JP2005257835A - Optical module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical module having the high flexibility in terms of arrangement. <P>SOLUTION: The optical module is equipped with a stepping motor 28, a lens barrel (optical parts) 26 whose outer periphery is formed to be circular, a moving means 27 moving the lens barrel along its optical axis O, a reduction gear train 29 interlocking the moving means 27 with the motor 28, and a base 23 which is formed circularly when viewed two-dimensionally and where the motor 28, the lens barrel 26, the moving means 27 and the gear train 29 are arranged inside from its periphery 23a. The motor 28 is equipped with a coil block 45 having an exciting coil 49, a yoke 46 provided with magnetic path parts 46X, 46Y and 46Z other than ends 46b and 46c coupled with the block 45 without being overlapped on the block 45, and a rotor 47 arranged at the rotor hole 50 of the yoke 46. The lens barrel 26 is arranged at the center part of the base 23, and the motor 28 is arranged concentrically with the lens barrel 26. The moving means 27 and the gear train 29 are arranged along the outer periphery of the lens barrel 26 when seen two-dimensionally. Thus, a lens driving device (optical module) 21 is made circular in plan view. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical module that is mounted on a thin electronic device such as a card-type digital camera or a camera-equipped mobile phone and includes an optical component that is moved for focus adjustment, zooming, and the like.

  Conventionally, in order to adjust the focus by moving a lens barrel that holds a lens, a drive shaft of a cylindrical stepping motor is formed by a feed screw, and the feed screw protrudes from a lens barrel holder that supports the lens barrel. A lens driving device (optical module) is known that engages the rack member and moves the lens barrel along the optical axis via the rack member in accordance with the forward / reverse rotation of the stepping motor to perform the focusing operation. (For example, refer to Patent Document 1).

  In addition, as in Patent Document 1, the cylindrical stepping motor is not arranged around the lens barrel as a so-called vertical installation in which the axis is parallel to the optical axis. It has also been proposed to arrange in a so-called horizontal orientation, which is arranged in a relationship orthogonal to (see FIGS. 11 and 12).

  That is, between the rectangular base indicated by reference numeral 1 in FIG. 11 and FIG. 12 and the cover indicated by reference numeral 2, it can move along a plurality of guides 3 extending over them and is biased by the coil spring 3 a. A lens barrel holder 4 is disposed, and a lens barrel 5 having a plurality of lenses is held in the holder 4. A circuit board 7 on which an image sensor 6 is mounted is attached to the base 1 so as to face the lens barrel 5. A cylindrical stepping motor 8 is attached to the base 1 so as to be detached from the lens barrel holder 4. The stepping motor 8 is provided horizontally with its drive shaft 8a parallel to the plate surface of the base 1, and a worm 9 is fixed to the drive shaft 8a. The feed screw 10 provided over the base 1 and the cover 2 passes through the outwardly projecting portion 4 a of the lens barrel holder 4, and the worm wheel 11 fixed to the feed screw 10 is engaged with the worm 9. A nut member 12 is fixed to the outward projecting portion 4 a, and the nut member 12 is engaged with the feed screw 10.

Accordingly, by driving the stepping motor 8, the rotational power is decelerated through the war gear (worm 9 and worm wheel 11) and the transmission direction is converted by 90 ° and transmitted to the feed screw 10. Based on the rotation of the screw 10 and the engagement of the nut member 12, the lens barrel 5 can be moved along the optical axis via the lens barrel holder 4, thereby performing a focusing operation.
JP-A-3-294809 (page 2, upper right column, line 19-same page, lower left column, line 6; page 3, lower right column, line 5-page 6, upper left column, line 1; and FIG. 1-FIG. (Fig. 3)

  In an optical module in which a cylindrical stepping motor is arranged vertically as in Patent Document 1, and the optical module is arranged around the optical axis of the lens barrel, the projection is viewed from the lens barrel. The position where the cylindrical stepping motor as a part is arranged changes. Due to this change, the cylindrical stepping motor may interfere with components arranged around the optical module. Thus, it is difficult to arrange the optical module by freely selecting its orientation because of the relationship with surrounding components. It should be noted that it is possible to obtain the degree of freedom of the orientation of the optical module if the peripheral components are arranged so as to avoid the movement trajectory of the cylindrical stepping motor when the optical module goes around the optical axis of the lens barrel. However, in this case, peripheral components cannot be arranged in the movement locus, which is not preferable for reducing the size of the device equipped with the optical module.

  In the optical module shown in FIGS. 11 and 12, even if the rectangular base on which the lens barrel and the horizontal cylindrical stepping motor are arranged is a square, for example, the optical module is rotated around the center of the base. When trying to arrange, the position where each corner of the base is arranged changes. This change may cause each corner of the base to interfere with parts arranged around the optical module. Thus, it is difficult to freely select and arrange the orientation of the optical module because of the relationship with surrounding components. It is possible to obtain the degree of freedom of the orientation of the optical module if the surrounding parts are arranged avoiding the movement trajectory of each corner of the base when the optical module is turned around the optical axis of the lens barrel. is there. However, in this case, peripheral components cannot be arranged in the movement locus, which is not preferable for reducing the size of the device equipped with the optical module.

