JP2006047392A - Optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an optical device which is small-sized and is strong against impact. <P>SOLUTION: The optical device includes; a first member 6; a second member 5 which is disposed on the inner peripheral side of the first member rotatably around an optical axis with respect to the first member 6 and has as first cam part 5d provided on an inner peripheral surface thereof; and a third member 2A which has a first engagement part 2b to be engaged with the first cam part 5d, provided on an outer peripheral surface thereof and is driven in a direction of the optical axis by rotation of the second member 5. The first member 6 has a guide part 6a for guiding the third member 2A in the direction of the optical axis, and the third member 2A is provided with a second engagement part 2c to be engaged with the guide part 6a, and a contact part 2a to be abutted on an object-side end face 5a of the second member 5 is provided on the outer peripheral surface of the third member 2A and is provided on the more inner peripheral side than the second engagement part 5 and within a second radial direction range B including a first radial direction range A provided with the first engagement part 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lens driving structure in an optical apparatus such as a photographing apparatus.

  2. Description of the Related Art Conventionally, an imaging apparatus including a zoom mechanism that can change a photographing magnification is known. This zoom mechanism has a fixed cylinder fixed to the imaging apparatus main body and a cam ring held on the inner diameter of the fixed cylinder, and moves the lens barrel holding the lens in the optical axis direction by the cam ring. Magnification is performed by. The lens barrel is supported on the fixed barrel by three followers each having a tapered cam ring.

  However, when an impact is applied to the lens barrel, there is a problem that the follower is detached from the cam because the follower must cope with the impact.

  Therefore, in Patent Document 1, a rib is formed on the fixed cylinder and a rib is also formed on the moving cam ring, so that the ribs are brought into contact with each other with the moving cam ring extended, thereby protecting the lens barrel. Technology has been proposed.

Also, in Patent Document 2, as in Patent Document 1, a configuration is proposed in which ribs are formed on two members constituting the lens barrel, and the ribs abut against each other in the extended state so that the lens barrel can withstand an impact on the lens barrel. Has been.
JP 2001-324663 A (paragraphs 0031 to 0032, FIG. 3, FIG. 10, etc.) Japanese Patent Laid-Open No. 2003-084187 (paragraphs 0015 to 0023, FIG. 3, FIG. 4, etc.)

  However, in Patent Documents 1 and 2, ribs are provided on the fixed cylinder and the cam ring, so that a space for arranging the rib is required between the fixed cylinder and the movable cam ring, and the outer shape of the lens barrel increases. At the same time, since the ribs come into contact with each other in the extended state of the lens barrel to cope with the impact, there is a problem that the lens barrel cannot be sufficiently protected when the lens barrel is stored.

  An object of the present invention is to realize an optical apparatus having a lens driving structure that is small in size and resistant to impact.

  An optical apparatus according to one aspect of the present invention includes a first member and an inner peripheral surface that is disposed on the inner peripheral side of the first member so as to be rotatable around the optical axis with respect to the first member. A second member provided with a first cam portion, and a first engagement portion that engages with the first cam portion on an outer peripheral surface, and the optical axis direction by rotation of the second member The first member has a guide portion that guides the third member in the optical axis direction, and the third member includes the guide portion. A second engaging portion to be engaged is provided, and an outer peripheral surface of the third member is provided with an abutting portion that abuts on an object side end surface of the second member. Is provided on the inner peripheral side of the second engaging portion and in a second radial range including the first radial range in which the first engaging portion is provided. The features.

  According to the present invention, since the contact portion that contacts the object-side end surface of the second member is provided on the outer peripheral surface of the third member, the strength against external impact is improved, and the corresponding contact portion Is provided on the inner peripheral side of the second engaging portion and in the second radial range including the first radial range in which the first engaging portion is provided. A small optical device which is not necessary can be realized.

  Examples of the present invention will be described below.

  1 to 12 are diagrams illustrating an optical apparatus according to the first embodiment of the present invention, and FIGS. 1 to 5 are external views of an imaging apparatus equipped with the optical apparatus according to the present embodiment. This imaging device 15 is a slide barrier type imaging device in which the front surface of the lens barrel 2 is covered with a barrier 18 and the lens barrel 2 is extended (opened) by sliding the barrier 18 laterally when in use. is there.

