JP2007140396A - Drive device for camera lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive device for a lens, the drive device being designed so as to stabilize the original position of the lens. <P>SOLUTION: A motor unit 30 is formed so as to have a structure in which a plate cam 29 is fixed to the output shaft 28 of a flat type stepping motor 21 and the cam 29 is locked by the flange 27a1 of an assembly support post 27a. The cam 29 of the motor unit 30 is rotated, and thereby the roller of a frame unit disposed in contact with the roller operating face 29b of the cam is moved along the rotation of the cam 29. Then, a lens barrel directly connected with the roller and the lens disposed in the lens barrel are driven. The position in which the cam 29 is locked by the assembly support post 27a serves as the original lowest position of the lens. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a camera lens driving device, and more particularly to a driving device for driving a lens by a flat stepping motor and a cam.

  In recent years, mobile phones incorporating ultra-small cameras have become widespread. In addition, there is a demand for higher functionality even in such cameras, and some cameras with functions such as a zoom function, a moving image function, and a continuous shooting function in addition to an autofocus function have appeared. These functions are obtained by downsizing a focus function and a zoom function device, which are generally employed in still cameras and video cameras, into a mobile phone.

  As an apparatus having such a function, an apparatus that drives a lens using a flat stepping motor and a cam can be cited. Hereinafter, a lens driving structure using a flat stepping motor and a cam in a mobile phone will be briefly described with reference to FIGS.

  FIG. 8 shows a driving structure of a lens in the prior art, and shows a cross-sectional view of the main part by taking up only main component parts. FIG. 9 is a perspective view of the frame unit containing the lens barrel and the lens in FIG. 8, and also shows the arrangement of the cams of the motor unit for easy understanding. FIG. 10 is a perspective view of the motor unit in FIG. 8, and FIG. 11 is a perspective view of the frame unit for explaining the origin position of the lens, and also shows the arrangement of the cams of the motor unit for easy understanding.

  The lens driving structure is such that the lens unit is driven by combining the frame unit 20 and the motor unit 10. As shown in FIGS. 8 and 9, the frame unit 20 has a substantially quadrangular prism shape and a round hole formed at the center thereof, and an inner diameter surface 15 a of the hole of the frame 15. And a lens barrel 11 having a pipe shape that slides along the inner diameter surface 15a and at least one lens fitted and arranged on the inner diameter surface 11a of the lens barrel 11 (in FIG. 13 a and 13 b) and a roller 12 provided on the slide overhanging portion 11 b of the lens barrel 11 and projecting outside the frame 15.

  The frame 15 is provided with a slide groove 15b leading to the outside, and the slide pin 14 is embedded in the groove 15b. Also. In order to slide the lens barrel 11 back and forth along the light incident direction A, a slide projecting portion 11b is formed in a part of the outer shape of the lens barrel 11, and a small hole 11c is provided at the slide projecting portion 11b. ing. The small hole 11c and the slide pin 14 are engaged with each other so that the slide projecting portion 11b slides up and down along the slide pin 14. In the groove 15 b of the frame 15, the lens barrel 11 moves up and down as the slide overhanging portion 11 b moves up and down along the slide pin 14. At the same time, the lenses 13 a and 13 b disposed in the lens barrel 11 move up and down. It moves in the direction of light (before and after the light incident direction A). In addition, the roller 12 is attached to one place of the slide projecting portion 11b so as to project outside the frame 15. The roller 12 is constantly urged downward by a spring (not shown). Therefore, the lens barrel 11 directly connected to the roller 12 is also acted on by a downward force. The frame 15 is provided with mounting holes 15d for the motor unit 10 at three corners on the side surface on which the groove 15b is provided. The motor unit 10 is attached to the frame unit 20 through the attachment hole 15d. Further, the frame 15 is provided with a frame stopper 15c that protrudes at one corner on the side where the groove 15b is provided. This frame stopper 15c is provided to stop a cam, which will be described later, and is also used to set the origin position for lens movement.

  On the other hand, as shown in FIGS. 8 and 10, the motor unit 10 includes a stepping motor 1 and a plate-like cam 9 attached to the output shaft 8 of the stepping motor 1.

