JP2011141403A - Optical element switching mechanism and lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To selectively position a desired optical element out of a plurality of optical elements on an optical path while suppressing an enlargement of a lens barrel in an outer diameter direction and in an optical axis direction. <P>SOLUTION: An optical element switching mechanism includes a fixed base member 202 having an opening part 202a through which light of a subject passes, a turntable supported rotatably around an optical axis for the fixed base member 202, and one holding member 201 for holding a plurality of ND filters 301. By moving the holding member 201 roughly translationally along the plane perpendicular to the optical axis with the rotation of the turntable for the fixed base member 202, switching among the ND filters 301A, 301B, 301C and an opening 201d is performed so that any one of the plurality of the ND filters 301 (301A, 301B, and 301C) and the opening 201d may overlap with the opening part 202a in the optical axis direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention includes a plurality of optical elements, an optical element switching mechanism that appropriately switches an optical element positioned in an optical path so that a desired optical element among the plurality of optical elements can be selectively used, and the optical The present invention relates to a lens barrel provided with an element switching mechanism.

  Conventionally, for example, ND filter switching that includes a plurality of ND filters having different densities and switches the position of each ND filter relative to the optical path so that a desired ND filter among the ND filters is selectively positioned on the optical path. There was a lens device with a mechanism. A lens apparatus equipped with such an ND filter switching mechanism is incident on the lens barrel by switching the position of each filter so that a desired ND filter is selectively positioned on the optical path in accordance with a shooting situation or the like. The amount of external light to be adjusted can be adjusted in multiple stages.

  As described above, conventionally, among a plurality of optical elements such as a plurality of ND filters having different densities, the optical element positioned on the optical path can be switched so that the desired optical element is selectively positioned on the optical path. And an optical device provided with the optical element switching mechanism. An example of a conventional optical element switching mechanism in such an optical device will be described.

  26, 27, and 28 are explanatory views showing an example of a conventional ND filter switching mechanism. 26, 27 and 28, the conventional ND filter switching mechanism 2600 includes a turret 2602 that supports a plurality of ND filters 2601. The turret 2602 is provided so as to be rotatable about a rotation shaft 2604 provided at a position retracted from the optical path 2603. A switching lever 2605 for rotating the turret 2602 is connected to the turret 2602 via transmission gears 2701, 2702 and the like.

  In the turret 2602 provided in the conventional ND filter switching mechanism 2600, each ND filter 2601 is supported in a positional relationship such that the distances to the rotating shaft 2604 are equal. That is, each ND filter 2601 is provided on the same circumference with the rotation shaft 2604 as the center. The distance between each ND filter 2601 and the rotation shaft 2604 is equal to the distance between the optical path 2603 and the rotation shaft 2604, respectively.

  In the conventional ND filter switching mechanism 2600 having such a configuration, when the operator of the ND filter switching mechanism 2600 operates the switching lever 2605, the transmission gears 2701, 2702, etc. are interlocked with the operation of the switching lever 2605. The turret 2602 connected to the switching lever 2605 rotates about the rotation shaft 2604 (see FIG. 26). The distance between each ND filter 2601 and the rotation shaft 2604 is equal to the distance between the optical path 2603 and the rotation shaft 2604, respectively.

  For this reason, the ND filter 2601 positioned on the optical path 2603 can be selectively switched by the rotation of the turret 2602 around the rotation shaft 2604. That is, there has been a technique in which the thickness in the optical axis direction is suppressed by attaching a plurality of filters to one holding frame and by using one rotation fulcrum of the switching mechanism.

  Conventionally, for example, a filter is housed and installed together with a switching mechanism and a housing mechanism between a low-pass filter and a spectroscopic prism on the optical path that is the smallest regardless of the aperture of the imaging lens. A dummy glass that is placed on the optical path by a flower-cart-like cam stacked and accommodated by a rotating holder, and when only one filter is excluded from the optical path, such as when the filter is not used, is held on a separate shaft. There has been a technique that is configured to automatically return to (for example, see Patent Document 1 below).

  Specifically, in the technique described in Patent Document 1, a plurality of filters are attached to respective holders (holding frames), and the respective holding frames are arranged so as to overlap each other in the optical axis direction. An ND filter switching mechanism (a high-definition camera filter storage and exchange mechanism) that does not protrude beyond the outer diameter of the cylinder is realized.

  Conventionally, the holder holding the ND filter is moved in and out in the direction perpendicular to the optical axis with the fulcrum axis as the center, and an operating piece protruding from the lens barrel is provided at the end extending from the fulcrum axis. A rotating link is arranged so as to be pivotable about the fulcrum axis along the outer surface of the lens barrel, and an operation piece to be engaged with the operating piece of the holder is provided on one end side of the rotating link and in the turning direction. There has been a technology that configures a link mechanism in which a toggle spring that is urged by a spring is provided on a rotating link, and the other end side of the rotating link is turned by a switching operation of a slide knob provided on an external housing (for example, (See Patent Document 2 below.)

Utility model registration No. 3146554 JP 11-194417 A

  However, in the conventional technique shown in FIG. 26, FIG. 27 and FIG. 28 described above, there is one rotational fulcrum (rotating shaft 2604) of the turret 2602 in the ND filter switching mechanism 2600 for a plurality of ND filters 2601. Therefore, when the ND filter 2601 is switched, a part of the turret 2602 protrudes outside the outer diameter of the lens barrel (a dotted frame 2610 in FIGS. 26 and 28 and a dotted frame 2800 in FIG. 28). See). For this reason, there existed a problem that size reduction in the radial direction of a lens-barrel was difficult.

  In addition, in the conventional technique described in Patent Document 1 described above, it is possible to achieve downsizing in the outer diameter direction of the lens barrel, but because it is a structure in which a plurality of filters are arranged to overlap in the optical axis direction, There was a problem that downsizing in the optical axis direction was difficult.

  Further, in the conventional technique described in Patent Document 2 described above, it is necessary to provide a link mechanism for moving the ND filter in and out of each ND filter. That is, in a lens apparatus provided with a plurality of ND filters, a plurality of link mechanisms are required. For this reason, there are problems that the number of parts increases and the structure becomes complicated.

  In order to solve the above-described problems caused by the conventional technology, the present invention selectively suppresses the desired optical element among the plurality of optical elements while suppressing the increase in the size of the lens barrel in the outer diameter direction and the optical axis direction. An object of the present invention is to provide an optical element switching mechanism that can be positioned on a road.

  In order to solve the above-described problems and achieve the object, an optical element switching mechanism according to the present invention includes a fixed base member having an opening through which light of a subject passes, and a rotation around the optical axis with respect to the fixed base member. A rotating member that is movably supported, a holding member that holds a plurality of optical elements on substantially the same plane, and with respect to the optical axis as the rotating member rotates relative to the fixed base member. Switching the optical element so that any one of the plurality of optical elements moves to a position overlapping with the opening by moving the holding member substantially along a plane orthogonal to each other. And a guide mechanism for performing the above.

