JP4796952B2 - Lens barrel - Google Patents

Description

  The present invention relates to a lens barrel that drives a lens mounted on a digital camera, a silver salt film camera, or the like in the direction of the optical axis, and more particularly to a lens barrel that includes a barrier mechanism in front of a lens closest to the subject.

  As a conventional lens barrel, a base to which a CCD or the like is attached, a fixed cylinder fixed to the base, a cam cylinder arranged to be rotatable and rectilinear inside the fixed cylinder, and movable in the optical axis direction inside the cam cylinder A first lens group and a second lens group supported by the second lens group, a third lens group supported movably with respect to the base behind the second lens group, a drive mechanism for rotationally driving the cam cylinder, and a first lens group There is known a device provided with a barrier mechanism or the like that is provided in the front and closes the opening when the lens is retracted to cover the lens (for example, see Patent Document).

Here, the first lens group includes a lens frame (inner holding frame) for fixing the lens, a barrier mechanism provided on the lens frame in front of the lens in the optical axis direction, and the like. In addition, the barrier mechanism is a barrier blade that opens and closes the opening of the lens frame (inner holding frame), a spring that biases the barrier blade to the open state, and drives the barrier blade in the closing direction against the biasing force of the spring when retracted The drive member etc. to be provided are provided.
In this lens barrel, the lens of the first lens group is fixed to the lens frame (inner holding frame), and the barrier blade always opens and closes in front of the lens (that is, the lens is always behind the barrier blade). Therefore, the lens and the barrier blade do not collide, and the barrier blade can be surely opened and closed.

  By the way, the first lens group that moves in the optical axis direction is designed to simplify the structure and reduce the thickness in the optical axis direction when retracted while ensuring a desired zoom ratio with a small number of lens group configurations. When the lens is relatively movable in the optical axis direction with respect to the lens frame, the lens may protrude forward in the optical axis direction from the opening / closing position of the barrier blade during shooting. If the opening / closing operation and the moving operation of the lens are not performed at a predetermined timing, there is a possibility that the lens impinges or interferes with the barrier blade in the closed state, and the intended function cannot be reliably ensured.

JP 2003-295256 A

  The present invention has been made in view of the above-mentioned problems of the prior art, and its object is to simplify the structure, reduce the number of parts, reduce the size, reduce the thickness, etc. An object of the present invention is to provide a lens barrel capable of reliably preventing a collision or interference between a barrier mechanism (barrier blades) and a lens and ensuring a desired function.

The lens barrel of the present invention is supported in such a manner as to be movable in the optical axis direction with respect to the first lens frame and the first lens frame, and is disposed in front of the lens in the optical axis direction with respect to the first lens cylinder holding the lens. A first lens group including a barrier blade supported to be openable and closable with respect to the first lens frame so as to open and close the opening, and a second lens group arranged behind the first lens group in the optical axis direction. A first drive mechanism for moving the first lens group and the second lens group in the optical axis direction and opening and closing the barrier blades along with the movement, and a range protruding forward in the optical axis direction from the barrier blades during photographing Including a second driving mechanism provided on the first lens frame to move the first lens cylinder in the optical axis direction, and a control means for driving and controlling the first driving mechanism and the second driving mechanism. A lens barrel, wherein the control means comprises: Convolutionally behind the optical axis direction than the barrier blades the first lens barrel in after bring the barrier blades fully open in the process to bring the initial position at the time of photographing the first lens group and the second lens group from the retracted position In order to extend the first lens group and the second lens group from the extended position to the retracted position from the extended position to the retracted position in order to extend from the rest position, the barrier blades are fully closed after the first lens cylinder is retracted to the rest position. Therefore, the second drive mechanism is drive-controlled based on the detection result of the drive amount of the first drive mechanism.
According to this configuration, the first lens group and the second lens group are moved in the optical axis direction by the first drive mechanism, and the first lens cylinder (lens) is moved to the first lens group by the second drive mechanism. It is moved relative to one lens frame in the optical axis direction, and zoom driving and focus driving are performed as a whole.
Here, the barrier blade is held by the first lens frame, and before the first lens frame (first lens group) reaches the initial position, that is, the first lens cylinder (lens) is moved by the second drive mechanism. Since the lens (first lens barrel) and the barrier blades can be prevented from colliding or interfering with each other because they are moved to the fully open state before being drawn forward in the optical axis direction with respect to the first lens frame. In operation, the barrier blade is moved to the fully closed state after the first lens tube is retracted and reaches the rest position, so that collision or interference between the lens (first lens tube) and the barrier blade can be prevented. It is possible to ensure the expected function. In other words, the structure is simplified, the number of parts is reduced, and the thickness is reduced in the direction of the optical axis, and the barrier blade is also surely prevented from colliding with or interfering with other parts (the lens or the first lens cylinder). It can be driven.
That is, the first drive mechanism is driven and controlled by the control means so that the first lens group and the second lens group are moved from the retracted position to the initial position and the barrier blades are fully opened. Based on the detection result of the driving amount, the second driving mechanism is driven and controlled to move the lens (first lens cylinder) so that it protrudes (feeds out) from the barrier blade, and the first driving mechanism is driven and controlled. Thus, when the first lens group and the second lens group are moved from the extended position to the retracted position through the initial position, the detection result of the driving amount of the first driving mechanism is obtained before the barrier blades are fully closed. Based on the driving control of the second drive mechanism and retracting the lens (first lens cylinder) to the rest position, collision or interference between the lens (first lens cylinder) and the barrier blade can be reliably prevented. .
In particular, when the first drive mechanism includes, for example, a DC motor or a stepping motor as a drive source, the drive amount is detected by a detection sensor or the like, and the opening / closing timing of the barrier blade and the first lens group are initially determined based on the detection result. The timing to reach the position is specified, and the second drive mechanism is driven and controlled based on these timings, so that the lens (first lens cylinder) can be reliably extended at a timing that does not interfere with the barrier blade.