  As shown in FIG. 10, the stepping motor 1 is a flat and substantially square shape, and between the receiving plate 5 and the ground plate 6, a train of wheels such as a rotor, a yoke, and a plurality of gears (all shown). Although not shown in the figure, 2a and 2b indicate gear wheels of the train wheel). In addition, the coil 4 is disposed at the upper and lower cutouts of the receiving plate 5 and the base plate 6. And these component parts have comprised the structure assembled via the four assembly support | pillars 7a and 7b of four corners. Here, the three assembly columns 7b are projected to the surface side of the main plate 6, and the projecting portions are press-fitted into the mounting holes 15d of the frame 15 so that the frame unit 20 and the motor unit 10 are assembled. It has become. One assembly support column 7a is provided flush with the surface of the main plate 6. Further, an output shaft 8 is arranged in connection with the train wheel, and the output shaft 8 protrudes to the outside of the main plate 6.

  A plate-shaped cam 9 is fixed to the output shaft 8 of the stepping motor 1 to complete the motor unit 10. The cam 9 rotates with the rotation of the output shaft 8.

  FIG. 9 is a perspective view of the frame unit 20, but the arrangement of the cam 9 of the motor unit 10 is also indicated by oblique lines for easy understanding. As shown in FIG. 9, the cam 9 fixed to the output shaft 8 of the stepping motor 1 has a stopper portion 9a and a roller operating surface 9b. The stopper portion 9a is provided to come into contact with the lower surface 15c1 of the frame stopper 15c provided on the frame 15 to make the cam 9 stationary. Here, FIG. 11 shows a state where the stopper portion 9a of the cam 9 abuts against the lower surface 15c1 of the frame stopper 15c and stops. The roller operating surface 9b is in contact with the roller 12 of the frame unit 20, and the lens disposed in the lens barrel 11 is moved up and down at a predetermined speed by operating the roller 12 up and down according to the rotation of the cam 9. Provided to move. The roller operating surface 9b is provided only in a required range portion, and the shape of the other range portion is an appropriate shape in consideration of the influence of contact with other components, lightness, strength, etc. taking it.

  Next, the lens driving device configured as described above drives the lens as follows. First, start from the state of FIG. That is, the cam 9 is stopped when the stopper portion 9a of the cam 9 abuts against the lower surface 15c1 of the frame stopper 15c of the frame 15. At this time, the lenses 13a and 13b are at the origin position in the lowest position. Next, the output shaft 8 of the stepping motor 1 is rotated by a required angle by a drive signal from a control circuit (not shown) based on the focal length data signal with the automatically determined subject, and simultaneously fixed to the output shaft 8. The cam 9 is rotated by a required angle (in the direction of the arrow in FIGS. 9 and 11). The rotation of the cam 9 pushes the roller 12 in contact with the roller operating surface 9b of the cam 9 upward by a required amount. Then, the lens barrel 11 to which the roller 12 is fixed moves by a required amount, and at the same time, the lenses 13a and 13b disposed on the lens barrel 11 also move by the required amount. In this way, the lens is moved and focused. After the shotter is pressed and the photo shoot is finished, the stepping motor 1 is automatically driven and the cam 9 rotates in the reverse direction, the stopper portion 9a of the cam 9 hits the frame stopper 15c of the frame 15, and the cam 9 The stepping motor 1 stops. Simultaneously with the reverse rotation of the cam 9, the roller 12 also follows the cam 9 and descends, and the lens barrel 11 and the lenses 13 a and 13 b connected to the roller 12 simultaneously descend and return to the origin position.

  The conventional lens driving device having the above structure has the following problems. As one of them, the stationary position of the cam 9 is determined by the abutment of the frame 15 with the frame stopper 15c, and the origin position of the lens is set based on the position, but the shape and dimensional accuracy of each part, the motor Due to the dimensional accuracy in assembling the unit 10 and the frame unit 20, the variation in the origin position of the lens appears greatly. In addition, since the frame 15 is formed of a plastic material, wear or the like also occurs at the site of contact with the cam during long-term use, and the lens origin position changes.

  For this reason, in order to correct variations in the accuracy of the origin position of the lens due to unit assembly and changes in the origin position due to wear of the contact portion, it is necessary to perform correction by attaching an origin sensor. In addition, since the origin sensor is provided, the cost is increased.

  As part 2, protrusions such as a rotor cup seat and a gear shaft of the train wheel appear on the surface of the base plate 6 of the stepping motor 1. The necessary amount of the cam 9 and the base plate 6 is necessary to avoid contact with these protrusions. The cam 9 is attached with a gap of. For this reason, the motor unit 10 becomes thick and cannot be thinned.

