JP2007065220A - Camera module and mobile terminal provided with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera module which has a small-sized and light-weight configuration and is provided with a mechanism capable of accurately detecting a movement distance of a lens, and a mobile terminal provided with the camera module. <P>SOLUTION: In a camera module 20 which has a driving-side shaft member 21 and a guide shaft member 22 inserted through a lens holding part 10 and has the lens holding part 10 constituted so as to be movable in an optical axis direction, a detection part is provided which detects an extent of movement of the lens holding part 10 by moire fringes, and the detection part is installed in such position that a distance from the detection part to the driving-side shaft member 21 is shorter than that to the guide shaft member 22, and a space setting means is provided which projects at least a part of a periphery of a storage part of a camera module main body-side scale member 2 toward a lens holding part-side scale member 1 and brings this part into contact with the lens holding part-side scale member 1 to fix a space between the scale members. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a camera module and a portable terminal including the camera module, and more particularly to a camera module having a small and lightweight structure and a mechanism capable of accurately detecting a lens moving distance and a portable terminal including the camera module. Is.

  Camera modules used in mobile terminals such as recent mobile phones are capable of high-definition photography even with small size due to the increase in the number of pixels of the image sensor (CCD), so that it is similar to a normal electronic camera (digital camera). A high-speed, high-precision autofocus (AF) function and a focal length change (zoom) function are required, and the camera module is inevitably about 10 × 10 × 20 mm due to the miniaturization and weight reduction of the mobile terminal itself. It is desired to be made to the size of.

  In order to change the autofocus and focal length (zoom) in such a camera module, it is necessary to move the lens group in the direction of the optical axis. One cylindrical cam is driven by a motor to drive a zoom lens frame and a focusing lens frame, or a cylindrical cam that is also arranged adjacent to the lens frame is driven by a motor, thereby focusing. For example, a mechanism is used in which the lens frame and the zoom lens frame are moved to switch between tele and wide two points.

  In addition to the cylindrical cam, the autofocus lens frame and zoom lens frame are configured to be driven by the corresponding autofocus lead screw and zoom lead screw, and the lens closest to the subject is fixed to the front of the case. The lead screw is provided at the corner of one side of the case, the lens frame guide support portion is provided in the case, the zoom lead screw is provided in the first quadrant around the optical axis, and the focus lead screw is provided in the second quadrant. There is a camera module configured such that the guide shaft of the lens frame is arranged in the third quadrant, a camera module having a mechanism for moving the lens group in the optical axis direction using a helicoid mechanism, and the like.

  Further, as a drive source for moving the lens frame in the optical axis direction, a piezoelectric element such as a piezo element (PZT) as shown in Patent Document 1, for example, generates mechanical distortion in accordance with a change in an electric field or a magnetic field. There is also a camera using a friction drive type drive source in which a mechanical vibrator is configured and a rotor or a slider is brought into contact with the mechanical vibrator so that the vibration of the mechanical vibrator can be extracted as an output. Such a friction drive type drive source has low torque but high torque and excellent response and controllability, enables fine positioning, has a holding torque (or holding force) when not energized, has excellent quietness, It has advantages such as small size and light weight.

  However, as described above, when the camera module is about 10 × 10 × 20 mm in size, the change in focal length (zoom) and the movement of the lens for focusing require accuracy on the order of 10 to several μm. Is done.

  Conventionally, rotary encoders, linear encoders, magnescales, and the like have been used for high-definition position detection. However, in a camera module that requires a size of about 10 × 10 × 20 mm as described above, this is the case. Such a mechanism is too large to be used.

  On the other hand, in the field of fine processing or a color image forming apparatus that requires delicate color matching, for example, as shown in Patent Document 2 and Patent Document 3, moire fringes are used, thereby measuring dimensions for fine processing. In addition, it is possible to detect inclinations in individual images when superimposing a plurality of color images.

  That is, as shown in FIG. 5 (A), the two scale members of the movable-side scale member 41 and the fixed-side scale member 42 in which the transmissive portions and the non-transmissive portions are alternately formed in a fine pitch at a fine pitch. Are opposed to each other at a short distance, and as shown in FIG. 5B, they are arranged with a slight inclination so that an angle difference of θ ° is generated from a state in which the lattices are parallel to each other.

