JP2011017769A - Optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device capable of providing a mechanism of shifting a follower which engages with a cam groove toward one side, even when the thickness in a radial direction of a lens holding frame cannot be fully secured.SOLUTION: A digital camera 100 includes: a first group lens barrel 11 which holds lenses; a ball follower 14, disposed to be radially movable with respect to the first group lens barrel 11; and a moving cam ring 21 having the cam groove with which the ball follower 14 engages. The digital camera 100 also includes a leaf spring 15 for energizing the ball follower 14 in the radial direction. Then, the digital camera 100 is configured to move the first group lens barrel 11 backwards and forwards, along a photographing optical axis accompanying the movement of the moving cam ring 21 in a predetermined direction. Additionally, in the digital camera 100, a fit-in part 11d which fits in and holds the ball follower 14, and a leaf spring storing part 11c for storing the leaf spring 15 are formed, at a position such that they overlap each other from the center of the optical axis of the first group lens barrel 11.

Description

  The present invention relates to an optical apparatus having a photographic lens.

  Conventionally, optical devices such as digital cameras having a zoom lens barrel have been widely used, and as a zoom feeding mechanism, a drive for moving the lens holding frame in the optical axis direction according to a cam groove provided in a known cam barrel is driven. The mechanism is known.

  The lens holding frame is planted with a follower pin that slidably engages with the cam groove, but there is always play between the cam groove and the follower pin in terms of component accuracy. It is conceivable that the eccentricity affects the optical performance. Therefore, measures have been taken to solve this problem.

  FIG. 13 is a view showing a follower pin play-off mechanism in a digital camera according to a conventional example (Patent Document 1).

  The follower pin 201 is held by a fitting hole 202a provided in the lens holding frame 202 so as to be slidable in the radial direction. Further, the lens holding frame 202 has a leaf spring storage portion 202d formed on the inner diameter side in communication with the fitting hole 202a. In the leaf spring storage portion 202d, a leaf spring 203 having substantially the same curvature as the inner diameter side surface 202e is disposed in a free state.

  When the follower pin 201 is incorporated in the cam cylinder 204, the rear end portion 201b presses the engaged portion 203a of the leaf spring 203 in the inner diameter direction. Then, both arm portions 203b of the leaf spring 203 come into contact with the inner diameter side surface 202e to deform the curvature of the leaf spring 203.

  As a result, the reaction force acts on the follower pin 201, and the follower pin 201 generates a force that tends to protrude in the outer diameter direction. As a result of this force, the tapered portion 201c of the follower pin is pressed and urged against the cam groove 204a of the cam barrel 204, so that the lens holding frame 202 can be supported without rattling.

JP-A-11-109209

  However, the above-described conventional example has the following problems.

  In FIG. 13, the leaf spring storage portion 202d for storing the leaf spring 203 communicates with the fitting hole 202a and is provided on the inner diameter side thereof, so that a radial thickness is required to provide the shifting mechanism. .

  Therefore, in the case where the thickness in the radial direction of the lens holding frame 202 cannot be taken, such as when another member is arranged on the inner diameter side of the lens holding frame 202, the leaf spring 203 cannot be arranged on the inner diameter side of the follower pin 201. There was a problem that it was not possible to provide a side-by-side mechanism. Alternatively, there has been a problem that the taking lens barrel is enlarged in the radial direction in order to provide a side-by-side mechanism.

  An object of the present invention is to provide an optical apparatus capable of providing a follower shifting mechanism that engages with a cam groove even when the radial thickness of the lens holding frame cannot be sufficiently obtained.

  In order to achieve the above object, an optical apparatus according to claim 1 includes a holding frame for holding an optical element, a ball follower provided to be movable in a radial direction with respect to the holding frame, and the ball follower. A cam member having a mating cam groove and an urging means for urging the ball follower in a radial direction, and the holding frame is moved forward and backward along the photographic optical axis as the cam member moves in a predetermined direction; In the optical apparatus, a guide portion that fits and holds the ball follower is formed in a storage portion that stores the urging means.