  The present invention has been made in view of the above problems. As a means for solving this problem, the camera lens driving device according to the present invention is characterized in that a roller fixed to the output shaft of a flat type stepping motor is rotated to contact a roller. In the camera lens driving device that drives the lens barrel through the lens barrel, a cam stopper portion is provided in a part of the stepping motor, and the cam stopper portion and the cam are engaged with each other. Thus, the origin position of the lens is set.

  The camera lens driving device according to the present invention is characterized in that the cam stopper portion is provided on an assembly column of the stepping motor.

  The camera lens driving device according to the present invention is characterized in that the assembly column has a flange portion, and the flange portion serves as the cam stopper portion.

  The camera lens driving device according to the present invention is characterized in that the stepping motor to which the cam is fixed is provided with a drop breakage preventing means.

  Further, the camera lens driving device of the present invention is characterized in that the fall damage prevention means comprises a protrusion provided on the stepping motor and a break prevention stopper for the cam that is locked by the protrusion. It is a feature.

  As an effect of the invention, a cam stopper is provided in a part of the stepping motor provided with the cam, and the cam is locked by the cam stopper, so that the cam can be locked in the same unit. it can. Therefore, it is possible to set the cam locking position without being affected by the assembly accuracy between the motor unit and the frame unit as in the prior art, and to set the locking position with high accuracy. This makes it possible to set the origin position of a lens with little position variation. In addition, since the accuracy of the origin position of the lens is improved, the origin sensor that has been conventionally provided is not required, and the cost can be reduced.

  In addition, when the cam stopper portion is provided on the assembly support column, it is not necessary to increase the number of parts, and the assembly work can be the same as in the past. Therefore, the cost can be reduced.

  Further, if the assembly strut is provided with a collar and the collar is a cam stopper, the strength of the strut can be obtained and the strut is made of metal, so that a stable locking position can be obtained with little wear. This produces an effect of stabilizing without changing the origin position of the lens.

  The stepping motor is provided with a drop breakage prevention means. The purpose of this damage prevention means is to prevent damage to the lens barrel or lens by applying a strong shock due to dropping, etc., causing the cam to rotate abnormally and causing damage due to contact between the cam and other components or abnormally pushing up the lens barrel By providing this breakage prevention means, breakage of other components can be prevented. Further, as the breakage prevention means, the stepping motor is provided with a projection, and the cam is provided with a breakage prevention stopper portion that engages with the projection, thereby preventing abnormal rotation of the cam. Since a breakage prevention means can be obtained by providing one protrusion on the base plate of the stepping motor and partially changing the shape of the cam, measures for preventing breakage can be taken with a simple structure and at a low cost.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to FIGS. FIG. 1 shows a cross-sectional view of the main part of only the main component parts in the simple structure of the camera lens driving device according to the embodiment of the present invention. 2 is a perspective view of the motor unit in FIG. 1, and FIG. 3 is a perspective view of the frame unit in FIG. FIG. 3 also shows the cam arrangement of the motor unit for easy understanding.

  The lens driving device according to the embodiment of the present invention is a combination of a frame unit 40 and a motor unit 30. As shown in FIGS. 1 and 3, the frame unit 40 has a substantially quadrangular prism shape and has a frame 35 formed with a round hole at the center thereof, and an inner diameter surface of the hole of the frame 35. Then, a pipe-shaped lens barrel 31 that slides along the inner diameter surface, and at least one lens that is fitted and disposed on the inner diameter surface of the lens barrel 31 (in FIG. 1, lenses 33a and 33b 2) and a roller 32 provided on the slide projecting portion 31b of the lens barrel 31 and projecting outside the frame 35.