  Then, as apparent from FIG. 5B, the transmissive portions and the non-transmissive portions interfere with each other, and moire fringes having a pitch sufficiently larger than the pitch of the lattice on the scale member are formed. When the movable scale member 41 is moved, for example, in the direction of the arrow 46 that is the left-right direction in the figure, the interference position between the transmission part and the non-transmission part moves, and the moire fringe moves in the direction indicated by the arrow 47. .

  Therefore, as shown in FIG. 5A, the movable-side scale member 41 and the fixed-side scale member 42 are installed between the photointerrupters 45 having the light-emitting elements and the light-receiving elements indicated by 43 and 44, and moire fringes are formed. Is extracted from the light receiving element 44 as a voltage waveform, so that the minute movement amount of the movable scale member 41 can be enlarged and accurately detected.

Here, P is the pitch of the grating shown in FIG. 5B, W is the pitch of the moiré fringes, and the angular difference from the parallel state of the gratings in the movable scale member 41 and the fixed scale member 42 is shown. Assuming that θ °, the pitch W of moire fringes is expressed by the following equation (1).
W = (Pcos (θ / 2)) / sinθ (1)
Further, in this equation (1), when θ is sufficiently small, the following equation (2) is established.
W = P / θ (θ: radians) ……………… (2)

  As can be seen from the equation (2), the pitch W of the moiré fringes is optically multiplied by 1 / θ (θ: radians) of the pitch P of the grating. When the lattice moves by P in the left-right direction indicated by 46 in the figure in the lattice of the fixed-side scale member 42, the moire fringe moves by W in the up-down direction perpendicular to this. Therefore, it is possible to know the amount of movement of the grating by reading this enlarged change in W, and it is possible to detect a minute movement as a large amount of movement.

Japanese Patent No. 2980541 Japanese Patent Laid-Open No. 11-118422 Japanese Patent Laid-Open No. 10-115955

  However, what is disclosed in Patent Document 2 is for detecting the moving direction during dimension measurement in microfabrication, and there is no description about use in a camera module. The apparatus of Patent Document 3 is also a technique for superimposing images of a plurality of colors in a color image forming apparatus, and similarly there is no description about using it for a minute one such as a camera module.

  Therefore, an object of the present invention is to provide a camera module that has a mechanism that can accurately detect the moving distance of the lens and a portable terminal that includes the camera module.

In order to solve the above problems, the camera module according to the present invention includes:
In a camera module having at least one optical lens and having a lens holding part configured to be movable in the optical axis direction through the drive side shaft member and the guide shaft member.
A detection unit configured to detect an amount of movement of the lens holding unit in the optical axis direction, the detection unit being provided at a periphery of the lens holding unit, and a distance from the detection unit to the driving side shaft member from the detection unit; It is provided at a position smaller than the distance to the guide shaft member, and the amount of movement of the lens holding portion in the optical axis direction is detected by moire fringes.

  In this way, the driving side shaft member and the guide shaft member are inserted, and the movement amount of the lens holding portion configured to be movable in the optical axis direction is detected by the moire fringes, as described above. Since the detection unit can detect a minute movement as a large movement amount, the movement amount can be detected with high accuracy, and the camera module can be configured in a small size.

  In addition, by providing the detection unit at a position where the distance from the detection unit to the drive side shaft member is smaller than the distance to the guide shaft member, the influence on the pitch of the moire fringes generated by the detection unit is minimized. Can do. That is, the tilt of the lens holding portion is normally constant in the driving side shaft member, but the tilt of the lens holding portion is an angle between the movable side scale member 41 and the fixed side scale member 42 for generating the moire fringes described above. May affect the difference. However, when the tilt is constant, the amount of movement of the lens holding portion can always be detected with high accuracy by measuring the moire fringe pitch based on the tilt.