  An object of the present invention is to provide an optical module having a high degree of freedom in arrangement.

  In order to solve the above-described problems, the present invention provides an optical device having a stepper motor and an optical axis extending in the axial direction, the outer periphery of which is formed in a circular shape on the inner side of the periphery of a base that is circular when viewed in plan. A component, a moving unit that moves the optical component along the optical axis, and a reduction gear train that links the moving unit and the rotor of the stepping motor are arranged.

  In the present invention, the optical module can be substantially circular in plan view by the arrangement of the stepping motor, the optical component, the moving means, and the reduction gear train with respect to the base. Thereby, even if the optical module is rotated around the optical axis of the optical component, it can be suppressed that the module interferes with the peripheral component.

  In order to solve the above-described problems, the present invention provides a coil block having an exciting coil, a yoke provided with a magnetic path portion other than the end connected to the block without overlapping the coil block, and this A stepping motor having a rotor disposed in the rotor through-hole of the yoke; an optical component having an optical axis extending in the axial direction and having a circular outer periphery; and moving the optical component along the optical axis A moving means, a reduction gear train that interlocks the moving means and the rotor, and a circular shape when seen in a plan view, and the stepping motor, the optical component, the moving means, and the reduction gear train are arranged inside the periphery. And the optical component is arranged at the center of the base, and the optical axis of the optical component is shared so that the stepping motor is concentrically with the optical component. And location, and, in which are arranged along the outer periphery of the optical component watching the moving means and the reduction gear train in a plane.

  In the present invention, the arrangement of the stepping motor, the moving means, and the reduction gear train with respect to the optical component having a circular outer periphery arranged at the center of the base as well as the arrangement of the stepping motor, the optical component, the moving means, and the reduction gear train with respect to the base. Thus, the optical module can be made substantially circular in plan view. Thereby, even if the optical module is rotated around the optical axis of the optical component, it can be suppressed that the module interferes with the peripheral component.

  In order to solve the above-described problems, the present invention provides a coil block having an exciting coil, a yoke provided with a magnetic path portion other than the end connected to the block without overlapping the coil block, and this A stepping motor having a rotor disposed in the rotor through-hole of the yoke; an optical component having an optical axis extending in the axial direction and having a circular outer periphery; and moving the optical component along the optical axis A moving means, a reduction gear train that interlocks the moving means and the rotor, and a circular shape when seen in a plan view, and the stepping motor, the optical component, the moving means, and the reduction gear train are arranged inside the periphery. The optical component is disposed at the center of the base, and the coil block and the yoke connected to each other in a ring shape are viewed in plan view. Arranged along the outer periphery of the optical component, the rotor, the moving means, and the reduction gear train are removed from between the coil block and the optical component and arranged along the outer periphery of the optical component in plan view. Is.

  According to the present invention, a coil block, a yoke, a rotor, a moving means, and a reduction gear for an optical component having a circular outer periphery arranged at the center of the base, together with the arrangement of the stepping motor, the optical component, the moving means, and the reduction gear train with respect to the base Depending on the arrangement of the gear train, the optical module can be substantially circular in plan view. Thereby, even if the optical module is rotated around the optical axis of the optical component, it can be suppressed that the module interferes with the peripheral component.

  In a preferred embodiment of the present invention, the coil block is bent along the outer periphery of the optical component in plan view. That is, the coil block is approximated to an arc shape. Accordingly, the annular shape formed by the coil block and the yoke can be approximated to a more circular shape, which is suitable for making the planar shape of the optical module circular.

  In a preferred embodiment of the present invention, the rotor, the moving means, and the reduction gear train are arranged on the opposite side of the coil block with the optical component as a boundary. As a result, guides that guide the movement of the optical components are provided between the rotor, the moving means, the reduction gear train, and the coil block, avoiding interference with the rotor, the moving means, the reduction gear train, and the coil block. Can do.

  Further, in a preferred embodiment of the present invention, the optical component, the moving means, and the reduction gear train are arranged in an inner periphery of the outer periphery of the coil block and the yoke that are connected to each other in an annular shape. . As a result, when the optical module is viewed in plan, the moving means, the reduction gear train, and the like do not protrude outward, so that even if the optical module is rotated around the optical axis of the optical component, the module interferes with surrounding components. Can be suppressed more reliably.

  In a preferred embodiment of the present invention, the coil block and the yoke connected in an annular shape are provided symmetrically with respect to a straight line passing through the axis of the rotor and the optical axis. This line-symmetric arrangement improves the weight balance of the optical module and improves the magnetic balance as the length of the magnetic path portion extending between the coil block and the rotor through hole becomes the same.

