JP2015141271A - Lens drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens drive device having a movable lens frame compatible with a space feature and suppression of shake.SOLUTION: A movable lens frame includes: a lens holding section for holding a lens to locate it in a fixed ring; a motor holding section that is located outside of the fixed ring and receives the driving power of a linear driving mechanism; and an arm section for connecting the lens holding section with the motor holding section. The arm section is configured by combining a body part made of a common material with the lens holding section and the motor holding section and a reinforcement part made of a material having larger elastic modulus than the body part.

Description

  The present invention relates to a lens driving device that constitutes an optical apparatus, and more particularly to a lens driving device that moves a lens forward and backward in an optical axis direction by a linear driving mechanism.

  In recent years, in the technical field of lens driving devices, a movable lens frame (for example, a focus lens frame) holding a movable lens (for example, a focus lens) is replaced with an optical axis by a linear motor (for example, a voice coil motor) instead of a driving mechanism using a stepping motor. It has been proposed to use a linear drive mechanism that moves forward and backward in the direction. The linear drive mechanism can move the movable lens frame forward and backward more quickly and quietly than a drive mechanism using a stepping motor.

JP 2011-203385 A

  A movable lens frame driven by a linear motor includes a lens holding unit that holds a lens, and a motor holding unit that holds a magnetic body, a coil, and the like constituting the linear motor. In the lens driving device, a linear motor may be disposed at a position away from the optical path where the optical system is located (position where the radial distance from the optical axis is large) due to space limitations. In this case, the movable lens frame is a lens. The holding part and the motor holding part are connected by a long arm part. In such a movable lens frame, as the lens held by the lens holding portion becomes heavier, the time until the blurring of the arm portion that occurs when the lens is driven at high speed by the linear motor becomes longer. Since shooting is performed after blurring converges, there is a problem that it takes time until shooting. In order to reduce blurring in the movable lens frame, measures to increase the rigidity by increasing the cross-sectional area of the arm can be considered, but overall space efficiency is ensured by ensuring space for the arm with a large cross-sectional area. This is not suitable for a lens driving device that is downsized.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a lens driving device including a movable lens frame that has excellent space characteristics and can suppress blurring.

  The present invention relates to a fixing member having a fixed ring for supporting a photographing optical system therein; a lens holding portion that holds a lens constituting the photographing optical system and is positioned in the fixed ring; and a motor holding that is positioned outside the fixed ring. And a movable lens frame having a lens holding portion and an arm portion connecting the motor holding portion; a coil and a magnetic body held on one and the other of the motor holding portion and the fixed member, and movable by energizing the coil A linear drive mechanism for driving the lens frame in the optical axis direction of the photographic optical system, wherein the arm part of the movable lens frame is made of a material common to the lens holding unit and the motor holding unit. And, it is characterized in that it is composed of a combination of reinforcing parts made of a material having a higher elastic modulus than the main body parts.

  The arm part forming part of the main body part has an inner diameter part connected to the lens holding part, an outer diameter part connected to the motor holding part, and an intermediate part connecting the inner diameter part and the outer diameter part. When viewed along the optical axis, the intermediate portion is narrower than the inner diameter portion and the outer diameter portion, and is positioned approximately at the center in the width direction of the inner diameter portion and the outer diameter portion. The reinforcing part has a pair of side parts along both sides of the intermediate part of the main body part, the lateral width combining the intermediate part of the main body part and the pair of side parts of the reinforcing part, the inner diameter part and the outer diameter of the main body part It is preferable that the horizontal widths of the parts are substantially the same.

  Moreover, it is preferable that the thickness of an intermediate part in a main body part and a pair of side part in a reinforcement part is the optical thickness direction substantially the same.

  In one form of the movable lens frame, the main body part and the reinforcing part are formed separately, and one end and the other end of the pair of side parts of the reinforcing part are fixed to the inner and outer diameter parts of the main body part by fixing means. Fix it.

  In another form of the movable lens frame, the main body part and the reinforcing part are formed separately, and the reinforcing part is provided with a bridging part that bridges one end of the pair of side parts. A fitting portion into which one end of the reinforcing part including the bridging portion is fitted is provided on either the inner diameter portion or the outer diameter portion of the main body part. And in the state which one end of a reinforcement part fits in this fitting part, the other end of a pair of side part in a reinforcement part is fixed with the fixing means with respect to the other of the internal diameter part of a main body part, and an outer diameter part. .