In addition, the camera module according to the present invention to solve the above problems is
In a camera module having at least one optical lens and having a lens holding portion configured to be movable in the optical axis direction through the drive side shaft member and the guide shaft member.
A pair of moire fringe generating scale members disposed opposite to the lens holding unit side and the camera module main body side; and a distance setting means provided between the camera module main body side and the pair of moire fringe generating scale members. And a detection unit that detects the amount of movement of the lens holding unit in the optical axis direction by moire fringes.

  As described above, with the miniaturization of the camera module, the lens stop position accuracy is required to be about 5 μm. Therefore, it is necessary to satisfy this requirement when trying to detect the stop position of the lens for zooming or focusing by moire fringes. In order to satisfy this requirement, for example, the pitch P of the lattice formed on the movable scale member 41 and the fixed scale member 42 shown in FIG. 5B is 20 μm, and the crossing angle θ between the scale members is 1 °. Is set, the pitch W of the moire fringes obtained by the above equation (1) is 1146 μm, and by setting four threshold voltages that divide one period of the waveform into four, position detection in increments of 5 μm can be performed. It becomes possible.

  However, at this time, if the surface interval between the movable scale member 41 and the fixed scale member 42 varies, or if the inclination angle of the lattice in the movable scale member 41 changes depending on the movement direction, the amplitude of the moire waveform varies, and the threshold The position of the holding position varies and the position detection accuracy is significantly lowered. In particular, when the surface spacing varies, the moire fringe spacing varies depending on the position of the lens holding portion, and in the worst case, the moving distance cannot be detected and the position is skipped. The variation in the surface interval between the scale members may be caused by a built-in tolerance up to the component members to which the scale members are attached, a variation in component tolerance, a backlash between components, a warp of the scale member, or the like.

  In particular, if the moire fringe pitch W is set to 20 μm and a small photo-interrupter 45 is to be detected using a sufficiently safe threshold voltage, the surface interval between the scale members must be 50 μm or less. If this is set, the detection accuracy will deteriorate even if the surface spacing is too close. In other words, in this case, it is necessary to fix the surface interval between the movable side scale member 41 and the fixed side scale member 42 to approximately 50 μm, but this requirement is realized in the present situation where there are various variations as described above. Becomes very difficult.

  As a method of making such a surface interval constant, a method such as fixing with an adhesive so as to make the surface interval constant using a jig is common, but such a method requires man-hours, It is not preferable in terms of cost. However, by providing the moire fringe generating scale member interval setting means on the camera module main body side as in the present invention, the pair of scale members can always maintain the same interval, and these problems are avoided. Therefore, it is possible to provide a small camera module having a mechanism that can accurately detect the moving distance of the lens.

  The detection unit includes a pair of moire fringe generating scale members disposed opposite to the lens holding unit side and the camera module main body side, and at least a part of the camera module main body side scale member housing portion around the lens holding unit. And a scale member interval setting means having a contact portion projecting to the side scale member side and contacting the lens holding portion side scale member, and similarly, between the pair of moire fringe generating scale members. The interval setting means accommodates the camera module main body side scale member, and at least a part of the periphery protrudes by a set interval with the lens holding unit side scale member and makes contact with the lens holding unit side scale member The lens holding part side moire fringe generating scale member even if the lens holding part is tilted The interval always by contact to the interval setting means is kept constant, thereby enabling highly accurate displacement detection.

  Furthermore, the lens holding unit side scale member is formed of a flexible resin film, and is attached to the lens holding unit so as to come into contact with the contact unit provided on the camera module main body side. The scale member for generating the side moire fringes always comes into contact with the interval setting means, and even if the lens holding portion is tilted, the interval is kept constant and the movement amount can be detected with high accuracy.

  The lens holding portion is driven by a piezo element whose operating portion is in contact with the drive-side shaft member, so that the piezo element is low in speed but high in torque and has high response and controllability as described above. It has advantages such as excellent positioning, fine positioning, holding torque (or holding force) when no current is applied, excellent quietness, small size and light weight. It is optimal as a drive source for a camera module having a quantity detection means.

