JP2006145743A - Lens moving mechanism, imaging apparatus, and lens holding frame - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the quality of a photographic image and to miniaturize a lens moving mechanism, an imaging apparatus, and a lens holding frame. <P>SOLUTION: The lens moving mechanism includes movable lenses for zooming or for focusing 17 and 19 arranged inside a lens barrel 10, the lens holding frame 20 supported to freely move in an optical axis direction for holding the movable lens, guide shafts 26 and 26 for guiding the lens holding frame in the optical axis direction when the lens holding frame moves, and driving means 29 and 30 for moving the lens holding frame in the optical axis direction. The lens holding frame includes a holding part 21 for holding the movable lens and a movable part 22 arranged at the outer circumference part of the holding part and made to act on the holding part, and the movable part is made to act on the holding part with the movement of the lens holding frame in the optical axis direction so that the external shape of the lens holding frame seen from the optical axis direction may be changed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technical field regarding a lens moving mechanism, an imaging device, and a lens holding frame. More specifically, the present invention relates to a technical field in which a movable portion is provided in a lens holding frame that holds a movable lens to improve the quality of a captured image and to reduce the size of a lens moving mechanism, an imaging device, and a lens holding frame.

  Some imaging apparatuses such as video cameras and still cameras have a movable lens for zooming or focusing in a lens barrel, and the movable lens is held by a lens holding frame (for example, Patent Document 1). reference).

  An example of a camera block provided in such a conventional imaging device is shown below (see FIG. 6).

  The camera block a of the imaging apparatus has a lens barrel b formed in a substantially cylindrical shape, and various lenses or lens groups (hereinafter referred to simply as “lens”) constituting the imaging optical system inside the lens barrel b. ”) Is arranged. The lens barrel b has a first lens arrangement portion c located on the subject side (front side), an iris arrangement portion d located on the rear side, and a second lens arrangement portion e located on the rear side. .

  Inside the lens barrel b, for example, a lens having a four-group configuration is arranged, and an objective lens f, a variable power lens g, a lens h, and a focus lens i are sequentially arranged from the subject side. The zoom lens g functions as a movable lens for zooming, and the focus lens i functions as a movable lens for focusing.

  The objective lens f and the lens h are fixed to the lens barrel b. The zoom lens g is held by a lens holding frame j, and the focus lens i is held by a lens holding frame (not shown).

  The lens holding frame j that holds the variable magnification lens g is movable in the optical axis direction in the first lens arrangement portion c, and the lens holding frame that holds the focus lens i is in the optical axis direction in the second lens arrangement portion e. It is possible to move to. When the lens holding frame j holding the variable magnification lens g is moved forward, the wide angle is obtained, and when the lens holding frame j is moved rearward, the telephoto is obtained.

  The lens holding frame j for holding the variable magnification lens g and the lens holding frame for holding the focus lens i are moved in the optical axis direction by a lens driving mechanism (not shown) having a stepping motor and a lead screw, for example.

  The lens holding frame j is integrally formed with a holding portion k that holds the variable magnification lens g and a light shielding portion l that protrudes outward from the outer peripheral portion of the holding portion k.

  An imaging element m such as a CCD (Charge Coupled Device) is arranged as an imaging means at the rear end of the lens barrel b.

  An iris mechanism n having a pair of iris blades is arranged in the iris arrangement portion c of the lens barrel b, and the iris mechanism n is operated by a drive motor o.

  In the camera block a configured as described above, at the time of imaging, light P is incident on the inside of the lens barrel b from the subject side via the objective lens f. When the lens holding frame j is at the telephoto position, the entire condensed light P is incident on the zoom lens g, but when the lens holding frame j is on the wide angle position side from the telephoto position, the light P Is incident on the zoom lens g.

  At this time, the light P that is not incident on the variable magnification lens g is blocked by the light-shielding portion l of the lens holding frame j, thereby preventing unnecessary light from entering the lens h side. By preventing such unnecessary light from entering, it is possible to improve the quality of the captured image.

JP 2000-147350 A

  By the way, since the light P incident on the inside of the lens barrel b is collected, the amount of the light P that needs to be blocked by the light blocking portion l decreases as the lens holding frame j moves from the wide-angle position to the telephoto position. In particular, since the entire light P is incident on the variable magnification lens g at the telephoto position, the light shielding portion l is not necessary.

