JP5513961B2 - Lens frame moving mechanism and lens holder - Google Patents

Description

  The present invention relates to a moving mechanism for moving a lens frame in a direction perpendicular to an optical axis, and a lens holder having the moving mechanism.

  In fields such as imaging devices and projection devices, further miniaturization of the entire device is progressing. Along with this, a lens holder (lens barrel) is also required that can store a lens in a narrower space when stored (not used).

  In Patent Document 1, a first lens frame that holds a first lens group, a shutter unit that is disposed on the inner rear side of the first lens frame, has an exposure opening, and is disposed on an inner rear side of the shutter unit. A lens barrel driving mechanism is disclosed that includes a second lens frame that holds a lens group, and a driving unit that extends and retracts the first lens frame and the shutter unit in the optical axis direction.

  In this lens barrel driving mechanism, the side wall portions at both ends of the outer periphery of the second lens frame are respectively extended vertically, and between the position where the second lens frame is disposed in the optical path and the position where the second lens frame is retracted outside the optical path. A pair of guide shafts that are movably supported are provided. Moreover, the side wall part in the outer peripheral edge part of a 2nd lens frame is provided with the axial part which protrudes in the radial direction centering on an optical axis direction. This lens barrel drive mechanism is further moved from the position where the second lens frame is disposed in the optical path along the guide axis to the position where it is retracted outside the optical path along with the retraction operation. A second lens frame moving means for moving is provided.

Japanese Patent Laying-Open No. 2005-189516 (paragraph number 0005)

  In the lens barrel drive mechanism described in Patent Document 1, when in use, the first lens group and the second lens group are arranged side by side in the optical path along the optical axis and stored (when not in use) ), The second lens frame is retracted out of the optical path. By adopting this lens barrel drive mechanism in the lens barrel, the second lens frame can be stored in a state of being retracted out of the optical path. For this reason, the body which becomes the base of the lens barrel can be made thinner (the length of the lens barrel when not in use can be shortened). Furthermore, in the lens barrel drive mechanism described in Patent Document 1, the second lens frame moves while its both ends are supported by a pair of guide shafts. For this reason, the second lens frame can be moved in a stable state.

  By the way, in a lens barrel (lens holder) employing a mechanism as described in Patent Document 1, when the second lens frame is retracted, the second lens frame interferes (contacts or is pressed) with a cylindrical member or the like. That is not very desirable. If the lens barrel drive mechanism tries to move the second lens frame while the second lens frame is in contact with any member, unexpected stress may be applied to various members, which may cause distortion of the member or lens. Because there is sex. Accordingly, the entire lens barrel (lens holder) is designed so that a certain amount of clearance is provided between the second lens frame so as not to interfere with the cylindrical member or the like at the retracted position (storage position). However, in recent years, it has become important to reduce the size of the lens holder, and it is desired to review the necessity of the clearance as described above.

One embodiment of the present invention is a moving mechanism that moves a first lens frame that supports at least one lens in a first direction that is inclined with respect to the optical axis, for example, in a vertical direction. The moving mechanism has a first guide and a second guide extending in the first direction. The first lens frame includes a first slider and a second slider that slide in contact with the first guide and the second guide, respectively, and a first position where at least one lens is set as the optical axis. When at least one lens is separated from the optical axis, to move to the second position Ru position der to retract the first lens frame when not in use. The moving mechanism further includes a first stopper for stopping the first lens frame at the first position, a second stopper for stopping the first lens frame at the second position, and a first slider. A third slider that moves along a first guide between a first passive part on the first position side and a second passive part on the second position side of the first slider; And an elastic member disposed between the third slider and the second passive portion, and a drive mechanism for driving (sliding) the third slider.

