove 5 provided in a side surface of the movable lens barrel 2 in a diagonal direction with respect to the optical axis X. When the movable lens barrel 2 is rotated, the movable lens barrel 2 moves in the optical axis X direction according to the cam groove 5. The conventional lens moving device configured as described above eliminates play in the optical axis X direction of the movable lens barrel 2 with respect to the fixed lens barrel 1 by using the cam groove 5.
This is absorbed by improving the cutting accuracy of the groove width and the outer diameter of the pin 4. Therefore, the cam groove 5
If the groove width is formed by plastic molding or the like, there is a problem in that the accuracy of the groove width becomes poor and the backlash in the optical axis X direction becomes large.

Purpose of the Invention The present invention solves the above-mentioned drawbacks of the conventional technology. Even when constructed using plastic molding, a mold with a simple structure can be used, and even if the precision of the groove width of the guide groove is poor, play in the optical axis direction can be avoided. It is an object of the present invention to provide a lens moving device that can prevent such movement.

Structure of the Invention In order to achieve the above object, the lens moving device of the present invention includes a first cylindrical body having a guide groove formed in a direction oblique to the optical axis direction and having a substantially parallel cross-sectional shape and passing through the first cylindrical body. an engaging member that is guided along the guide groove and has a trapezoidal cross-sectional shape in a direction perpendicular to the longitudinal direction of the guide groove and is engageable with the guide groove at an opposing slope thereof; a second cylindrical body that is fitted into the body to hold the engaging member and move relative to the first cylindrical body; and between the engaging member and the second cylindrical body. The guide groove of the first cylindrical body includes a biasing means that is interposed and presses the engaging member against the guide groove to engage the opposing slope of the engaging member with the guide groove. The engaging member of the second cylindrical body has a trapezoidal cross section, and this engaging member is constantly pressed against the guide groove by a biasing means and engaged with the opposing slope, thereby preventing backlash in the optical axis direction. It is.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 3 and 4, 11 is a fixed lens barrel;
A movable lens barrel 12 is slidably fitted onto the fixed lens barrel 11, and a movable lens barrel 13 is held in a lens holding portion 14 formed on the inner circumferential surface of one end of the movable lens barrel 12, and held by a lens holding frame 15. A fixed lens, 16 is a long hole-shaped cam groove formed on the side surface of the movable lens barrel 12 in a direction oblique to the optical axis X direction, and 17 is a recess provided in a part of the outer periphery of the fixed lens barrel 11 A shaft 18 facing into the cam groove 16 of the movable lens barrel 12 is implanted in this recess 17 . 19 has a truncated conical shape, and the diameter (d) of the small diameter portion is smaller than the groove width (W) of the cam groove 16, and the diameter (D) of the large diameter portion is set larger than the groove width (W). The cam follower is inserted into the shaft 18 of the recess 17 from the large diameter side and is loosely fitted to the shaft 18 so as to be able to slide. 20 is cam follower 1
A leaf spring inserted into the shaft 18 together with the leaf spring 9 and located in the recess 17 presses and biases the cam follower 19 against the cam groove 16 from below, and the opposing slope of the cam follower 19 is engaged with the cam groove 16 by the biasing force. There is.
Although the cam follower 19 has a circular cross section, the cam follower 19 is not limited to this, as long as the cross section perpendicular to the longitudinal direction of the cam groove 16 is trapezoidal.

In the above configuration, when the movable lens barrel 12 is rotated relative to the fixed lens barrel 11, the cam groove 16 moves relative to the cam follower 19, which causes the movable lens barrel 12 to move relative to the cam follower 19.
moves in the optical axis X direction while rotating. At this time, even if the cam groove 16 is made of plastic molding or the like and its groove width (W) has poor precision, the cam follower 19 that engages with the cam groove 16 at the opposing slope will be moved by the leaf spring 20. Since the movable lens barrel 12 is always pressed against the cam groove 16, the optical axis
There is no directional wobble.

In addition, in the embodiment described above, the inner lens barrel 1
1 is fixed and the outer lens barrel 12 is movable, but in the opposite configuration, the inner lens barrel 11 is movable, the outer lens barrel 12 is fixed, and the lens 13 is attached to the inner lens barrel 11. Needless to say, it is okay to keep it.

Effects of the Invention As described above, according to the present invention, since the first cylindrical body is formed with a penetrating guide groove with a substantially parallel cross section, plastic molding can be performed using a mold with a simple structure. It can be easily produced in a short time. In addition, since the engaging member that engages with the guide groove on the opposing slope is always pressed against the guide groove by the biasing means, play in the optical axis direction is prevented even if the groove width of the guide groove is inaccurate. can, therefore,
Since the guide groove and the engaging member can be processed by plastic molding, it is possible to provide a lens moving device that is inexpensive and highly mass-producible.

[Brief explanation of drawings]

Figure 1 is a half longitudinal sectional view of the conventional example, and Figure 2 is the first half of the conventional example.
FIG. 3 is a half longitudinal sectional view showing an embodiment of the present invention, and FIG. 4 is a plan view of the main portion in FIG. 3. 11... fixed lens barrel, 12... movable lens barrel, 13...
... Lens, 16... Cam groove, 19... Cam follower, 20... Leaf spring, X... Optical axis.

Claims (1)

[Claims] 1. A first cylindrical body having a guide groove formed obliquely with respect to the optical axis direction and having a substantially parallel cross-sectional shape and passing through the side surface, and a first cylindrical body guided along the guide groove and extending in the longitudinal direction of the guide groove. an engaging member having a trapezoidal cross-sectional shape in a direction perpendicular to the first cylinder and capable of engaging with the guide groove at an opposite slope thereof; A second cylindrical body that moves relatively to the first cylindrical body, and is interposed between the engaging member and the second cylindrical body, and presses the engaging member into the guide groove. A lens moving device including biasing means for engaging opposing slopes of the engaging member with the guide groove.