In the above-described configuration, a configuration in which the initial position is positioned at a position extended forward by a predetermined amount from the retracted position in the optical axis direction can be employed.
According to this configuration, since the lens group (lens) is extended by a predetermined amount from the retracted position to the initial position, the barrier blade is easily and reliably moved from the fully closed position to the fully open position during the extension. be able to.

In the above structure, barrier blades, in conjunction with the movement of the first lens frame is formed in a so that is opened and closed, it is possible to adopt a configuration.
According to this configuration, since the barrier mechanism opens and closes the barrier blade in conjunction with the first lens frame , for example, when the first lens group moves from the retracted position to the initial position (draws), the movement ( The barrier blades are reliably moved from the fully closed state to the fully open state at a predetermined timing without using a dedicated drive source in conjunction with the operation in the middle of the feeding operation), that is, while simplifying the structure. It can be moved (fully opened).

  According to the lens barrel of the present invention having the above-described configuration, a barrier mechanism (barrier blade) is provided in a configuration including a barrier mechanism while achieving simplification of the structure, reduction in the number of parts, miniaturization, thinning, and the like. It is possible to obtain a lens barrel capable of reliably preventing a lens collision or interference and reliably guaranteeing an intended function.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings.
1 to 13 show an embodiment of a lens barrel according to the present invention. FIG. 1 is a front view of the lens barrel, and FIG. 2 is a cross-sectional view of the inside of the lens barrel as seen from the optical axis direction. FIGS. 3 to 7 are sectional views along the plane including the optical axis, FIGS. 8 and 9 are partial front views showing the fully closed and fully opened state of the barrier blade, and FIG. 10 is a part showing the barrier mechanism. FIG. 11 is a graph showing the retracted position, the opening / closing timing of the barrier spring, and the initial position. FIGS. 12 and 13 are sectional views of the apparatus showing the lens in the wide-angle end position and the telephoto end position.

As shown in FIGS. 1 to 7, the lens barrel rotates and rotates inside the base 10, the base 10 to which the imaging element PE such as the filter plate FP and CCD is mounted, the fixed cylinder 20 fixed to the base 10, and the fixed cylinder 20. A rotating cylinder 30 supported so as to be linearly movable in the optical axis direction L; a first cam cylinder 40 which is non-rotatable inside the rotating cylinder 30 and is fitted together with the rotating cylinder 30 so as to be linearly movable in the optical axis direction L; The first guide cylinder 50 is fitted inside the first cam cylinder 40 so as not to be rotatable and linearly movable in the optical axis direction L. The first guide cylinder 50 is non-rotatable inside the first guide cylinder 50 and goes straight in the optical axis direction L. The first lens group 60 fitted so as to be able to rotate, and the second cam cylinder 70 fitted so as to be rotatable in the optical axis direction L together with the first guide cylinder 50 while being rotatable inside the first lens group 60. Rotate inside the second cam cylinder 70 And the second guide cylinder 80, which is fitted together with the second cam cylinder 70 so as to be linearly movable in the optical axis direction L, is not rotatable inside the second guide cylinder 80 and can be linearly advanced in the optical axis direction L. The fitted second lens group 90 and the drive unit 100 that forms part of the first drive mechanism provided on the base 10 for rotationally driving the rotary cylinder 30 are provided on the first lens group 60 and are described later. A second driving mechanism 110 that drives the lens cylinder 62 in the optical axis direction L; a barrier mechanism 120 that is provided in the first lens group 60 and opens and closes its opening 64a; a detection sensor 130 that detects the retracted position of the rotating cylinder 30; A control unit (not shown) including a CPU or the like is provided as a control means for driving and controlling the first drive mechanism (drive unit 100) and the second drive mechanism 110.
Here, the first drive that performs zoom driving by relatively moving the first lens group 60 and the second lens group 90 in the optical axis direction L by the drive unit 100, the first cam cylinder 40, the second cam cylinder 70, and the like. The mechanism is configured.