  The optical element switching mechanism according to the present invention is the optical element switching mechanism according to the first aspect, wherein the guide mechanism is a cam pin provided in the holding member, and a first cam groove provided in the fixed base member and fitted with the cam pin. And a second cam groove provided in the rotating member and fitted with the cam pin, wherein the first cam groove is substantially parallel to a first direction extending along the plane. A first direction cam groove having a direction as a longitudinal direction, and a second direction cam extending along the plane and having a direction substantially parallel to a second direction orthogonal to the first direction as a longitudinal direction And the second cam groove holds the fitted cam pin and transmits the rotational force of the rotating member to the cam pin. The rotating member rotates at a predetermined angle. Through the second cam groove when moved By moving the holding member substantially in translation by moving the cam pin to a predetermined position in the first cam groove, any one of the plurality of optical elements overlaps the opening. The optical element is switched so as to move to a position.

  In the optical element switching mechanism according to the present invention as set forth in the invention described above, the fixed base member includes a substantially square notch, and is provided inside the notch while supporting the rotating member. A shaft member having an inner periphery having a second opening through which light of the subject passes and an outer periphery having a substantially square shape. The guide mechanism includes a cam pin provided in the holding member, the notch, and the notch A first cam groove formed by a shaft member into which the cam pin is fitted, and a second cam groove provided in the rotating member and into which the cam pin is fitted, wherein the second cam groove is And holding the fitted cam pin and transmitting the rotational force of the rotating member to the cam pin, and when the rotating member is rotated by a predetermined angle, the second cam groove A cam pin in the first cam groove The optical element is moved so that any one of the plurality of optical elements moves to a position overlapping the opening by moving the holding member substantially in translation by moving the holding member to a predetermined position. It is characterized by switching.

  In the optical element switching mechanism according to the present invention, in the above invention, the fixed base member contacts the holding member when the cam pin is moved to the predetermined position in the first cam groove. Thus, a rotation restricting portion for restricting the rotation of the holding member is provided.

  Further, in the optical element switching mechanism according to the present invention, in the above invention, when the rotating member is rotated to the predetermined angle, a locking receiving portion provided on the outer peripheral side of the rotating member; The rotating member is engaged with a biasing member provided along a direction orthogonal to the optical axis, with one end fixed to the base member and the other end biasing toward the optical axis. It is characterized by being stopped.

  In the optical element switching mechanism according to the present invention as set forth in the invention described above, the optical element is a filter.

  In addition, a lens barrel according to the present invention includes the optical element switching mechanism described above.

  According to the optical element switching mechanism according to the present invention, it is possible to selectively position a desired optical element among the plurality of optical elements on the optical path while suppressing an increase in the size of the lens barrel in the outer diameter direction and the optical axis direction. There is an effect that can be.

It is explanatory drawing which shows the lens apparatus of embodiment concerning this invention. It is explanatory drawing (the 1) which shows the optical filter switching mechanism of embodiment concerning this invention. It is explanatory drawing (the 2) which shows the optical filter switching mechanism of embodiment concerning this invention. It is explanatory drawing (the 3) which shows the optical filter switching mechanism of embodiment concerning this invention. It is explanatory drawing (the 1) which shows each state which the optical filter switching mechanism of embodiment concerning this invention can take. It is explanatory drawing (the 2) which shows each state which the optical filter switching mechanism of embodiment concerning this invention can take. It is explanatory drawing (the 3) which shows each state which the optical filter switching mechanism of embodiment concerning this invention can take. It is explanatory drawing (the 4) which shows each state which the optical filter switching mechanism of embodiment concerning this invention can take. It is explanatory drawing (the 1) which shows the positional relationship of each part with which the optical filter switching mechanism of embodiment concerning this invention is provided. It is explanatory drawing (the 2) which shows the positional relationship of each part with which the optical filter switching mechanism of embodiment concerning this invention is provided. It is explanatory drawing (the 3) which shows the positional relationship of each part with which the optical filter switching mechanism of embodiment concerning this invention is provided. It is explanatory drawing (the 1) which shows the positional relationship of each part in each state which the optical filter switching mechanism of embodiment concerning this invention can take. It is explanatory drawing (the 2) which shows the positional relationship of each part in each state which the optical filter switching mechanism of embodiment concerning this invention can take. It is explanatory drawing (the 3) which shows the positional relationship of each part in each state which the optical filter switching mechanism of embodiment concerning this invention can take. It is explanatory drawing (the 4) which shows the positional relationship of each part in each state which the optical filter switching mechanism of embodiment concerning this invention can take. It is explanatory drawing (the 5) which shows the positional relationship of each part in each state which the optical filter switching mechanism of embodiment concerning this invention can take. It is explanatory drawing (the 6) which shows the positional relationship of each part in each state which the optical filter switching mechanism of embodiment concerning this invention can take. It is explanatory drawing (the 7) which shows the positional relationship of each part in each state which the optical filter switching mechanism of embodiment concerning this invention can take. It is explanatory drawing (the 1) which shows the optical filter switching mechanism of another embodiment concerning this invention. It is explanatory drawing (the 2) which shows the optical filter switching mechanism of another embodiment concerning this invention. It is explanatory drawing (the 3) which shows the optical filter switching mechanism of another embodiment concerning this invention. It is explanatory drawing (the 4) which shows the optical filter switching mechanism of another embodiment concerning this invention. It is explanatory drawing (the 5) which shows the optical filter switching mechanism of another embodiment concerning this invention. It is explanatory drawing (the 6) which shows the optical filter switching mechanism of another embodiment concerning this invention. It is explanatory drawing (the 7) which shows the optical filter switching mechanism of another embodiment concerning this invention. It is explanatory drawing (the 1) which shows an example of the conventional ND filter switching mechanism. It is explanatory drawing (the 2) which shows an example of the conventional ND filter switching mechanism. It is explanatory drawing (the 3) which shows an example of the conventional ND filter switching mechanism.

  Exemplary embodiments of an optical element switching mechanism according to the present invention and a lens barrel including the optical element switching mechanism will be described below in detail with reference to the accompanying drawings.

  First, the configuration of an optical element switching mechanism and a lens barrel including the optical element switching mechanism according to an embodiment of the present invention will be described. FIG. 1 is an explanatory view showing a lens barrel of an embodiment according to the present invention. FIG. 1 shows a cross section of a lens barrel according to an embodiment of the present invention cut along a plane passing through the optical axis and parallel to the optical axis.

  In FIG. 1, a lens barrel 100 according to an embodiment of the present invention includes a barrel 101. The lens barrel 101 has a substantially cylindrical shape. In the lens barrel 101, openings 102 and 103 that open the inside of the lens barrel 101 to the outside are provided at the end portions on the eyepiece side and the object side, respectively. The lens barrel 101 is attached to the main body of the imaging device with the end portion on the eyepiece side (the right side in the left-right direction in FIG. 1) facing the imaging device main body (not shown).