Furthermore, according to the present invention to solve the above problems,
A lens holding unit configured to be movable in the optical axis direction by inserting a driving side shaft member and a guide shaft member provided in the camera module body with at least one optical lens;
A detection unit that detects the amount of movement of the lens holding unit in the optical axis direction,
The detection unit includes a pair of moire fringe generation scale members provided on the periphery of the lens holding unit and arranged to face the lens holding unit side and the camera module main body side, and a moire pattern generated by the moire fringe generation scale member. It is configured with a fringe detection means, and a distance from the detection unit to the drive side shaft member is provided at a position smaller than a distance from the detection unit to the guide shaft member,
The camera module main body side scale member is provided with an abutting portion for projecting at least a part of the periphery of the housing portion by a set interval with the lens holding portion side scale member to abut the lens holding portion side scale member. Contained in the containment unit,
The lens holding part-side scale member is formed of a flexible resin film, and is attached to the lens holding part so as to come into contact with the contact part provided on the camera module main body side.
An operation member, a display member, a battery, a communication unit,
A portable terminal including the camera module, the display member, the battery, and a housing that houses the communication unit is obtained.

  As described above, according to the present invention, a mechanism capable of accurately detecting the movement distance of the lens in the camera module is provided with high accuracy, and the camera module can be configured to be small and light. A camera module can be provided.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

  FIG. 1 is an enlarged cross-sectional view of a detection unit that detects a moving distance of a lens holding unit in a camera module according to an embodiment, FIG. 2A is a side view of the camera module of the embodiment, and FIG. FIG. 6 is a cross-sectional view taken along the line AA in FIG. FIG. 3 is a perspective view of the camera module of the embodiment, and FIG. 4 is a diagram schematically showing an example of a mobile phone in which the camera module of the embodiment is incorporated.

  First, the present invention will be briefly described. In the present invention, the lens holding portion having at least one optical lens in the camera module and having the driving side shaft member and the guide shaft member inserted therein is zoomed or focused. When moving along with the alignment, the amount of movement can be detected by a detection unit that generates moire fringes as described with reference to FIG. In this way, as described above, the detection unit using moire fringes can detect a minute movement as a large movement amount, so that it is possible to detect a movement amount with high accuracy, and a camera module. It can be configured in a small size.

  However, as described above, when the size of the camera module itself is about 10 × 10 × 20 mm, the camera module itself becomes large when the detection unit becomes large. It is difficult to make the distance between the side scale member 41 and the fixed side scale member 42 constant, or to use a special jig to keep the crossing angle of the lattices constant.

  However, when the lens holding portion is driven by inserting the driving side shaft member and the guide shaft member as described above, the lens holding portion is tilted to some extent due to manufacturing tolerances, and the movable side scale member 41 is fixed to the fixed side. The angle difference of the lattice of the scale member 42 may change, or it may be difficult to keep the distance between the movable scale member 41 and the fixed scale member 42 constant.

  Therefore, in the camera module of the embodiment, in order to solve this problem, the detection unit is provided at a position where the distance to the driving side shaft member is smaller than the distance to the guide shaft member at the periphery of the lens holding unit.

  By doing so, even if a certain amount of tilting occurs in the lens holding portion, the tilting of the lens holding portion is normally constant on the driving side shaft member side, so that the moire fringes described above are generated. The angle difference between the movable-side scale member 41 and the fixed-side scale member 42 is a constant value including a tilt, and by measuring the moire fringe pitch including the tilt, the amount of movement of the lens holding portion is always highly accurate. It becomes possible to detect.

  Further, as described above, with the miniaturization of the camera module, the lens stop position accuracy is required to be about 5 μm, but the surface interval between the movable scale member 41 and the fixed scale member 42 varies. If there is, the amplitude of the moire waveform varies and the position detection accuracy is significantly lowered. The variation in the surface spacing between the scale members may include a built-in tolerance to the component members to which the scale members are attached, a variation in component tolerance, a backlash between parts, and a warp of the scale member. In order to make such a surface interval constant, a method of fixing with an adhesive so as to make the surface interval constant using a conventional jig requires a man-hour and is not preferable in terms of cost.

