JP2007310023A - Lens driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain the buckling of a spring member for suspending a lens holder by preventing the rotation of the lens holder to a fixing member in a buckling direction of the spring member caused when falling. <P>SOLUTION: A first annular member 18 where a plurality of ridge parts 18k projecting in a radial direction are formed is attached to the outer periphery part of the lens holder 12, and a second annular member 19 where valley parts 19k opposed to the first annular member 18 are formed is attached to each inner periphery side of the fixing member (a yoke 15 and a lower casing 16B). The ridge part 18k and the valley part 19k are formed so that the slope of the ridge part 18k and the slope of the valley part 19k abutting when the lens holder 12 is decentered to the fixing member side may be slopes 18a and 19a abutting when the lens holder 12 relatively rotates to the fixing member in a direction where a connection part 17n on the holder side and a connection part 17m on the fixing member side of the spring members 17A and 17B are approach to each other. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a drive device for an objective lens such as a camera, and more particularly to a lens drive device using a voice coil motor.

FIG. 7 is a diagram showing a configuration example of a lens driving device using a conventional voice coil motor used for a small portable camera, for example. The lens driving device 50 includes a U-shaped cylindrical yoke 51 made of a magnetic material such as soft iron, a ring-shaped magnet 52 attached to the inner wall of the yoke 51, a lens holder 54 for holding a lens 53, and A drive coil 55 attached to the lens holder 54, a base 56 to which the yoke 51 is attached, a frame 57 for supporting the base 56, and a substantially annular spring member 58A for supporting the lens holder 54 above and below, respectively. , 58B and two caps 59A, 59B covering the upper and lower sides of the spring members 58A, 58B, and the upper spring member 58A is fixed between the uppermost part of the lens holder 54 and the frame 57. The lower spring member 58B is fixed between the bottom of the lens holder 54 and the base 56.
The spring members 58A and 58B are the same product made of a metallic leaf spring such as phosphor bronze having the same shape, and as shown in FIG. 8, each 120 ° formed on the inner peripheral side of the leaf spring. The notched groove 58k is divided into an inner peripheral portion 58a and an outer peripheral portion 58b, and an arc-shaped connecting portion 58c that connects the inner peripheral portion 58a and the outer peripheral portion 58b. The inner peripheral portion 58a and the outer peripheral portion 58b of the spring members 58A and 58B are respectively fixed to the lens holder 54 and the base 56 and the frame 57 which are fixing members, and three arc-shaped connecting portions 58c are connected to the lens holder 54. It has a function of a spring member that movably supports the fixed portion (the frame 57 and the base 56). In order to eliminate the eccentricity of the lens holder 54 at the time of movement, these arc-shaped connecting portions 58c generally have a direction from the connecting portion on the lens holder side to the connecting portion on the fixing member side as shown in FIG. Are all clockwise (or counterclockwise) (see, for example, Patent Documents 1 and 2).
JP 2004-280031 A JP 2005-128405 A

By the way, since a small portable camera can be easily carried around, it receives a large impact force by dropping it when carrying it. When such an impact force such as dropping acts on the lens driving device 50, the lens holder 54 may be decentered and displaced laterally, and may collide with the fixed member. When the lens holder 54 rotates with respect to the fixed member in a direction in which the connecting portion on the holder side of the spring members 58A and 58B and the connecting portion on the fixed member side approach with the impact of the collision, A large compressive stress is applied to the spring members 58A and 58B. Therefore, the spring members 58A and 58B are buckled and deformed plastically.
Specifically, as shown in FIGS. 9A and 9B, when the lens driving device 60 falls on the side surface 60a in a slightly oblique direction and collides with the ground 70 (side surface dropping). As shown in FIG. 9C, after the collision, the fixing member 61 rotates around an axis extending in a direction parallel to the vertical direction, but the lens holder 62 does not rotate due to inertia. Compressive stress is applied to the upper and lower spring members 63a and 63b that suspend the spring, causing buckling.
On the other hand, as shown in FIGS. 10A and 10B, even when the lens driving device 60 drops its front surface 60b in a slightly oblique direction (front surface dropping), the lens holder 62 is on the lens opening side. , The upper and lower spring members 63a and 63b buckle because they rotate about an axis extending in a direction perpendicular to the vertical direction with respect to the fixed member. Further, as shown in FIG. 11, when the lens driving device 60 falls from the corner portion 60c, the fall can be broken down into the side drop and the front drop, so that the rotation of the lens holder 62 around the two axes ( The upper and lower spring members 63a and 63b are buckled and plastically deformed due to the relative rotation with respect to the fixing member and the upward movement.

