JP2008256988A - Lens barrel and camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel that can be made smaller. <P>SOLUTION: The lens barrel includes, on a first face 6a, a first zone Z1 having a first lead female helicoid 18a with a first lead, and second zones Z2 and Z3 having second lead female helicoids 18b and 18c with a second lead smaller than the first lead. A second helicoid 24 is a projecting portion of predetermined height h, which is formed on a second face 21a. The second helicoid 24 has, at both ends, end faces 30a and 30b and 40a and 40b that include sides which are parallel to the first lead female helicoid 18a, and grooves 25 formed parallel to the second lead female helicoids 18b and 18c along its length and are shallower than the predetermined height h. In the first zone Z1, the end faces 30a and 30b and 40a and 40b of the second helicoid 24 are engaged with the first lead female helicoid 18a. Consequently, in the zones Z2 and Z3, the groove 25 of the second helicoid 24 helically is engaged with the second lead female helicoids 18b and 18c. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lens barrel and a camera having a helicoid structure.

Conventionally, there is a lens barrel in which one cylinder is extended from the other cylinder by the action of a helicoid while relatively rotating two cylinders. Further, in such a lens barrel, there is a lens barrel in which a plurality of regions having different helicoid leads are provided in one cylindrical body, and the feeding speed with respect to the rotation angle is adjusted. With the recent miniaturization of cameras, lens barrels have also been miniaturized, and various methods for miniaturizing such a helicoid structure have been proposed (see, for example, Patent Document 1).
JP 2006-113418 A

  However, when the lens barrel is reduced in size or thickness, it is not easy to reliably screw the lens barrel while maintaining a sufficient sliding contact area between the helicoids in any region.

  An object of the present invention is to provide a lens barrel having a helicoid structure that can be surely screwed while maintaining a sufficient sliding contact area even when it is downsized or thinned.

  The present invention solves the problem by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.

The lens barrel according to claim 1 is opposed to the first cylinder (6) having the first helicoid (18) provided on the first surface (6a) and the first surface (6a). A lens barrel (1) having a second cylinder (21) provided with a second helicoid (24) on a second surface (21a), wherein the first cylinder (6) The first surface (6a) has a first region (Z1) provided with a first lead helicoid (18a) having a first lead, and a second lead smaller than the first lead. And a second region (Z2, Z3) provided with a second lead helicoid (18b, 18c) having the second helicoid (24) provided on the second surface (21a). A projecting portion having a height (h), which is unfolded on a plane and has first lead helicoids at both ends. 18a) having end faces (30a, 30b, 40a, 40b) parallel to the second lead helicoids (18b, 18c) and shallower than the predetermined height (h) (25), In the first region (Z1), the end surface (30a, 30b, 40a, 40b) of the second helicoid (24) and the first lead helicoid (18a) are screwed together, and the second region (Z2, In the lens barrel (1), the groove (25) of the second helicoid (24) and the second lead helicoid (18b, 18c) are screwed together in Z3).
The lens barrel according to claim 2 is the lens barrel (1) according to claim 1, wherein the second helicoids (24) are alternately arranged second helicoids A (24a). And the second helicoid B (24b), and the second helicoid A (24) and the second helicoid B (24) are arranged in a point-symmetric manner in a state where they are deployed on a plane. Each of which is a polygonal shape having at least three sets of two sides parallel to each other, and the three sets of two sides parallel to each other are parallel to the first lead female helicoid (18a) (30a, 30b, 40a, 40b), two parallel sides, two sides parallel to the groove (25), a subject side side parallel to the edge of the first cylinder (6), and The second helicoid A ( 4a), the groove (25) extends between the side on the subject side and the end face (30b) in a state of being developed in a plane, and in the second helicoid B (24b), the groove (25) The lens barrel (1) is characterized by extending between the end face (40a) and the image-side edge in a state of being developed on a plane.
The lens barrel according to claim 3 is the lens barrel (1) according to claim 2, wherein the second lead female helicoid (18b, 18c) is the first lead female helicoid (18a). A second lead helicoid A (18ba, 18ca) having an end on the extension line, and a second lead helicoid B (18bb, 18cb) extending further across the extension line of the first lead female helicoid (18a); These are lens barrels (1) characterized by having alternately.
The lens barrel according to claim 4 is the lens barrel (1) according to claim 2 or 3, wherein the second region (Z2, Z3) is in a wide state with the retracted region (Z3). And the wide-tele area (Z2) moving between the tele state and the tele area, the first area (Z1) includes the retracted area (Z3) and the wide-tele area (Z2). It is a lens barrel (1) characterized by being a feeding region (Z1) between the two.
The lens barrel according to claim 5 is the lens barrel (1) according to claim 4, wherein the first lens barrel (1) is moved from the extended region (Z1) to the wide-tele region (Z2). A two-lead helicoid A (18ba) advances from the end face (40a) of the second helicoid B (24b) toward the image-side side and proceeds to the groove (25), and the second lead helicoid B (18bb) The lens barrel (1) is characterized in that the second helicoid A (24a) advances through the groove (25) from the side on the subject side toward the end face (30b).
The lens barrel according to claim 6 is the lens barrel (1) according to claim 4, wherein the second lead is formed when the lens barrel (1) is moved from the extension region (Z1) to the retracted region (Z3). The helicoid A (18ca) advances from the end surface (30b) of the second helicoid A (24a) toward the subject side, and the second lead helicoid B (18cb) The lens barrel (1) is characterized in that the groove (25) advances from the image-side edge of the second helicoid B (24b) toward the end face (40a).
The camera of Claim 7 is a camera (2) provided with the lens-barrel (1) of any one of Claims 1-6.