  However, in the conventional imaging device a, since the light-shielding portion l projecting outward from the holding portion k is integrally provided on the lens holding frame j, the first lens arrangement of the lens barrel b is provided. The part c has a shape extending in parallel with the optical axis corresponding to the movement locus of the light shielding part l, and there is a problem that the outer shape of the lens barrel b is correspondingly large and the imaging device becomes large.

  SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to overcome the above-described problems, to improve the quality of a captured image, and to reduce the size of a lens moving mechanism, an imaging device, and a lens holding frame.

  In order to solve the above-described problem, the lens moving mechanism of the present invention holds a movable lens for zooming or focusing disposed inside the lens barrel, the movable lens inside the lens barrel, and the movable lens. A lens holding frame supported movably in the optical axis direction of the lens, a guide shaft for guiding the lens holding frame in the optical axis direction of the movable lens when the lens holding frame is moved, and an optical axis of the movable lens. And a lens holding frame having a holding portion that holds the movable lens and a movable portion that is provided on the outer peripheral portion of the holding portion and is operated with respect to the holding portion. In accordance with the movement in the optical axis direction, the movable portion is operated with respect to the holding portion so that the outer shape of the lens holding frame as viewed from the optical axis direction is changed.

  In order to solve the above-described problems, the imaging apparatus of the present invention has a lens barrel in which a movable lens for zooming or focusing is disposed, and holds the movable lens inside the lens barrel and moves the movable lens. A lens holding frame supported movably in the optical axis direction of the lens, a guide shaft for guiding the lens holding frame in the optical axis direction of the movable lens when the lens holding frame is moved, and an optical axis of the movable lens. And a lens holding frame having a holding portion that holds the movable lens and a movable portion that is provided on the outer peripheral portion of the holding portion and is operated with respect to the holding portion. In accordance with the movement in the optical axis direction, the movable portion is operated with respect to the holding portion so that the outer shape of the lens holding frame as viewed from the optical axis direction is changed.

  In order to solve the above-described problem, the lens holding frame of the present invention includes a holding portion that holds the movable lens, and a movable portion that is provided on the outer peripheral portion of the holding portion and is operated with respect to the holding portion. In accordance with the movement in the direction, the movable portion is operated with respect to the holding portion so that the outer shape viewed from the optical axis direction changes.

  Therefore, in the lens moving mechanism, the imaging device, and the lens holding frame according to the present invention, the lens mirror is adapted to the size of the lens holding frame whose outer shape as viewed from the optical axis direction changes with the movement in the optical axis direction. The outer shape of the cylinder can be designed.

  The lens moving mechanism of the present invention includes a movable lens for zooming or focusing disposed inside a lens barrel, and holds the movable lens inside the lens barrel and is movable in the optical axis direction of the movable lens. A supported lens holding frame; a guide shaft that guides the lens holding frame in the optical axis direction of the movable lens when the lens holding frame is moved; and a drive unit that moves the lens holding frame in the optical axis direction of the movable lens. The lens holding frame has a holding portion that holds the movable lens and a movable portion that is provided on the outer peripheral portion of the holding portion and is operated with respect to the holding portion, and the lens holding frame is moved in the optical axis direction. The movable part is operated with respect to the holding part, and the outer shape of the lens holding frame as seen from the optical axis direction is changed.

  Accordingly, the size of the lens holding frame can be changed according to the position of the lens holding frame in the optical axis direction, and the quality of the photographed image can be improved by preventing unnecessary light from entering the image sensor side, and the lens can be moved. The mechanism can be miniaturized.

  In the invention described in claim 2, the lens barrel is formed with a displacement portion that is displaced inward as the distance from the subject in the optical axis direction, and the movable portion is urged against the inner surface of the displacement portion. When the lens holding frame is moved in the optical axis direction, the movable portion slides on the inner surface of the displacement portion and follows the shape of the inner surface by the urging means, so that the outer shape viewed from the optical axis direction of the movable portion. Therefore, the movable part can be reliably operated with a simple configuration.