  According to this moving mechanism, the first lens frame can be moved to the second position away from the optical axis, and the second position can be used for retracting or storing the lens frame. The second position may be used for other purposes. The moving mechanism slides a third slider that moves (slides) between the first passive portion and the second passive portion of the first slider along the first guide, and the third slider By acting on the first passive part or the second passive part, the first lens frame moves. Further, when the third slider acts on the second passive portion, the second passive portion is pushed toward the second position via the elastic member disposed therebetween. Therefore, even if the third slider is slid to the second position side with the first lens frame hitting (interfering with) the second stopper that defines the second position, The displacement is absorbed by the elastic member, and generation of a large load (stress) in a portion including the first lens frame and the second stopper, for example, the housing of the lens holder can be suppressed.

  Therefore, the first lens frame can be stopped by hitting the second stopper, and the accuracy of the position when the first lens frame stops at the second position away from the optical axis can be improved. Accordingly, the clearance caused by the movement of the first lens frame between the first lens frame and the housing at the second position (retracted position, storage position) of the housing (cylinder member) of the lens holder is provided. There is no need to provide it. For this reason, the space in the lens holder can be more effectively utilized, and for example, the lens holder can be further downsized.

  Even if there is some tolerance in the stroke of the third slider, the second position of the first lens frame can be accurately controlled by the second stopper. It is possible to allow some tolerance in a drive mechanism that is often a combination of a gear, a cam, and the like, and it is possible to provide a moving mechanism with low cost and good positional accuracy.

  In this moving mechanism, it is preferable that the third slider and / or the first passive portion include an abutting portion that contacts the first guide on the side of the second guide. That is, it is preferable that the third slider and / or the first passive portion include a contact portion on the optical axis side with respect to the central axis of the first guide. The first lens frame moves in a posture supported by two points by the first guide and the second guide. At this time, rather than driving the first lens frame by applying a force from the outside of the first guide or the second guide, a force is applied from between (inside) the first guide and the second guide. The driven lens can move the first lens frame without tilting with respect to the first guide and the second guide. Therefore, at the first position, the optical axis of the lens group held by the first lens frame and the optical axis of the lens system can be more accurately aligned.

  However, it is difficult to drive the first slider inside the first guide because the drive mechanism and the first lens frame interfere with each other. On the other hand, by providing the third slider, the third slider is driven outside the first guide, and the third slider and the first slider are applied inside the first guide. The first guide can be driven inside the first guide substantially in the vicinity of the first position. For this reason, the first stopper can hold the first lens frame in a more stable posture while suppressing the tilt of the first lens frame at the first position.

  In this moving mechanism, an example of the elastic member is a coil spring. At this time, it is preferable that the third slider includes a recess into which a part of the coil spring enters on the second guide side. Thereby, an elastic member can be stably arrange | positioned in a predetermined position.

  Another aspect of the present invention is the above-described moving mechanism, a first lens frame that is moved by the moving mechanism, and a second lens frame that supports at least one lens along the optical axis. And a second lens frame whose relative distance to the first lens frame changes. In this lens holder, typically, the first position is a position where at least one lens supported by the first lens frame and at least one lens supported by the second lens frame are used. The second position is a position where the first lens frame is retracted when not in use.

  According to still another aspect of the present invention, the lens holder, at least one lens supported by the first lens frame, and at least one lens supported by the second lens frame are provided. A lens system. In this lens system, when the lens supported by the first lens frame is not used, the lens system can be made compact. On the other hand, when the lens supported by the first lens frame is used, the lens system is optical. It can be set at a precise position. Therefore, it is possible to provide a compact device with good optical performance such as a camera and a projector.

  Still another aspect of the present invention is an image pickup apparatus (camera) including the lens system and an image pickup device that picks up an image formed by the lens system. In this camera, typically, a plurality of lens groups including a first lens group and a second lens group are arranged back and forth along the optical axis, and at least a part of the lens unit is in front of the body of the apparatus. These include a protruding usage state and a storage state in which the first lens frame is housed in the second position and the lens unit is substantially contained within the body of the apparatus.

