JP4224051B2 - Lens barrel and photographing device - Google Patents

Description

  The present invention accommodates a photographic lens composed of a plurality of lens groups including at least a variable magnification lens group and a focus adjustment lens group, and is capable of being extended and retracted freely. When the lens is extended, the photographic lens performs focal length adjustment and focus adjustment. The present invention relates to a lens barrel and an imaging apparatus that includes such a lens barrel and performs imaging by capturing subject light that has passed through the lens barrel.

  In recent years, in addition to conventional cameras that take photographs on silver halide films, a solid-state image sensor such as a CCD image sensor or a CMOS image sensor is provided, and a subject image is formed on the solid-state image sensor to generate an image signal. This type of digital camera is rapidly spreading.

  Also in this digital camera, improvement in portability as well as improvement in shooting performance is strongly demanded. Among these digital cameras, a lens barrel containing a shooting lens composed of a plurality of lens groups is provided to make the focal length variable. As a result, it is possible to shoot at a desired angle of view, and for convenience of carrying, the distance between a plurality of lens groups constituting the photographic lens should be less than the minimum required for shooting when not shooting. There is a type that is retracted into the camera housing and is extended from the camera housing so that the distance between the plurality of lens groups becomes a distance required for photographing at the time of photographing (see Patent Document 1).

Also, digital cameras that reduce the distance between built-in lens groups to less than the minimum distance required for shooting when retracted are so-called black that prevents non-imaged images from being displayed on the LCD panel on the back of the camera. A measure called “out” is taken when retracting.
Japanese Patent Laid-Open No. 5-34769

  This means that a digital camera equipped with a lens barrel as described above cannot shoot subject light on a solid-state image sensor when retracted, apart from not implementing blackout measures. For example, even when you carry a digital camera and need to take a picture of a bag, the lens barrel is installed from the retracted position to the built-in lens group. It is necessary to wait for the distance between them to be extended to a predetermined extension position that secures a minimum distance required for photographing, and there is a possibility of missing a photo opportunity.

  This also applies to a so-called silver salt camera that takes a picture on a roll film or the like.

  In view of the above circumstances, an object of the present invention is to provide a camera whose thickness is reduced by retracting a lens barrel.

The lens barrel of the present invention that achieves the above object includes a first group, a second group, a third group, and a fourth group in order from the front in the optical axis direction, including at least a variable magnification lens group and a focusing lens group. In a lens barrel that houses a photographic lens and can change the tube length between a relatively short tube length storage state and a relatively long tube length shooting state,
Along with the transition to the retracted state, at least the retracting lens group that is one of the third group and the fourth group of the plurality of lens groups is retracted from the photographing optical axis, and the transition to the photographing state is performed. Along with this, a lens advancing / retreating mechanism for advancing the retracting lens group on the photographing optical axis,
The lens advance / retreat mechanism is:
A spring member for rotating the retractable lens group in a predetermined first rotation direction;
And a cam mechanism that rotates in a second rotation direction opposite to the first rotation direction against a biasing force of the spring member in accordance with a change in the tube length. .

  Here, in the lens barrel according to the present invention, the cam mechanism rotates in contact with the first member having a slope facing the oblique direction with respect to the photographing optical axis and the slope according to the change of the tube length. By doing so, it is preferable to include a second member that rotates the retractable lens group in the second rotation direction.

  In the lens barrel of the present invention, the first group, the second group, the third group, and the fourth group have a positive refractive power, a negative refractive power, a positive refractive power, and a positive refractive power, respectively. A lens group having power is preferable.

  Furthermore, in the lens barrel of the present invention, the photographic lens may form a photographic optical system with the remaining lens groups excluding the retractable lens group retracted from the photographic optical axis when in the retracted state. Good.

  In this case, the photographing lens may form a fixed focus photographing optical system by the remaining lens group when in the retracted state.

The imaging device of the present invention that achieves the above object is an imaging device that performs imaging by capturing subject light,
An imaging lens composed of a first group, a second group, a third group, and a fourth group in order from the front in the optical axis direction, including at least a variable magnification lens group and a focus adjustment lens group;
A lens barrel that houses the photographic lens, and that can be extended and retracted, and that allows the photographic lens to perform focal length adjustment and focus adjustment when extended;
The lens barrel retracts the retracting lens group including at least one of the third group and the fourth group from the photographing optical axis in accordance with the transition to the retracted state. A lens advancing / retreating mechanism that advances the retractable lens group on the photographing optical axis in accordance with the transition to the photographing state,
The lens advancing / retracting mechanism includes a spring member that rotates the retractable lens group in a predetermined first rotation direction, and the first rotation against the urging force of the spring member as the tube length changes. And a cam mechanism for rotating in a second rotation direction opposite to the direction.

  Here, in the photographing apparatus according to the present invention, the cam mechanism rotates in contact with the first member having a slope inclined in an oblique direction with respect to the photographing optical axis and the slope according to the change of the tube length. Accordingly, it is preferable to include a second member that rotates the retractable lens group in the second rotation direction.

  In the lens barrel of the present invention, the first group, the second group, the third group, and the fourth group have a positive refractive power, a negative refractive power, a positive refractive power, and a positive refractive power, respectively. It may be a lens group having power.

  Furthermore, in the lens barrel of the present invention, the photographic lens may form a photographic optical system with the remaining lens groups excluding the retractable lens group retracted from the photographic optical axis when in the retracted state. Good.

  In this case, the photographing lens may form a fixed focus photographing optical system by the remaining lens group when in the retracted state.

  In the present invention, when retracted, at least one lens group among a plurality of lens groups positioned on the photographing optical axis when retracted is retracted from the photographing optical axis, so that the photographing lens can be reduced in thickness by being retracted.

  Hereinafter, embodiments of the present invention will be described.

  FIG. 1 is an external view of a digital camera according to a first embodiment of the present invention.

  FIG. 1A shows the retracted state of the lens barrel 100 incorporating the zoom lens of the digital camera 1 of the present embodiment, and FIG. 1B shows the lens mirror of the digital camera 1. The state where the cylinder 100 is extended is shown. FIG. 1C shows the back of the digital camera 1.

  The lens barrel 100 of the digital camera 1 shown in FIG. 1 incorporates a photographing lens composed of three groups as will be described later, and the focal length can be adjusted by moving these lens groups in the optical axis direction. At the same time, focus adjustment is performed by moving the third group focus lens in the optical axis direction. The lens barrel 100 is a lens barrel that can be freely changed between a storage state with a relatively short tube length and a shooting state with a relatively long tube length.

  An auxiliary light emission window 12 and a viewfinder objective window 13a are arranged at the upper front of the digital camera 1 shown in FIG. A shutter button 14 is disposed on the upper surface of the digital camera 1. The shutter button 14 has two stages of half-press and full-press, and the above-described focus adjustment is performed by half-press, and photographing is performed by full-press. A lens barrier 100a is provided on the front surface of the lens barrel 100 to cover the front surface of the lens barrel when retracted.

  On the back of the digital camera 1, a power switch 15, a viewfinder eyepiece window 13b, an image monitor 20, a setting display button 16, a recording instruction button 17, an image display on / off button 20a, a cross key 19, and a zoom operation switching button 18 are provided. When the zoom operation mode is entered by continuing to press the zoom operation switch button 18 for a predetermined time, the lens barrel 100 moves to the telephoto side while the mark indicating “up” of the cross key 19 is kept pressed. The lens barrel 100 moves to the wide-angle side while the mark indicating “below” of the cross key 19 is kept pressed. The release of the zoom operation mode is performed again by continuously pressing the zoom operation switching button 18 for a predetermined time.

  The image display on / off button 20a is a button for instructing whether or not to display an image on the image monitor 20. In the digital camera 1, even if the image display on / off button 20a is turned off, the image display on / off button 20a is obtained by photographing. The image is displayed on the image monitor 20 for a predetermined time. Note that shooting when the image monitor 20 is off is performed by checking the object scene from the viewfinder 13.

  The setting display button 16 is a button operated when displaying values such as the currently set shutter speed and sensitivity. The recording instruction button 17 is a button operated when recording a captured image in a memory.

  The viewfinder eyepiece window 13b forms an optical viewfinder between the front viewfinder objective window 13a.

  The power switch 15 is a switch operated to activate the digital camera 1. In the digital camera 1, a position “reproduction” for designating a reproduction mode that is a mode for displaying an image recorded in a memory or the like on the image monitor 20, and a position “ A position “normal” for designating normal photography including “collapse” and movie mode is provided, and the power switch 15 is slidable including a position “OFF” for turning off the power. FIG. 1C shows a state in which the power switch 15 is set to the position “collapse”.

  In this digital camera 1, the lens barrier 100 a is closed using the force by which the power switch 15 is slid from the position “collapse” to the position “OFF”, and the force is slid from the position “OFF” to the position “collapse”. The lens barrier 100a is opened by use. Therefore, when the power switch 15 is slid from the position “OFF” to the position “normal”, the lens barrier 100a is opened when passing the intermediate position “collapse”.

  FIG. 2 is a view showing the arrangement of the lens groups on the photographing optical axis when the photographing lens of the digital camera of this embodiment is extended and retracted.

  FIG. 2A shows the arrangement of the first to third lens groups on the wide-angle side when “normal” is selected by the power switch 15, and FIG. The arrangement of the first to third lens groups on the telephoto side when “normal” is selected by the power switch 15 is shown. FIG. 2C shows the arrangement of each lens group when the lens barrel is retracted when “collapse” is selected by the power switch 15. The retracted second lens group (a rear group lens described later) is not shown, and a first (a front group lens described later) and a third (a focus lens described later) are shown. In the digital camera 1 of the present embodiment, shooting is possible even when “collapse” is selected in addition to the case where “normal” is selected by the power switch 15. Shooting (hereinafter referred to as shooting when retracted) is fixed-focus shooting with the first lens group and the third lens group remaining on the shooting optical axis when the lens barrel is retracted. In FIG. 2, a CCD is also shown on the photographing optical axis.

