JP2005234210A - Lens moving mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens moving mechanism capable of eliminating backlash between the 1st screw part of a supporting body and the 2nd screw part of a lens holding body screwed with the 1st screw part. <P>SOLUTION: The lens moving mechanism is equipped with a lower guide 7 supporting a rotor member including a cylindrical magnet 4 and a rotor yoke 5, arranged inside the rotor yoke 5 and having the 1st screw part 7b, and a holder 10 arranged inside the guide 7 and having the 2nd screw part 10a screwed with the 1st screw part 7b, and the yoke 5 has a guide pin 16 rotating the holder 10. Then, it is equipped with a spring member 18 energizing the guide pin 16 and the holder 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lens moving mechanism that moves a lens holder that holds a lens in the optical axis direction while rotating by driving a motor.

  There exists a thing shown by patent document 1 as this type of prior art. In this prior art, a rotor member that can be rotated by driving a motor, a support member that supports the motor including the rotor member, and that has a first threaded portion on the inner periphery, and a lens disposed on the inner side of the support member. And a lens holder having a second screw portion that is held and is engaged with the first screw portion of the support body on the outer periphery. The rotor member described above has an engaging portion that rotates the lens holder. This engaging part consists of the protrusion piece contact | abutted to the groove part formed in the outer peripheral part of a lens holding body.

In this prior art, when the rotor member is rotated by driving the motor, the lens holding body rotates through the engaging portion of the rotor member. As the lens holder rotates, the lens holder moves to a predetermined focal position in the optical axis direction through screwing of the first screw portion of the support and the second screw portion of the lens holder. It has become.
JP 2002-51524 A

  The above-described conventional technology moves the lens holder in the optical axis direction through screwing between the first screw portion of the support and the second screw portion of the lens holder. Due to the gap formed between the second screw portion and the lens holder, the backlash tends to occur when the lens holder is moved in the optical axis direction. For this reason, there is a problem that it is difficult to expect improvement in the accuracy of movement and positioning of the lens holder in the optical axis direction.

  In the prior art, the rotor member is apt to be loose while the rotor member is rotating due to the gap around the rotor member that is unavoidable due to the structure. For this reason, there exists a possibility that the transmission accuracy of the rotational force of a rotor member to the lens holding body may fall. Thereby, from a viewpoint different from the above, there is a possibility that the movement positioning accuracy of the lens holder in the optical axis direction is lowered.

  The present invention is made from the actual state in the above-described prior art, and an object thereof is between the first threaded portion of the support and the second threaded portion of the lens holder that is screwed with the first threaded portion. It is an object of the present invention to provide a lens moving mechanism that can eliminate backlash.

  In order to achieve the above object, the present invention provides a rotor member that rotates by driving a motor, a support member that rotatably supports the rotor member, and a first screw portion on the inner periphery, and an inner side of the support member. A lens holder that holds the lens and has a second threaded portion that engages with the first threaded portion of the support on the outer periphery, and the rotor member rotates the lens retaining body. A rotating member that rotates the rotor member to rotate the lens holder through the engaging portion, and moves the lens holder in the direction of the optical axis. A spring member is provided inside the member and biases the lens holding body.

  The present invention configured as described above can apply the biasing force of the spring member to the lens holder. Thereby, the 2nd screw part of a lens holding body is pressed by the 1st screw part of a support body, and it can be made not to produce a crevice in the contact portion of these 1st screw parts and the 2nd screw part. In such a state, when the rotor member is rotated in accordance with the driving of the motor, the lens holding body is rotated through the engaging portion of the rotor member, and the second screw portion of the lens holding body and the first of the support body are rotated. The lens holder moves in the direction of the optical axis to a predetermined focal position via one screw part. During the movement of the lens holder in the optical axis direction, as described above, there is no gap between the first screw portion and the second screw portion, and therefore the lens holder can be moved without causing play. it can.

  According to the present invention, in the above invention, the support has an opening, the spring member is disposed between the engagement portion of the rotor member and the lens holding body, and the engagement portion is It has a roller member that is pressed against the edge of the support that forms the opening, and that is pushed and moved in the rotation direction on the edge as the rotor member rotates.

  In the present invention configured as described above, in particular, the roller member included in the engaging portion of the rotor member is constantly pressed against the edge of the opening of the support member by the biasing force of the spring member, and accordingly, when the rotor member rotates. The backlash does not occur in this rotor member. Thereby, the rotational force of the rotor member can be transmitted to the lens holder with high accuracy.