  An imaging photoelectric conversion element, that is, an imaging element is arranged in the imaging apparatus main body. The image sensor photoelectrically converts external light incident through the lens barrel 100 and outputs an electrical signal corresponding to the amount of incident light. Specifically, the imaging element can be realized by a solid-state imaging element such as a CCD image sensor (Charge Coupled Device Image Sensor) or a CMOS image sensor (Complementary Metal Oxide Semiconductor).

  A plurality (five in this embodiment) of lens groups 104, 105, 106, 107, and 108 are provided on the inner peripheral side of the lens barrel 101. The plurality of lens groups 104, 105, 106, 107, 108 are arranged in order from the objective side (left side in the left-right direction in FIG. 1), the first lens group 104, the second lens group 105, the third lens group 106, and the fourth lens group. The lens group 107 and the fifth lens group 108 are arranged in this order.

  Of the plurality of lens groups, the first lens group 104 provided on the most object side is constituted by a first lens frame 109 and a first lens 110 held by the first lens frame 109. The first lens 110 may be a single lens or a plurality of lenses.

  The first lens 110 in this embodiment is composed of a plurality of lenses arranged in the optical axis direction. In FIG. 1, the code | symbol C has shown the optical axis. The first lens frame 109 is attached to the objective side of the lens barrel 101 and has a substantially cylindrical shape. The position of the first lens frame 109 with respect to the lens barrel 101 is fixed.

  The second lens group 105, the third lens group 106, the fourth lens group 107, and the fifth lens group 108 are constituted by one lens or a plurality of lenses. The second lens group 105, the third lens group 106, the fourth lens group 107, and the fifth lens group 108 are respectively provided so as to be movable along the optical axis direction relative to the lens barrel 101. . About the structure which can move the 2nd lens group 105, the 3rd lens group 106, the 4th lens group 107, and the 5th lens group 108 along an optical axis direction, it is easily realizable using various well-known techniques. Therefore, the description is omitted.

  In the lens barrel 100, with the first lens group 104 fixed, the second lens group 105, the third lens group 106, the fourth lens group 107, and the fifth lens group 108 are moved to the object side along the optical axis direction. Alternatively, by moving the eyepiece side, it is possible to adjust the focal position with respect to the image sensor provided in the imaging device.

  In the lens barrel 101, an optical filter switching mechanism 120 is provided between the third lens group 106 and the fourth lens group 107. In this embodiment, an optical element switching mechanism can be realized by the optical filter switching mechanism 120. The optical filter switching mechanism 120 includes a plurality of ND (Neutral Density) filters (see FIG. 3), and selectively selects one of the ND filters on the optical path according to the operation of the operator. It can be positioned.

  2, 3 and 4 are explanatory views showing the optical filter switching mechanism 120 according to the embodiment of the present invention. FIG. 2 shows an exploded perspective view from the objective side of the optical filter switching mechanism 120 according to the embodiment of the present invention. FIG. 3 shows a state in which the optical filter switching mechanism 120 according to the embodiment of the present invention is viewed from the objective side. FIG. 4 shows a state in which a part of the optical filter switching mechanism 120 according to the embodiment of the present invention is viewed from the objective side.

  2, 3, and 4, the optical filter switching mechanism 120 according to the embodiment of the present invention includes a holding member 201, a fixed base member 202, and a turntable 203. The holding member 201, the fixed base member 202, and the turntable 203 are arranged in the order of the holding member 201, the fixed base member 202, and the turntable 203 from the objective side along the optical axis direction.

  The position of the fixed base member 202 is fixed with respect to the lens barrel 101. The fixed base member 202 includes an opening 202a penetrating in the optical axis direction so as to open an optical path in the lens barrel 100. The opening 202a has a circular shape, and allows light from a subject (imaging target) incident on the lens barrel 100 to pass to the eyepiece side. The fixed base member 202 is arranged with respect to the lens barrel 101 so that the center of the opening 202a in the fixed base member 202 coincides with the optical axis.

  A rotation restricting portion 202 b is provided at the peripheral edge of the fixed base member 202. The rotation restricting portion 202 b has a rib shape protruding from the fixed base member 202 toward the holding member 201 along the peripheral edge of the fixed base member 202. The rotation restricting portion 202b preferably protrudes from the fixed base member 202 at a thickness equal to or less than the plate thickness of the holding member 201.

  The holding member 201 holds the ND filter 301 (301A, 301B, 301C). The ND filter 301 (301A, 301B, 301C) is provided so as to cover the plurality of openings 201a, 201b, 201c, 201d provided in the holding member 201, respectively.

  Accordingly, the plurality of openings 201a, 201b, 201c, and 201d are positioned at the same position in the optical axis direction, and the plurality of ND filters 301A, 301B, and 301C that cover the plurality of openings 201a, 201b, and 201c are also respectively Positioned at the same position in the axial direction. The plurality of openings 201a, 201b, 201c, and 201d and the plurality of ND filters 301A, 301B, and 301C are positioned at substantially the same position in the optical axis direction.

  The plurality of openings 201a, 201b, 201c, 201d provided in the holding member 201 each penetrate the holding member 201 along the optical axis direction. The ND filter 301 (301A, 301B, 301C) is attached to the holding member 201 so as to cover the plurality of openings 201a, 201b, 201c provided in the holding member 201, respectively.

  In this embodiment, the holding member 201 includes three ND filters 301. In this embodiment, an optical element can be realized by the ND filter 301 (301A, 301B, 301C).

  In the optical filter switching mechanism 120 of this embodiment, the holding member 201 includes four openings 201a, 201b, 201c, and 201d, and the number of ND filters 301 is three. For this reason, one opening 201d among the plurality of openings 201a, 201b, 201c, and 201d is not provided and is open.

  In this embodiment, in addition to the ND filter 301 (301A, 301B, 301C) provided in the openings 201a, 201b, 201c, the ND filter 301 (301A, 301B, 301C) is not provided and is opened. An optical element can also be realized by the opening 201d.

  The number of ND filters 301 provided in the optical filter switching mechanism 120 is not limited to three. The number of ND filters 301 provided in the optical filter switching mechanism 120 may be four or more. For example, by providing ND filters in all of the four openings 201a, 201b, 201c, and 201d, the number of ND filters can be four.

  For example, when the number of ND filters included in the optical filter switching mechanism 120 is five, the shape of the holding member 201 and the fixed base member 202 is a pentagon. In this case, the pentagon formed by the holding member 201 and the pentagon formed by the fixed base member 202 are provided in a state where the arrangement direction is reversed.

  Alternatively, the number of ND filters included in the optical filter switching mechanism 120 may be three or less. For example, when the number of ND filters included in the optical filter switching mechanism 120 is three, the shapes of the holding member 201 and the fixed base member 202 are triangular. In this case, the triangle formed by the holding member 201 and the triangle formed by the fixed base member 202 are provided in a state where the arrangement direction is reversed.

  Further, for example, when the number of ND filters provided in the optical filter switching mechanism 120 is three or less, the number of ND filters provided in the holding member 201 is reduced, and the openings 201a, 201b, 201c, which are opened without being provided with anything. The number of 201d may be increased to two or more.