  The frame 35 is provided with a slide groove 35b leading to the outside, and a metal slide pin 34 is embedded in the groove 35b. Also. In order to slide the lens barrel 31 back and forth along the light incident direction A, a U-shaped slide projecting portion 31b is formed in a part of the outer shape of the lens barrel 31, and the slide projecting portion 31b is formed at the position of the slide projecting portion 31b. A small hole 31c that engages with the slide pin 34 is provided. The small hole 31c and the slide pin 34 are engaged with each other so that the slide projecting portion 31b slides up and down along the slide pin 34. In the groove 35 b of the frame 35, the lens barrel 31 moves up and down as the slide overhanging portion 31 b moves up and down along the slide pin 34. At the same time, the lenses 33 a and 33 b disposed in the lens barrel 31 move up and down. It moves in the direction of light (before and after the light incident direction A). Further, the roller 32 is attached to one place of the slide projecting portion 31b so as to project to the outside of the frame 35. The roller 32 has a bearing structure, and its outer portion abuts on a roller operating surface of a cam 29 described later and rotates smoothly. The inner shape portion is firmly fixed to the slide projecting portion 31b, and the cam 29 It functions to move the slide overhang 31b up and down along the movement. The roller 32 is constantly biased downward by a spring (not shown). Therefore, the lens barrel 31 directly connected to the roller 32 is also acted on by a downward force. Further, as shown in FIG. 3, the side surface of the frame 35 where the groove 35b is provided is a side surface provided with a step 35f, and the cam 29 of the motor unit 30 is attached when the motor unit 30 described later is attached. Are accommodated in the stepped portion 35f. Further, mounting holes 35d of the motor unit 30 are provided at the four corners of the same side surface. The motor unit 30 is attached to the frame unit 40 through the attachment hole 35d.

  On the other hand, the motor unit 30 includes a stepping motor 21 and a plate-like cam 29 attached to the output shaft 28 of the stepping motor 21 as shown in FIGS.

  As shown in FIG. 2, the stepping motor 21 has a flat and substantially square shape, and a rotor train, a yoke, and a plurality of gear trains (all are shown) between the receiving plate 25 and the base plate 26. Although not shown in the figure, 22a and 22b indicate gear train shafts). In addition, the coil 24 is arranged in the place where the upper and lower cutouts of the receiving plate 25 and the base plate 26 are provided. And these component parts have comprised the structure assembled via the four assembly support | pillars 27a and 27b of four corners. Here, of the four assembly columns, the three assembly columns 27 b slightly protrude outside the main plate 26, and the remaining one assembly column 27 a functions as a cam stopper that stops the rotation of the cam 29. There is no. A portion 27a1 having a slightly larger outer diameter is provided at a position where it comes into contact with the stopper portion 29a of the cam 29 (a region that is shaped like a fish tail and contacts the assembly support column 27a). The collar portion 27a1 and the stopper portion 29a of the cam 29 come into contact with each other, and the cam 29 is locked. The four assembly columns 27a and 27b are press-fitted into the mounting holes 35d at the four corners of the frame 35 to assemble the frame unit 40 and the motor unit 30. Further, an output shaft 28 is disposed in connection with the train wheel, and the output shaft 28 protrudes to the outside of the main plate 26.

  A plate-shaped cam 29 is fixed to the output shaft 28, and the motor unit 30 is completed. The cam 29 rotates with the rotation of the output shaft 28.

  In this embodiment, the cam 29 fixed to the output shaft 28 of the stepping motor 21 has a fish-like shape as shown in FIG. 2, but the cam 29 has the above-described stopper portion 29a and roller operating surface 29b. (The outer surface of the portion painted black and thick in FIGS. 2 and 3) and an opening 29c. The stopper portion 29a is provided to come into contact with the flange portion 27a1 of the assembly post 27a described above to make the cam 29 stationary. The roller operating surface 29b abuts on the roller 32 of the frame unit 40 and operates the roller 32 up and down in accordance with the rotation of the cam 29 to move the lenses 33a and 33b disposed on the lens barrel 31 up and down in a predetermined direction. It is provided to move with speed. This roller operation surface 29b is provided only in a required range portion, and the shape of the outer portion of the other range is an appropriate shape in consideration of the influence of contact with other components, lightness, strength, etc. Is taking. The opening 29c is provided in order to reduce the weight and avoid a significant deviation in cam balance. And this cam 29 rotates in the direction of the arrow.