1A and 1B are diagrams illustrating a schematic configuration of an example of an imaging apparatus (camera) including a zoom lens system according to an embodiment of the present invention, where FIG. 1A is a diagram illustrating an imaging state, and FIG. Sectional drawing which shows the zoom lens system in a park position cut | disconnected along an optical axis. Sectional drawing which shows the zoom lens system in a wide position cut | disconnected along an optical axis. Sectional drawing which shows the zoom lens system in a teleposition cut | disconnected along an optical axis. Sectional drawing which cut | disconnects and shows the storage start state (wide position) of a zoom lens system so that a movement mechanism can be seen. Sectional drawing which cut | disconnects and shows the 1st state in the middle of accommodation of a zoom lens system so that a moving mechanism can be seen. Sectional drawing which cut | disconnects and shows the 2nd state in the middle of accommodation of a zoom lens system so that a moving mechanism can be seen. Sectional drawing which cut | disconnects and shows the accommodation completion state (park position) of a zoom lens system in the state which can see a moving mechanism. It is a perspective view which shows a part of lens system, Comprising: The perspective view which shows the state in which the 1st lens frame (3 group lens frame) is arrange | positioned in the 1st position (use position). It is a perspective view which shows a part of lens system, Comprising: The perspective view which shows the state in which the 1st lens frame (3 group lens frame) is arrange | positioned in the 2nd position (a storing position, a retracted position). It is a perspective view which shows a moving mechanism, Comprising: The perspective view which shows the state in which the 1st lens frame (3 group lens frame) is arrange | positioned in the 1st position (use position). It is a perspective view which shows a moving mechanism, Comprising: The perspective view which shows the state in which the 1st lens frame (3rd group lens frame) is arrange | positioned in the 2nd position (storage position, retracted position). The disassembled perspective view which shows a moving mechanism. Sectional drawing cut | disconnected and shown along the XIV-XIV line | wire in FIG. Sectional drawing cut | disconnected and shown along the XV-XV line | wire in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B show a schematic configuration of an example of an imaging apparatus (camera) including a zoom lens system according to the present invention. FIG. 1A shows an imaging state (use state, for example, a telephoto position (teleposition)), and FIG. 1B shows a storage state (park position).

  As shown in FIG. 1A, an imaging apparatus (camera) 100 of this example includes a housing (body, housing) 101, an imaging module 3 including a zoom lens system 1 and an imaging unit 2, and the apparatus (camera). ) A control unit 102 for controlling 100 and a motor 103 for driving the zoom lens system 1.

  As the housing 101, for example, an overall thin and flat shape such as a box shape is employed. The zoom lens system (lens unit) 1 of the image pickup module 3 includes a lens holder 10 including a multistage cylinder (cam cylinder and lens barrel) that is extended, and a first group to a fourth group that are supported by the multistage cylinder of the lens holder 10. The group lens frames 11, 12, 13, and 14 (see FIG. 2) and the first to fourth lens groups 21, 22, and 23 supported by the first to fourth group lens frames 11, 12, 13, and 14, respectively. , 24. The extension of the lens holder 10 and the subsequent expansion / contraction amount are controlled by the motor 103.

  The imaging unit 2 is disposed rearward along the optical axis L of the zoom lens system 1. The imaging unit 2 is a unit that acquires an image formed by the zoom lens system 1, and a typical one is a semiconductor imaging device such as a CCD or a CMOS. An image formed on the imaging unit 2 by the zoom lens system 1 is stored as digital data in a memory (not shown) provided in the housing 101.

  The camera 100 of this example further includes a display device 104 that displays an image formed on the imaging unit 2 by the zoom lens system 1 on the rear surface of the housing 101. As the display device 104, for example, a liquid crystal display device can be used. Since the camera 100 can store the zoom lens system 1 in the housing 101, the size when carried is compact. On the other hand, when imaging, since the multistage lens holder 10 can be extended, there is an advantage that the zoom ratio (magnification, magnification range) is large (wide).

  As shown in FIG. 1B, when the lens holder 10 is folded by overlapping the multistage cylinders of the lens holder 10, the zoom lens system 1 is in a park state in which it is housed in the housing 101. On the other hand, as shown in FIG. 1A, when the multistage tube of the lens holder 10 is extended, the zoom lens system 1 is protruded in front of the housing 101 and is ready for imaging (use state). Further, since the position (distance) of the lens holder 10 along the optical axis L of the first to fourth lens groups 21 to 24 is variable, zooming in a wide angle (wide) range and a telephoto (telephoto) range is possible. .