  In the movable lens frame of these forms, for example, an adhesive can be used as the fixing means for fixing the reinforcing part to the main body part.

  In yet another form of the movable lens frame, the reinforcing part has a pair of bridging portions that bridge one end and the other end of the pair of side portions, and a pair of the reinforcing parts are provided on the inner diameter portion and the outer diameter portion of the main body part. A pair of fitting portions for fitting one end and the other end of the reinforcing part including the bridging portion are provided.

  In the movable lens frame of this form, it is preferable that the main body part and the reinforcing part are integrally formed by insert molding.

  About the material which comprises a movable lens frame, it is preferable to form a main-body part with a polycarbonate and a reinforcement part with a fiber reinforced plastic.

  According to the present invention, the arm portion of the movable lens frame is configured by combining the main body part made of the same material as the lens holding portion and the motor holding portion and the reinforcing part having a higher elastic modulus than the main body part. The rigidity of the movable lens frame can be improved while suppressing the cross-sectional size, and a lens driving device that achieves both space characteristics and suppression of blurring can be obtained.

It is a front exploded perspective view of a lens barrel provided with a lens driving device to which the present invention is applied. It is a front exploded perspective view of a lens drive device. FIG. 3 is a rear exploded perspective view of the lens driving device. It is a front disassembled perspective view of the state which assembled some components of the lens drive device. It is a back disassembled perspective view of the state which assembled some components of the lens drive device. 1 is a front perspective view showing a focus lens frame of a first embodiment constituting a lens driving device. FIG. FIG. 3 is a front perspective view of main body parts constituting the focus lens frame of the first embodiment. FIG. 3 is a rear perspective view of the focus lens frame of the first embodiment. FIG. 3 is a rear perspective view of main body parts constituting the focus lens frame of the first embodiment. It is a front perspective view which shows the focus lens frame of 2nd Embodiment. It is the perspective view which looked at the main-body parts which comprise the focus lens frame of 2nd Embodiment from the angle different from FIG. It is a back perspective view of the focus lens frame of a 2nd embodiment. It is a back perspective view of the body parts which constitute the focus lens frame of a 2nd embodiment. It is a front perspective view which shows the reinforcement part in the focus lens frame of 2nd Embodiment. It is a front perspective view of the focus lens frame of 3rd Embodiment. It is the perspective view which looked at the main-body parts which comprise the focus lens frame of 3rd Embodiment from the angle different from FIG. It is a back perspective view of the focus lens frame of a 3rd embodiment. It is the perspective view which looked at the main-body parts which comprise the focus lens frame of 3rd Embodiment from the angle different from FIG. It is a front perspective view which shows the reinforcement part in the focus lens frame of 3rd Embodiment.

  The lens barrel 1 shown in FIG. 1 includes a fixed substrate 10 and a fixed ring 20 fixed to the fixed substrate 10 as fixing members. An image sensor 11 for forming a subject image formed by the photographing optical system of the lens barrel 1 is fixed to the fixed substrate 10. In the following description, in the direction along the optical axis O of the photographing optical system, the subject side is the front and the imaging plane side is the rear. In the radial direction around the optical axis O of the photographing optical system, the optical axis side is the inner diameter side, and the side far from the optical axis is the outer diameter side. The fixed ring 20 is a cylindrical body that surrounds the optical axis O of the photographing optical system, and has a central portion on the inner diameter side and an outer peripheral portion on the outer diameter side. The fixed substrate 10 is fixed to the rear end portion of the fixed ring 20.