  The base 10 is molded using a resin material, and as shown in FIGS. 1 to 7, an opening 11 through which light passes, and a recess formed behind the opening 11 to which the filter plate FP and the image sensor PE are attached. 12. Inclination that protrudes forward in the optical axis direction L to engage and disengage a part of the barrier unit 120 (a driving rod 122b of the driving lever 122 described later) and a holding unit 13 for holding the driving unit 100. The engaging projection 14 having the surface 14a, the recess 15 to which the detection sensor 130 is attached, and the like are formed. As shown in FIGS. 1 to 3, the holding portion 13 is formed so as to delimit a space for accommodating the gear train of the drive unit 100 in cooperation with a holding portion 21 of the fixed cylinder 20 described later.

The fixed cylinder 20 is molded using a resin material, and as shown in FIGS. 1 to 7, as shown in FIG. 1 to FIG. 7, a holding portion 21 that is bonded to the holding portion 13 of the base 10 and an axis parallel to the optical axis direction L It is formed so as to include a cylindrical portion 22 or the like formed in a cylindrical shape having a heart.
As shown in FIGS. 2 and 3, the cylindrical portion 22 includes a cutout portion 22a cut out so as to allow a part of a gear 108, which will be described later, to enter inside without contact, and a rotary cylinder 30 (follower pin, which will be described later). 31) Three cam grooves 22b formed on the inner peripheral surface to exert a cam action, a guide groove 22c for guiding the first cam cylinder 40 (a projection 41 described later) only in the optical axis direction L, and the like. Is formed.

  The rotary cylinder 30 is molded into a cylindrical shape having a shaft center parallel to the optical axis direction L using a resin material, and is inserted into the cam groove 22b of the fixed cylinder 20 as shown in FIGS. Three follower pins 31 arranged at equal intervals on the outer peripheral surface, a tooth row (arc-shaped rack portion) 32 formed on the rear end side of the outer peripheral surface to mesh with a gear 108 described later, and extending in the optical axis direction L and described later The guide groove 33 for receiving the tip of the follower pin 71 is provided. The rotating cylinder 30 is rotated by the gear 108 by a rotational driving force, and rotates in the optical axis direction L.

The first cam cylinder 40 is molded into a cylindrical shape having a central axis parallel to the optical axis direction L using a resin material, and as shown in FIG. 3, a protrusion 41 inserted into the guide groove 22c of the fixed cylinder 20, Three follower pins 71 of a second cam cylinder 70 described later are received and three penetrating cams 42 that exert a cam action in the optical axis direction L, and protrusions 52 of a first guide cylinder 50 described later are received and guided in the optical axis direction L. It is formed to include a guide groove 43 and the like.
The first cam cylinder 40 is nestably fitted inside the rotary cylinder 30 and is held by the fixed cylinder 20 so as not to rotate, and moves in the optical axis direction L together with the rotary cylinder 30. It has become.

  The first guide cylinder 50 is molded into a cylindrical shape having an axis parallel to the optical axis direction L using a resin material. As shown in FIGS. 1 and 3, a follower pin 71 of a second cam cylinder 70 described later is provided. Three arc-shaped long holes 51 formed so as to penetrate a predetermined length in the circumferential direction so as to freely receive a predetermined angular range in a plane perpendicular to the optical axis L, and a guide for the first cam cylinder 40 Three protrusions 52 formed to protrude radially outward to be inserted into the groove 43 and a protrusion 63b of the first lens group 60 described later are formed and formed on the inner peripheral surface to guide in the optical axis direction L. A guide groove 53 is formed. The first guide cylinder 50 is moved in the optical axis direction L relative to the first cam cylinder 40 while being held in a non-rotatable state in a state of being nested inside the first cam cylinder 40. It is supposed to be.

The first lens group 60 is molded using a resin material into a cylindrical shape having an axis parallel to the optical axis direction L, and as shown in FIGS. 1, 3 to 6, the first lens frame 61 and the lens G1. And a first lens cylinder 62 and the like that move relative to the first lens frame 61 in the optical axis direction L.
As shown in FIG. 3, the first lens frame 61 is formed of an outer cylindrical portion 63, an inner cylindrical portion 64, a front end wall portion 65, and the like.

As shown in FIG. 3, the outer cylindrical portion 63 is inserted into a notch portion 63 a through which a follower pin 71 of a second cam cylinder 70 to be described later passes in a radially outward direction without contact and a guide groove 53 of the first guide cylinder 50. A protrusion 63b that protrudes radially outward as much as possible, a protrusion 63b that protrudes radially inward to be inserted into an outer cam groove 72 of the second cam cylinder 70 described later, and is formed at equal intervals in the circumferential direction. It is formed so as to include three follower pins 63c and the like.
As shown in FIG. 3, the inner cylindrical portion 64 is formed so as to insert and support the first lens cylinder 62 so as to be movable (movable and retractable) in the optical axis direction L, and a pair of barrier blades described later. 121 and 121 define an opening 64a that is opened and closed.

