JP2008151938A - Lens barrel and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel of collapsible type, the lens barrel being designed so that noise is decreased during driving of a lens and the lens barrel is made more compact. <P>SOLUTION: The lens barrel comprises: a cam cylinder disposed in a fixed cylinder so as to freely rotate; a first actuator for rotating the cam cylinder; a moving cylinder moved in the direction of an optical axis relative to the fixed cylinder by the rotation of the cam cylinder; a lens holding frame disposed in the moving cylinder so as to freely move in the direction of an optical axis, and holding the lens; a cam member disposed in the moving cylinder so as to freely rotate and used to move the lens holding frame in the direction of the optical axis; a second actuator disposed in the moving cylinder and used to rotate the cam member; and a position detecting means disposed between the lens holding frame and the moving cylinder and used to detect the position of the lens frame relative to the movable cylinder. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a so-called retractable lens barrel and an imaging apparatus such as a digital still camera, a video camera, and a film camera having the lens barrel.

  In an imaging apparatus such as a compact digital still camera, a retractable lens barrel is mounted in which the lens barrel is housed in the imaging apparatus body when the imaging apparatus is not used (powered off).

In a conventional collapsible type lens barrel, the cam ring is rotated around the optical axis by one motor, so that the movable cylinder engaged with the cam groove formed in the cam ring and the lens therein are retracted, The zoom area is moved from the wide-angle end to the telephoto end (see Patent Document 1).
JP 2002-350706 A

  Here, in the lens barrel of Patent Document 1, when zooming between a wide angle and a telephoto is performed, the lens ring is moved by rotating the cam ring by driving a stepping motor. At this time, since the gear provided on the rotating shaft of the stepping motor is connected to the gear portion formed on the cam ring via a gear mechanism including a plurality of reduction gear trains, the gear mechanism and each part of the gear generate sound such as gear noise. There is a problem that occurs. The sound generated in the mechanism section becomes noise particularly during voice recording during moving image shooting. Therefore, it is desired to reduce the sound generated in the mechanism unit during the zoom operation.

  Further, when there are a plurality of lenses that are driven in the optical axis direction in the moving cylinder during zooming, if the plurality of lenses are driven by the cam ring that drives the moving cylinder, the number of cam grooves provided in the optical axis direction is reduced. Therefore, the length of the cam ring in the optical axis direction increases. This leads to an increase in the size of the imaging device.

  An object of the present invention is to reduce the generation of sound in a zoom mechanism during a zoom operation, and to reduce the size of a lens barrel.

  The lens barrel of the present invention includes a cam barrel that is rotatable with respect to the fixed barrel, a first actuator that rotates the cam barrel, and moves in the optical axis direction with respect to the fixed barrel by the rotation of the cam barrel. A movable cylinder, a lens holding frame which is provided in the moving cylinder so as to be movable in the optical axis direction, and a lens holding frame which holds the lens, and is provided in the movable cylinder so as to be rotatable, and moves the lens holding frame in the optical axis direction. A cam member to be moved, a second actuator provided in the movable cylinder for rotating the cam member, and a position of the lens frame relative to the movable cylinder provided between the lens holding frame and the movable cylinder. And a position detecting means, wherein the cam member is rotated by operating the second actuator without operating the first actuator.

  According to the present invention, it is possible to reduce the generation of sound in the zoom mechanism during the zoom operation, and it is possible to reduce the size of the lens barrel and the imaging device.

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

  1 to 9 show a configuration of a lens barrel for a digital still camera according to an embodiment of the present invention.

  FIG. 1 shows an exploded view of the lens barrel, and FIG. 2 shows a retracted state of the lens barrel. 1 and 2 also show a part of the electric circuit of the digital still camera. In FIG. 2, reference numeral 50 denotes a digital still camera body (imaging apparatus body: hereinafter referred to as a camera body).

