JP2006301187A - Zoom-lens collapsible lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a zoom-lens collapsible lens barrel which can optically adjust an imaging device and is made thin in a collapsed state. <P>SOLUTION: The zoom-lens collapsible lens barrel 100 includes: a fourth group holder 120 that holds an optical LPF 103 and a fourth group lens 107; screws 122a, 122b and 122c screwed to a lens-barrel mounting base plate 102; nuts 123a, 123b and 123c that engage with the screws 122a, 122b and 122c respectively; and a CCD mounting plate 124 for holding a CCD 101. Compression springs 125a, 125b and 125c are inserted into areas between the CCD mounting plate 124 and the screws 122a, 122b and 122c such that the CCD mounting plate 124 is pressed against faces abutting on the nuts 123a, 123b and 123c. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a zoom lens retractable lens barrel, and more particularly to a zoom lens retractable lens barrel used in an imaging apparatus such as a digital camera.

  2. Description of the Related Art Conventionally, a retractable lens barrel is often used for an imaging apparatus such as a digital still camera. The collapsible lens barrel has a photographing state in which a plurality of photographing lenses are arranged at a desired lens interval, and a storage state (collapsed state) in which the lens interval and the distance from the imaging surface are narrower than those in the photographing state. Further, the retractable lens barrel is set so that the entire length of the lens barrel is changed by an extension mechanism such as a cam or a helicoid between the photographing state and the retracted state so that the lens barrel is appropriately arranged. Here, the retractable lens barrel can also be configured as a zoom lens retractable lens barrel that makes the focal length variable by configuring the lens groups to be driven separately.

  An imaging apparatus such as a digital still camera having a collapsible lens barrel having the above-described configuration is required to have portability and storability. reference).

  In addition, it is difficult to form the retractable lens barrel so that the lens and the lens holding means in the optical system have a desired eccentricity and inclination as designed. When the lens and the lens holding means in the optical system are deviated from the optical center, the image plane and the package surface of the image sensor are not perpendicular to the optical axis, that is, the image plane is tilted. In addition, when the imaging surface and the package surface of the imaging device are not parallel and are inclined, the optical system is inclined with respect to the optical axis when a lens is attached with reference to the package surface of the imaging device.

  Since the imaging surface and the package surface of the imaging device are not necessarily perpendicular to the optical axis, and the imaging surface and the package surface of the imaging device are not necessarily parallel, the imaging surface even if the center of the imaging surface is in focus The focus is shifted at a position other than the center of, for example, the focus is shifted in the opposite direction at two points across the center of the imaging surface. Therefore, in order to focus as much as possible in the entire area of the imaging surface, it is necessary to provide an imaging surface inclination correction mechanism that simultaneously corrects the tilt of the image surface and the inclination of the package surface of the imaging element.

  As shown in FIG. 6, the imaging surface inclination correction mechanism includes a CCD 1 as an imaging device having an imaging surface inside, a CCD holding plate 2 to which the CCD 1 is attached and fixed, and a hole formed in the CCD holding plate 2. 2a and a barrel base plate 3 having a pin-shaped protrusion 3b to be fitted. The hole 2a and the pin-shaped protrusion 3b are fitted with a minute backlash, and define the position of the imaging surface on the vertical plane with respect to the optical axis of the barrel base plate 3.

The imaging surface tilt correction mechanism further includes an optical low-pass filter (LPF) 4 that prevents the occurrence of luminance moiré and false colors having a repetitive pattern when photographing an object by the birefringence effect of quartz, and prevents the dust from entering the CCD surface. The rubber 5 to be cut off, the CCD mask sheet 6 for blocking light other than the imaging light beam, and the three holes 3c having the seating surface provided on the CCD side surface of the lens barrel base plate 3 are loosely fitted and separated in the optical axis direction. The CCD holding plate 2 is pressed against the barrel base plate 3 against the urging force of the compression spring 7 by being screwed into the barrel base plate 3 with a compression spring 7 that presses the CCD holding plate 2 and the barrel base plate 3 in the direction. Then, three adjustment screws 8a, 8b, and 8c for adjusting the inclination of the imaging surface by appropriately rotating so as to eliminate the inclination of the image surface of the CCD holding plate 2 are provided.
JP 2004-325555 A

  However, in the imaging surface inclination correction mechanism having the above-described configuration, the adjustment of the inclination of the imaging surface is performed by the adjusting screws 8a, 8b, and 8c, so that a space corresponding to an adjustment allowance for adjusting the inclination of the imaging surface is required. The tilt correction mechanism is enlarged in the optical axis direction.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a zoom lens retractable lens barrel that can optically adjust an image pickup device and can be thinned in a retracted state.