  The ND filter 301 (301A, 301B, 301C) reduces the amount of light passing through the ND filter 301 (301A, 301B, 301C) with respect to the amount of light incident on the ND filter 301 (301A, 301B, 301C). By using the ND filter 301 (301A, 301B, 301C), it is possible to reduce the shutter speed. For example, when taking a portrait in fine weather when using a large-diameter lens, it is possible to shoot in an open state. You can shoot images with special effects by shooting for a long time by reducing the shutter speed.

  In this embodiment, a plurality of types (three types in this embodiment) of ND filters 301 (301A, 301B, 301C) having different degrees of darkness such as black or silver by metal deposition are attached. Specifically, the ND filter 301 (301A, 301B, 301C) includes, for example, “ND2”, “ND4”, “ND8”, “ND400”, etc. 2. If “ND400”, the light quantity is 1/400. In the optical filter switching mechanism 120, the density of the ND filter 301 held by each holding member 201 is different.

  The openings 201a, 201b, 201c, and 201d provided in the holding member 201 have substantially the same diameter as the opening 202a. The ND filter 301 (301A, 301B, 301C) is held by the holding member 201 so as to cover the openings 201a, 201b, 201c provided in the holding member 201. Specifically, the ND filter 301 (301A, 301B, 301C) is bonded to the holding member 201 with an adhesive, for example.

  The holding member 201 includes a cam pin 204. The cam pin 204 is provided so as to protrude from the eyepiece side surface of the holding member 201 to the eyepiece side along the optical axis direction. The cam pin 204 is inserted into a key groove 203 a provided on the rotating disk 203 via a guide portion 210 provided on the fixed base member 202.

  The guide part 210 includes a first direction cam groove part 210a and a second direction cam groove part 210b. The first direction cam groove portion 210a has a direction substantially parallel to the first direction extending along a plane orthogonal to the optical axis as a longitudinal direction, and penetrates the fixed base member 202 along the optical axis direction. It has a slit shape.

  The second direction cam groove portion 210b extends along a plane orthogonal to the optical axis and is substantially parallel to the second direction orthogonal to the first direction on the plane orthogonal to the optical axis. The direction is a longitudinal direction, and a slit shape penetrating the fixed base member 202 along the optical axis direction is formed.

  The second direction cam groove portion 210b has both ends in the longitudinal direction of the first direction cam groove portion 210a such that the slit formed by the second direction cam groove portion 210b is continuous with the slit shape formed by the first direction cam groove portion 210a. Is provided. Each of the first direction cam groove portion 210a and the second direction cam groove portion 210b has a shape in which the center portion is curved in a direction away from the optical axis. In this embodiment, the first cam groove can be realized by the guide portion 210.

  The turntable 203 is supported so as to be rotatable about the optical axis with respect to the fixed base member 202 (see arrow ar1 in FIG. 2). The turntable 203 is provided so as to be rotatable relative to the fixed base member 202 around the optical axis C. The turntable 203 includes an opening 203b penetrating in the optical axis direction so as to open an optical path in the lens barrel 100. The opening 203b has a circular shape, and allows light from a subject (imaging target) incident on the lens barrel 100 to pass to the eyepiece side.

  The turntable 203 is arranged with respect to the lens barrel 101 so that the center of the opening 203b in the turntable 203 coincides with the optical axis. Thereby, the opening 203b in the turntable 203 overlaps with the opening 202a of the fixed base member 202 in the optical axis direction. The opening diameter of the opening 203 b in the turntable 203 is larger than the opening diameter of the opening 202 a of the fixed base member 202. In this embodiment, a rotating member can be realized by the turntable 203.

  The turntable 203 includes gear teeth not shown. The gear teeth are meshed with the transmission gear 205 via a transmission gear (see reference numeral 901 in FIG. 9) provided in the vicinity of the rotating disk 203. The transmission gear 205 is connected to the transmission gear 206. The transmission gear 205 is provided so as to be rotatable in a plane orthogonal to the optical axis with a rotation axis (not shown) parallel to the optical axis as a rotation center (arrow in FIG. 2). see ar2). The transmission gear 206 is provided so as to be rotatable in a plane orthogonal to the optical axis with a rotation axis (not shown) parallel to the optical axis as a rotation center (arrow in FIG. 2). see ar3).

  A switching lever 207 is connected to the transmission gear 206. The switching lever 207 is provided so as to be rotatable within a plane orthogonal to the optical axis with a rotation shaft 207a parallel to the optical axis as a rotation center (see arrow ar4 in FIG. 2). Thus, when the switching lever 207 is rotated about the rotation shaft 207 a as the rotation center, the transmission gear 205 can be rotated via the transmission gear 206. Since the transmission gear 205 is connected to the rotating disk 203, the rotating disk 203 can be rotated by rotating the switching lever 207.

  In this embodiment, the transmission gear 205 and the switching lever 207 connected to the rotating disk 203 are connected via the transmission gear 206. However, the present invention is not limited to this. The transmission gear 205 and the switching lever 207 may be directly connected. Alternatively, the transmission gear 205 and the switching lever 207 may be coupled via, for example, two or more transmission gears.

  The key groove 203 a provided on the rotary disk 203 is fitted with the tip of the cam pin 204 protruding to the eyepiece side of the fixed base member 202 by penetrating the guide portion 210. The key groove 203a holds the cam pin 204 fitted in the key groove 203a. In this embodiment, the second cam groove can be realized by the key groove 203a.

  By holding the cam pin 204 by the key groove 203 a, the rotational force of the rotating disk 203 due to the rotation of the rotating disk 203 can be transmitted to the cam pin 204. By transmitting the rotational force of the rotating disk 203 to the cam pin 204, the holding member 201 can be moved in a plane perpendicular to the optical axis via the cam pin 204.

  The position of the fixed base member 202 is fixed with respect to the lens barrel 101, and the cam pin 204 is inserted into a guide portion 210 provided on the fixed base member 202. For this reason, when the turntable 203 rotates, the cam pin 204 moves along the guide part 210 in the guide part 210. The holding member 201 moves as the cam pin 204 moves. That is, the holding member 201 substantially translates along a plane orthogonal to the optical axis as the turntable 203 rotates with respect to the fixed base member 202.

  As the cam pin 204 moves, the holding member 201 moves in a state where a part of the outer peripheral edge is in contact with the rotation restricting portion 202b. The holding member 201 brings one side of the outer peripheral edge into contact with the rotation restricting portion 202b in a state where one of the four openings 201a, 201b, 201c, and 201d overlaps the opening 202a.

  As a result, the holding member 201 can be prevented from rotating around the cam pin 204. Then, by preventing the holding member 201 from rotating around the cam pin 204, the opening 201a, 201b, 201c or 201d positioned at the position overlapping the opening 202a is stably positioned at the position with respect to the opening 202a. be able to.

