JP2009216880A - Lens holding structure and photographing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens holding structure capable of preventing a cam follower from falling down from a cam groove due to impact, and making a camera thin in thickness. <P>SOLUTION: A lens barrel 100 has a cylindrical lens hold member 5 disposed in a movable cam ring 3 and holding a vibration-proof lens L5. A plurality of projections 5c projecting in the direction of an optical axis are formed on the peripheral part of the lens hold member 5. The projections 5c are disposed at predetermined intervals. Each of the projections 5c has at its leading end the cam followers 5a and 5b that engage with the cam groove 3c (not shown) of the movable cam ring 3. Deflection of each projection 5c in a direction perpendicular to the optical axis is restricted by the step 15a of a deflection restricting plate 15. This restricts deflection of the cam followers 5a and 5b in the direction perpendicular to the optical axis. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lens holding structure for holding a lens and a photographing apparatus having the lens holding structure.

  There are imaging devices such as film cameras that use silver salt film and digital cameras that use memory as recording media. In addition, there are zooms that change the shooting magnification by moving multiple optical lenses in the optical axis direction. Some are equipped with lenses.

  This zoom lens includes a plurality of lens holding members that respectively hold optical lenses. Among the lens holding members, the corresponding lens holding member is moved in the optical axis direction by the cam ring, and the rotation at the time of the movement is restricted by the straight advance restriction cylinder. With this configuration, the corresponding lens holding member, that is, the optical lens can be moved straight to a designated position.

  In recent years, there has been an increasing demand for higher magnifications of zoom lenses, and accordingly, the number of lens groups increases, and the total length (or extension length) of the lens barrel tends to increase. In addition, there is a strong demand for a thin camera, and there is a demand for making the camera as thin as possible when the lens barrel is housed.

  In order to reduce the thickness of the camera, a configuration in which the lens holding members for holding the lenses are shortened in the optical axis direction and the lens holding members are arranged in multiple stages and connected can be considered.

  In such a configuration, in order to drive each lens holding member in the optical axis direction, the locus that the cam follower follows the cam groove is appropriately connected, and the lens holding members are arranged so that the respective lenses do not interfere with each other. There is a need to. This may limit the arrangement of the lens holding members.

In addition, in the zoom lens, in order to prevent the cam follower from dropping off from the cam groove due to an impact, the cam follower that follows the cam groove is arranged at a thick part on the back side thereof so as not to bend ( Patent Document 1).
JP 2001-324663 A

  In the case of the above-described configuration in which the cam follower is disposed at a thick portion, the position of the cam follower provided in the lens holding member in the optical axis direction is restricted, which becomes an obstacle to the arrangement of the lens holding member. As a result, it is difficult to arrange the optimal cam groove for thinning the camera, and it is difficult to realize thinning of the camera.

  An object of the present invention is to provide a lens holding structure that can prevent a cam follower from dropping from a cam groove due to an impact and can reduce the thickness of a camera, and an imaging apparatus having the lens holding structure. .

  In order to achieve the above object, the present invention provides a cylindrical lens holding member that is disposed in a cam cylinder having an inner circumferential surface formed with a cam groove and holds an optical lens, and an outer peripheral portion of the lens holding member. A plurality of cam followers that are provided at predetermined intervals and engage with the cam grooves of the lens holding member, and a bending restriction for restricting the plurality of cam followers from bending in a direction perpendicular to the optical axis direction. A plurality of projecting portions projecting from the outer peripheral portion of the lens holding member in the optical axis direction, and the plurality of cam followers are respectively corresponding to the lens holding members. The lens holding structure, wherein the lens holding member is provided on a protrusion, and the bending restricting member restricts the plurality of protrusions of the lens holding member from bending in a direction perpendicular to the optical axis direction. To provide.

  In order to achieve the above object, the present invention provides a photographing apparatus including the lens holding structure.

