JP2009036827A - Diaphragm regulator for lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure sufficient mechanical strength (durability), reliability and space-saving properties, and to attain advantages in terms of assembling and a cost. <P>SOLUTION: This diaphragm regulator is provided with a locking recess 11 on the inner circumferential face 4i of a diaphragm ring 4, stores an operation part 12 with a button part 12b projected radially outward in an inside of the locking recess 11, and is provided with a holding recess 13 on an outer circumferential face 3o of a mount base 3, stores an L-shaped locking cam 14 freely displaceably in the holding recess 13, and is provided with a locking mechanism 5, capable of pressure-contacting tip end parts 14s, 14t of the locking cam 14 onto the inner circumferential face 4i of the diaphragm ring 4, with energization by a spring member 15. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lens aperture adjusting device including an aperture ring having a manual adjustment function for performing aperture adjustment in a manual adjustment mode and a mode switching function for switching between the manual adjustment mode and the auto adjustment mode.

  In general, a lens mounted on a still camera or an interchangeable lens mounted on a single-lens reflex camera is provided with an aperture adjusting device that adjusts an aperture. Normally, this type of aperture adjusting device is attached to a lens barrel, and Mount base equipped with a diaphragm mechanism, supported by this mount base so as to be rotatable, and a manual adjustment function for adjusting the diaphragm in a manual adjustment mode within a predetermined rotation angle range and an automatic adjustment mode at the end position of the rotation angle range A diaphragm ring having a mode switching function for switching to a mode, and a lock mechanism unit for locking the mode switching function by non-operation and releasing the lock by operation. In this case, the manual adjustment mode is a mode in which an arbitrary F value (aperture value) corresponding to the rotation angle is set by manually rotating the aperture ring, and the auto adjustment mode is AE (automatic exposure). In this mode, the F value is automatically set by operation.

Conventionally, as this type of aperture adjusting device, an automatic / manual switching device for an aperture ring in a lens barrel disclosed in Patent Document 1 is known. The switching device is a lens barrel for a camera that switches between a manually set aperture operation and an auto set aperture operation according to the rotation angle of the aperture ring. The lens barrel has a substantially cylindrical shape and a notch is formed over a predetermined angle range. A fixed member, a diaphragm ring that is rotatably fitted to the outer periphery of the lens barrel fixing member by a predetermined rotation angle and has a protruding portion that protrudes into the notch, and a radius at a portion where the protruding portion of the diaphragm ring is provided A lock that is supported so as to be movable back and forth along the direction, and is provided so that a part protrudes to the outer peripheral surface side of the aperture ring while being biased to at least the outer peripheral side, and an engaging protrusion projects from the inner end side A member, an elastic member that constantly urges the locking portion toward the outer peripheral surface side, and a lens barrel fixing member that protrudes so as to correspond to the engaging protrusion of the locking member, and the locking member is biased toward the outer peripheral side. In the engaged projection And a stopper member that is disengaged in a state where the locking member is moved to the inner peripheral side against the biasing force of the elastic member when the locking member is pressed on the outer peripheral side protruding portion. When switched to the manually set aperture operation, the engagement protrusion of the locking member and the stopper member abut, the projection of the aperture ring and the one side wall of the notch formed in the lens barrel fixing member When the rotation angle of the aperture ring is restricted to the angle range between the open aperture position and the minimum aperture position and is switched to the automatic setting aperture operation, the contact between the engagement protrusion and the stopper member, the protrusion and the notch The rotation of the aperture ring is prevented by contact with the other side wall.
Japanese Utility Model Sho 61-39379

  However, the above-described conventional lens aperture adjusting device (automatic / manual switching device for the aperture ring in the lens barrel) has the following problems.

  First, since the engaging projections that become pin-like bodies are switched over the stopper member, the width dimension in the circumferential direction of the engaging projections cannot be set too large. Therefore, there is a possibility that the engaging projection may be damaged due to a large operating force on the aperture ring or physical fatigue due to long-term use, and sufficient mechanical strength (durability) and further reliability cannot be ensured.