  The optical device according to claim 2, wherein the cam member includes a holding frame that holds an optical element, a ball follower that is movable in a radial direction with respect to the holding frame, and a cam groove that engages with the ball follower. And a urging means for urging the ball follower in the radial direction and a rectilinear member for regulating the rectilinear movement of the holding frame, and the holding frame is moved along the photographic optical axis as the cam member moves in a predetermined direction. In the optical device to be advanced and retracted, a guide portion for fitting and holding the ball follower and a storage portion for storing the urging means are formed at a position overlapping the optical axis center of the holding frame, A recess is provided in the thickness of the rectilinear restricting portion with which the holding frame engages with the rectilinear member, and an engaged portion with the ball follower formed in the urging means is disposed in the recess. And

  According to the optical apparatus of the present invention, a follower shifting mechanism that engages with the cam groove can be provided even when the lens holding frame is not sufficiently thick in the radial direction due to the above configuration.

It is an external appearance perspective view which shows the state which turned off the power supply of the digital camera 100 as an optical apparatus which concerns on embodiment of this invention. FIG. 2 is an external perspective view showing a state in which the digital camera 100 in FIG. 1 is turned on. FIG. 2 is a top view of the digital camera 100 in FIG. 1. It is a rear view of the digital camera 100 of FIG. FIG. 2 is a bottom view of the digital camera 100 of FIG. 1. It is a block block diagram of the digital camera 100 of FIG. It is sectional drawing of the SINK position of the photographic lens barrel 36 in FIG. It is sectional drawing of the WIDE position of the imaging lens barrel 36 in FIG. It is an external appearance perspective view of the 1st group lens barrel 11 in FIG. It is an optical axis orthogonal sectional view of a ball follower side shift mechanism part. It is a projection enlarged view (before a leaf | plate spring incorporation) around a leaf | plate spring storage part. It is a projection enlarged view (after leaf spring incorporation) around a leaf spring storage part. It is a figure which shows the backlash removal mechanism of the follower pin in the digital camera which concerns on a prior art example.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  A digital camera 100 as an optical apparatus described in this embodiment includes a zoom mechanism that can change a photographing magnification.

  FIG. 1 is an external perspective view showing a state in which a power source of a digital camera 100 as an optical apparatus according to an embodiment of the present invention is turned off. FIG. 2 is an external perspective view showing a state where the power source of the digital camera 100 of FIG. 1 is turned on. FIG. 3 is a top view of the digital camera 100 of FIG. 4 is a rear view of the digital camera 100 of FIG. FIG. 5 is a bottom view of the digital camera 100 of FIG. FIG. 6 is a block diagram of the digital camera 100 of FIG.

  Hereinafter, the configuration will be described together with the operation.

  In front of the digital camera 100, an auxiliary light emitting unit 33 for assisting a light source when performing photometric distance measurement, a finder 34 for determining the composition of the subject, a strobe 35, and a photographing lens barrel 36 are arranged.

  On the top surface of the digital camera 100, a release button 30, a zoom changeover switch 31, and a power supply changeover button 32 are arranged. On the bottom surface of the digital camera 100, a card battery cover 46 having a tripod mounting portion 45, a memory card drive 59, and a battery insertion portion (not shown) provided therein is disposed.

  Operation buttons 39, 40, 41, 42, 43, and 44 are arranged on the back of the digital camera 100, and various function switching can be performed. On the back of the digital camera 100, a display 38 made of LCD and a viewfinder eyepiece 37 are arranged.

  The operation buttons 39, 40, 41, 42, 43, and 44 are used to select an operation mode of the digital camera, such as a shooting mode, a playback mode, and a moving image shooting mode.

  The display 38 is image display means and displays the image data stored in the memory 57 and the image data read from the memory card on the screen. In addition, when a mode is selected, a plurality of shooting data can be reduced and displayed on the screen.

  The control unit includes a CPU 63, a ROM 62, and a RAM 64, and various components such as a release button 30, operation buttons 39 to 44, a display 38, a memory 57, and a memory card drive 59 are connected via a bus 61.

