JP6576030B2 - Lens barrel assembly method - Google Patents

Description

  The present invention relates to a lens barrel of an imaging apparatus such as a digital camera.

  The imaging apparatus can perform zooming by moving the lens unit of the lens barrel in the optical axis direction using a zoom mechanism. For example, a cam cylinder provided with a cam groove is disposed on the outer periphery of a fixed cylinder provided with a straight advance groove, and the lens group is caused to follow the cam groove while being guided linearly in the straight advance groove. Accordingly, zooming can be performed by rotating the cam cylinder and moving the lens unit in the optical axis direction. Further, in order to drive a plurality of lens units, it is necessary to form a plurality of cam grooves corresponding to the plurality of lens units in the cam cylinder.

  In Patent Document 1, a cam groove introducing portion for incorporating the follower means of the lens unit into the cam groove is arranged so as not to interfere with other cam grooves, and the cam grooves are configured not to interfere with each other. A zoom lens barrel is disclosed. Patent Document 2 discloses a lens barrel in which a cam follower can be inserted into a lens holder from the outer periphery.

JP 2002-215042 A JP 2005-115169 A

  However, in the configuration of Patent Document 1, since the cam groove is largely detoured and the path of the cam groove is lengthened, the required surface area on the inner periphery of the cam cylinder increases, and it is necessary to use a large cam cylinder. In the configuration of Patent Document 2, after the lens holder is incorporated into the cam barrel, only the follower pin can be inserted into the lens holder through an opening formed on the side surface of the cam barrel. However, in this case, it is necessary to form an opening in the outer periphery of the cam cylinder, and it is necessary to incorporate a separate follower from the outside. For this reason, the number of parts increases and the assembly work becomes complicated.

Therefore, the present invention provides a method of assembling a lens barrel that can be easily assembled with a small and simple configuration.

The lens barrel assembling method according to one aspect of the present invention includes: a first cam groove on the inner periphery of the cylinder; and a position different from the first cam groove in the optical axis direction and at an end on one side. A cam cylinder in which a second cam groove is formed, a first cam pin that is disposed on an inner peripheral side of the cam cylinder and is inserted into the first cam groove, and the cam cylinder rotates to rotate the first cam pin. A lens barrel having a lens holding member having an elastic portion that holds the first cam pin that moves in one cam groove, wherein the second cam groove has an entire circumference of the cam barrel. When viewed from the radial direction of the cam cylinder, the introduction portions provided on both sides in the optical axis direction of the second cam groove with respect to the radial direction of the cam cylinder are less than the first cam groove. Also protrudes toward the inside of the cam cylinder, and the lens holding member is attached to the cam cylinder. When inserted, the first cam pin is inserted into the first cam groove over the introduction portion of the second cam groove by elastically deforming the elastic portion toward the inside of the cam cylinder in the radial direction. It is characterized by that.

  Other objects and features of the invention are described in the following embodiments.

ADVANTAGE OF THE INVENTION According to this invention, the assembly method of the lens barrel which can be assembled easily with a small and simple structure can be provided.

It is a perspective view of the 2nd lens holding means and cam cylinder of the lens barrel in this embodiment. It is sectional drawing of the accommodation state (at the time of power supply OFF) of the lens-barrel in this embodiment. It is sectional drawing of the operation state (at the time of power supply ON) of the lens-barrel in this embodiment. It is a perspective view of the 2nd lens holding means of the lens barrel in this embodiment. It is sectional drawing of the cam cylinder of the lens barrel in this embodiment. It is sectional drawing of the lens-barrel in this embodiment. It is sectional drawing of the lens-barrel in this embodiment. It is sectional drawing of the lens-barrel in this embodiment. It is sectional drawing of the lens-barrel in this embodiment. It is an external appearance perspective view of an imaging device provided with the lens barrel in this embodiment. It is a rear view of the imaging device in this embodiment. It is a block diagram of the imaging device in this embodiment.