Therefore, in the camera module of the embodiment, the interval setting means is provided in order to make the interval between the pair of moire fringe generating scale members, that is, the movable scale member 41 and the fixed scale member 42 constant. In this way, the pair of movable-side scale member 41 and fixed-side scale member 42 can always maintain the same distance, and such a problem is avoided, and the lens is small in size and accurately moves the lens. It is possible to provide a camera module equipped with a mechanism capable of detecting the above.
Hereinafter, the camera module of the embodiment will be described in detail with reference to the drawings.

  FIG. 3 is a perspective view of the camera module 20 of the embodiment. The camera module 20 holds at least one optical lens, and is configured to be movable in the optical axis direction through the drive-side shaft member 21 and the guide shaft member 22 that are attached to the camera module housing 23. Zooming (focal length change) and focusing are performed by moving the lens holding unit 10. The camera module 20 has a fixed lens holding portion 26 holding the lens 24 on the subject side on the subject side, and a CCD or the like on the opposite side of the lens holding portion 10 with respect to the fixed lens holding portion 26. A base 25 incorporating the image pickup element is provided.

2A is a side view of the camera module 20, and FIG. 2B is a cross-sectional view of the position indicated by A-A in FIG. 2A including the moving distance detection unit of the lens holding unit. is there. This camera module 20 uses a piezo element 12 as a drive source of the lens holding unit 10, and the piezo element 12 is formed in a substantially rectangular plate shape as described in detail in Patent Document 1. have been (a driving-side shaft member 21 in the camera module 20 of the embodiment) piezoceramic driven body at one end of the (piezoelectric element) and the actuating portion 12 ₁ is provided with a contact, formed in a longitudinal direction and a lateral direction On the first surface, four electrodes electrically connected with electrodes arranged in a diagonal direction are provided, and one electrode grounded is provided on the entire surface of the second surface on the opposite side.

And a positive voltage to one of the connected electrodes in a diagonal direction on the first surface, by applying a negative voltage to the other, actuating unit 12 ₁ is driven body piezoelectric element 10 is deformed (drive side shaft member intended to drive by using to move relative to 21), this deformation gives a continuously generated such signal voltage, actuating unit 12 ₁ and the driven member (drive side shaft member 21) Since the relative position is displaced, low speed but high torque, excellent response and controllability, minute positioning is possible, and there is a holding torque (or holding force) when no current is applied. It is a drive source having advantages such as being excellent in size, small size and light weight.

  In the following description, the case where the piezo element 12 is used as a driving source of the lens holding unit 10 will be described as an example. However, as described above, the driving side shaft member 21 is used for driving the lens holding unit 10. Of course, it may be driven by a small motor using a screw or a cylindrical cam.

In the camera module 20, a lens 11 including at least one optical lens is disposed at the center of the lens holding portion 10 as shown in the cross-sectional view taken along the line AA in FIG. element 12, the actuating portion 12 ₁ are provided so as to be pressed against the drive-side shaft member 21 by one end spring 13. Further, a guide shaft member 22 is provided at a substantially symmetrical position with the drive side shaft member 21 and the optical axis in between, and the lens holding portion 10 is inserted into the bearing portions 14 and 15 provided in the lens holding portion 10. In 2 (A), it can be moved in the vertical direction. Of course, the installation position of the guide shaft member 22 is not limited to this position.

  Therefore, when the piezo element 12 is driven as described above, the lens holding unit 10 is driven. The amount of movement of the lens holding unit 10 depends on the substrate 27 provided on the housing 23 of the camera module 20. It is detected by the movement amount detector mounted on

As is apparent from the cross-sectional view of FIG. 1 showing the movement amount detection unit in FIG. 2B in an enlarged manner, the movement amount detection unit includes a lens holding unit side scale member (movable side scale member) 1 and a camera. a module body scale member (fixed side scale member) pair of the moire fringes generated for the scale member consisting of 2, is mounted on the substrate 27, the light emitting element 5 ₁ as shown in the 43 and 44 in FIG. 5 (a) and a light receiving element 5 ₂ (positional relationship between the light emitting element 5 ₁ and the light receiving element 5 ₂ may be reversed), the photo provided in the camera module housing 23 so as to sandwich the pair of the moire fringes generated for the scale member It consists of an interrupter 5. The lens holding portion side scale member 1 and the camera module main body side scale member 2 are alternately formed with transmission portions and non-transmission portions in a lattice pattern at a fine pitch as shown in FIG. 5B. , the photo inter Love motor 5 is adapted to the light emitting element 5 ₁ and the light receiving element 5 _2, can detect the contrast of the moiré fringes produced by the lens holding unit side scale member 1, the camera module body scale member 2 .