  A feeding cylinder unit 30 is supported inside the fixed ring 20. The feeding cylinder unit 30 is capable of feeding (moving forward) and storing (moving backward) in the optical axis direction with respect to the stationary ring 20 in order from the outer peripheral side to the inner peripheral side. A second feeding cylinder 32 having a smaller diameter than the first feeding cylinder 31 and capable of feeding and storing in the optical axis direction with respect to the first feeding cylinder 31, and a second diameter with respect to the second feeding cylinder 32 having a smaller diameter than the second feeding cylinder 32. A third feeding cylinder 33 that can be fed and stored in the optical axis direction is supported. Such a multi-stage feeding type lens unit is well known and will not be described in detail. However, the first feeding cylinder 31, the second feeding cylinder 32, and the first feeding cylinder 31 are driven by the driving force of the motor supported by the fixed ring 20. The feeding and storing operation of the three feeding cylinder 33 is performed. FIG. 1 shows a state of the feeding cylinder unit 30 with the lens barrel 1 stored (collapsed), and the second feeding cylinder 32 and the third feeding cylinder 33 are housed inside the first feeding cylinder 31. Yes. Further, in the housed state, the entire feeding cylinder unit 30 including the first feeding cylinder 31 is housed inside the stationary ring 20. Although not shown, the first feeding cylinder 31 to the third feeding cylinder 33 support a plurality of lens groups (lens holding frames) constituting the photographing optical system of the lens barrel 1, and the first feeding cylinder 31 to the third feeding cylinder 33 are supported. Zooming is performed by moving the cylinder 31 to the third feeding cylinder 33 in the optical axis direction and changing the positions in the optical axis direction of the plurality of lens groups (lens holding frames).

  A focus lens frame (movable lens frame) 40 holding a focus lens FL shown in FIG. 2 and subsequent figures is supported on the fixed substrate 10 and the fixed ring 20 so as to be movable back and forth in the optical axis direction. Yes. The focus lens FL is a lens group that constitutes the photographing optical system of the lens barrel 1 together with the lens group in the feeding cylinder unit 30, and is located behind the lens group supported in the feeding cylinder unit 30.

  A structure for supporting and driving the focus lens frame 40 will be described. The holder 12 shown in FIGS. 2 to 5 is fixed to the fixed substrate 10 and the fixed ring 20. The holder 12 has a rear wall 12a facing the fixed substrate 10 and a front projecting wall 12b having an L-shaped section projecting forward from the rear wall 12a, and a long hole in the optical axis direction in the front projecting wall 12b. A support hole 12c is formed. The front protruding wall 12b is positioned outside the fixed ring 20 in the radial direction centered on the optical axis O, and the retaining member 13 is fixed to the front end portion of the front protruding wall 12b. Two guide shafts 14, 15 extending in the optical axis direction are fixed to the rear wall 12 a of the holder 12 and the retaining member 13, respectively.

  The focus lens frame 40 includes a cylindrical lens holding portion 41 that holds the focus lens FL, a radial arm portion 42 that extends in the radial direction from the lens holding portion 41, and a motor holding portion that is located at the tip of the radial arm portion 42. 43. The motor holding portion 43 has a guide hole 44 slidably fitted to the guide shaft 14, a guide groove 45 slidably engaged with the guide shaft 15, a through hole 46 in the optical axis direction, and a through hole A coil support protrusion 47 protruding forward from the vicinity of 46 is formed.

  The focus lens frame 40 is supported so as to be linearly movable in the optical axis direction when the guide hole 44 and the guide groove 45 are guided by the guide shafts 14 and 15. Two guide holes 44 are formed at different positions in the optical axis direction, and regulate the inclination of the focus lens frame 40 with respect to the guide shaft 14. The guide groove 45 is formed by a bifurcated portion that opens at the outer edge of the motor holding portion 43, and the rotation of the focus lens frame 40 around the guide shaft 14 is restricted by the engagement of the guide shaft 15 and the guide groove 45. .

  The guide shafts 14 and 15 are arranged outside the fixed ring 20, and the motor holding portion 43 of the focus lens frame 40 that receives the straight guide by the guide shafts 14 and 15 is also located outside the fixed ring 20. In order to show this relationship, a part of the outer shape of the stationary ring 20 is shown in phantom lines in FIG. A slit 21 that penetrates in the radial direction and is long in the optical axis direction is formed in the fixed ring 20 (FIG. 1), and a radial arm portion 42 of the focus lens frame 40 is inserted into the slit 21. When the focus lens frame 40 moves in the optical axis direction, the radial arm portion 42 moves along the slit 21.

  A coil 60 constituting a linear drive mechanism is fitted and supported on a coil support protrusion 47 of the focus lens frame 40. The coil 60 is a flat air-core coil with the winding center in the direction parallel to the optical axis O, and the air-core portion of the coil 60 is connected to the through hole 46 in a state where the coil 60 is fitted and supported by the coil support protrusion 47. Overlapping positions. The coil 60 is energized and controlled via the flexible substrate 61.