  In a preferred embodiment of the present invention, the exciting coil is provided between the first and second yoke connecting portions located at both ends of the coil block and the third yoke connecting portion located at the center. The yoke has first and second magnetic path portions with one end individually connected to the first and second yoke connecting portions and the other end facing the rotor through-hole, and the first and second And a ring-shaped third magnetic path portion with one end connected to the third yoke connecting portion and the other end facing the rotor through hole, A gap is provided between the magnetic path portion and the first magnetic path portion and the second magnetic path portion. As a result, an arrangement space for the components used facing the optical components is secured inside the third magnetic path portion for guiding the magnetic flux from the third yoke coupling portion of the coil block to the rotor through hole. The parts used opposite to the optical parts can be arranged.

  In a preferred embodiment of the present invention, a guide for guiding the movement of the optical component is disposed through the gap. In a preferred embodiment of the present invention, a through hole is provided in the magnetic path portion of the yoke, and a guide for guiding the movement of the optical component is passed through the through hole. According to the embodiments of the present invention, the guide is disposed inside the outer periphery of the coil block and the yoke that are connected to each other to form an annular shape so that the guide does not protrude outward when the optical module is viewed in plan.

  In a preferred embodiment of the present invention, a gear shaft included in the reduction gear train is disposed through the gap. In a preferred embodiment of the present invention, a through hole is provided in the magnetic path portion of the yoke, and a gear shaft included in the reduction gear train is passed through the through hole. According to these aspects of the invention, at least a part of the gear fixed to the gear shaft can be disposed so as to overlap the stepping motor.

  In a preferred embodiment of the present invention, a sensor for detecting the amount of movement of the optical component along the optical axis is provided, and the sensor is arranged inside the outer periphery of the coil block and the yoke connected to each other in an annular shape. ing. Thereby, the optical module including the sensor can be substantially circular in a plan view, and even when the optical module is rotated around the optical axis of the optical component, the module can be prevented from interfering with the peripheral components.

  Since the optical module according to the present invention has a substantially circular shape in plan view, interference with surrounding components is suppressed even when the optical axis of the optical component is rotated, and the degree of freedom in arrangement is high.

  A first embodiment of the present invention will be described with reference to FIGS.

  An optical module, for example, a lens driving device indicated by reference numeral 21 in FIG. 1 and FIG. The lens driving device 21 includes a base 23 having a circuit board 22 mounted on one surface, a gear support 24, a cover 25, optical components such as a lens barrel 26, a moving means 27, a stepping motor 28, and a reduction gear train. 29.

  As shown in FIG. 1, the base 23 made of an electrical insulating material is a flat plate having a circular shape. A circuit board 22 is mounted on the entire surface of the central portion of the base 23. An image sensor 30 such as a CCD or CMOS is mounted on the surface of the circuit board 22. On the base 23, a gear support 24 facing the base 23 with a predetermined distance is disposed. As shown in FIG. 6, the gear support 24 has a bent shape, and has a through hole 24a in the middle thereof. One end 24b of the gear support 24 is fixed to a shaft-like support 31 (see FIG. 2) standing up from the base 23 with a screw 32, and the other end 24c is fixed to a yoke connecting portion 48c described later with a screw 56. It is installed by. The gear support 24 does not protrude from the peripheral edge 23 a of the base 23 and is disposed inside the peripheral edge, in other words, in the projection region of the base 23.

  As shown in FIGS. 1 and 2, a plurality of guides 34, for example, two guides 34 are attached to the base 23 so as to be positioned on a straight line passing through the center of the base 23. A cover 25 is attached to these guides 34 by screwing or the like. The cover 25 has an outer diameter equal to or smaller than the diameter of the base 23 and covers the gear support 24 and the like. The cover 25 has a window hole 25a facing the entrance surface of the lens barrel 26 at the center thereof, and is thus formed in a donut shape as shown in FIG.

  The lens barrel 26 has a plurality of lenses 26a housed therein. The lens barrel 26 has a lens barrel holder 35 that is screwed onto the outer periphery thereof. A plurality of, for example, a pair of sliding portions 35a, preferably projecting substantially in the radial direction, are provided on the outer periphery of the lens barrel holder 35, and these sliding portions 35a are provided with shaft sliding elements such as through holes or concave grooves. Have. A guide 34 disposed around the lens barrel 26 is individually passed through the shaft sliding element. As a result, the lens barrel 26 is disposed at the center of the base 23 so as to face the image sensor 30 and is supported so as to be movable along the plurality of guides 34 in a direction in which it is in contact with and away from the image sensor 30. By this movement, the focusing operation of the lens barrel 26 with respect to the image sensor 30 is performed. 2 indicates the optical axis of the lens barrel 26.

  A coil spring 36 is wound around one guide 34. The coil spring 36 is sandwiched between one sliding portion 35a through which the one guide 34 penetrates and the base 23, and biases the lens barrel 26 in a direction away from the image sensor 30 via the lens barrel holder 35. doing.

