JP2019219604A - Lens device - Google Patents

Abstract

To provide a lens device that changes a light-shielding state of a notch of a movable frame by a light-shielding member with a low cost and simple structure, and that shields harmful light from the notch of the lens movable frame according to a position of the movable frame.SOLUTION: A lens device having a plurality of mobility groups moving in an optical axis direction comprises: a first movable frame that holds a first optical member 1; and a second movable frame that holds a second optical member 2. A notch that lets a portion of the second movable frame out to the first movable frame is formed in the lens device. In the first movable frame, a light-shielding member 15 that shields the notch at a predetermined optical axis direction position is provided, and the light-shielding member has varying means that can vary at least one of a position and an attitude relative to the first movable frame by means of straight moving force due to optical axis direction movement of the second movable frame.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lens operating device, and more particularly, to light shielding in a lens barrel of a lens device.

  In a zoom lens apparatus including a variable power lens as a first lens and a correction lens as a second lens, it is necessary to increase the moving distance of the variable power lens in order to achieve high magnification. However, if an attempt is made to reduce the overall length of the zoom lens device while maintaining the photographing magnification to reduce the size, depending on the moving distance of the zoom lens, a moving frame holding the zoom lens and a moving frame holding the correction lens are required. And interfere. Therefore, the moving frame of the variable power lens and the correcting lens is provided with a notch at a portion where the moving frames interfere with each other, thereby avoiding interference with the moving frame of the other party. However, when the moving frames are separated from each other, unnecessary light (harmful light) enters from the notch portion of the moving frame, which causes deterioration in image quality and generation of ghost. Therefore, when the moving frames are separated from each other, it is necessary to shield the notch of the moving frame.

  In Patent Document 1, harmful light is provided by providing a light shielding member for shielding a notch of a variable power lens separately from a moving frame, and moving the light shielding member in the optical axis direction in conjunction with the position of the variable power lens in the optical axis direction. Is prevented.

  In Patent Literature 2, a light shielding member is held by a moving frame of a variable power lens, and a cam follower provided on the light shielding member engages with a cam groove formed in a cam cylinder that drives the moving frame, thereby rotating the cam cylinder. The light blocking member rotates around the optical axis in conjunction with the rotation of the notch, thereby changing the blocking state of the notch.

JP 2006-215394 A JP 2014-38213 A

  However, in Patent Documents 1 and 2 described above, it is necessary to form a cam groove different from that for driving the moving frame in the cam cylinder that drives the moving frame, which complicates the structure and further increases the component cost. I will.

  Therefore, an object of the present invention is to change a light blocking state of a notch of a moving frame by a light shielding member with a low cost and simple structure, and to shield harmful light from the notch of the moving frame according to a position of the moving frame. It is to provide a device.

  In order to achieve the above object, a lens device according to the present invention is a lens device having a plurality of moving groups that move in an optical axis direction, wherein a first moving frame holding a first optical member and a second optical member are provided. And a second moving frame for holding the first moving frame, wherein a notch is formed in the first moving frame to allow a part of the second moving frame to escape. A light-shielding member that shields the notch is provided, and the light-shielding member is at least one of a relative position and an attitude relative to the first moving frame by a linear force generated by movement of the second moving frame in the optical axis direction. It is characterized by having a variation means capable of changing one.

  ADVANTAGE OF THE INVENTION According to this invention, the lens apparatus which changes the light blocking state of the notch of a moving frame by a light-shielding member according to the position of a moving frame with a low cost and simple structure, and shields the harmful light from the notch of a moving frame is provided. Can be provided.

Sectional view when each moving frame of the lens device of the first embodiment is located at the wide-angle end. FIG. 4 is a perspective view of the lens device according to the first embodiment when each moving frame is positioned at a wide-angle end. Sectional view when each moving frame of the lens device of the first embodiment is located at the telephoto end. FIG. 4 is a perspective view of the lens device of the first embodiment when each moving frame is located at a telephoto end. Detailed view of the light shielding member of the first embodiment Sectional view when each moving frame of the lens device of the second embodiment is located at the wide-angle end. Sectional view when each moving frame of the lens device of the second embodiment is located at the telephoto end. FIG. 6 is a front view of a zoom lens moving unit of the lens apparatus according to the second embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(Example 1)
A lens device L1 according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2 show a cross-sectional view and a perspective view when the lens device L1 is located at the wide-angle end. 3 and 4 show a cross-sectional view and a perspective view when the lens device L1 is located at the telephoto end. FIG. 5 shows a detailed view of the light blocking member 15 provided on the moving frame 13.