  Next, a lens driving method of the lens driving device having the above structure will be described with reference to FIG. First, the cam 29 starts with the stopper 29a of the cam 29 abutting against the flange 27a1 of the assembly column 27a and the cam 29 is stationary. At this time, the position where the cam 29 and the roller 32 are in contact with each other is at the lowest position, and the lenses 33a and 33b are at the origin position in the lowest position. Next, the output shaft 28 of the stepping motor 21 is rotated by a required angle by a drive signal from a control circuit (not shown) based on the focal length data signal with the subject automatically determined, and simultaneously fixed to the output shaft 28. The cam 29 is rotated a required angle (in the direction of the arrow in FIG. 3). The rotation of the cam 29 pushes the roller 32 in contact with the roller operating surface 29b of the cam 29 upward by a required amount. Then, the lens barrel 31 to which the roller 32 is fixed moves by a required amount, and at the same time, the lenses 33a and 33b disposed on the lens barrel 31 also move by the required amount. In this way, the lens is moved and focused. After the photographer is finished by pressing the shirter, the stepping motor 21 is automatically driven to rotate the cam 29 in the reverse direction, and the stopper portion 29a of the cam 29 hits the flange portion 27a1 of the assembly column 27a. And the stepping motor 21 stops. Simultaneously with the reverse rotation of the cam 29, the roller 32 is also moved down following the rotation of the cam 29 by the biasing of a spring (not shown), and the lens barrel 31 and the lenses 33a and 33b connected to the roller 32 are also lowered at the same time. Move and return to the home position.

  By adopting the above structure, the locking position of the cam 29 is stabilized, and the origin position of the lens is also stabilized. In the present embodiment, a locking structure is formed by an assembly support column 27a formed of a metal such as brass and a cam 29 formed of a ferrous metal. Further, in order to reduce the influence of the force with which the cam 29 comes into contact, the assembly strut 27a is provided with a flange portion 27a1 having a large diameter and is engaged with the flange portion 27a1. Therefore, the wear of the collar portion 27a1 hardly occurs, and the assembly support column 27a is also firmly fixed to the base plate 26 and the receiving plate 25 made of metal, so that neither deformation nor loosening occurs. As a result, the locking position of the cam 29 does not change, and a stable stationary state is always obtained at the same position. Thereby, a stable origin position can be obtained at the same position of the lens origin position.

  Further, since the abutting force between the cam 29 and the flange portion 27a1 of the assembly support column 27a does not affect the frame 35, the motor unit 30 and the frame unit 40 can be firmly bonded over a long period of time. Therefore, a change in the stationary position of the cam 29 or a change in the lens origin position does not occur over a long period of time.

  Further, in the present embodiment, the assembly support column 27a is used as a cam stopper portion, but this uses an assembly support column that is originally used by changing its shape. Since the number of parts is not newly increased, the lens driving device of the present invention can be obtained at a low cost. Further, the motor unit 30 can be assembled with substantially the same man-hours as before. Furthermore, the assembly of the motor unit 30 and the frame unit 40 is facilitated rather than the conventional structure described in the background art.

  Note that the present invention is not limited to the method using an assembly support as a means for stopping the cam 29. A structure may be adopted in which a protrusion is provided on the ground plate 26 and the protrusion and the cam 29 are locked. For example, a structure in which a slightly thicker pin is disposed on the base plate 26 and the pin and the cam 29 are locked can be exemplified.

  Embodiments of a camera lens driving device according to the present invention will be described below. First, the first embodiment will be described with reference to FIGS. Here, FIG. 4 shows a plan view of the lens driving apparatus according to Embodiment 1 of the present invention, and FIG. 5 shows a sectional view showing only the main part of the DD section in FIG. Parts having the same specifications as those of the component parts in the above-described embodiment will be described with the same reference numerals.

  As shown in FIG. 4, the lens driving device 60 according to the first embodiment includes a frame unit 50 at the center, and two sets of a first motor unit 30-1 and a second motor unit 30-2 on the left and right sides thereof. The motor unit is attached. The first motor unit 30-1 and the second motor unit 30-2 are motor units having the same specifications. However, in order to distinguish the right motor unit from the left motor unit, the first motor unit 30- The first and second motor units 30-2 are distinguished from each other. The first motor unit 30-1 and the second motor unit 30-2 have the same specifications as the specifications of the motor unit 30 in the above-described embodiment, and are used for the output shaft 28 of the stepping motor 21. The fixed cam 29 is locked with the assembly strut of the stepping motor 21. Therefore, since the description of the first motor unit 30-1 and the second motor unit 30-2 has been described in detail in the above-described embodiment, the description here is limited to the necessary limit.

  As shown in FIG. 5, the frame unit 50 incorporates two sets of lens barrels in a hole of a frame 55 having a substantially quadrangular prism shape. One set is a first lens barrel 56 that is slid along the hole diameter surface of the frame 55 and has a pipe shape in which one set of first lenses 58 is disposed on the inner diameter portion. The other set slides along the inner diameter surface of the first lens barrel 56 and moves, and the second lens barrel in the shape of a pipe in which one set of the second lenses 53a and 53b is arranged on the inner diameter portion thereof. 51. The two sets of the first lens barrel 56 and the second lens barrel 51 are separately moved up and down, and the first lens barrel 56 is attached to the right side in the drawing (in FIG. 5). The second lens barrel 51 is driven by a second motor unit 30-2 attached on the left side in the figure (in FIG. 5). A top plate 59 having a round hole at the center is provided on the upper surface of the frame 55. The reflected light beam of the subject enters the lens from the round hole of the top plate 59.