  FIG. 3 is a schematic diagram showing the main components of the digital camera according to the first embodiment of the present invention when the lens barrel in the extended state is viewed from the optical axis direction. 4 is a cross-sectional view taken along line AA 'on the same cross-sectional view as FIG. 3, and FIG. 5 is a cross-sectional view taken along line DD' on the same cross-sectional view as FIG. FIG. 6 and FIG. 6 are diagrams showing a fault line GG ′ on the same sectional view as FIG. 7 is a cross-sectional view showing the telephoto end state having the longest focal length along the cross-sectional line AA ′ of FIG. 4, and FIG. 8 shows the cross-sectional line FF ′ on the same cross-sectional view as FIG. 9 is a cross-sectional view showing the state of the wide end with the shortest focal length along the cross-sectional line AA ′ in FIG. 4, and FIG. 10 is a cross-sectional view along the cross-sectional line GG ′ in FIG. FIG. 11 is a cross-sectional view showing main components in the wide end state along the tomographic line DD ′ of FIG. FIG. 12 is a schematic diagram showing main components of the lens barrel in the retracted state of the digital camera 1 according to the first embodiment shown in FIGS. 1 to 11 when viewed from the optical axis direction. FIG. 13 is a cross-sectional view taken along line 15 to line EE ′, FIG. 13 is a view showing the line BB ′ and line CC ′ on the same cross-sectional view as FIG. 12, and FIG. FIG. 15 is a cross-sectional view taken along the line CC ′, FIG. 15 is a view showing the cross-sectional line EE ′ on the same cross-sectional view as FIG. 14, and FIG. It is sectional drawing which follows.

  In the following, description will be made mainly with reference to FIG. 7 and with reference to other drawings as necessary.

  The lens barrel 100 shown in FIGS. 3 to 16 accommodates a photographing lens 110 including three groups of a front lens group 111, a rear lens group 112, and a focus lens 113 in order from the front in the optical axis direction. ing. In this photographic lens 110, the focal length changes when the rear group lens 112 moves between the tele end shown in FIG. 7 and the wide end shown in FIG. 9, and the focus lens 113 moves in the optical axis direction. Thus, the focus adjustment is performed.

  An opening 102 through which the photographic lens 110 is viewed is formed at the front end of the internal space, and a wall member 103 fixed to the camera body or constituting a part of the camera body is disposed behind the internal space. The contour of the wall 101 is defined by the wall member 103 and a plurality of cylinders described later.

  Also, the front group lens 111 is held inside the front group frame 180 that has the smallest outer diameter among the plurality of cylinders and is arranged at the foremost position on the photographing optical axis when extended. Since the outer diameter of the front group lens 111 is smaller than the inner diameter of the front group frame 180, a space is formed between the front group lens 111 and the front group frame 180 on the side of the front group lens 111. Yes. Here, in the following description, the space between the front group lens 111 and the front group frame 180 is referred to as the front group lens side 106.

  A CCD solid-state image sensor (hereinafter abbreviated as CCD) 120 is attached to the wall member 103 so as to protrude into the internal space 101. By disposing the CCD 120 at a position protruding into the internal space 101, a recessed portion 104 defined by the CCD 120 and the wall member 103 is formed on the side of the CCD 120.

  Further, a feed screw 131 (see FIG. 11) is rotatably supported on the wall member 103, and a nut member 132 shown in FIG. 11 is screwed onto the feed screw 131, and the nut member 132 is engaged with the nut member 132. The focus lens guide frame 133 that guides the focus lens 113 in the optical axis direction is fixed. The focus lens guide frame 133 is fixed to the nut member 132, and a guide bar 205 protruding from the wall member 103 is inserted into a fork-shaped groove 133a (see FIG. 3) provided in the focus lens guide frame 133. It is inserted. Therefore, the focus lens guide frame 133 moves in the optical axis direction by the rotation of the feed screw 131.

  A focus lens holding frame 134 that holds the focus lens 113 is fixed to the focus lens guide frame 133.

  The feed screw 131 into which the nut member 132 to which the focus lens guide frame 133 is fixed is screwed is rotationally driven by a focus motor (not shown) provided on the camera body side, and is fixed to the nut member 132 by the rotation of the feed screw 131. The focus lens guide frame 133 and the focus lens holding frame 134 fixed to the focus lens guide frame 133 are moved in the optical axis direction, whereby the focus lens 113 held by the focus lens holding frame 134 is moved to the optical axis. The focus lens 113 is adjusted so that a focused subject image is projected on the front surface of the CCD 120.

  A fixed cylinder 140 is fixed to the wall member 103, and a rotating cylinder 150 is provided inside the fixed cylinder 140. The rotary cylinder 150 is provided with a gear 151 meshed with a columnar gear 105 (see FIG. 3) on the outer periphery thereof, and the columnar gear 105 is rotationally driven by a lens barrel drive motor (not shown). The rotating cylinder 150 rotates. A cam groove 141 is formed on the inner wall of the fixed cylinder 140, and a cam pin 152 fixed to the rotary cylinder 150 is fitted into the cam groove 141. When a rotational driving force is received through the optical axis, it moves forward or backward in the optical axis direction while rotating.

  In addition, a rotary cylinder side linear key ring 154 is provided inside the rotary cylinder 150 so as to be rotatable with respect to the rotary cylinder 150, but not relatively movable in the optical axis direction with respect to the rotary cylinder 150. Further, a key plate 155 is fixed to the rotary cylinder side rectilinear key ring 154, and the key plate 155 is fitted into a key groove 142 formed on the inner wall of the fixed cylinder 140 and extending in the optical axis direction. The rotary cylinder side linear key ring 154 is prevented from freely rotating in the optical axis direction by the fixed cylinder 140. Therefore, when the rotary cylinder 150 moves in the optical axis direction while rotating, the rotary cylinder-side linear key ring 154 is not rotated because it is prevented from rotating with respect to the fixed cylinder 140, but in the optical axis direction, the rotary cylinder 150 is not rotated. Move with.

  A rotatable intermediate cylinder 160 is provided inside the rotary cylinder 150. A cam groove 156 is formed on the inner wall of the rotary cylinder 150, and a cam groove 157 is formed in the rotary cylinder side linear key ring 154 so as to penetrate the outer periphery and the inner periphery thereof. In the groove 156, a cam pin 161 provided in the intermediate cylinder 160 is inserted through the cam groove 157 of the rotary cylinder-side linear advance key ring 154. Therefore, when the rotary cylinder 150 rotates and moves in the optical axis direction, the intermediate cylinder 160 also rotates in accordance with the shape of the cam groove of the rotary cylinder 160 and the rotary cylinder side linear key ring 154, and further relative to the rotary cylinder 150. Move in the direction of the optical axis.

  An intermediate cylinder side straight key ring 164 is provided inside the intermediate cylinder 160. A straight key groove 158 is formed in the fixed cylinder side rectilinear key ring 154 described above, and the intermediate cylinder side rectilinear key ring 164 is fitted in the rectilinear key groove 158 of the fixed cylinder side rectilinear key ring 154. The intermediate cylinder side rectilinear key ring 164 is relatively rotatable with respect to the intermediate cylinder 160, while relative movement in the optical axis direction with respect to the intermediate cylinder 160 is prohibited. Therefore, when the intermediate cylinder 160 rotates and moves relative to the rotating cylinder 150 in the optical axis direction, the intermediate cylinder side rectilinear key ring 164 does not rotate, but the intermediate cylinder 160 moves in the optical axis direction. Moves straight in the direction of the optical axis.

  A cam groove 165 for guiding the rear group guide frame 170 is formed on the inner wall of the intermediate cylinder 160, and a cam pin 171 fixed to the rear group guide frame 170 is provided in the cam groove 165. The cylinder side straight key ring 164 is inserted in a state of being prevented from rotating. Therefore, when the intermediate tube 160 rotates, the rear lens group guide frame 170 moves straight in the optical axis direction according to the shape of the cam groove 165 on the inner wall of the intermediate tube 160.

  A rear group lens holding frame 172 that holds the lens shutter unit 179 and the rear group lens 112 is pivotally supported by the rear group lens guide frame 170 with respect to the rear group lens guide frame 170 by a rotation shaft 173. ing. When “OFF” is selected by the power switch 15, the rear group lens holding frame 172 is retracted into the recessed portion 104 beside the CCD 120 together with the rear group lens 112 and the lens shutter unit 179 as shown in FIG. When “NORMAL” is selected by the switch 15, as shown in FIG. 7 and the like, the camera advances along with the rear lens group 112 and the like on the photographing optical axis. The lens shutter unit 179 positioned in front of the rear lens group 112 includes an aperture member that controls the amount of subject light that passes through the photographing lens 110, and subject light that passes through the photographing lens 110 by controlling the shutter speed. Both are provided with a shutter member that controls the amount of light, and these are of the type that controls the amount of light using a PLZT element. The rotation range of the rear group lens holding frame 172 is such that the rear group lens 112 held by the rear group lens holding frame 172 moves to the use position (see FIGS. 7 and 9) where the rear group lens 112 has advanced on the photographing optical axis of the photographing lens 110. This is a range of turning between the retracted position (see FIG. 14) and entering the recessed portion 104 beside the CCD 120. In addition, a coil spring 174 is provided around the rotation shaft 173, and the rear group lens holding frame 172 is provided with a spring in a direction in which the rear group lens 112 rotates on the photographing optical axis of the photographing lens 110 by the coil spring 174. And is also urged in the direction of the optical axis.

  A mechanism for revolving the rear group lens holding frame 172 to retract the rear group lens 112 to the retracted position set in the recessed portion 104 will be described later.