  3 shows a wide (wide angle end) state of the lens barrel, FIG. 4 shows a middle zoom state, and FIG. 5 shows a tele (telephoto end) state. Further, FIGS. 6 and 7 are assembled perspective views of the movable cylinder unit in which a peripheral wall of the movable cylinder, which will be described later, is partially cut out and a part of the parts is omitted.

  In these drawings, reference numeral 1 denotes an image sensor holder that supports the entire lens barrel and has an image sensor mounting portion 1a. As shown in FIG. 2, an imaging element 40 such as a CCD sensor or a CMOS sensor is attached to the imaging element mounting portion 1a. An output signal from the image sensor 40 is converted into a digital signal by the A / D converter 63 and then input to the image processing circuit 61. The image processing circuit 61 generates an image signal from the input digital signal. The image signal is sent to the recording circuit 62 where it is recorded on a recording medium such as a semiconductor memory. The image signal is displayed as an image on a display (not shown) such as an LCD.

  Reference numeral 2 denotes a first moving lens composed of a first lens 2a and a second lens 2b, which is a photographic lens arranged on the most object side among other photographic lenses described later. 3 is a second moving lens, and 4 is a third moving lens.

  Reference numeral 5 denotes a guide cylinder as a fixed cylinder fixed to the image sensor holder 1. The image sensor holder 1 and the guide tube 5 are fixed inside the camera body 50. With respect to the guide tube 5 (that is, with respect to the camera body), the movable tube described later has a retracted state (collapsed state) shown in FIG. 2 and a wide position as a photographable state (projecting position) shown in FIG. It moves forward and backward in the direction of the optical axis.

  A cam ring 6 is rotatably attached to the outer periphery of the guide tube 5. A rib portion 6 a extending in the circumferential direction is formed on the inner periphery of the cam ring 6. The rib part 6a is bayonet-coupled between the abutting part 5a provided at the front end (object-side end) of the guide cylinder 5 and the protrusion part 5b provided behind the abutting part 5a. Thereby, the movement of the cam ring 6 with respect to the guide tube 5 in the optical axis direction is prevented.

  A stepping motor unit 30 includes a stepping motor 30a as a first actuator, and a reduction gear mechanism (deceleration gear train) that reduces the output from the stepping motor 30a and transmits it to the large gear portion 6a of the cam ring 6. It is configured. The stepping motor unit 30 is fixed to the image sensor holder 1. The stepping motor 30a operates in accordance with a drive signal transmitted from the control circuit 60 shown in FIGS. 1 and 2 via a flexible printed board (not shown). The control circuit 60 controls the operation of the entire camera, and also controls the operations of the image processing circuit 61 and the recording circuit 62 described above.

  Reference numeral 8 denotes a front lens holding frame that holds the first lens 2a, and 9 denotes a first moving lens holding frame that holds the front lens holding frame 8 and holds the second lens 2b. The front lens holding frame 8 is optically adjusted with respect to the first moving lens frame 9 in the completed state of the lens barrel. Specifically, the front lens holding frame 8 is held so as to be decentered with respect to the first moving lens holding frame 9 in a direction orthogonal to the optical axis AXL (see FIGS. 2 to 5). The eccentricity adjustment can be performed so that the cylinder is in a good optical state. After the adjustment, the front lens holding frame 8 and the first moving lens holding frame 9 are joined by adhesion or the like.

  Reference numeral 7 denotes a moving cylinder. The moving cylinder 7 accommodates the first moving lens 2 and the second moving lens 3 inside thereof so as to be movable in the optical axis direction. A tapered roller (cam follower) 10 is fixed to the outer periphery of the movable cylinder 7. The tapered roller 10 is fitted into a guide groove 5c formed in the guide tube 5 so as to extend in the optical axis direction, and is engaged with a cam groove 6b formed on the inner periphery of the cam ring 6.

  Reference numeral 11 denotes a decorative ring fixed to the front lens holding frame 8, which blocks external light from the space between the front lens holding frame 8 and the first moving lens holding frame 9 and the moving cylinder 7. Reference numeral 12 denotes a dust entry prevention ring wound around the outer periphery of the decorative ring 11.