  According to the present invention, it is possible to prevent the cam follower from dropping from the cam groove due to an impact, and it is possible to reduce the thickness of the camera.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view of a digital camera having a lens holding structure according to an embodiment of the present invention as viewed from the front side. FIG. 2 is a perspective view showing a state in which the lens barrel 100 of the digital camera of FIG. 1 is extended.

  The digital camera (imaging device) includes a camera body 17 as shown in FIG. A finder 22, auxiliary light source 21, strobe 23, and lens barrel 100 are arranged on the front surface of the camera body 17. A release button (shutter button) 18, a zoom button 19, and a power button 20 are disposed on the upper surface of the camera body 17.

  The lens barrel 100 is of a retractable type that is housed in the camera body 17 when not photographing. At the time of shooting, as shown in FIG. 2, the lens barrel 100 is extended outward from the camera body 17 and stopped at the shooting enabled position. The lens barrel 100 has a zoom mechanism for optically changing the photographing magnification, and the zoom mechanism moves the corresponding optical lens to a position corresponding to the magnification designated by the operation of the zoom button 19. .

  Next, the configuration of the lens barrel 100 will be described with reference to FIGS. FIG. 3 is an exploded perspective view of the lens barrel 100. FIG. 4 is a cross-sectional view of the lens barrel 100 in the retracted state. FIG. 5 is a cross-sectional view of the lens barrel 100 when it is in a shootable state (the extended state).

  As shown in FIG. 3, the lens barrel 100 includes a plurality of lens holding members 1, 2, 5, a plurality of movable cam rings 3, 8, a rectilinear regulation cylinder 4, a rectilinear regulation member 6, and a guide cylinder 7. The lens barrel 100 includes a fixed cam ring 9, a drive ring 10, and a fixed cylinder 11, as shown in FIGS.

  The lens holding member 1 is formed of a cylindrical member that holds the optical lens L1, and the lens holding member 1 is provided with a plurality of pin-shaped cam followers 1a (see FIG. 5). The lens holding member 2 includes a cylindrical member that holds the optical lens L2, and the lens holding member 2 is provided with three pin-shaped cam followers 2a (see FIG. 5). The cam followers 2 a are arranged along the outer periphery of the lens holding member 2 at an angular interval of 2π / 3 (rad). The lens holding member 5 is formed of a cylindrical member that holds the vibration-proof lens L5. The lens holding member 5 is integrally formed with a plurality of cam followers 5a and 5b (see FIGS. 5 and 6).

  The movable cam ring 3 is formed of a cylindrical member, and a plurality of (three) cam grooves 3a that engage with the cam follower 1a are formed on the outer peripheral surface thereof. A plurality of (three) cam grooves 3 b (not shown) that engage with the cam follower 2 a are formed on the inner peripheral surface of the movable cam ring 3. A cam groove 3 c (not shown) that engages with the cam followers 5 a and 5 b of the lens holding member 5 is formed on the inner peripheral surface of the movable cam ring 3.

  The rectilinear regulation cylinder 4 is disposed in the movable cam ring 3, and the movable cam ring 3 rotates along the outer periphery of the rectilinear regulation cylinder 4. Here, the rectilinear regulation cylinder 4 is guided by the rectilinear regulation part 6 a provided in the rectilinear regulation member 6 so as to linearly move in the optical axis direction. Further, the holding member 1 is restricted by the straight movement restricting cylinder 4 so as to move straight in the optical axis direction. Further, the lens holding members 2 and 5 are restricted by the straight advance restriction cylinder 4 so as to move straight in the optical axis direction. In other words, the lens holding members 1, 2, 5 move straight in the optical axis direction while being guided by the straight travel restriction member 6.