  The intermediate tube 160 is formed with another cam groove 166 for guiding the front group frame 180 holding the front group lens 111, and the cam pin 181 provided in the front group frame 180 is formed in the cam groove 166. Has entered. Further, the front group frame 180 is stopped by the intermediate cylinder side rectilinear key ring 164 so as to freely move in the optical axis direction. Therefore, when the intermediate cylinder 160 rotates, the front group frame 180 moves straight in the optical axis direction with respect to the intermediate cylinder 160 according to the shape of the cam groove 166.

  With such a mechanism, when “OFF” is selected by the power switch 15 when the telephoto end is at the telephoto end in FIG. 7, the rotational driving force in the retracted direction is transmitted to the rotary cylinder 150 via the columnar gear 105. 7 is retracted from the tele end state to the state of FIGS. 14 and 16 through the wide end state of FIG. 9, and conversely, the power switch 15 is in the retracted state shown in FIGS. When “normal” is selected by the above and the rotational driving force in the feeding direction is transmitted to the rotating cylinder 150, the retracted state shown in FIGS. 14 and 16 is extended to the wide end state shown in FIG. The tele end state shown in FIG.

  When photographing is performed with “normal” selected by the power switch 15, the zoom operation switch described above is operated to adjust the focal length between the tele end shown in FIG. 7 and the wide end shown in FIG. Thus, the desired shooting angle of view is set. The focus lens 113 is focused to a position where the highest contrast can be obtained by contrast detection based on the image signal obtained by the CCD 120. Thereafter, when the shutter button is pressed, an image signal representing the subject at that time is generated by the CCD 120, subjected to appropriate image processing, and recorded.

  Here, a mechanism for turning the rear lens group 112 to the retracted position set in the recessed portion 104 will be described.

  As described above, the rear group lens holding frame 172 that holds the rear group lens 112 is rotatably supported by the rear group lens guide frame 170 by the rotation shaft 173, and the rear group lens by the coil spring 174 (see FIG. 3). A spring 112 is biased in a direction positioned on the photographing optical axis of the photographing lens 110. A lever member 175 shown in FIGS. 3 and 10 and the like is also rotatably supported on the rear lens group guide frame 170 by a rotation shaft 176. As shown in FIG. 3, the rear lens group holding frame 172 is provided with a fork-like engagement groove 178, and an engagement pin 177 provided at one end of the lever member 175 is provided in the engagement groove 178. It has entered.

  Here, on the wall member 103 that defines the rear surface of the internal space 101 of the lens barrel 100, as shown in FIG. 10, an end 175a opposite to the direction in which the engaging pin 177 of the lever member 175 is provided. A convex portion 209 having a shape protruding into the internal space 101 is formed in the movement direction of the retracted direction, and a tapered surface 209a is provided on the tip side of the convex portion 209. Therefore, when the rotary cylinder 150 rotates in the retracted direction, the intermediate cylinder 160 and the rear group guide frame 170 cam-engaged with the intermediate cylinder 160 also move in the retracted direction, and the end 175a of the lever member 175 is the taper of the convex portion 209. It strikes the surface 209a and moves along the tapered surface 209a, whereby the lever member 175 rotates from the rotational position shown in FIG. 3 to the rotational position shown in FIG.

  Then, since the engaging pin 177 of the lever member 175 enters the fork-shaped engaging groove 178 of the rear group holding frame 172, the rear group holding frame 172 also rotates around the rotation shaft 173, and the rear group The lens 112 is retracted from the position on the photographing optical axis shown in FIG. 3 to the retracted position shown in FIG. As shown in FIG. 14, the retracted position is a recessed portion 104 formed on the side of the CCD 120.

  When the retracted state shown in FIGS. 14 and 16 is moved in the feeding direction, the protrusion 209 protruding from the wall member 103 and the lever member 175 shown in FIG. 10 are disengaged from each other, and the rear group holding frame 175 is a coil spring. 12 is rotated from the state shown in FIG. 12 to the state shown in FIG. 3, whereby the rear lens group 112 is rotated from the retracted position shown in FIG. 14 to a position on the photographing optical axis.

  In the digital camera 1 of the first embodiment, as described above, the rear group lens 112 is retracted while being disposed on the photographing optical axis without having a mechanism for retracting the lens group on the photographing optical axis from the photographing optical axis. In a digital camera equipped with a conventional retracting and feeding mechanism, it is reduced in thickness by being retracted to a recessed portion 104 on the side of the CCD 120, which is likely to become a dead space, and a positive image remaining on the photographing optical axis. A fixed-focus imaging optical system is formed by the front lens group 111 having a refractive power of 5 and a focus lens having the same positive refractive power. This fixed focus photographing optical system is adapted to focus at a distance of 1 to 2 m from the camera, and can be photographed when retracted when “collapse” is selected by the power switch 15. Hereinafter, in the description of FIG. 17, the details of the retracted photographing will also be described.

  FIG. 17 is a block diagram showing a circuit configuration of the digital camera shown in FIGS.

  The digital camera 1 includes the photographing lens 110, the barrier 100a for protecting the photographing lens 110, the lens shutter unit 179, and the CCD 120 described above. In the digital camera 1, when the position “normal” is selected by the power switch 15, the lens barrel 100 is extended with the barrier 100 a opened until the angle of view reaches a predetermined wide angle side. On the other hand, when the power switch 15 is set to the “collapsed” position and photographing at the time of collapsing is selected, the lens barrel 100 is not extended but only the barrier 100a is opened, and the front group lens and the focus lens Thus, it is possible to shoot with a fixed focus formed by. Note that the case where “normal” is selected by the power switch 15 means a photographing state, which is a state where an image is formed using all of a plurality of lens groups constituting the photographing lens 110, and here, when retracted Shooting means the storage state, and the tube length is shortened beyond the shortest tube length state in the shooting state.

  That is, when the photographic lens shifts to the retracted position further retracted from the widest position (when the photographic lens shifts to the retracted state), the second lens group retracts from the optical axis, and the retracted position (accommodated state). It becomes possible to shoot with.

  For example, a photographic lens which is composed of a plurality of lens groups and has a variable focal length and adjusts the focus is accommodated, and a tube length between a relatively short tube length storage state and a relatively long tube length shooting state is accommodated. In a lens barrel that can be changed freely, a lens retracting mechanism that retracts at least one of the plurality of lens groups from the photographing optical axis in accordance with the transition to the retracted state, and a transition to the photographing state A lens advancing mechanism that advances the retracted lens group onto the photographic optical axis, and the photographic lens is retracted from the photographic optical axis among the plurality of lens groups when in the retracted state. A photographing optical system is formed by the remaining lens group excluding, so that photographing is possible.

  The subject image formed on the CCD 120 via the photographing lens 110 and the lens shutter unit 179 is converted into an analog image signal by the CCD 120. Here, the lens shutter unit 179 is for suppressing the occurrence of smear due to light when reading an analog signal from the CCD 120.

  Further, the digital camera 1 includes an auxiliary light emitting unit 130 and a finder 13, and the auxiliary light emitting unit 130 emits auxiliary light from the auxiliary light emitting window 12 at low illuminance. The auxiliary light emitting unit 130 can emit light when necessary other than low illuminance.

  In this digital camera 1, when “normal” is selected by the power switch 15, if the auxiliary light emitting unit 130 is being charged, full-pressing with the shutter button 14 is not permitted and photography is not possible. When “collapse” is selected by the switch 15 and photographing at the time of collapsing is selected, full-pressing with the shutter button 14 is permitted even when the auxiliary light emitting unit 130 is being charged, and photographing is performed. The finder 13 provided in the digital camera 1 is an optical finder as described above. In addition, when “normal” is selected by the power switch 15, this optical finder performs focal length adjustment by the drive circuit 508. This is a zoom finder that performs linked control. On the other hand, when “collapse” is selected by the power switch 15 and photographing at the time of collapse is selected, the finder 13 is adjusted to match the above-described fixed focus angle of view.

  The digital camera 1 includes an analog signal processing unit 501, an A / D unit 502, a digital signal processing unit 503, a temporary memory 504, a compression / decompression unit 505, and a built-in memory (or memory card) 506. An image monitor 20 (see FIG. 1) and a drive circuit 508 are provided. The CCD image sensor 120 is driven at a timing generated by a timing generation circuit (not shown) in the drive circuit 508, and outputs an analog image signal.

  The drive circuit 508 also includes a drive circuit that drives the photographing lens 110, the lens shutter unit 179, the auxiliary light emitting unit 130, and the like. In the drive circuit 508, “normal” is selected by the power switch 15. In this case, the movement of the focus lens (third group) on the photographing optical axis is performed so that the contrast is maximized, but “collapse” is selected by the power switch 15 and photographing when retracted is selected. In this case, the focus lens (third group) is fixed while being arranged so as to be in focus at a distance between 1 m and 2 m from the camera when retracted. The analog image signal output from the CCD image sensor 120 is subjected to analog signal processing by the analog signal processing unit 501, A / D converted by the A / D unit 502, and digital signal processed by the digital signal processing unit 503. Data representing the digital signal processed signal is temporarily stored in temporary memory 504. The data stored in the temporary memory 504 is compressed by the compression / decompression unit 505 and recorded in the built-in memory (or memory card) 506. Depending on the shooting mode, the compression process may be omitted and the recording may be performed directly in the built-in memory 506. Data stored in the temporary memory 504 is read out to the image monitor 20, whereby an image of the subject is displayed on the image monitor 20.

  Further, the digital camera 1 is provided with a CPU 509 for controlling the entire digital camera 1, an operation switch group 510 including a zoom operation switch and the like, and a shutter button 14, and operates the operation switch group 510. Then, the photograph is taken by setting the desired photographing state including setting the desired angle of view and pressing the shutter button 14.

  This is the end of the description of the first embodiment of the present invention, and the following describes another embodiment of the present invention. In each embodiment described below, the appearance of the digital camera is assumed to be the same as that in the first embodiment shown in FIG. 1, and only the characteristic points of each embodiment are described.

  FIG. 18 is a cross-sectional view of a digital camera as the second embodiment of the present invention.