  As shown in FIGS. 3 to 8 and 10, the front end wall portion 65 is a bearing hole that rotatably supports a fixing portion 65 a for fixing a driving motor 111 described later and one end portion of a lead screw 115 described later. 65b, a support shaft 65c that rotatably supports an intermediate gear 113 to be described later, two fitting holes 65d and 65d for fitting two guide shafts 117 and 117 to be described later, and one end of a coil spring 118 to be described later. A seat surface portion 65e, two support shafts 65f and 65f for swingably supporting a pair of barrier blades 121 and 121 described later, a support shaft 65g for swingably supporting a drive lever 122 described later, and one end of a spring 123 described later 65h, and a fixing portion 65i for fixing a detection sensor 119 described later. Further, as shown in FIGS. 6, 7, and 10, the front end wall portion 65 defines a blade chamber W that accommodates a pair of barrier blades 121 and 121 of a barrier mechanism 120 described later in an openable and closable manner.

The first lens cylinder 62 is molded using a resin material, and, as shown in FIGS. 3 to 7, is inserted into the inner cylindrical portion 64 and extends from the cylindrical portion 62a to hold the lens G1, and will be described later. Connecting portions 62b and 62b that are slidably connected to the guide shafts 117 and 117, a seat surface portion 62c that is formed on the connecting portion 62b and receives the other end of a coil spring 118 described later, and extends from the connecting portion 62b. It is formed so as to include a detection piece 62d formed and detected by a detection sensor 119, which will be described later, a nut holding portion 62e that extends from the cylindrical portion 62a and holds a nut 116 that will be described later unrotatably.
The first lens cylinder 62 is moved relative to the first lens frame 61 of the first lens group 60 in the optical axis direction L by the driving force of the second driving mechanism 110 described later. ing.

As shown in FIGS. 3 to 5, the second drive mechanism 110 is configured to rotate integrally with the drive motor 111 including a stepping motor, the drive gear 112, the intermediate gear 113, the driven gear 114, and the driven gear 114. A lead screw 115 formed extending in the optical axis direction L, a nut 116 held by the nut holding portion 62e of the first lens cylinder 62 in a state of being screwed to the lead screw 115, and a connecting portion 62b of the first lens cylinder 62 , 62b are slidably fitted to guide two guide shafts 117, 117 for guiding in the optical axis direction L, a coil spring 118 for biasing the first lens cylinder 62 rearward in the optical axis direction L, first A detection sensor 119, which is a transmission type optical sensor including a light emitting element and a light receiving element for detecting the detected piece 62d of the lens cylinder 62, is provided.
Then, by rotating the drive motor 111, the first lens barrel 62 (lens G1) is moved to the first lens frame 61 via the drive gear 112 → the intermediate gear 113 → the driven gear 114 → the lead screw 115 → the nut 116. With respect to the optical axis direction L, the region including the range protruding forward in the optical axis direction L from the pair of barrier blades 121 and 121 is reciprocated. Focusing is performed at the focal position (focus drive).

The second cam cylinder 70 is molded into a cylindrical shape having a central axis parallel to the optical axis direction L using a resin material, and as shown in FIG. 3, a cutout of the first lens group 60 (outer cylindrical portion 61). Three follower pins 71 inserted into the penetration cam 42 of the first cam barrel 40 and the guide groove 33 of the rotary barrel 30 and the follower pin 63c of the first lens group 60 through the portion 63a, the arc-shaped elongated hole 51 of the first guide barrel 50. Three outer cam grooves 72 that receive and exert a cam action in the optical axis direction L, and three inner cam grooves 73 that receive a follower pin 93 of the second lens group 90 described later and exert a cam action in the optical axis direction L are provided. Is formed.
The second cam cylinder 70 rotates in response to a cam action by the first cam cylinder 40 in a state in which the second cam cylinder 70 is nested inside the outer cylindrical portion 63, and the first guide cylinder 50 is moved in the optical axis direction L. While moving together, the first lens group 60 and the second lens group 90 are cammed in the optical axis direction L.

The second guide cylinder 80 is molded into a cylindrical shape having an axis parallel to the optical axis direction L using a resin material, and is non-rotatably connected to the first guide cylinder 50 as shown in FIG. The connecting piece 91 and three guide slits 82 for guiding the follower pin 93 of the second lens group 90 only in the optical axis direction L are provided.
The second guide cylinder 80 is nested inside the second cam cylinder 70, is held non-rotatable, moves in the optical axis direction L together with the first guide cylinder 50, and is moved to the second lens. The movement in the optical axis direction L is allowed while restricting the rotation of the group 90.

The second lens group 90 is molded using a resin material into a cylindrical shape having an axis parallel to the optical axis direction L. As shown in FIGS. 3 to 7, a cylindrical portion 91 and a cylindrical portion for holding the lens G2. An extension portion 92 extending in the radial direction from 91, and projecting radially outward from the extension portion 92 to be inserted into the inner cam groove 73 of the second cam cylinder 70, and formed at equal intervals in the circumferential direction. And three follower pins 93 and the like.
The second lens group 90 is moved in the optical axis direction L by receiving a cam action by the second cam cylinder 70 while being restricted by the second guide cylinder 80.

