JP5577642B2 - Lens barrel - Google Patents

Description

  The present invention relates to a lens barrel of an image pickup apparatus, and more particularly to a driving mechanism for a lens frame and a barrier of a photographing lens.

  In recent years, digital still cameras and video movies using an image sensor such as a charge coupled device (CCD) and a complementary metal-oxide semiconductor (CMOS) sensor have been widely used. Generally, a lens barrel for forming an optical image of a subject on an image sensor is attached to these digital still cameras and video movies. In particular, in digital still cameras, a retractable type in which a lens barrel is housed in a camera body when shooting is not widely used. A retractable lens barrel is described in Patent Document 1, for example.

  As described in Patent Document 1, the retractable lens barrel includes a fixed barrel and a movable barrel. The movable lens barrel is extended or stored with respect to the fixed lens barrel arranged in the camera body.

  Further, in many of the lens barrels constituting these imaging apparatuses, a focus lens for focusing a subject image on the imaging element is disposed in the focus lens frame, and the focus lens frame is placed in the lens barrel. The lens group arranged is moved in the optical axis direction.

  In addition, a barrier unit including a barrier for protecting the objective lens is disposed on the front surface of the objective lens serving as a photographing lens.

  On the other hand, Patent Documents 2 and 3 disclose configurations for restricting the movement of the focus lens frame.

JP 2008-185786 JP JP 2006-301672 A International Publication No. 2004/010813

  With the recent miniaturization of imaging devices, further miniaturization of lens barrels is desired.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems and provide a lens barrel that realizes a reduction in diameter.

  In order to achieve the above object, a lens barrel of the present invention holds a master flange on which an image sensor is arranged, a guide shaft formed on the master flange, and a focus lens that focuses the subject image on the image sensor. And a focus lens frame that slides in the axial direction of the guide shaft, and a lens group including an objective lens and a barrier that protects the objective lens, and a barrier opening / closing angle that controls the opening / closing operation of the barrier is formed on the master flange. In addition, a restricting portion for restricting the rotational movement of the focus lens frame with respect to the guide shaft is provided integrally with the barrier opening / closing angle.

  According to such a configuration, since the restricting portion for restricting the rotational movement of the focus lens frame with respect to the guide shaft is provided integrally with the barrier opening / closing angle, the lens barrel can be reduced in size by effectively utilizing the space. it can.

  As described above, according to the present invention, since the restricting portion for restricting the rotational movement of the focus lens frame with respect to the guide shaft is provided integrally with the barrier opening / closing angle, the lens barrel can be downsized by effectively utilizing the space. can do.

It is sectional drawing at the time of Wide of the lens barrel in one embodiment of this invention. It is sectional drawing at the time of Tele of the lens barrel. It is sectional drawing at the time of collapsing of the lens barrel. It is a schematic diagram which shows the opening-and-closing method of the opening-and-closing wing of the barrier unit of a lens-barrel. It is a perspective view which shows the state which incorporated the 3rd lens group unit in the master flange of the lens-barrel in one embodiment of this invention. FIG. 6 is a perspective view showing a state in which a second lens frame is further incorporated in the state of FIG. 5. It is a figure explaining the detail of operation | movement with the barrier opening-and-closing angle and barrier drive pin of the lens-barrel in one embodiment of this invention.

  Hereinafter, a lens barrel according to an embodiment of the present invention will be described with reference to the drawings, taking as an example an imaging apparatus using a retractable lens barrel.

(Embodiment)
FIG. 1 shows the state of a lens barrel during Wide, which is normal shooting with a zoom magnification (telephoto magnification) of 1 in the embodiment, and FIG. 2 shows the maximum telephoto with the zoom magnification in the embodiment as the maximum magnification. FIG. 3 is a cross-sectional view showing a state of the lens barrel at a certain Tele, and a state in which the lens barrel at the time of non-photographing in the embodiment is retracted.

  First, the overall configuration and operation of the lens barrel will be described.

  1 to 3, the lens barrel 100 includes a fixed barrel 110 and a movable barrel 120 held inside the fixed barrel 110. The movable lens barrel 120 moves so as to be drawn forward relative to the fixed lens barrel 110 or housed in the fixed lens barrel 110.

  The movable lens barrel 120 includes a first movable lens barrel 120a, a second movable lens barrel 120b, and a third movable lens barrel 120c. The second movable lens barrel 120b is held inside the third movable lens barrel 120c, and the first movable lens barrel 120a is held inside the second movable lens barrel 120b.