  The cross-sectional view of the digital camera of this embodiment shown in FIG. 18 is a view corresponding to FIG. 14 of the first embodiment, and the difference between this embodiment and the first embodiment is that The group lens 112 is retracted in the recessed portion 104 on the side of the CCD 120, whereas in the present embodiment, it is only retracted on the side of the front group lens 106. The other description of this embodiment is omitted because it overlaps with the description given in the first embodiment.

  Even in the digital camera according to the second embodiment, when the lens barrel is retracted, the rear group lens 112 is retracted while being disposed on the imaging optical axis without having a mechanism for retracting the lens group on the imaging optical axis from the imaging optical axis. In the digital camera equipped with the retractable and retracting mechanism, it is reduced in thickness by being retracted to the side of the front lens group 106 that tends to become a dead space, and the positive refractive power remaining on the photographing optical axis is increased. A fixed-focus imaging optical system is formed by the front lens group 111 and a focus lens that also has a positive refractive power, thereby enabling imaging when retracted.

  FIGS. 19 and 20 are views showing cross sections of the lens barrel in the manipulated state and the retracted state, respectively, of the digital camera according to the third embodiment of the present invention. The lens barrel shown in FIGS. 19 and 20 is a lens barrel in which the tube length can be freely changed between a relatively short tube length storage state and a relatively long tube length photographing state.

  Here, in place of the lens shutter unit 179 (for example, see FIG. 7) using the PZLT element in the first embodiment, a mechanical shutter unit 279 including a mechanical aperture member and a shutter member is provided. Yes. The lens shutter unit 179 in the first embodiment is fixed to the rear group lens holding frame 172 that holds the rear group lens 112 together with the rear group lens 112. The lens shutter unit 279 in the second embodiment is Instead of being fixed to the rear group lens holding frame 172, as shown in FIG. 19, it is fixed to a rear group lens guide frame 170 that rotatably supports the rear group lens holding frame 172. Therefore, as shown in FIG. 20, even if the rear lens group 112 is retracted from the optical axis due to retraction, the lens shutter unit 279 remains on the photographing optical axis. Therefore, in the case of the second embodiment, it is possible to prevent smearing by operating the aperture and the shutter even in the retracted photographing.

  The second embodiment is an example of a digital camera equipped with a CCD 120, but the lens shutter unit 279 stays on the photographing optical axis even when the lens barrel is retracted, and blocks light passing through the lens barrel. Therefore, the present invention can be applied to a camera that takes a picture on a silver salt film.

  In the first embodiment and the second embodiment described above, when the rear lens group 112 is retracted from the photographing optical axis, the lens shutter unit including both the aperture member and the shutter member is also retracted together. In addition, the example in which the lens shutter unit including both the aperture member and the shutter member is held on the photographing optical axis has been described, but the present invention is not limited to this, and the shutter member is provided in the focus lens holding frame. The diaphragm member may be retracted together with the rear group lens, or the diaphragm member may be provided in the focus lens holding frame and the shutter member may be provided in the rear group lens frame. Here, when the diaphragm member remains on the photographing optical axis, the spherical aberration caused by the rear group retraction may be corrected by making the aperture value smaller than that in the normal photographing in the retracted photographing. Further, by reducing the angle of view regardless of the diaphragm member, it is possible to reduce the influence of the field curvature caused by the rear group retract.

  In the first embodiment and the second embodiment, the PLZT element is used as the light amount control member. However, this may use liquid crystal. It is not always necessary to use an electro-optic element, and a mechanical shutter unit that mechanically controls the aperture diameter and shutter speed may be provided. In addition, an iris with a predetermined aperture is advanced and retracted on the photographing optical axis. An iris diaphragm unit may be used.

  Further, in the first embodiment and the second embodiment described above, the digital camera for taking a still image among digital cameras has been described in mind, but the digital camera for taking a moving image, or still image shooting and moving image The present invention can be similarly applied to a digital camera for shooting and shooting.

  In the case where the lens shutter unit is left on the photographing optical axis even when retracted as in the second embodiment, the present invention is also applied to a camera that takes a picture on a silver halide photographic film. Can do.

  Furthermore, in each embodiment, the photographic lens is composed of three groups of a front lens group, a rear lens group, and a focus lens in order from the front in the optical axis direction. The focal length is variable and focus adjustment is performed by moving the focus lens. Although the present invention has been described with reference to an example of a taking lens, the present invention is not limited to this, and the present invention includes a plurality of lens groups including a focus lens arranged on the photographing optical axis, and has a variable focal length and a focus. It can be applied to cameras with a photographic lens that adjusts focus by moving the lens, and at the time of retraction, it can be thinned by retracting at least one of the lens groups from the photographic optical axis. If a fixed focus photographing optical system is formed by the lens group remaining on the photographing optical axis, a plurality of lenses can be used. Which of the group's may be one which retracted from the photographing optical axis.

  FIG. 21 is a diagram showing the arrangement of the lens groups on the photographing optical axis when the photographing lens of the digital camera according to the third embodiment of the present invention is extended and retracted. The left side of FIG. 21 is the objective side, and the CCD image sensor 120 is also shown on the right side of FIG.

  The photographic lens of the third embodiment shown in FIG. 21 is a zoom lens having a two-group configuration including a front group lens 301 and a rear group lens 302.

  FIG. 21A shows the arrangement of the front group lens 301 and the rear group lens 302 during wide-angle shooting, and FIG. 21B shows the front group lens 301 and the rear group lens 302 during telephoto shooting. The arrangement of is shown. FIG. 21C shows the arrangement of the front group and rear group lenses when retracted. Here, the front group lens 301 is retracted from the photographing optical axis, and the rear group lens is shown. Only the state 302 remains on the photographing optical axis is shown.

  As in the first embodiment, the digital camera according to the third embodiment, as described with reference to FIG. 1, means that “normal” is selected by the power switch 15, which means a shooting state. This is a state where an image is formed using all of a plurality of lens groups constituting the lens, and here, photographing when retracted means a retracted state, and the tube length exceeds the shortest tube length state in the photographing state. It is a shortened state.

  That is, when the photographic lens shifts to the retracted position further retracted from the widest position (when the photographic lens shifts to the retracted state), the second lens group retracts from the optical axis, and the retracted position (accommodated state). It becomes possible to shoot with.

  For example, a front lens group and a rear lens group are arranged in order from the front in the optical axis direction, and a photographic lens that has a variable focal length and adjusts the focus is accommodated. In a lens barrel in which the tube length can be freely changed between a shooting state with a long tube length, at least one of the plurality of lens groups is retracted from the shooting optical axis in accordance with the transition to the retracted state. A lens retracting mechanism, and a lens advancing mechanism for advancing the lens group retracted in accordance with the transition to the photographing state onto the photographing optical axis, and the photographing lens is in the retracted state, the plurality of lens groups The remaining lens group excluding the lens group retracted from the photographic optical axis is used to form a photographic optical system to enable photographing.

  In the digital camera according to the present embodiment, as shown in FIG. 21C, when the lens barrel is retracted, the rear group lens 302 remaining on the photographing optical is fixed focus even if the front group lens 301 is retracted from the photographing optical axis. Since the photographing optical system is formed, photographing can be performed even when the lens barrel is retracted. Here, since the front lens group 301 is retracted from the photographing optical axis, the distance between the plurality of lens groups on the photographing optical axis is not retracted when the lens barrel is retracted. Thinning when retracted is achieved rather than simply shrinking. In the digital camera according to the present embodiment, when taking a picture in the retracted state, the angle of view is narrowed in order to avoid that the photographed image is affected by the aberration by photographing only with the rear lens group. The camera is set so that shooting is performed with the aperture stopped.

  The mechanism for retracting the front group lens 301 from the photographing optical axis is applied to the front lens group 301 by applying the mechanism for retracting the rear group lens 112 (see, for example, FIG. 7) in the first embodiment from the photographing optical axis. Well, illustration and description are omitted here.

  Next, a fourth embodiment of the present invention will be described.

  FIG. 22 is a diagram illustrating the arrangement on the photographic optical axis of each lens group when the photographic lens of the digital camera of the fourth embodiment is extended and retracted, corresponding to FIG. 21 in the third embodiment.

  The difference between the present embodiment and the third embodiment is that the digital camera of the present embodiment has a correction lens 303 that stands out of the photographing optical axis during normal photographing and advances on the photographing optical axis only when retracted. It is only a point provided.

  FIG. 22A shows a front lens group 301, a rear lens group 302, and a correction lens 303 that stands by outside the imaging optical axis when the digital camera according to the present embodiment performs wide-angle imaging. 22B shows a front group lens 301, a rear group lens 302, and a correction lens 303 that stands by outside the photographing optical axis when the digital camera according to the present embodiment performs telephoto shooting. That is, in the present embodiment, the correction lens 303 is placed in a state of being retracted from the photographing optical axis during normal photographing.

  FIG. 22C shows the arrangement of the front group and rear group lenses when retracted. Here, instead of retracting the front group lens 301 from the photographing optical axis, the arrangement is made on the photographing optical axis. The correction lens 303 has advanced to the rear side of the rear group lens 302 remaining in FIG.

  The correction lens 303 shown in FIG. 22 is a lens that remains on the photographing optical axis when retracted and serves to correct the aberration of the rear lens group 302 in this embodiment.

  In the digital camera of the present embodiment, as shown in FIG. 22C, even if the front group lens 301 is retracted from the photographing optical axis when retracted, the rear group lens 302 and the correction lens 303 that remain on the photographing optical axis. Since this constitutes a fixed focus photographing optical system, photographing can be performed even when the lens barrel is retracted. Note that, in this embodiment, the shooting with the narrowed field angle and the narrowed aperture setting performed in the third embodiment is set to the widest field angle setting by using this correction lens. can do. In addition, a lens that is sufficiently thin as compared with the front lens group retracted from the photographing optical axis is employed as the correction lens. Since the front lens group 301 is retracted from the photographing optical axis when retracted, the distance between the lens groups on the photographing optical axis is reduced without retracting any lens group when the lens barrel is retracted. Thinning is achieved rather than simply shrinking.