  Secondly, since the engaging protrusion moves over the stopper member, the displacement of the engaging protrusion inward in the radial direction (displacement amount) increases, leading to an increase in the size of the entire mechanism, resulting in poor space saving. In addition, since the number of small parts increases, it is disadvantageous in terms of assembly and cost.

  The object of the present invention is to provide a lens iris adjusting device that solves the problems existing in the background art.

  In order to solve the above-described problems, the present invention is attached to the lens barrel 50 and provided with a mount base 3 including the diaphragm mechanism 2, and is rotatably supported by the mount base 3, and has a predetermined rotation angle range Zr. (Xs to Xo), the aperture ring 4 having a manual adjustment function for adjusting the aperture in the manual adjustment mode and a mode switching function for switching to the automatic adjustment mode at the end position Xa of the rotation angle range Zr, and a mode switching function by non-operation. When the lens diaphragm adjusting device 1 having the lock mechanism unit 5 that locks and releases the lock by an operation is provided, a locking recess 11 is provided on the inner peripheral surface 4 i of the aperture ring 4. While accommodating the operation part 12 which made the button part 12b protrude radially outside inside, the holding recessed part 13 is provided in the outer peripheral surface 3o of the mount base 3, An L-shaped lock cam 14 is slidably accommodated in the holding recess 13 and is urged by a spring material 15 so that the tip end portions 14 s and 14 t of the lock cam 14 can be pressed against the inner peripheral surface 4 i of the aperture ring 4. A mechanism unit 5 is provided.

  In this case, according to a preferred aspect of the invention, a stopper mechanism portion 16 that restricts the rotation angle range Zr can be provided in a portion other than the lock mechanism portion 5. The spring material 15 can be a leaf spring portion 15p that is pressed against the intermediate bent portion 14m of the lock cam 14. At this time, a holding plate portion 17 that holds the lock cam 14 is integrated with the leaf spring portion 15p. Can be formed.

  According to the lens aperture adjusting device 1 according to the present invention having such a configuration, the following remarkable effects can be obtained.

  (1) The operation portion 12 in which the button portion 12b protrudes radially outward is accommodated in the engaging recess 11 provided on the inner peripheral surface 4i of the aperture ring 4, and provided on the outer peripheral surface 3o of the mount base 3. Since the L-shaped lock cam 14 is slidably accommodated in the holding recess 13 and urged by the spring material 15, the front end portions 14 s and 14 t of the lock cam 14 can be pressed against the inner peripheral surface 4 i of the aperture ring 4. Conventional pin-shaped parts are not required. Therefore, there is no possibility that the operating force with respect to the aperture ring 4 is large or that it is damaged even after long-term use, and sufficient mechanical strength (durability) and further reliability can be secured.

  (2) Since the L-shaped lock cam 14 is mainly displaced in a seesaw shape and switched, the radial inward displacement (displacement amount) can be reduced. Therefore, since the space occupied by the entire mechanism can be reduced, it is excellent in space saving and small parts are unnecessary, which is advantageous in terms of assembly and cost.

  (3) If a stopper mechanism portion 16 that restricts the rotation angle range Zr is provided in a portion other than the lock mechanism portion 5 according to a preferred embodiment, interference with the lock mechanism portion 5 can be avoided, and the degree of freedom in design and space can be avoided. Efficiency can be further increased.

  (4) According to a preferred embodiment, the spring material 15 is provided with a leaf spring portion 15p that is pressed against the intermediate bent portion 14m of the lock cam 14, and a holding plate portion 17 that holds the lock cam 14 is integrated with the leaf spring portion 15p. If formed, it can contribute to further reduction of the number of parts and improvement of assemblability.

  Next, the best embodiment according to the present invention will be given and described in detail with reference to the drawings.

  First, the configuration of the lens aperture adjusting device 1 according to the present embodiment will be described with reference to FIGS.