  Reference numerals 13, 14, and 15 denote guide bars (guide members) extending in the optical axis direction. The front end portions of the guide bars 13, 14 and 15 are held by holding portions 7 b and 7 c provided in the movable cylinder 7, and the rear end portions are held by a metal plate 16 coupled to the rear end portion of the movable cylinder 7. Has been. The metal plate 16 is positioned with respect to the moving cylinder 7 by a positioning dowel 7 a provided at the rear end of the moving cylinder 7.

  The first moving lens holding frame 9 has a sleeve portion 9a that is movably engaged with the guide bar 14 in the optical axis direction, and a U-groove portion 9b that is movably engaged with the guide bar 15 in the optical axis direction. The first moving lens holding frame 9 (first moving lens 2) is guided in the optical axis direction by the engagement of the sleeve portion 9a and the guide bar 14, and the first movement lens holding frame 9 is engaged by the engagement of the U groove portion 9b and the guide bar 15. The moving lens holding frame 9 is prevented from rotating around the guide bar 14.

  Reference numeral 17 denotes a second moving lens holding frame that holds the second moving lens 3. The sleeve portion 17a provided on the second moving lens holding frame 17 is engaged with the guide bar 13 so as to be movable in the optical axis direction, and the U groove portion 17b is engaged with the guide bar 15 so as to be movable in the optical axis direction. . The second moving lens holding frame 17 is guided in the optical axis direction by engagement between the sleeve portion 17 a and the guide bar 13, and is guided by the engagement between the U groove portion 17 b and the guide bar 15. Rotation about the bar 13 is prevented.

  A cylindrical cam 24 moves the first moving lens holding frame 9 and the second moving lens holding frame 17 in the optical axis direction. The front end portion of the cylindrical cam 24 is rotatably held by a bearing portion 7 a provided in the movable cylinder 7, and the rear end portion thereof is rotatably held by a metal plate 16. The cylindrical cam 24 is formed with a first cam groove 24a for driving the first moving lens 2 in the optical axis direction and a second cam groove 24b for driving the second moving lens 3 in the optical axis direction. ing. A taper pin (cam follower) 9c provided integrally with the first moving lens holding frame 9 is engaged with the first cam groove 24a. A taper pin (cam follower) 17c provided integrally with the second moving lens holding frame 17 is engaged with the second cam groove 24b.

  Here, as shown in FIG. 6, in the movable cylinder 7, the sleeve portions 9 a and 17 a (guide bars 14 and 13) of the first and second movable lens holding frames 9 and 17 are the first and second movable lenses. It is arranged in a space above two or three. Further, the sleeve portions 9 a and 17 a are disposed on both sides in the radial direction of the cylindrical cam 24 so as to be close to the cylindrical cam 24. Further, the taper pins 9c and 17c are provided on the sleeve portions 9a and 17a as shown in FIGS. 6, 1 and 2, respectively. With such an arrangement, the first moving lens holding frame 9 and the second moving lens holding frame 17 can be stably driven in the optical axis direction by the cylindrical cam 24, and these can be moved into the moving cylinder 7. It can be arranged compactly, that is, in a space efficient manner.

  Reference numeral 25 denotes a stepping motor as a second actuator. A pulley gear portion 25 a is attached to the output shaft of the stepping motor 25. A timing belt 31 is wound around the pulley gear portion 25 a and the gear portion 24 c formed on the cylindrical cam 24. For this reason, when the stepping motor 25 rotates, the driving force is transmitted to the cylindrical cam 24 via the timing belt 31 to rotate it. When the cylindrical cam 24 rotates, the first moving lens holding frame 9 and the second moving lens holding frame 17 whose taper pins 9c and 17c are engaged with the first and second cam grooves 24a and 24b are driven in the optical axis direction. Is done.

  The stepping motor 25 is attached to a flange portion 7 d provided on the movable cylinder 7. Accordingly, the stepping motor 25, the cylindrical cam 24, and the timing belt 31 move in the optical axis direction integrally with the movable cylinder 7. Further, the stepping motor 25 operates when a drive signal is transmitted from the control circuit 60 via a flexible printed board (not shown).