  In order to achieve the above object, a zoom lens retractable lens barrel according to claim 1 is provided with an image pickup device, a holding member that holds the image pickup device, and an optical adjustment member that optically adjusts the image pickup device. In the lens barrel, when the zoom lens retractable lens barrel is in the retracted state, a pressing member that presses the holding member so that the imaging element moves in the optical axis direction from a position optically adjusted by the optical adjusting member. It is characterized by providing.

  According to the present invention, when the zoom lens retracting lens barrel is in the retracted state, the pressing member presses the holding member, so that the image pickup element moves in the optical axis direction from the position optically adjusted by the optical adjusting member. In addition, the image sensor can be optically adjusted, and thinning in the retracted state can be realized.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view schematically showing a configuration of a zoom lens retractable lens barrel according to an embodiment of the present invention, and shows a case where the zoom lens retractable lens barrel is in a photographing state.

  In FIG. 1, a zoom lens retractable lens barrel 100 is fixed to a lens barrel mounting base plate 102 that holds each component constituting the zoom lens retractable lens barrel 100, and is screwed to the lens barrel mounting ground plate 102 so as to be coaxial with the optical axis. The cover barrel 108, the drive barrel 110 coaxially accommodated in the cover barrel 108 along the optical axis direction, the barrel mounting base plate 102 and the cover barrel 108 are fixed, and are coaxial with the drive barrel 110. And a fixed cylinder 111 accommodated along the optical axis direction, a movable cam cylinder 112 coaxially accommodated in the fixed cylinder 111 and slidably accommodated along the optical axis direction, and coaxial with the movable cam cylinder 112 Further, the linearly moving cylinder 113 is slidably accommodated along the optical axis direction, and the first group lens barrel 115 is accommodated coaxially and slidably along the optical axis direction.

  The drive cylinder 110 has a gear 110a provided on the outer peripheral surface, and rectilinear grooves 110b formed at three locations on the inner side so as to be parallel to the central axis and the optical axis direction.

  The fixed cylinder 111 has a feeding taper cam 111a having the same shape and is equally divided at three places, and a feeding cam formed as a through hole having the same shape and being equally divided at three places. 111 b and rectilinear grooves arranged equally at three locations inside the fixed cylinder 111.

  The moving cam cylinder 112 includes a follower pin 112a projecting as a cam follower, a drive pin 112b screwed and fixed to the moving cam cylinder groove 112c, and a rectilinear groove formed so as to be equally divided at three positions on the inner front side. 112e. The tapered portion at the tip of the follower pin 112a is in sliding contact with the feed-out taper cam 111a, and the drive pin 112b passes through the feed-out cam 111b and is fitted with the rectilinear groove 110b.

  The rectilinear cylinder 113 is provided with projections 113a that are equally disposed at three positions on the rear end, straight holes 113b that are disposed at three positions on the inner side and perpendicular to the optical axis, and that are equally disposed at three positions on the inner front. It has a feeding taper cam groove 113c and a feeding cam 113d formed in a shape.

  The first group lens barrel 115 includes a lens holding member 115a joined therein, a follower pin 115b protruding as a cam follower, and a drive pin 115c screwed and fixed to the first group lens barrel groove 115d.

  The zoom lens retractable lens barrel 100 is rotatably supported by the lens barrel mounting base plate 102 and the cover lens barrel 108, and is disposed inside the drive gear 109 that meshes with the gear 110a and the rectilinear tube 113, and includes a shutter unit, A second group lens barrel 114 on which the aperture unit is mounted, a guide rod 117 fixed to the lens barrel mounting base plate 102, an auxiliary guide rod 118, a motor 119, a screw 119a, a bearing member 119b, and a 3 attached to the guide rod 117 And a group barrel 116.

  The second group lens barrel 114 has follower pins 114a protruding at equal intervals at three positions on the outer side.

  Further, the zoom lens retractable lens barrel 100 includes a CCD 101 as an image sensor and an optical low-pass filter (LPF) 103 (adjacent member) that prevents the occurrence of luminance moire and false colors having a repetitive pattern when photographing a subject by the birefringence effect of quartz. ), A first group lens 104 composed of a compensator lens, a second group lens 105 composed of a variator lens, a third group lens 106 composed of a focusing lens, and a fourth group lens 107 composed of a relay lens. Here, the first lens group 104, the second lens group 105, the third lens group 106, and the fourth lens group 107 constitute an optical system of a zoom lens collapsible lens barrel 100 that is a two-stage collapsing lens having a four-group configuration. .

  In the zoom lens retractable lens barrel 100 having the above-described configuration, when the rotational force of a motor (not shown) is transmitted by the drive gear 109 and the drive cylinder 110 is driven to rotate, the movable cam cylinder 112 is fixed to the fixed cylinder via the follower pin 112a. The drive pin 112b moves in the optical axis direction while being restricted in rotation by the rectilinear groove 110b by receiving a force in the rotation direction along the 111 feeding taper cam 111a.