  Further, the present invention is the above invention, wherein the lens holding body includes a lens barrel that holds the lens and a holder to which the lens barrel is attached. The outer peripheral surface of the lens barrel and the inner peripheral surface of the holder Further, the present invention is characterized in that a mounting screw portion that enables the lens barrel to be removed is provided. In the present invention configured as described above, since the lens barrel can be detached from the holder, the lens barrel can be easily replaced.

  According to the present invention, in the above invention, a vent hole is formed in the wall portion of the support so as to allow air to flow as the lens holder moves in the optical axis direction. In the present invention configured as described above, since the air is moved relative to the support body through the vent hole, the lens holding body can be moved smoothly.

  Further, the present invention is the above invention, wherein the lens holder comprises a lens barrel for holding the lens, and a holder to which the lens barrel is attached and having the second screw portion, and the support is A lower guide that has a first screw portion and is held immovably; and a rotor cap that is disposed to face the lower guide and has the engagement portion and also serves as a part of the rotor member. The spring member is arranged between the rotor cap and the rotor cap.

  In the present invention configured as described above, the second screw portion of the holder of the lens holder is pressed against the first screw portion of the lower guide of the support member by the biasing force of the spring member, and the first screw portion and the second screw It is possible to prevent a gap from occurring at the contact portion with the portion. In such a state, when the rotor member is rotated as the motor is driven, the lens holding body is rotated through the engaging portion of the rotor cap, and the second screw portion of the holder of the lens holding body and the first of the lower guide are rotated. The lens holder can be moved in the direction of the optical axis through one screw portion without causing play. Further, when the rotor cap is pressed by the spring member, the rotor member including the rotor cap does not play. Thereby, the rotational force of the rotor member can be transmitted to the lens holder with high accuracy.

  In the present invention, since the spring member is provided between the engaging portion of the support body and the lens holding body, a gap is generated at the contact portion between the first screw portion of the support body and the second screw portion of the lens holding body. You can avoid it. As a result, when the lens holder is moved in the optical axis direction, the lens holder can be moved without causing play between the first screw portion and the second screw portion. The accuracy can be improved as compared with the prior art.

  Further, according to the present invention, since the engaging portion of the rotor member has the roller member pressed against the edge of the opening formed in the support, the roller member is always pressed against the edge of the support when the rotor member rotates. The rotor member will not be loose. Thereby, the rotational force of the rotor member can be transmitted to the lens holding body with high accuracy, and the movement positioning accuracy of the lens holding body can be further improved.

  According to the present invention, the lens holder includes a lens barrel that holds the lens and a holder to which the lens barrel is attached and has a second screw portion, and the support has a first screw portion and moves. A lower guide that is held in an impossible manner, and a rotor cap that is disposed opposite the lower guide and has an engaging portion and also serves as a part of the rotor member, and the spring member is disposed between the holder and the rotor cap. It is arranged. Since it comprised in this way, the 2nd thread part of a lens holding body is pressed by the 1st thread part of the lower guide which comprises a support body by the urging | biasing force of a spring member, These 1st thread part, 2nd thread part, It is possible to prevent a gap from occurring in the contact portion. Thereby, when the lens holder is moved in the optical axis direction, the lens holder can be moved without causing play between the first screw portion and the second screw portion. Further, since the rotor cap is pressed by the spring member, the rotor member including the rotor cap does not play when rotating. Therefore, the rotational force of the rotor member can be transmitted to the lens holder with high accuracy. Accordingly, it is possible to ensure excellent movement positioning accuracy of the lens holder.

  Hereinafter, the best mode for carrying out a lens moving mechanism according to the present invention will be described with reference to the drawings.

    FIG. 1 is a longitudinal sectional view showing a first embodiment of a lens moving mechanism according to the present invention, and FIG. 2 is a perspective view showing an appearance of the first embodiment shown in FIG.

  FIG. 3 is a longitudinal sectional view showing a state in which the lens cap, the lens barrel, and the lens are removed from the first embodiment shown in FIG. 4 is a perspective view showing a state in which the stopper plate and the lens cap are removed from the first embodiment shown in FIG. 2, and FIG. 5 is a view showing the stopper plate, the lens cap, the lens barrel, and the lens from the first embodiment shown in FIG. It is a perspective view which shows the state removed. 6 is a perspective view showing the assembly relationship of the lower guide, rotor yoke, guide pin, roller member, holder, and spring member provided in the first embodiment shown in FIGS. 1 and 2, and FIG. 7 is a first view shown in FIGS. It is a perspective view which shows the assembly | attachment relationship of the rotor yoke with which 1 embodiment is equipped, a guide pin, and a roller member. FIG. 8 is an enlarged view of a main part of FIG.