  That is, the second movable lens barrel 120b is extended with respect to the third movable lens barrel 120c, and the first movable lens barrel 120a is extended with respect to the second movable lens barrel 120b. Further, the second movable lens barrel 120b is accommodated in the third movable lens barrel 120c, and the first movable lens barrel 120a is accommodated in the second movable lens barrel 120b.

  As described above, the first moving barrel 120a, the second moving barrel 120b, and the third moving barrel 120c are extended forward relative to the fixed barrel 110, or the first movement to the fixed barrel 110 is performed. The lens barrel 120a, the second moving lens barrel 120b, and the third moving lens barrel 120c are accommodated.

  Therefore, when the first moving lens barrel 120a to the third moving lens barrel 120c are extended forward, the first moving lens barrel 120a is extended to the forefront.

  The first moving lens barrel 120a holds a first lens group 140a, which is an objective lens serving as a photographing lens, via the first lens frame 130a, and the first lens group 140a is moved to the camera cam frame 160 and a rectilinear frame. 170, the zoom lens can be moved by moving in the optical axis direction.

  The second movable lens barrel 120b holds the second lens group 140b via the second lens frame 130b, and the fixed lens barrel 110 receives the third lens frame 130c, which is a focus lens frame. A third lens group 140c that is a focus lens is held.

  The first lens frame 130a is fixed to the first movable lens barrel 120a, the second lens frame 130b is held by the second movable lens barrel 120b so as to be movable on the optical axis, and the third lens frame 130c is The fixed barrel 110 is held movably on the optical axis.

  The first lens group 140a to the third lens group 140c are each configured by combining a plurality of lenses, and the first lens group 140a is a lens group serving as an objective lens for capturing an optical image of a subject. The second lens group 140b is a zoom lens group, and the third lens group 140c is a focus lens group. When photographing, the zoom and focus of the optical image are adjusted by changing the interval between the first lens group 140a to the third lens group 140c.

  Next, the lens barrel 100 will be described in more detail. 1 to 3, the first movable lens barrel 120a includes a barrier unit 150 on the front surface for protecting the first lens group 140a. The barrier unit 150 is provided with an open / close wing 150a. The open / close wing 150a opens at the time of photographing, and the first movable lens barrel 120a, the second movable lens barrel 120b, and the third movable lens barrel 110 are fixed to the fixed lens barrel 110 when not photographing. In the retracted state in which the movable lens barrel 120c is housed, the open / close wing 150a is closed to protect the first lens group 140a.

  The second movable lens barrel 120 b includes a cylindrical camera cam frame 160 and a cylindrical rectilinear frame 170 held inside the camera cam frame 160. The first moving lens barrel 120a is movably held on the optical axis inside the rectilinear frame 170, and the second lens frame 130b is movably held on the optical axis by the rectilinear frame 170. . A cam groove is formed on the inner surface of the camera cam frame 160, and the first lens group 140a and the second lens group 140b are moved in the optical axis direction by the cam groove. A rectilinear groove is formed in the rectilinear frame 170, and the first lens group 140a and the second lens group 140b are linearly moved by the rectilinear frame 170.

  The second lens frame 130b includes a shutter unit 180, a camera shake correction mechanism 185, and an aperture mechanism. The shutter 180a of the second lens group 140b for zooming is opened and closed by the shutter unit 180, the camera shake correction is performed by the camera shake correction mechanism 185, and the diaphragm is adjusted by the diaphragm mechanism. Electric signals for controlling the shutter unit 180, the camera shake correction mechanism 185, the aperture mechanism, and the like are transmitted through a flexible wiring 190 for signal transmission.

  The third movable lens barrel 120 c includes a cylindrical drive frame 210 and a penetrating cam frame 220 held inside the drive frame 210. Inside the penetrating cam frame 220, the second movable lens barrel 120b is held movably on the optical axis.

  The fixed barrel 110 includes a cylindrical fixed frame 230 and a cylindrical master flange 240 fixed to the fixed frame 230. The third movable lens barrel 120c is held inside the fixed frame 230 so as to be movable on the optical axis, and the third lens frame 130c is held on the fixed frame 230 so as to be movable on the optical axis. . The third lens group 140c is a focusing lens group, and is fixed to a third lens frame 130c that is a focus lens frame. The third lens frame 130c is moved in the optical axis direction along a guide shaft 186 fixedly arranged on the master flange 240 by a driving mechanism such as a stepping motor fixedly arranged on the master flange 240.

  In addition, a CCD unit 260 as an imaging element is disposed on the optical axis on the master flange 240 at the center of the fixed barrel 110 via an IR cut glass 250 for blocking infrared rays.