  Regardless of the position of the ND filter 301 (301A, 301B, 301C) and the opening 201d with respect to the optical path, the rotation restricting portion 202b prevents the holding member 201 from protruding beyond the outer diameter of the lens barrel 101. It contacts the outer peripheral edge of the holding member 201. Thereby, the size of the lens barrel 100 in the plane orthogonal to the optical axis is determined depending on the diameter of the lens barrel 100 without being influenced by the size of the optical filter switching mechanism 120.

  The first direction cam groove portion 210 a and the second direction cam groove portion 210 b described above rotate a part of the outer peripheral edge of the holding member 201 when the cam pin 204 moves in the guide portion 210 along the guide portion 210. It is curved so that it can be brought into contact with the restricting portion 202b. The rotation restricting portion 202b has a closed loop shape so that a part of the holding member 201 always comes into contact with the rotation restricting portion 202b when the cam pin 204 moves along the guide portion 210 in the guide portion 210. There is no.

  Accordingly, it is possible to prevent the holding member 201 from rotating around the cam pin 204 when the cam pin 204 moves along the guide portion 210 in the guide portion 210. And thereby, desired opening 201a, 201b, 201c or 201d can be overlapped with the opening 202a.

  Next, the operation of the optical filter switching mechanism 120 according to the embodiment of the present invention will be described. 5, 6, 7 and 8 are explanatory views showing respective states that can be taken by the optical filter switching mechanism 120 according to the embodiment of the present invention. 5, 6, 7, and 8 show the optical filter switching mechanism 120 according to the embodiment of the present invention as viewed from the objective side in the optical axis direction.

  5, 6, 7, and 8, the optical filter switching mechanism 120 according to the embodiment of the present invention includes a first state (see FIG. 5), a second state (see FIG. 6), Various states of the third state (see FIG. 7) and the fourth state (see FIG. 8) can be taken.

  In the first state, the opening 201d is positioned at a position overlapping the opening 202a. In the first state, the three ND filters 301 (301A, 301B, 301C) are all positioned at positions retracted from the optical path.

  In the second state, the opening 201a is positioned at a position overlapping the opening 202a. That is, in the second state, the ND filter 301A is positioned at a position overlapping the opening 202a, and the opening 202a is covered with the ND filter 301A. In the second state, among the three ND filters 301, the ND filters 301B and 301C other than the ND filter 301A and the opening 201d are positioned at positions where they are retracted from the optical path.

  In the third state, the opening 201b is positioned at a position overlapping the opening 202a. That is, in the third state, the ND filter 301B is positioned at a position overlapping the opening 202a, and the opening 202a is covered with the ND filter 301B. In the third state, among the three ND filters 301, the ND filters 301A and 301C other than the ND filter 301B and the opening 201d are positioned at positions retracted from the optical path.

  In the fourth state, the opening 201c is positioned so as to overlap the opening 202a. That is, in the fourth state, the ND filter 301C is positioned at a position overlapping the opening 202a, and the opening 202a is covered with the ND filter 301C. Further, in the fourth state, of the three ND filters 301, the ND filters 301A and 301B other than the ND filter 301C and the opening 201d are positioned at positions where they are retracted from the optical path.

  When shifting from the first state to the second state, first, the switch lever 207 is operated in the state of FIG. Thereby, the cam pin 204 moves along the guide portion 210 in the second direction cam groove portion 210b of the guide portion 210 in a direction approaching the first direction cam groove portion 210a.

  The holding member 201 moves downward in FIG. 5 with the movement of the cam pin 204 in the guide portion 210. While the holding member 201 is moving with the movement of the cam pin 204 in the guide portion 210, at least a part of the outer peripheral edge of the holding member 201 is in contact with the rotation restricting portion 202b.

  Accordingly, the rotation of the holding member 201 around the cam pin 204 is restricted during the movement of the holding member 201 with the movement of the cam pin 204 in the guide portion 210. As described above, in the optical filter switching mechanism 120, when the first state (ie, the state shown in FIG. 5) shifts to the second state (ie, the state shown in FIG. 6), the holding to the fixed base member 202 is performed. The position of the member 201 changes.

  When shifting from the second state to the third state, first, the switch lever 207 is operated in the state of FIG. As a result, the cam pin 204 moves away from the second direction cam groove portion 210b on one side (the right side in FIG. 6) in the first direction cam groove portion 210a in the guide portion 210 along the guide portion 210, and on the other side (FIG. 6 in the direction closer to the second direction cam groove portion 210b.

  The holding member 201 moves from the right side to the left side in FIG. 6 with the movement of the cam pin 204 in the guide portion 210. While the holding member 201 is moving with the movement of the cam pin 204 in the guide portion 210, at least a part of the outer peripheral edge of the holding member 201 is in contact with the rotation restricting portion 202b.

  Accordingly, the rotation of the holding member 201 around the cam pin 204 is restricted during the movement of the holding member 201 with the movement of the cam pin 204 in the guide portion 210. As described above, in the optical filter switching mechanism 120, when shifting from the second state (ie, the state shown in FIG. 6) to the third state (ie, the state shown in FIG. 7), the holding to the fixed base member 202 is performed. The position of the member 201 changes.

  When shifting from the third state to the fourth state, first, the switch lever 207 is operated in the state of FIG. As a result, the cam pin 204 moves along the guide portion 210 in the other second direction cam groove portion 210b of the guide portion 210 in a direction away from the first direction cam groove portion 210a.

  The holding member 201 moves from the lower side to the upper side in FIG. 7 with the movement of the cam pin 204 in the guide portion 210. While the holding member 201 is moving with the movement of the cam pin 204 in the guide portion 210, at least a part of the outer peripheral edge of the holding member 201 is in contact with the rotation restricting portion 202b.

  Accordingly, the rotation of the holding member 201 around the cam pin 204 is restricted during the movement of the holding member 201 with the movement of the cam pin 204 in the guide portion 210. As described above, in the optical filter switching mechanism 120, when the third state (ie, the state shown in FIG. 7) shifts to the fourth state (ie, the state shown in FIG. 8), the holding to the fixed base member 202 is performed. The position of the member 201 changes.

  As shown in FIGS. 5, 6, 7, and 8, the switching lever 207 has the first state → the second state, the second state → the third state, the third state → the fourth state. When the state, the fourth state → the third state, the third state → the second state, the second state → the first state, the state is rotated by a certain angle. The turntable 203 rotates by a predetermined angle with respect to the fixed base member 202 every time the switching lever 207 rotates by a certain angle.

  In this way, the holding member 201 has an optical axis so that the cam pin 204 is moved to a predetermined position in the guide portion 210 as the rotating disk 203 rotates by a predetermined angle with respect to the fixed base member 202. It translates substantially along a plane perpendicular to it. In the optical filter switching mechanism 120, when the cam pin 204 is positioned at a predetermined position in the guide unit 210, any one of the ND filters 301 (301A, 301B, 301C) and the opening 201d is selected. (301A, 301B or 301C) or the position of the ND filter 301 (301A, 301B, 301C) and the opening 201d with respect to the opening 202a is switched so that the opening 201d overlaps the opening 202a in the optical axis direction. Here, a guide mechanism is realized by the holding member 201, the fixed base member 202, the rotating disk 203, the transmission gears 205 and 206, and the switching lever 207.