  In addition, although the optical apparatus of a present Example demonstrates as an example the lens-barrel mounted in imaging devices, such as a digital camera, a single-lens reflex camera, a video camera, and an analog camera using a silver salt film, other devices and The present invention can also be applied to a device having an optical system such as a device.

  FIG. 1 is an external perspective view showing a state in which the barrier 18 is opened with respect to the camera body. FIG. 2 is an external perspective view showing a state in which the barrier 18 is closed with respect to the camera body. 3 is a top view, FIG. 4 is a bottom view, and FIG. 5 is a rear view.

  A finder 14, a photometric sensor that performs photometry, a sensor unit 13 in which a focus detection sensor is disposed, a red-eye lamp 16, and a strobe unit 17 are disposed on the front surface of the imaging device 15, and the first lens group 1 is further disposed. A lens barrel 2 that is a lens holding member is provided.

  A release switch 11 and a strobe mode button 12 are provided on the top surface of the image pickup device 15, a strap holding portion 20 is provided on the side surface, a tripod mounting portion 21 is provided on the bottom surface, a card battery 22 having a battery inside, and an external input / output terminal portion. 19 is arranged. A memory card drive (not shown) is also provided.

  On the rear side, an operation switch 24, a display 25 having an LCD, a zoom button 23, and a viewfinder eyepiece 14a are arranged. The operation switch 24 selects an operation mode of the imaging device 15 such as a shooting mode, a reproduction mode, and a moving image shooting mode.

  The display 25 as image display means displays image data stored in the memory 34 and image information read from an external storage device such as a memory card on the display screen. When a mode is selected, a plurality of shooting information can be reduced and displayed on the screen.

  As shown in FIG. 6, the imaging apparatus 15 of the present embodiment is provided with a CPU 40, a ROM 39, and a RAM 41 that constitute a control unit, and further, a release switch 11, an operation switch 24, a display 25, and a memory via a bus. 34, various components such as an external storage device 36 provided in the memory card drive are connected.

  Further, a zoom motor drive circuit 26, a focus motor drive circuit 28, and a shutter drive circuit 29 are provided, and this drive circuit drives the motor to drive the zoom lens 3, the focus lens 7, and the shutter 30. In addition, a photometry circuit 13a, a focus detection circuit 13b, and an image sensor 10 such as a CCD sensor or a CMOS sensor are provided. Each circuit and unit is connected to the CPU 40 via a bus, and each is controlled by a signal from the CPU 40. Will be.

  The ROM 39 stores a program for controlling each functional component described above. The RAM 41 stores data necessary for each control program.

  When the user slides the barrier 18 and turns the power button 27 linked to the barrier 18 from OFF to ON, the CPU 40 reads a necessary control program from the ROM 39 and starts an initial operation. That is, after performing the opening operation of the barrier 18, the lens barrel 2 is moved to a predetermined image-capturing area, and a shooting standby state is set.

  When the release switch 11 is pressed to take a picture (when SW1 is turned on), the brightness of the subject is detected by the photometry circuit 13b. Then, based on the measured photometric value, it is determined whether the aperture value, shutter speed, and whether the flash unit 17 emits light. In addition, the user can select whether the flash unit 17 is forced to emit light or not by using the operation switch 24 in advance.

  Next, focus detection is performed by the focus detection circuit 13b, the distance to the subject is measured, and the focus motor drive circuit 28 is driven to move the focus lens 7 to a predetermined focus position. Next, the shutter 30 is opened and closed to form a subject image on the image sensor 10.

  Charges corresponding to the amount of incident light are accumulated in the image sensor 10 based on the exposure control value, and the charges become image signals that are output to the A / D conversion circuit 32 via the image pickup circuit 31. The A / D conversion circuit 32 converts the captured analog image information into digital image information. This digital image information is output to the image processing circuit 33, where the digital image information is processed. Finally, the digital image information is stored in the memory 34.

  The image information stored in the memory 34 is subjected to compression processing such as JPEG or TIFF by the compression / decompression circuit 35 by operating the operation switch 24, and is stored in the external storage device attached to the memory card drive 36. . If the imaging device 15 does not have the memory 34, the digital image information processed by the image processing circuit 33 may be output to the compression / expansion means 35 and stored directly in the external storage device of the memory card drive 36. Good.

  The image information stored in the memory 34 or the external storage device is decompressed by the compression / expansion means 35 and can be displayed on the display 25 via the bus. When the user refers to information on the display 25 and the image information is unnecessary, the user can operate the operation switch 24 to delete the corresponding image information.