  As shown in FIGS. 1 and 2, an outer protrusion 37 is provided on the outer periphery of the lens barrel holder 35 so as to approach the guide 34 on which the coil spring 36 is wound, for example. Further, as shown in FIGS. 1 and 3, a projection 38 for detecting a position is formed on the outer periphery of the lens barrel holder 35 so as to be spaced apart from the outward projecting portion 37 in the circumferential direction.

  The moving means 27 includes a feed screw 41 and a nut member 42. As shown in FIG. 2, the feed screw 41 forms a part of the gear shaft 43. The gear shaft 43 passes through the through-hole 24a of the gear support 24 and the outward projecting portion 37 facing the proximity thereof, and both ends of the gear shaft 43 are rotatably supported by the base 23 and the cover 25. ing. The nut member 42 is fixed to the outward projecting portion 37, and a feed screw 41 is meshed therethrough. Therefore, when the gear shaft 43 is rotated, the rotation is converted by the moving means 27 into a movement that moves the lens barrel holder 35 along the axial direction of the feed screw 41. Therefore, the lens barrel 26 is moved along the optical axis O.

  The stepping motor 28 is a two-pole motor having a step angle of 180 °, for example, and includes a coil block 45, a yoke 46, and a rotor 47 as shown in FIGS. The coil block 45 and the yoke 46 form a stator.

  The coil block 45 has an iron core 48 and an excitation coil 49. The iron core 48 is integrally provided with yoke connecting portions 48b or 48c at both ends in the longitudinal direction of the core portion 48a (see FIGS. 1 and 4), and the yoke connecting portion 48c is shared. A yoke connecting portion 48b is provided on each side via a core portion 48a. The exciting coils 49 are wound around the core portion 48a.

  One exciting coil 49 and one adjacent yoke connecting portion 48b are bent with respect to the yoke connecting portion 48c, and the other exciting coil 49 and the other adjacent yoke connection with respect to the yoke connecting portion 48c are bent. The part 48b is bent. As a result, the coil block 45 has a shape approximating a substantially circular arc, and is installed on the base 23 so as to be along the outer periphery of the lens barrel 26 as viewed in plan as shown in FIG. .

  The yoke 46 for guiding the magnetic flux generated by the excitation of the exciting coil 49 is flat and has end portions 46b and 46c connected to the yoke connecting portions 48b and 48c as shown in FIG. The pair of end portions 46b are individually connected to the yoke connecting portion 48b, and the other end portion 46c located between the pair of end portions 46b is connected to the yoke connecting portion 48c. The first to third magnetic path portions 46 </ b> X to 46 </ b> Z except for the end portions 46 b and 46 c of the yoke 46 protrude to the side of the coil block 45 without overlapping the coil block 45. A rotor through hole 50 is formed in a portion where the other ends of the first to third magnetic path portions 46X to 46Z are combined.

  The first magnetic path portion 46X and the second magnetic path portion 46Y have an arc shape. The third magnetic path portion 46Z positioned between the first and second magnetic path portions 46X and 46Y is formed in a ring shape. The third magnetic path portion 46Z is sized to be disposed along the outer periphery of the lens barrel 26 in a plan view as shown in FIG. 1 in a state where the stepping motor 28 is disposed on the base 23. Yes. The inner space S of the third magnetic path portion 46Z is large enough to accommodate a part used facing the lens barrel 26, for example, the image sensor 30.

  A gap G1 is formed between a part of the third magnetic path portion 46Z and the first magnetic path portion 46X facing the third magnetic path portion 46Z. The gap G1 is closed by the coil block 45. An exciting coil 49 on the side of the yoke coupling portion 48b to which the end portion 46b of the first magnetic path portion 46X is coupled faces the gap G1. A gap G2 is formed between the other portion of the third magnetic path portion 46Z and the second magnetic path portion 46Y facing the third magnetic path portion 46Z. The gap G2 is closed by the coil block 45. An exciting coil 49 on the side of the yoke coupling portion 48b to which the end portion 46b of the second magnetic path portion 46Y is coupled faces the gap G2.

  1 and 4, reference numeral 51 indicates a recess provided around the rotor through hole 50. Between the recess 51 and the rotor through hole 50, between the air gap G1 and the rotor through hole 50, and between the air gap G2 and the rotor through hole 50, the magnetic path cross-sectional area is extremely small, and it is extremely easy to magnetize. Saturates. For this reason, the inner peripheral surface of the rotor through-hole 50 is substantially divided at a portion where the magnetic path cross-sectional area is minimal. Each of the divided areas functions as a magnetic pole tip, and an S pole or an N pole appears at the magnetic pole tip every time a drive pulse is applied to the exciting coil 49.

  A rotor 47 is disposed in the rotor through hole 50. The outer peripheral portion of the rotor 47 is magnetized with different polarities for each predetermined region adjacent in the circumferential direction. Accordingly, the stepping motor 28 has a step angle of 180 ° by the magnetic action between the magnetic pole end and the magnetic pole of the rotor 47 every time a driving pulse is applied to the exciting coil 49 via a motor driver (not shown). It is rotated. As shown in FIGS. 1 and 2, the drive gear 53 is connected to or integrally formed with the rotor 47. Both ends of the rotation shaft 54 of the rotor 47 are rotatably supported by the base 23 and the gear support 24.