  That is, in this guide mechanism, when the turntable 203 is rotated by a predetermined angle, the holding member 201 is substantially translated by moving the cam pin 204 to a predetermined position in the guide portion 210 via the key groove 203a. By doing so, the ND filter 301 (301A, 301B, 301C) so that any one of the plurality of ND filters 301 (301A, 301B, 301C) or the opening 201d overlaps the opening 202a in the optical axis direction. And the opening 201d can be switched. The rotation restricting portion 202b described above restricts the rotation of the holding member 201 by contacting the holding member 201 when the cam pin 204 is moved to a predetermined position in the guide portion 210.

  Next, the configuration of the optical filter switching mechanism 120 according to the embodiment of the present invention will be described in detail. 9, FIG. 10 and FIG. 11 are explanatory views showing the positional relationship of each part provided in the optical filter switching mechanism 120 according to the embodiment of the present invention. In FIG. 9, the positional relationship of each part with which the said optical filter switching mechanism 120 is provided when the optical filter switching mechanism 120 of embodiment concerning this invention is seen along an optical axis direction is shown. In FIG. 10, the AA cross section of FIG. 9 is shown. In FIG. 11, the positional relationship of each part with which the said optical filter switching mechanism 120 is provided when the optical filter switching mechanism 120 of embodiment concerning this invention is seen from the direction orthogonal to an optical axis is shown.

  9, 10 and 11, the switching lever 207 provided in the optical filter switching mechanism 120 according to the embodiment of the present invention is in the first position centering on the rotation shaft 207 a (see reference sign pos <b> 1 in FIG. 9). To the fourth position (see symbol pos4 in FIG. 9). When the switching lever 207 rotates about the rotation shaft 207a, the first position, the second position (see the sign pos2 in FIG. 9), the third position (see the sign pos3 in FIG. 9), and the fourth position. It is possible to stop at.

  The switching lever 207 is positioned at the first position when the optical filter switching mechanism 120 is in the first state. The switching lever 207 is positioned at the second position when the optical filter switching mechanism 120 is in the second state. The switching lever 207 is positioned at the third position when the optical filter switching mechanism 120 is in the third state. The switching lever 207 is positioned at the fourth position when the optical filter switching mechanism 120 is in the fourth state.

  The transmission gear 205, the transmission gear 206, and the switching lever 207 are arranged in the order of the transmission gear 205, the transmission gear 206, and the switching lever 207 from the subject side along the optical axis direction. The holding member 201, the fixed base member 202, and the turntable 203 are provided on the subject side with respect to the transmission gear 205.

  The rotating disk 203 is urged in a direction in contact with the transmission gear 901 by a torsion spring 911 on a plane orthogonal to the optical axis. One end of the torsion spring 911 is in contact with the turntable 203 and the other end is in contact with the rotation restricting portion 210 from the optical axis side. The torsion spring 911 is provided on the fixed base member 202 in a compressed state so that one end and the other end of the torsion spring 911 approach each other so as to apply a biasing force in the opening direction.

  The turntable 203 includes an engagement receiving portion 203b for coming into contact with the torsion spring 911 on the outer peripheral side in the radial direction of a substantially disk centered on the optical axis. The locking receiving portion 203b (203b1, 203b2, 203b3, 203b4) has a concave shape toward the optical axis C, and is arranged in four equal parts on the outer peripheral side in the radial direction of the rotating disk 203. When the turntable 203 is rotated by a predetermined angle, that is, when the optical filter switching mechanism 120 is positioned at the first position, the second position, the third position, or the fourth position, the latch receiving portion 203b (203b1, 203b2, 203b3, 203b4) is in contact with one end of the torsion spring 911, and the other end of the torsion spring 911 is fixed to the fixed base member 202. , Is firmly locked. Therefore, when the optical filter switching mechanism 120 is positioned at the first position, the second position, the third position, or the fourth position, the ND filter 301 (301A, 301B, 301C) with respect to the opening 202a. In addition, the position of the opening 201d can be stabilized.

  Next, the operation of the optical filter switching mechanism 120 according to the embodiment of the present invention will be described in detail. 12, FIG. 13, FIG. 14, FIG. 16, FIG. 17, FIG. 18 and FIG. 18 are explanatory views showing the positional relationship of each part in each state that can be taken by the optical filter switching mechanism 120 according to the embodiment of the present invention. It is. 12, FIG. 13, FIG. 14, FIG. 15, FIG. 17, FIG. 17 and FIG. 18 show the optical filter switching mechanism 120 according to the embodiment of the present invention as viewed from the objective side in the optical axis direction. Yes.

  12, FIG. 13, FIG. 14, FIG. 16, FIG. 17, and FIG. 18, the optical filter switching mechanism 120 according to the embodiment of the present invention is changed from the first state (see FIG. 12) to the first state. The state changes to the second state (see FIG. 14) via the state of 1.5 (see FIG. 13). Further, the optical filter switching mechanism 120 changes from the second state to the third state via the 2.5th state (see FIG. 15). Furthermore, the optical filter switching mechanism 120 changes from the third state to the fourth state via the 3.5th state (see FIG. 17).

  As shown in FIGS. 12, 13, 14, 15, 16, 17, and 18, when the cam pin 204 moves in the guide portion 210 as the switching lever 207 rotates, the cam pin in the key groove 203a. The position of 204 changes. The cam pin 204 is positioned at one end of the key groove 203a in the first state, the second state, the third state, and the fourth state.

  The cam pin 204 is located at the other end of the key groove 203a in the 1.5th state, the 2.5th state, the 3.5th state, and the 4.5th state. Each time the state of the optical filter switching mechanism 120 changes by one state, such as the first state → the second state, the second state → the third state, and the third state → the fourth state, the cam pin 204 changes. Then, it moves so as to reciprocate between one end and the other end of the key groove 203a.

  When the optical filter switching mechanism 120 is in the first state, the second state, the third state, and the fourth state, the cam pin 204 is positioned at one end of the key groove 203a. At this time, the cam pin 204 is pressed against the outer peripheral wall of the circle centering on the optical axis in the guide portion 210. Accordingly, the positions of the ND filter 301 (301A, 301B, 301C) and the opening 201d with respect to the opening 202a can be stabilized in the first state, the second state, the third state, and the fourth state. .

  As described above, the optical filter switching mechanism 120 (optical element switching mechanism) according to the embodiment of the present invention is provided with respect to the fixed base member 202 including the opening 202a that allows the light of the subject to pass therethrough, and the fixed base member 202. The rotating disk 203 as an example of a rotating member supported so as to be rotatable around the optical axis and the ND filters 301 (301A, 301B, 301C) as an example of a plurality of optical elements are held on substantially the same plane. With the rotation of the rotating disk 203 with respect to one holding member 201 and the fixed base member 202, the holding member 201 is substantially translated along a plane orthogonal to the optical axis, whereby a plurality of ND filters 301 ( 301A, 301B, 301C) or one of the openings 201d is moved to a position where it overlaps with the opening 202a. ND filters 301 (301A, 301B301C) is characterized by performing the switching of and openings 201d.