  32a is a photo interrupter as position detecting means, and has a light projecting element and a light receiving element (not shown) that constitute a light projecting / receiving unit of the photo interrupter. The photo interrupter 32a turns on / off the output signal by switching between the light-transmitting state and the light-blocking state by the light-blocking wall 7e provided in the movable cylinder 7. The light shielding wall 7e can be inserted into and removed from the light projecting / receiving portion of the photo interrupter 32a. By monitoring these output signals, the control circuit 60 can detect the absolute positions of the first moving lens 2 and the second moving lens 3. The photo interrupter 32 a is fixed to the second moving lens holding frame 17.

  A diaphragm unit 22 is attached to the second moving lens holding frame 17 and moves together with the second moving lens holding frame 17 in the optical axis direction. An aperture motor 23 drives the aperture unit 22. The aperture motor 23 is operated by a drive signal transmitted from the control circuit 60 via the flexible printed board described above.

  Moving cylinder 7, first moving lens holding frame 9 (first moving lens 2), second moving lens holding frame 17 (second moving lens 3), guide bars 13 to 15, stepping motor 25, cylindrical cam 24, diaphragm The unit 22, the aperture motor 23 and the photo interrupter 32a constitute a moving cylinder unit.

  Reference numerals 19 and 20 denote guide bars extending in the optical axis direction. The rear end portions of the guide bars 19 and 20 are held by holding portions 1 b and 1 c provided on the image sensor holder 1, and the front end portions are held by a metal plate 21 coupled to the front end portion of the image sensor holder 1. Yes. The metal plate 21 is positioned with respect to the image sensor holder 1 by a positioning dowel 1 d provided at the front end of the image sensor holder 1.

  A third moving lens holding frame 18 holds the third moving lens 4. The sleeve portion 18a provided on the third moving lens holding frame 18 is engaged with the guide bar 19 so as to be movable in the optical axis direction, and the U groove portion 18b is engaged with the guide bar 20 so as to be movable in the optical axis direction. Yes. The third moving lens holding frame 18 (third moving lens 4) is guided in the optical axis direction by the engagement between the sleeve portion 18a and the guide bar 19, and the third movement is performed by the engagement between the U groove portion 18b and the guide bar 20. The rotation of the lens holding frame 18 around the guide bar 19 is prevented.

  Reference numeral 26 denotes a rack attached to the third moving lens holding frame 18, and 27 denotes a stepping motor for moving the third moving lens 4 in the optical axis direction. A feed screw portion 28 is formed on the output shaft of the stepping motor 27, and the rack 26 is engaged with the feed screw portion 28. Therefore, when the stepping motor 27 rotates, the third moving lens holding frame 18 is driven in the optical axis direction by the meshing action of the feed screw portion 28 and the rack 26.

  A motor holding member 29 holds the stepping motor 27 and the feed screw portion 28, and is fixed to the image sensor holder 1 from the optical axis direction by a motor fixing portion 29a. The stepping motor 28 operates by receiving a drive signal transmitted from the control circuit 60 via a flexible printed board (not shown). The control circuit 60 controls the stepping motor 27 while detecting the position of the third moving lens holding frame 18 by the photo interrupter 32 b attached to the image sensor holder 1. The photo interrupter 32b turns on / off the output signal by switching between the light transmitting state and the light blocking state by the light blocking wall 18c provided in the third moving lens holding frame 18. By monitoring these output signals, the control circuit 60 can detect the absolute position of the third moving lens 4.

  The imaging cylinder holder 1, the guide cylinder 5, the cam ring 6, the third moving lens holding frame 18 (third moving lens 4), the guide bars 19 and 20, the stepping motor 27, the stepping motor unit 30, and the photo interrupter 32b Unit is configured. The fixed barrel unit and the above-described movable barrel unit constitute a collapsible lens barrel.