  The stepping motor 28 is fixed to one surface of the base 23 by first to third screws 55 to 57 (see FIG. 1) that connect the coil block 45 and the yoke 46. Specifically, the first screw 55 is screwed into the base 23 through one yoke coupling portion 48b of the iron core 48 and the end portion 46b of the first magnetic path portion 46X overlapped therewith, and one yoke coupling portion. The portion 48b and the first magnetic path portion 46X are connected. The second screw 56 is screwed into the base 23 through the other yoke coupling portion 48b of the iron core 48 and the end portion 46b of the second magnetic path portion 46Y overlapping with the other yoke coupling portion 48b. 2 magnetic path portions 46Y. The second screw 56 fastens the other end 24c of the gear support 24 together. The third screw 57 is screwed into the base 23 through the connecting portion 48c in the center of the iron core 48 and the end portion 46c of the third magnetic path portion 46Z overlapping therewith, and the connecting portion 48c and the third magnetic path. The portion 46Z is connected.

  By connecting the first magnetic path portion 46X and the second magnetic path portion 46Y and the coil block 45, these are continuous in a substantially circular annular structure that approximates the shape of the peripheral edge 23a of the base 23. The substantially circular size formed by the first magnetic path portion 46X and the second magnetic path portion 46Y and the coil block 45 is equal to or smaller than the diameter of the base 23 and larger than the diameter of the lens barrel 26. As shown in FIG. 1, the stepping motor 28 is screwed onto the base 23 to move the first magnetic path portion 46X, the second magnetic path portion 46Y, and the coil block 45 along the peripheral edge 23a of the base 23. Are arranged.

  Accordingly, the stepping motor 28 attached to the base 23 is concentrically disposed with respect to the lens barrel 26 while sharing the optical axis O of the lens barrel 26 without protruding from the peripheral edge 23 a of the base 23. In other words, the substantially circular annular structure formed by the coil block 45 and the first magnetic path portion 46X and the second magnetic path portion 46Y of the yoke 46 is formed on the outer periphery of the lens barrel 26 in plan view as shown in FIG. Are arranged along.

  The rotor 47 of the stepping motor 28 attached to the base 23 is disposed on the opposite side of the coil block 45 with the lens barrel 26 as a boundary. In addition, each of the coil block 45 and the yoke 46 is provided symmetrically with respect to a straight line (BB line) passing through the axis 47a (see FIG. 2) of the rotor 47 and the optical axis O. With this line-symmetric arrangement, the weight balance of the lens driving device 21 is improved, the lengths of the first and second magnetic path portions 46X and 46Y extending between the coil block 45 and the rotor through hole 50, and the third magnetic path portion. As the length of each part facing the gap G1 or G2 of 46Z becomes the same, the magnetic balance is improved.

  The guide 34 that guides the movement of the lens barrel 26 is disposed through the gap G1 or G2. For this reason, since the guide 34 and the sliding portion 35a of the lens barrel 26 engaged with the guide 34 are arranged inside the ring structure formed by the coil block 45 and the yoke 46, when the lens driving device 21 is viewed in a plane. In addition, the guide 34 and the sliding portion 35 a can be prevented from protruding outside the ring structure and the base 23. Furthermore, by arranging the guide 34 in the gap G1 or G2, the magnetic path cross-sectional areas of the magnetic path portions 46X and 46Y do not decrease compared to the configuration in which the guide 34 is passed through the magnetic path portions 46X and 46Y. For this reason, the arrangement of the guide 34 is preferable in that the motor performance of the stepping motor 28 is not adversely affected.

  The moving means 27 and the rotor 47 are connected via a reduction gear train 29 disposed on one surface side of the base 23. As shown in FIGS. 1 and 2, the reduction gear train 29 has a plurality of, for example, first to third reduction gears 61 to 63 made of spur gears. The first reduction gear 61 is engaged with the drive gear 53 of the rotor 47, and the second reduction gear 62 rotated together with the first reduction gear 61 is engaged with the third reduction gear 63. The third reduction gear 63 is attached to the gear shaft 43. Both ends of the gear shaft 64 that supports the first reduction gear 61 and the second reduction gear 62 are rotatably supported by the base 23 and the cover 25. Therefore, when the stepping motor 28 is driven and the rotor 47 is rotated, the rotation is decelerated by the reduction gear train 29 and given to the moving means 27.

  The gear shaft 43 and the gear shaft 64 are both disposed through the gap G2 using one gap G2. Accordingly, at least a part, preferably the whole, of the reduction gear 63 fixed to the gear shaft 43 can be placed on the stepping motor 28 and at least a part of the reduction gears 61 and 62 fixed to the gear shaft 64. Preferably, the entirety can be placed over the stepping motor 28. Accordingly, the reduction gear train 29 can be prevented from protruding outside the ring structure and the base 23.