  In the detection unit having the lens holding unit side scale member 1 and the camera module main body side scale member 2, the lens holding unit 10 to which the lens holding unit side scale member 1 is attached as described above includes the driving side shaft member 21 and the guide. Since the shaft member 22 moves up and down in FIG. 2A or 3 in FIG. 3, the drive side shaft member 21, the guide shaft member 22, and the bearing portions 14 and 15 of the lens holding portion 10. There is a possibility that the lens holding unit 10 may fall to some extent due to manufacturing tolerances.

  Then, first, there is a possibility that the angle difference between the lattices of the lens holding unit side scale member 1 and the camera module main body side scale member 2 may change. In the camera module of the embodiment, in order to solve this problem, the detection unit is provided. The distance to the drive-side shaft member 21 is provided at a position that is smaller than the distance to the guide shaft member 22 at the periphery of the lens holding portion 10.

  The tilting of the lens holding unit 10 may affect the angle difference between the lens holding unit side scale member 1 and the camera module main body side scale member 2 for generating the moire fringes described above. The tilting is normally constant in the drive side shaft member 21, and when this tilting is constant, the movement amount of the lens holding portion can always be detected with high accuracy by measuring the moire fringe pitch including the tilting amount. It becomes.

  That is, the lens holding unit 10 is tilted to some extent by providing the detection unit at a position where the distance to the driving side shaft member 21 is smaller than the distance to the guide shaft member 22 at the periphery of the lens holding unit 10. Even if it occurs, the angle difference between the lens holding unit side scale member 1 and the camera module body side scale member 2 for generating the moire fringes described above is constant including tilting because the detection unit is near the drive side shaft member 21. If the moiré fringe pitch is measured thereby, the amount of movement of the lens holding unit 10 can always be detected with high accuracy.

If the lens holding unit 10 is tilted, the distance between the lens holding unit side scale member 1 and the camera module main body side scale member 2 may vary depending on the position of the lens holding unit 10. On the other hand, the periphery in which the camera module main body side scale member 2 is accommodated is projected toward the lens holding portion side scale member 1 as 3 ₁ , 3 ₂ so that the lens holding portion side scale member 1 can come into contact therewith. Thus, a contact portion 3 serving as an interval setting means is provided so that the lens holding portion side scale member 1 and the camera module main body side scale member 2 are always at a predetermined interval. In addition, the lens holding unit side scale member 1 is formed of a resin film having high flexibility, and the lens holding unit side scale member 1 is brought into contact with the abutting portions 3 ₁ , 3 on the affixing surface 4 provided in the lens holding unit 10. _The problem was solved by sticking to the ₂ side.

That is, since the lens holding unit side scale member 1 always comes into contact with the contact portions 3 ₁ and 3 ₂ even if the lens holding unit 10 falls due to this bending, the lens holding unit side scale member 1 always faces the camera module main body side scale member 2 at regular intervals. In other words, the distance is kept constant and the pitch of the moire fringes does not go wrong, and it is possible to detect the movement amount with high accuracy.

  In addition, even if the lens holding part 10 falls down by installing the detection part on the surface that follows the radial direction orthogonal to the lens optical axis, the lens holding part side scale member 1 and the camera module main body side scale Since the angle difference with the member 2 is a constant value including tilting, the influence on the angle difference between the lens holding unit side scale member 1 and the camera module main body side scale member 2 is reduced, and the detection unit is By installing it on a surface that intersects both the drive side shaft member 21 and the optical axis, it is possible to detect the movement amount of the lens holding portion more accurately.