  A magnet unit (magnetic body) 65 that constitutes a linear drive mechanism together with the coil 60 is fixed to the holder 12. The magnet unit 65 includes a pair of yokes 66 and 67 and a permanent magnet 68, and is fitted and supported in the support hole 12 c of the holder 12. The yoke 66 has a longitudinal wall that is long in the optical axis direction, and a pair of short-side walls that are formed at the front and rear ends of the longitudinal wall and are substantially orthogonal to the longitudinal wall. A pair of short-side walls of the yoke 66 are bridged by a yoke 67, and the yoke 66 and the yoke 67 are coupled so as to draw a box-shaped closed section. The permanent magnet 68 has a thin rectangular parallelepiped shape fixed on the longitudinal wall of the yoke 66. The yoke 67 is inserted through the through hole 46 of the focus lens frame 40 and the air core of the coil 60 in a non-contact manner. A yoke 67 and a coil 60 in the magnetic field of the permanent magnet 68 constitute a voice coil motor. When the coil 60 is energized in the forward and reverse directions, an electromagnetic driving force is generated. The lens FL) moves along the guide shafts 14 and 15 in the optical axis direction.

  When the focus lens frame 40 moves back and forth in the optical axis direction by the linear drive mechanism, the position detection sensor 69 fixed to the front protruding wall 12b of the holder 12 receives the magnetic fluxes of the pair of yokes 66 and 67 and the permanent magnet 68. By converting this magnetic flux change into an output voltage, the position of the focus lens frame 40 in the optical axis direction can be detected.

  In the lens barrel 1, the focus lens FL is positioned on the optical axis O in the radial direction centered on the optical axis O of the photographing optical system, while the guide shafts 14 and 15 are separated from the optical axis. It is located outside. Therefore, in the focus lens frame 40, the radial arm portion 42 that connects the lens holding portion 41 that holds the focus lens FL and the motor holding portion 43 that receives the guidance by the guide shafts 14 and 15 is long. The focus lens frame 40 has a structure that increases the strength (rigidity) of the radial arm portion 42 and suppresses vibrations when driven at a high speed by a linear drive mechanism.

  2 to 9 show the focus lens frame 40 in the first embodiment. The focus lens frame 40 is configured by combining a main body part 49 and a reinforcing part 50. 7 and 9 show the configuration of the main body part 49 alone, in which the reinforcing part 50 is not assembled. The main body part 49 includes a radially inner portion 49a connected to the lens holding portion 41, an outer diameter portion 49b connected to the motor holding portion 43, and an inner diameter portion 49a. It has an intermediate portion 49c that connects the outer diameter portion 49b. When the main body part 49 is viewed in front (or rear view) along the optical axis direction, the inner diameter portion 49a and the outer diameter portion 49b are substantially the same width, and the intermediate portion 49c is wider than the inner diameter portion 49a and the outer diameter portion 49b. It is narrowed. The intermediate portion 49c is formed at a substantially center in the width direction of the radial arm portion 42, and fitting spaces S are formed on both sides of the intermediate portion 49c. The intermediate portion 49c protrudes (offset) rearward in the optical axis direction with respect to the inner diameter portion 49a, and a bent step portion 49d is formed between the inner diameter portion 49a and the intermediate portion 49c. A support surface 49e is formed on the rear surface side of the inner diameter portion 49a adjacent to the step portion 49d (see FIG. 9). Further, the intermediate portion 49 c protrudes (offset) rearward in the optical axis direction with respect to the motor holding portion 43, and the outer diameter portion 49 b that connects the intermediate portion 49 c and the motor holding portion 43 is separated from the motor holding portion 43. As it approaches the intermediate portion 49c, it has an inclined shape protruding in the optical axis direction.

  In the middle of the inner diameter portion 49a, a step portion 49f for offsetting the radial arm portion 42 from the lens holding portion 41 to the rear in the optical axis direction as a whole is formed. The offset shape of the radial arm portion 42 by the step portion 49f is for increasing the space efficiency by bringing a part of the feeding cylinder unit 30 close to the front side of the radial arm portion 42 in the retracted state of the lens barrel 1. It is. However, the present invention can also be applied to a configuration in which the inner diameter portion 49a has a straight shape without the stepped portion 49f.