  Reference numeral 67 in FIGS. 1 and 3 denotes a non-contact type sensor that detects the amount of movement of the lens barrel 26 along the optical axis O. The sensor 67 has, for example, a concave groove 67a, and a protrusion 38 of the lens barrel 26 is inserted into the concave groove 67a. The sensor 67 detects the amount of movement of the lens barrel 26 by the protrusion 38 moving in the groove 67a in the direction in which the groove 67a extends. Information detected by the sensor 67 is used as control information for the stepping motor 28. The sensor 67 is located on the inner periphery of the base 23 so as not to protrude outside the base 23 in plan view, specifically on the outer periphery of the coil block 45 and the magnetic path portions 46X and 46Y of the yoke 46 arranged in an annular shape. Arranged inside.

  As shown in FIG. 1, the lens driving device 21 having the above-described configuration includes a stepping motor 28, a lens barrel 26 having a circular outer periphery, a lens barrel 26 inside a peripheral edge 23 a of a base 23 having a circular shape. Are arranged along the optical axis direction, and a reduction gear train 29 for linking the moving means 27 and the rotor 47 of the stepping motor 28 is disposed.

  For this reason, the lens driving device 21 which is an optical module can be made substantially circular in plan view. In addition, it is possible to suppress each component from interfering with components arranged around the lens driving device 21.

  Thereby, a high degree of freedom in arrangement of the lens driving device 21 with respect to a device on which the lens driving device 21 is mounted can be obtained. Therefore, for example, the positional relationship between the connector connected to the exciting coil 49 and the sensor 67 via the lead wire and the connector on the device side connected thereto, and the lead wire is not caught by the surrounding parts. In consideration of this, the lens driving device 21 can be rotated around the optical axis O of the lens barrel 26 to correspond to the direction of the lens driving device 21. In addition, when the equipment on which the lens driving device 21 is mounted is made compact, the degree of freedom in arrangement does not become a factor for suppressing the compactness.

  Further, in the above arrangement, the coil block 45 and the yoke 46 which are connected to each other and form an annular shape of the stepping motor 28 are arranged along the outer periphery of the lens barrel 26 arranged in the center of the base 23 in plan view. At the same time, the rotor 47, the moving means 27, the reduction gear train 29, and the sensor 67 are removed from between the coil block 45 and the lens barrel 26 and arranged along the outer periphery of the lens barrel 26 in plan view. . As a result, the stepping motor 28 can be arranged concentrically so as to share the optical axis O with respect to the lens barrel 26 when viewed in a plan view, which is suitable for making the lens driving device 21 small in diameter. It is possible to reduce the arrangement space of the drive device 21.

  Moreover, in the above arrangement, the rotor 47, the moving means 27, the reduction gear train 29, and the sensor 67 are arranged on the opposite side of the coil block 45 with the lens barrel 26 as a boundary. Accordingly, the guide 34 for guiding the movement of the lens barrel 26 does not interfere with the rotor 47, the moving means 27, the reduction gear train 29, the sensor 67, and the coil block 45, and the rotor 47, the moving means 27, the reduction gear train. 29 and the group of sensors 67 and the coil block 45 can be provided.

  The stepping motor 28 moves the exciting coil 49 that generates magnetic flux when a driving pulse is applied and the rotor through-hole 50 in which the rotor 47 is disposed along one surface of the base 23, and generates the generated magnetic flux. The rotor 47 is rotated by being guided to the rotor through hole 50 by the magnetic path portions 46 </ b> X to 46 </ b> Z of the yoke 46. For this reason, the positional relationship between the exciting coil 49 and the rotor 47 is not particularly limited, and even if the coil block 45 is arbitrarily arranged with respect to the rotor 47, it can function as a motor. Therefore, the rotor through-hole 50 and the rotor 47 can be disposed at any position of the yoke 46 that is disposed concentrically with the lens barrel 26 in plan view. Thereby, it is possible to freely design the arrangement of the rotor 47, the reduction gear train 29 linked to the rotor 47, and the moving means 27 in accordance with the arrangement state of the surrounding parts.

  Furthermore, since the coil block 45 is disposed along the outer periphery of the lens barrel 26 as viewed in a plan view, there is no significant restriction on the length thereof. For this reason, even if the performance of the stepping motor 28 is changed by freely changing the number of turns of the exciting coil 49 of the coil block 45, it does not become a factor for increasing the diameter of the lens driving device 21. Therefore, the degree of freedom in changing the performance of the stepping motor 28 is high.