  Note that the configuration described with reference numerals may be modified as appropriate, and at least a part of the configuration may be replaced with another component. Further, in the present application, for ease of explanation, various helicoids are described as shapes on a development view when a cylinder provided with the helicoid is developed. However, actually, the helicoid is formed on the cylindrical surface, and even if it is described as a shape on the development view, the helicoid in the present application means a helicoid provided on the cylindrical surface.

  According to the present invention, it is possible to provide a lens barrel having a helicoid structure that can be reliably screwed while maintaining a sufficient slidable contact area even when it is downsized or thinned.

  Hereinafter, a lens barrel according to an embodiment of the present invention will be described with reference to the drawings. In each figure, the direction toward the subject along the optical axis A is the z plus direction. The lens barrel of the present embodiment is, for example, a collapsible lens barrel whose total length in the optical axis direction changes between shooting and non-shooting.

  First, the overall configuration of the lens barrel 1 will be described. 1 to 3 are views showing the lens barrel 1. FIG. 1 is a sectional view of the lens barrel 1 in the retracted state, FIG. 2 is a sectional view of the lens barrel 1 in the wide state, and FIG. FIG. 2 is a cross-sectional view of a tube 1 in a tele state.

  The lens barrel 1 includes a first lens unit L1, a second lens unit L2, a third lens unit L3, a fourth lens unit L4, and an image side end of the lens barrel 1 that form a zoom lens having a four-group configuration. A CCD base 3 fixed to the main body of the camera 2 and a CCD 4 arranged at the center thereof, a fixed cylinder 6 fixed to the CCD base 3, and a movable cylinder that can be extended from the fixed cylinder 6 to the subject side. 721, 22, 23. The lens barrel 1 further holds the first holding unit 11 that holds the first lens group L1, the second holding unit 12 that holds the second lens group L2, and the third lens group L3. A third holding unit 13 and a fourth holding unit 14 holding the fourth lens group are provided.

  The first lens group L1, the second lens group L2, the third lens group L3, and the fourth lens group L4 form a four-group zoom lens as described above. 2 and 3, when the lens groups L1 to L4 are extended, the first lens group L1, the second lens group L2, the third lens group L3, and the image side move from the subject side to the image side in the optical axis A direction. They are arranged in the order of the fourth lens unit L4. In the retracted state in FIG. 1, the third lens unit L3 is retracted from the optical axis A to substantially the same position as the fourth lens unit L4.