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

  First, with reference to FIG. 7A, FIG. 7B, and FIG. 8, the imaging apparatus provided with the lens barrel in the present embodiment will be described. FIG. 7A is an external perspective view (front perspective view) of the imaging apparatus (digital camera 23). FIG. 7B is a rear view of the imaging apparatus. FIG. 8 is a block diagram of the imaging apparatus. The digital camera 23 of the present embodiment includes a zoom mechanism that moves the lens unit in the optical axis direction between the shooting position and the storage position to change the shooting magnification.

  As shown in FIG. 7a, on the front of the digital camera 23, a finder 21 for determining the composition of the subject, an auxiliary light source 20, a strobe 22, and a lens mirror used for photometry and distance measurement (focus detection) A cylinder 6 (lens barrel) is disposed. On the top surface of the digital camera 23, a release button 17, a zoom switch 18, and a power switch button 19 are arranged. As shown in FIG. 7 b, operation buttons 26 to 31, a display 25 (liquid crystal unit) such as an LCD, and a viewfinder eyepiece unit 24 are arranged on the back of the digital camera 23.

  The display 25 is an image display means for displaying the image data stored in the memory 38 and the image data read from the memory card on the screen. The control unit (control system) includes a CPU 44, a ROM 43, and a RAM 45. The control unit is connected to various components such as the release button 17, the operation buttons 26 to 31, the display 25, the memory 38, and the memory card drive 40 via the bus 42.

  The drive circuit 41 is connected to the control unit via the bus 42. The drive circuit 41 is connected to the zoom mechanism 32, the focus drive mechanism 16, the shutter drive mechanism 33, the aperture drive mechanism 34, the image sensor 15 such as a CCD or CMOS, and each part of the strobe 22. Each part is a control unit. It is controlled based on the signal from The zoom mechanism 32 drives the lens barrel 6 (lens barrel portion) via a motor. The focus drive mechanism 16 drives the focus lens 12 via a motor. The shutter drive mechanism 33 drives the shutter 7a. The aperture drive mechanism 34 drives the aperture 7b. The image sensor 15 photoelectrically converts an optical image (subject image) formed via the lens unit of the lens barrel 6 and outputs an image signal. With such a configuration, the drive circuit 41 controls driving of each unit based on a signal from the control unit (CPU 44).

  The ROM 43 stores various control programs for controlling the functions of the above-described units. The RAM 45 stores data necessary for various control programs. The analog signal processing unit 35 performs analog processing on the image data output from the image sensor 15 and outputs the analog data to the A / D conversion unit 36. The A / D conversion unit 36 converts analog data obtained from the image sensor 15 into digital data and outputs the digital data to the digital signal processing unit 37. The digital signal processing unit 37 performs a predetermined process on the digital data converted by the A / D conversion unit 36 and outputs it to the memory 38 as image data. The image data is stored in the memory 38.

  The image data stored in the memory 38 is subjected to compression processing such as JPEG or TIFF by the compression / decompression unit 39 according to the operation of the operation button 27. After the compression processing by the compression / decompression unit 39, the image data is output to and stored in a memory card attached to the memory card drive 40. The compression / decompression unit 39 performs decompression processing of image data stored in the memory 38 or image data stored in the memory card. The image data after the expansion process can be displayed on the display 25 (display unit) via the bus 42. When the user views the image displayed on the display 25 and determines that the image is unnecessary, the user can delete the image by operating the operation button 28.

  Next, the configuration of the lens barrel 6 provided in the digital camera 23 will be described with reference to FIGS. 1 to 3. FIG. 1 is a perspective view of the second lens holding means 2 and the cam barrel 3 of the lens barrel 6 in the present embodiment. FIG. 2A is a cross-sectional view of the lens barrel 6 in a stored state (when the power is off). FIG. 2B is a cross-sectional view of the lens barrel 6 in the manipulated state (when the power is turned on). FIG. 3 is a perspective view of the second lens holding means 2.

  2A and 2B, the lens barrel 6 includes a first lens unit 5, a second lens unit 1, a third lens unit 8, a fourth lens unit 10, and a focus lens 12 (focus lens unit). ). The first lens unit 5 is held by first lens holding means 61. Behind the first lens holding means 61 (image side), the second lens holding means 2 for holding the second lens unit 1 is disposed. Behind the second lens holding means 2 (image side), an aperture / shutter means 7 in which a shutter 7a (shutter unit) and an aperture 7b (aperture unit) are integrally formed is disposed. A third lens holding means 9 for holding the third lens unit 8 is disposed behind the aperture / shutter means 7 (image side). A fourth lens holding means 11 for holding the fourth lens unit 10 is arranged behind the third lens holding means 9 (image side). A focus lens holding unit 13 that holds the focus lens 12 is disposed behind (on the image side) the fourth lens holding unit 11.