  Note that any known mechanism may be adopted as a mechanism for causing the correction lens 303 to advance on the photographing optical axis when the lens barrel is retracted. For example, the rear lens group in the first embodiment (see, for example, FIG. 7) is used as the photographing optical axis. You may comprise so that it may advance on a photography optical axis at the time of retraction by the mechanism similar to the mechanism retracted | saved from the top.

  Next, a fifth embodiment of the present invention will be described.

  FIG. 23 is an external view of a digital camera 300 according to the fifth embodiment of the present invention.

  FIG. 23A shows the retracted state of the lens barrel 310 provided in the photographing apparatus of the present embodiment, and FIG. 23B shows the extended state of the lens barrel 310 of the digital camera 300. It is shown. FIG. 23C shows the back surface of the digital camera 300.

  The lens barrel 310 of the digital camera 300 shown in FIG. 23 has built-in photographing lenses composed of four groups as described later, and the focal length can be adjusted by moving these lens groups in the optical axis direction. At the same time, focus adjustment is performed by moving the fourth group of focus lenses in the optical axis direction. The lens barrel 310 is a lens barrel that can be freely changed between a storage state with a relatively short tube length and an imaging state with a relatively long tube length.

  An auxiliary light emission window 12 and a viewfinder objective window 13a are arranged at the upper front of the digital camera 300 shown in FIG. A shutter button 14 is arranged on the upper surface of the digital camera 300. The shutter button 14 has two stages of half-press and full-press, and the above-described focus adjustment is performed by half-press, and photographing is performed by full-press. A lens barrier 310a is provided on the front surface of the lens barrel 310 to cover the front surface of the lens barrel 310 when the lens barrel is retracted.

  On the back of the digital camera 1, a power switch 15, a viewfinder eyepiece window 13b, an image monitor 20, a setting display button 16, a recording instruction button 17, an image display on / off button 20a, a cross key 19, and a zoom operation switching button 18 are provided. When the zoom operation mode is entered by continuing to press the zoom operation switch button 18 for a predetermined time, the lens barrel 100 moves to the telephoto side while the mark indicating “up” of the cross key 19 is kept pressed. The lens barrel 310 moves to the wide-angle side while the mark indicating “below” of the cross key 19 is kept pressed. The release of the zoom operation mode is performed again by continuously pressing the zoom operation switching button 18 for a predetermined time.

  The image display on / off button 20a is a button for instructing whether or not to display an image on the image monitor 20. In the digital camera 300, even if the image display on / off button 20a is turned off, the image display on / off button 20a is obtained by photographing. The image is displayed on the image monitor 20 for a predetermined time. Note that shooting when the image monitor 20 is off is performed by checking the object scene from the viewfinder 13.

  The setting display button 16 is a button operated when displaying values such as the currently set shutter speed and sensitivity. The recording instruction button 17 is a button operated when recording a captured image in a memory.

  The viewfinder eyepiece window 13b forms an optical viewfinder between the front viewfinder objective window 13a.

  The power switch 15 is a switch operated to activate the digital camera 300. In the digital camera 1, a position “reproduction” for designating a reproduction mode that is a mode for displaying an image recorded in a memory or the like on the image monitor 20, and a position “ A position “normal” for designating normal photography including “collapse” and movie mode is provided, and the power switch 15 is slidable including a position “OFF” for turning off the power. FIG. 23C shows a state in which the power switch 15 is set to the position “collapse”.

  In this digital camera 300, the lens barrier 310 a is closed using the force by which the power switch 15 is slid from the position “collapse” to the position “OFF”, and the lens barrier is utilized by using the force slid to the position “collapse”. 310a is opened. Therefore, when the power switch 15 is slid from the position “OFF” to the position “normal”, the lens barrier 310 a is opened when passing the intermediate position “collapse”.

  24 to 26 are diagrams showing the arrangement of the lens groups on the photographing optical axis when the photographing lens of the digital camera of this embodiment is extended and retracted.

  24 shows the arrangement of the first to fourth lens groups on the wide angle side when “normal” is selected by the power switch 15, and FIG. 25 shows “normal” by the power switch 15. The arrangement of the first to fourth lens groups on the telephoto side when "" is selected is shown. FIG. 26 shows the arrangement of the lens groups when the lens barrel is retracted when “collapse” is selected by the power switch 15. In the digital camera 300 of the present embodiment, shooting is possible even when “collapse” is selected in addition to the case where “normal” is selected by the power switch 15. Shooting (hereinafter referred to as shooting when retracted) is fixed-focus shooting with the first lens group and the third lens group remaining on the shooting optical axis when the lens barrel is retracted. 24 to 26 also show a CCD on the photographing optical axis.

  When shooting is performed with “normal” selected by the power switch 15, the zoom operation switch described above is operated to adjust the focal length between the tele end shown in FIG. 25 and the wide end shown in FIG. Thus, the desired shooting angle of view is set. The focus lens 440 is focused to a position where the highest contrast can be obtained by contrast detection based on the image signal obtained by the CCD 500. Thereafter, when the shutter button is pressed, an image signal representing the subject at that time is generated by the CCD 500, subjected to appropriate image processing, and recorded.

  In the digital camera of the present embodiment, the case where “normal” is selected by the power switch 15 means a photographing state, and an image is formed using all of a plurality of lens groups constituting the photographing lens. In this case, the retracted shooting means the retracted state, and the tube length is shortened beyond the shortest tube length state in the recorded state.

  That is, when the photographic lens shifts to the retracted position further retracted from the widest position (when the photographic lens shifts to the retracted state), the second lens group retracts from the optical axis, and the retracted position (accommodated state). It becomes possible to shoot with.

  For example, the first lens unit, the second lens unit, the third lens unit, and the fourth lens unit are arranged in order from the front in the optical axis direction, and the photographic lens for adjusting the focal length and adjusting the focus is stored, and the storage state is relatively short. In a lens barrel in which the tube length can be freely changed between a shooting state with a relatively long tube length, at least one of the plurality of lens groups is moved along the shooting optical axis in accordance with the transition to the retracted state. A lens retracting mechanism for retracting from above, and a lens advancing mechanism for retracting the lens group retracted along with the transition to the photographing state on the photographing optical axis, and the photographing lens is Shooting is possible by forming a shooting optical system with the remaining lens groups excluding the lens group retracted from the shooting optical axis among the plurality of lens groups.

  Here, the configuration of the lens barrel 310 will be described with reference to FIGS. 27 to 29 in addition to FIGS.

  As described above, FIG. 24, FIG. 25 and FIG. 26 are sectional views along the optical axis of the lens barrel 310 incorporated in the digital camera shown in FIG. FIG. 27 is a cross-sectional view of the lens barrel in the state shown in FIG. 24 as viewed from the direction of the arrow AA ′ shown in FIG. 24, and FIG. 25 is a cross-sectional view of the lens barrel in the state shown in FIG. 25 viewed from the direction of the arrow BB ′ shown in FIG. 25. FIG. 29 shows the lens barrel in the state shown in FIG. FIG. 27 is a cross-sectional view seen from the direction of the arrow CC ′ shown in FIG. 26. 24 is a sectional view taken along the arrow DD ′ shown in FIG. 27, FIG. 25 is a sectional view taken along the arrow EE ′ shown in FIG. 28, and FIG. 26 is shown in FIG. It is sectional drawing which follows arrow FF '. FIG. 30 is provided on the inner circumference of the outermost cylinder of the three-stage cylinders constituting the lens barrel shown in FIGS. 24 to 29 and on the inner circumference of the middle cylinder of the three-stage cylinders. It is an expanded view explaining the formed cam groove. In the following description, the outermost cylinder of the three-stage cylinder is referred to as a fixed cylinder 313, the middle cylinder of the three-stage cylinder is referred to as an intermediate cylinder 312, and the innermost cylinder is referred to as a front cylinder 311.

  The lens barrel 310 incorporates a zoom lens having a four-group configuration including a first lens group 410, a second lens group 420, a third lens group 430, and a fourth lens group 440. The fourth lens group 440 at the end of the four-group zoom lens is used as a focus lens. In this example, a photographic lens that is composed of a first group, a second group, a third group, and a fourth group in order from the front in the optical axis direction and has a variable focal length and a focus adjustment by the fourth group is provided in the lens barrel. Four groups are formed of lens groups having positive refractive power, negative refractive power, positive refractive power, and positive refractive power, respectively, in order from the first group.

  As shown in FIGS. 24, 25, and 26, the first lens group 410 is held by the front tube 311, and the front tube 311 is provided with a cam pin 3111 (see FIG. 25). The cam pin 3111 is engaged with a cam groove 3123 (see FIGS. 25 and 30) provided on the inner periphery of the intermediate cylinder 312. The intermediate cylinder 312 is also provided with a cam pin 3124, and the cam pin 3124 is engaged with the cam groove 3131 (see FIG. 30) on the inner periphery of the fixed cylinder 313. Further, the rectilinear key 320 is provided with a rectilinear groove 3204 into which the convex portion 3112 of the front cylinder 311 is fitted, and a fitting portion (see FIG. 24) between the convex portion 3112 and the rectilinear groove 3204 is provided in the front cylinder 311. The rotation is stopped. Therefore, the front tube 310 and the straight advance key 320 can only move relative to each other in the optical axis direction and do not rotate around the optical axis.