  The driving circuit 60 connected to the control system via the bus 61 includes a zoom motor driving unit 47, a focus motor driving unit 49, a shutter driving unit 51, an aperture driving unit 53, an imaging device 4 such as a CCD or CMOS, and a strobe 35. It is connected. Each drive is controlled by a signal from the control system. The ROM 62 stores a program for controlling each functional component described above. The RAM 64 stores data necessary for each control program.

  As described above, although the digital camera 100 is configured, when the user operates the power switch button 32 to turn on the power from off to on, the CPU 63 reads a necessary control program from the ROM 62 and performs an initial operation. Start. That is, the photographing lens barrel 36 is moved to a predetermined photographable area, the photographing function is activated, and the photographing standby state is set.

  When the release button 30 is pressed to take a picture, the brightness of the subject is detected by the imaging device 4, and the CPU 63 detects the aperture value of the aperture unit 52, the shutter speed of the shutter unit 50, based on the photometric value, It is determined whether or not the strobe 35 emits light. In addition, the user can select whether the strobe 35 is forced to emit light or not by using the operation button 40 in advance.

  Next, the CPU 63 measures the distance, measures the distance to the subject, and moves the focus unit 48 to a predetermined focus position by the focus motor drive unit 49. Next, the CPU 63 opens and closes the shutter unit 50 and captures a desired image into the imaging device 4.

  In the imaging device 4, charges corresponding to the amount of incident light are accumulated based on the exposure control value, and the charges become an image signal and are output to the analog signal processing unit 54. The analog signal processing unit 54 performs analog processing on the captured image data and outputs it to the A / D conversion unit 55.

  The A / D converter 55 converts the captured analog data into digital data. This digital data is output to the digital signal processing unit 56, where the digital data is processed. Finally, the digital data is stored in the memory 57.

  The data stored in the memory 57 is subjected to compression processing such as JPEG or TIFF by the compression / decompression unit 58 by the operation of the operation button 41, and is output and stored in the memory card. In the case of a digital camera that does not have the memory 57, the digital data processed by the digital signal processing unit 56 is output to the compression / decompression unit 58 and stored in the memory card drive 59.

  The image data stored in the memory 57 or the image data stored in the memory card drive 59 is expanded by the compression / decompression unit 58 and the image data is displayed on the display 38 via the bus 61. it can.

  If the user views the data on the display 38 and determines that the image is unnecessary, the user can delete the image by operating the operation button 42. By operating the zoom changeover switch 31 and controlling the zoom motor drive unit 47 via the drive circuit 60, the photographing lens barrel 36 is moved in the optical axis direction of the lens.

  Further, the stored image displayed on the display 38 can be enlarged or reduced by the operation of the zoom changeover switch 31, so-called digital zoom.

  Next, the configuration of the taking lens barrel 36 provided in the digital camera 100 will be described.

  The digital camera 100 includes a holding frame (first group barrel 11) that holds an optical element (lens), a follower (ball follower 14) that is movable in a radial direction with respect to the holding frame, and a follower. And a cam member (moving cam ring 21) having a mating cam groove. The digital camera 100 also includes a biasing means (plate spring 15) that biases the follower in the radial direction. The digital camera 100 is configured to advance and retract the holding frame along the imaging optical axis as the cam member moves in a predetermined direction.

  7 is a cross-sectional view of the photographic lens barrel 36 in FIG. 1 at the SINK position, and FIG. 8 is a cross-sectional view of the photographic lens barrel 36 in FIG. 1 at the WIDE position.

  7 and 8, the taking lens barrel 36 includes a first group lens 1 and a second group lens 2 having a zooming function, a third group lens 3 for controlling focus and image plane correction, and moving each group lens in the optical axis direction. A first group barrel 11, a second group barrel 12, and a third group barrel 13 are provided to be held.

  The first group barrel 11 and the second group barrel 12 are held by a movable cam ring 21 having a cam groove on the inner periphery. The fixed cylinder 22 holds the movable cam ring 21 movably by a cam groove provided on the inner periphery. A fixed cylinder 22 is fixed to a CCD holder 23 that holds an imaging device (CCD).