  The mechanism of the zoom unit will be described with reference to FIG. The lens device L1 has a plurality of lens groups, and a focus lens group F and a relay lens group (not shown) are arranged before and after the zoom unit. The focus lens group F is provided movably along the optical axis direction P, and focus adjustment is performed by being driven by driving means (not shown). The variable power lens group (first optical member) 1 is held by a moving frame (first moving frame) 13, and the correction lens group (second optical member) 2 is held by a moving frame (second moving frame) 14. Is held. The cam tube 6 is provided with cam grooves 6a and 6b for driving the moving frames 13 and 14 in the optical axis direction P, and is provided rotatably around the cam shaft S. The fixed cylinder 7 has a not-shown rectilinear groove for guiding the moving frames 13 and 14 along the optical axis direction P. The moving frames 13 and 14 are formed with cam followers 13a and 14a that engage with the cam grooves 6a and 6b, and a plurality of cam followers 13b and 14b that engage with the rectilinear grooves. The moving frames 13 and 14 are moved along the optical axis direction P by rotating the cam tube 6 by a driving unit (not shown), and the magnification is changed by changing the lens interval.

  Next, the shielding of the notch 13c of the moving frame 13 will be described with reference to FIGS. Notches 13c and 14c are formed in the moving frames 13 and 14 in a range where the moving frames approach each other when the moving frames approach each other during zooming, thereby avoiding interference between the moving frames. are doing. As shown in FIG. 1, when the moving frames 13 and 14 are located at the wide-angle end, the light ray R1 that has reached the notch 13c of the moving frame 13 passes through the notch 13c like the light ray R2. The light ray R2 passes through the correction lens group 2 and reaches an image sensor (not shown), becomes harmful light, and lowers image quality. Therefore, when the moving frames are separated from each other as in the case of the wide-angle end shown in FIG. 1, the notch 13 c is shielded by the light blocking member 15 to prevent the incidence of harmful light. On the other hand, when the moving frames approach each other as in the telephoto end shown in FIG. 3, the notch 13c is opened to avoid interference between the light blocking member 15 and the moving frame 14. However, although the notch 13c is opened, a part of the moving frame 14 is inserted into the notch 13c, so that the light beam R1 reaching the notch 13c does not pass through the notch 13c. In this case, the image quality does not deteriorate.

  Next, the operation of the light blocking member 15 will be described. As shown in FIG. 5, the light shielding member 15 has a movable member 15 a that shields the cutout portion, and a support member 15 b that is fixed to the moving frame 13 with the screw 8. The movable member 15a and the support member 15b are connected by a rotating shaft 15c and a holding ring 15d, and the movable member 15a is rotatably mounted on the support member 15b around the rotating shaft 15c. The movable member 15a is urged in one direction by coil springs (urging means) 15e and 15f. The movable member 15a is provided with a buffering member 15g to reduce the collision noise when the moving frame 14 comes into contact with the movable member 15a.

  When the moving frames are separated from each other as shown in FIGS. 1 and 2, the movable member 15a is urged toward the moving frame 13 by the elastic force of the coil springs 15e and 15f, so that the notch 13c is hidden. Placed in Accordingly, the light ray R1 that reaches the notch 13c among the light rays that have passed through the focus lens group F is blocked by the movable member 15a and does not enter the correction lens group 2, so that the image quality does not deteriorate. On the other hand, when the moving frames approach each other as shown in FIGS. 3 and 4, the movable member 15a is pushed by a part of the moving frame 14 via the buffer member 15g, and the notch 13c of the moving frame 13 is opened. Is done.

  As described above, according to the present embodiment, the light-shielding state of the notch of the moving frame by the light-shielding member is changed according to the position of the moving frame with a low-cost and simple structure, and the harmful effect from the notch of the lens moving frame is obtained. A lens device for shielding light can be provided. Further, since the light shielding member is not provided as a separate moving group, harmful light can be shielded without increasing the size of the lens device.

(Example 2)
A lens apparatus L2 according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a cross-sectional view when the lens device L2 is located at the wide-angle end. FIG. 7 is a cross-sectional view when the lens device L2 is located at the telephoto end. FIG. 8 is a front view of a moving unit including the variable power lens unit 1. In describing the second embodiment, members that are the same as or similar to those in the first embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals, and description thereof is omitted.