  2 to 4 show several states of the imaging module 3 including the zoom lens system 1 in cross-sectional views cut along the optical axis L. FIG. Hereinafter, the front side (left side in the figure) along the optical axis L indicates the subject side, and the rear side (right side in the figure) indicates the imaging side (imaging unit 2 side).

  FIG. 2 shows the park position (park state) of the imaging module 3. At the park position, the first to fourth lens groups 21 to 24 are housed in the housing 101, and the first to fourth lens groups 21 to 24 including the lens holder 10 are retracted into the housing 101. In the park position, the third lens group 23 is disposed (retracted and retracted) at a position (retracted position and retracted position) deviated upward from the optical axis L in the drawing.

  FIG. 3 shows the wide position of the imaging module 3. The wide position is a position where the lens holder 10 stops immediately after being extended from the park position, and the zoom lens system 1 is set to the wide (wide angle end). In the wide position, the lens holder 10 protrudes from the housing 101, the first to fourth lens groups 21 to 24 are arranged in order from the front side along the optical axis L, and the third lens group 23 also has an optical axis of the lens group. The zoom lens system 1 is arranged in a use state in which the optical axis L of the zoom lens system 1 matches. In this zoom lens system 1, the first lens group 21 and the second lens group 22 approach each other at a wide position, and the second lens group 22 and the third lens group 23 are separated from each other. The interval is not limited to this example.

  FIG. 4 shows the teleposition of the imaging module 3. The teleposition is a state in which the zoom lens system 1 is set to the telephoto (telephoto end). Like the wide position, the lens holder 10 protrudes from the housing 101, and the first to fourth lens groups 21 to 24 are optical axes. The lens units 21 to 24 are arranged in front and back in order from the front side along L, and the optical axis of the lens groups 21 to 24 and the optical axis L of the zoom lens system 1 coincide with each other. In the zoom lens system 1, the first lens group 21 and the second lens group 22 are separated from the wide position in the tele position, and the second lens group 22 and the third lens group 23 are close to each other. The interval between 21 and 24 is not limited to this example.

  As shown in these drawings, the zoom lens system 1 of this example includes a cylindrical base (body, fixed cylinder) 4, and all elements can be stored in the base 4 in a park state. The zoom lens system 1 further includes a multi-cylinder type lens holder 10 configured to be extended from the base 4, and first to fourth group lens frames 11 to 14 supported by each cylinder of the lens holder 10. , And first to fourth lens groups 21 to 24 supported by the first to fourth group lens frames 11 to 14, respectively. The lens holder 10 includes a shutter module 19 that is attached to an inner cylinder 44 that supports the third lens group 23 and moves together with the third lens group 23. The imaging unit 3 is configured by disposing the imaging unit 2 behind the zoom lens system 1 along the optical axis L.

  The lens holder 10 has a multistage structure in which a large number of cylinders housed in the base 4 are overlapped and expanded and contracted, and first and second cam cylinders (cam rings) 31 and 32 that are rotationally driven by a motor 103. , And cylinders 41, 42, 43, 44 that move back and forth with them.

  A first group lens frame 11 that supports a first lens group 21 including one or a plurality of lenses is attached to the innermost first cylindrical body (first shell) 41. The first cylinder 41 includes a cover glass 41 b that covers the front of the zoom lens system 1. The first cylinder 41 includes a cam pin 41 a and moves back and forth along the optical axis L by a cam groove 32 b on the outer peripheral surface of the second cam cylinder 32.