  The CCD table 3 disposed at the image side end of the lens barrel 1 is a substantially disk-shaped member that holds the CCD 4 at a substantially central portion. The CCD 4 is an optical-electrical conversion element that converts subject light that has passed through the lens groups L1 to L4 into an electrical signal. The CCD 4 is disposed on the emission side of the fourth lens unit L4, and a low-pass filter LPF 16 for reducing moire is provided between the CCD 4 and the fourth lens unit L4.

  The fixed cylinder 6 is a cylinder whose image side end is fixed to the CCD table 3. A female helicoid 18 to be described later is provided on the inner peripheral surface 6 a of the fixed cylinder 6, and a gear 19 connected to a drive source (not shown) is disposed in a part of the fixed cylinder 6.

  The moving cylinder 7 has a first moving cylinder 21, a second moving cylinder 22, and a third moving cylinder 23 that can be fed out from the fixed cylinder 6. The first moving cylinder 21 is housed on the inner diameter side of the fixed cylinder 6, and obtains a rotational force by the gear 19 rotated by the drive source (not shown) described above, so that the first moving cylinder 21 moves in the optical axis A direction with respect to the fixed cylinder 6. A cylinder to be driven. A male helicoid 24 described later is provided on the outer peripheral surface 21 a of the first moving cylinder 21. The second moving cylinder 22 is a cylinder housed on the inner diameter side of the first moving cylinder 21, and can advance and retract in the optical axis direction with respect to the first moving cylinder 21. The third moving cylinder 23 is a cylinder housed on the inner diameter side of the second moving cylinder 22, and can move back and forth in the optical axis direction with respect to the second moving cylinder 22.

  The first holding unit 11 is an annular frame that holds the first lens unit L1 on its inner diameter side, and is provided in the vicinity of the end of the third moving cylinder 23 on the subject side in the optical axis direction. The second holding portion 12 is a portion that supports the second lens group L <b> 2 and is inserted on the inner diameter side of the third moving cylinder 23. The second holding unit 12 drives the second lens unit L2 in a plane orthogonal to the optical axis A in accordance with known image blur correction control, and reduces image blur of an image formed on the imaging surface of the CCD 4. An image blur correction device (not shown) is provided. The third holding unit 13 supports the third lens group L3.

  Next, the female helicoid 18 will be described in detail. FIG. 4 is a perspective view of the female helicoid 18 viewed from the outside with the fixed cylinder 6 unfolded. For convenience of explanation, the female helicoid 18 is indicated by a solid line. In the figure, the upper z plus side is the subject side, and the lower z minus side is the image side. In the following, the shapes of the female helicoid 18 and the male helicoid 24 will be described in order to facilitate the description unless particularly limited. However, in actuality, the female helicoid 18 and the male helicoid 24 are cylindrical surfaces. Formed on top.

  The fixed cylinder 6 has a feeding area Z1 in which a first lead female helicoid 18a having a first lead is provided at the center of the inner peripheral surface 6a, and a second area which is located on the subject side and which is smaller than the first lead. A wide-tele area Z2 provided with a second lead female helicoid 18b having the same lead, and a second lead smaller than the first lead, which is located on the image side of the feeding area Z1, as in the wide-tele area Z2. A retractable region Z3 provided with a third lead female helicoid 18c. In any region, six female helicoids 18 are provided.

  The first lead female helicoid 18a in the feeding area Z1 has a long female helicoid 18aa and a short female helicoid 18ab which are provided at intervals of 60 degrees in the circumferential direction and slightly different in length every other line. The second lead female helicoid 18b in the wide-tele region Z2 intersects the second lead female helicoid 18ba having an end on the extension line p of the first lead female helicoid 18a and the extension line q of the first lead female helicoid 18a. And a second lead female helicoid 18bb extending further toward the feeding region Z1 side than the extension line q. The third lead female helicoid 18c in the retracted region Z3 also intersects the third lead female helicoid 18ca having an end on the extension line p of the first lead female helicoid 18a and the extension line q of the first lead female helicoid 18a. Furthermore, it has the 3rd lead female helicoid 18cb extended. The first lead female helicoid 18a has a first height protruding from the inner peripheral surface 6a to the inner diameter side, and the second lead female helicoid 18b and the third lead female helicoid 18c are lower than the first height. It has a height of 2.

