JP6588609B2 - Optical device - Google Patents

Description

  The present invention relates to an optical device.

  When the cam ring formed with the cam groove rotates with respect to the fixed cylinder formed with the rectilinear groove, the lens unit interlocked with the rectilinear groove and the cam follower engaged with the cam groove moves in the optical axis direction. A technique for an optical device that performs zooming or focusing has been proposed (see Patent Document 1).

  Patent Document 1 aims to provide an optical device that can smoothly perform zooming or focusing without affecting the optical performance regardless of the angle of the cam groove with respect to the rectilinear groove. In order to achieve the object, the first lens barrel that holds the optical element and moves in the optical axis direction of the optical element, and the first lens barrel moves with the movement of the first lens barrel. Cam having a second lens barrel that moves in the same direction as the first direction and first and second cam grooves that displace the first and second cam followers connected to the first and second lens barrels in the optical axis direction A ring, a fixed cylinder provided with first and second rectilinear grooves for guiding the first and second cam followers in the optical axis direction, and a direction in which the first cam follower and the second cam follower intersect with the optical axis direction, respectively. The structure which has the urging | biasing member to urge is employ | adopted.

JP 2013-257369 A

  In the technique of Patent Document 1, the component member is urged in a direction intersecting the optical axis direction by using the urging member. Employing a configuration using such a biasing member may complicate the configuration of the optical device and may cause problems such as durability of the biasing member.

  Accordingly, an object of the present invention is to provide an optical device that can suppress the influence on the optical performance when the lens unit moves in the optical axis direction with a simple configuration.

In order to achieve the above object, an optical device according to the present invention includes a fixed cylinder having a rectilinear groove, a cam ring having a cam groove, a lens unit for holding a lens, and a rectilinear groove provided in the lens unit. And an optical device having a cam follower that engages with the cam groove, each lens unit includes two lens units, and each lens unit includes an auxiliary cam follower that engages with the rectilinear groove and does not engage with the cam groove. Each auxiliary cam follower of the unit is disposed on the side of each lens unit sandwiching each cam follower. It is characterized by that.
Here, the cam ring may be rotatable around the optical axis of the optical device, and the fixed cylinder may be fixed with respect to the rotation around the optical axis.
Further, the cam follower and the auxiliary cam follower may be cylindrical.

  In order to achieve the above object, an optical device according to the present invention includes a fixed cylinder or cam ring in which a cam groove is formed with respect to one of a fixed cylinder or cam ring in which a rectilinear groove extending in a direction parallel to the optical axis is formed. The lens unit that moves in conjunction with the cam follower that engages with the rectilinear groove and the cam groove is moved by rotating the other one different from the cam groove, and the lens unit is inserted into the cam follower and the rectilinear groove and is not inserted into the cam groove. Fixed with an auxiliary cam follower.

  According to the present invention, it is possible to provide an optical device that can suppress the influence on the optical performance when the lens unit is moved in the optical axis direction with a simple configuration.

It is a figure which shows the state of the cam follower engaged with the rectilinear groove and cam groove which comprise the optical apparatus which concerns on embodiment of this invention, and is a top view of the outer peripheral surface of the cam ring in which the cam groove was formed. It is an AA end view of FIG.

  Hereinafter, an optical device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a state of a cam follower that engages with a rectilinear groove and a cam groove constituting an optical device according to an embodiment of the present invention, and is a plan view of an outer peripheral surface of a cam ring in which the cam groove is formed. . FIG. 2 is an AA end view of FIG.

  The optical device 1 has a rectilinear groove 2 extending in a direction parallel to the optical axis L, and has a cylindrical fixed cylinder 3 having the optical axis L as a center line. A cylindrical cam ring 5 having the optical axis L in which the cam groove 4 is formed as a center line rotates with respect to the fixed cylinder 3 with the center line as a rotation axis. Here, the cam ring 5 is disposed so as to cover the outer peripheral surface of the fixed cylinder 3 from the outside. By this rotation, the lens unit 7 fixed and interlocked with the cam follower 6 that engages with the rectilinear groove 2 and the cam groove 4 moves in the optical axis L direction. The lens unit 7 is fixed and interlocked with the cam follower 6, and is further fixed and interlocked with the auxiliary cam follower 8 that is inserted into the rectilinear groove 2 and not inserted into the cam groove 4.

  As shown in FIG. 2, the lens unit 7 includes a holding member 9 and a lens 10. The holding member 9 holds the cam follower 6, the auxiliary cam follower 8, and the lens 10. As the cam follower 6 moves, the auxiliary cam follower 8, the holding member 9 and the lens 10 (that is, the lens unit 7) move in the same direction and the same distance.

  The rectilinear groove 2 and the cam groove 4 intersect at an angle of θ = 45 ° shown in FIG. When the front side of the cam ring 5 shown in FIG. 1 is rotated in the M direction while fixing the fixed cylinder 3, the lens unit 7 is moved in the M ′ direction by the cam operation. At that time, the point where the fixed cylinder 3 is most strongly in contact with the cam follower 6 is a point 11 where the rectilinear groove 2 shown in FIG. 1 presses the cam follower 6. Further, the place where the cam ring 5 abuts the cam follower 6 most strongly is a point 12 where the cam groove 4 shown in FIG. 1 presses the cam follower 6.

