JP2009031532A - Lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel incorporating a shutter device and capable of fixing the shutter device by a simple configuration. <P>SOLUTION: The lens barrel includes a shutter unit, and a fixing body for fixing the shutter unit. The shutter unit has a flat shape with an annular section, part of which is notched. An engagement part is disposed on the bottom face of the annular section. An engagement part is engaged with a corresponding engagement part disposed in the fixing body. Thus, the shutter unit and the fixing body are fixed near the notched part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lens barrel incorporating a shutter device.

  Conventionally, in order to reduce the size of the lens barrel, a configuration has been proposed in which the actuator portion of the shutter device is disposed in the gap between each group. For example, as described in Patent Document 1, a configuration has been proposed in which the lens barrel can be reduced in size with respect to the optical axis direction by disposing the actuator portion of the shutter device in the gap of the second group lens.

  However, in the case of such a configuration, when a focus lens is mounted, a focus drive mechanism (for example, a stepping motor) protrudes in the outer peripheral direction, which increases the size of the lens barrel. Further, since the frame of the second group lens becomes complicated, there is a high possibility that the high-precision zoom function will be impaired.

In addition, as a method of supporting the internal parts of the lens barrel, screw fastening and a fastening method using the elastic force of the engaging claw have been proposed and implemented, but there is an increase in the number of parts and the risk of engaging by deforming high-precision parts. There was sex.
JP 2005-250436 A

  An object of the present invention is to provide a lens barrel that has a built-in shutter device and can be fixed with a simple configuration. At this time, the lens attached to the shutter device can be prevented from inadvertently increasing the outer peripheral size of the lens barrel, and the lens can be formed with a small number of parts without applying extra external force to the fixed portion of the shutter device. It is desirable that the lens barrel can be reduced in size.

  In order to solve the above problems, the lens barrel of the present invention is a lens barrel that includes a shutter unit and a fixed body that fixes the shutter unit, and the shutter unit is partially cut away. It has a planar shape with an annular part, an engaging part is provided on the bottom surface of the annular part, and the engaging part is engaged with an engaged part provided in the fixed body, in the vicinity of the notched part. The shutter unit and the fixed body are fixed.

  According to the present invention, it is possible to provide a lens barrel that has a built-in shutter device and can be fixed with a simple configuration.

(Embodiment)
FIG. 1 is an exploded perspective view of a lens barrel 100 according to an embodiment of the present invention. The lens barrel 100 includes a first group lens unit 110, a second group lens unit 120, a shutter device 130, a third group lens unit 140, a fourth group lens unit 150, a fixed frame 160, a cam barrel 170, a fixing member 180, and a focus driving mechanism 190. Is provided.

  The first group lens unit 110 and the second group lens unit 120 function as a zoom lens. The shutter device 130 is supported and fixed to the third group lens unit 140. Here, the shutter device 130 also includes an aperture function unit. The third group lens unit 140 functions as an image blur correction lens. The fourth group lens unit 150 functions as a focus lens.

  The fixed cylinder 160 includes a straight groove, and acts as a guide for moving the second group lens unit 120 and the third group lens unit 140 forward and backward in the optical axis direction. The fixed cylinder 160 cannot rotate about the optical axis.

  The cam cylinder 170 is rotated by a motor unit (not shown). The cam cylinder 170 has a cam groove on its side surface, and the first group lens unit 110, the second group lens unit 120, and the third group lens unit 140 each have a cam pin inserted into the cam groove, and the optical axis along the groove shape. Move in the direction. The fixing member 180 is fixed and held on the camera body.

  The focus drive mechanism 190 is a stepping motor provided with a lead screw (not shown), and the fourth group lens unit 150 provided with a rack (not shown) is engaged with the lead screw, and moves in the optical axis direction by the rotation of the motor.

  FIG. 2 is a sectional view of the lens barrel 100 according to the embodiment of the present invention. The focus drive mechanism 190 is disposed within the outer periphery of the fixed frame 160. In this case, if the shutter device 130 and the third group lens unit 140 are simply formed in an annular shape, they interfere with the focus drive mechanism 190 in the optical axis direction. Therefore, in the present invention, the focus driving mechanism 190 is placed within the outer periphery of the fixed frame 160 by adopting a structure in which the shutter device 130 and the third group lens unit 140 escape from the portion that interferes with the focus driving mechanism 190 in the optical axis direction. It can be placed and is downsized. That is, a part of the annular shape of the shutter device 130 is cut out.

  FIG. 3 is a perspective view of the shutter device 130 and the third group lens unit 140. The shutter device 130 is fixed to the third group lens unit 140. The shutter device 130 and the third group lens unit 140 are provided with an escape portion 131 in order to avoid interference with the focus drive mechanism 190. With this structure, the movement of the shutter device 130 and the third group lens unit 140 in the optical axis direction is not hindered.