  A rib portion 28 is formed along the edge of the fixed cylinder 6 on the z plus side of the inner peripheral surface 6a of the fixed cylinder 6 in the subject side view. The z plus side of the second lead female helicoid 18b in the subject side view is formed along the rib portion 28 thereof.

  Next, the male helicoid 24 will be described in detail. FIG. 5 is a diagram in the retracted state showing the male helicoid 24 in a state of being screwed with the female helicoid 18. Six male helicoids 24 are provided so as to have an interval of 60 degrees in the circumferential direction. The six male helicoids 24 are composed of male helicoid 24a and male helicoid 24b arranged alternately, and male helicoid 24a and male helicoid 24b have the same shape and are arranged point-symmetrically with respect to each other.

  6 is a cross-sectional view of the male helicoid 24 taken along the line VI-VI in FIG. As illustrated, the male helicoid 24 is a protruding portion having a predetermined height h. As shown in FIGS. 5 and 6, the male helicoid 24 is parallel to the second lead female helicoid 18b and the third lead female helicoid 18c in the wide-tele area Z2 and the retracted area Z3, and is more than a predetermined height h. A groove 25 having a shallow depth d is provided. Further, end faces 30a, 30b, 40a, 40b parallel to the first lead female helicoid 18a in the feeding area Z1 are provided at both ends in the longitudinal direction. Further, two side surfaces 31a, 31b, 41a, 41b parallel to the groove 25 are provided. Furthermore, a subject-side side surface 32a and an image-side side surface 32b that are parallel to the rib portion 28, and a subject-side side surface 42a and an image-side side surface 42b are provided. In the male helicoid 24a, the groove 25 extends between the subject side surface 32a and the end surface 30b. Further, in the male helicoid 24b, the groove 25 extends between the end surface 40a and the image side surface 42b. Further, the distal end of the male helicoid 24a on the subject side surface 32a side and the distal end of the male helicoid 24b on the image side end surface 42b side are cut to the same depth as the groove 25 to form a female helicoid introduction portion 33.

  Note that there is a slight gap between the image side surface 41b parallel to the second lead female helicoid 18c and the second lead female helicoid 18cb in the male helicoid 24b, and there is no contact. Thereby, the dimensional accuracy of the male helicoid 24 is relaxed.

  Next, the operation of the lens barrel 1 will be described. As shown in FIG. 5, in the retracted state, the third lead female helicoid 18ca is inserted into the groove 25 of the male helicoid 24a. A third lead female helicoid 18cb is inserted into the groove 25 of the male helicoid 24b.

  When a power switch (not shown) is turned on in the retracted state, the gear 19 shown in FIG. 1 is rotated by the drive source. Then, the first moving cylinder 21 starts to rotate with respect to the fixed cylinder 6. FIG. 7 is a diagram showing a screwed state of the first lead female helicoid 18a and the male helicoid 24 in the extended region Z1 in the middle of the lens barrel 1 being extended from the retracted state to the wide position. FIG. 8 is a perspective view thereof. As shown in the drawing, the male helicoids 24a and 24b are respectively guided at the end surfaces 30a, 30b, 40a and 40b by the side surfaces 35 of the first lead female helicoid 18a.