  1 and 2 are views showing the state of the lens barrel 100 during photographing, and FIG. 3 is a view showing the state of the lens barrel 100 during non-photographing. As shown in FIG. 3, in the lens barrel 100 at the time of non-photographing, the open / close wings 150a of the barrier unit 150 provided in the first moving barrel 120a are closed, and the first lens group 140a is moved. Protect.

  Next, the principle of opening / closing operation of the opening / closing blade 150a of the barrier unit 150 of the lens barrel 100 will be described with reference to FIG. 4A and 4B are schematic views showing the opening / closing method of the opening / closing blade 150a of the barrier unit 150. FIG. 4A shows a state before the opening / closing blade 150a is closed, and FIG. 4B shows a state where the opening / closing blade 150a is closed. FIG.

  An opening 150b that opens to the first lens group 140a is provided at the tip of the barrier unit 150, and an opening / closing blade 150a that serves as a so-called barrier is disposed around the opening 150b. The open / close wing 150a is constituted by, for example, a pair of plate wings. The opening / closing wings 150a are configured to engage the barrier driving pins 401 and move the barrier driving pins 401 so that the opening 150b is closed by the opening / closing wings 150a. Further, the barrier drive pin 401 is moved by the barrier opening / closing angle 402.

  That is, by moving the barrier drive pin 401 while bringing the barrier open / close angle 402 arranged and fixed to the master flange 240 shown in FIGS. 150a is closed.

  FIG. 4A shows the state at the time of photographing shown in FIG. 1 or FIG. 2, in which the barrier driving pin 401 and the barrier opening / closing angle 402 of the barrier unit 150 are separated from each other. In this state, since the barrier driving pin 401 is not moved by the barrier opening / closing angle 402, the opening / closing blade 150a is housed around the barrier unit 150, and the opening 150b is located with respect to the first lens group 140a. Open.

  On the other hand, FIG. 4B shows a retracted state in the non-photographing state shown in FIG. 3, and the barrier drive pin 401 is brought into contact with the end of the barrier opening / closing angle 402 by the retracting of the first movable lens barrel 120a. The state is shown in which the open / close wing 150a is closed while being moved in contact. That is, the barrier unit 150 moves in the direction of the arrow A by the retracting of the first moving barrel 120a. When the barrier unit 150 moves a predetermined distance in the direction of arrow A, the end portion 402a of the barrier opening / closing angle 402 arranged and fixed to the master flange 240 and the barrier driving pin 401 come into contact with each other. Furthermore, when the barrier unit 150 moves to the master flange 240 side, the barrier opening / closing angle 402 relatively moves along the taper portion 401a provided on the barrier drive pin 401, so that the barrier drive pin 401 is moved in the direction indicated by the arrow B. Move in the direction by a predetermined distance H. As a result, the opening 150b of the barrier unit 150 is closed with the opening / closing blade 150a.

  Next, the configuration of the barrier opening / closing angle 402 of the lens barrel 100 in the embodiment will be described with reference to FIG. FIG. 5 is a perspective view showing a state in which the third lens group unit 500 is incorporated in the master flange 240 in the lens barrel 100 in the embodiment.

  The third lens group unit 500 includes a third lens group 140c that is a focus lens, a third lens frame 130c that is a focus lens frame, a guide member 501, and the like. The third lens frame 130 c uses a drive mechanism such as a stepping motor 502 fixedly arranged on the master flange 240, and the guide member 501 is fitted and slid on the guide shaft 186 fixedly arranged on the master flange 240. It moves in the direction of the optical axis.

  As shown in FIG. 5, a barrier opening / closing angle 402 is arranged and fixed on the master flange 240 by a method such as integral molding. The barrier opening / closing angle 402 is a member that rises vertically from the master flange 240 as a whole. The barrier opening / closing angle 402 is integrally provided with a restricting portion 503 that restricts the rotational movement of the third lens frame 130c that moves on the guide shaft 186 in the optical axis direction. Further, as shown by a broken line, a stepped portion 504 that comes into contact with the barrier drive pin 401 shown in FIG. 4 is provided on the surface of the barrier opening / closing angle 402 that faces the surface on which the restricting portion 503 is provided. The taper portion 505 has a thickness toward the surface, and the straight portion 506. Further, the barrier opening / closing angle 402 is provided with a light shielding wall 507 for shielding external light in the optical axis direction.

  That is, in the present embodiment, the barrier opening / closing angle 402 is integrally provided with a restricting portion 503 that restricts the rotational movement of the third lens frame 130c that moves in the optical axis direction on the guide shaft 186, and the third lens frame 130c is integrated. The third lens frame 130c can be moved in the optical axis direction while engaging the rotation stopper 508 and the restricting portion 503. As a result, the rotation of the third lens frame 130c is restricted, and the movement only in the optical axis direction can be performed reliably.