  Here, the intermediate cylinder 312 is configured to rotate by a zoom motor 3300 (see FIGS. 28 and 29). When the intermediate cylinder 312 is rotated by being driven by the zoom motor 3300, a cam on the inner peripheral surface of the fixed cylinder 313 is formed. The intermediate tube 312 moves in the optical axis direction while rotating along the shape of the groove 3131 (see FIG. 30), and moves forward along the shape of the cam groove 3123 by cam engagement with the intermediate tube 312 that moves while rotating. The cylinder 311 moves in the optical axis direction. FIGS. 28 and 29 show a connection state between the zoom motor 3300 and the intermediate cylinder 312, and a gear 3125 provided on the inner periphery of the intermediate cylinder 312 from the zoom motor 3300 by a connection gear 3302 (see FIG. 28). A configuration in which a rotational force is applied to the intermediate cylinder 312 and the intermediate cylinder 312 rotates is shown.

  Further, a rectilinear key 320 is engaged with the rectilinear groove 3132 of the fixed cylinder 313 so as to freely advance and retract. Further, the cam pin 3203 provided on the rectilinear key 320 is engaged with the cam groove 3122 (see FIG. 30) of the intermediate cylinder 312, so that the intermediate cylinder 312 is rotatably engaged with the rectilinear key 320. Therefore, when the intermediate cylinder 312 advances and retracts with rotation due to the cam engagement with the fixed cylinder 313, the rectilinear key 320 moves forward and backward together with the intermediate cylinder 312.

  In this way, the intermediate cylinder 312 can be relatively rotated around the optical axis, and can be moved integrally with the rectilinear key 320 in the optical axis direction.

  Here, among the lens group holding frames for holding each lens group, the second lens group holding frame 421 for holding the second lens group 420, the fourth lens group holding frame 441 for holding the fourth lens group 440, and the intermediate cylinder 312. , The relationship between the straight key 320 and the third lens group 430, and the relationship between the intermediate cylinder 312 and the fixed cylinder 313 will be described in detail with reference to FIGS. Further, in the example of the present embodiment, a configuration is shown in which the second lens group and the fourth lens group are retracted to the retracted position in order to further shorten the lens barrel. This retracting mechanism will also be described as needed as the relationship between the lens groups is described.

  First, the second lens group holding frame 421 that holds the second lens group 420 is movably supported by a second lens group support frame 422 extending from the rectilinear key 320, and is arranged on the outer periphery of the lens group support frame 422. A cam pin 3211 is provided. The cam pin 3211 is engaged with a cam groove 3121 (see FIGS. 24 and 30) provided on the inner periphery of the intermediate cylinder 312 through the key groove 320 a of the rectilinear key 320. As shown in FIGS. 24 and 30, the straight key 320 supports the second lens group holding frame 421 via the second lens group support frame 422 and directly supports the third lens group 430. Further, the fourth lens group 440 is supported via a moving mechanism including a columnar screw 3201 (see FIG. 25).

  As described above, the second lens group support frame 422 supported by the rectilinear key 320 is provided with the cam pin 3211, and the cam pin 3211 penetrates the key groove 320 a of the rectilinear key 320 and the cam groove of the intermediate cylinder 312. 312 is engaged. When the cam pin 3211 moves along the shape of the cam groove 3121, the second lens group 420 is guided from the key groove 320 a to move from the tele end to the wide end, or from the wide end to the tele end.

  Further, the intermediate cylinder 312 includes a cam pin 3124 planted on the outer periphery thereof, and the cam pin 3124 is engaged with a cam groove 3131 provided on the inner periphery of the fixed cylinder 313. The cam groove 3131 extends a groove (a region indicated by symbol k in FIG. 30) so as to rotate by a predetermined angle while being extended from the retracted state shown in FIG. 26 to the tele end shown in FIG. Accordingly, upon receiving a driving force from the zoom motor 3300 (see FIGS. 28 and 29), the intermediate cylinder 312 follows the cam groove 3131 to obtain a predetermined distance from the retracted state (FIG. 26) to the telephoto end (FIG. 25). While being rotated by an angle, it is fed out in the optical axis direction, and according to the feeding out of the intermediate cylinder 312, the front cylinder 311 is fed out without rotating along the shape of the cam groove 3123 (the area indicated by symbol m in FIG. 30). . If the zoom switch is operated to the wide side while the intermediate cylinder 312 is in the extended state, the intermediate cylinder 312 rotates at that position (indicated by reference numeral 1 in FIG. 30), and the rotation causes The second lens group 420 moves to the wide end along the shape of the cam groove 3121 (the region indicated by reference sign p in FIG. 30). Thus, zooming according to the operation of the zoom switch is performed.

  Here, the second lens group holding frame 421 that holds the second lens group 420 is supported by the second lens group support frame 422, and the second lens group support frame 422 is supported by the rectilinear key 320. The second lens group support frame 422 is provided with a rotating shaft 422a for rotating the second lens group holding frame 421 so that the second lens group holding frame 421 is retracted from the optical axis. On the other hand, the second lens group holding frame 421 is provided with a through hole 422c that fits with the rotation shaft 422a. A rotation shaft 422a is inserted through the through hole 422c of the second lens group holding frame 421, and a spring is provided on the proximal end side of the rotation shaft 422a so that the second lens group holding frame 421 is biased forward of the optical axis. 422b is wound. This spring 422b also has an action of a torsion spring, and is also for urging the second lens group holding frame 421 in the direction of rotation about the rotation shaft 422a. When the lens barrel is retracted, the second lens group holding frame 421 is pressed against the pressing portion 311a of the front tube 311 by the spring 422b, so that the second lens group 420 moves to the base end side and is stored compactly in the lens barrel ( 26), the front lens pressing portion 311a (see FIG. 24) that holds the first lens group 410 is separated from the second lens group support frame 421 during the extension, and the second lens group 420 is lighted by the spring 422b. It is biased forward of the shaft. At this time, the second lens group holding frame 420 is also urged in the rotational direction by the spring 422b so that the center of the second lens group 420 coincides with the optical axis with high accuracy. 4212 contacts the stop rod 4221 and the second lens group is held at the contact position.

  The lens group holding frame 421 is provided with a holding frame 421 on one side and an extending portion 4211 on the other side with the rotation shaft 422a as a boundary. The extending portion 4211 is engaged with the switching convex portion 3133 when the second lens group 420 is retracted together with the rectilinear key 320, and the switching convex portion has a slope along the direction in which the rectilinear key retreats. It is what you have.

  Therefore, when the extended portion 4211 moves along the slope of the switching convex portion 3133 when retracted, the lens group holding frame 421 rotates to a position where the lens group holding frame 421 contacts the straight key 320 around the rotation shaft 422a (see FIG. 29). .

  In this embodiment, the second lens holding frame 421, the extending part 4211 of the holding frame 421, the end part 4212 of the holding frame 421 opposite to the extending part, the torsion spring 421b, and the straight movement A series of members including a stop rod 4221 provided on the second lens group support frame 422 supported by the key 320 and a switching convex portion 3133 provided on the main body side constitute an advance / retreat mechanism of the second lens group 420. ing.

  Further, the third lens group 430 is directly supported by the straight advance key 320, and the straight advance key 320 has a fourth mechanism through a moving mechanism including a focus motor and a columnar screw meshed with a gear head of the focus motor. A lens group 440 is also supported. The fourth lens group 440 is held by a lens group holding frame 441. A through hole 441a is provided in the lens group holding frame 441, and a guide bar 3202 provided in the straight key 320 is inserted into the through hole 441a. Yes. Further, a nut 3201 a that is screwed into the columnar screw 3201 is screwed into the columnar screw 3201, and the nut 3201 a is engaged with a protruding portion 4411 provided on the lens group holding frame 441. On the other hand, a spring 441b is wound around a guide rod 3202 for accurately guiding the lens group holding frame 441 in the optical axis direction, and the lens group holding frame 441 is urged toward the nut 3201a by the spring 441b. .

  In this example, the fourth lens group holding frame 441 is also provided with an advance / retreat mechanism similar to the second lens group holding frame 421, and the extending portion 4411 of the fourth lens group holding frame 441 is a retraction guide 3134. And the fourth lens group 440 retracts from the optical axis in the same manner as the second lens group 420 (see FIG. 26). Then, the first lens group 410 and the third lens group 430 are pushed in as much as possible and packed side by side. Further, the second lens group 420 and the fourth lens group 440 are placed above or below the first lens group 410 and the third lens group 430. It can be packed two-dimensionally, and the lens barrel can be further shortened. In addition, when the lens barrel is in the retracted state shown in FIG. 26, the first lens group 410 and the third lens group 430 form a fixed-focus imaging optical system. It is like that.

  Further, as described above, the focus motor 3200 for moving the fourth lens group 440 in the optical axis direction is also supported by the rectilinear key 320, and the columnar screw 3201 shown in FIG. The rotational driving force of the motor 3200 is transmitted through the gear train, so that the columnar screw 3201 rotates. Along with the rotation, the lens group holding frame 441 engaged with the nut 3201a is moved by the nut 3201a rotatably screwed into the columnar screw 3201 corresponding to the rotation of the columnar screw 3201. Move to adjust the focus.

  Here, based on the image data generated by the image sensor 500, a drive command is issued from a control device (not shown) to the focus motor 3200 supported by the straight key, and the focus is adjusted to perform photographing.

  After the focus adjustment is performed in this way, when the shutter button 304 is pressed, the shutter unit 330 supported by the straight key is driven, and the electronic shutter is further driven to perform photographing. As a result, the subject light that has passed through the first lens group 410, the second lens group 420, the third lens group 430, and the fourth lens group (focus lens) 440 forms an image on the light receiving surface of the image sensor 500, and images are taken. In element 500, an image signal representing a subject image formed on the light receiving surface is generated. 24 to 29 do not show a wiring cable for transmitting a command to the focus motor or the shutter unit.

  In this way, the linear key 320 that moves in the optical axis direction also supports the fourth lens group 440 via the second lens group 240, the third lens group 430, and the columnar screw 3201, and further rotates the columnar screw 3201. By supporting the focus motor 3200, the fourth lens group is moved to the vicinity of the focus together with the linear key, and the position of the fourth lens group is finely adjusted by rotating the column screw at the stage of performing the focus adjustment. It is configured.