  In the invention described in claim 3, a displacement portion that is displaced inward as the distance from the subject in the optical axis direction is formed in the lens barrel, and the movable portion is elastically deformed to be elastically deformed as the movable portion. When the lens holding frame is moved in the optical axis direction by using an elastic member that is pressed against the inner surface, the movable portion is slidably contacted with the inner surface of the displacement portion by the biasing means and elastically deforms to follow the shape of the inner surface. Since the outer shape viewed from the direction of the optical axis changes, the lens moving mechanism can be reduced in size and the quality of the captured image can be improved while reducing the number of components.

  In the invention described in claim 4, the lens holding frame is pressed against the guide shaft during the movement in the optical axis direction by the reaction force generated in the movable portion pressed against the inner surface of the lens barrel by the biasing means. As a result, the movement of the lens holding frame in the plane perpendicular to the optical axis direction with respect to the guide axis is prevented, the occurrence of so-called image fluctuation reduction in which the image on the imaging plane slightly fluctuates, and the quality of the captured image is suppressed. Can be improved.

  In the invention described in claim 5, since the lens holding frame is pressed against the guide shaft during the movement in the optical axis direction by the reaction force generated in the elastic member pressed against the inner surface of the lens barrel. The movement of the lens holding frame in the plane perpendicular to the optical axis direction with respect to the guide axis is prevented, and the occurrence of so-called image fluctuation reduction in which the image on the imaging plane is slightly shaken is suppressed, thereby improving the quality of the photographed image. Can do.

  In the invention described in claims 6 and 7, the pressing force of the lens holding frame against the guide shaft is changed in accordance with the position of the movable lens. The applied voltage can be kept low, and the power consumption can be reduced while improving the quality of the captured image.

  In the invention described in claims 8 and 9, when the movable lens is for zooming, the pressing force of the lens holding frame against the guide shaft increases as the distance from the subject increases. The phenomenon can be efficiently prevented, and the quality of the captured image can be improved efficiently.

  In the tenth and eleventh aspects of the present invention, when the movable lens is for focusing, the pressing force of the lens holding frame against the guide shaft is increased as it approaches the subject. The phenomenon can be efficiently prevented, and the quality of the captured image can be improved efficiently.

  In the invention described in claims 12 to 15, since the applied voltage to the driving means is changed in accordance with the position of the lens holding frame with respect to the guide shaft, voltage control during movement of the lens holding frame is performed. Can be made more efficient.

  The imaging apparatus according to the present invention includes a lens barrel in which a zoom or focus movable lens is disposed, and holds the movable lens inside the lens barrel and is movable in the optical axis direction of the movable lens. A supported lens holding frame; a guide shaft that guides the lens holding frame in the optical axis direction of the movable lens when the lens holding frame is moved; and a drive unit that moves the lens holding frame in the optical axis direction of the movable lens. The lens holding frame has a holding portion that holds the movable lens and a movable portion that is provided on the outer peripheral portion of the holding portion and is operated with respect to the holding portion, and the lens holding frame is moved in the optical axis direction. The movable part is operated with respect to the holding part, and the outer shape of the lens holding frame as seen from the optical axis direction is changed.

  Therefore, the size of the lens holding frame can be changed in accordance with the position of the lens holding frame in the optical axis direction, and the quality of the photographed image can be improved by preventing the unnecessary light from entering the imaging element side, and the imaging apparatus. Can be miniaturized.

  The lens holding frame of the present invention is a lens holding frame that is disposed inside a lens barrel and holds a movable lens for zooming or focusing, and is supported so as to be movable in the optical axis direction of the movable lens. A holding unit for holding, and a movable unit that is provided on an outer peripheral portion of the holding unit and is operated with respect to the holding unit, and the movable unit is operated with respect to the holding unit along with the movement in the optical axis direction. The outer shape seen from the axial direction is changed.

  Accordingly, the size of the lens holding frame can be changed in accordance with the position of the lens holding frame in the optical axis direction, and the quality of the photographed image can be improved by preventing the unnecessary light from entering the image sensor side and the lens holding. The size of the frame can be reduced.