  As described above, when the cam follower 6 receives forces from two directions when the point 11 and the point 12 are close (concentrated) on the lower left side shown in FIG. 1, the lens unit 7 is fixed and interlocked with the cam follower 6. Receives a force such that the optical axis L tilts in the direction of the arrow S in FIG. 1, and tries to tilt, for example, as the optical axis L ′. Then, there arises a problem of influence on optical performance when the lens unit 7 moves in the direction of the optical axis L. This tendency becomes larger as the angle of θ shown in FIG. 1 approaches 0 °, since the points 11 and 12 are closer to each other.

  However, the presence of the auxiliary cam follower 8 can hold the force applied to the lens unit 7 so that the optical axis L tends to tilt in the direction of the arrow S. Here, unlike the cam follower 6, the auxiliary cam follower 8 that is not inserted into the cam groove 4 is inserted into the rectilinear groove 2 without being affected by the contact of the point 12. The auxiliary cam follower 8 is fixed and interlocked with the lens unit 7. Then, the auxiliary cam follower 8 tries to maintain the rectilinearity along the rectilinear groove 2 against the force that the lens unit 7 tends to tilt in the direction of the arrow S. For this reason, the posture of the lens unit 7 along the rectilinear groove 2 is easily maintained.

  Further, due to the presence of the auxiliary cam follower 8, when the fixed cylinder 3 is fixed and the front side of the cam ring 5 shown in FIG. 1 is rotated in the M direction, the straight groove 2 pushes the cam follower 6. In addition to the point 11 to be pressed, a point 13 to which the rectilinear groove 2 presses the auxiliary cam follower 8 is also added. Therefore, the location where the fixed cylinder 3 is pressed is increased, and the pressing force per location is reduced. Further, the presence of the auxiliary cam follower 8 disperses the forces from the two directions received by the cam follower 6 without concentrating them, so that the force applied to the lens unit 7 so that the optical axis L is inclined in the direction of the arrow S in FIG. Is less likely to occur.

  As described above, the optical device 1 according to the embodiment of the present invention does not use an urging member or the like, and can be used when the lens unit 7 is moved in the direction of the optical axis L with a simple configuration by devising an existing member. The influence on the optical performance can be suppressed.

  The above-described optical device 1 according to the embodiment of the present invention is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. It is.

  For example, as shown in FIGS. 1 and 2, the number of auxiliary cam followers 8 is one, but may be two or more. As shown in FIGS. 1 and 2, the auxiliary cam follower 8 and the cam follower 6 are arranged adjacent to each other, but may be arranged apart from each other along the rectilinear groove 2. If the auxiliary cam follower 8 and the cam follower 6 are arranged apart from each other, the force from the two directions received by the cam follower 6 can be more dispersed, and the force applied to the lens unit 7 so that the optical axis L is inclined in the direction of the arrow S. The effect of making it difficult to occur increases. However, from the viewpoint of downsizing the optical device 1, it is preferable that the auxiliary cam follower 8 and the cam follower 6 be close to each other.

  Further, the rectilinear groove 2 and the cam groove 4 intersect at an angle of θ = 45 °. However, the value of θ may be any value. The optical device 1 according to the embodiment of the present invention is particularly effective when it has a portion of 45 ° or less where the inclination of the optical axis L is concerned as the value of θ.

  The cam ring 5 is arranged so as to cover the outer peripheral surface of the fixed cylinder 3 from the outside. However, the fixed cylinder 3 may be arranged so as to cover the outer peripheral surface of the cam ring 5 from the outside. Further, the rectilinear groove 2 may be formed in the cam ring 5 instead of the fixed cylinder 3, and the cam groove 4 may be formed in the fixed cylinder 3 instead of the cam ring 5.

  Further, the optical apparatus 1 according to the embodiment of the present invention rotates the cam ring 5 in the M direction from the front side shown in FIG. 'Moving in the direction. However, by rotating the fixed cylinder 3 from the near side shown in FIG. 1 in the direction opposite to the M direction while fixing the cam ring 5, the lens unit 7 is moved in the M ′ direction by the cam operation. Also good.

DESCRIPTION OF SYMBOLS 1 Optical apparatus 2 Straight advance groove | channel 3 Fixed cylinder 4 Cam groove 5 Cam ring 6 Cam follower 7 Lens unit 8 Auxiliary cam follower L Optical axis

Claims (3)

An optical device having a fixed cylinder having a rectilinear groove, a cam ring having a cam groove, a lens unit for holding a lens, and a cam follower provided in the lens unit and engaging with the rectilinear groove and the cam groove. In the device
Having two lens units,
Each lens unit includes an auxiliary cam follower that engages with the rectilinear groove and does not engage with the cam groove.
The auxiliary cam followers of the lens units are arranged on the side of the lens units sandwiching the cam followers,
The auxiliary cam followers of the lens units are not adjacent to the cam followers, and are arranged apart from the cam followers along the straight groove.
An optical device. The optical device according to claim 1.
The cam ring is rotatable around the optical axis of the optical device,
The fixed cylinder is fixed with respect to rotation around the optical axis;
An optical device. The optical device according to claim 1 or 2,
The cam follower and the auxiliary cam follower are cylindrical.
An optical device.