  At this time, the groove 25 is provided in the male helicoid 24. As shown in FIG. 6, the groove 25 has a depth d shallower than the height h of the protruding portion of the male helicoid 24. For example, as in the comparative example shown in FIG. 9, when the depth of the groove 25 ′ is the same as the height h, the area in sliding contact with the side surface 35 of the female helicoid 18 a is only the cross-sectional area of the two protrusions having the depth h. However, in the case of the present embodiment, the width is increased by an amount substantially corresponding to the area obtained by multiplying the width of the groove 25 by the length obtained by subtracting d from h. Thus, according to this embodiment, since the area of end surface 30a, 30b, 40a, 40b is large compared with a comparative example, a big sliding contact area is securable. Therefore, reliable and stable sliding is ensured. Moreover, there is little decrease in the dimension of the distance between the end faces 30a and 30b, 40a and 40b due to wear, and the durability is improved.

  Then, the end surfaces 30 a, 30 b, 40 a, 40 b of the male helicoid 24 slide on the side surface 35 of the first lead female helicoid 18 a, and the rotation of the first moving cylinder 21 causes the first moving cylinder 21 to move relative to the fixed cylinder 6. It moves out in the z direction in the subject direction diagram. At this time, in the feeding area Z1, the first lead of the first lead female helicoid 18a is larger than the second lead of the third lead female helicoid 18c in the retracted area Z3. The feeding amount of the helicoid 24 is larger than the retracted region Z3.

  10 is a view showing a screwed state of the second lead female helicoid 18b and the male helicoid 24 in the wide state shown in FIG. 2, and FIG. 11 is a perspective view thereof. As shown in the drawing, the male helicoid 24a moves so that the second lead female helicoid 18bb enters the groove 25. At this time, since the female helicoid introduction portion 33 is provided on the subject side surface 32a of the male helicoid 24a, the second lead female helicoid 18bb easily enters the groove 25. Further, the male helicoid 24b moves so that the groove 25 enters the second lead female helicoid 18ba.

  At this time, the groove 25 of the male helicoid 24 is d shallower than the height h of the male helicoid 24, and the height of the second lead female helicoid 18b is also low, but unlike the first region Z1, between the wide-tele Since the male helicoid 24 is guided in a long range between the side surface of the groove 25 and the side surface of the second lead female helicoid 18b, the male helicoid 24 is reliably and stably guided even if the engagement is shallow. Also in this case, there is a slight gap between the subject side surface 31a parallel to the second lead female helicoid 18b and the second lead female helicoid 18ba in the male helicoid 24a, and there is no contact.

  12 is a view showing a screwed state between the second lead female helicoid 18b and the male helicoid 24 in the tele state shown in FIG. As shown in the drawing, the second lead female helicoid 18bb and the second lead female helicoid 18ba enter the groove 25, and the female helicoid 18 and the male helicoid 24 are securely screwed together. It should be noted that in the male helicoid 24a, between the subject side surface 31a parallel to the second lead female helicoid 18b and the second lead female helicoid 18ba, and to the image side side surface 41b parallel to the second lead female helicoid 18b of the male helicoid 24b. There is a slight gap between the two-lead female helicoid 18bb and there is no contact.

As described above, this embodiment has the following effects.
(1) The male helicoid 24 has a groove 25, and the groove 25 is shallower than the height h of the male helicoid 24. Therefore, the area where the end surfaces 30a, 30b, 40a, 40b of the male helicoid 24 are in sliding contact with the female helicoid 18 can be increased, and the female helicoid 18 and the male helicoid 24 are reliably and stably screwed in the feeding region Z1. be able to.
(2) Since the female helicoids 18 are extended every other in the wide-tele area Z2 and the retracted area Z3 toward the feeding area Z1, the movement of the male helicoid 24 between areas where the leads of the female helicoid 18 are different is performed smoothly.

Modifications As described above, various modifications and changes are possible without being limited to the embodiments described above, and these are also within the scope of the present invention.
(1) In the present embodiment, the female helicoid and the male helicoid have a six-row configuration, but the present invention is not limited to this. It may be other articles below or above.
(2) In this embodiment, the male helicoid 24 is point-symmetric with respect to the male helicoids 24a and 24b adjacent to each other. However, the present invention is not limited to this. Not necessarily.
(3) In this embodiment, the female helicoid 18 is formed on the inner peripheral surface 6a of the fixed cylinder 6 and the male helicoid 24 is formed on the outer peripheral surface 21a of the first movable cylinder 21, but this is not a limitation. The helicoid 18 can also be formed on the moving cylinder.