  In FIG. 5, the interchangeable lens 60 including the aperture adjusting device 1 is indicated by a virtual line, and the interchangeable lens 60 is attached to and detached from the camera body 61. The interchangeable lens 60 includes a lens barrel 50, and the lens barrel 50 incorporates a plurality of lenses (lens group). The aperture adjusting device 1 is provided at the rear end of the lens barrel 50. The aperture adjustment device 1 includes a mount base 3, an aperture ring 4 and a lock mechanism 5 as a basic configuration.

  As shown in FIGS. 1 and 2A, the mount base 3 is formed in a flat cylindrical shape, and includes a known diaphragm mechanism 2 constituted by a plurality of diaphragm blades. The mount base 3 is attached to the rear end of the lens barrel 50. Further, a ring loading surface 3s for loading the aperture ring 4 is provided on a part of the outer circumferential surface 3o of the mount base 3, and as shown in FIG. 5, the upper surface position of the outer circumferential surface 3o exposed to the outside is formed by dots. The indicator part 65 is displayed.

  The diaphragm ring 4 is formed in a ring shape as shown in FIG. 2B, and a supported surface 4s supported by the ring loading surface 3s of the mount base 3 is provided on a part of the inner peripheral surface 4i. Thereby, when the aperture ring 4 is assembled to the mount base 3, the supported surface 4 s of the aperture ring 4 is rotatably supported by the ring loading surface 3 s of the mount base 3. FIG. 2A shows the aperture ring 4 assembled to the mount base 3 by phantom lines. The diaphragm ring 4 has a manual adjustment function for adjusting the diaphragm in the manual adjustment mode within a predetermined rotation angle range Zr (Xs to Xo) and a mode switching function for switching to the automatic adjustment mode at the end position Xa of the rotation angle range Zr. Is provided. Therefore, as shown in FIG. 5, the aperture ring 4 has an F-value scale unit 66 instructed by the index unit 65 and a switching position of the auto adjustment mode when performing the diaphragm adjustment in the manual adjustment mode. The auto display unit 67 is displayed. The button part 12b in the lock mechanism part 5 is exposed adjacent to the auto display part 67.

  On the other hand, the lock mechanism unit 5 has a function of locking the mode switching function by non-operation and releasing the lock by operation, and the lock mechanism unit 5 constitutes a main part of the present invention. As shown in FIG. 1, the lock mechanism unit 5 includes a locking recess 11 formed on the inner peripheral surface 4 i of the aperture ring 4 and an operation unit 12 accommodated in the locking recess 11. The operation part 12 has a cylindrical button part 12b and a retaining part 12s formed wide at the lower end of the button part 12b. Further, an insertion hole portion 11 h through which the button portion 12 b is inserted is formed through the locking recess 11 to the outer peripheral surface of the aperture ring 4. Accordingly, when the operation portion 12 is accommodated in the locking recess 11, the button portion 12b protrudes radially outward through the insertion hole portion 11h, and the retaining portion 12s is locked in the locking recess 11 to the outside. Omission is prevented.

  Further, as shown in FIG. 1, the lock mechanism 5 includes a holding recess 13 provided on the outer peripheral surface 3 o of the mount base 3, a lock cam 14 that is slidably accommodated in the holding recess 13, and the lock cam 14. A spring member 15 is provided that presses the distal end portions 14s and 14t of the lock cam 14 against the inner peripheral surface 4i of the aperture ring 4 by urging. FIG. 3A shows a rear view of the lock cam 14, and FIG. 3B shows a side view of the lock cam 14. The lock cam 14 is a flat plate having a predetermined thickness, and is formed in an L shape as a whole. For this reason, it has the 1st lock part 21 and the 2nd lock part 22 which were extended from the intermediate | middle bending part 14m at a different angle, while having the front-end | tip part 14s in the 1st lock part 21, and the front-end | tip part in the 2nd lock part 22 14t. Further, a semi-circular portion where the spring material 15 is pressed against is provided in the intermediate bent portion 14m. On the other hand, FIG. 4 shows the spring material 15. The spring material 15 is integrally formed with the mounting plate portion 26 having a mounting hole 26 h through which the fixing screw 25 is inserted, the holding plate portion 26 that holds the lock cam 14, and the mounting plate portion 26. And a leaf spring portion 15p positioned at a right angle to the mounting plate portion 26. Accordingly, the leaf spring portion 15p is pressed against the intermediate bent portion 14m of the lock cam 14, and the lock cam 14 is urged radially outward by the leaf spring portion 15p.