  The reinforcing part 50 has a U-shaped shape including a pair of side portions 51 and a bridging portion 52 that bridges one end portions of the pair of side portions 51 (see FIGS. 2 and 3). ), The pair of side portions 51 and the bridging portion 52 are located on the same plane. In the longitudinal direction of the reinforcing part 50 (extending direction of the side portion 51), the end portion on the side having the bridging portion 52 is defined as the inner diameter side end portion, and the opposite end portion is defined as the outer diameter side end portion.

  As shown in FIGS. 6 and 8, the reinforcing part 50 is combined with the main body part 49 by fitting a pair of side parts 51 into the fitting spaces S on both sides of the intermediate part 49 c. In this combined state, the pair of side portions 51 sandwich the intermediate portion 49c, the U-shaped inner diameter side end portion including the pair of side portions 51 and the bridging portion 52 is fitted to the stepped portion 49d, and The outer diameter side end of the side portion 51 contacts the outer diameter portion 49b, and the bridging portion 52 contacts the support surface 49e on the rear surface side of the inner diameter portion 49a, thereby determining the position of the reinforcing part 50 relative to the main body part 49. . Then, as shown in FIG. 6, a total of four locations near the inner diameter side end portion and the outer diameter side end portion of the reinforcing part 50 are bonded to the inner diameter portion 49a and the outer diameter portion 49b of the main body part 49 with an adhesive 55. The reinforcing part 50 is fixed to the main body part 49 by bonding.

  The lateral width of the reinforcing part 50 (the distance between the outer side surfaces of the pair of side portions 51) is substantially the same as the lateral width of the inner diameter portion 49a and the outer diameter portion 49b of the main body part 49. When viewed from the front (or back) along the optical axis direction, the entire radial arm portion 42 has the same width. The thickness of the reinforcing part 50 in the optical axis direction is substantially the same as the thickness of the intermediate part 49 c of the main body part 49. Therefore, when the radial arm portion 42 is viewed from the side, the reinforcing part 50 does not protrude in the front-rear direction with respect to the intermediate portion 49 c of the radial arm portion 42. Accordingly, the radial arm portion 42 is configured by extending the inner diameter portion 49 a and the outer diameter portion 49 b without combining the reinforcing part 50, while configuring the radial arm portion 42 by combining the reinforcing part 50 with the main body part 49. The focus lens frame 40 can be configured without affecting the space efficiency around the radial arm portion 42 because the cross-sectional sizes are about the same. In particular, when the lens drive 1 is stored, the components of the feeding cylinder unit 30 and the fixed substrate 10 are close to the focus lens frame 40, but the reinforcing part 50 does not interfere with these adjacent elements and is compact. The lens barrel storage state can be realized.

The reinforcing part 50 is formed of a material having a higher elastic modulus (high rigidity) than the material constituting the main body part 49 of the focus lens frame 40, and when the cross-sectional size of the radial arm 42 is constant, the main body The strength of the radial arm 42 is improved by combining the reinforcing part 50 rather than configuring the radial arm 42 by only the part 49. Specifically, the material of the main body part 49 is preferably an engineering plastic such as polycarbonate that has been widely used in the field of lens holding frames in terms of productivity and cost. Then, by selecting a fiber reinforced plastic such as carbon fiber reinforced plastic or glass fiber reinforced plastic as the material of the reinforcing part 50, it is possible to obtain a structure having excellent strength while being lightweight and space saving. As an example, a focus lens frame (having the same shape as the focus lens frame 40) integrally formed of polycarbonate with a specific gravity of 1.35 g / cm ³ and a Young's modulus of 5.5 GPa, and a body part 49 made of equivalent polycarbonate and a specific gravity of 1.56 When compared with the focus lens frame 40 of the illustrated embodiment composed of the reinforcing parts 50 made of carbon fiber reinforced plastic with g / cm ³ and Young's modulus of 144 GPa, the former resonance frequency is 254.7 Hz and the latter resonance frequency is 343.9 Hz. As a result, a significant increase in rigidity was achieved with almost the same weight.

The material of the reinforcing part 50 can be selected other than the fiber reinforced plastic. However, in the case of a metal having a large specific gravity, the focus lens frame 40 may be heavy and adversely affect the operation performance. It is preferable to use a material having a specific gravity that does not greatly exceed the part 49. For example, stainless steel (SUS304) with a specific gravity of 7.9 g / cm ³ and Young's modulus of 199 GPa is superior in strength, but has a much higher specific gravity than polycarbonate or fiber reinforced plastic, which increases the burden on the linear drive mechanism. End up.