  According to the optical filter switching mechanism 120 of the embodiment of the present invention, the plurality of ND filters 301 (301A, 301B, 301C) and the opening 201d are positioned at the same position in the optical axis direction, and the position of the ND filter 301 with respect to the optical path Regardless of the configuration, all the ND filters 301 (301A, 301B, 301C) and the holding member 201 are configured so as not to protrude beyond the outer diameter of the lens barrel 101. While suppressing an increase in size of the cylinder 101, a desired optical element among the plurality of optical elements can be selectively positioned on the optical path.

  The optical filter switching mechanism 120 according to the embodiment of the present invention includes a holding mechanism 201, a guide mechanism realized by the holding member 201, the fixed base member 202, the rotating disk 203, the transmission gears 205 and 206, and the switching lever 207. A cam pin 204 provided on the fixed base member 202, a guide portion 210 as an example of a first cam groove on which the cam pin 204 is fitted, and a second on which the cam pin 204 is fitted on the rotating disk 203. And a key groove 203a as an example of the cam groove, and the guide portion 210 has a first direction having a longitudinal direction that is substantially parallel to a first direction extending along a plane orthogonal to the optical axis. The cam groove portion 210a and a second direction cam groove portion 2 extending along the plane and having a direction substantially parallel to a second direction orthogonal to the first direction as a longitudinal direction. 0b, and the key groove 203a holds the fitted cam pin 204 and transmits the rotational force of the rotating disk 203 to the cam pin 204, and the rotating disk 203 is rotated at a predetermined angle. By moving the holding member 201 substantially in translation by moving the cam pin 204 to a predetermined position in the guide portion 210 via the key groove 203a, among the plurality of ND filters 301 (301A, 301B, 301C) and the openings 201d The ND filter 301 (301A, 301B, 301C) and the opening 201d are switched so that any one of them moves to a position overlapping with the opening 202a.

  According to the optical filter switching mechanism 120 of this embodiment, a plurality of ND filters 301 (301A, 301B, 301C) are suppressed with a small number of parts while suppressing an increase in the size of the lens barrel 101 in the outer diameter direction and the optical axis direction. The desired ND filter 301A, 301B, 301C or the opening 201d in the opening 201d can be selectively positioned on the optical path.

  Further, the optical filter switching mechanism 120 according to the embodiment of the present invention is configured such that the fixed base member 202 abuts on the holding member 201 when the cam pin 204 is moved to a predetermined position in the guide portion 210. A rotation restricting portion 202b for restricting the rotation of 201 is provided.

  According to the optical filter switching mechanism 120 of this embodiment, the holding member 201 is maintained in a desired posture when switching the positions of the ND filter 301 (301A, 301B, 301C) and the opening 201d without increasing the number of components. At the same time, the rotation of the holding member 201 positioned in each of the first to fourth states can be restricted.

  The optical filter switching mechanism 120 according to the embodiment of the present invention includes a locking receiving portion 203b provided on the outer peripheral side of the turntable 203 and a light when the turntable 203 is turned at a predetermined angle. The rotating plate 203 is engaged by abutment with a torsion spring 911 which is provided along a direction orthogonal to the axis, one end is fixed to the fixed base member 202 and the other end is biased toward the optical axis. It is characterized by being stopped.

  According to the optical filter switching mechanism 120 of this embodiment, in the first state, the second state, the third state, and the fourth state, the ND filter 301 (301A, 301B, 301C) for the opening 202a and The position of the opening 201d can be stabilized.

  Further, the optical filter switching mechanism 120 according to the embodiment of the present invention realizes the optical element by the ND filter 301 (301A, 301B, 301C) and the opening 201d, so that the lens barrel 101 in the outer diameter direction and the optical axis direction is realized. The desired one of the plurality of ND filters 301 (301A, 301B, 301C) and the opening 201d can be selectively positioned on the optical path while suppressing the increase in the size of the filter, thereby realizing a multi-stage density switching. can do.

(Another embodiment)
The optical filter switching mechanism according to the present invention is not limited to the optical filter switching mechanism 120 in the above-described embodiment. The optical filter switching mechanism according to the present invention may have the following configuration.

  19, FIG. 20, FIG. 21, FIG. 22, FIG. 23, and FIG. 24 are explanatory views showing an optical filter switching mechanism according to another embodiment of the present invention. FIG. 19 shows a perspective state of the optical filter switching mechanism according to another embodiment of the present invention from the objective side. FIG. 20 shows a perspective state from the eyepiece side of an optical filter switching mechanism according to another embodiment of the present invention. FIG. 21 shows an exploded perspective view from the objective side of an optical filter switching mechanism according to another embodiment of the present invention. In FIG. 22, the state which looked at the optical filter switching mechanism of another embodiment concerning this invention from the objective side is shown. In FIG. 23, the state which looked at the optical filter switching mechanism 120 of embodiment concerning this invention from the side is shown. In FIG. 24, the BB cross section in FIG. 22 is shown.

  19, 20, 21, 22, 23, and 24, an optical filter switching mechanism 1900 according to another embodiment of the present invention includes a shaft member 2101. The shaft member 2101 includes a base portion 2101a and a cylindrical portion 2101b. The base portion 2101a has a substantially square outer periphery. The base portion 2101a includes an opening 2101c that penetrates in the optical axis direction so as to open the optical path in the lens barrel 100.

  The turntable 203 is supported by the cylindrical portion 2101b so as to be rotatable around the optical axis by being inserted into the cylindrical portion 2101b along the optical axis direction. The cylindrical portion 2101b is inserted into the opening 1901a of the rear cover 1901 along the optical axis direction, and is fixed to the rear cover 1901 using an adhesive or the like. The turntable 203 does not move in the optical axis direction, and is disposed so as to be rotatable around the optical axis between the base portion 2101a of the shaft member 2101 and the rear cover 1901. A motor 2001 is provided on the eyepiece side of the rear cover 1901.

  The base portion 2101 a of the shaft member 2101 enters a notch 2102 formed in the fixed base member 1902 when the rear cover 1901 is attached to the fixed base member 1902. The notch 2102 is formed at the center position of the fixed base member 1902 and has a substantially square shape.

  The cutout portion 2102 has a substantially square shape that is slightly larger than the substantially square shape formed by the outer periphery of the base portion 2101a. The base portion 2101a and the fixed base member 1902 are disposed on the same plane substantially orthogonal to the optical axis. Since the outer periphery of the base portion 2101a has a substantially square shape and is slightly smaller than the substantially square shape of the notch portion 2102, the guide portion 2201 (first cam groove) is formed by the outer periphery of the notch portion 2102 and the base portion 2101a. ) Is formed in a slit shape having a substantially square shape.