  The best mode for carrying out the lens moving mechanism, the imaging device, and the lens holding frame of the present invention will be described below with reference to the accompanying drawings. In the best mode described below, the imaging device of the present invention is applied to a still camera, the lens moving mechanism of the present invention is applied to the lens moving mechanism used in the still camera, and the lens holding frame of the present invention is used for the still camera. Applied to the lens holding frame. Note that the scope of application of the present invention is not limited to a still camera, a lens moving mechanism used in a still camera, or a lens holding frame used in a still camera. The present invention can be applied to various imaging devices having a function of taking an image or various lens moving mechanisms and lens holding frames used in these imaging devices.

  As shown in FIG. 1, the imaging apparatus 1 (digital still camera) includes a camera block 2 having an imaging function, a camera signal processing unit 3 that performs signal processing such as analog-digital conversion of a captured image signal, and an image. An image processing unit 4 that performs signal recording / reproduction processing, a display unit 5 that displays captured images, a recording / reproduction unit 6 that performs recording / reproduction with respect to the recording medium 100, and a center that controls the entire imaging apparatus 1. An arithmetic processing unit 7, an input operation unit 8 for performing an operation input by a user, and a lens drive control unit 9 for controlling driving of various lenses of the camera block 2 are provided.

  The camera block 2 includes a lens barrel 10, an imaging optical system such as each lens disposed in the lens barrel 10, an imaging element 11 such as a CCD (Charge Coupled Device), and the like.

  The camera signal processing unit 3 performs signal processing such as conversion of an output signal (analog signal) from the image sensor 11 to a digital signal, noise removal, image quality correction, and conversion to a luminance signal or a color difference signal.

  The image processing unit 4 performs compression encoding / decompression processing of an image signal based on a predetermined image data format, conversion processing of data specifications such as resolution, and the like.

  The recording medium 100 is, for example, a detachable semiconductor memory.

  The display unit 5 is, for example, a liquid crystal display.

  The recording / reproducing unit 6 writes the image data encoded by the image processing unit 4 to the recording medium 100 and reads the image data recorded on the recording medium 100.

  The central processing unit 7 is a control processing unit that controls each circuit block provided in the imaging device 1, and controls each circuit block based on an instruction input signal from the input operation unit 8.

  The input operation unit 8 includes, for example, a shutter release button for performing a shutter operation, a selection switch for selecting an operation mode, and the like, and sends an instruction input signal corresponding to an operation by a user to the central processing unit 7. Output.

  Based on a control signal from the central processing unit 7, the lens drive control unit 9 is arranged in the lens barrel 10, for example, a zoom lens described later for zooming or a focus described later for focusing. A motor (not shown) that drives the lens is controlled.

  Below, operation | movement of the imaging device 1 is demonstrated easily.

  In the shooting standby state, under the control of the central processing unit 7, the image signal shot by the camera block 2 is output to the display unit 5 via the camera signal processing unit 3 and displayed as a camera through image. The

  When an instruction input signal for zooming is input from the input operation unit 8, the central processing unit 7 outputs a control signal to the lens drive control unit 9, and the lens mirror is controlled based on the control of the lens drive control unit 9. A later-described variable power lens disposed on the cylinder 10 is moved.

  In focusing, for example, when the shutter release button is half-pressed or when the shutter release button is fully pressed for recording, the lens drive control unit 9 operates the lens barrel based on the control signal from the central processing unit 7. This is performed by moving a focus lens, which will be described later, in 10.

  When a shutter (not shown) of the camera block 2 is operated by an instruction input signal from the input operation unit 8, the image signal is output from the camera signal processing unit 3 to the image processing unit 4, subjected to compression encoding processing, and a predetermined data format Converted to digital data. The converted data is output to the recording / reproducing unit 6 and written to the recording medium 100.

  When reproducing the image data recorded on the recording medium 100, predetermined image data is read from the recording medium 100 by the recording / reproducing unit 6 in response to an operation by the input operation unit 8, and the image processing unit 4 performs decompression decoding. After the conversion processing, the reproduced image signal is output to the display unit 5. As a result, a reproduced image is displayed.

  Next, a configuration example of the camera block 2 will be described.

  Various lenses or lens groups (hereinafter simply referred to as “lenses”) constituting the imaging optical system are arranged inside the lens barrel 10 of the camera block 2 (see FIG. 2).