  As shown in FIGS. 1, 2 a, and 2 b, the lens barrel 6 has a fixed barrel 4. A cam cylinder 3 is provided on the outer periphery of the fixed cylinder 4. Further, an image sensor holding unit 14 for holding the image sensor 15 is provided on the most back side (image side). The focus drive mechanism 16 (focus drive means) is fixed in front of the image sensor holding means 14 (object side). The motor which is the focus drive mechanism 16 is provided with a screw, and the focus lens holding means 13 is configured to follow the operation. With such a configuration, the focus lens 12 can move in the front-rear direction (optical axis direction) along the optical axis OA, and the entire imaging apparatus can be focused (focus adjustment is performed).

  A cam groove 3 a (second cam groove) is formed on the inner periphery of the cam cylinder 3. The cam groove 3a is configured such that follower means 4a provided on the fixed cylinder 4 abuts. A cam groove 3 f (first lens following cam groove) is formed on the outer periphery of the cam cylinder 3. The first lens holding means 61 is configured to follow the cam groove 3f. A cam groove 3 c (second lens following cam groove) is formed on the inner periphery of the cam cylinder 3. The follower means 2a provided in the second lens holding means 2 is configured to follow the cam groove 3c. A plurality of other cam grooves are formed on the inner periphery of the cam cylinder 3. The aperture / shutter unit 7, the third lens holding unit 9, and the fourth lens holding unit 11 are configured to follow each of the plurality of cam grooves.

  The fixed cylinder 4 is provided with a straight travel restricting means 4b. The rectilinear regulation means 4b guides the second lens holding means 2 rectilinearly. A guide bar (not shown) is attached to the fixed cylinder 4, and the diaphragm / shutter means 7, the third lens holding means 9, and the fourth lens holding means 11 are guided in a straight line. Near the tip of the fixed cylinder 4 (near the most object side), a rectilinear regulating means 4d for guiding the first lens holding means 61 rectilinearly is provided. The straight movement restricting means 4d guides the first lens holding means 61 straight by fitting into the first straight movement groove 6a formed on the inner periphery of the first lens holding means 61 and performing restriction.

  As shown in FIG. 3, the second lens holding means 2 has three beam-shaped portions on the back surface (outer surface) thereof. A follower means 2a is provided at the tip of each of the three beam-shaped portions. Each of the three beam-shaped portions is an elastic means 2 b having an elastic force (elastically deformable) capable of bending in the radial direction (the direction perpendicular to the optical axis) of the second lens holding means 2. In this embodiment, the follower means 2a and the elastic means 2b are equally arranged in the circumferential direction (at intervals of about 120 degrees). However, in this embodiment, the number and arrangement interval of the follower means 2a (elastic means 2b) are not limited to this.

  Next, with reference to FIGS. 4 to 6b, the state when the second lens holding means 2 is incorporated into the cam barrel 3 will be described. FIG. 4 is a cross-sectional view of the cam cylinder 3. FIG. 5 a is a sectional view (side sectional view) of the lens barrel 6 and shows a state in which the second lens holding means 2 is incorporated into the cam barrel 3. The left side view of FIG. 5a is an enlarged view of a region A1 in the right side view. FIG. 5 b is a sectional view (side sectional view) of the lens barrel 6. 6a is a cross-sectional view (front cross-sectional view) of the lens barrel 6 and shows a cross-sectional view taken along line XX in FIG. 5a. The left side view of FIG. 6a is an enlarged view of a region A2 in the right side view. 6B is a cross-sectional view of the lens barrel 6. The left side view is a side cross-sectional view of the lens barrel 6. The right side view is an enlarged view of the front cross-sectional view in the range D1 in FIG. 5B.