  The present invention has been made in view of the conventional problems, and prevents the rotation of the spring member in the buckling direction with respect to the fixing member of the lens holder that occurs when the lens holder is dropped, etc. An object of the present invention is to provide a lens driving device capable of suppressing buckling.

  The invention according to claim 1 of the present application includes a holder for holding a lens, a fixing member disposed on the outside of the holder, and a plurality of substantially arc-shaped connecting portions respectively connecting the holder and the fixing member. And a spring member having a spring member that is clockwise or counterclockwise in all directions from the connection portion on the holder side to the connection portion on the fixing member side of each of the coupling portions. A first annular member having at least three ridges projecting in the radial direction is attached to the outer peripheral portion of the holder, and each of the first annular members is positioned at a position facing the annular member of the fixing member. A second annular member having a trough formed so as to face the peak is attached, and a slope of the peak of the first annular member that contacts when the holder is eccentric to the fixing member side and the first Of the two annular members So that the slope of the portion is the slope that comes into contact when the holder rotates relative to the fixing member in a direction in which the connection portion on the holder side and the connection portion on the fixing member side approach each other. This is characterized in that a part and a valley part are formed.

  According to a second aspect of the present invention, a holder for holding a lens having a lens opening on the upper side, a fixing member disposed outside the holder, and the holder and the fixing member are connected to each other. A spring member having a plurality of substantially arc-shaped connecting portions, and the direction from the connecting portion on the holder side to the connecting portion on the fixed member side of each connecting portion is clockwise or counterclockwise. A stopper member having at least three crests protruding toward the holder is attached to the upper side of the holder of the fixing member, and the stopper is attached to the upper side of the holder. Attaching a contact member having a trough formed to face each peak, and a slope of the peak of the stopper member that contacts when the contact member moves to the stopper side The slope of the valley portion of the contact member is the slope that comes into contact when the holder rotates relative to the fixing member in a direction in which the connection portion on the holder side and the connection portion on the fixing member side approach each other. Thus, the above-mentioned peak and valley are formed, respectively.

  According to the present invention, in a lens driving device including a spring member having a substantially arc-shaped connecting portion that connects a holder for holding a lens and a fixing member, the outer peripheral portion of the holder projects in a radial direction. A first annular member formed with a plurality of peak portions is attached, and a trough portion is formed at a position facing the annular member of the fixing member so as to face the peak portion of the first annular member. The second annular member is attached, and the slope of the peak portion of the first annular member and the slope of the valley portion of the second annular member that contact when the holder is eccentric to the fixed member side are the holder side. The crests and troughs are formed so as to be inclined surfaces that come into contact when the holder rotates relative to the fixing member in a direction in which the connecting part on the fixing member side approaches the connecting part on the fixing member side. As a result, a side drop as shown in FIG. In this case, the holder can be rotated with respect to the fixing member in a direction in which the holder-side connecting portion of the spring member is separated from the fixing member-side connecting portion by a repulsive force when the inclined surfaces come into contact with each other. . Accordingly, the holder can be prevented from rotating in the direction in which buckling of the spring member occurs (relative rotation with respect to the fixed member), so that the buckling of the spring member can be suppressed and the durability of the lens driving device can be improved. Can be improved.

  Further, a stopper member formed with a plurality of crests protruding toward the holder side is attached to the upper side of the holder of the fixing member, and is formed on the upper side of the holder so as to face the crest portion of the stopper. The abutting member having a trough is attached, and the slope of the crest of the stopper member that abuts when the abutting member moves to the stopper side and the slope of the trough of the abutting member are on the holder side. The crests and troughs are formed so as to be inclined surfaces that come into contact when the holder rotates relative to the fixing member in a direction in which the connecting part on the fixing member side approaches the connecting part on the fixing member side. Since the rotation of the holder in the direction in which the buckling of the spring member occurs when the front surface is dropped as shown in FIG. 10 can be prevented, the buckling of the spring member can be suppressed and the durability of the lens driving device can be reduced. Can improve .