It is sectional drawing in the retracted state of the lens-barrel of embodiment of this invention. It is sectional drawing in the wide state of the lens-barrel of embodiment of this invention. It is sectional drawing in the tele state of the lens-barrel of embodiment of this invention. It is an expanded view of the internal peripheral surface of the fixed cylinder provided with the female helicoid. It is the figure which showed the screwing state of the female helicoid and the male helicoid in the retracted state. It is sectional drawing along the VI-VI line of the male helicoid in FIG. It is the figure which showed the screwing state of the female helicoid and the male helicoid in a feeding area | region. It is a perspective view of the state of FIG. It is the figure which showed the comparative example with respect to FIG. It is a figure which shows the screwing state of the female helicoid and a male helicoid in a wide state. It is a perspective view of the state of FIG. It is the figure which showed the screwing state of the female helicoid and the male helicoid in the tele state.

Explanation of symbols

  1: lens barrel, 6: fixed cylinder, 6a: inner peripheral surface, 18: female helicoid, 21: first moving cylinder, 21a: outer peripheral surface, 24: male helicoid, 25: long female helicoid, 26: short female Helicoid, Z1: extended area, Z2: wide-tele area, Z3: retracted area

Claims (7)

A first cylinder provided with a first helicoid on a first surface;
A second cylinder having a second helicoid provided on a second surface facing the first surface;
A lens barrel comprising:
The first cylindrical body has a first region provided with a first lead helicoid having a first lead on the first surface, and a second region having a second lead smaller than the first lead. A second region provided with a lead helicoid,
The second helicoid is a projecting portion having a predetermined height provided on the second surface, and in an unfolded state on a plane, end surfaces parallel to the first lead helicoid at both ends, and the first helicoid A groove parallel to the two-lead helicoid and shallower than the predetermined height;
In the first region, the end face of the second helicoid and the first lead helicoid are screwed together,
The lens barrel, wherein the groove of the second helicoid and the second lead helicoid are screwed in the second region. The lens barrel according to claim 1,
The second helicoid is composed of alternately arranged second helicoid A and second helicoid B;
The second helicoid A and the second helicoid B are of the same shape and arranged symmetrically with respect to each other in a state of being developed on a plane, and each has at least three sets of two sides parallel to each other. Polygonal shape,
The three sets of two parallel sides are
Two parallel sides constituting the end face parallel to the first lead helicoid;
Two sides parallel to the groove;
A side on the subject side and a side on the image side parallel to the edge of the first cylindrical body,
In the second helicoid A, the groove extends between the side on the subject side and the end surface in a state of being developed on a plane,
In the second helicoid B, the groove extends between the end face and the image side in a state where the groove is developed on a plane. The lens barrel according to claim 2,
The second lead helicoid is
A second lead helicoid A having an end on an extension of the first lead helicoid;
A lens barrel characterized by alternately having second lead helicoids B that cross and extend the extension lines of the first lead helicoids. The lens barrel according to claim 2 or 3,
The second region is two regions of a retracted region and a wide-tele region that moves between a wide state and a tele state,
The lens barrel according to claim 1, wherein the first region is a feeding region between the retracted region and the wide-tele region. The lens barrel according to claim 4,
When shifting from the payout area to the wide-tele area,
The second lead helicoid A advances through the groove from the end face of the second helicoid B toward the image side,
The lens barrel, wherein the second lead helicoid B advances in the groove from the side of the subject side of the second helicoid A toward the end surface. The lens barrel according to claim 4,
When transitioning from the feeding area to the retracted area,
The second lead helicoid A travels through the groove from the end face of the second helicoid A toward the subject side,
The lens barrel, wherein the second lead helicoid B advances in the groove from the image-side side of the second helicoid B toward the end surface.   A camera provided with the lens barrel of any one of Claims 1-6.

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