  As shown in FIG. 5 a, the second lens holding means 2 is inserted from the front (object side) in a state where the cam cylinder 3 is integrated with the fixed cylinder 4. At this time, the phases of the cam introduction groove 3g on the extension of the cam groove 3c (first cam groove) formed on the inner periphery of the cam cylinder 3 and the straight advance restriction means 4b provided on the fixed cylinder 4 are changed. After matching, the follower means 2a of the second lens holding means 2 is inserted in accordance with the same phase. In this embodiment, the cam introduction groove 3g is a part of the cam groove 3c, and both the cam introduction groove 3g and the cam groove 3c may be collectively referred to as a cam groove 3c.

  As shown in FIGS. 4 and 5a, the follower means 4a provided in the fixed cylinder 4 is configured to abut on the front side (object side) of the cam introduction groove 3g formed in the cam cylinder 3. A cam groove 3a (second cam groove) is provided on the entire circumference of the cam cylinder 3 along the circumferential direction. In the present embodiment, the depth of the cam groove 3a (the direction orthogonal to the circumferential direction, that is, the depth of the cam groove 3a in the radial direction) is deeper than the depth of the cam introduction groove 3g. In the present embodiment, the cam introduction groove 3g does not extend to the front surface (the object side end) of the cam cylinder 3 and is blocked by the cam groove 3a (discontinuity at a position closer to the image side than the cam groove 3a). ing). The cam cylinder 3 is provided with a blocking rib 3b (blocking portion) along the cam groove 3a. Due to the presence of the blocking rib 3b, the cam groove 3c cannot extend to the outside of the cam cylinder 3 (the end on the object side, that is, the cam groove 3a). With this configuration, the cam groove 3a can be formed on the entire circumference of the cam cylinder 3 without being divided in the circumferential direction.

  As shown in FIG. 6b, when the second lens holding means 2 is incorporated into the cam barrel 3, the elastic means 2b provided on the second lens holding means 2 is in the direction indicated by the arrow (inner circumferential direction, ie, radial direction). ) Toward (elastically deform). Thereby, the follower means 2a provided on the elastic means 2b is displaced in the inner peripheral direction (radial direction). In this state, the follower means 2a can get over the cam groove 3a and the blocking rib 3b of the cam cylinder 3 by pushing the second lens holding means 2 into the cam cylinder 3 (image side direction). When the follower means 2a reaches the cam introduction groove 3g, the follower means 2a contacts the cam introduction groove 3g. Thereby, even if the cam groove 3c does not extend to the front surface of the cam cylinder 3 (the object-side surface that is the insertion surface of the second lens holding means 2 when the second lens holding means 2 is incorporated into the cam cylinder 3), It is possible to abut (fit) the follower means 2a and the cam groove 3c.

  Even when the cam tube 3 does not have the cam groove 3a, the cam groove 3c is formed only inside the cam tube 3, and the introduction portion of the cam groove 3c does not extend to the outside (front surface) of the cam tube 3, When the elastic means 2b is bent, the follower means 2a can be fitted into the cam groove 3c. Even if the introduction portion is not provided in the cam groove, the follower means 2a can be fitted into the cam groove 3c, so that the degree of freedom in design layout of the lens barrel 6 is increased.

  As shown in FIGS. 4 and 5a, an introduction slope 3d (first introduction part) that is a slope-shaped guide is formed in front of the cam cylinder 3 (object side). Therefore, by pushing the follower means 2a into the introduction slope 3d (first introduction slope) from the front, the follower means 2a and the elastic means 2b are easily displaced (deformed) toward the inner peripheral side of the cam cylinder 3, and the second The lens holding means 2 and the cam cylinder 3 can be easily assembled. In the present embodiment, an introduction slope 3e (second introduction portion) having a slope shape opposite to the introduction slope 3d is also formed at the boundary between the cam introduction groove 3g and the blocking rib 3b. Thereby, it is also easy to disassemble the second lens holding means 2 from the cam cylinder 3 (that is, to move the second lens holding means 2 to the object side that is opposite to the direction of assembly).