  FIG. 6 is a perspective view showing a state where the third lens group unit 500 is incorporated in the master flange 240 shown in FIG. 5 and a second lens frame 130b is incorporated. The second lens frame 130b includes a shutter unit 180, a camera shake correction mechanism 185, and an aperture mechanism. That is, as shown in FIG. 6, the barrier opening / closing angle 402 passes through the through portion 601 provided on the outer peripheral portion of the second lens frame 130 b, and the barrier unit 150 passes through the shutter unit that constitutes the second lens frame 130 b. It is made to contact | abut with the barrier drive pin 401 provided in this.

  Therefore, according to the lens barrel 100 in the embodiment, the rotation stop 508 of the third lens frame 130 c is integrally provided at the barrier opening / closing angle 402. Since it is not necessary to provide a separate rotation stop for the third lens frame 130c as a separate body, space can be used effectively, leading to downsizing of the lens barrel. In particular, by disposing the barrier opening / closing angle 402 and the rotation stopper 508 only in the penetrating portion 601, it is possible to make a configuration in which penetrating portions are not provided at a plurality of locations on the shutter unit. Thereby, since the area | region on the shutter unit for providing a penetration part can be reduced, the diameter reduction of a shutter unit and the diameter reduction of a lens-barrel are realizable.

  FIG. 7 is a diagram for explaining the operation of the barrier opening / closing angle 402 and the barrier driving pin 401 in more detail in the lens barrel 100 according to the embodiment, which is the same as that explaining the principle of the opening / closing operation in FIG. FIG. 6 is a cross-sectional view taken along line AA of the barrier opening / closing angle 402 in FIG. 5. FIG. 7A shows a state in which the barrier opening / closing wings are open during photographing, and FIG. 7B shows a state in which the barrier opening / closing wings are closed during non-photographing.

  As shown in FIG. 7A, the barrier opening / closing angle 402 is composed of a member that rises in the vertical direction from the master flange 240 as shown in FIG. 5, and the third lens frame 130c is formed on the vertical portion on one side. A restricting portion 503 that engages with the rotation stopper 508 is provided at a predetermined height. A stepped portion 504 is provided on the surface of the barrier opening / closing angle 402 that faces the surface on which the restricting portion 503 is provided. The stepped portion 504 is constituted by a tapered portion 505 that becomes thicker toward the master flange 240 and a linear portion 506. Further, the end portion of the barrier opening / closing angle 402 is configured to have an R portion 704. Further, the barrier drive pin 401 that comes into contact with the barrier opening / closing angle 402 has a tapered portion 401a formed at the tip thereof.

  As shown in FIG. 7B, when the retractable open / close wing is closed, the barrier drive pin 401 moves so that the taper portion 505 of the barrier drive pin 401 follows the taper portion 505 of the barrier open / close angle 402. .

  Accordingly, as described with reference to FIG. 4, when moving from the camera photographing standby state as shown in FIG. 1 to the retracted state of FIG. 3, the barrier drive pin 401 is moved in the direction of arrow I in FIG. Moving. As a result, the taper portion 401a of the barrier drive pin 401 and the R portion 701 of the barrier opening / closing angle 402 come into contact with each other, and the barrier drive pin 401 is pushed in the direction of arrow J. When the barrier drive pin 401 moves in the J direction, the open / close wing 150a of the barrier unit 150 is closed.

  As described above, in the embodiment, the restricting portion 503 that engages with the rotation stopper 508 of the third lens frame 130c is provided on one surface of the barrier opening / closing angle 402, and the barrier driving pin 401 moves to the opposite surface side. Like to do. That is, the movement of the barrier driving pin 401 and the movement of the rotation stopper 508 are configured so as not to interfere with each other. Therefore, the lens barrel 100 can be reduced in size by reducing the length in the optical axis direction.

  Further, as shown in FIG. 7, the barrier opening / closing angle 402 is provided with a step portion 504, and the step portion 504 is configured by a taper portion 505 that becomes thicker toward the master flange 240 and a linear portion 506. Yes. Therefore, the mechanical strength of the barrier opening / closing angle 402 integrated with the regulating portion 503 can be improved.

  Further, in this way, the barrier opening / closing angle 402 is integrally provided with the restriction portion 503 that engages with the rotation stopper 508. Therefore, when the rotation stopper is provided separately, the mechanical strength thereof is weak, and there are cases where the rotation stopper is broken when the lens barrel is assembled. Trouble can be eliminated.