  As shown in these drawings, particularly FIGS. 1 and 2, the first embodiment includes a base 1, an outer yoke 2 fixed to the base 1, a claw pole magnetic pole 3 housed in the outer yoke 2, A cylindrical magnet 4 disposed inside the claw pole magnetic pole 3 and a rotor yoke 5 disposed inside the cylindrical magnet 4 and provided integrally with the cylindrical magnet 4 are provided. The outer yoke 2, the claw pole magnetic pole 3, the cylindrical magnet 4 and the rotor yoke 5 described above constitute a motor, for example, a micro motor. Further, the cylindrical magnet 4 and the rotor yoke 5 described above constitute a rotor member that rotates by driving of a motor. That is, in the first embodiment, a rotor member is included in the motor.

  Further, a support body for supporting the rotor member is arranged inside the rotor yoke 5 constituting the rotor member. The support body is formed on the base 1 so as to be immovable, an upper guide 8 disposed so as to face the lower guide 7, and the lower guide 7 and the upper guide 8. Includes an annular opening 9.

  As shown also in FIG. 8, the lower guide 7 constituting the support body has a vent hole 7 a through which air is circulated in the wall portion and a first screw portion 7 b on the inner periphery.

  A lens holder is disposed inside the lower guide 7. As shown in FIG. 1, the lens holder is attached to the holder 10 having a second screw portion 10 a screwed to the first screw portion 7 b of the lower guide 7 on the outer periphery, and holds the lens 12. The lens barrel 11 is made up of. As shown in FIG. 8, the mounting screw portion 11 a provided on the outer peripheral surface of the lens barrel 11 and the mounting screw portion 10 b provided on the inner peripheral surface of the holder 10 are screwed together. As a result, the lens barrel 11 can be removed from the holder 10. In addition, as shown in FIG. 6, the holder 10 is formed with groove portions 10c at equal intervals, for example, at three locations in the circumferential direction.

  A lens cap 13 is attached to the lens barrel 11 as shown in FIG. A stopper plate 14 that restricts the movement of the lens holder including the holder 10 and the lens barrel 11 in the optical axis direction is disposed so as to face the lens cap 13.

  Note that an imaging element, that is, an image sensor 15 is mounted on the base 1 so as to face the lens holder described above.

  In the first embodiment, the rotor member described above includes an engaging portion that rotates the lens holder described above. As shown in FIGS. 1, 6, 7, 8, etc., this engaging portion is engaged with, for example, a rotor yoke 5 that constitutes a rotor member, and is provided with three guides arranged at equal intervals in the circumferential direction of the rotor yoke 5. The pin 16 and the roller member 17 rotatably mounted on each of the guide pins 16 are included. As shown in FIG. 8, the roller member 17 is pressed against the end edge 8 a of the upper guide 8 that forms the opening 9, and the rotor member, that is, the rotor yoke 5 rotates on the end edge 8 a of the upper guide 8 as the rotor yoke 5 rotates. 5 is pushed in the direction of rotation.

  Each of the three guide pins 16 described above is individually housed in each of the three groove portions 10c formed in the holder 10, and transmits the rotational force of the rotor yoke 5 to the holder 10 via the wall surface of the groove portion 10c.

  In the first embodiment, as shown in FIGS. 1 and 8 and the like, the engaging portion and the lens holding body are urged between the engaging portion of the supporting body and the lens holding body. The spring member 18 is provided. In other words, each of the guide pins 16 constituting the engaging portion is provided with a spring member 18 having one end engaged with the holder 10 constituting the lens holding body.

  In the first embodiment configured as described above, the cylindrical magnet 4 and the rotor yoke 5 which are rotor members are rotated by driving the motor including the claw pole magnetic pole 3. As the rotor yoke 5 rotates, each roller member 17 mounted on the guide pin 16 is pressed against the edge 8a of the upper guide 8 that forms the opening 9 by the biasing force of the spring member 18, and the rotor yoke 5 rotates. Each of the guide pins 16 presses the wall surface of the groove 10c of the holder 10 while being pushed and moved in the direction. Therefore, the rotation of the rotor yoke 5 is transmitted to the holder 10 through the guide pins 16, and the holder 10, the lens barrel 11 that holds the lens 12, and the lens holder including the lens cap 13 rotate integrally.