  Therefore, the holding recess 13 has a support surface 27 (FIG. 2) that supports one end surface of the lock cam 14 when the lock cam 14 is accommodated, and an insertion recess 28 that allows the intermediate bent portion 14m to protrude. The holding recess 13 (lock cam 14) has a circumferential dimension that is much longer than the circumferential dimension of the locking recess 11 (approximately 1.5 times). Accordingly, the holding recess 13 allows displacement to a position where the tip portions 14s and 14t of the lock cam 14 protrude outward from the outer peripheral surface 3o or a position where the tip portions 14s and 14t do not protrude outward from the outer peripheral surface 3o. At the same time, a seesaw-like displacement is allowed with respect to the lock cam 14. As shown in FIG. 1, when the spring material 15 is attached to the mount base 3 with the fixing screw 25, the leaf spring portion 15 p is pressed against the intermediate bent portion 14 m of the lock cam 14, and the other end surface of the lock cam 14 is Holding plate 17 holds. As described above, when the leaf spring portion 15p pressed against the intermediate bent portion 14m of the lock cam 14 is used as the spring material 15, and the holding plate portion 17 holding the lock cam 14 is integrally formed with the leaf spring portion 15p, There is an advantage that it can contribute to further reduction of the number of parts and improvement of assembly.

  On the other hand, a stopper mechanism portion 16 that restricts the rotation angle range Zr is provided at a portion other than the lock mechanism portion 5. The stopper mechanism portion 16 is constituted by a locking portion 31 provided on the aperture ring 4 side and a pair of restricting portions 32 and 33 provided on the mount base 3 side. In this case, as shown in FIG. 2 (FIG. 1), the locking portion 31 is an integral part of the inner peripheral surface 4 i of the aperture ring 4 that is offset in the axial direction with respect to the position where the operation portion 12 is disposed. Form. Further, as shown in FIG. 1, the pair of restricting portions 32 and 33 are the outer peripheral surface 3 o of the mount base 3, and the maximum throttle position in the rotation angle range Zr at the axial position corresponding to the locking portion 31. A restricting portion 32 that restricts Xo (F value: 3.5) is integrally formed, and a restricting portion 33 that restricts the minimum aperture position Xs (F value: 22) of the rotation angle range Zr is integrally formed. Thus, if the stopper mechanism part 16 is provided in parts other than the lock mechanism part 5, there exists an advantage which can avoid interference with the lock mechanism part 5 and can improve a design freedom and space efficiency more.

  Next, the function of the aperture adjusting device 1 according to the present embodiment will be described with reference to the drawings and FIGS.

  First, the manual adjustment mode will be described. FIG. 6 shows a state in which the aperture ring 4 is at the maximum aperture position Xo in the manual adjustment mode. At the maximum aperture position Xo, the locking recess 11 provided in the aperture ring 4 is separated from the holding recess 13 provided in the mount base 3, so that the retaining portion 12 s of the operation portion 12 contacts the outer peripheral surface 3 o of the mount base 3. That is, the button portion 12 b is in a position that does not protrude from the outer peripheral surface of the aperture ring 4, and the tip portions 14 s and 14 t of the lock cam 14 abut on the inner peripheral surface 4 i of the aperture ring 4. In this case, since the lock cam 14 contacts the inner peripheral surface 4i, the lock cam 14 is pushed inward in the radial direction of the mount base 3 against the elasticity of the leaf spring portion 15p. Accordingly, the aperture ring 4 at the maximum aperture position Xo can be freely rotated and displaced toward the minimum aperture position Xs side, and the locking portion 31 provided on the aperture ring 4 is a restriction portion 32 provided on the mount base 3. Therefore, the rotational displacement in the opposite direction is prevented (restricted). If the aperture ring 4 is rotationally displaced to an arbitrary angular position by manual adjustment, the F value (incident light amount) of the aperture mechanism 2 is set in conjunction with this angular position.

