JP2010078958A - Lens barrel and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a more compact lens barrel having three reflecting surfaces, configured so that an optical axis of light reflected by a reflecting member arranged closest to the object side may be parallel to an optical axis of light reflected by a reflecting member arranged closest to the image side, and to obtain an imaging apparatus. <P>SOLUTION: In the lens barrel, the reflecting member disposed closest to the object side is arranged at the inside of the outside surface facing the reflecting surface arranged closest to the image side, of the imaging element. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lens barrel including a bending optical system in which three reflecting surfaces are arranged in an optical system, and an imaging apparatus including the lens barrel.

  Conventionally, a camera equipped with an imaging optical system (for example, a zoom lens) capable of zooming is commercially available. The zoom lens is configured to change a focal length (zooming) by moving a plurality of lens groups constituting an optical system to a desired position along an optical axis and changing an interval therebetween.

  In recent years, cameras using a so-called bending optical system in which a reflecting surface is arranged in an imaging optical system capable of zooming and the optical axis is bent are increasing. A camera using this bending optical system has the advantage that the lens barrel does not protrude from the front of the camera during shooting and the form of the camera does not change even when zooming is performed.

As such a lens barrel including a bending optical system, the reflecting member has three reflecting surfaces and is reflected by the reflecting member disposed closest to the object side and disposed closest to the image surface side. There is known a lens barrel that is arranged so that the optical axis after reflection at is parallel (see, for example, Patent Document 1).
JP 2007-133214 A

  The lens barrel described in Patent Document 1 is a lens barrel capable of high zooming while achieving a small size and thickness. However, the outer shape of an imaging device represented by a camera is generally a rectangular parallelepiped shape, and when a built-in lens barrel has a protruding portion, the imaging device such as a rectangular parallelepiped camera is included to include the protruding portion. There is a problem that the outer shape becomes larger.

  In view of the above problems, the present invention has three reflection surfaces, and the light axis after reflection by the reflection member arranged closest to the object side and the light after reflection by the reflection member arranged closest to the image surface side. An object of the present invention is to obtain a lens barrel and an imaging device that are further downsized in a lens barrel that is arranged so that its axis is parallel.

  The above object is achieved by the invention described below.

  (1) A plurality of lens groups, and a first reflecting surface, a second reflecting surface, a third reflecting surface, and a rear side of the third reflecting surface in order from the object side between the lens groups. And a lens arranged so that an optical axis after being reflected by the first reflecting surface and an optical axis after being reflected by the third reflecting surface are parallel to each other. In the lens barrel, the lens mirror is characterized in that the reflecting member having the first reflecting surface is arranged closer to the second reflecting surface than the outer surface facing the third reflecting surface of the imaging element. Torso.

  (2) One of a light amount regulating member and a shutter is disposed between the first reflecting surface and the second reflecting surface, and the light amount is regulated between the third reflecting surface and the imaging surface of the imaging element. The lens barrel according to (1), wherein the other of the member and the shutter is disposed.

  (3) Formation of a cam groove that rotates in a plane parallel to a plane including the optical axis after being reflected by the first reflecting surface and the optical axis after being reflected by the third reflecting surface The lens barrel according to (1) or (2), wherein the lens barrel includes a plate-like rotation member that is moved, and the lens group is moved by rotation of the rotation member.

  (4) The cam groove of the rotating member is formed between the lens group disposed between the first reflecting surface and the second reflecting surface, the third reflecting surface, and the imaging surface of the imaging element. The lens barrel according to any one of (1) to (3), wherein the lens barrel is engaged with a pin formed on a lens frame that holds the arranged lens group.

  (5) The lens barrel according to any one of (1) to (4), wherein at least a moving lens group among the plurality of lens groups is supported by two guide shafts.

  (6) The lens barrel according to any one of (1) to (5), wherein a drive unit is arranged on a slope formed by the second reflecting surface or the third reflecting surface.

  (7) An imaging apparatus comprising the lens barrel according to any one of (1) to (6).

  According to the present invention, there are three reflecting surfaces, and the optical axis after reflection by the reflecting member arranged closest to the object side and the optical axis after reflection by the reflecting member arranged closest to the image plane side are: Even in a lens barrel arranged so as to be parallel, it is possible to obtain a more compact lens barrel and imaging device.

  Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not limited thereto.