  The second cylinder (second shell) 42 outside the first cylinder 41 has the second cam cylinder 32 disposed on the inside, and moves forward and backward together with the cam cylinder 32. Specifically, the cam cylinder 32 moves back and forth while rotating, and the cylinder 42 advances straight. The second cam cylinder 32 includes a cam pin 32 a and moves back and forth along the optical axis L by the cam groove 31 a of the first cam cylinder 31. The second cam cylinder 32 includes cam grooves 32c and 32d on the inner peripheral surface. The cam groove 32c moves the second group lens frame 12 supporting the second lens group 22 composed of one or more lenses back and forth along the optical axis L via the cam pin 12a. The cam groove 32d moves the inner cylinder 44 that further supports the third lens group frame 13 that supports the third lens group 23 composed of one or a plurality of lenses back and forth along the optical axis L via the cam pin 13a. move.

  The third cylinder 43 on the outer side of the second cylinder 42 includes the first cam cylinder 31 on the inner side, and is guided to the groove 4a formed on the inner peripheral surface of the base 4 via the pin 43a. It is driven back and forth along the optical axis L together with the cylinder 31.

  In the imaging module 3, the third group lens frame 13 corresponds to the first lens frame recited in the claims, and the first group lens frame 11, the second group lens frame 12, and / or the fourth group. The lens frame 14 corresponds to a second lens frame described in the claims.

  The inner cylinder 44 of the imaging module 3 includes a moving mechanism 50 that moves the third group lens frame 13 in a first direction perpendicular to the optical axis L. FIGS. 5 to 8 show how the third lens group frame 13 is moved in a first direction perpendicular to the optical axis L to shift from the imaging state (wide position) to the retracted state (park position). Yes. 9 and 10 show the inner cylinder 44 as viewed from the rear. FIG. 9 shows a state in which the third group lens frame 13 is disposed at the first position (use position, imaging position). FIG. 10 shows a state in which the third group lens frame 13 is disposed at the second position (storage position, retracted position).

  The moving mechanism 50 includes a pair of guides (first guide 51 and second guide 52) provided on the wall surface 45 perpendicular to the optical axis L of the inner cylinder 44. The first guide 51 and the second guide 52 extend in a first direction perpendicular to the optical axis L, and are arranged at an interval across the opening 46 of the wall surface 45. The first guide 51 is a rod-shaped guide, the second guide 52 is a guide protruding from the wall surface 45, and the first slider 61 and the second slider 62 at both ends of the third group lens frame 13 are These are moved up and down along the first guide 51 and the second guide 52, respectively.

  The third group lens frame 13 includes a ring-shaped portion 60 that supports the third lens group 23, and first and second sliders 61 and 62 that are provided across the ring-shaped portion 60. The first and second sliders 61 and 62 slide up and down in contact with the first guide 51 and the second guide 52, respectively, and the optical axis of the third lens group is the zoom lens system. The first optical axis L is set to the first position (use position, imaging position), and the third lens group is moved to the second position (retracted position, storage position) away from the optical axis L. .

  The moving mechanism 50 further includes a first stopper 53 that stops the third group lens frame 13 at the first position, and a second stopper 54 that stops the third group lens frame 13 at the second position. . In this example, the first stopper 53 and the second stopper 54 are provided on the inner cylinder 44.

  11, 12, and 13 show the vicinity of the first slider 61. The first slider 61 of the third group lens frame 13 is U-shaped, and includes a first passive portion 63 provided on the first position side and a second passive portion 63 provided on the second position side. A passive unit 64. The first stopper 53 stops the third group lens frame 13 at the first position by contacting the first passive portion 63. The second stopper 54 comes into contact with the second passive portion 64 to stop the third group lens frame 13 at the second position. The moving mechanism 50 further includes a third slider 65 that moves along the first guide 51 between the first passive portion 63 and the second passive portion 64 of the third group lens frame 13; And an elastic member 66 disposed between the third slider 65 and the second passive portion 64, and a drive mechanism 57 that drives the third slider 65.

  The drive mechanism 57 meshes with the arm 58 that moves the protrusion 65a of the third slider 65 up and down, the first gear 71 that is integrated with the arm 58 and pivots the arm 58 up and down, and the first gear 71. It includes a second gear 72 that drives the first gear 71 and a spring 73 that is attached to press the first gear 71 downward, that is, to the first position. The second gear 72 includes a passive lever 72a disposed so as to be pushed rearward, that is, from the imaging unit 2 side.