  Further, a zoom switch 23 is disposed on the rear surface, and the zoom motor drive circuit 26 can be controlled via the CPU 40 by operating the zoom switch 23, and the lens barrel 2 is moved in the optical axis direction of the lens. Let Further, the stored image displayed on the display 25 can be enlarged and reduced by so-called digital zoom by operating the zoom switch 23.

  Next, the lens barrel 2 of the present embodiment will be described in detail. FIG. 7 is a schematic sectional view showing a state in which the zoom lens 3 is at the wide end when the lens barrel 2 of the present embodiment is extended, and FIG. 8 is a state in which the zoom lens 3 is at the tele end when the lens barrel 2 is extended. 9 is a sectional view showing a state in which the lens barrel 2 is housed, FIG. 10 is an external perspective view showing a state in which the zoom lens 3 is at the wide end when the lens barrel 2 is extended, and FIG. FIG. 12 is an external perspective view showing the lens barrel 2 when it is housed, and FIG. 12 is an exploded perspective view of the lens barrel 2.

  The first lens 1 is held by the first lens holding member 2A, and the angle of view of the imaging device 15 is changed by moving the second lens holding member 4 holding the second lens (zoom lens) 3 in the optical axis direction. The second lens 3 moves forward (see FIG. 7) in a so-called TELE (tele) state that expands a narrow range, and the second lens 3 in a wide range, so-called WIDE (wide) state. 3 moves backward (see FIG. 8). The first to third lenses can also employ a lens group composed of one or more lenses, and the lens structure can be arbitrarily set in consideration of the performance and characteristics of the imaging device 15 and optical equipment. It is.

  As shown in FIG. 12, the inner surface of the zoom cam ring 5 is provided with a first cam groove 5d and a second cam groove 5e for operating the first lens holding member 2A and the second lens holding member 4, The first cam follower (first engaging portion) 2b formed on the one lens holding member 2A is in the first cam groove portion 5d, and the second cam follower 4a formed on the second lens holding member 4 is in the second cam groove portion 5e. Based on the drive signal from the zoom motor drive circuit 26, the zoom gear 5c provided integrally with the zoom cam ring 5 operates, the zoom cam ring 5 rotates, and the first lens holding member 2A and the first lens holding member 2A are rotated. 2 The lens holding member 4 moves.

  The zoom cam ring (second member) 5 is held at the outer periphery by a zoom cam ring holding member (first member) 6, and includes a seal portion 50 and a cam formed on the zoom cam ring holding member 6 inside the seal portion 50. An engagement portion 5f that engages with the groove portion 60 is formed. Due to the engagement between the cam groove portion 60 and the engagement portion 5f, movement of the zoom cam ring 5 in the optical axis direction with respect to the zoom cam ring holding member 6 is prevented. .

  Further, the zoom cam ring holding member 6 engages with a second engaging portion 2c provided on the first lens holding member (third member) 2A, so that the first lens holding member 2A (contact portion) is engaged. 2a) is provided with a rectilinear guide portion 6a for preventing rotation around the optical axis and guiding movement in the optical axis direction. The first lens holding member 2A is provided with a rectilinear guide portion 2d that prevents rotation of the second cam follower 4a of the second lens holding member 4 around the optical axis. A third cam follower 4b provided on the second lens holding member 4 is engaged with the rectilinear guide portion 2d to prevent the second lens holding member 4 from rotating about the optical axis.

  The zoom cam ring holding member 6 is attached to an image sensor holding member 9 that holds a CCD 10 as an image sensor. At the time of shooting, the third lens holding member 8 that holds the third lens 7 (focus lens) is driven in the optical axis direction by the motor via the focus motor drive circuit 28 to detect the focus of the subject image.

  The outer peripheral surface of the first lens holding member 2A is in contact with the first object-side end surface 5a of the zoom cam ring 5 and the second object-side end surface 5b formed on the image plane side with respect to the end surface 5a. A portion 2a is provided. The contact portion 2a is formed integrally with the second engagement portion 2c and in a substantially rectangular shape, and is longer in the circumferential direction than the second engagement portion 2c. The contact portion 2a is provided on the inner peripheral side of the second engagement portion 2c, and is provided in a second radial range B including the first radial range A in which the first cam follower 2b is provided. ing.