  As described above, the focus lens frame 40 in which the rigidity of the radial arm portion 42 is increased by the reinforcing part 50 is suppressed from blurring (vibration) when moved at high speed by the linear drive mechanism, and the performance of the lens barrel 1 is improved. Contribute to. Specifically, the time until the blur of the focus lens frame 40 converges during the focusing operation is shortened, and the shooting speed can be increased. In particular, the focus lens frame 40 of the present embodiment has a long radial arm portion 42 for connecting the lens holding portion 41 located at the center portion of the fixed ring 20 and the motor holding portion 43 located outside the fixed ring 20. In addition, since it has a cantilever structure in which the heavy focus lens FL is held at one end portion (lens holding portion 41) of the radial arm portion 42, the radial arm portion 42 is likely to be blurred. Therefore, it is particularly effective to suppress the blur by increasing the rigidity by combining the reinforcing parts 50.

  Unlike the focus lens frame 40 of this embodiment, it is possible to increase the rigidity by increasing the cross-sectional size of the radial arm portion 42 without using the reinforcing part 50. However, this configuration has a problem that the space around the focus lens frame 40 is deteriorated. As described above, in the lens barrel 1 of the present embodiment, since other components are arranged at positions close to the radial arm portion 42 in the stored state, when the cross-sectional size of the radial arm portion 42 is increased, the lens barrel 1 is stored. This will affect the space efficiency of the entire lens barrel 1 at that time. On the other hand, in the focus lens frame 40 of the present embodiment in which the reinforcing part 50 is combined with the main body part 49 to form the radial arm part 42, by selecting an appropriate material for the reinforcing part 50, It is possible to ensure a predetermined rigidity without increasing the cross-sectional size.

  10 to 13 show the focus lens frame 140 in the second embodiment. The focus lens frame 140 is configured by combining the main body part 49 and the reinforcing part 150 as in the first embodiment, and the configuration of the assembly part of the reinforcing part 150 with respect to the main body part 49 is different from that of the first embodiment. In FIG. 10 and subsequent figures, portions common to the first embodiment are denoted by common reference numerals and description thereof is omitted.

  As shown in FIGS. 11 and 13, an inner diameter side fitting portion 49g is provided at the boundary portion between the inner diameter portion 49a and the intermediate portion 49c of the main body part 49 instead of the stepped portion 49d and the support surface 49e of the first embodiment. Is formed. The inner diameter side fitting portion 49g has an abutting surface 49g-1 facing the outer diameter direction, and a hook-shaped abutting surface 49g-2 that faces the front of the intermediate portion 49c in the optical axis direction. . The contact surface 49g-1 and the contact surface 49g-2 are formed as a part of the inner diameter portion 49a and have the same width as the other portions of the inner diameter portion 49a.

  As shown in FIG. 4, the reinforcing part 150 bridges a pair of side sides 151 along the fitting spaces S (FIGS. 11 and 13) on both sides of the intermediate portion 49 c and one end of the pair of side sides 151. It has a U-shape formed of a bridging portion 152 that is entangled. Unlike the bridging portion 52 of the first embodiment, the bridging portion 152 bridges the front surfaces (surfaces facing forward in the optical axis direction) of the pair of side portions 151, with respect to each side portion 151. The bridging part 152 has a stepped shape protruding forward in the optical axis direction. The reinforcing part 150 is formed of a material that satisfies the same conditions as the reinforcing part 50 of the first embodiment.

  As shown in FIGS. 10 and 12, the pair of side portions 151 of the reinforcing part 150 fit into the fitting spaces S on both sides of the intermediate portion 49 c of the main body part 49. The inner diameter side end portion of the reinforcing part 150 applies each side portion 151 and the bridging portion 152 to the abutting surface 49g-1, and the bridging portion 152 between the abutting surface 49g-2 and the intermediate portion 49c. It is inserted and fitted to the inner diameter side fitting portion 49g. By this fitting, the position of the reinforcing part 150 with respect to the main body part 49 is determined. As in the first embodiment, the outer diameter side end portion of the reinforcing part 150 is in contact with the outer diameter portion 49b of the main body part 49 at the ends of the pair of side portions 151, as shown in FIG. The vicinity of the contact portion is fixed to the main body part 49 using the adhesive 56. Thus, the focus lens frame 140 composed of the main body part 49 and the reinforcing part 150 is completed. Since the inner diameter side end of the reinforcing part 150 is assembled to the main body part 49 by fitting, the structure is excellent in productivity because there are few adhesion points.