  On the other hand, it is assumed that the aperture ring 4 is rotationally displaced from the maximum aperture position Xo to the minimum aperture position Xs. FIG. 7 shows a state in which the aperture ring 4 is at the minimum aperture position Xs. At the minimum throttle position Xs, since the locking recess 11 provided in the aperture ring 4 faces the holding recess 13 provided in the mount base 3, the distal end portion 14s of the lock cam 14 biased by the leaf spring portion 15p, that is, the first One lock portion 21 enters the locking recess 11. As a result, since the first lock portion 21 and the locking recess 11 are locked, the rotational displacement toward the end position Xa beyond the minimum throttle position Xs is prevented. However, even when the first lock portion 21 enters the locking recess 11, the rotational displacement toward the maximum throttle position Xo is allowed due to the shape of the lock cam 14. As described above, when adjusting the aperture in the manual adjustment mode (manual adjustment function), the F value can be arbitrarily set between the maximum aperture position Xo and the minimum aperture position Xs by manual operation of the aperture ring 4, and the lock mechanism. Locked to the manual adjustment function by the unit 5.

  Next, the auto adjustment mode will be described. FIG. 8 shows a state in which the aperture ring 4 is positioned at the end position Xa of the rotation angle range Zr. In this case, if the user presses the button portion 12b with his / her hand in the minimum throttle position Xs, that is, the state shown in FIG. 7 and forcibly pushes the first lock portion 21 inward in the radial direction, Since the locking of the locking recess 11 is released, the aperture ring 4 can be rotationally displaced from the minimum aperture position Xs to the end position Xa. When the user releases his / her hand from the button portion 12b at the end position Xa, the tip end portion 14t of the lock cam 14 urged by the leaf spring portion 15p, that is, the second lock portion 22 enters the locking recess 11. . At this time, the distal end portion 14 s of the first lock portion 21 is in contact with the inner peripheral surface 4 i of the aperture ring 4. As a result, when the aperture ring 4 is at the end position Xa, as shown in FIG. 8, the locking portion 31 provided on the aperture ring 4 comes into contact with the restricting portion 33 provided on the mount base 3 so that the position is reached. In addition to being restricted, the second lock portion 22 and the locking recess 11 are locked to prevent the rotational displacement toward the maximum throttle position Xo, and the throttle ring 4 is held at the end position Xa. In this case, as shown in FIG. 5, the indicator unit 65 instructs the auto display unit 67. On the other hand, if the user pushes the button portion 12b by hand in the state shown in FIG. 8 and forcibly pushes the second lock portion 22 radially inward, the second lock portion 22 and the locking recess 11 are locked. Therefore, the aperture ring 4 can be rotationally displaced from the end position Xa to the minimum aperture position Xs side. That is, it is possible to switch to the manual adjustment mode. Therefore, the lock mechanism unit 5 can lock the mode switching function by not operating the button unit 12b, and can release the lock by operating the button unit 12b.

  Therefore, according to the diaphragm adjusting apparatus 1 according to the present embodiment, the operation part in which the button part 12b is protruded radially outside in the locking recess 11 provided in the inner peripheral surface 4i of the diaphragm ring 4. 12, and an L-shaped lock cam 14 is housed in a holding recess 13 provided on the outer peripheral surface 3 o of the mount base 3 so as to be displaceable, and is urged by a spring material 15 to be on the front end portions 14 s and 14 t of the lock cam 14. Can be press-contacted to the inner peripheral surface 4i of the aperture ring 4, so that conventional pin-shaped parts are not required. Therefore, there is no possibility that the operating force with respect to the aperture ring 4 is large or that it is damaged even after long-term use, and sufficient mechanical strength (durability) and further reliability can be secured. Further, since the L-shaped lock cam 14 is switched mainly by being displaced in a seesaw shape, the radially inward displacement (displacement amount) can be reduced. Therefore, since the space occupied by the entire mechanism can be reduced, it is excellent in space saving and small parts are unnecessary, which is advantageous in terms of assembly and cost.