  As the holder 10 rotates, the holder 10 moves in the optical axis direction indicated by the arrow 19 in FIG. 1 through the screwing of the second screw portion 10 a of the holder 10 and the first screw portion 10 b of the lower guide 7. That is, the lens barrel 11 and the lens cap 13 that hold the lens 12 integrally with the holder 10 move in the direction of the arrow 19. In this way, the lens 12 moves to a predetermined focal position in the optical axis direction within a moving range of, for example, 200 mμ to 300 mμ. An image of the subject obtained through the lens 12 at this focal position is taken into the image sensor 15, and a corresponding image signal is output from the image sensor 15.

  According to the first embodiment configured as described above, the urging force of the spring member 18 can be applied to both the holder 10 constituting the lens holder and the guide pin 16 constituting the engaging portion.

  Due to the biasing force of the spring member 18 applied to the holder 10, the second screw portion 10a of the holder 10 is pressed against the first screw portion 7b of the lower guide 7 constituting the support, and as shown in FIG. It is possible to prevent a gap from occurring at the contact portion between the screw portion 7b and the second screw portion 10b. Accordingly, when the holder 10 constituting the lens holding body is rotated as described above to move the lens 12 held by the lens barrel 11 in the optical axis direction, it is between the first screw portion 7b and the second screw portion 10b. The lens holder including the holder 10 and the lens barrel 11 that holds the lens 12 can be moved without causing backlash. Thereby, the outstanding movement positioning accuracy of a lens holding body is securable.

  Further, the roller member 17 attached to the guide pin 16 rotates in the rotational direction of the rotor yoke 5 without always separating from the edge 8 a of the upper guide 8 by the biasing force of the spring member 18 applied to the guide pin 16. Therefore, when the rotor member including the rotor yoke 5 and the cylindrical magnet 4 is rotated, the rotor member is not rattled. Thus, the rotational force of the rotor member, that is, the rotational force applied to the rotor yoke 5 can be transmitted to the holder 10 constituting the lens holder with high accuracy via the guide pin 16 and the roller member 17. The moving positioning accuracy can be further improved.

  In the first embodiment, the mounting screw portion 11a of the lens barrel 11 constituting the lens holder and the mounting screw portion 10b of the holder 10 are screwed together, and the lens barrel 11 is the holder. Since the lens barrel 11 can be removed, the lens barrel 11 can be easily replaced. Therefore, the functionality can be improved by preparing a plurality of lens barrels 11 for holding different types of lenses 12.

  Further, in the first embodiment, since the vent hole 7a is formed in the wall portion of the lower guide 7 constituting the support body, the lower guide 7 is moved when the lens holder including the holder 10 and the lens barrel 11 is moved. The movement of air to the inside can be performed through the vent hole 7a. As a result, the above-described lens holder can be smoothly moved, and a highly reliable lens moving mechanism can be obtained.

  FIG. 9 is a longitudinal sectional view showing a second embodiment of the present invention, and FIG. 10 is a longitudinal sectional view showing an assembly relation of a rotor yoke, a cylindrical magnet, and a rotor cap provided in the second embodiment shown in FIG.

  In the second embodiment, a rotor cap 20 constituting a support disposed so as to face the lower guide 7 is rotatably provided, and is configured to serve also as a part of the rotor member. That is, as shown in FIG. 10, the cylindrical magnet 4, the rotor yoke 5, and the rotor cap 20 are formed into an integral structure by bonding, for example.

  In addition, as an engaging portion for rotating the holder 10 constituting the lens holder, the three groove portions 3c of the holder 10 are provided in the rotor cap 20 instead of the guide pin 16 and the roller member 17 in the first embodiment described above. In order to engage with each of the wall surfaces, engaging portions 20a formed at equal intervals and thick at three locations in the circumferential direction are provided. A holding plate 21 that rotatably holds the rotor cap 20 is disposed between the rotor cap 20 and the rotor yoke 2. Each of the rotor cap 20 and the holding plate 21 is formed with circular holes 20b and 21a facing the lens barrel 11 holding the lens 12, respectively. The spring member 18 is disposed between the holder 10 and the rotor cap 20. As a result, the rotor cap 20 is held in contact with the holding plate 21. Other configurations are the same as those of the first embodiment described above, for example.