As shown in FIG. 2, the drive unit 100 (first drive mechanism) includes a drive motor 101 including a DC motor or a stepping motor fixed to the base 10, a drive gear 102 directly connected to the drive motor 101, and a drive gear 102. Gear 103a meshing with gear 103a, worm gear 103b integrally formed coaxially with gear 103a, impeller 103c rotating integrally with worm gear 103b, worm wheel 104a meshing with worm gear 103b, and coaxial with worm wheel 104a The gear 104b formed integrally, the gear 105 meshed with the gear 104b, the gear 106a meshed with the gear 105, the gear 106b formed coaxially with the gear 106a, the gear 107 meshed with the gear 106b, and the gear 107 At the same time as meshing, the teeth of the rotating cylinder 30 (arc Gear 108 that meshes with the rack portion) 32 is formed by the detecting sensor 109 for detecting the amount of rotation of the impeller 103c.
The detection sensor 109 includes a light emitting element and a light receiving element, and the rotation of the impeller 103c causes the blade to cross the optical path between the two elements so that a signal corresponding to the amount of light incident on the light receiving element is output. ing.

  That is, by rotating the drive motor 101, the drive gear 102 → the gear 103a → the worm gear 103b → the worm wheel 104a → the gear 104b → the gear 105 → the gear 106a → the gear 106b → the gear 107 → the gear 108 → the tooth row 32. The rotation cylinder 30 is rotated, and the rotation amount of the impeller 103c is detected by the detection sensor 109, whereby the amount of extension from the retracted position to the initial position, the amount of extension in the optical axis direction L from the initial position, and the amount of retraction are determined. By detecting, the entire driving amount is detected.

  6 to 10, the barrier mechanism 120 is accommodated in a blade chamber W defined by the front end wall portion 65 of the first lens group 60, and a pair of barrier blades 121, 121 for opening and closing the opening 64a. A drive lever 122 that opens and closes by driving the pair of barrier blades 121 and 121 in an interlocking manner, a torsion spring 123 that urges the drive lever 122 in a direction to fully open the pair of barrier blades 121 and 121, and a pair of barrier blades 121 and 121. Two torsion springs 124, 124, etc., which are each urged to rotate in the closing direction, are provided.

The pair of barrier blades 121 and 121 are swingably supported by a support shaft 65f, and cooperate with each other to fully open or fully close the opening 64a.
The drive lever 122 is swingably supported by the support shaft 65g, and is provided so as to protrude forward in the optical axis direction L at one end side thereof and to be engaged with a part of the pair of barrier blades 121 and 121. And a driving rod 122b, a latching protrusion 122c, and the like provided so as to protrude toward the rear in the optical axis direction L and to engage with the engaging protrusion 14 of the base 10. .

The torsion spring 123 is arranged around the support shaft 65g, and its one end 123a is hooked on the hooking protrusion 122c of the drive lever 122, and the other end 123b is hooked on the hooking protrusion 65h of the front end wall portion 65. The drive lever 122 is urged to rotate so as to rotate clockwise in FIGS. 8 and 9, that is, to fully open the pair of barrier blades 121 and 121.
The two torsion springs 124 are arranged around the support shaft 65f, and one end 124a thereof is hooked on the drive pin 122a, and the other end 124b is hooked on a part of the barrier blade 121. Rotating bias is applied in the direction of closing.

  That is, in the barrier mechanism 120, when the first lens group 60 (first lens frame 61) and the second lens group 90 are in the retracted position as shown in FIG. Due to the cam action, the drive lever 122 rotates by a predetermined angle against the rotational biasing force of the torsion spring 123, and as shown in FIG. 8, the pair of barrier blades 121 and 121 fully closes the opening 64a. Is in a state.

Then, by the first driving mechanism, the first lens group 60 (first lens frame 61) and the second lens group 90 are moved by a predetermined amount from the retracted position shown in FIG. 6 to the initial position at the time of photographing shown in FIG. When drawn forward in the optical axis direction L, the drive rod 122b is disengaged from the engaging protrusion 14 before reaching the initial position, and the drive lever 122 is rotated by a predetermined angle by the rotational biasing force of the torsion spring 123. As shown in FIGS. 7 and 9, the pair of barrier blades 121 and 121 move to a state in which the opening 64a is fully opened.
On the other hand, the first driving mechanism causes the first lens group 60 (first lens frame 61) and the second lens group 90 to move from the initial position shown in FIG. 7 toward the retracted position shown in FIG. When it is retracted to the rear of L, the drive rod 122b engages with the inclined surface 14a of the engagement projection 14 and receives a cam action, and the drive lever 122 resists the rotational biasing force of the torsion spring 123 by a predetermined angle. As shown in FIGS. 6 and 8, the pair of barrier blades 121 and 121 are moved to a state in which the opening 64a is fully closed.