  Further, if the lens holding unit side scale member 1 is made of fluorine coating or silicon coating, preferably a PET (polyethylene terephthalate) film and has a low coefficient of friction, the lens holding unit side scale member 1 is scraped even if it contacts the interval setting means. Etc. are less likely to occur. Furthermore, at least the lens holding unit side scale member 1 of the lens holding unit side scale member 1 and the camera module main body side scale member 2 is made of polyimide resin film, or Mo3O3, Nb2O5, U3O8, PbTiO3, SrZrO3, SiO2, and TiO2. By using a low expansion coefficient resin film containing any material selected from the group consisting of SiO2 cordierite added in a trace amount, even if the camera module 20 is used in a place exposed to high heat, accurate lens holding is possible. The amount of movement of the part can be detected.

  Further, since the lens holding unit side scale member 1 only needs to be the same as the movable side scale member 41 of FIG. 5 at least at a position facing the camera body side scale member 2, a transparent elastic body (film or the like) is required. ) The lens holding unit side scale member 1 may be affixed only at a position facing the camera body side scale member 2 or the lens holding unit side scale member 1 may be affixed to the tip of the elastic body. May be.

  FIG. 4 is an example of a portable terminal incorporating the camera module 20 configured as described above. The mobile terminal shown in FIG. 4 shows a case of a mobile phone 50 as an example. In the figure, 51 is an operation unit (operation member), 52 is a display (display member), and FIG. 4 is a plan view showing the operation unit (operation member) 51 and the display (display member) 52 visible (open state). In the illustrated mobile phone 50, a first case portion 53 on which an operation portion 51 is mounted and a second case portion 54 on which a display 52 is mounted are connected by a hinge mechanism 55, and the first and first case portions are connected. The two case portions 53 and 54 are rotatable around the hinge mechanism 55. In addition, the 1st and 2nd case parts 53 and 54 comprise a case body.

  The second case 54 incorporates the above-described camera module 20 as indicated by a broken double circle in the drawing, and when a predetermined button of the operation unit 51 is operated, the camera module 20 takes an image, The captured image is displayed on the display 52, for example. The camera module 20 has the upper side shown in FIGS. 2A and 3 facing the outside of the second case portion 54. That is, the second case portion 54 is formed with an opening for exposing the lens held by the fixed lens holding portion 26 in the camera module 20, and although not shown, the first case portion 53 has a battery. In addition, the communication unit and the like are accommodated, and the thickness dimension of the second case portion 54 is substantially regulated to the height of the camera module 20.

  In this way, the driving side shaft member 21 and the guide shaft member 22 are inserted into the lens holding unit 10 to form a camera module and a mobile terminal equipped with the camera module, and the amount of movement of the lens holding unit 10 is moire. By detecting with a detection unit using fringes, it is possible to detect the movement amount with high accuracy, and it is possible to make the camera module and the portable terminal small. In addition, there is a problem that the angle difference between the gratings of the lens holding unit side scale member 1 and the camera module main body side scale member 2 due to the tilting of the lens holding unit 10 which becomes a problem when using moire fringes changes. By providing the detection unit at a position where the distance to the drive side shaft member is smaller than the distance to the guide shaft member at the periphery of the lens holding unit, the influence on the pitch of the moire fringes generated by the detection unit is minimized. Therefore, it is possible to always detect the movement amount of the lens holding unit 10 with high accuracy.

  Regarding the problem that the distance between the lens holding unit side scale member 1 and the camera module main body side scale member 2 may vary depending on the position of the lens holding unit 10 due to the tilt of the lens holding unit 10, A contact portion 3 serving as a distance setting means is provided in the accommodating portion of the side scale member 2, and the lens holding portion side scale member 1 is formed of a flexible resin film or the like so as to always contact the contact portion 3. The problem is solved by affixing the lens holding unit side scale member 1 to the attaching surface 4 of the lens holding unit 10 so that the distance between the lens holding unit side scale member 1 and the camera module main body side scale member 2 is constant. Since the movement amount of the lens holding unit 10 can always be detected with high accuracy, the movement amount of the lens holding unit 10 can always be detected with high accuracy. It is possible.

  According to the present invention, an autofocus (AF) function or a focal length change (zoom) function can be accurately operated in a compact camera module, and a camera module suitable for use in a portable terminal or the like is provided. be able to.