Hereinafter, the best mode of the present invention will be described with reference to the drawings.
Best Mode
FIG. 1 is a diagram showing a configuration of a lens driving device 10 according to the best mode 1 of the present invention, in which 11 is a lens, 12 is a lens holder for holding the lens 11, and 13 is a lens holder 12. An annular drive coil disposed on the outer peripheral side, 14 is provided on the outer peripheral side of the drive coil 13, a cylindrical magnet for applying a radial magnetic field to the drive coil 13, and 15 is a cross section made of a magnetic material such as soft iron. Is an L-shaped yoke, 16A and 16B are upper and lower casings for supporting the magnet 14 and the yoke 15, and 17A is an upper side which is the lens opening side of the lens holder 12 and the upper casing 16A. The upper spring member 17B is a lower spring member having a shape similar to that of the upper spring member 17A for connecting the lower side of the lens holder 12 and the lower casing 16B. That. The spring members 17A and 17B are spring members having a substantially arc-shaped connecting portion made of a metallic leaf spring such as bronze as shown in FIG. 8, for example. The spring members 17A and 17B have arc-shaped connection portions. The connecting portion is also formed in a clockwise or counterclockwise direction from the connecting portion on the lens holder 12 side to the connecting portion on the fixing member side (see FIG. 2).
Reference numerals 18 and 18 denote first annular members provided on the outer periphery of the upper and lower sides of the lens holder 12, respectively, and 19 and 19 denote an upper side of the yoke 15 as a fixing member and an inner side of the lower casing 16B. It is the 2nd annular member provided in each of the circumference side so that the above-mentioned 1st annular members 18 and 18 may be countered.

FIG. 2 is a diagram showing details of the first annular member 18 provided on the lower side of the lens holder 12 and the second annular member 19 provided on the inner peripheral side of the lower casing 16B, and the positional relationship thereof. The first annular member 18 is formed with a plurality of (here, three) crests 18k protruding in the radial direction, that is, the second annular member 19 side, and the second annular member 19, a valley portion 19k is formed so as to face the peak portion 18k of the first annular member 18. The mountain portion 18k has two slope portions 18a and 18b toward the apex of the mountain portion 18k, while the valley portion 19k has two slope portions 19a and 19b toward the bottom portion of the valley portion 19k. is doing.
When the lens holder 12 is decentered toward the fixed member and the first annular member 18 approaches the second annular member 19, the slope 18a of the peak 18k and the slope 19a of the valley 19k, or Any of the slopes 18b and 19b abut against each other. In the present invention, as shown in the enlarged view of the main part of FIG. On the other hand, when the holder-side connecting portion 17m of the spring member 17B (or the spring member 17A) and the connecting portion 17n on the fixed member side are relatively rotated in the approaching direction, the inclined surface comes into contact. The peak portion 18k and the valley portion 19k are formed. Specifically, when the lens holder 12 rotates relative to the direction in which the holder-side connecting portion 17m of the spring member 17B and the fixing-member-side connecting portion 17n approach each other, the inclined surfaces 18a and 19a that are in contact with each other The peak part 18k and the valley part 19k are formed so that the gap g is narrower than the gap G between the other slopes 18b, 19b.
The positional relationship between the first annular member 18 and the second annular member 19 is such that the unevenness of the first annular member 18 and the unevenness of the second annular member 19 are substantially the same type, and This can be easily realized by shifting the center of the peak portion 18k and the center of the valley portion 19k by a predetermined angle in the circumferential direction.

When the uneven state of the first annular member 18 and the uneven state of the second annular member 19 are formed as described above, when the lens holder 12 is decentered toward the lower casing 16B which is a fixed member, the first The slope 18a of the peak portion 18k of the annular member 18 and the slope 19a of the valley portion 19k of the second annular member 18 first come into contact with each other. Therefore, the repulsive force F generated when the inclined surface 18a and the inclined surface 19a collide with each other when the side surface is dropped, as shown by the arrow in the figure, between the holder side connecting portion 17m of the spring member 17B and the connecting portion 17n on the fixed member side. The lens holder 12 acts to rotate with respect to the lower casing 16B as a fixing member in a direction in which the lens holder 12 moves away, that is, a direction in which a tensile force is applied to the lower spring member 17B. Rotation in a direction in which buckling of the lower spring member 17B occurs (actually, in a direction in which the connecting portion 17c is compressed by relative rotation of the lens holder 12 when the lower casing 16B is stationary). Rotation) is hindered by the repulsive force F when the inclined surfaces 18a and 19a are in contact. Thereby, since the buckling of the lower spring member 17B can be suppressed, the durability of the lens driving device 10 can be improved.
Since the first annular member 18 provided on the upper side of the lens holder 12 and the second annular member 19 provided on the upper side of the yoke 15 have the same configuration and positional relationship, the upper spring member 17A Buckling can also be reliably suppressed.