  In the second embodiment configured as described above, the second screw portion 10a of the holder 10 constituting the lens holding body is pressed by the first screw portion 7b of the lower guide 7 constituting the support by the biasing force of the spring member 18, It is possible to prevent a gap from occurring at the contact portion between the first screw portion 7b and the second screw portion 10a. Accordingly, when the rotor member, that is, the integrated structure composed of the cylindrical magnet 4, the rotor yoke 5, and the rotor cap 20 rotates as the motor is driven, the holder constituting the lens holding body via the engaging portion 20 a of the rotor cap 20. 10 rotates. Thus, the lens holder including the holder 10 and the lens barrel 11 that holds the lens 12 is moved in the optical axis direction through the first screw portion 7b and the second screw portion 10b without causing backlash. Therefore, it is possible to secure excellent movement positioning accuracy of the lens holder.

  Further, the rotor cap 20 is pressed against the holding plate 21 by the spring member 18. Therefore, the rotor member including the rotor cap 20, the cylindrical magnet 4, and the rotor yoke 5 does not play when rotating. Thereby, the rotational force of the rotor member can be transmitted to the lens holder with high accuracy, and this also ensures excellent movement positioning accuracy of the lens holder.

It is a longitudinal cross-sectional view which shows 1st Embodiment of the lens moving mechanism which concerns on this invention. It is a perspective view which shows the external appearance of 1st Embodiment shown in FIG. It is a longitudinal cross-sectional view which shows the state which removed the lens cap, the lens barrel, and the lens from 1st Embodiment shown in FIG. It is a perspective view which shows the state which removed the stopper plate and the lens cap from 1st Embodiment shown in FIG. It is a perspective view which shows the state which removed the stopper plate, the lens cap, the lens-barrel, and the lens from 1st Embodiment shown in FIG. It is a perspective view which shows the assembly | attachment relationship of the lower guide with which 1st Embodiment shown in FIG.1, 2 is equipped, a rotor pin, a guide pin, a roller member, a holder, and a spring member. It is a perspective view which shows the assembly | attachment relationship of the rotor yoke, guide pin, and roller member with which 1st Embodiment shown in FIG. It is a principal part enlarged view of FIG. It is a longitudinal cross-sectional view which shows 2nd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the assembly | attachment relationship of the rotor yoke, cylindrical magnet, and rotor cap with which 2nd Embodiment shown in FIG. 9 is equipped.

Explanation of symbols

1 base 2 outer yoke 3 claw pole magnetic pole 4 cylindrical magnet (rotor member)
5 Rotor yoke (rotor member)
7 Lower guide (support)
7a Ventilation hole 7b First screw part 8 Upper guide (support)
8a Edge 9 Opening 10 Holder (Lens holder)
10a Second screw portion 10b Mounting screw portion 10c Groove portion 11 Lens barrel (lens holder)
11a Attaching screw part 12 Lens 13 Lens cap (lens holder)
14 Stopper plate 15 Image sensor 16 Guide pin (engagement part)
17 Roller member (engagement part)
18 Spring member 19 Arrow 20 Rotor cap (support) (rotor member)
20a Engagement part 20b Circular hole 21 Holding plate 21a Circular hole

Claims (5)

A rotor member that rotates by driving of the motor, a support member that rotatably supports the rotor member, and a first screw portion on the inner periphery, and a lens that is disposed on the inner side of the support member and holds the lens on the outer periphery. A lens holder having a second threaded portion that is screwed with the first threaded portion of the support, and the rotor member has an engaging portion that rotates the lens retaining body, and rotates the rotor member. Accordingly, the lens holder is rotated via the engaging portion, and the lens holder is moved in the optical axis direction.
The support is disposed inside the rotor member;
A lens moving mechanism comprising a spring member for biasing the lens holder. In the invention of claim 1,
The support has an opening,
The spring member is disposed between the engagement portion of the rotor member and the lens holder,
The engaging portion includes a roller member that is pressed against an edge of the support that forms the opening, and that is pushed and moved in the rotational direction on the edge as the rotor member rotates. Lens moving mechanism. In the invention according to claim 1 or 2,
The lens holder includes a lens barrel that holds the lens, and a holder to which the lens barrel is attached.
A lens moving mechanism, characterized in that a mounting screw portion is provided on the outer peripheral surface of the lens barrel and the inner peripheral surface of the holder so that the lens barrel can be removed. In the invention of claim 1,
A lens moving mechanism characterized in that a vent hole is formed in the wall portion of the support so as to allow air to flow along with the movement of the lens holder in the optical axis direction. In the invention of claim 1,
The lens holder includes a lens barrel that holds the lens, and a holder to which the lens barrel is attached and has the second screw portion.
A lower guide that has the first screw portion and is held immovably; and a rotor cap that is disposed to face the lower guide and has the engagement portion and also serves as a part of the rotor member. Including
A lens moving mechanism, wherein the spring member is disposed between the holder and the rotor cap.

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