  Next, the operation of the lens barrel configured as described above will be described. When a drive signal is transmitted from the control circuit 60 to the stepping motor 30a in order to change from the retracted state shown in FIG. 2 to the wide state shown in FIG. 3, the stepping motor 30a is actuated, and its output is camped via the reduction gear mechanism 30b. It is transmitted to the large gear portion 6d of the ring 6. As a result, the cam ring 6 rotates around the optical axis with respect to the guide tube 5. Since the movable cylinder 7 is prevented from rotating around the optical axis by the engagement between the tapered roller 10 and the guide groove 5c of the guide cylinder 5, the engaging action between the tapered roller 10 and the cam groove 6b of the cam ring 6 is prevented. Is driven in the direction of the optical axis. As a result, the movable cylinder 7 moves from the retracted position to the wide position in FIG.

  FIG. 8 shows the cam groove 6b of the cam ring 6 developed in the circumferential direction. The cam ring 6 is formed with three cam groove portions 6b at equal intervals in the circumferential direction (left-right direction in the figure). The upper side of the figure is the object side. 8, the position of the tapered roller 10 indicated by 6 c corresponds to the retracted state of FIG. 2, and the position of the tapered roller 10 indicated by 6 d corresponds to the wide, middle zoom, and tele states shown in FIGS. 3, 4, and 5. To do. In other words, the movable cylinder 7 (movable cylinder unit) is driven back and forth in the optical axis direction by the cam groove 6b in the retracted (accommodating) area between the retracted position and the wide position, and photographing between the wide position and the tele position is possible. In the area (zoom area), it is stopped without being advanced or retracted.

  FIG. 9 shows the first and second cam grooves 24a and 24b of the cylindrical cam 24 developed in the circumferential direction. The first and second cam grooves 24a and 24b are formed one by one in the optical axis direction (vertical direction in the figure). The upper side of FIG. 9 is the object side. In the retracted state shown in FIG. 2, the taper pin 9 c provided on the first moving lens holding frame 9 is engaged with the first cam groove 24 a at a position indicated by 24 e in the drawing, and the second moving lens holding frame 17. The taper pin 17c provided on the second cam groove 24b is engaged with the second cam groove 24b at a position indicated by 24g in the figure.

  Here, the engagement positions 24e and 24g with the first and second cam grooves 24a and 24b are both engagement positions in the tele state shown in FIG. In the state of being in the engagement positions 24e and 24g, since the first moving lens group 2 and the second moving lens 3 are closest to each other on the front end side of the moving cylinder 7, this engagement position is adopted even in the retracted state. The length of the retracted lens barrel in the optical axis direction is minimized.

  Therefore, when shifting from the retracted state of FIG. 2 to the wide state of FIG. 3, the stepping motor 30a is operated to move the movable cylinder 7 to the object side, and the stepping motor 25 is also operated. Then, the stepping motor 25 is operated until the photo interrupter 32a is switched from the light shielding state to the light transmitting state, the engagement position is switched, and the detection position 24h is reached, and then the operation is further performed by a predetermined number of pulses. Thereby, the engagement position moves from the positions 24e and 24g in the retracted state (tele state) to the positions 24d and 24f in the wide state.

  At this time, the first moving lens holding frame 9 is driven in the optical axis direction by the engaging action of the first cam groove 24a and the taper pin 9c while being guided and prevented from rotating by the guide bars 14 and 15. Further, the second moving lens holding frame 17 is driven in the optical axis direction by the engaging action of the second cam groove portion 24b and the taper pin 17c while being guided and blocked by the guide bars 13 and 15.

  At the same time, the control circuit 60 transmits a drive signal to the stepping motor 27 to operate it, and moves the third moving lens holding frame 18 to the position of the wide state shown in FIG.

  In order to change from the wide state to the middle zoom and tele states shown in FIGS. 4 and 5, respectively, the stepping motor 30 is operated without operating the stepping motor 30, that is, without rotating the cam ring 6, and the first step is performed. The second moving lens holding frames 9 and 17 are moved within the moving cylinder 7. At the same time, the stepping motor 27 is operated to move the third moving lens holding frame 18 to the middle zoom and tele positions.