  Thus, since the barrier mechanism 120 is formed to open and close the pair of barrier blades 121 and 121 in conjunction with the movement of the first lens frame 61, the first lens group 60 is moved from the retracted position to the initial position. The pair of barrier blades is linked to the timing during the movement (feeding operation) without using a dedicated drive source, that is, while simplifying the structure, etc. 121, 121 can be reliably moved (fully opened) from the fully closed state to the fully open state.

  The detection sensor 130 is a reflection type optical sensor including a light projecting element that emits detection light and a light receiving element that receives reflected light reflected by an object. Then, the detection sensor 130 detects a part of the rotating cylinder 30 moving in the optical axis direction L (whether or not the detection light is reflected from the attached reflection sheet), whereby the rotating cylinder 30, the first Whether the lens group 60 and the second lens group 90 are located at the retracted position is detected.

Here, the first lens group 60 moved in the optical axis direction L by the first drive mechanism (the drive unit 100 including the drive motor 101, the first cam cylinder 40, the second cam cylinder 70, etc.) in the optical axis direction L. As shown in FIG. 11, the relationship between the extended position and the drive amount obtained by integrating forward and reverse rotation drive of the drive motor 101 detected by the detection sensor 109 is rearward in the optical axis direction L as the drive amount increases. 6 in order from the retracted position shown in FIG. 6, the initial position at the time of shooting shown in FIG. 7 extended from the retracted position by a predetermined amount, and the wide angle shown in FIG. 12 and FIG. 13 extended from the initial position by a predetermined amount from the initial position. An end position and a telephoto end position are positioned.
Here, as shown in FIGS. 11, 12, and 13, the first lens group 60 is set so that the extension amount to the wide-angle end position is larger than the extension amount to the telephoto end position. .

Further, the operation timing of the barrier mechanism 120, that is, the fully closed timing at which the drive rod 122b engages with the engaging protrusion 14 and the pair of barrier blades 121 and 121 are fully closed as shown in FIGS. The fully open timing at which the drive rod 122b is disengaged from the engaging protrusion 14 and the pair of barrier blades 121 and 121 are fully opened as shown in FIGS. 7 and 9 is between the retracted position and the initial position. It is positioned.
Then, after the first lens group 60 (and the second lens group 90) reaches the initial position, the second drive mechanism 110 is driven and controlled based on the detection result of the drive amount by the first drive mechanism, and the first lens cylinder. 62 (lens G1) is moved in the optical axis direction L relative to the first lens frame 61, including a range protruding forward in the optical axis direction L from the pair of barrier blades 121, 121. Focusing (focus drive) is designed.

  As described above, the initial position at the time of photographing is positioned at a position extended forward by a predetermined amount from the retracted position in the optical axis direction L, and a pair of barrier blades is provided between the retracted position and the initial position. Since the opening and closing timings of 121 and 121 are set, a pair of barrier blades 121 and 121 is in the middle of the first lens group 60 (lens G1) and the second lens group 90 (lens G2) being extended from the retracted position to the initial position. Can be easily and reliably moved from the fully closed position to the fully open position.

  In addition, the first lens group 60 (lens G1) and the second lens group 90 (lens G2) are moved from the retracted position to the initial position at the time of shooting by the first drive mechanism, and the optical axis direction L starts from the initial position. The first lens 60 (first lens cylinder 62 (lens G1)) is moved when the first lens cylinder 62 (lens G1) is moved by the second driving mechanism 110 to perform focusing. Before reaching the initial position, the pair of barrier blades 121, 121 are moved to the fully open state, that is, when the first lens cylinder 62 (lens G1) reaches the initial position, the pair of barrier blades 121, 121 is Since the first lens cylinder 62 (lens G1) is already extended from the initial position so as to protrude from the pair of barrier blades 121, 121 because it is already fully open, 1 lens barrel 62 (lens G1) and it is possible to prevent a collision or interference of the pair of barrier blades 121, 121, it is possible to reliably ensure the intended function.

  The operation of the lens barrel will be described. Here, the detection sensor 130 detects the retracted position of the rotary cylinder 30 and the lens groups 60 and 90, the detection sensor 109 detects the drive amount of the drive unit 100 (drive motor 101), and the detection sensor 119 is the first. The rest position of the lens cylinder 62 is detected, and the control unit drives and controls the first drive mechanism (the drive motor 101 of the drive unit 100) and the second drive mechanism 110 (the drive motor 111) based on the detection results. It is like that.

First, as shown in FIGS. 3 and 6, when the first lens group 60 and the second lens group 90 (as well as the rotary cylinder 30) is in the retracted position (this position is detected by the detection sensor 130), the first The lens tube 62 is in a rest position where it is retracted from the opening 64a, and the pair of barrier blades 121, 121 are in a state in which the opening 64a is fully closed.