  The stepping motor 28 used in the lens driving device 21 having the above-described configuration is not a cylindrical type, but a coil block 45 having an excitation coil 49 disposed along one surface of the base 23 and an end connected to the block 45. Magnetic path portions 46 </ b> X to 46 </ b> Z other than 46 b and 46 c include a yoke 46 provided along the base 23 without overlapping the coil block 45, and a rotor 47 disposed in the rotor through hole 50 of the yoke 46. Therefore, it can be configured in a flat shape. For this reason, the stepping motor 28 is not an element that increases the thickness of the lens driving device 21. In addition, since the peripheral surface of the exciting coil 49 of the stepping motor 28 is provided horizontally along the base 23, the winding length of the exciting coil 49 around the core portion 48a is increased in order to increase the magnetic flux. Even if it exists, it does not become an element which increases the thickness of the stepping motor 28 and, consequently, the thickness of the lens driving device 21.

  Therefore, although the optical axis O of the lens barrel 26 and the axis 47a of the rotor 47 are parallel to each other, the entire lens driving device 21 is compared with a lens driving device using a cylindrical stepping motor. The thickness can be reduced.

  The lens driving device 21 configured as described above uses the reduction gear train 29 formed of a spur gear as described above to transmit the rotation of the rotor 47 to the moving means 27 that moves the lens barrel 26. Since the reduction gear train 29 does not obtain a large reduction ratio in one stage unlike a worm gear, the power loss due to sliding friction is small, and accordingly the power consumption of the stepping motor 28 can be reduced. In addition, although the step angle is 180 °, the feed screw 51 of the moving means 27 is decelerated and rotated in accordance with the reduction ratio of the reduction gear train 29, so that the lens barrel 26 is moved through the nut member 52, for example. It can be moved with high accuracy on the order of 10 microns to perform a focusing operation.

  7 to 10 show a second embodiment of the present invention. Since this embodiment is basically the same as the first embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. Hereinafter, the differences from the first embodiment are described. explain.

  In the second embodiment, as shown in FIG. 9, through holes 71 are provided in the magnetic path portions 46X and 46Y of the yoke 46, respectively. As shown in FIGS. 7 and 8, one guide 34 is passed through the through hole 71 of the magnetic path portion 46X, and the other guide 34 and the coil spring 36 wound around the guide 34 are passed through the through hole 71 of the magnetic path portion 46Y. Is passed. Even in such a configuration, the guide 34 can be disposed inside the outer periphery of the magnetic path portions 46X and 46Y of the coil block 45 and the yoke 46 arranged in an annular shape, and the maximum diameter is defined by the peripheral edge 23a of the circular base 23. When the lens driving device 21 as an optical module is viewed in plan, the guide 34 and the sliding portion 35a engaged therewith can be prevented from protruding outside the base 23. A part of the gear support 24 shown in FIG. 10 is provided between one sliding portion 35 a engaged with the other guide 34 and the yoke 46. The configuration other than the points described above is the same as that of the first embodiment.

  Therefore, this second embodiment can solve the problems of the present invention by obtaining the same action as the first embodiment.

  The present invention is not limited to the above embodiments. For example, instead of passing the gear shafts 43 and 64 of the reduction gear train 29 through the gap G2 (may be the gap G1), a through hole is provided in the magnetic path portion 46Y (may be the magnetic path portion 46X) of the yoke 46. The gear shafts 43 and 64 can also be rotatably supported by the base 23 and the gear support 24 through the gear shafts 43 and 64 of the reduction gear train 29 through the through holes.

  In the present invention, the optical component may be moved other than the focusing operation, for example, for a zooming operation. Further, instead of the feed screw and the nut member, the moving means may be configured such that the cylindrical cam is moved by the rotation of the gear shaft 43 and the optical parts such as the lens barrel are moved by this cam.

The top view which shows the lens drive device which concerns on 1st Embodiment of this invention in the state which removed the cover and the gear support. Sectional drawing of the lens drive device shown along F2-F2 line | wire in FIG. Sectional drawing of the lens drive device shown along F3-F3 line in FIG. The top view shown in the state which isolate | separated the yoke and coil block of the stepping motor with which the lens drive device of FIG. 1 is provided. The top view which shows the cover with which the lens drive device of FIG. 1 is provided. The top view which shows the gear support with which the lens drive device of FIG. 1 is provided. The top view which shows the lens drive device which concerns on 2nd Embodiment of this invention in the state which removed the cover and the gear support. Sectional drawing of the lens drive device shown along F8-F8 line | wire in FIG. The top view which shows the yoke of the stepping motor with which the lens drive device of FIG. 7 is provided. The top view which shows the gear support with which the lens drive device of FIG. 7 is provided. The top view which shows the lens drive device which concerns on a prior art example in the state which removed the cover. Sectional drawing which shows the lens drive device which concerns on a prior art example.