  The drive ring 24 rotates the moving cam ring 21. The rectilinear guide ring (straight member) 25 moves straight while suppressing the rotation of the first group barrel 11 and the second group barrel 12. The cover cylinder 26 is fixed to the CCD holder 23 and restricts the movement of the drive ring 24 in the optical axis direction.

  The operation of the taking lens barrel 36 configured as described above will be described in detail.

  The rotation of the zoom motor (not shown) is transmitted to the drive ring 24 via the outer peripheral gear 24a formed on the drive ring 24 by a gear system (not shown), and rotates the drive ring 24. The front end portion of the drive ring 24 is in contact with the flange portion 26a of the cover cylinder 26, and the rear end portion is in contact with a flange portion 22c provided at the rear end portion of the fixed cylinder 22, thereby driving The movement of the ring 24 in the optical axis direction is restricted. Three straight guide grooves (not shown) having a uniform width in the optical axis direction are provided on the inner peripheral side surface of the drive ring 24.

  Three followers (not shown) that fit into the three cam grooves 22 a of the fixed cylinder 22 are held on the outer periphery of the movable cam ring 21, and the movable cam ring 21 is cam grooves 22 a of the fixed cylinder 22 according to the rotation. Move along.

  A drive pin 21 a is planted substantially behind the follower, and passes through three guide grooves 22 b that are provided on the side surface of the fixed cylinder 22 and penetrate in the thickness direction. It is slidably fitted.

  When the drive ring 24 rotates, the rotation is transmitted to the movable cam ring 21 through the drive pin 21 a, and the movable cam ring 21 moves in the optical axis direction while rotating along the cam groove 22 a of the fixed cylinder 22.

  The linear guide ring 25 is restricted from moving relative to the movable cam ring 21 in the optical axis direction. The rectilinear guide ring 25 is fitted to a not-illustrated rectilinear guide provided on the inner peripheral side surface of the fixed cylinder 22 so that the rectilinear guide cylinder 25 is restricted from moving in the rotational direction. Yes.

  Therefore, when the movable cam ring 21 rotates and moves along the cam groove 22a of the fixed cylinder 22, the rectilinear guide ring 25 moves only in the optical axis direction following the movement of the movable cam ring 21 in the optical axis direction. The first group lens barrel 11 and the second group lens barrel 12 are held in the cam grooves 21c and 21d of the moving cam ring 21, respectively.

  Since each group barrel is restrained from rotational movement by the straight guide ring 25, when the movable cam ring 21 moves, each group barrel moves in the direction of the optical axis without rotating, and the desired focal point. It is possible to arrange lenses according to the distance.

  The first lens barrel 11 is provided with a known lens barrier 11a, which blocks the optical path of the photographing optical system in the retracted state. The second group barrel 12 is provided with a known shutter unit and camera shake correction mechanism, and moves in the optical axis direction integrally with the second group barrel 12.

  Next, the shifting mechanism of the ball follower 14 will be described in detail with reference to FIGS. 9, 10, 11, and 12.

  FIG. 9 is an external perspective view of the first group lens barrel 11 in FIG. 7, FIG. 10 is a cross-sectional view orthogonal to the optical axis of the ball follower shifting mechanism, and FIG. FIG. 12 is a projected enlarged view around the leaf spring storage (after the leaf spring is assembled).

  As shown in FIGS. 7 and 8, in the configuration of the taking lens barrel 36 of the present embodiment, since the straight guide ring 25 is disposed on the inner diameter side of the first group barrel 11, the first group barrel 11. The thickness of the can not be taken sufficiently. Among them, it is a feature of the present invention to provide a shifting mechanism that eliminates the backlash of the first group barrel 11.

  The first group barrel 11 is provided with a leaf spring storage portion 11c for holding the leaf spring 15 and a fitting portion 11d for holding the ball follower 14 engaged with the cam groove 21c so as to be slidable in the radial direction. It has been. The fitting portion 11d functions as a guide portion that fits and holds the ball follower 14. A fixing pin 16 is planted substantially behind the ball follower 14 to prevent the ball follower 14 from dropping from the cam groove 21c at the time of a drop impact.