  The lens barrel 10 has a first lens placement portion 12 located on the subject side (front side), an iris placement portion 13 located on the rear side, and a second lens placement portion 14 located on the rear side. . A part of the first lens arrangement portion 12, for example, a portion on the upper end side, includes a displacement portion 12a and a horizontal portion 12b continuous to the rear end. The displacement part 12a is inclined so as to be displaced inward as it goes backward along the light ray angle of the outer periphery of the light P incident into the lens barrel 10. The horizontal portion 12b is formed to extend in the direction of the optical axis OL of the light P.

  A concave portion 15 is formed in the lens barrel 10 by the displacement portion 12a and the horizontal portion 12b.

  Inside the lens barrel 10, for example, a four-group lens is arranged, and an objective lens 16, a variable power lens 17, a lens 18, and a focus lens 19 are sequentially arranged from the subject side. The zoom lens 17 functions as a movable lens for zooming, and the focus lens 19 functions as a movable lens for focusing.

  The objective lens 16 and the lens 18 are fixed to the lens barrel 10. The zoom lens 17 is held by a lens holding frame 20, and the focus lens 19 is held by a lens holding frame (not shown).

  The lens holding frame 20 that holds the variable magnification lens 17 is movable in the optical axis direction in the first lens arrangement portion 12, and the lens holding frame that holds the focus lens 19 is in the optical axis direction in the second lens arrangement portion 14. It is possible to move to. When the lens holding frame 20 holding the variable magnification lens 17 is moved forward, the wide angle is obtained, and when the lens holding frame 20 is moved rearward, the telephoto is obtained.

  The lens holding frame 20 includes a holding portion 21 that holds the zoom lens 17, a movable portion 22 that is operated with respect to the holding portion 21, and a sleeve portion 23 that is provided integrally with the holding portion 21. An engaging recess 21a is formed on the outer periphery of the holding portion 21 (see FIG. 3).

  The movable portion 22 is rotatably supported by the holding portion 21 by a hinge shaft 24 and rotates between a bent position where the movable portion 22 is bent forward with respect to the holding portion 21 and an initial position where the movable portion 22 is not bent with respect to the holding portion 21. It is possible.

  For example, a torsion coil spring 25 is supported on the hinge shaft 24 as urging means. The movable portion 22 is biased by a torsion coil spring 25 in one direction (R1 direction shown in FIG. 2) in the direction around the axis of the hinge shaft 24, and the distal end portion of the movable portion 22 is always the first lens placement portion. 12 is in elastic contact with the inner surface 12c.

  The engaging recess 21a and the sleeve portion 23 of the holding portion 21 are slidably engaged with guide shafts 26 and 26 arranged in parallel in the lens barrel 10, respectively.

  A nut member 27 is attached to the lens holding frame 20.

  A bracket 28 is fixed inside the lens barrel 10. The bracket 28 is composed of a fixed part 28a that is long in the front and rear directions and support surface parts 28b and 28c that protrude upward from both front and rear end parts of the fixed part 28a. The fixed part 28a is fixed to the lens barrel 10. .

  A lead screw 29 is rotatably supported between the support surface portions 28b and 28c, and the lead screw 29 is rotated about the axis by a stepping motor 30 disposed behind the support surface portion 28c. A nut member 27 attached to the lens holding frame 20 is screwed to the lead screw 29. The lead screw 29 and the stepping motor 30 function as driving means for moving the lens holding frame 20 in the optical axis direction. When the lead screw 29 is rotated along with the rotation of the stepping motor 30, the nut member 27 is moved to the stepping motor 30. The lens holding frame 20 is guided by the guide shafts 26 and 26 and moved back and forth, and the zoom lens 17 is moved in the optical axis direction.

  An iris mechanism 31 having a pair of iris blades (not shown) is disposed in the iris placement portion 13 of the lens barrel 10, and the iris mechanism 31 is operated by a drive motor 32.

  The focus lens 19 is moved in the optical axis direction in the same manner as the zoom lens 17, but the mechanism for moving the focus lens 19 is the same mechanism as the mechanism for moving the zoom lens 17, and thus the description thereof is omitted. .