  As shown in FIGS. 7 and 10, when the lens barrel 2 is in the extended state, the contact portion 2a of the first lens holding member 2A and the end surface 5a of the zoom cam ring 5 are positioned in parallel to each other, and the contact portion 2a When the longitudinal direction is in contact with the end surface 5a and the lens barrel 2 is in the retracted state, as shown in FIGS. 9 and 11, the contact portion 2a and the end surface 5b of the zoom cam ring 5 are positioned in parallel to each other, and the contact portion 2a is in contact with the end face 5b.

  Next, the operation of the imaging device 15 having the optical apparatus of the present embodiment will be described with reference to FIGS.

  First, when the power of the photographing device 15 is turned on (S101), the CPU 40 outputs a drive signal to the zoom motor drive circuit 26, and a motor drive process is performed by the zoom motor drive circuit 26 (S102). Rotate in the CW direction. By the operation of the zoom motor driving circuit 26, the first lens holding member 2A and the second lens holding member 4 are moved forward in the optical axis, and the field angle is stopped in the WIDE state (S103).

  Thereafter, when the release switch 11 is turned on (SW1 is turned on) (S104), photometry and focus detection processing are performed for the focusing operation. The detected focus detection result is input to the CPU 40, and the CPU 40 outputs a drive signal to the focus motor drive circuit. The focus motor drive circuit 28 drives the motor to move the third lens holding member 8 (S105), and stops the movement of the third lens holding member 8 at the in-focus position at which the in-focus state is achieved (S106).

  Further, when the release switch 11 is turned on (SW2 is turned on) (S107), the shutter 30 is operated to take in the electric charge accumulated in the image pickup device 10 and perform digital image processing, expansion / compression processing, etc. Is stored in the memory 34 or the external storage device (S108, S109).

  When shooting is completed, the motor is driven via the focus motor drive circuit 28 to move the third lens holding member 8 in the retracted (closest end) direction and stop at the initial position (S110).

  Thereafter, when the user turns off the power of the photographing device 15 (S201), the motor is rotated in the CCW direction via the focus motor drive circuit 26, and the third lens holding member 8 is moved rearward of the optical axis (S202). . When the third lens holding member 8 reaches the reference position, the motor drive is stopped and the movement of the third lens holding member 8 is stopped (S203). Then, the motor is driven via the zoom motor drive circuit 28, and the first lens holding member 2A and the second lens holding member 4 are moved. In conjunction with the storing operation of the lens barrel 2, the barrier 18 moves in the closing direction so as to cover the front surface of the lens barrel 2, and the end processing is completed (S204).

  As described above, in this embodiment, the first diameter of the first cam follower 2b is provided on the inner peripheral side of the second engaging portion 2c that engages with the rectilinear guide portion 6a of the zoom cam ring holding member 6. Since the contact portion 2 a is provided in the second radial direction range B including the direction range A, the end surfaces 5 a and 5 b of the zoom cam ring 5 are brought into contact with the contact portion 2 a within the thickness range of the zoom cam ring 5. Can do.

  Therefore, the space between the members formed by providing the ribs as in the conventional example is not formed, that is, it is not necessary to provide the ribs on the zoom cam ring holding member 6 and the first lens holding member 2A. Since the first cam follower 2b and the contact portion 2a are disposed on substantially the same diameter within the thickness range of the zoom cam ring 5 to be disposed, the strength against impact is improved. It is possible to reduce the size of the lens barrel 2 in the radial direction.

  Further, since the second engaging portion 2c and the abutting portion 2a that engage with the rectilinear guide portion 6a are formed in substantially the same angular direction and are integrally formed, the shape of the zoom cam ring 5 is minimized. Can be suppressed.

  It should be noted that the radial range B of the abutting portion 2a, that is, the height in the radial direction, is brought into contact with the first and second object side end faces 5a and 5b of the zoom cam ring 5 within the thickness range of the zoom cam ring 5. If it is a range that includes the first radial range A that is the depth (the height in the radial direction) of the first guide groove portion 5d, it is in contact with the end surfaces 5a and 5b, and against the impact. Thus, the lens barrel 2 can be protected. For example, if the thickness of the zoom cam ring 5 is C, the first radial direction range A <the second radial direction range B (the height in the radial direction of the contact portion 2a) <the range of the thickness C of the zoom cam ring 5 Become.