  FIG. 4 is an exploded perspective view of the shutter device 130. The shutter device 130 includes a base part 133 and a cover part 134. The base 133 is provided with an actuator (not shown) for driving the shutter blades. The cover part 134 is fastened and held on the base part 133 to hold shutter blades and the like. The cover part 134 is integrally provided with an engaging part 135 for engaging the shutter device 130 with the third group lens unit 140. The engaging portion 135 is provided on the bottom surface of the shutter device 130. Thereby, since it is not necessary to prepare a space for disposing the engaging portion 135, the outer diameter of the shutter device 130 can be reduced.

  FIG. 5 is an assembly explanatory diagram when the shutter device 130 is engaged with the third group lens unit 140. The third group lens unit 140 is provided with an engagement hole as an engaged portion for engaging the engaging portion 135. The shutter device 130 slides the engaging portion 135 provided in the cover portion 134 as shown by the arrow in FIG.

  FIG. 6 is an assembly explanatory diagram when the shutter device 130 is fastened to the third group lens unit 140. After engaging the engaging portion 135 provided in the cover portion 134, the cylindrical protrusion 137 provided in the cover portion 134 is further inserted into the insertion hole 142 provided in the third group lens unit 140. The positional relationship between the shutter device 130 and the third group lens unit 140 is determined by the engagement between the engagement portion 135 and the engagement hole and the insertion of the cylindrical protrusion 137 into the insertion hole 142. The self-tapping screw 136 is fastened to a pilot hole provided in the third group lens unit 140 on the opposite side across the engaging portion 135 and the optical axis center.

  FIG. 7 is a cross-sectional view of the engaging portion 135. The engaging portion 135 is engaged with the third group lens unit 140 as illustrated. The engaging portion 135 can be inserted into the third group lens unit without elastic deformation. Therefore, assembly is possible without applying an external force to the shutter device 130. As shown in FIG. 6, the shutter device 130 is fixed in the optical axis direction by providing a fastening portion on the opposite side across the optical axis center. By adopting this structure, it is possible to make one fastening point, and the number of parts such as the self-tapping screw 136 can be reduced. Further, the engaging portion 135 is provided at a position overlapping the shutter unit 130 in the optical axis direction, and does not jump out in the outer peripheral direction. As a result, the shutter unit 130 can be reduced in size.

  FIG. 8 is a cross-sectional view of the cover portion 134 at the engaging portion 135 portion. In forming the shape, the engaging portion 135 does not use a slide structure for the mold, and has a shape that can be die-cut using the illustrated surface as a parting line.

  The shutter device 130 is an example of a shutter unit according to the present invention. The third group lens unit 140 is an example of a fixed body of the present invention.

  In this embodiment, the shutter device 130 is fixed to the third group lens unit 140, but the present invention is not limited to this. For example, it may be fixed to the fourth group lens unit 150.

  In the present embodiment, the focus lens driving mechanism 190 is arranged in the notched portion of the shutter device 130, but the present invention is not limited to this. For example, a zoom lens driving mechanism may be arranged, or another member may be arranged.

  The present invention can be applied to a lens barrel having a built-in shutter device. Specifically, the present invention can be applied to a digital camera, a movie, or a lens barrel used for these.

1 is an exploded perspective view of a lens barrel according to an embodiment of the present invention. Sectional drawing of the lens-barrel concerning embodiment of this invention Perspective view of shutter device and third group lens unit Disassembled perspective view of shutter device Assembly explanatory diagram when engaging the shutter device with the third group lens unit Assembly explanatory diagram when fastening the shutter device to the third group lens unit Sectional view of shutter device and third group lens unit Sectional view at the engaging part of the cover part

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Lens barrel 110 1st group lens unit 120 2nd group lens unit 130 Shutter device 131 Escape part 133 Base part 134 Cover part 135 Engagement part 136 Self tap screw 137 Cylindrical protrusion 140 3rd group lens unit 142 Insertion hole 150 4th group lens unit 160 Fixed cylinder 170 Cam cylinder 180 Fixed member 190 Focus drive mechanism

Claims (4)

A lens barrel including a shutter unit and a fixed body for fixing the shutter unit;
The shutter unit has a planar shape having an annular part with a part cut away;
An engagement portion is provided on the bottom surface of the annular portion, and the engagement portion is engaged with an engaged portion provided in the fixed body,
Fixing the shutter unit and the fixed body in the vicinity of the notched portion;
Lens barrel. The lens barrel according to claim 1, wherein the engaging portion is a hook-shaped protrusion, and is engaged by being slid and inserted into the engaged portion. The lens barrel according to claim 1, wherein the fixed body fixes a correction lens for optically correcting blur of a subject image. The lens barrel according to claim 3, wherein a focus driving mechanism for driving the focus lens is disposed in the notched portion.

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