  Further, the projecting portion 113a is fitted to the movable cam cylindrical groove 112c and is prevented from coming off, and is restricted from rotating along the straight advance grooves arranged equally at three locations inside the fixed cylinder 111. Reference numeral 113 follows the movement of the movable cam cylinder 112 in the optical axis direction and interlocks.

  Further, the taper portion at the tip of the follower pin 115b is slidably contacted with the feeding taper cam groove 113c, and the driving pin 115c passes through the feeding cam 113d and engages with the rectilinear groove 112e. As the tube 112 rotates, the tube 112 moves in the optical axis direction while rotating along the tapered cam groove 113c.

  As described above, when the rectilinear cylinder 113 and the first group lens barrel 115 move in the optical axis direction, the zoom lens retractable lens barrel 100 shifts from the photographing state to the retracted state (FIG. 2).

  Further, the follower pin 114a passes through the rectilinear hole 113b and the tapered portion of the tip is slidably contacted with the tapered cam groove 112d, so that the second group barrel 114 moves in the optical axis direction while the movable cam barrel 112 rotates. In conjunction with this, it moves only in the direction orthogonal to the optical axis along the shape of the tapered cam groove 112d.

  The zoom lens retractable lens barrel 100 according to the present embodiment includes a guide rod 117 and an auxiliary guide rod 118 that support the third group lens barrel 116, a screw 119a that is rotated by a motor 119, and a bearing member 119b that supports the screw 119a. By the above operation, the third group lens barrel 116 is focused by moving along the optical axis direction. That is, the third group barrel 116 is supported so that the nut screwed with the screw 119a does not rotate, and the third group barrel 116 is driven in the optical axis direction by the motor 119, so that a focusing operation is possible. Become.

  FIG. 3 is an exploded perspective view schematically showing a configuration of a main part of the zoom lens retractable lens barrel of FIG.

  In FIG. 3, the zoom lens retractable lens barrel 100 has a bellows shape that prevents dust from entering between the optical LPF 103 and the fourth group holder 120 (pressing member) that holds the fourth group lens 107 and the CCD 101 and the optical LPF 103. A screw screw 122a, 122b, 122c (locking member) having a dust-proof rubber 121, a threaded portion with a fixed pitch screwed to the lens barrel mounting base plate 102, and a screw head provided on an end surface opposite to the threaded portion; Nuts 123a, 123b, and 123c (locking members) that are screwed into the screw screws 122a, 122b, and 122c, and a CCD mounting plate 124 (holding member) that holds the CCD 101 are provided. The CCD mounting plate 124 includes holes 124a, 124b, and 124c through which the screw screws 122a, 122b, and 122c pass, and holes 124d and elongated holes that fit into pin-shaped protrusions 102a and 102b that stand on the lens barrel mounting base plate 102. 124e, and the positions in the direction parallel to the lens barrel mounting base plate 102 are determined by these holes 124a to 124e. Compression springs 125a, 125b, 125c (attached) between the CCD mounting plate 124 and the screw heads of the screw screws 122a, 122b, 122c so as to press the CCD mounting plate 124 against the contact surfaces with the nuts 123a, 123b, 123c. Force member) is inserted.

  With the configuration of the zoom lens retractable lens barrel 100 in FIG. 3, when the outer peripheral portions of the nuts 123 a, 123 b, and 123 c rotate, the position of the CCD mounting plate 124 in the optical axis direction changes. Can be adjusted.

  FIG. 4 is a schematic cross-sectional view schematically showing a configuration of a main part of the zoom lens retractable lens barrel in FIG. 1, and shows a case where the zoom lens retractable lens barrel is in a photographing state.

  In FIG. 4, when the zoom lens retractable lens barrel 100 is in the photographing state, the third group lens barrel 116 is extended to the subject side in the optical axis direction up to the photographing driving range. The fourth group holder 120 is abutted to a desired optical design position along the guide formed on the lens barrel mounting base plate 102 by the elastic force of the dust-proof rubber 121. The CCD mounting plate 124 is subjected to optical adjustment on the subject side in the optical axis direction along the protrusions 102a and 102b by the spring restoring force (biasing force) of the compression springs 125a, 125b, and 125c, that is, nuts 123a and 123b. , 123c to the position of the contact surface. In this manner, since the CCD 101 is again abutted to the position where the tilt of the CCD 101 is optically adjusted first, it is possible to take a picture again while correcting the tilt of the image plane.

  FIG. 5 is a schematic cross-sectional view schematically showing a configuration of a main part of the zoom lens retractable lens barrel of FIG. 1, and shows a case where the zoom lens retractable lens barrel is in a retracted state.