  The leaf spring storage portion 11c is formed in the circumferential direction of the first group barrel 11, and has a recess in the thickness of the rectilinear key 11b fitted in the rectilinear guide groove 25a of the rectilinear guide ring 25 (FIG. 10). reference).

  Furthermore, as shown in FIG. 11 and FIG. 12, the leaf spring storage portion 11c sets the fitting portion (engaged portion) 11d by setting the width W of the leaf spring 15 to be smaller than the diameter D of the ball follower 14. It is realized to be provided integrally with the fitting portion 11d at a position that is notched and overlaps from the center of the optical axis.

  As shown in FIG. 11, the substantially central portion of the fitting portion 11d is cut out by the leaf spring storage portion 11c, but since the cylindrical side surface having the same curvature as the diameter D remains before and after that, the ball follower There is no hindrance to the fitting support.

  The leaf spring 15 is formed with a diameter substantially the same as the outer diameter of the first lens barrel so that when the ball follower 14 is incorporated into the cam groove 21c, the leaf spring 15 is accommodated in the leaf spring housing portion 11c. A ball follower urging portion 15a is provided so as to fit in the recess of 11c (see FIG. 10).

  When the ball follower 14 is incorporated in the cam groove 21c, the ball follower 14 presses the ball follower urging portion 15a of the leaf spring 15 in the inner diameter direction. As a result, a reaction force acts on the ball follower 14 to generate a force protruding in the outer diameter direction.

  With this force, the ball follower 14 is pressed and urged against the cam groove 21 c of the movable cam ring 21, and can absorb the play of the first group barrel 11. Of course, at this time, since the ball follower 14 is supported by the fitting portion 11d, movement other than the radial direction is restricted.

  As described above, in the present embodiment, even when the radial thickness of the first group lens barrel 11 cannot be sufficiently obtained, the thickness of the rectilinear restricting portion with the rectilinear guide ring 25 is effectively used to make the leaf spring 15 A ball follower urging portion 15a is provided. Thereby, it is possible to provide a biasing mechanism of the ball follower 14 that engages with the cam groove 21c.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

DESCRIPTION OF SYMBOLS 1 1st group lens 2 2nd group lens 3 3rd group lens 4 Imaging device 11 1st group barrel 12 2nd group barrel 13 3rd group barrel 14 Ball follower 15 Leaf spring 16 Fixed pin 21 Moving cam ring 22 Fixed barrel 23 CCD holder 24 Drive ring 25 Straight guide ring 26 Cover tube

Claims (3)

A holding frame for holding an optical element, a ball follower provided to be movable in the radial direction with respect to the holding frame, a cam member having a cam groove with which the ball follower is engaged, and the ball follower in the radial direction And an urging means for urging the optical device for moving the holding frame forward and backward along the photographing optical axis as the cam member moves in a predetermined direction.
An optical apparatus, wherein a guide portion that fits and holds the ball follower is formed in a storage portion that stores the biasing means. A holding frame for holding an optical element, a ball follower provided to be movable in the radial direction with respect to the holding frame, a cam member having a cam groove with which the ball follower is engaged, and the ball follower in the radial direction In an optical device that includes an urging unit that urges and a rectilinear member that regulates the rectilinear movement of the holding frame, and moves the holding frame forward and backward along the photographic optical axis as the cam member moves in a predetermined direction,
A guide portion for fitting and holding the ball follower and a storage portion for storing the urging means are formed at positions overlapping the optical axis center of the holding frame, and the holding frame is connected to the rectilinear member in the storage portion. An optical apparatus, wherein a concave portion is provided in a wall thickness of the linearly regulating portion to be engaged, and a portion to be engaged with the ball follower formed in the biasing means is disposed in the concave portion.   3. The optical apparatus according to claim 1, wherein the biasing means is a leaf spring, and the width thereof is set smaller than the diameter of the ball follower.