  As described above, according to the best mode 1, the first annular members 18 and 18 in which a plurality of crests 18k projecting in the radial direction are formed on the outer peripheral portions on the upper side and the lower side of the lens holder 12 are provided. A second annular member 19 having a valley portion 19k opposed to the first annular members 18 and 18 formed on the upper side of the yoke 15 as a mounting member and the inner peripheral side of the lower casing 16B, respectively. 19 and the inclined surface of the peak portion 18k and the inclined surface of the valley portion 19k that come into contact when the lens holder 12 is eccentric to the fixing member side, the lens holder 12 holder is relative to the fixing member. The inclined surface 1 that comes into contact with the holder-side connecting portion 17n and the fixing member-side connecting portion 17m of the spring members 17A and 17B that suspend the lens holder 12 when the lens holder 12 is rotated. Since the peak portion 18k and the valley portion 19k are formed so as to be a and 19a, the buckling of the upper and lower spring members 17A and 17B is caused by the repulsive force caused by the collision of the slopes 18a and 19a when the side surface is dropped. Can be prevented from rotating in the direction in which the spring is generated, and the buckling of the spring members 17A and 17B can be effectively suppressed.

In the best mode 1, two sets of the first and second annular members 18 and 19 are provided. However, one set may be provided, or three or more sets may be provided.
In the above example, the peak portion 18k and the valley portion 19k have a gentle shape. However, what is important is that the inclined surfaces 18a contact each other when the lens holder 12 is eccentric toward the fixing member (yoke 15, lower casing 16B). 19a, for example, as shown in FIGS. 3A and 3B, portions other than the slopes 18a and 19a are separated when the slope 18a and the slope 19a come into contact with each other. Any shape may be used as long as it is formed.
Further, as shown in FIG. 4, the peak portion 18 k and the valley portion 19 k may be formed over the entire circumference of the first and second annular members 18 and 19. Also in this case, when the lens holder 12 holder rotates relative to the fixed member, the holder side connecting portion 17n and the fixed member side connecting portion 17m of the spring members 17A and 17B that suspend the lens holder 12 approach each other. If the crest 18k and the trough 19k are formed such that the gap g between the inclined surfaces 18a and 19a that come into contact with each other when rotated in the direction is narrower than the gap G between the other inclined surfaces 18b and 19b. The repulsive force F generated when the inclined surface 18a and the inclined surface 19a collide with each other when the side surface is dropped is, as shown by the arrow in the figure, between the holder side connecting portion 17m of the spring member 17B and the connecting portion 17n on the fixed member side. Since the lens holder 12 acts to rotate away from the lower casing 16B, which is a fixing member, in the direction of moving away, the buckling of the upper and lower spring members 17A, 17B is generated. It is possible to prevent rotation of that direction.
As shown in FIGS. 2 and 3, when the peak 18k and the valley 19k are isolated, the isolated peak 18k and valley 19k are the first and second annular members 18. , 19 is preferably formed at least at three locations on the circumference of the lens holder 19, whereby the lens holder 12 can be sufficiently prevented from rotating when the side surface is dropped.

Best Mode 2
In the best mode 1 described above, the case where the buckling of the upper and lower spring members 17A, 17B is suppressed when the side surface is dropped has been described. However, as shown in FIG. An annular stopper 21 having a plurality of peaks 21k protruding toward the lens holder 12 is attached to the upper casing 16A, which is a fixing member, and is opposed to the peaks 21k of the stopper 21 on the upper side of the lens holder 12. If the contact member 22 having the valley 22k formed to be attached is attached, the buckling of the upper and lower spring members 17A and 17B when the front surface is dropped can be suppressed.
Also in this case, as shown in FIGS. 6A and 6B, the lens holder 12 is placed on the casing 16 </ b> A on the inclined surface that comes into contact when the contact member 22 comes into contact with the stopper 21 due to a frontal drop. On the other hand, the peak portion 21k is formed so that the slopes 21a and 22a come into contact with each other when the holder side connection portion 17m of the spring member 17A and the connection portion 17n on the fixing member side rotate relatively in the approaching direction. It is important to form the valley portion 22k. Specifically, when the lens holder 12 is relatively rotated in a direction in which the holder side connection portion 17m of the spring member 17A and the connection portion 17n on the fixed member side approach each other. The peak portion 21k and the valley portion 22k are formed so that the interval g between the inclined surfaces 21a and 22a, which are the contacted inclined surfaces, is narrower than the interval G between the other inclined surfaces 21b and 22b. As a result, when the lens holder 12 moves to the upper casing 16A side which is a fixed member due to the fall of the front surface, the inclined surface 22a of the contact member 22 and the valley portion 21a of the stopper 21 collide so as to contact each other. The repulsive force F has a component that rotates the lens holder 12 in a direction in which the holder-side connecting portion 17m of the upper spring member 17A is separated from the fixed member-side connecting portion 17n, and therefore the direction in which the upper spring member 17A of the lens holder 12 is compressed. Can be inhibited. Therefore, buckling of the upper spring member 17A can be suppressed even when the front surface is dropped.
Thus, in addition to the first and second annular members 18 and 19, the stopper 21 and the abutting member 22 are attached to the lens driving device 10 so that the upper and lower spring members 17A, If the buckling of 17B is also suppressed, the buckling of the upper and lower spring members 17A and 17B is surely suppressed even when falling from the corner 10c of the lens driving device 10 shown in FIG. can do.