Explanation of symbols

21 ... Lens driving device (optical module)
DESCRIPTION OF SYMBOLS 22 ... Circuit board 23 ... Base 23a ... Periphery of base 24 ... Gear support 25 ... Cover 26 ... Lens barrel (optical component)
DESCRIPTION OF SYMBOLS 27 ... Moving means 28 ... Stepping motor 29 ... Reduction gear train 30 ... Image pick-up element 34 ... Guide 35 ... Lens barrel holder 35a ... Slide portion of lens barrel holder 37 ... Outward projecting portion of lens barrel holder O ... Mirror Optical axis of cylinder (optical axis of optical component)
41 ... Feed screw of moving means 42 ... Nut member of moving means 43 ... Gear shaft 45 ... Coil block 46 ... Yoke 46b, 46c ... End of yoke 46X ... First magnetic path portion of yoke 46Y ... Second of yoke Magnetic path portion 46Z ... Third magnetic path portion of yoke S ... Inner space of third magnetic path portion 47 ... Rotor 47a ... Rotor axis 48 ... Iron core 48a ... Core portion of core 48b, 48c ... Yoke connecting portion of iron core DESCRIPTION OF SYMBOLS 49 ... Excitation coil 50 ... Rotor through-hole G1, G2 ... Air gap 53 ... Drive gear 54 ... Rotating shaft 61 ... 1st reduction gear 62 ... 2nd reduction gear 63 ... 3rd reduction gear 64 ... Gear shaft 67 ... Sensor 71 ... Through hole in magnetic path

Claims (13)

  A stepping motor, an optical component having an optical axis extending in the axial direction, and a circular outer periphery formed inside the peripheral edge of the base that forms a circular shape when seen in a plan view, and the optical component along the optical axis An optical module in which moving means for moving the moving means and a reduction gear train for interlocking the moving means and the rotor of the stepping motor are arranged. Stepping comprising a coil block having an exciting coil, a yoke provided with a magnetic path portion other than the end connected to the block without overlapping the coil block, and a rotor disposed in a rotor through hole of the yoke A motor,
An optical component having an optical axis extending in the axial direction and having a circular outer periphery;
Moving means for moving the optical component along the optical axis;
A reduction gear train for interlocking the moving means and the rotor;
It has a circular shape in plan view, and includes a base on which the stepping motor, the optical component, the moving means, and the reduction gear train are arranged on the inner side of the periphery thereof,
The optical component is arranged at the center of the base, the stepping motor is arranged concentrically with the optical component by sharing the optical axis of the optical component, and the moving means and the reduction gear train are planar. And an optical module disposed along the outer periphery of the optical component. Stepping comprising a coil block having an exciting coil, a yoke provided with a magnetic path portion other than the end connected to the block without overlapping the coil block, and a rotor disposed in a rotor through hole of the yoke A motor,
An optical component having an optical axis extending in the axial direction and having a circular outer periphery;
Moving means for moving the optical component along the optical axis;
A reduction gear train for interlocking the moving means and the rotor;
It has a circular shape in plan view, and includes a base on which the stepping motor, the optical component, the moving means, and the reduction gear train are arranged on the inner side of the periphery thereof,
The optical component is disposed at the center of the base, and the coil block and the yoke connected to each other in an annular shape are disposed along the outer periphery of the optical component in plan view, and the rotor and moving means And an optical module in which a reduction gear train is removed from between the coil block and the optical component and arranged along the outer periphery of the optical component in plan view.   The optical module according to claim 2, wherein the coil block is bent along the outer periphery of the optical component when viewed in plan.   5. The optical module according to claim 2, wherein the rotor, the moving unit, and the reduction gear train are arranged on the opposite side of the coil block with the optical component as a boundary.   6. The optical component, the moving means, and the reduction gear train are disposed in an inner periphery of the outer periphery of the coil block and the yoke that are connected to each other in an annular shape. An optical module according to 1.   7. The optical device according to claim 2, wherein the coil block and the yoke that are connected to each other in an annular shape are provided symmetrically with respect to a straight line that passes through the axis of the rotor and the optical axis. module.   The exciting coil is provided between the first and second yoke connecting portions located at both ends of the coil block and the third yoke connecting portion located at the center, respectively, and the yoke includes the first and second yoke connecting portions. The first and second magnetic path portions having one end individually connected to the second yoke connecting portion and the other end facing the rotor through hole, and located between the first and second magnetic path portions A ring-shaped third magnetic path portion having one end connected to the third yoke connecting portion and the other end facing the rotor through hole, and the third magnetic path portion and the first magnet The optical module according to any one of claims 2 to 7, wherein a gap is provided between a path portion and the second magnetic path portion.   The optical module according to claim 8, wherein a guide for guiding the movement of the optical component is disposed through the gap.   9. The optical module according to claim 2, wherein a through hole is provided in a magnetic path portion of the yoke, and a guide for guiding the movement of the optical component is passed through the through hole.   The optical module according to claim 8, wherein a gear shaft included in the reduction gear train is disposed so as to penetrate the gap.   9. The optical module according to claim 2, wherein a through hole is provided in a magnetic path portion of the yoke, and a gear shaft included in the reduction gear train is passed through the through hole.   A sensor for detecting the amount of movement of the optical component along the optical axis is provided, and the sensor is arranged inside the outer periphery of the coil block and the yoke that are connected to each other in an annular shape. The optical module according to claim 1.

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