  As shown in FIG. 5, the base 4 to which the imaging unit 2 of the imaging module 3 is attached is provided with a drive lever 79 protruding forward, that is, in the direction of the first lens group 21. In the state of the wide position before the start of storage shown in FIG. 5, the drive lever 79 is not in contact with the drive mechanism 57. Therefore, the first gear 71 of the drive mechanism 57 forcibly turns the arm 58 toward the first position by the spring 73. For this reason, the protrusion 65a of the third slider 65 is pressed downward (in the direction of the first position) by the force of the spring 73 via the arm 58. The first slider 61 is pressed in the direction of the first position by the third slider 65, and stops at the first stopper 53. Therefore, the third lens group 23 supported by the third group lens frame 13 is held at a predetermined position determined by the first stopper 53. Since the arm 58 is pressed toward the first position by the force (elastic force) of the spring 73, the third lens group frame 13 is predetermined by the first stopper 53 even if some parts have tolerances. (Position along the optical axis L) is reasonably held.

  As shown in FIG. 6, when the lens holder 10 is retracted from the wide position, the inner cylinder 44 moves toward the base 4, and the drive lever 79 contacts the passive lever 72 a of the second gear 72. As shown in FIG. 7, when the lens holder 10 is further retracted, the distance between the inner cylinder 44 and the base 4 is shortened, the drive lever 79 moves the passive lever 72a of the second gear 72 upward, The second gear 72 is turned clockwise in FIG. Thereby, the second gear 72 turns the first gear 71 counterclockwise against the spring 73, and the first gear 71 turns the arm 58 upward (in the direction of the second position).

  As shown in FIG. 8, when the imaging module 3 is in the park position, the arm 58 is moved upward (second position) by the drive lever 79 via the second gear 72 and the first gear 71. For this reason, the protrusion 65a of the third slider 65 is moved upward (in the direction of the second position) via the arm 58. The first slider 61 is pressed in the direction of the second position by the third slider 65 and stops at the second stopper 54. Therefore, the third lens group 23 supported by the third group lens frame 13 is held at a predetermined position determined by the first stopper 53. Since the arm 58 is pressed toward the first position by the force (elastic force) of the spring 73, the third lens group frame 13 is predetermined by the first stopper 53 even if some parts have tolerances. (Position along the optical axis L) is reasonably held.

  FIG. 14 shows a state of the first slider 61 and the third slider 65 at the first position (use position, imaging position) by a cross section cut along the line XIV-XIV in FIG. FIG. 15 shows the state of the first slider 61 and the third slider 65 at the second position (storage position, retracted position) by a cross section cut along the line XV-XV in FIG. Yes.

  The first slider 61 of the third lens group frame 13 includes a cylindrical member 61a extending in the first direction, and the inside 61b of the cylindrical member 61a becomes a cavity, and the third slider 65 becomes a cavity 61b. Has been inserted. Therefore, the third slider 65 slides up and down (moves) along the first guide 51 in the cavity 61b, and one end (end on the first position side) and the other end of the cylindrical member 61a. The first slider 61 is moved as the first passive portion 63 and the second passive portion 64 (ends on the second position side), respectively.

  The third slider 65 has an abutting portion 69 that contacts the first passive portion 63 on the second guide 52 side with respect to the first guide 51 at an end (end surface) 65b on the first position side. (See FIGS. 13 to 15). That is, the third slider 65 has a contact portion 69 provided at a position (inner side) of the end surface 65b on the first position side closer to the optical axis L side than the central axis of the first guide 51. Is included. The contact portion 69 may be provided on the optical axis L side (inner side) with respect to the central axis of the first guide 51 of the first passive portion 63. Further, the abutting portion 69 may be provided so as to abut on both the third slider 65 and the first passive portion 63. Therefore, the third slider 65 is in contact with the first passive portion 63 of the first slider 61 through the abutting portion 69 inside the first guide 51 at the first position.