When the drive motor 101 is rotationally driven from this retracted position, the rotary cylinder 30 rotates through the gear train and is fed forward in the optical axis direction L, and the first lens group 60 and the second lens group 90 are also moved forward. As shown in FIG. 7, it starts to move toward the initial position at the time of shooting.
When the predetermined amount is extended, the drive rod 122b provided in the first lens group 60 is disengaged from the engaging protrusion 14 of the base 10, and the pair of barrier blades 121 and 121 are opened as shown in FIG. It moves to the fully open position (fully open state) where 64a is opened.

When the drive motor 101 is further rotated in the same direction, the first lens group 60 and the second lens group 90 (and the rotating cylinder 30) reach the initial position shown in FIG.
At this time, as shown in FIGS. 7 and 9, the pair of barrier blades 121, 121 are already fully opened, so that the first lens cylinder 62 (lens G <b> 1) is located with respect to the first lens frame 61. The pair of barrier blades 121 and 121 can be extended (protruded) forward in the optical axis direction L.

Here, whether or not the initial position has been reached (the pair of barrier blades 121 and 121 has already been fully opened) is determined (specified) by the detection sensor 109 using the first drive mechanism (the drive motor 101 of the drive unit 100). Is determined by the control unit.
Then, if it is determined that the position is at the initial position, the second drive mechanism 110 (drive motor 111) is driven and controlled by the control unit based on the detection result of the detection sensor 109, and the first lens cylinder 62 (lens G1) is controlled. ) In the optical axis direction L including a range protruding forward in the optical axis direction L from the pair of barrier blades 121 and 121 at a predetermined timing to perform focusing (focus driving).

  Further, when the drive motor 101 is driven to rotate in the same direction, the first cam cylinder 40 and the first guide cylinder 50 cause the second cam cylinder 70 to move and rotate in the optical axis direction L due to the action of the first cam cylinder 40 and the first guide cylinder 50. The lens group 60 and the second lens group 90 are cammed, and the first lens group 60 and the second lens group 90 move relative to the optical axis direction L and move to the wide-angle end position shown in FIG. Further, the zooming is performed by moving to the telephoto end position shown in FIG.

Along with this zooming, the drive motor 111 is appropriately driven to rotate, and the first lens cylinder 62 (lens G1) is connected via a gear train (drive gear 112, intermediate gear 113, driven gear 114), lead screw 115, and nut 116. As shown by a two-dot chain line in FIGS. 12 and 13, focusing is performed by moving the first lens frame 61 to a desired position in the optical axis direction L.
At this time, since the pair of barrier blades 121 and 121 are already fully opened as shown in FIGS. 9, 12 and 13, the first lens cylinder 62 (lens G1) is paired with the pair of barrier blades 121 and 121. Without being collided with or interfering with each other, it can be reliably and accurately moved to a predetermined position in the optical axis direction L.

On the other hand, when the drive motor 101 is driven to rotate in the reverse direction, the rotary cylinder 30 is retracted toward the rear in the optical axis direction L while rotating in the reverse direction via the gear train, and in conjunction with this, the first The lens group 60 and the second lens group 90 also start to retract toward the rear in the optical axis direction L.
During this retraction operation, the second drive mechanism 110 (drive) is driven based on the detection result detected by the detection sensor 109 before the first lens group 60 and the second lens group 90 (and the rotary cylinder 30) reach the initial position. The motor 111) is rotationally driven, and the first lens cylinder 62 (lens G1) is returned in advance to a rest position that is retracted rearward of the pair of barrier blades 121 and 121.

  When the drive motor 101 is further rotated in the reverse direction and the first lens group 60 and the second lens group 90 (and the rotating cylinder 30) reach a position where they are retracted by a predetermined amount from the initial position, the drive rod 122b. Begins to engage with the engaging protrusion 14 and receives a cam action, and the pair of barrier blades 121 and 121 completely opens the opening 64a as shown in FIG. 8 from the state where the opening 64a is fully opened as shown in FIG. The closed state is reached.

  Further, when the drive motor 101 is rotationally driven in the reverse direction, the first lens group 60 and the second lens group 90 (and the rotary cylinder 30) reach the retracted position, and at the same time, based on the detection signal of the detection sensor 130, The control unit stops the drive control of the drive unit 100 (the drive motor 101).

  Thus, according to the lens barrel configured as described above, the first lens group 60 (lens G1) and the second lens group 90 (lens G2) are moved from the retracted position to the initial position at the time of photographing by the first driving mechanism. When moved to the initial position, the pair of barrier blades 121 and 121 are already in the fully open state, so that the first lens cylinder 62 (lens G1) protrudes more than the pair of barrier blades 121 and 121. Even when the lens is extended from the position, the collision or interference between the first lens barrel 62 (lens G1) and the barrier blade 121 can be prevented, and the intended function can be reliably ensured.