  As shown in FIG. 6, the barrier opening / closing angle 402 is configured to pass through a penetrating portion 601 provided on the outer peripheral portion of the second lens frame 130 b, and further, the penetrating portion 601 is formed on the second lens frame 130 b. It arrange | positions through the provided partition wall 602. FIG. It is desirable to apply grease or the like as a lubricant to smooth the relative movement of the restricting portion 503 engaged with the rotation stopper 508 of the third lens frame 130c. However, when these greases infiltrate into the shutter unit disposed in the second lens frame 130b, a malfunction occurs in the operation of the shutter blades in the shutter unit. In the present embodiment, as shown in FIG. 6, the rotation stopper 508 and the restricting portion 503 to which grease is applied can be isolated from the inside of the shutter unit via the partition wall 602. Therefore, it is possible to improve the reliability of the lens barrel 100 by preventing grease from infiltrating into the shutter unit.

  The barrier opening / closing angle 402 is provided with a light shielding wall 507 for shielding external light in the optical axis direction. Therefore, the light shielding wall 507 can prevent external light from entering the second lens group 140b and the third lens group 140c, thereby realizing high-accuracy imaging. In addition, by providing the light shielding wall 507 at the barrier opening / closing angle 402, the mechanical strength of the barrier opening / closing angle 402 can be further improved, and reliability during assembly can be improved.

  As described above, according to the lens barrel of the embodiment, since the restricting portion for restricting the rotational movement of the third lens frame serving as the focus lens frame with respect to the guide shaft is provided integrally with the barrier opening / closing angle, Is not required to be formed on the master flange, and the lens barrel can be reduced in size by effectively utilizing the space.

  According to the present invention, the lens barrel can be miniaturized in the optical axis direction, and is useful when applied to an imaging apparatus such as a film camera, a digital camera, or a video camera. In particular, the present invention is useful when applied to a compact type digital camera that is required to be downsized.

DESCRIPTION OF SYMBOLS 100 Lens barrel 110 Fixed barrel 120 Moving barrel 120a First moving barrel 120b Second moving barrel 120c Third moving barrel 130a First lens frame 130b Second lens frame 130c Third lens Frame 140a First lens group 140b Second lens group 140c Third lens group 150 Barrier unit 150a Opening and closing blades 150b Opening 160 Camera cam frame 170 Linear frame 180 Shutter unit 180a Shutter 185 Camera shake correction mechanism 186 Guide shaft 190 Flexible wiring 210 Drive frame 220 Through cam frame 230 Fixed frame 240 Master flange 250 IR cut glass 260 CCD unit 401 Barrier drive pins 401a, 505 Tapered portion 402 Barrier opening / closing angle 402a End portion 500 Third lens unit 501 guide member 502 stepper motor 503 restricting portion 504 stepped portion 506 straight portion 507 shielding wall 508 rotation stopper 601 through portion 602 partition wall 701 R portion

Claims (4)

A master flange on which an image sensor is arranged;
A guide shaft formed on the master flange;
A focus lens frame that holds a focus lens for focusing an object image on the image sensor and slides in an axial direction of the guide shaft;
A lens group including an objective lens and a barrier protecting the objective lens;
An intermediate frame disposed between the focus lens frame and the lens group,
The master flange has a barrier opening / closing angle for controlling the opening / closing operation of the barrier,
The barrier has a barrier driving pin,
The intermediate frame has a penetrating portion on the outer peripheral portion,
The barrier driving pin abuts on the barrier opening / closing angle through the penetrating portion,
The master flange further has a restricting portion provided integrally with the barrier opening / closing angle,
The restricting portion restricts rotational movement of the focus lens frame with respect to the guide shaft ;
The master flange further includes a wall portion adjacent to the restricting portion, and a part of the wall portion is provided between the restricting portion and the focus lens frame, and blocks light from the optical axis direction. Prevent light from entering the focus lens,
A lens barrel characterized by that. The barrier drive pin is moved while being brought into contact with an end portion of the barrier opening / closing angle, and the barrier driving pin is moved in a direction of a surface facing the regulating portion of the barrier opening / closing angle. The lens barrel according to 1. The lens barrel according to claim 2, wherein a taper portion that is thicker toward the master flange surface is provided on a surface that faces the surface on which the restriction portion of the barrier opening / closing angle is provided. The lens barrel according to any one of claims 1 to 3, wherein the intermediate frame includes a shutter unit, and a partition wall is provided between the restricting portion and the shutter unit.

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