  In the imaging apparatus 1 configured as described above, during imaging, the focus lens 19 is moved in the optical axis direction by focusing control, and when zoom control is performed, the stepping motor 30 is rotated so that the variable magnification lens 17 is moved to the optical axis. Moved in the direction. At this time, the light P is incident on the inside of the lens barrel 10 from the subject side via the objective lens 16, but the inner surface 12 c of the first lens placement portion 12 while the movable portion 22 rotates with respect to the holding portion 21. The lens holding frame 20 is moved in the front-rear direction while being pressed against the guide shafts 26, 26.

  When the zoom lens 17 is moved in the optical axis direction, the movable portion 22 is slid with respect to the inner surface 12c of the first lens placement portion 12 as described above, but the lens holding frame 20 moves the displacement portion 12a. The urging force by the torsion coil spring 25 increases as going backward. Accordingly, the pressing force of the lens holding frame 20 against the guide shafts 26 and 26 increases as the displacement portion 12a is moved backward.

  At this time, the applied voltage to the stepping motor 30 functioning as a driving unit is changed according to the position of the lens holding frame 20 in the optical axis direction in order to ensure a smooth operation of the lens holding frame 20. That is, when the movable portion 22 is in sliding contact with the displacement portion 12a, the applied voltage is increased as the lens holding frame 20 approaches the lens 18, and when the movable portion 22 is in sliding contact with the horizontal portion 12b. The applied voltage has the same height as the maximum applied voltage when the movable part 22 is in sliding contact with the displacement part 12a.

  When the lens holding frame 20 is at the telephoto position, the entire condensed light P is incident on the zoom lens 17, but when the lens holding frame 20 is on the wide-angle position side from the telephoto position, the light P Only a part of is incident on the zoom lens 17. Accordingly, the light that is not incident on the lens holding frame 20 becomes unnecessary light that is incident on the outside of the variable magnification lens 17, but this unnecessary light is blocked by the outer peripheral portion of the holding portion 21 of the lens holding frame 20 and the movable portion 22. Incident to the lens 18 side is prevented.

  As described above, in the imaging device 1, the lens holding frame 20 is provided with the movable portion 22 that is operated with respect to the holding portion 21, and the movable portion 22 that blocks unnecessary light with movement in the optical axis direction is provided. Since the outer shape of the lens holding frame 20 is operated with respect to the holding unit 21 and viewed from the optical axis direction, the size of the lens holding frame 20 is changed according to the position of the lens holding frame 20 in the optical axis direction. Thus, the quality of the captured image can be improved by preventing unnecessary light from entering the lens 18 and the image pickup apparatus 1 can be downsized.

  In particular, components such as a strobe, a microphone, and an autofocus auxiliary light emitting device are often arranged at positions around the first lens placement portion 12 of the lens barrel 10 by design. Since the recess 15 is formed, each of these parts can be arranged in the recess 15 and the degree of freedom of arrangement of each part is increased.

  Further, the outer shape of the movable portion 22 viewed from the optical axis direction is changed by pressing the movable portion 22 against the displacement portion 12a by the torsion coil spring 25 functioning as an urging means and following the shape of the displacement portion 12a. Therefore, the movable portion 22 can be reliably operated with a simple configuration.

  Further, due to the reaction force generated in the movable portion 22 pressed against the inner surface 12c of the lens barrel 10 by the torsion coil spring 25, the lens holding frame 20 moves the guide shafts 26, 26 when the lens holding frame 20 moves in the optical axis direction. Therefore, the movement of the lens holding frame 20 in the plane perpendicular to the optical axis direction with respect to the guide axes 26 and 26 is prevented, and the occurrence of so-called image fluctuation reduction in which the image on the imaging plane is slightly shaken is suppressed. The quality of the captured image can be improved.

  Furthermore, in the imaging apparatus 1, since the pressing force of the lens holding frame 20 against the guide shafts 26 and 26 varies depending on the position of the movable lens 22, a stepping motor that functions as a driving unit when the pressing force is small. The applied voltage to 30 can be kept low, and the power consumption can be reduced while improving the quality of the captured image.

  In addition, since the urging force of the torsion coil spring 25 on the lens holding frame 20 is changed by the movable portion 22 following the shape of the inner surface of the displacement portion 12b of the lens barrel 10, the lens holding frame can be surely secured with a simple configuration. The pressing force against the 20 guide shafts 26, 26 can be changed.