  As shown in FIGS. 4 and 5, the guide tube 7 is disposed on the outer periphery of the lens holding member 1. The guide tube 7 is bayonet-coupled to the movable cam ring 3 and is configured so as to be able to move back and forth along the optical axis direction substantially integrally with the movable cam ring 3. The guide cylinder 7 is provided with a cam follower 7 a, and the cam follower 7 a is engaged with a cam groove 8 a (not shown) provided in the movable cam ring 8. Thereby, the cam follower 7a follows the cam groove 8a, and the guide tube 7 and the movable cam ring 3 move substantially back and forth in the optical axis direction. Further, the guide cylinder 7 is fitted into a rectilinear restricting portion 6b provided in the rectilinear restricting member 6, thereby being guided so as to linearly move in the optical axis direction (see FIG. 3).

  The moving cam ring 8 is configured to be movable in the optical axis direction along a cam groove 9 a (not shown) provided in the fixed cam ring 9. The movable cam ring 8 receives a rotational force directly from the drive ring 10 disposed on the outer periphery of the fixed cam ring 9 and moves in the optical axis direction along the cam groove 9a (not shown) of the fixed cam ring 9. To do. The drive ring 10 is held by a fixed cylinder 11.

  Next, details of the lens holding member 5 of the present embodiment will be described with reference to FIGS. FIG. 6 is a front view showing details of the lens holding member 5 of FIG. FIG. 7 is a longitudinal sectional view of the lens holding member 5 of FIG. FIG. 8 is a longitudinal sectional view showing a state in which the lens holding member 5 of FIG. 6 is incorporated in the movable cam ring 3. FIG. 9 is a front view showing the deflection restriction 15 of FIG.

  As shown in FIG. 6, the lens holding member 5 holds an anti-vibration lens L <b> 5 that can move in a direction that cancels camera shake of the photographer. The lens holding member 5 accommodates a shutter drive unit 13 and an aperture drive unit 14, and the shutter drive unit 13 and the aperture drive unit 14 are positioned above the vibration-proof lens L5 and almost from the optical axis thereof. They are located at the same distance. Two anti-vibration lens driving units 16 are disposed below the anti-vibration lens L5.

  The lens holding member 5 is provided with two cam followers 5a and cam followers 5b. The lens holding member 5 is provided in the movable cam ring 3 (not shown) so that the cam followers 5a and 5b engage with cam grooves 3c (not shown) formed on the inner peripheral surface of the movable cam ring 3 (cam cylinder). In the cam cylinder). Thereby, the lens holding member 5 moves straight in the optical axis direction in conjunction with the movement of the movable cam ring 3.

  The cam followers 5a and 5b are arranged at a predetermined angular interval (for example, an angular interval of 2π / 3 (rad)) along the outer periphery of the lens holding member 5. The cam followers 5a and 5b are positioned on the outer peripheral side of the shutter driving unit 13, the diaphragm driving unit 14, and the vibration proof lens driving unit 16, and are positioned in front of the rear end in the optical axis direction of the vibration proof lens L5. (See FIG. 7 for details). At this time, the cam follower 5 b is disposed so as to be positioned between the two vibration-proof lens driving units 16.

  In this manner, by arranging the three cam followers 5a and 5b at predetermined angular intervals, a large installation space for the drive units 13, 14, and 16 can be secured.

  Regarding the cam followers 5a and 5b, as shown in FIG. 7, the cam follower 5b is formed at the tip of a protruding portion 5c protruding forward from the outer peripheral portion of the lens holding member 5 in the optical axis direction. Although not shown, the cam follower 5a is formed in the same manner. Due to such a structure, when an external impact or the like is applied, the protruding portion 5c is easily bent toward the image stabilizing lens L5 in a direction orthogonal to the optical axis direction. That is, each cam follower 5a, 5b is easily bent toward the image stabilizing lens L5 side. As a result, when an external impact or the like is applied, the cam followers 5a and 5b are disengaged from the cam groove 3c (not shown) of the moving cam ring 3, and the cam followers 5a and 5b are disengaged from the cam groove 3c of the moving cam ring 3. The possibility of dropping off increases.