  As described above, according to the present invention, since the rotation of the lens holder in the buckling direction of the spring member that occurs at the time of dropping or the like can be suppressed, the buckling of the spring member that suspends the lens holder is suppressed. The durability of the lens driving device can be improved.

It is a figure which shows the structure of the lens drive device which concerns on the best form 1 of this invention. It is a figure which shows an example of the 1st and 2nd annular member by this invention. It is a figure which shows the other example of the 1st and 2nd annular member. It is a figure which shows the example of the 1st and 2nd annular member in which the peak part and the trough part were each formed over the perimeter. It is a figure which shows the structure of the lens drive device which concerns on the best form 2 of this invention. It is a figure which shows an example of the stopper and contact member by this invention. It is a figure which shows the structure of the conventional lens drive device. It is a figure which shows an example of the spring member which has an arc-shaped movable part. It is a figure for demonstrating the relationship between the holder and fixing member at the time of fall of a lens drive device (side drop). It is a figure for demonstrating the relationship between a holder and a fixing member at the time of fall of a lens drive device (front surface fall). It is a figure which shows a mode that it falls from the corner | angular part of a lens drive device.

Explanation of symbols

10 lens drive device, 11 lens, 12 lens holder, 13 drive coil,
14 magnet, 15 yoke, 16A upper casing, 16B lower casing,
17A 1st spring member, 17B 2nd spring member, 18 1st annular member,
18k mountain, 18a, 18b mountain slope, 19 second annular member, 19k valley,
19a, 19b Tilted slope, 21 stopper, 22 Contact member.

Claims (2)

  A holder for holding the lens, a fixing member disposed outside the holder, and a spring member having a plurality of substantially arc-shaped connecting portions for connecting the holder and the fixing member, respectively, In a lens driving device comprising a spring member whose direction from the connecting portion on the holder side of the coupling portion to the connecting portion on the fixing member side is all clockwise or counterclockwise, the outer peripheral portion of the holder projects radially. The first annular member formed with at least three ridges to be attached is attached, and the valley formed so as to face each of the ridges of the first annular member at a position facing the annular member of the fixing member. A second annular member having a portion is attached, and the slope of the peak portion of the first annular member and the slope of the valley portion of the second annular member that contact when the holder is eccentric to the fixed member side are , Holder side connection That the crests and troughs are formed so as to be inclined surfaces that come into contact when the holder rotates relative to the fixing member in the direction in which the connection part on the fixing member side approaches. A lens driving device.   A spring having a lens opening on the upper side, a holder for holding the lens, a fixing member disposed outside the holder, and a plurality of substantially arc-shaped connecting portions for connecting the holder and the fixing member, respectively. In the lens driving device comprising: a member and a spring member in which the direction from the connection portion on the holder side of each coupling portion toward the connection portion on the fixing member side is clockwise or counterclockwise, A stopper member having at least three ridges protruding toward the holder side is attached to the upper side of the holder of the member, and formed on the upper side of the holder so as to face each ridge of the stopper. The abutting member having a trough is attached, and the slope of the crest of the stopper member that abuts when the abutting member moves to the stopper side and the slope of the trough of the abutting member are The crests and troughs are arranged so that the slopes come into contact with each other when the holder rotates relative to the fixing member in the direction in which the connecting part on the side of the slider approaches the connecting part on the fixing member side. A lens driving device characterized by being formed respectively.

Images