  15 to 19 show a focus lens frame 240 according to the third embodiment. The focus lens frame 240 includes a main body part 49 and a reinforcing part 250. The configuration of the inner diameter side fitting portion 49g of the main body part 49 is the same as that of the second embodiment. Further, the second embodiment is different from the second embodiment in that an outer diameter side fitting portion 49h is also formed at a boundary portion between the outer diameter portion 49b and the intermediate portion 49c in the main body part 49. The outer diameter side fitting portion 49h has a contact surface 49h-1 facing the inner diameter direction, and a hook-shaped contact surface 49h-2 that faces the front of the intermediate portion 49c in the optical axis direction. . The contact surface 49h-1 and the contact surface 49h-2 are formed as part of the outer diameter portion 49b and have the same width as the other portions of the outer diameter portion 49b.

  As shown in FIG. 19, the reinforcing part 250 is formed by bridging the front surface (surface facing forward in the optical axis direction) of the inner diameter side ends of the pair of side portions 251 with the bridging portion 252. This is a configuration in which the front surface (surface facing forward in the optical axis direction) of the outer diameter side end portion of the side portion 251 is bridged by a bridging portion 253. As shown in FIGS. 15 and 17, the pair of side portions 251 of the reinforcing part 250 has a shape that fits in the fitting spaces S (FIGS. 16 and 18) on both sides of the intermediate portion 49 c of the radial arm portion 42. ing. The inner diameter side end portion of the reinforcing part 250 applies the side portions 251 and the bridging portion 252 to the abutting surface 49g-1, and the bridging portion 252 between the abutting surface 49g-2 and the intermediate portion 49c. It has a shape to be inserted and fitted into the inner diameter side fitting portion 49g. The outer diameter side end portion of the reinforcing part 250 applies the side portions 251 and the bridging portion 253 to the abutment surface 49h-1, and the bridging portion 253 between the abutment surface 49h-2 and the intermediate portion 49c. And is fitted into the outer diameter side fitting portion 49h. When the reinforcing part 250 having such a both-end fitting structure is formed of a material having a high elastic modulus such as a fiber reinforced plastic, the reinforcing part 250 is elastically deformed so that the inner diameter side fitting part 49g and the outer diameter side fitting part 49h. Therefore, it is preferable to form the reinforcing part 250 together with the main body part 49 by insert molding. In the insert molding, a completed state of the focus lens frame 240 as shown in FIGS. 15 and 17 can be obtained without performing a fixing operation in a subsequent process with an adhesive or the like.

  The focus lens frame 140 according to the second embodiment and the focus lens frame 240 according to the third embodiment are the focus lenses according to the first embodiment except for the structure where the reinforcing part 150 and the reinforcing part 250 are coupled to the main body part 49. It is common with the frame 40, and the effects described above with respect to the focus lens frame 40 can also be obtained in the focus lens frame 140 and the focus lens frame 240.

  As mentioned above, although demonstrated based on illustration embodiment, this invention is not limited to illustration embodiment. As the proportion of the reinforcing parts in the cross-sectional area of the radial arm portion 42 increases, the rigidity becomes higher. Therefore, as shown in the illustrated embodiment, both sides of the intermediate portion 49c of the main body part 49 are connected to a pair of the reinforcing parts 50, 150, and 250. The structure sandwiched between the side portions 51, 151, and 251 is advantageous in terms of improving rigidity. This structure is also excellent in terms of ease of manufacture. However, unlike the configuration of the illustrated embodiment, the main body part 49 is formed so that the slit is inserted in the intermediate position in the width direction of the radial arm portion 42, and the reinforcing part is used that is fitted (embedded) in the slit. It is also possible. Further, the radial arm portion 42 of the illustrated embodiment has a flat shape with a small thickness in the optical axis direction with respect to the lateral width when viewed from the front, and has a structure in which the main body part 49 and the main body part 50 are stacked in the optical axis orthogonal direction. However, when applied to a radial arm portion having a predetermined thickness or more in the optical axis direction, it is possible to change to a configuration in which the main body part and the reinforcing part are stacked in the optical axis direction.