  Therefore, in the present embodiment, as shown in FIGS. 8 and 9, a deflection regulating plate 15 (a deflection regulating member) is provided for regulating the deflection of the protruding portion 5c formed with each of the cam followers 5a and 5b. It has been. The bending restricting plate 15 is formed with a plurality of concave step portions 15a, and each step portion 15a is disposed at a position for receiving a corresponding protrusion 5c (cam follower 5a, 5b).

  Each step portion 15a has such a depth that when the corresponding protruding portion 5c is bent by a predetermined bending amount, the protruding portion 5c comes into contact with the bottom portion of the step portion 15a. The predetermined amount of bending is the amount of bending within the elastic deformation range of each protrusion 5c and the range in which the cam followers 5a and 5b do not fall off the cam groove 3c of the moving cam ring 3. Thereby, when each protrusion 5c bends, the amount of bend is restricted within a range in which the cam followers 5a and 5b do not fall out of the cam groove 3c of the movable cam ring 3.

  Further, the deflection regulating plate 15 also serves as a member for fixing the driving units 13, 14, and 16 to the lens holding member 5, and it is possible to reduce extra parts.

  Thus, by arranging the cam followers 5a and 5b at the front position in the optical axis direction of the vibration-proof lens L5, it is possible to arrange the cam groove 3c optimal for zoom driving in the movable cam ring 3. Further, since the cam followers 5a and 5b are disposed at the front position in the optical axis direction, as shown in FIG. 5, the lens holding member 5 can be moved further backward with respect to the movable cam ring 3. Finally, the length of the moving cam ring 3 in the optical axis direction can be further shortened.

  In the present embodiment, the lens holding member 5 that holds the vibration-proof lens L5 is provided with a plurality of protrusions 5c that protrude forward in the optical axis direction, and cam followers 5a and 5c are provided in each of the protrusions 5c. Yes. Accordingly, the cam followers 5a and 5b are disposed in front of the anti-vibration lens L5 in the optical axis direction. Instead, the lens holding member 5 is provided with a plurality of protrusions that protrude rearward in the optical axis direction, and each of the protrusions is provided with a cam follower. You may make it arrange | position at the back of an axial direction. In this case, the same effect can be obtained.

  Next, the internal configuration of the digital camera of this embodiment will be described with reference to FIG. FIG. 10 is a block diagram showing the internal configuration of the digital camera of FIG.

  As shown in FIG. 10, the digital camera has a control unit 50, and the control unit 50 includes a CPU, a ROM, a RAM, and the like. A plurality of operation buttons such as a release button 18, an operation button group 26, a zoom button 19, and a power button 20 are connected to the control unit 50 via a bus 47. The control unit 50 controls the display 25, the memory 43, the compression / decompression circuit 44, the memory card drive 45, and the drive circuit 46 via the bus 47 based on signals according to the operations of the operation buttons 18 to 20 and 26. Control.

  The drive circuit 46 drives the anti-vibration lens drive unit 16, the zoom motor drive unit 34, the focus motor drive unit 36, the shutter drive unit 13, and the aperture drive unit 14 based on a control signal from the control unit 50, respectively. A drive signal is generated. The drive circuit 46 generates drive signals for driving the image pickup device 40 and the strobe 23 made of CCD, CMOS, or the like.

  The anti-vibration lens driving unit 16 drives the anti-vibration lens L5 in a direction to correct image blur due to camera shake or the like. The zoom motor drive unit 34 drives the motor M1 to move the corresponding optical lens (lens holding member) of the lens barrel 100 so that the zoom magnification specified by the operation of the zoom button 19 is obtained. The focus motor driving unit 36 drives the motor M2 to move the corresponding optical lens (lens holding member) of the lens barrel 100 so that the focal position of the lens barrel 100 reaches the in-focus position. The shutter driving unit 13 drives the shutter 37. The diaphragm drive unit 14 drives the diaphragm 38.