  FIG. 25 is an explanatory view showing the shape of the guide part 2201. In FIG. 25, the guide part 2201 is connected to one round. As described above, since the guide unit 2201 is connected in a circle, the filter switching mechanism 1900 rotates when the driving force is supplied to the filter switching mechanism 1900 via the transmission gears 205 and 206 using the motor 2001. By rotating the panel 203 only in one direction (clockwise or counterclockwise), a desired ND filter 301A, 301B, 301C or the opening among the plurality of ND filters 301 (301A, 301B, 301C) and the opening 201d or the opening 201d can be selectively positioned on the optical path. Therefore, the operability of the optical filter switching mechanism 1900 can be improved.

  In the configuration of the above-described embodiment, since the first cam groove does not extend all around, the switching in the optical filter switching mechanism 120 must be rotated clockwise and then returned counterclockwise. On the other hand, in the filter switching mechanism 1900 of another embodiment, a plurality of ND filters 301 (301A, 301B, 301C) can be obtained by rotating the rotating member only in one direction (clockwise or counterclockwise). And the switching operation of the opening 201d can be realized.

  Further, in the optical filter switching mechanism 1900 according to the embodiment of the present invention, the fixed base member 1902 is provided with a substantially square cutout portion 2102, provided inside the cutout portion 2102, while supporting the turntable 203. A shaft member 2101 having a second opening 2101c having an inner circumference that allows the light of the subject to pass therethrough, and an outer circumference having a substantially square shape. The holding member 201, the fixed base member 202, the shaft member 2101, the turntable 203, and the transmission An example of a first cam groove in which a guide mechanism realized by the gears 205 and 206 and the motor 2001 is formed by a cam pin 204 provided in the holding member 201 and a notch 2102 and a shaft member 2101 and the cam pin 204 is fitted therein. As a guide part 2201 and a second cam groove provided on the rotating disk 203 and fitted with a cam pin 204. And the key groove 203a holds the fitted cam pin 204 and transmits the rotational force of the rotating disk 203 to the cam pin 204, and the rotating disk 203 is rotated at a predetermined angle. Further, by moving the holding member 201 substantially in translation by moving the cam pin 204 to a predetermined position in the guide portion 210 via the key groove 203a, the plurality of ND filters 301 (301A, 301B, 301C) and the openings 201d are formed. The ND filter 301 (301A, 301B, 301C) and the opening 201d are switched so that any one of them moves to a position overlapping the opening 2101c.

  According to the optical filter switching mechanism 1900 of this embodiment, the motor 2001 is rotated clockwise or counterclockwise with a small number of parts while suppressing the enlargement of the lens barrel 101 in the outer diameter direction and the optical axis direction. By rotating only in the direction, a desired ND filter 301A, 301B, 301C or opening 201d among the plurality of ND filters 301 (301A, 301B, 301C) and the opening 201d can be selectively positioned on the optical path. . Therefore, the operability of the optical filter switching mechanism 1900 can be improved.

  In the optical filter switching mechanisms 120 and 1900 of this embodiment, the optical element is realized by the ND filter 301, but the optical element is not limited to that realized by the ND filter 301. Specifically, for example, instead of the ND filter 301, an infrared cut filter or the like for removing infrared rays in outside light may be used as the optical element.

  The lens barrel 100 according to the embodiment of the present invention is characterized by including the optical filter switching mechanisms 120 and 1900 described above. According to the lens barrel 100 of the embodiment of the present invention, the lens barrel 100 can be downsized.

  As described above, the optical element switching mechanism according to the present invention includes a plurality of optical elements such as a plurality of ND filters having different densities, for example, and selectively selects a desired optical element among the plurality of optical elements. It is useful for an optical element switching mechanism that switches an optical element positioned in an optical path as appropriate, and is particularly suitable for an optical element switching mechanism that requires a reduction in thickness.

DESCRIPTION OF SYMBOLS 100 Lens barrel 101 Lens barrel 120 Optical filter switching mechanism 201 Holding member 202 Fixed base member 202a Opening portion 202b Rotation restricting portion 203 Rotary disc 204 Cam pin 210 Guide portion 210a First direction cam groove portion 210b Second direction cam groove portion

Claims (7)

A fixed base member having an opening through which the light of the subject passes;
A rotating member supported to be rotatable about an optical axis with respect to the fixed base member;
One holding member for holding a plurality of optical elements on substantially the same plane;
Along with the rotation of the rotation member with respect to the fixed base member, the holding member is substantially translated along a plane orthogonal to the optical axis, whereby any one of the plurality of optical elements is A guide mechanism for switching the optical element so that the optical element moves to a position overlapping the opening;
An optical element switching mechanism comprising: The guide mechanism includes a cam pin provided on the holding member, a first cam groove provided on the fixed base member and fitted with the cam pin, and a first cam groove fitted on the rotating member and fitted with the cam pin. Two cam grooves,
The first cam groove extends along the plane and has a first direction cam groove portion whose longitudinal direction is substantially parallel to the first direction extending along the plane, and the first cam groove. A second direction cam groove having a direction substantially parallel to the second direction orthogonal to the direction of
The second cam groove holds the fitted cam pin and transmits the rotational force of the rotating member to the cam pin.
When the turning member is turned by a predetermined angle, the holding member is moved substantially in translation by moving the cam pin to a predetermined position in the first cam groove via the second cam groove. The optical element according to claim 1, wherein the optical element is switched such that any one of the plurality of optical elements moves to a position overlapping the opening. Element switching mechanism. The fixed base member includes a substantially square notch,
A shaft member provided on the inner side of the notch, having a second opening with an inner circumference passing through the subject's light while supporting the rotating member, and an outer circumference having a substantially square shape;
The guide mechanism includes a cam pin provided on the holding member, a first cam groove formed by the notch portion and the shaft member and fitted with the cam pin, and provided on the rotating member and fitted with the cam pin. A second cam groove to be joined,
The second cam groove holds the fitted cam pin and transmits the rotational force of the rotating member to the cam pin.
When the turning member is turned by a predetermined angle, the holding member is moved substantially in translation by moving the cam pin to a predetermined position in the first cam groove via the second cam groove. The optical element according to claim 1, wherein the optical element is switched such that any one of the plurality of optical elements moves to a position overlapping the opening. Element switching mechanism.   The fixed base member includes a rotation restricting portion that restricts the rotation of the holding member by contacting the holding member when the cam pin is moved to the predetermined position in the first cam groove. The optical element switching mechanism according to any one of claims 1 to 3.   When the rotating member is rotated at the predetermined angle, a locking receiving portion provided on the outer peripheral side of the rotating member and a direction orthogonal to the optical axis are provided, and one end portion is provided on the base The rotating member is locked by being brought into contact with a biasing member that is fixed to the member and whose other end is biased toward the optical axis. The optical element switching mechanism according to one.   The optical element switching mechanism according to claim 1, wherein the optical element is a filter.   A lens barrel comprising the optical element switching mechanism according to claim 1.

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