  As shown in FIG. 6a, the follower means 2a of the second lens holding means 2 is provided with drop-off prevention ribs 2c (protrusions) in the circumferential direction (R direction). The fixed cylinder 4 is formed with rectilinear restricting means 4b for guiding the follower means 2a rectilinearly. Thereby, the outer edge (tip portion) of the drop-off prevention rib 2c is configured to come into contact with the straight travel regulating means 4b. As shown in FIG. 6a, the fixed cylinder 4 has a follower means 4a-1 (fixed follower means) provided so as to follow the cam groove of the cam cylinder 3 and an inner circumferential direction (radial direction) by an elastic force. Displaceable follower means 4a-2, 4a-3 (elastic follower means) are provided.

  Since the follower means 2a is provided on the elastic means 2b, when the lens barrel 6 (digital camera 23) is subjected to an impact or dropped when the lens barrel 6 (digital camera 23) is used, the follower means 2a (elastic means 2b) is internally There is a possibility of bending to the circumferential side. For this reason, the follower drop-off restricting portion 4c (drop-off restricting portion) having a rib shape is provided on both sides of the straight advance restricting means 4b on the inner peripheral side of the straight advance restricting means 4b of the fixed cylinder 4. With such a configuration, even if the follower means 2a (elastic means 2b) bends to the inner peripheral side, the fall-off prevention rib 2c comes into contact with the follower drop-off restricting portion 4c, so that the follower means 2a is removed from the cam groove 3c. It is possible to effectively prevent the dropout.

  When the second lens holding means 2 is incorporated into the cam cylinder 3, the follower means 2a moves to the inner peripheral side by the elastic force of the elastic means 2b in order to get over the cam groove 3a. At this time, it is preferable that the drop-off prevention rib 2 c is configured not to interfere with the fixed cylinder 4. For this reason, in the range (range D1) in which the follower means 2a gets over the cam groove 3a and protrudes to the inner peripheral side (the range D1), the follower drop-off restricting portion 4c is not provided in the straight travel restriction means 4b, The follower drop-off restricting portion 4c is provided. As shown in the right side view of FIG. 6b (enlarged view of the front cross-sectional view in the range D1 of FIG. 5b), in the range D1, the follower drop-off restricting portion 4c is not formed in the straight travel restricting means 4b.

  As described above, the lens barrel 6 of the present embodiment includes a lens barrel (second lens) having the cam barrel 3 in which the cam groove 3c (first cam groove) is formed and the follower means 2a capable of following the cam groove 3c. Holding means 2). The lens holding means includes elastic means 2b that can be elastically displaced in the radial direction of the cam cylinder 3, and the follower means 2a is provided on the elastic means 2b. The cam groove 3c is formed within a predetermined range that does not include the end of the cam cylinder 3 (the end on the object side). When the lens holding means is incorporated in the cam cylinder 3, the follower means 2a enters the cam cylinder 3 while the elastic means 2b elastically deforms in the radial direction of the cam cylinder 3 (moves from the object side to the image side). And is inserted into the cam groove 3c (abuts against the cam groove 3c).

  Preferably, the cam cylinder 3 is formed with a second cam groove (cam groove 3a), and the cam groove 3c is formed within a predetermined range not including the second cam groove. When the lens holding means is incorporated in the cam cylinder 3, the follower means 2a retreats from the second cam groove while the elastic means 2b elastically deforms in the radial direction of the cam cylinder 3, and enters the inside of the cam cylinder 3. Inserted into the groove. More preferably, the lens barrel 6 has a fixed cylinder 4 having fixed cylinder follower means (follower means 4a) capable of following the second cam groove. The cam cylinder 3 is rotatable in the circumferential direction with respect to the fixed cylinder 4.

  Preferably, the fixed cylinder 4 has a rectilinear regulation means 4b that regulates the lens holding means in a straight line. The follower means 2a of the lens holding means is linearly guided by the straight advance restricting means 4b, so that the lens holding means can move linearly with respect to the fixed cylinder 4. More preferably, the follower means 2a of the lens holding means is provided with a protruding portion (drop-off preventing rib 2c) that prevents the straight-line restricting means 4b from dropping off. More preferably, the rectilinear restriction means 4b is provided with a drop-off restricting section (follower drop-off restricting section 4c) that prevents the follower means 2a from dropping off from the straight-running restricting means 4b. More preferably, the straight travel restricting means 4b is formed in a first region (range D1) that is closer than a predetermined distance from the second cam groove and a second region (range D2) that is farther than the predetermined distance. The drop-off restricting portion is provided in the second region of the straight travel restricting means 4b and is not provided in the first region. Preferably, the fixed cylinder follower means includes follower means 4a-2 and 4a-3 that can be displaced by elastic force.