  The image sensor 40 photoelectrically converts the subject image captured by the lens barrel 100 and outputs the electrical signal as an image signal. The image signal output from the image sensor 40 is subjected to predetermined processing in the analog signal processing unit 39 and then converted into a digital signal by the A / D conversion unit 41. The digital signal is output as image data, and the image data is subjected to predetermined processing in the digital signal processing unit 42 and then stored in the memory 43.

  The image data stored in the memory 43 is compressed by the compression / decompression unit 44 according to a predetermined format such as JPEG or TIFF, and then stored in the memory card 48 via the memory card drive 45.

  Further, the image data stored in the memory 43 or the image data stored in the memory card 48 can be expanded by the compression / decompression unit 44, and the expanded image data can be displayed on the display 25 via the bus 47. Further, the image data stored in the memory 43 or the image data stored in the memory card 48 can be erased by operating the corresponding operation button in the operation button group 26.

It is the perspective view which looked at the digital camera which has the lens holding structure which concerns on one embodiment of this invention from the front side. It is a perspective view which shows the state by which the lens-barrel 100 of the digital camera of FIG. 1 was extended. 2 is an exploded perspective view of a lens barrel 100. FIG. It is sectional drawing of the lens-barrel 100 in the state of accommodation. It is sectional drawing of the lens-barrel 100 in a case where it can image | photograph. It is a front view which shows the detail of the lens holding member 5 of FIG. It is a longitudinal cross-sectional view of the lens holding member 5 of FIG. It is a longitudinal cross-sectional view which shows the state in which the lens holding member 5 of FIG. It is a front view which shows the bending control board 15 of FIG. It is a block diagram which shows the internal structure of the digital camera of FIG.

Explanation of symbols

3 Moving cam ring (cam cylinder)
DESCRIPTION OF SYMBOLS 5 Lens holding member 5a, 5b Cam follower 5c Cam follower rear end 13 Shutter drive part 14 Aperture drive part 15 Deflection control board (deflection restriction member)
15a Step 16 Anti-vibration lens driving unit 37 Shutter 38 Aperture L5 Anti-vibration lens (optical lens)

Claims (8)

A cylindrical lens holding member that is disposed in a cam cylinder having a cam groove formed on the inner peripheral surface and holds an optical lens;
A plurality of cam followers provided at predetermined intervals on the outer periphery of the lens holding member and engaged with the cam grooves of the lens holding member;
A bending restriction member for restricting the plurality of cam followers from bending in a direction perpendicular to the optical axis direction,
The lens holding member is formed with a plurality of protrusions protruding in the optical axis direction from the outer periphery of the lens holding member,
Each of the plurality of cam followers is provided at a protrusion of the corresponding lens holding member,
The bend restricting member restricts the plurality of projecting portions of the lens retaining member from being deflected in a direction orthogonal to the optical axis direction.   The bending restricting member has a portion that comes into contact with each of the protruding portions when the plurality of protruding portions of the lens holding member are bent in a direction perpendicular to the optical axis direction by a predetermined bending amount. The lens holding structure according to claim 1.   3. The lens holding according to claim 2, wherein the predetermined bending amount is a bending amount within an elastic deformation range of the protruding portion and within a range in which the cam follower does not fall off from the cam groove of the cam cylinder. Construction.   2. The lens holding structure according to claim 1, wherein the plurality of protruding portions of the lens holding member protrude forward or rearward in the optical axis direction from an outer peripheral portion of the lens holding member. The lens holding member holds at least one driving unit that drives a mechanism for photographing, and the driving unit is disposed between the optical lens and the cam follower,
The lens holding structure according to claim 1, wherein the bending restricting member also serves as a holding member for holding the driving unit on the lens holding member.   The lens holding structure according to claim 1, wherein the driving unit is at least one of a shutter driving unit that drives a shutter and a driving unit that drives a diaphragm.   6. The optical lens held by the lens holding member is an anti-vibration lens, and the driving unit is a driving unit for driving the anti-vibration lens. The lens holding structure according to claim 1.   An imaging apparatus comprising the lens holding structure according to claim 1.

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