  On the other hand, a coil spring 66 that is an elastic member is disposed between the third slider 65 and the second passive portion 64. Furthermore, a dent 68 that houses a part of the coil spring 66 is provided at the end (end surface) 65 c on the second position side of the third slider 65. The coil spring 66 has a diameter that can move (slide) along with the third slider 65 along the first guide 51. Accordingly, the third slider 65 contacts the second passive portion 64 of the first slider 61 via the coil spring 66 in the second position. The elastic member 66 is not limited to a coil spring, and may be, for example, a cylindrical elastomer.

  In the imaging module 3 including the zoom lens system 1, the third group lens frame 13 is moved in the first direction (vertical direction in the drawing) perpendicular to the optical axis L by the moving mechanism 50, and the third lens group 23. Can be set to both the first position set on the optical axis L and the second position away from the optical axis L.

  At the first position, the third lens group 23 supported by the third group lens frame 13 is set to the optical axis L. At that time, the third slider 65 is driven to the first position side (the lower side in FIGS. 9 to 12, 14, and 15) by the arm 58 pressed to the first position side by the spring 73. , Retained. Accordingly, the first passive portion 63 of the first slider 61 of the third group lens frame 13 is in contact with the first stopper 53 while being biased by the spring 73. For this reason, the third lens group frame 13 is stably held at the first position.

  Further, the third slider 65 drives the first passive portion 63 of the first slider 61 on the optical axis L side with respect to the central axis of the first guide 51 via the contact portion 69. Therefore, the first slider 61 is driven in a state where a force is applied inside the first guide 51 and the second guide 52 forming a pair of rails, and is held at the first position. For this reason, the third group lens frame 13 is unlikely to generate a moment for turning the third group lens frame 13 in the opposite direction with respect to the optical axis L with the first guide 51 as the center. Therefore, the third lens group 23 supported by the third group lens frame 13 can be held in an optically accurate and stable state with respect to the optical axis L.

  The drive mechanism 57 for moving the third group lens frame 13 up and down includes a number of parts such as first and second gears 71 and 72 and an arm 58. Therefore, in consideration of interference with other lens groups and lens frames, space efficiency inside the lens holder 10 and the like, the first guide 51 is driven to a position close to the third lens group 23 on the optical axis L side. It is difficult to arrange the mechanism 57. If the first guide 51 is set at a position close to the circumference of the lens holder 10, there is a possibility that a stroke for moving the third group lens frame 13 to the retracted position (second position) cannot be secured. Accordingly, it is desirable that the drive mechanism 57 be disposed outside the first guide 51 (on the side opposite to the optical axis L). However, when the first slider 61 is driven outside the first guide 51, The moment in the direction separating the third lens group frame 13 from the optical axis L around the one guide 51 is likely to occur. For this reason, the third group lens frame 13 is easily tilted during movement or at the first position.

  In the moving mechanism 50 of the present example, a third slider 65 that moves separately from the first slider 61 is disposed inside the first slider 61, and the third slider 65 is placed outside the first guide 51. And the third slider 65 is applied to the inside of the first slider 61 (on the optical axis L side of the first guide 51), and a force is applied to the inside of the first slider 61 via the third slider 65. It can be driven by adding. For this reason, a moment around the first guide 51 is less likely to be generated in the third lens group frame 13, and it is possible to suppress tilting during movement or at the first position. Therefore, the third lens group 23 can be set and held at a predetermined position along the optical axis L.

  On the other hand, in the second position, the third slider 65 is driven and held by the first and second gears 71 and 72 and the arm 58, but the third slider 65 is connected via the coil spring 66. The second passive portion 64 of the first slider 61 is pressed. Accordingly, the first slider 61 is elastically pressed against the second stopper 54 even at the second position, and the third group lens frame 13 is in the second position (retracted position) determined by the second stopper 54. Can be stored accurately. Further, even if the stop position on the second position side of the third slider 65 slightly fluctuates, the third group lens frame 13 absorbs the fluctuation by the coil spring 66, so the inner cylinder 44 and the third group The lens frame 13 is housed in a predetermined position determined by the second stopper 54 without causing an excessive load.