  FIG. 1 is a diagram illustrating an example of an internal arrangement of main constituent units of a camera 100 which is an example of an imaging apparatus including a lens barrel according to the present embodiment. FIG. 2 is a perspective view of the camera 100 as viewed from obliquely above the subject side.

  As shown in the figure, in the camera 100, a lens barrel 50 including a foldable imaging optical system capable of zooming is arranged vertically on the right side as shown in the figure, and an opening 51 is arranged so as to take in a subject light beam. . The opening 51 is provided with a lens barrier (not shown) that is in an open state that exposes the opening 51 and a closed state that covers the opening 51.

  Reference numeral 52 denotes a flash light emission window. Reference numeral 53 denotes a flash unit including a reflector, a xenon tube, other main capacitors, a circuit board, and the like disposed behind the flash light emission window. Reference numeral 54 denotes a card-type image recording memory. A battery 55 supplies power to each part of the camera. The image recording memory 54 and the battery 55 can be inserted and removed from a lid (not shown).

  A release button 56 is arranged on the upper surface of the camera 100. When the first button is pressed, a shooting preparation operation of the camera, that is, a focusing operation and a photometric operation are performed, and a shooting exposure operation is performed by pressing the second button. A main switch 57 is a switch for switching the camera between an operating state and a non-operating state. When switched to the operating state by the main switch 57, the lens barrier (not shown) is opened and the operation of each part is started. When the main switch 57 is switched to the non-operating state, the lens barrier (not shown) is closed and the operation of each unit is ended.

  On the back surface of the camera 100, an image display unit 58 that is configured by an LCD, an organic EL, or the like and displays an image, other character information, or the like is disposed. Although not shown, a zoom button for zooming up and down, a playback button for playing back a captured image, a menu button for displaying various menus on the image display unit 58, and a desired function are selected from the display. An operation member such as a selection button is arranged.

  Although not shown, a circuit board on which various electronic components are mounted is arranged between these main constituent units, and each main constituent unit is driven and controlled. Yes. Similarly, an external input / output terminal, a strap attaching portion, a tripod seat, etc., not shown, are provided.

  FIG. 2 is a schematic cross-sectional view showing a schematic structure inside the lens barrel 50 according to the present embodiment.

  The lens barrel 50 shown in FIG. 2 includes a reflecting member 101 having a reflecting surface (first reflecting surface) R1 that bends an optical axis OA perpendicular to the paper surface from the subject side to an optical axis OB parallel to the paper surface. Has been placed. Furthermore, a reflection surface (second reflection surface) R2 for bending the optical axis OB in the optical axis OC direction and a reflection surface (third reflection surface) R3 for bending the optical axis OC in the optical axis OD direction are provided. Yes. The optical axis OB and the optical axis OD are arranged in parallel. In the example of this drawing, the second reflecting surface R2 and the third reflecting surface R3 are configured by the integral reflecting member 102, but may be configured separately.

  The first lens group 1 is disposed before and after the reflecting member 101 having the first reflecting surface R1. The first lens group 1 includes a lens group 1a (shown by a broken line) arranged in front of the reflecting member 101 (subject side) and a lens group 1b arranged in the rear (image plane side) of the reflecting member 101. ing.

  Further, on the optical axis OB, the second lens group 2 and the third lens group 3 are disposed on the image plane side of the lens group 1b, and the second reflection surface R2 and the third reflection surface R3 are interposed therebetween. A fourth lens group 4, a fifth lens group 5, and a sixth lens group 6 are disposed on the optical axis OD. An optical filter 7 and an image sensor 8 are disposed on the image plane side of the sixth lens group 6. The optical filter 7 is an infrared light cut filter or a filter in which an infrared light cut filter and an optical low-pass filter are stacked.

  The first lens group 1, the third lens group 3, and the sixth lens group 6 are held by the main body 10. On the other hand, the second lens group 2 and the fourth lens group 4 are held by an integral lens frame 24k as shown in the figure, and the fifth lens group 5 is held by a lens frame 5k. The lens frame 24k and the lens frame 5k are guided by the two guide shafts 11 and 12, respectively, and are slidable in the optical axis direction.

  An ND filter 15 that is a light amount regulating member is disposed between the third lens group 3 and the reflecting member 102, and can be inserted into and removed from the optical path by the rotation of the motor 31. A shutter 16 is disposed between the fourth lens group 4 and the reflecting member 102, and the shutter can be opened and closed by the rotation of the motor 32.