  In the lens barrel of the present embodiment, when zooming between the wide state and the tele state, the first and first steps are performed using the stepping motor 25 and the cylindrical cam 24 without driving the cam ring 6 via the reduction gear train. The zoom is performed by moving the two moving lenses 2 and 3. As a result, it is possible to reduce the noise as in the case of the video camera lens as compared with the case where the driving force of the stepping motor is transmitted to the cam ring via the reduction gear train to drive the first and second moving lenses. Further, since the cam ring 6 is not rotated, the generation of sliding noise with the guide tube 5 can be prevented, and further noise reduction can be achieved.

  Further, in this embodiment, since the two moving lenses 2 and 3 are driven in the moving cylinder 7 without using the cam ring 6, compared to the configuration in which the two moving lenses are driven using the cam ring, The cam ring can be downsized, and the camera can be downsized.

  In this embodiment, since the stepping motor 25 and the cylindrical cam 24 are provided in the movable barrel 7 together with the movable lenses 2 and 3, there is no special protrusion on the outer surface of the lens barrel, and the lens barrel is large. It is possible to reduce the noise of the zoom drive without making it.

  FIG. 10 is a flowchart showing the control related to the operation of the lens barrel by the control circuit 60 of the camera of this embodiment. This control is executed according to a computer program stored in the control circuit 60 as a microcomputer.

  In step (abbreviated as S in the figure) 101, the control circuit 60 determines whether or not a power switch (not shown) provided in the camera body 50 is turned on. If the power switch is not turned on, the determination in step 101 is repeated, and if the power switch is turned on, the process proceeds to step 102.

  In step 102, the control circuit 60 drives the stepping motor 30a to rotate the cam ring 6, thereby moving the movable cylinder 7 to the wide position. At the same time, in step 103, the stepping motor 25 is driven to rotate the cylindrical cam 24 so that the first and second movable lenses 2 and 3 are moved from the retracted position to the wide position. To move.

  In step 104, the control circuit 60 determines whether or not the photo interrupter 32a as the position detecting means has been switched from the light shielding state (off) to the light transmitting state (on). Then, the stepping motor 25 is driven by a predetermined number of pulses. As a result, the first and second movable lenses 2 and 3 are moved to the wide position, and the photographing is possible.

  Next, in step 106, the control circuit 60 determines whether or not a zoom switch (not shown) provided in the camera body 50 has been operated. When the zoom switch is operated to the tele side, the process proceeds to step 107, and it is determined whether or not the current zoom state is the tele end state. If it is in the tele end state, the process returns to step 106. If not in the tele end state, the process proceeds to step 108 and the stepping motor 25 is driven in the direction in which the first and second movable lenses 2 and 3 are directed to the tele end position by the number of pulses corresponding to the operation of the zoom switch. . Then, the process returns to step 106. Thereby, when the zoom switch is momentarily operated to the tele side, the first and second moving lenses 2 and 3 move toward the tele end direction by an amount corresponding to the operation of the zoom switch. When the operation of the zoom switch to the tele side is continued, the processing from step 106 to step 108 is repeated, and the first and second moving lenses 2 and 3 continuously move toward the tele end.

  If it is determined in step 106 that the zoom switch has been operated to the wide side, the process proceeds to step 109 to determine whether or not the current zoom state is the wide end position. If it is the wide end position, the process returns to step 106. If it is not the wide end, the process proceeds to step 110, and the stepping motor 25 is driven in the direction in which the first and second moving lenses 2, 3 are directed toward the wide end position by the number of pulses corresponding to the operation of the zoom switch. Then, the process returns to step 106. As a result, when the zoom switch is momentarily operated to the wide side, the first and second moving lenses 2 and 3 move toward the wide end by an amount corresponding to the operation of the zoom switch. When the operation of the zoom switch to the wide side is continued, the processing of Step 106, Step 109, and 110 is repeated, and the first and second moving lenses 2 and 3 continuously move toward the wide end. .