  Although the best embodiment has been described in detail above, the present invention is not limited to such an embodiment, and departs from the gist of the present invention in the detailed configuration, shape, material, quantity, numerical value, and the like. It can be changed, added, or deleted as long as it is not.

  For example, as the spring material 15, the leaf spring portion 15 p pressed against the intermediate bent portion 14 m of the lock cam 14 is used, but the use of other spring materials such as a coil spring is not excluded. Therefore, in this case, a separate holding plate portion 17 can be used, and other holding means for holding the lock cam 14 can be used if necessary. The L-shaped lock cam 14 is a concept including various similar shapes such as a dogleg shape and a boomerang shape, which have a function of being switched in a seesaw shape. Although the diaphragm adjusting device 1 according to the present invention is applied to the interchangeable lens 60, it does not matter whether the lens is the interchangeable lens 60 or the camera integrated type. In addition, the aperture adjusting device 1 according to the present invention can be used for various optical devices that require similar functions, such as still cameras and video cameras.

The rear view of the principal part containing the extraction enlarged view which fractured | ruptured a part of iris diaphragm adjustment device concerning the best embodiment of the present invention, Part drawing including a side view of a mount base and a sectional view of a diaphragm ring used in the diaphragm adjusting device, Part drawing including a rear view and a side view of a lock cam used in the diaphragm adjusting device, A perspective view of a spring material used in the diaphragm adjusting device, A plan view of an interchangeable lens provided with the same diaphragm adjusting device, Functional explanatory diagram of the aperture adjustment device, Other function explanatory drawing of the same diaphragm adjusting device, Other function explanatory drawing of the same diaphragm adjusting device,

Explanation of symbols

  1: aperture adjusting device, 2: aperture mechanism, 3: mount base, 3o: outer peripheral surface of mount base, 4: aperture ring, 4i: inner peripheral surface of aperture ring, 5: lock mechanism, 11: locking recess, 12: operation part, 12b: button part, 13: holding recess, 14: lock cam, 14s: tip part of lock cam, 14t: tip part of lock cam, 14m: intermediate bent part of lock cam, 15: spring material, 15p: leaf spring 16, 16: Stopper mechanism, 17: Holding plate, 50: Lens barrel, Zr: Rotation angle range, Xa: End position of rotation angle range

Claims (4)

  A mount base attached to the lens barrel and provided with a diaphragm mechanism, a manual adjustment function that is supported rotatably by the mount base, and performs diaphragm adjustment in a manual adjustment mode within a predetermined rotation angle range, and the rotation angle In a lens aperture adjusting device comprising an aperture ring having a mode switching function for switching to an auto adjustment mode at the end position of the range, and a lock mechanism unit that locks the mode switching function by non-operation and releases the lock by operation, A locking recess is provided on the inner peripheral surface of the aperture ring, and an operation portion in which the button portion protrudes radially outward is accommodated in the locking recess, and a holding recess is provided on the outer peripheral surface of the mount base, An L-shaped lock cam is slidably accommodated in the holding recess, and is urged by a spring material so that the tip end side of the lock cam is the throttle Lens aperture adjustment device, characterized in that it comprises a locking mechanism which enables pressure contact with the inner peripheral surface of ring.   The lens diaphragm adjusting device according to claim 1, wherein a stopper mechanism for restricting the rotation angle range is provided at a portion other than the lock mechanism.   2. The lens diaphragm adjusting device according to claim 1, wherein the spring material uses a leaf spring portion that is pressed against an intermediate bent portion of the lock cam.   4. The lens aperture adjusting device according to claim 3, wherein a holding plate portion for holding the lock cam is formed integrally with the leaf spring portion.

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