  Thus, in the lens holder 10 provided with the moving mechanism 50, the third group lens frame 13 can be moved more accurately between the first position and the second position. For this reason, a clearer image can be acquired in the use state in which the third lens group 23 is set at the first position. In the retracted state in which the third lens group 23 is retracted to the second position, the clearance between the third lens group 23 and the third group lens frame 13 and other parts can be minimized, and the lens holder The space inside 10 can be used more effectively, the larger third lens group 23 can be stored, and the storage state can be made more compact.

  In the moving mechanism 50, the third lens group frame 13 is elastically pressed against the stoppers 53 and 54 at the first position in the use state and the second position in the retracted state (retracted state). The position is determined. For this reason, even if there are some tolerances in the components constituting the moving mechanism 50, the tolerance can be absorbed by the elastic force of the spring 73 and the coil spring 66. For this reason, it is possible to prevent a situation in which an excessive force is applied to the components constituting the lens holder 10 and the optical balance is out of order to deteriorate the optical performance or the mechanical life.

  In the above description, the third lens group frame 13 having the four-group configuration is used as the first lens frame to be moved, but any one of the other lens frames 11, 12, and 14 having the four-group configuration is the first lens frame to be moved. It is possible to use a lens frame. In the above description, the zoom lens system 1 having a four-group configuration including the first to fourth lens groups 21 to 24 is described as an example. However, a lens system having a configuration of three or less groups or a configuration of five or more groups is described. The present invention can also be applied to this lens system, and as the first lens frame to be moved, a lens frame that supports any one or a plurality of lens groups can be selected.

  In the above description, the camera 100 equipped with the zoom lens system 1 is described as an example. However, the zoom lens system 1 is applied to an optical product in which it is desirable that the lens is retracted or the length is shortened when stored. it can. For example, by adopting the above configuration in a zoom lens system of a handy type projector using an LED light source, a projector that is more compact when carried can be provided.

DESCRIPTION OF SYMBOLS 1 Zoom lens system, 10 Lens holder 13 1st lens frame (3rd group lens frame), 50 Moving mechanism 51 1st guide, 52 2nd guide 53 1st stopper, 54 2nd stopper 57 Drive mechanism 61 first slider 62 second slider 63 first passive portion 64 second passive portion 65 third slider 66 elastic member (coil spring)
100 cameras

Claims (7)

A moving mechanism for moving a first lens frame supporting at least one lens in a first direction inclined with respect to the optical axis;
A first guide and a second guide extending in the first direction;
The first lens frame includes a first slider and a second slider that slide in contact with the first guide and the second guide, respectively, and the at least one lens is set to the optical axis. a first position, said at least one lens when not in use is remote from the optical axis, to move to the second position Ru position der to retract the first lens frame,
further,
A first stopper for stopping the first lens frame at the first position;
A second stopper for stopping the first lens frame at the second position;
The first guide between the first passive portion on the first position side of the first slider and the second passive portion on the second position side of the first slider. A third slider that moves along
An elastic member disposed between the third slider and the second passive portion;
A moving mechanism having a driving mechanism for driving the third slider. In claim 1,
The moving mechanism, wherein the third slider and / or the first passive portion includes an abutting portion that contacts the first guide on the side of the second guide. In Claim 1 or 2, the elastic member is a coil spring,
The third slider is a moving mechanism including a recess into which a part of the coil spring enters on the second guide side. A moving mechanism according to any one of claims 1 to 3,
The first lens frame moved by the moving mechanism;
A second lens frame supporting at least one lens, the second lens frame moving along the optical axis and changing a relative distance between the second lens frame and the first lens frame; A lens holder. In claim 4,
The first holder is a lens holder that uses the at least one lens supported by the first lens frame and the at least one lens supported by the second lens frame. The lens holder according to claim 4 or 5,
The at least one lens supported by the first lens frame;
A lens system including the at least one lens supported by the second lens frame; A lens system according to claim 6;
A camera having an image pickup device for picking up an image formed by the lens system;

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