  In general, it is known that the amount of occurrence of the image shaking phenomenon increases as the position of the variable magnification lens 17 approaches the telephoto side. Accordingly, by adopting a configuration in which the urging force of the torsion coil spring 25 increases as the zoom lens 17 approaches the telephoto side as in the imaging device 1, the image shaking phenomenon can be efficiently prevented. Thus, the quality of the captured image can be improved efficiently.

  The above-described configuration in which the lens holding frame is urged and pressed against the guide shaft can be applied not only to the lens holding frame 20 that holds the variable magnification lens 17 but also to the lens holding frame that holds the focus lens 19. is there. In the case of this focus, it is generally known that the amount of occurrence of the above-described image shaking phenomenon increases as the position of the focus lens 19 approaches the subject. Therefore, when the configuration for applying the urging force to the lens holding frame that holds the focus lens 19 is applied, the configuration is such that the urging force increases as the distance from the subject increases. Therefore, the quality of the captured image can be improved efficiently.

  In the imaging apparatus 1, the voltage applied to the stepping motor 30 is changed according to the position of the lens holding frame 20 with respect to the guide shafts 26, 26. Can be achieved.

  Power consumption can be reduced by increasing the applied voltage in accordance with the pressing force of the lens holding frame 20 against the guide shafts 26 and 26.

  Below, the modification of a movable part is demonstrated (refer FIG.4 and FIG.5).

  The movable portion 22A according to the first modification is connected to the holding portion 21 by a compression coil spring 33 that functions as an urging means, and is movable in the vertical direction with respect to the holding portion 21 (see FIG. 4). . The movable portion 22A is always elastically contacted with the inner surface 12c of the lens barrel 10 by the urging force of the compression coil spring 33, and is slid with the inner surface 12c when the lens holding frame 20 moves in the optical axis direction.

  The movable portion 22B according to the second modification is, for example, a plate-like elastic member, and one end portion is attached to the holding portion 21 (see FIG. 5). The movable portion 22B is always elastically contacted with the inner surface 12c of the lens barrel 10 due to its elasticity, and slides with the inner surface 12c when the lens holding frame 20 moves in the optical axis direction.

  As described above, by using the elastic member as the movable portion 22B, it is possible to reduce the number of components and to reduce the size of the imaging device 1 and improve the quality of the captured image.

  Further, since the urging force on the lens holding frame 20 changes as the movable portion 22B, which is an elastic member, is elastically deformed to follow the shape of the displacement portion 12b, the number of parts is reduced, and the quality of the captured image is improved. The power consumption can be reduced.

  It should be noted that the up and down directions shown above are for convenience of explanation, and are not limited to these directions.

  The specific shapes and structures of the respective parts shown in the above-described best mode are merely examples of the implementation of the present invention, and the technical scope of the present invention is limited by these. It should not be interpreted in a general way.

FIG. 2 to FIG. 5 show the best mode of the present invention, and this diagram is a conceptual diagram showing the basic configuration of the imaging apparatus. It is an expanded sectional view of a camera block. It is an expansion perspective view of the principal part. It is an expanded sectional view of a camera block provided with a movable part concerning the 1st modification. It is an expanded sectional view of a camera block provided with the movable part concerning the 2nd modification. It is an expanded sectional view of the camera block in the conventional imaging device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Imaging device, 10 ... Lens barrel, 12a ... Displacement part, 12c ... Inner surface, 17 ... Variable magnification lens (movable lens), 19 ... Focus lens (movable lens), 20 ... Lens holding frame, 21 ... Holding part, DESCRIPTION OF SYMBOLS 22 ... Movable part, 25 ... Torsion coil spring (biasing means), 26 ... Guide shaft, 29 ... Lead screw (drive means), 30 ... Stepping motor (drive means), 22A ... Movable part, 33 ... Compression coil spring, 22B ... Movable part

Claims (17)