  Note that a configuration in which the shutter 16 is disposed between the third lens group 3 and the reflecting member 102 and the ND filter 15 is disposed between the fourth lens group 4 and the reflecting member 102 may be employed. Further, a mechanical aperture may be used as the light quantity regulating member.

  Further, as shown in the drawing, it is preferable that the light quantity regulating member, the shutter and the motors 31 and 32 are assembled to the shutter case 23 to form a unit and be integrated. By doing so, the lens barrel 50 can be manufactured at a low cost by reducing the number of assembly steps.

  The lens frame 24k that integrally holds the second lens group 2 and the fourth lens group 4 is guided to the guide shafts 11 and 12 by the rotation of a plate-shaped rotating member in which a cam groove (not shown) is formed. Thus, it can be moved in the optical axis direction.

  A female screw member 5 s is engaged with the lens frame 5 k that holds the fifth lens group 5, and is screwed into a lead screw 25 r that is driven by the stepping motor 25. The female screw member 5s is moved by the rotation of the lead screw 25r, and the lens barrel 5k to be engaged is guided by the guide shafts 11 and 12 and moved in the optical axis direction.

  Furthermore, the reflecting member 101 having the first reflecting surface R1 is disposed on the second reflecting surface R2 side from the outer surface facing the third reflecting surface R3 of the image sensor 8. In other words, as shown in the drawing, the outer shape line A perpendicular to the optical axis OB of the reflecting member 101 is arranged so as to be on the reflecting surface R2 side by t from the outer surface B facing the third reflecting surface R3 of the image pickup device 8. Has been. By doing so, the end surface A2 of the reflecting member 101 can be arranged closer to the optical axis OD side (corresponding to t2 in the drawing) than the side end surface of the substrate KB, and the first lens group 1 (not shown) is configured. Even if the diameter of the lens is large, the width of the outer shape of the lens barrel 50 can be kept small.

  FIG. 3 is a movement diagram of each lens group during zooming. This figure schematically shows the movement of each lens group, the broken lines indicate the positions of the first to third reflecting surfaces R1, R2, and R3, and the numbers on the vertical axis indicate the lens groups, respectively.

  As shown in the figure, the first lens group 1, the third lens group 3, and the sixth lens group 6 are fixed lens groups, and the second lens group 2, the fourth lens group 4, and the fifth lens group 5 are wide-angle. Zooming is performed by moving between the end (W) and the telephoto end (T) as shown in the figure. The fifth lens group 5 is further moved from the position moved by zooming to perform focusing.

  FIG. 4 is a perspective view showing an appearance of an example of the lens barrel 50 according to the present embodiment.

  FIG. 5 is an exploded perspective view of the lens barrel 50 shown in FIG.

  In the following drawings, the same reference numerals are given to the same functional members as those described in FIGS.

  In the lens barrel 50 shown in FIGS. 4 and 5, a plate-like rotation member 28 that rotates in a plane parallel to a plane including the substantially parallel optical axis OB and the optical axis OD is disposed. . The rotating member 28 is formed with a cam groove 28m. A hole 28c, which is the rotation center of the rotation member 28, is incorporated in and fitted into a shaft portion 10p formed in the main body 10. The cam groove 28m is engaged with a pin 24p formed integrally with a lens frame 24k that integrally holds the second lens group 2 and the fourth lens group 4. A gear portion 28 g is formed on the outer periphery of the rotating member 28, and meshes with a pinion gear 27 that is rotated by the stepping motor 26.

  Thus, the rotation member 28 is rotated by the driving of the stepping motor 26, and the pin 24p, that is, the lens frame 24k engaged with the cam groove 28m is guided by the guide shafts 11 and 12 and moved in the optical axis direction. It is done.

  Note that the FPC is a flexible printed circuit board that is connected between an image sensor and another circuit for exchanging signals with another circuit.

  As shown in the drawing, the outer shape of the lens barrel 50 can be gathered into a substantially rectangular shape by arranging the motor as the driving portion on the slope portion formed by the third reflecting surface. Miniaturization is possible. Note that the same effect can be obtained even if a motor as a drive unit is disposed on the inclined surface formed by the second reflecting surface.

  FIG. 6 is a perspective view showing the appearance of another example of the lens barrel 50 according to the present embodiment.

  FIG. 7 is an exploded perspective view of the lens barrel 50 shown in FIG.

  The lens barrel 50 shown in FIGS. 6 and 7 rotates a plate-like rotation member 28 that moves the lens frame 24k about the optical axis OA of the lens group 1a constituting the first lens group 1 as a rotation center. It is arranged at the position to be moved.