  If it is determined in step 106 that the zoom switch has not been operated, the process proceeds to step 111, where it is determined whether or not an operation for turning off (turning off) the power switch has been performed. If the shut-off operation has not been performed, the process returns to step 106. When the shut-off operation is performed, the process proceeds to step 112, and both the stepping motor 30a and the stepping motor 25 are driven so that the movable cylinder 7 and the first and second movable lenses 2 and 3 are directed to the retracted position. Then, when the retracting operation of the lens barrel is completed, this flow is finished.

  In this embodiment, the lens barrel used in the digital still camera has been described. However, the present invention can also be applied to a lens barrel of another photographing apparatus such as a video camera or a film camera.

  Further, in the present embodiment, a case has been described in which one movable cylinder has a one-stage telescopic retractable lens barrel that advances and retracts. However, in the present invention, two or more movable cylinders relatively move forward and backward, and imaging is performed. The present invention can also be applied to a case in which there are two or more retractable retractable lens barrels that move forward and backward with respect to the apparatus main body.

  Further, in the present embodiment, the case where the stepping motor and the cylindrical cam are accommodated in the moving cylinder together with the moving lens has been described. However, the actuator for driving the cylindrical cam is not limited to the stepping motor, and may be a DC motor or a vibration type motor. Good. Alternatively, a linear actuator such as a voice coil motor or a vibration type linear actuator may be accommodated in the moving cylinder together with the moving lens without using the cylindrical cam, and the moving lens may be moved directly in the optical axis direction by the linear actuator.

1 is an exploded perspective view showing a configuration of a lens barrel that is an embodiment of the present invention. Sectional drawing which shows the retracted state of the lens-barrel of an Example. Sectional drawing which shows the wide state of the lens-barrel of an Example. Sectional drawing which shows the middle zoom state of the lens-barrel of an Example. Sectional drawing which shows the tele state of the lens-barrel of an Example. The perspective view which shows the structure of the movement cylinder unit in the lens barrel of an Example. The perspective view which shows the structure of the movement cylinder unit in the lens barrel of an Example. FIG. 3 is a development view of a cam ring in the lens barrel of the embodiment. FIG. 3 is a development view of a cylindrical cam in the lens barrel of the embodiment. 6 is a flowchart illustrating control of a lens barrel of the camera according to the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image pick-up element holder 2 1st moving lens 3 2nd moving lens 4 3rd moving lens 5 Guide cylinder 6 Cam ring 7 Moving cylinder 9 1st moving lens holding frame 17 2nd moving lens holding frame 18 3rd moving lens holding frame 24 Cylindrical cam 25 Stepping motor (second actuator)
30a Stepping motor (first actuator)

Claims (3)

A cam cylinder rotatably provided with respect to the fixed cylinder;
A first actuator for rotating the cam cylinder;
A moving cylinder that moves in the optical axis direction with respect to the fixed cylinder by rotation of the cam cylinder;
A lens holding frame which is provided in the movable cylinder so as to be movable in the optical axis direction and holds a lens;
A cam member which is rotatably provided in the movable cylinder and moves the lens holding frame in the optical axis direction;
A second actuator provided in the movable cylinder and rotating the cam member;
A position detecting means provided between the lens holding frame and the movable cylinder for detecting the position of the lens frame relative to the movable cylinder;
A lens barrel, wherein the cam member is rotated by operating the second actuator without operating the first actuator. The second actuator is a drive mechanism including a stepping motor;
The position detecting means includes
An optical sensor provided on the lens holding frame and having a light projecting and receiving unit;
A light-shielding portion provided on the movable cylinder and inserted into and removed from the light projecting / receiving portion of the optical sensor;
The lens barrel according to claim 1, comprising: The lens barrel according to claim 1 or 2,
An image pickup device comprising: an image pickup device that picks up an image formed by the lens barrel.

Images