In the above embodiment, the case where the barrier mechanism 120 includes a pair of barrier blades 121 and 121 has been described. However, the present invention is not limited to this, and one barrier blade, or three or more barrier blades are included. You may employ | adopt the structure containing.
In the above embodiment, the two lens groups 60 and 90 are shown as the lens group moving in the optical axis direction L. However, the present invention is adopted in a configuration including one lens group or three or more lens groups. May be.
In the above embodiment, the case where the barrier mechanism 120 opens and closes the pair of barrier blades 121 and 121 in conjunction with the movement of the first lens group 60 (the first lens frame 61) has been described. However, the present invention may be employed in a configuration that employs a dedicated drive mechanism that is driven and controlled by the control unit without adopting a mechanical interlocking relationship, and opens and closes the barrier blades at a predetermined timing.

  As described above, the lens barrel of the present invention has a barrier mechanism (barrier blade) in a configuration having a barrier mechanism while achieving simplification of the structure, reduction in the number of parts, miniaturization, thinning, and the like. Cameras can be applied as lens barrels for thin digital cameras, thin silver film cameras, etc., because they can reliably prevent lens collision or interference and ensure the desired functions. The lens barrel is not limited to the lens barrel of other lens optical systems that are desired to be thin.

It is a front view which shows one Embodiment of the lens barrel which concerns on this invention. It is sectional drawing in a surface perpendicular | vertical to the optical axis of the lens barrel shown in FIG. It is sectional drawing in the surface containing the optical axis of the lens barrel shown in FIG.1 and FIG.2. FIG. 3 is a developed cross-sectional view of a lens barrel shown in FIGS. 1 and 2 including a surface including an optical axis. FIG. 3 is a developed cross-sectional view of a lens barrel shown in FIGS. 1 and 2 including a surface including an optical axis. It is sectional drawing in the surface containing the optical axis in the retracted position of the lens barrel shown in FIG.1 and FIG.2. It is sectional drawing in the surface containing the optical axis in the initial position of the lens barrel shown in FIG.1 and FIG.2. It is a partial front view which shows the fully closed state of the barrier mechanism which makes a part of lens barrel. It is a partial front view which shows the fully open state of the barrier mechanism which makes a part of lens barrel. It is a fragmentary sectional view which shows a part of barrier mechanism which makes a part of lens barrel. It is a graph which shows the relationship between the drive amount of a lens barrel, and a feeding position. 8 is a cross-sectional view showing a state where the lens is in a wide-angle end position in the lens barrel shown in FIGS. 8 is a cross-sectional view showing a state where the lens is in a telephoto end position in the lens barrel shown in FIGS.

Explanation of symbols

L Optical axis direction 10 Base 20 Fixed cylinder 22 Cylindrical part 22a Notch part 22b Cam groove 22c Guide groove 30 Rotating cylinder 31 Follower pin 32 Teeth row 40 First cam cylinder (first drive mechanism)
41 Protrusion 42 Penetration cam 43 Guide groove 50 First guide tube 51 Arc-shaped slot 52 Protrusion 53 Guide groove 60 First lens group G1 Lens 61 First lens frame 62 First lens tube 63 Outer cylindrical part (first lens frame)
63a Notch 63b Protrusion 63c Follower pin 64 Inner cylindrical part (first lens frame)
64a Opening 65 Front end wall (first lens frame)
70 Second cam cylinder (first drive mechanism)
71 follower pin 72 outer cam groove 73 inner cam groove 80 second guide tube 90 second lens group G2 lens 93 follower pin 100 drive unit (first drive mechanism)
Reference Signs List 101 drive motor 109 detection sensor 110 second drive mechanism 111 drive motor 119 detection sensor 120 barrier mechanism 121 barrier blade 122 drive lever 122a drive pin 122b drive rod 123, 124 torsion spring 130 detection sensor

Claims (3)

A first lens frame, a first lens cylinder that is supported movably in the optical axis direction with respect to the first lens frame and that holds the lens, and is disposed in front of the lens in the optical axis direction to open and close the opening. A first lens group including a barrier blade supported to be openable and closable with respect to the first lens frame;
A second lens group arranged behind the first lens group in the optical axis direction;
A first drive mechanism for moving the first lens group and the second lens group in the direction of the optical axis and opening and closing the barrier blades in accordance with the movement;
A second drive mechanism provided in the first lens frame for moving the first lens cylinder in the optical axis direction including a range protruding forward in the optical axis direction from the barrier blade during photographing;
A lens barrel including a control means for driving and controlling the first drive mechanism and the second drive mechanism,
In the process of bringing the first lens group and the second lens group from the retracted position to the initial position at the time of photographing, the control means moves the first lens cylinder from the barrier blade after the barrier blade is fully opened. The first lens cylinder in the process of extending the first lens group and the second lens group from the extended position to the retracted position from the extended position through the initial position in order to extend from the rest position retracted rearward in the optical axis direction. To drive the second drive mechanism based on the detection result of the drive amount of the first drive mechanism in order to bring the barrier blades into a fully closed state after being brought into the rest position.
A lens barrel characterized by that. The initial position is positioned at a position extended forward by a predetermined amount from the retracted position in the optical axis direction.
The lens barrel according to claim 1. The barrier blade is formed to be opened and closed in conjunction with the movement of the first lens frame.
The lens barrel according to claim 1, wherein the lens barrel is provided.

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