  Then, in the extended state (first state) where the first lens holding member 2A is at the end position on the object side, the zoom cam ring 5 as the second member rotates in the first rotation region, thereby holding the second lens. When the member 4 moves and zooming is performed, and the zoom cam ring 5 rotates in a second rotation region different from the first rotation region, the first lens holding member 2A is moved to the object side end position. The zoom cam ring 5 moves in the optical axis direction with respect to the end position on the image plane side. The zoom cam ring 5 has a first object side end surface 5a that contacts the contact portion 2a in the extended state, and a first lens holding member 2A. And a second object-side end surface 5b that comes into contact with the contact portion 2a in the storage state (second state) at the side end position.

  That is, when the abutting portion 2a of the first lens holding member 2A and the end surface 5a are positioned in parallel at the time of extension and an external pressure such as an impact acts on the lens barrel 2, the longitudinal direction of the abutting portion 2a Since the abutting portion 2a and the end surface 5b abut when the end surface 5a abuts and an external pressure such as an impact is applied even when the lens barrel 2 is stored, the strength against the impact is improved.

  Therefore, it is possible to reliably prevent the first cam follower 2b from being detached from the cam and to protect the lens barrel 2.

  Note that the cam groove portion such as the first cam groove portion 5d of the present embodiment may be a ridge portion that engages a concave engaging portion with a convex cam portion, for example, and the function as a cam can be secured. Any other shape may be used as long as it has a shape.

FIG. 2 is an external perspective view illustrating a state in which a lens barrel (optical device) is extended in the imaging apparatus according to the first embodiment of the present invention. 1 is an external perspective view showing a state in which a lens barrel (optical device) is housed in an imaging apparatus according to Embodiment 1 of the present invention. FIG. 2 is a top view of FIG. 1. FIG. 3 is a bottom view of FIG. 2. It is a rear view of FIG. 1 is a block diagram illustrating a configuration of an imaging apparatus including an optical apparatus according to a first embodiment of the present invention. It is sectional drawing of the optical apparatus of Example 1 of this invention (WIDE state). It is sectional drawing of the optical apparatus of Example 1 of this invention (telephoto state). It is sectional drawing of the optical apparatus of Example 1 of this invention (at the time of accommodation). It is a composition perspective view of the optical equipment of Example 1 of the present invention. It is a composition perspective view of the optical equipment of Example 1 of the present invention. It is a disassembled perspective view of the optical apparatus of Example 1 of this invention. It is an operation | movement flowchart of the imaging device carrying the optical apparatus of Example 1 of this invention. It is an operation | movement flowchart of the imaging device carrying the optical apparatus of Example 1 of this invention.

Explanation of symbols

2a Contact part 2b 1st cam follower (1st engaging part)
2c Second engaging portion 2A Lens holding member (third member)
5 Zoom cam ring (second member)
5a End surface 5d Cam groove (first cam)
6 Zoom cam ring holding member (first member)
6a Guide part

Claims (5)

A first member;
A second member disposed on the inner peripheral side of the first member so as to be rotatable around the optical axis with respect to the first member, and provided with a first cam portion on the inner peripheral surface;
A first engagement portion that engages with the first cam portion on an outer peripheral surface, and a third member that is driven in the optical axis direction by rotation of the second member;
The first member has a guide portion that guides the third member in the optical axis direction,
The third member is provided with a second engagement portion that engages with the guide portion,
Furthermore, the outer peripheral surface of the third member is provided with a contact portion that contacts the object side end surface of the second member,
The abutting portion is provided on the inner peripheral side of the second engaging portion and in a second radial range including the first radial range in which the first engaging portion is provided. An optical device characterized by that.   The optical apparatus according to claim 1, wherein a length of the contact portion in a circumferential direction is longer than that of the engagement portion.   The optical apparatus according to claim 1, wherein the engagement portion and the contact portion are integrally formed.   The optical apparatus according to claim 1, wherein the second member is prevented from moving in the optical axis direction with respect to the first member. In the first state in which the third member is at the end position on the object side, the second member rotates in the first rotation region, and zooming is performed, and the second member is in the first state. The third member moves in the optical axis direction between the object-side end position and the image-side end position by rotating in a second rotation area different from the rotation area of
The second member includes the first object-side end surface that contacts the contact portion in the first state, and the second member in the second state where the third member is at the end position on the image plane side. 5. The optical apparatus according to claim 1, further comprising a second object-side end surface that contacts the contact portion.

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