  Hereinafter, these drive structures will be briefly described. In FIG. 5, the frame 55 has a first groove 55b1 and a second groove 55b2 for sliding on the right and left. The first groove 55b1 on the right side is provided to drive the first lens barrel 56 by the first motor unit 30-1, and the first slide pin 54b is embedded in the first groove 55b1. Has been established. The first lens barrel 56 has a U-shaped slide projecting portion 56b in a part of its outer shape, and engages with the first slide pin 54b at the slide projecting portion 56b. A small hole 56c is provided. The first lens barrel 56 moves up and down as the small hole 56c of the slide projecting portion 56b slides smoothly along the first slide pin 54b without play. In addition, a first roller 57 is provided outside the slide projecting portion 56b, and the first roller 57 comes into contact with the cam 29 of the first motor unit 30-1. The first roller 57 has a bearing structure, and its outer portion is in contact with the roller operating surface of the cam 29 and rotates smoothly. The slide overhanging portion 56b is moved up and down along with the movement. The first roller 57 is urged downward from above by a spring (not shown), and a force is always applied to the first roller 57 downward. Accordingly, the first lens barrel 56 connected to the first roller 57 is also exerted with a downward pressing force. The first roller 57 in contact with the cam 29 moves along with the movement of the cam 29, and the first lens barrel 56 moves up and down accordingly. At the same time, the first lens 58 disposed in the first lens barrel 56 also moves up and down. Further, as shown on the left side of FIG. 5, the first lens barrel 56 is provided with a groove 56d so that the slide projecting portion 51b of the second lens barrel 51 can move up and down.

  As shown in FIG. 5, the second groove 55b2 provided on the left side of the frame 55 is provided to drive the second lens barrel 51 by the second motor unit 30-2. A second slide pin 54a is embedded in the second groove 55b2. The second lens barrel 51 has a U-shaped slide projecting portion 51b in a part of its outer shape, and engages with the second slide pin 54a at the slide projecting portion 51b. A small hole 51c is provided. The slide projecting portion 51 b projects from the groove 56 c of the first lens barrel 56 and projects to the second groove 55 b 2 of the frame 55. The second lens barrel 51 moves up and down as the small hole 51c of the slide overhang 51b slides smoothly along the second slide pin 54a without play. Further, a second roller 52 is provided outside the slide projecting portion 51b, and the second roller 52 comes into contact with the cam 29 of the second motor unit 30-2. The second roller 52 has a bearing structure, and its outer portion abuts against the roller operating surface of the cam 29 and rotates smoothly. The inner shape portion is firmly fixed to the slide projecting portion 51b, and the cam 29 The slide overhanging portion 51b is moved up and down along the movement. The second roller 52 is urged downward from above by a spring (not shown), and a force is always applied to the second roller 52 downward. Accordingly, the second lens barrel 51 connected to the second roller 52 is also exerted with a force of pushing down. The second roller 52 in contact with the cam 29 moves along with the movement of the cam 29, and the second lens barrel 51 moves up and down accordingly. At the same time, the pair of second lenses 53a and 53b disposed in the second lens barrel 51 also move up and down.

  As described above, the first lens barrel 56 provided in the frame 55 is driven by the first motor unit 30-1, whereby the first lens 58 provided in the first lens barrel 56 is driven. Similarly, the second lens barrel 51 provided in the frame 55 is driven by the second motor unit 30-2, whereby the second lenses 53a and 53b provided in the second lens barrel 51 are driven. To do. In the first embodiment, the focal length is adjusted by the first lens 58 provided in the first lens barrel 56, and the zoom function is achieved by the second lenses 53a and 53b provided in the second lens barrel 51. Has a zoom camera.