  Preferably, the cam cylinder 3 is provided with a first introduction portion (introduction slope 3d) having a slope shape between the end of the cam cylinder 3 and the second cam groove. More preferably, the cam cylinder 3 has a second introduction portion (introduction slope 3e) having a slope shape opposite to the slope shape of the first introduction portion on the side opposite to the end of the cam cylinder 3 with respect to the second cam groove. ) Is provided. Preferably, the cam cylinder 3 is formed with a cam introduction groove 3g extending from the cam groove 3c between the cam groove 3c and the second cam groove. When the lens holding means is incorporated into the cam cylinder 3, the follower means 2a is inserted into the cam groove 3c after being inserted into the cam introduction groove 3g (the follower means 2a is in contact with the cam introduction groove 3g. To the cam groove 3c).

  In the lens barrel of the present embodiment, a plurality of cam grooves can be arranged so as to intersect without increasing the outer shape of the barrel and further increasing the number of parts, and the degree of freedom in design can be improved. . In addition, the lens barrel of this embodiment is resistant to dropping and impact, and is excellent in assembling workability. Therefore, according to the present embodiment, it is possible to provide a lens barrel and an imaging device that can be easily assembled with a small and simple configuration.

  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.

  The digital camera 23 of the present embodiment is an image pickup apparatus in which the lens barrel 6 and the image pickup apparatus main body having the image pickup element 15 are integrally configured, but the present invention is not limited to this. The present embodiment is also applicable to a lens device (lens barrel 6) that can be attached to and detached from the imaging apparatus main body.

2 Lens holding means 2a Follower means 2b Elastic means 3 Cam cylinder 3c Cam groove 6 Lens barrel

Claims (4)

A cam cylinder having a first cam groove formed on the inner periphery of the cylinder, and a second cam groove located at one end of the optical cam in a direction different from the first cam groove;
A first cam pin disposed on the inner peripheral side of the cam cylinder and inserted into the first cam groove, and the first cam pin moving in the first cam groove as the cam cylinder rotates is held. A lens holding member having an elastic part,
A lens barrel assembly method comprising:
The second cam groove is provided on the entire circumference of the cam cylinder,
When viewed from the radial direction of the cam cylinder, the introduction portions provided on both sides in the optical axis direction of the second cam groove with respect to the radial direction of the cam cylinder are more inside the cam cylinder than the first cam groove. Protruding toward the
When the lens holding member is incorporated in the cam cylinder, the first cam pin moves over the introduction part of the second cam groove by elastically deforming the elastic part toward the inside of the cam cylinder in the radial direction. A lens barrel assembling method, wherein the lens barrel is inserted into a first cam groove. A rectilinear cylinder provided on the outer side of the cam cylinder and having a rectilinear groove for regulating the lens holding member so as to linearly travel;
The rectilinear groove is provided with a first region in which a drop-out restricting portion that prevents the first cam pin from dropping out of the straight advance groove is provided, and the drop-out restricting portion on the other side in the optical axis direction than the first region. The second cam groove introduction portion is provided at a position overlapping the first region when viewed from the radial direction. To assemble the lens barrel.   When viewed from the radial direction of the cam cylinder, with respect to the radial direction of the cam cylinder, the tip of the first cam pin has a tapered shape protruding toward the outside of the cam cylinder, and the optical axis of the second cam groove 3. The lens barrel according to claim 1, wherein the leading ends of the introduction portions provided on both sides of the direction have a tapered shape protruding toward the inside of the cam cylinder in a radial direction of the cam cylinder. Assembly method.   4. The lens barrel assembling method according to claim 1, further comprising a second cam pin that engages with the second cam groove on an inner periphery of the rectilinear barrel. 5.