  In FIG. 5, when the zoom lens retractable lens barrel 100 is in the retracted state, if the third lens barrel 116 is driven back to the CCD 101 beyond the photographing driving range, the third lens group 106 and the fourth lens group 107 are moved. The third lens group 106 is brought into contact with the fourth lens group holder 120 and further pushed into the CCD 101 side.

  In the state where the gap between the CCD 101 and the optical LPF 103 is minimized, the fourth group holder 120 presses the CCD mounting plate 124 to minimize the gap between the zoom lens collapsible lens barrel 100 and the members existing on the rear surface. Push to the point. At this time, the CCD mounting plate 124 that has been in contact with the nuts 123a, 123b, and 123c by the compression springs 125a, 125b, and 125c is separated from the contact surface with the nuts 123a, 123b, and 123c. In this state, all members arranged on the optical axis are set to have a minimum gap.

  According to the present embodiment, in the retracted state, the fourth group holder 120 presses the CCD mounting plate 124, and the CCD 101 is a nut so that all the members arranged on the optical axis have a minimum gap. While moving in the optical axis direction from the contact surfaces with 123a, 123b, and 123c and changing from the tilt-adjusted posture, the CCD 101 moves to the contact surfaces with the nuts 123a, 123b, and 123c in the photographing state. At the same time, since the posture is adjusted, the image pickup device can be optically adjusted and thinned in the retracted state.

  In the present embodiment, the urging force of the compression springs 125a, 125b, and 125c is used to move the CCD 101 and the CCD mounting plate 124 in the optical axis direction. However, the present invention is not limited to this. Controllable drive means such as a stepping motor is provided for a plurality of axes for optical adjustment, and the positions of the CCD 101 and the CCD mounting plate 124 in the optical axis direction are driven and controlled for each of the shafts, whereby the CCD 101 and the CCD are mounted. With the inclination of the plate 124 corrected, the CCD 101 and the CCD mounting plate 124 are held at the optically adjusted position in the photographing state and in the retracted state so that all members disposed on the optical axis have a minimum gap. May be moved.

1 is a schematic cross-sectional view schematically showing a configuration of a zoom lens retractable lens barrel according to an embodiment of the present invention, and shows a case where the zoom lens retractable lens barrel is in a photographing state. 1 is a schematic cross-sectional view schematically showing a configuration of a zoom lens retractable lens barrel according to an embodiment of the present invention, and shows a case where the zoom lens retractable lens barrel is in a retracted state. FIG. 2 is an exploded perspective view schematically showing a configuration of a main part of the zoom lens retractable lens barrel of FIG. 1. FIG. 2 is a schematic cross-sectional view schematically showing a configuration of a main part of the zoom lens retractable lens barrel of FIG. 1, showing a case where the zoom lens retractable lens barrel is in a photographing state. FIG. 2 is a schematic cross-sectional view schematically showing a configuration of a main part of the zoom lens retractable lens barrel of FIG. 1, showing a case where the zoom lens retractable lens barrel is in a retracted state. It is a disassembled perspective view which shows schematically the structure of the conventional imaging surface inclination correction mechanism.

Explanation of symbols

100 Zoom lens retractable lens barrel 101 CCD
103 Optical LPF
107 4th lens group 120 4th lens group holder 122a Screw screw 122b Screw screw 122c Screw screw 123a Nut 123b Nut 123c Nut 124 CCD mounting plate 125a Compression spring 125b Compression spring 125c Compression spring

Claims (4)

  A zoom lens collapsible lens barrel comprising an image sensor, a holding member that holds the image sensor, and an optical adjustment member that optically adjusts the image sensor, and the imaging when the zoom lens retractable lens barrel is in a retracted state A zoom lens retractable lens barrel comprising a pressing member that presses the holding member so that the element moves in the optical axis direction from a position optically adjusted by the optical adjusting member.   An adjacent member adjacent to the image sensor in the optical axis direction is provided, and the distance between the image sensor and the adjacent member when the zoom lens retractable lens barrel is in a retracted state is such that the zoom lens retractable lens barrel is in a shooting state. The zoom lens retractable lens barrel according to claim 1, wherein the zoom lens retractable lens barrel is smaller than a distance between the imaging element and the adjacent member.   A driving unit that moves the image sensor in an optical axis direction; and a control unit that controls the driving unit. When the zoom lens retractable lens barrel is in a shooting state, the control unit moves the image sensor into the optical unit. 3. The zoom lens retractable lens barrel according to claim 1, wherein the driving unit is controlled so as to be held at a position optically adjusted by an adjusting member.   The optical adjustment member includes a plurality of locking members that adjust the position of the image sensor in the optical axis direction, and a biasing member that biases the holding member so as to press the locking member. The zoom lens collapsible lens barrel moves from the retracted state to the photographing state, and the image pickup element moves to a position optically adjusted by the locking member by the urging force of the urging member. 4. The zoom lens retractable lens barrel according to claim 1.

Images