  In the illustrated embodiment, the coil 60 held by the motor holding portion 43 of the focus lens frame 40 and the magnet unit 65 held on the holder 12 side constitute a linear drive mechanism. However, the present invention can be applied to a configuration in which a magnet unit is held on the focus lens frame 40 and a coil is held on the holder 12 side.

FL Focus lens S Fitting space 10 Fixed substrate (fixed member)
11 Image sensor 12 Holder (fixing member)
12a Rear wall 12b Front projecting wall 12c Support hole 13 Stopping member 14 15 Guide shaft 20 Fixed ring (fixing member)
21 Slit 30 Feeding cylinder unit 31 1st feeding cylinder 32 2nd feeding cylinder 33 3rd feeding cylinder 40 140 240 Focus lens frame (movable lens frame)
41 Lens holding portion 42 Radial arm portion 43 Motor holding portion 44 Guide hole 45 Guide groove 46 Through hole 47 Coil support protrusion 49 Main body part 49a Inner diameter portion 49b Outer diameter portion 49c Intermediate portion 49d Step portion 49e Support surface 49f Step portion 49g Inner diameter Side fitting portion 49g-1 49g-2 Contact surface 49h Outer diameter side fitting portion 49h-1 49h-2 Contact surface 50 150 250 Reinforcement part 51 151 251 Side side portion 52 152 252 253 Bridge portion 55 56 Adhesion Agent 60 Coil (Linear drive mechanism)
61 Flexible substrate 65 Magnet unit (linear drive mechanism, magnetic body)
66 67 Yoke 68 Permanent magnet 69 Position detection sensor

Claims (9)

A fixing member having a fixing ring for supporting the photographing optical system inside;
A lens holding part that holds the lens constituting the photographing optical system and is located in the fixed ring, a motor holding part that is located outside the fixed ring, and an arm that connects the lens holding part and the motor holding part A movable lens frame having a portion;
A linear drive mechanism having a coil and a magnetic body held by one and the other of the motor holding portion and the fixing member, and driving the movable lens frame in the optical axis direction of the photographing optical system by energizing the coil;
With
The arm part of the movable lens frame is configured by combining a body part made of a material common to the lens holding part and the motor holding part, and a reinforcing part made of a material having a higher elastic modulus than the body part. A lens driving device. The lens driving device according to claim 1,
The arm part forming part of the main body part has an inner diameter part connected to the lens holding part, an outer diameter part connected to the motor holding part, and an intermediate part connecting the inner diameter part and the outer diameter part. When viewed along the optical axis of the photographing optical system, the intermediate portion is narrower than the inner diameter portion and the outer diameter portion and is positioned at the approximate center in the width direction of the inner diameter portion and the outer diameter portion. And
The reinforcing part has a pair of side parts along both sides of the intermediate part,
A lens driving device in which the lateral width of the intermediate portion and the pair of side portions is substantially the same as the lateral width of the inner diameter portion and the outer diameter portion. The lens driving device according to claim 2, wherein the intermediate portion and the pair of side portions have substantially the same thickness in the optical axis direction. 4. The lens driving device according to claim 2, wherein the main body part and the reinforcing part are formed separately, and one end and the other end of the pair of side sides are fixed to the inner diameter part and the outer diameter part. Lens drive device fixed by means. The lens driving device according to claim 2 or 3, wherein the main body part and the reinforcing part are formed separately.
The reinforcing part has a bridging portion that bridges one end of the pair of side portions,
One of the inner diameter part and the outer diameter part of the main body part has a fitting part into which one end of the reinforcing part including the bridging part is fitted,
A lens driving device in which the other end of the pair of side portions is fixed to the other of the inner diameter portion and the outer diameter portion by a fixing means. 6. The lens driving device according to claim 4, wherein the fixing means is an adhesive. The lens driving device according to claim 2 or 3,
The reinforcing part has a pair of bridging portions that bridge one end and the other end of the pair of side portions,
A lens driving device having a pair of fitting portions for fitting one end and the other end of the reinforcing part including the pair of bridging portions to the inner diameter portion and the outer diameter portion of the main body part. 8. The lens driving device according to claim 7, wherein the main body part and the reinforcing part are integrally formed by insert molding. 9. The lens driving device according to claim 1, wherein the main body part is made of polycarbonate, and the reinforcing part is made of fiber reinforced plastic.

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