  In this case, it is necessary to provide a columnar screw or a guide rod that extends in the optical axis direction from the light receiving surface of the image sensor, and to move the fourth lens group along the guide rod by rotating the columnar screw. Disappears. For this reason, an empty space free of obstructions is generated between the image sensor 500 and the fourth lens group 440. When the lens barrel is retracted, the second lens group 420 and the fourth lens group are retracted from the optical axis to the retracted position in the empty space. 420 can be packed two-dimensionally (see FIG. 26), and the length of the lens barrel can be made much shorter than before. In addition, the front tube 311 is provided with a pressing portion 311a. When the lens barrel is retracted, the second lens group holding frame 421 is pressed toward the second lens group support frame 422 and the spring 422b is contracted to thereby contract the first lens group 410 and the second lens. While moving the group 420 as close as possible, the second lens group can be urged forward by the spring by the spring and extended greatly forward by the optical axis.

  Further, when in the retracted state shown in FIG. 26, the first lens group and the third lens group form a fixed focus photographing optical system. When the retracted state is selected by the selection switch shown in FIG. It can be carried out.

  Then, even if the digital camera 300 shown in FIG. 23 is a thin body, when the lens barrel 310 is retracted, the lens barrel 310 is housed in the camera body, and a lens mirror that holds a zoom lens composed of four groups. When the body 310 is extended from the camera body, the digital camera 300 can enjoy shooting with a high zoom magnification. Further, since the photographing optical system is formed when the lens is in the retracted state, the subject can be photographed in the retracted state as soon as possible even when a photo opportunity occurs during the retracting.

  Finally, the internal configuration of the digital camera of FIG. 23 will be briefly described.

  FIG. 31 is a block diagram showing a circuit configuration of the digital camera of the present embodiment.

  The digital camera 300 includes a zoom lens 400 having a four-group configuration including a first lens group 410, a second lens group 420, a third lens group 430, and a fourth lens group 440 shown in FIGS. 330, a barrier 310a for protecting the photographing lens 400, and an imaging element 500 are provided. The subject image formed on the image sensor 500 via the zoom lens 400 and the shutter unit 330 is converted into an analog image signal by the image sensor 500. Here, the shutter unit 330 includes a diaphragm for limiting the amount of light applied to the image sensor and a shutter for suppressing smear due to light when reading an analog signal from the image sensor 500.

  Further, an auxiliary light emitting unit 600 is provided here, and this auxiliary light emitting unit 600 emits auxiliary light from the auxiliary light emitting unit 600 shown in FIG. 23 toward the front of the digital camera when the luminance is low. Further, the auxiliary light emitting unit 600 can emit light when necessary other than low luminance.

  The digital camera 300 includes an analog signal processing unit 501, an A / D unit 502, a digital signal processing unit 503, a temporary memory 504, a compression / decompression unit 505, and a built-in memory (or memory card) 506. An image monitor 507 and a drive circuit 508 are provided. The image sensor 500 is driven at a timing generated by a timing generation circuit (not shown) in the drive circuit 508, and outputs an analog image signal. The drive circuit 508 also includes a drive circuit that drives the photographing lens 400, the shutter unit, the auxiliary light emitting unit 600, and the like. The analog image signal output from the image sensor 500 is subjected to analog signal processing by the analog signal processing unit 501, A / D converted by the A / D unit 502, and digital signal processed by the digital signal processing unit 503. Image data representing an image after digital signal processing is temporarily stored in temporary memory 504. The image data stored in the temporary memory 504 is compressed by the compression / decompression unit 505 and recorded in the built-in memory (or memory card) 506. Depending on the shooting mode, the compression process may be omitted, and recording may be performed directly in the built-in memory (or memory card) 506. Further, the image data stored in the temporary memory 504 is read out to the image monitor 507, whereby the image of the subject is displayed on the image monitor 507.

  Further, the digital camera 300 is provided with a CPU 509 that controls the entire digital camera 300, an operation switch group 510 including a zoom operation switch, and a shutter button 304, and operates the operation switch group 510. When a desired shooting state including setting a desired angle of view is set and the shutter button 304 is pressed, a picture is taken, that is, the above-described image data is generated.

  In the above embodiment, the fourth lens group 440 and the second lens group 420 are retracted, but only the fourth lens group 440 may be retracted.

  Next, a sixth embodiment of the present invention will be described. In the embodiments described below, the appearance of the digital camera is assumed to be the same as that in the fifth embodiment shown in FIG. 23, and only the characteristic points of each embodiment will be described.

  FIGS. 32 to 37 are views showing the configuration of a lens barrel having an advance / retreat mechanism for retracting the fourth lens group 440. The lens barrel 310 shown in FIGS. 32 to 37 will be described below as being incorporated in the camera shown in FIG. The structure of the lens barrel 310 shown in FIGS. 32 to 37 is the same as that shown in FIGS. 24 to 29 except that the second lens group holding frame 421a is slightly changed.

  32, 33 and 34 are sectional views along the optical axis of the lens barrel 310 incorporated in the digital camera shown in FIG. 32, 33 and 34 show the wide end, tele end and retracted state, respectively. 35 is a cross-sectional view of the lens barrel in the state shown in FIG. 32 as viewed from the direction of the arrow AA ′ shown in FIG. 32, and FIG. 36 is the state shown in FIG. FIG. 37 is a cross-sectional view of the lens barrel of FIG. 33 viewed from the direction of the arrow BB ′ shown in FIG. 33. FIG. 37 shows the lens barrel in the state shown in FIG. It is sectional drawing seen from the direction of arrow CC '. 32 is a cross-sectional view taken along the arrow DD ′ shown in FIG. 35, FIG. 33 is a cross-sectional view taken along the arrow EE ′ shown in FIG. 36, and FIG. 34 is shown in FIG. It is sectional drawing which follows arrow FF '.

  As described above, since the fourth lens group 440 functions as a focus lens group, it is particularly important to align the optical axes. Although description is omitted in the fifth embodiment, the lens holding frame 441 that holds the fourth lens group 440 also advances the fourth lens group 440 with high accuracy to the photographing optical axis in the same manner as the second lens group holding frame 421a. It has a mechanism. The mechanism is the same as that of the second lens holding frame 421a, and the end 4412 of the fourth lens group holding frame 441 is abutted against a stop bar 3205 provided on the linear key 320 so that the center of the focus lens is light. It is configured to coincide with the axis with high accuracy (see FIG. 33). The advance / retreat mechanism in the sixth embodiment also has a torsion spring 441b, a switching convex portion 3134, an extending portion 4411 of the fourth lens group holding frame 441, and its fourth lens group, as in the fifth embodiment. An end 4412 of the holding frame 441 and a stop bar 3205 supported by the rectilinear key 320 are provided. When the fourth lens group 440 is retracted together with the rectilinear key 320, the extended portion 4411 engages with the switching convex portion 3134, and the extending portion 4211 moves along the slope of the switching convex portion 3134. Accordingly, the lens group holding frame 421a rotates about the rotation shaft 422a to a position (see FIG. 34) that contacts the linear key 320. Then, the first lens group 410, the second lens group 420, and the third lens group 430 are pushed in and packed as much as possible, and further, the upper part or the lower part of the first lens group 410, the second lens group 420, and the third lens group 430. The fourth lens group 440 can be packed three-dimensionally, and the lens barrel can be further shortened. Further, a photographing optical system is formed by the remaining lens groups other than the retracted lens group, and a lens barrel capable of photographing even in a retracted state is realized.

  The advancing / retracting mechanism included in the lens barrel may retract the third group lens.

  FIG. 38 is a diagram in which only the configuration of the four-group lens described in FIGS. 24 to 37 is extracted. FIG. 39 shows the arrangement of the lenses when the third lens group of those lens groups is retracted when the lens is retracted. FIG.

  As shown in FIG. 39, the same effect can be obtained by retracting the third lens group having the same positive refractive power as that of the fourth lens group.

  As described above, the lens barrel is shortened by providing an advance / retreat mechanism for retracting at least one of the third lens 430 and the fourth lens group 440 from the photographing optical axis, and the shortened lens mirror is realized. By incorporating the barrel into the photographic device, the photographic device can be made thinner.

  Furthermore, a photographing optical system is formed by the remaining lens groups other than those retracted when retracted, so that a photographing apparatus capable of photographing freely when the lens is retracted is realized.

  In each of the above embodiments, the digital camera has been described as an example. However, the present invention is not limited to this, and a so-called silver salt camera that takes a picture on a roll film or an instant photographic film. There may be. Further, the present invention is not applicable only to a camera, and can be applied to any device as long as the device has a camera function.

  The lens barrel of each of the above embodiments can also be applied to a lens unit such as an interchangeable lens. For example, in a single-lens reflex camera or the like, lenses having different magnifications can be exchanged and used. Among interchangeable lenses used in single-lens reflex cameras, there is an interchangeable lens having a lens barrel with a variable tube length, but the lens barrel of the present invention can also be adopted. As in each of the above embodiments, if at least one lens group of a plurality of lens groups arranged in the lens barrel can be retracted from the photographing optical axis, the interchangeable lens can be thinned, Furthermore, since it is possible to take a picture with the lens group partially evacuated, it is possible to cope with a photo opportunity when carrying the bag.

  The lens unit may be a lens unit integrated with a CCD including a solid-state imaging device or the like.

  In the embodiment described above, an example in which a force for sliding the power switch 15 is used to open and close the lens barrier has been described. However, the present invention is not limited to this, and the power switch 15 is not limited thereto. The lens barrier may be opened and closed according to the detected position, or the lens barrel is moved by sliding the power switch 15 from the position “OFF” to the position “normal”. When the lens barrier is opened and the power switch 15 is slid from the position “normal” to the position “OFF”, the lens barrier is closed together with the lens barrel retracted, and the power switch 15 Is slid to the position “collapsed”, the lens barrier is opened by pressing the shutter button. It may be one that is so.