  As shown in the figure, the rotating member 28 is rotatably supported by an annular portion 10r of the main body 10 that holds the lens group 1a disposed in front of the reflecting member 101 (subject side). The rotating member 28 is formed with a cam groove 28m. The cam groove 28m is engaged with a pin 24p formed integrally with a lens frame 24k that integrally holds the second lens group 2 and the fourth lens group 4. A gear portion 28 g is formed on the outer periphery of the rotating member 28, and meshes with a pinion gear 27 that is rotated by the stepping motor 26.

  Thus, the rotation member 28 is rotated by the driving of the stepping motor 26, and the pin 24p, that is, the lens frame 24k engaged with the cam groove 28m is guided by the guide shafts 11 and 12 and moved in the optical axis direction. It is done.

  Further, as in the present example, the reflecting members constituting the second reflecting surface R2 and the third reflecting surface R3 may not be integrated but may be separated into the reflecting member 102a and the reflecting member 102b, respectively.

  In the above-described embodiment, the zoom lens including six lens groups has been described as an example. However, the present invention is not limited to this, and the optical system has three reflecting surfaces and the first reflecting lens. The present invention is applicable as long as the optical axis after being reflected by the surface and the optical axis after being reflected by the third reflecting surface are arranged in parallel. In addition, the term “parallel” as used in the present specification includes not only parallel in a strict sense but also those having a slight deviation that causes no practical problem.

It is a figure which shows an example of the internal arrangement | positioning of the main structural unit of a camera which is an example of the imaging device provided with the lens barrel which concerns on this Embodiment. It is a schematic cross section which shows the schematic structure inside the lens barrel which concerns on this Embodiment. It is a movement diagram at the time of zooming of each lens group. It is a perspective view which shows the external appearance of an example of the lens barrel which concerns on this Embodiment. FIG. 5 is an exploded perspective view of the lens barrel shown in FIG. 4. It is a perspective view which shows the external appearance of the other example of the lens barrel which concerns on this Embodiment. FIG. 7 is an exploded perspective view of the lens barrel shown in FIG. 6.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st lens group 2 2nd lens group 3 3rd lens group 4 4th lens group 5 5th lens group 5k Lens frame 5s Female thread member 6 6th lens group 7 Optical filter 8 Imaging element 10 Main trunk 11, 12 Guide Shaft 15 ND filter (light quantity regulating member)
16 shutter 23 shutter case 24k lens frame 25, 26 stepping motor 25r lead screw 27 pinion gear 28 rotating member 31, 32 motor 50 lens barrel 100 camera 101, 102 reflecting member R1, R2, R3 reflecting surface OA, OB, OC , OD Optical axis FPC Flexible printed circuit board

Claims (7)

Between the plurality of lens groups and the lens groups, the first reflecting surface, the second reflecting surface, the third reflecting surface, and the rear of the third reflecting surface are arranged in order from the object side. And a lens barrel arranged so that an optical axis after being reflected by the first reflecting surface and an optical axis after being reflected by the third reflecting surface are parallel to each other ,
A lens barrel, wherein the reflecting member having the first reflecting surface is disposed closer to the second reflecting surface than the outer surface facing the third reflecting surface of the imaging element. One of the light amount regulating member and the shutter is disposed between the first reflecting surface and the second reflecting surface, and the light amount regulating member and the shutter are disposed between the third reflecting surface and the imaging surface of the imaging element. The lens barrel according to claim 1, wherein the other of the two is disposed. A plate formed with a cam groove that rotates in a plane parallel to a plane including the optical axis after being reflected by the first reflecting surface and the optical axis after being reflected by the third reflecting surface. The lens barrel according to claim 1, wherein the lens barrel is moved by rotating the rotating member. The cam groove of the rotating member is disposed between the lens group disposed between the first reflective surface and the second reflective surface, the third reflective surface, and the imaging surface of the imaging element. The lens barrel according to any one of claims 1 to 3, wherein the lens barrel is engaged with a pin formed on a lens frame that holds the lens group. The lens barrel according to any one of claims 1 to 4, wherein at least a moving lens group among the plurality of lens groups is supported by two guide shafts. The lens barrel according to any one of claims 1 to 5, wherein a drive unit is disposed on a slope portion formed by the second reflecting surface or the third reflecting surface. An imaging apparatus comprising the lens barrel according to claim 1.

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