It is sectional drawing to which the detection part which detects the moving distance of the lens holding part in the camera module which becomes embodiment was expanded. (A) is a side view of the camera module of the embodiment, (B) is a cross-sectional view taken along the line AA in (A), and includes a moving distance detection unit of the lens holding unit. It is a perspective view of the camera module of an embodiment. It is a figure which shows roughly an example of the mobile telephone with which the camera module of embodiment was incorporated. To explain a method of detecting a moving distance using moire fringes generated by facing two scale members in which a transmissive portion and a non-transmissive portion are alternately formed in a lattice pattern with a fine pitch, facing each other at a predetermined angle. FIG.

Explanation of symbols

1 Lens holding part side scale member (movable side scale member)
2 Camera module body side scale member (fixed side scale member)
3, 3 ₁ , 3 ₂ abutting part 4 affixing surface 5 photointerrupter 5 ₁ light emitting element 5 ₂ light receiving element 10 lens holding part 11 lens 12 piezo element 12 ₁ actuating part 13 spring 14, 15 bearing part 20 camera module 21 Drive side shaft member 22 Guide shaft member 23 Camera module housing 24 Subject side lens 25 Base 26 Fixed lens holding portion 27 Substrate

Claims (7)

In a camera module having at least one optical lens and having a lens holding portion configured to be movable in the optical axis direction through the drive side shaft member and the guide shaft member.
A detection unit configured to detect an amount of movement of the lens holding unit in the optical axis direction, the detection unit being provided at a periphery of the lens holding unit, and a distance from the detection unit to the driving side shaft member from the detection unit; A camera module, which is provided at a position smaller than a distance to a guide shaft member and detects the amount of movement of the lens holding portion in the optical axis direction by moire fringes.   The detection unit includes a pair of moire fringe generating scale members disposed opposite to the lens holding unit side and the camera module main body side, and at least a part of the camera module main body side scale member housing portion around the lens holding unit side scale. The camera module according to claim 1, further comprising a scale member interval setting unit that protrudes toward a member and has a contact portion that contacts the lens holding portion side scale member. In a camera module having at least one optical lens and having a lens holding portion configured to be movable in the optical axis direction through the drive side shaft member and the guide shaft member.
A pair of moire fringe generating scale members disposed opposite to the lens holding unit side and the camera module main body side; and a distance setting means provided between the camera module main body side and the pair of moire fringe generating scale members. A camera module comprising: a detection unit that detects a movement amount of the lens holding unit in the optical axis direction by moire fringes.   The interval setting means between the pair of moire fringe generating scale members accommodates the camera module main body side scale member, and at least a part of the periphery protrudes by a set interval with the lens holding unit side scale member. The camera module according to claim 3, wherein the camera module includes a contact portion that contacts the holding portion side scale member.   The lens holding portion side scale member is formed of a flexible resin film, and is attached to the lens holding portion so as to come into contact with a contact portion provided on the camera module main body side. The camera module described in 2 or 4.   6. The camera module according to claim 1, wherein the lens holding portion is driven by a piezo element in which an operating portion is in contact with the driving side shaft member. A lens holding unit configured to be movable in the optical axis direction by inserting a driving side shaft member and a guide shaft member provided in the camera module body with at least one optical lens;
A detection unit that detects the amount of movement of the lens holding unit in the optical axis direction,
The detection unit includes a pair of moire fringe generation scale members provided on the periphery of the lens holding unit and arranged to face the lens holding unit side and the camera module main body side, and a moire pattern generated by the moire fringe generation scale member. It is configured with a fringe detection means, and a distance from the detection unit to the drive side shaft member is provided at a position smaller than a distance from the detection unit to the guide shaft member,
The camera module main body side scale member is provided with an abutting portion for projecting at a set interval from the lens holding portion side scale member so that the lens holding portion side scale member abuts at least a part around the housing portion. Contained in the containment unit,
The lens holding part-side scale member is formed of a flexible resin film, and is attached to the lens holding part so as to come into contact with the contact part provided on the camera module main body side.
An operation member, a display member, a battery, a communication unit,
A portable terminal comprising: the camera module, the display member, the battery, and a housing that houses the communication unit.

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