A movable lens for zooming or focusing disposed inside the lens barrel;
A lens holding frame that holds the movable lens inside the lens barrel and is supported movably in the optical axis direction of the movable lens;
A guide shaft for guiding the lens holding frame in the optical axis direction of the movable lens when the lens holding frame is moved;
Driving means for moving the lens holding frame in the optical axis direction of the movable lens,
The lens holding frame has a holding portion that holds the movable lens, and a movable portion that is provided on the outer peripheral portion of the holding portion and is operated with respect to the holding portion.
A lens moving mechanism characterized in that, as the lens holding frame moves in the optical axis direction, the movable part is operated with respect to the holding part so that the outer shape of the lens holding frame as viewed from the optical axis direction changes. Forming a displacement portion that is displaced inward as the distance from the subject in the optical axis direction in the lens barrel,
An urging means for pressing the movable part against the inner surface of the displacement part is provided,
When the lens holding frame moves in the optical axis direction, the urging means causes the movable portion to slidably contact the inner surface of the displacement portion so that the outer shape of the movable portion viewed from the optical axis direction changes. The lens moving mechanism according to claim 1, wherein: Forming a displacement portion that is displaced inward as the distance from the subject in the optical axis direction in the lens barrel,
As the movable part, an elastic member that is elastically deformed and pressed against the inner surface of the displacement part is used.
When the lens holding frame moves in the optical axis direction, the urging means causes the movable portion to slide in contact with the inner surface of the displacement portion and elastically deform to follow the shape of the inner surface, so that the outer shape viewed from the optical axis direction of the movable portion. The lens moving mechanism according to claim 1, wherein the lens is changed. 3. The lens holding frame is configured to be pressed against the guide shaft during movement in the optical axis direction by a reaction force generated in the movable portion pressed against the inner surface of the lens barrel by the urging means. The lens moving mechanism as described. The lens moving mechanism according to claim 3, wherein the lens holding frame is pressed against the guide shaft during movement in the optical axis direction by a reaction force generated in an elastic member pressed against the inner surface of the lens barrel. . The lens moving mechanism according to claim 4, wherein the pressing force of the lens holding frame against the guide shaft changes according to the position of the movable lens. The lens moving mechanism according to claim 5, wherein a pressing force of the lens holding frame against the guide shaft changes according to the position of the movable lens. The lens moving mechanism according to claim 6, wherein when the movable lens is for zooming, the pressing force of the lens holding frame against the guide shaft increases as the distance from the subject increases. 8. The lens moving mechanism according to claim 7, wherein when the movable lens is for zooming, the pressing force of the lens holding frame against the guide shaft increases as the distance from the subject increases. The lens moving mechanism according to claim 6, wherein when the movable lens is for focusing, the pressing force of the lens holding frame against the guide shaft increases as it approaches the subject. 8. The lens moving mechanism according to claim 7, wherein when the movable lens is used for focusing, the pressing force of the lens holding frame against the guide shaft increases as it approaches the subject. The lens moving mechanism according to claim 8, wherein an applied voltage to the driving unit is changed according to a position of the lens holding frame with respect to the guide shaft. The lens moving mechanism according to claim 9, wherein an applied voltage to the driving unit is changed according to a position of the lens holding frame with respect to the guide shaft. The lens moving mechanism according to claim 10, wherein an applied voltage to the driving unit is changed according to a position of the lens holding frame with respect to the guide shaft. The lens moving mechanism according to claim 11, wherein an applied voltage to the driving unit is changed in accordance with a position of the lens holding frame with respect to the guide shaft. A lens barrel having a movable lens for zooming or focusing disposed therein;
A lens holding frame that holds the movable lens inside the lens barrel and is supported movably in the optical axis direction of the movable lens;
A guide shaft for guiding the lens holding frame in the optical axis direction of the movable lens when the lens holding frame is moved;
Driving means for moving the lens holding frame in the optical axis direction of the movable lens,
The lens holding frame has a holding portion that holds the movable lens, and a movable portion that is provided on the outer peripheral portion of the holding portion and is operated with respect to the holding portion.
An imaging apparatus, wherein the movable part is operated with respect to the holding part in accordance with the movement of the lens holding frame in the optical axis direction so that the outer shape of the lens holding frame as viewed from the optical axis direction changes. A lens holding frame disposed inside the lens barrel and holding a movable lens for zooming or focusing, and supported movably in the optical axis direction of the movable lens;
A holding unit for holding the movable lens;
A movable part provided on the outer peripheral part of the holding part and operated with respect to the holding part,
A lens holding frame, wherein the movable portion is operated with respect to the holding portion in accordance with the movement in the optical axis direction so that the outer shape viewed from the optical axis direction changes.

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