  By taking the above configuration, a lens driving device having two functions can be obtained. And the motor unit which has the structure of the present invention explained in the above-mentioned embodiment is used in the drive device. Therefore, the same effect as that obtained in the above-described embodiment can be obtained in Example 1. In other words, as described in the above-described embodiment, the locking structure of the cam 29 fixed to the output shaft 28 of the stepping motor 21 is related to the assembly column firmly fixed to the stepping motor 21 made of metal. Has a structure to stop. Furthermore, the part of the assembly support column with which the cam 29 abuts is adapted to abut against the flange portion having a larger diameter. For this reason, even if the force of abutment of the cam 29 is generated, the locking portion is hardly deformed, and the assembly strut is not deformed or loosened. Therefore, a stable stationary state at the same position is always obtained without changing the locking position of the cam 29. Further, the first lens barrel 56 driven by the first motor unit 30-1 having such a locking structure of the cam 29 is fixed to the slide projecting portion 56b of the first lens barrel 56. The first lens barrel 56 is driven by the cam 29 because the first roller 57 is firmly fixed to the first lens barrel 56. Stable driving is performed along the movement of the. When the cam 29 comes into contact with the assembly column and stops, the first lens barrel 56 comes to the lowest position and stops in a stable state. As a result, the origin position of the first lens 58 is constantly obtained at the same position.

  Similarly, the second lens barrel 51 driven by the second motor unit 30-2 is also driven stably, and the origin positions of the second lenses 53a and 53b are constantly stable at the same position. A position is obtained.

  With the above, you will be able to take beautiful photo images in focus.

  Next, a second embodiment of the camera lens driving device of the present invention will be described with reference to FIGS. 6 shows a plan view of a lens driving apparatus according to Embodiment 2 of the present invention, and FIG. 7 shows a perspective view of the lens unit in FIG. Parts having the same specifications as the component parts in the first embodiment and the above-described embodiment will be described with the same reference numerals.

  As shown in FIG. 6, the lens driving device 80 according to the second embodiment includes a frame unit 50 at the center, and two sets of a first motor unit 70-1 and a second motor unit 70-2 on the left and right sides thereof. The motor unit is attached. The first motor unit 70-1 and the second motor unit 70-2 are motor units having the same specifications, but in order to distinguish the right motor unit from the left motor unit, the first motor unit 70- The first motor unit 70-2 is distinguished from the first motor unit 70-2. The frame unit 50 has the same specifications as the frame unit of the first embodiment.

  The first motor unit 70-1 and the second motor unit 70-2 have the configuration of the motor unit 70 shown in FIG. As shown in FIG. 7, the motor unit 70 has a configuration in which a plate-like cam 69 is fixed to the output shaft 28 of the stepping motor 61. Here, the stepping motor 61 is provided with a breakage prevention stop pin 63 at one location of the base plate 26 of the stepping motor used in the above-described embodiment. Further, the cam 69 fixed to the output shaft 28 of the stepping motor 61 has a shape different from the shape of the cam used in the above-described embodiment. The cam 69 comes into contact with the flange 27a1 of the assembly support column 27a and stops, a roller operating surface 69b (a region of a thick black portion in the drawing) where it contacts the roller of the frame unit, and an opening. The portion 69c and the main portion of the breakage prevention stopper portion 69d are formed. The feature of the motor unit 70 here is that it has a damage prevention structure in addition to the features of the motor unit of the above-described embodiment, and avoids the place where the shafts 22a and 22b of the gears slightly protruding on the surface of the main plate 26 are present. Thus, the mounting method and shape are such that the cam 69 rotates.

  The breakage prevention structure applies an abnormal force to the cam or motor when the device is dropped, causing a rotation angle greater than the normal rotation angle and colliding with other components, damaging that part, or hitting the cam. It is provided in order to prevent damage caused by applying an abnormal force to the roller on the frame side in contact with the frame and causing damage to the parts on the frame side. The breakage prevention structure according to the second embodiment achieves a breakage prevention function with the configuration of the breakage prevention stop pin 63 provided on the stepping motor 61 and the bankruptcy prevention stopper portion 69d provided on the cam 69. A breakage prevention stop pin 63 is provided on the base plate 26 at a position that does not affect parts such as a train wheel, and the cam 69 stops against the pin 63 to prevent the cam 69 from rotating abnormally.

  In the second embodiment, the breakage prevention means is taken by the locking structure of the protrusion of the breakage prevention stop pin 63 and the breakage prevention stopper 69d of the cam 69. However, the breakage prevention means is not limited to this structure. Other damage prevention structures may be used.