1 is an external view of a digital camera according to a first embodiment of the present invention. It is the schematic of arrangement | positioning on the imaging | photography optical axis of each lens group at the time of taking-out of a photographic lens, and retracting. It is the schematic diagram which showed the main components seeing the lens barrel in the extended state of the digital camera of 1st Embodiment of this invention from an optical axis direction. FIG. 4 is a diagram showing a fault line A-A ′ on the same sectional view as FIG. 3. FIG. 4 is a diagram showing a fault line D-D ′ on the same sectional view as FIG. 3. It is the figure which showed the tomographic line G-G 'on the same sectional drawing as FIG. FIG. 5 is a cross-sectional view showing a tele end state with the longest focal length along the tomographic line A-A ′ of FIG. 4. FIG. 8 is a diagram showing a fault line F-F ′ on the same sectional view as FIG. 7. FIG. 5 is a cross-sectional view showing a state of the wide end with the shortest focal length along the tomographic line A-A ′ of FIG. 4. FIG. 7 is a cross-sectional view taken along a fault line G-G ′ in FIG. 6. It is sectional drawing which shows the main components of the state of a wide end along the tomographic line D-D 'of FIG. It is the schematic diagram which showed the main components seeing the lens barrel in the retracted state of the digital camera of the first embodiment from the optical axis direction. It is the figure which showed fault line B-B 'and fault line C-C' on the same sectional drawing as FIG. FIG. 14 is a cross-sectional view taken along the fault line C-C ′ of FIG. 13. It is the figure which showed fault line E-E 'on the same sectional drawing as FIG. FIG. 14 is a cross-sectional view taken along the fault line B-B ′ of FIG. 13. It is a block diagram which shows the circuit structure of the digital camera of 1st Embodiment. It is sectional drawing of 2nd Embodiment of the digital camera of this invention. It is a figure which shows the lens barrel cross section of the operation state of the digital camera of 3rd Embodiment of this invention. It is a figure which shows the lens barrel cross section of the retracted state of the digital camera of 3rd Embodiment of this invention. It is a figure which shows arrangement | positioning on the imaging | photography optical axis of each lens group at the time of extension and retracting of the imaging lens of the digital camera of 3rd Embodiment. It is a figure which shows arrangement | positioning on the imaging | photography optical axis of each lens group at the time of extending and retracting of the imaging lens of the digital camera of 4th Embodiment. It is an external appearance perspective view of the digital camera 300 which is 5th Embodiment of the imaging device of this invention. FIG. 24 is a cross-sectional view of the lens barrel 310 incorporated in the digital camera shown in FIG. 23 along the optical axis, showing a state when the lens barrel is at the wide end. FIG. 24 is a cross-sectional view of the lens barrel 310 incorporated in the digital camera shown in FIG. 23 along the optical axis, showing a state when the lens barrel is at the tele end. FIG. 24 is a cross-sectional view of the lens barrel 310 incorporated in the digital camera shown in FIG. 23 along the optical axis, showing a state in which the lens barrel is retracted. It is the figure which cut | disconnected the lens barrel along the line in the figure shown in FIG. 24, and was seen from the direction of the arrow. It is the figure which cut | disconnected the lens barrel along the line in the figure shown in FIG. 25, and was seen from the direction of the arrow. It is the figure which cut | disconnected the lens barrel along the line in the figure shown in FIG. 26, and was seen from the direction of the arrow. It is an expanded view explaining the cam groove provided in the inner periphery of the intermediate | middle cylinder. It is a block diagram which shows the circuit structure of the digital camera of this embodiment. It is sectional drawing which follows the optical axis of the lens barrel 310 in which the advance / retreat mechanism of the second lens group is omitted, and is a diagram showing a state when the lens barrel is at the wide end. It is sectional drawing which follows the optical axis of the lens barrel 310 in which the advance / retreat mechanism of the second lens group is omitted, and is a diagram showing a state when the lens barrel is at the tele end. It is sectional drawing which follows the optical axis of the lens barrel 310 in which the advance / retreat mechanism of the second lens group is omitted, and is a diagram showing a state in which the lens barrel is retracted. It is the figure which cut | disconnected the lens barrel along the line in the figure shown in FIG. 32, and was seen from the direction of the arrow. It is the figure which cut | disconnected the lens barrel along the line in the figure shown in FIG. 33, and was seen from the direction of the arrow. It is the figure which cut | disconnected the lens barrel along the line in the figure shown in FIG. 34, and was seen from the direction of the arrow. It is the figure which extracted only the structure of the 4 group lens demonstrated in FIGS. It is a layout figure showing arrangement of a lens at the time of retracting the 3rd lens group of those lens groups at the time of retraction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Digital camera 12 Auxiliary light emission window 13 Finder 13a Finder objective window 13b Finder eyepiece window 14 Shutter button 15 Power switch 16 Setting display button 17 Record display button 18 Zoom operation switch button 19 Cross key 20 Image monitor 20a Image display button 100 Lens mirror Body 100a Barrier 101 Internal space 102 Opening 103 Wall member 104 Recessed portion 105 Columnar gear 106 Front group lens side 110 Shooting lens 111 Front group lens 112 Rear group lens 113 Focus lens 120 CCD solid-state imaging device 131 Feed screw 132 Nut member 133 Focus lens Guide frame 134 Focus lens holding frame 140 Fixed cylinder 141 Cam groove 142 Key groove 150 Rotating cylinder 151 Gear 152 Cam pin 154 Fixed cylinder side rectilinear key Ring 155 Key plate 156 Cam groove 157 Cam groove 158 Linear key groove 160 Intermediate cylinder 161 Cam pin 164 Intermediate cylinder side linear key ring 165, 166 Cam groove 170 Rear group lens guide frame 171 Cam pin 172 Rear group lens holding frame 173 Rotating shaft 174 Coil spring 175 Lever member 175a End 176 Rotating shaft 177 Engaging pin 178 Engaging groove 179 Lens shutter unit 180 Front group lens frame 205 Guide rod 206 Rotating shaft 209 Convex portion 209a Tapered surface 279 Lens shutter unit 301 Front group lens 302 Rear group lens 303 Correction lens 310 Lens barrel 311 Front cylinder 3111 Cam pin 312 Intermediate cylinder 3121 Cam groove 3122 Cam groove 3123 Cam groove 3124 Cam pin 313 Fixed cylinder 3131 Cam groove 320 Straight key 3 200 Focus Motor 3201 Columnar Screw 3202 Connecting Gear 3203 Cam Pin 400 Shooting Lens 410 First Lens Group 420 Second Lens Group 421 Lens Group Holding Frame 430 Third Lens Group 440 Fourth Lens Group 441 Lens Group Holding Frame 500 Imaging Element

Claims (8)

In order from the front in the optical axis direction, including at least a variable power lens group and a focus adjustment lens group, the first lens unit, the second lens unit, the third lens unit, and the fourth lens unit are accommodated, and the tube length is relatively short. In a lens barrel in which the tube length can be freely changed between the housed state and the relatively long shooting state,
Along with the transition to the retracted state, at least the retracting lens group that is one of the third group and the fourth group of the plurality of lens groups is retracted from the photographing optical axis, and the transition to the photographing state is performed. Along with this, a lens advancing / retreating mechanism for advancing the retracting lens group on the photographing optical axis,
The lens advance / retreat mechanism is:
A spring member for rotating the retractable lens group in a predetermined first rotation direction;
A cam mechanism that rotates in a second rotation direction opposite to the first rotation direction against a biasing force of the spring member in accordance with a change in the tube length ;
2. The lens barrel according to claim 1, wherein the photographic lens forms a photographic optical system with the remaining lens groups excluding the retractable lens group retracted from the photographic optical axis when in the retracted state .   The cam mechanism includes a first member having a slope inclined in an oblique direction with respect to the photographic optical axis, and abuts on the slope according to a change in tube length to rotate the retractable lens group to a second position. The lens barrel according to claim 1, further comprising a second member that rotates in a rotation direction.   The first group, the second group, the third group, and the fourth group are lens groups having positive refractive power, negative refractive power, positive refractive power, and positive refractive power, respectively. The lens barrel according to claim 1. 2. The lens barrel according to claim 1, wherein the photographing lens forms a fixed focus photographing optical system by the remaining lens group when in the retracted state. In an imaging device that captures images by capturing subject light,
An imaging lens composed of a first group, a second group, a third group, and a fourth group in order from the front in the optical axis direction, including at least a variable magnification lens group and a focus adjustment lens group;
A lens barrel that houses the photographic lens, and that can be extended and retracted, and that allows the photographic lens to perform focal length adjustment and focus adjustment when extended;
The lens barrel retracts the retracting lens group including at least one of the third group and the fourth group from the photographing optical axis in accordance with the transition to the retracted state. A lens advancing / retreating mechanism that advances the retractable lens group on the photographing optical axis in accordance with the transition to the photographing state,
The lens advancing / retracting mechanism includes a spring member that rotates the retractable lens group in a predetermined first rotation direction, and the first rotation against the urging force of the spring member as the tube length changes. And a cam mechanism that rotates in a second rotation direction opposite to the direction,
The photographing lens, said when in the accommodated state, the photographing apparatus characterized in that forming the imaging optical system by the remaining lens groups except the retractable lens group retracted from the photographing optical axis. The cam mechanism has a first member having a slope inclined in an oblique direction with respect to the photographing optical axis, and rotates in contact with the slope according to a change in tube length, thereby moving the retracting lens group to the second. The imaging device according to claim 5, further comprising: a second member that rotates in the rotation direction . The first group, the second group, the third group, and the fourth group are lens groups having positive refractive power, negative refractive power, positive refractive power, and positive refractive power, respectively. The imaging device according to claim 5 . 6. The photographing apparatus according to claim 5 , wherein the photographing lens forms a fixed focus photographing optical system by the remaining lens group when in the retracted state .

Images