  The mechanism of the zoom unit will be described with reference to FIG. The variable power lens group (first optical member) 1 is held by a moving frame (first moving frame) 23, and the correction lens group (second optical member) 2 is a moving frame (second moving frame) 24 Is held in. The moving frames 23 and 24 have cam followers 23a and 24a which engage with the cam grooves 6a and 6b, and a plurality of cam followers 23b and 24b (not shown) which engage with straight movement grooves (not shown) formed in the fixed cylinder 7. Is formed. The moving frames 23 and 24 are moved along the optical axis direction P by rotating the cam tube 6 by a driving unit (not shown), and the magnification is changed by changing the lens interval.

  The operation of the light shielding member 25 according to the second embodiment will be described. The light shielding member 25 is an iron disk that shields the notch 23 c of the moving frame 23, and the moving frame 23 is provided with a magnet 23 d at a position in contact with the light shielding member 25. The moving frame 24 is provided with a magnet 24d at a position in contact with the light shielding member 25. When the moving frames are separated from each other as shown in FIG. 6, the light shielding member 25 is fixed to the magnet 23d of the moving frame 23 and moves in the optical axis direction P integrally with the moving frame 23. Accordingly, the light ray R1 that reaches the cutout portion 23c of the light that has passed through the focus lens F is blocked by the light blocking member 25 and does not enter the correction lens group 2, so that the image quality does not deteriorate. On the other hand, when the moving frames approach each other as shown in FIG. 7, the light shielding member 25 contacts and is pressed by the magnet 24 d of the moving frame 24, so that the partner to be fixed is moved from the magnet 23 d of the moving frame 23 to the moving frame 24. To the magnet 24d. Thereby, the notch 23c of the moving frame 23 is opened.

  As described above, according to the second embodiment, since the support member, the coil spring, and the rotating shaft can be omitted as compared with the first embodiment, the number of parts can be further reduced. can get. In this embodiment, the light-shielding member itself is made of iron, which is a ferromagnetic material. However, even when the light-shielding member itself is not a ferromagnetic material, the same effect can be obtained by disposing the ferromagnetic material in the light-shielding member. can get. A similar effect can be obtained by disposing a magnet on the light shielding member and disposing an iron plate on the moving frame.

  According to each of the above embodiments, the light shielding state of the notch of the moving frame by the light shielding member is changed according to the position of the moving frame with a low-cost and simple structure to shield harmful light from the notch of the lens moving frame. A lens device can be provided.

L1, L2 Lens device 1 Variable power lens group (first optical member)
2 Correction lens group (second optical member)
13, 14 Moving frame 15 Light shielding member 15a Movable member 15b Support member 15c Rotating shaft 15d Pressing rings 15e, 15f Coil spring (biasing means)

Claims (5)

A lens device having a plurality of moving groups that move in an optical axis direction,
A first moving frame that holds the first optical member, and a second moving frame that holds the second optical member,
In a lens device in which a cutout for allowing a part of the second moving frame to escape is formed in the first moving frame,
The first moving frame is provided with a light blocking member that blocks the notch at a predetermined position in the optical axis direction,
The light-blocking member has a variation unit that can change at least one of a relative position and a posture with respect to the first moving frame by a linear force caused by movement of the second moving frame in an optical axis direction. Lens device.   2. The lens according to claim 1, wherein the variation unit includes an urging unit that urges the light blocking member toward the first moving frame, and a rotation shaft that rotates the light blocking member. 3. apparatus. The light shielding member is a ferromagnetic material,
The first moving frame and the second moving frame have magnets,
When the first moving frame and the second moving frame are separated from each other, the light shielding member is fixed to the magnet of the first moving frame to be integrated with the first moving frame. Moved
When the first moving frame and the second moving frame are close to each other, the light shielding member is fixed to the magnet of the second moving frame, so that the light shielding member is integrally formed with the second moving frame. The lens device according to claim 1, wherein the lens device is moved. The light shielding member has a ferromagnetic material or a magnet,
The first moving frame and the second moving frame have a magnet or a ferromagnetic material,
When the first moving frame and the second moving frame are separated from each other, the ferromagnetic material or magnet of the light shielding member and the magnet or ferromagnetic material of the first moving frame are fixed. The light shielding member is moved integrally with the first moving frame,
When the first moving frame and the second moving frame are close to each other, the ferromagnetic material or magnet of the light shielding member and the magnet or ferromagnetic material of the second moving frame are fixed. The lens device according to claim 1, wherein the light shielding member is moved integrally with the second moving frame.   An imaging apparatus comprising: the lens device according to claim 1; and an imaging device that receives subject light from the lens device.

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