  Next, the abutting portion of the cam that abuts on the roller moves along the rotation of the cam, and the moving direction of the abutting portion moves in the direction opposite to the rotating direction of the cam. Further, in the locking structure that is locked by the cam and the assembly strut provided at the corner of the stepping motor, the length of the cam is the longest at the position where the stopper portion that hits the assembly strut is provided. If this long part is attached so as to rotate away from the gear shaft of the train wheel, contact with the gear shaft of the train wheel slightly protruding from the surface of the main plate can be avoided.

  That is, in FIG. 7, when the cam 69 is arranged to rotate in the direction of the arrow, the cam 69 can be designed so as not to approach the rotor cup seat and the gear shafts 22 a and 22 b. And it can avoid that the cam 69 contacts the cup seat and gear shaft 22a, 22b of the rotor which has protruded from the surface of the main plate 26. FIG. By adopting such a method, the mounting height of the cam to the output shaft 28 can be lowered without considering the amount of protrusion of the rotor cup seat and the gear shafts 22a and 22b. As a result, the thickness of the motor unit 70 can be reduced, and the effect of narrowing the width of the lens driving device can be obtained.

  By adopting the above structure, in addition to the stability effect of the lens origin position, it is possible to obtain the effect of preventing damage, the thinning of the motor unit, and the narrowing of the lens driving device.

  Since the frame unit 50 in the second embodiment has the same specifications as the frame unit in the first embodiment, the description of the frame unit 50 is omitted here.

It is sectional drawing of the principal part which picked up and showed only the main component components by the simple structure of the drive device of the camera lens which concerns on embodiment of this invention. It is a perspective view of the motor unit in FIG. FIG. 2 is a perspective view of the frame unit in FIG. 1, but shows an arrangement state of a cam of the motor unit for easy understanding. It is a top view of the drive device of the lens concerning Example 1 of the present invention. It is sectional drawing which showed only the principal part of the DD cross section in FIG. It is a top view of the drive device of the lens concerning Example 2 of the present invention. It is a perspective view of the motor unit in FIG. FIG. 7 is a cross-sectional view of a main part showing only a main component part, showing a lens driving structure in the prior art. FIG. 9 is a perspective view of the frame unit in which the lens barrel and the lens are accommodated in FIG. 8, but also shows the arrangement state of the cam of the motor unit for easy understanding. It is a perspective view of the motor unit in FIG. It is a perspective view of the frame unit for explaining the origin position of the lens, but also shows the arrangement state of the cam of the motor unit for easy understanding.

Explanation of symbols

21, 61 Stepping motors 22a and 22b Gear shaft 24 Coil 25 Receptacle plate 26 Base plate 27a and 27b Assembly support column 27a1 Eaves portion 28 Output shaft 29 and 69 Cam 29a and 69a Stopper portion 29b and 69b Roller operating surfaces 29c and 69c Opening portion 30 70 Motor units 30-1, 70-1 First motor unit 30-2, 70-2 Second motor unit 31 Lens barrels 31b, 51b, 56b Slide projecting portions 31c, 51c, 56c Small hole 32 Roller 33a, 33b Lens 34 Slide pin 35, 55 Frame 35b, 56d Groove 35d Mounting hole 35f Stepped portion 40, 50 Frame unit 51 Second lens barrel 52 Second roller 53a, 53b Second lens 54a Second slide pin 54b Second 1 slide pin 55b1 first groove 55b2 second groove 5 The first barrel 57 the first roller 58 drives 63 breakage preventing stop pin 69d breakage preventing stopper portion of the first lens 59 top plate 60, 80 lenses

Claims (5)

In a camera lens driving apparatus that rotates a cam fixed to an output shaft of a flat type stepping motor and drives a lens barrel through a roller in contact with the cam to drive a lens in the lens barrel. A camera lens driving device, wherein a cam stopper portion is provided in a part of the stepping motor, and an origin position of the lens is set by a locking position between the cam stopper portion and the cam. The camera lens driving device according to claim 1, wherein the cam stopper portion is provided on an assembly column of the stepping motor. The camera lens driving device according to claim 1, wherein the assembly column includes a flange portion, and the flange portion serves as the cam stopper portion. 4. The camera lens driving device according to claim 1, wherein a drop breakage preventing means is provided in the stepping motor to which the cam is fixed. 6. The apparatus for driving a camera lens according to claim 5, wherein the drop damage prevention means comprises a projection provided on the stepping motor and a break prevention stopper of the cam that is locked by the projection. .

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