JP2009128500A - Actuator, imaging device, imaging apparatus, and method of manufacturing actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an actuator having excellent assemblability and drop impact resistance and reducing the size and thickness of a camera module. <P>SOLUTION: The actuator 101 comprises a holder 5b for directly or indirectly holding one or more lenses arranged along a fixed optical axis 6, a casing 8 for sliding the holder 5b along the optical axis 6 in the periphery of the holder 5b, and an energizing member 7 for pressing the holder 5b in one direction parallel to the optical axis 6. The energizing member 7 is fixed to the casing 8. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an actuator, an imaging device, an imaging device, and a method for manufacturing the actuator.

  An imaging device (hereinafter also referred to as a “camera module”) mounted on a mobile phone or a small device can handle a high number of pixels such as millions of pixels, or has a zooming mechanism for wide-angle or telephoto shooting. In order to improve the functions, a possible configuration and a configuration in which an autofocus mechanism is provided in order to improve the image quality are achieved. On the other hand, in order to cope with the downsizing and thinning of imaging devices including these camera modules, there is a demand for downsizing and thinning of camera modules. As a result, the size of the optical system and members constituting the camera module has to be reduced, and it has become difficult to assemble the members and assemble and adjust the optical systems.

  Therefore, it is required to make the configuration of the optical system and members simple, and to make the configuration and assembly thereof possible with as few steps as possible.

  The autofocus mechanism used in the camera module is a drive mechanism provided to move the optical system in the optical axis direction. For example, a magnet and a coil constitute a magnetic circuit, and the magnet ( There is a method of sliding a moving magnet) or a coil (moving coil), that is, a so-called voice coil system. In addition, there is a method of driving the optical system by frictional force generated when piezoelectric deformation is performed using a piezoelectric element or the like.

  Currently, a voice coil system is widely used in camera modules. An example of a document describing a voice coil system is, for example, Japanese Patent Application Laid-Open No. 2006-81387 (Patent Document 1).

In Patent Document 1, a voice coil drive mechanism is provided on the outer periphery of a lens assembly holding an optical system, and one end of a leaf spring is fixed to both ends of the lens assembly in the optical axis direction. The end is fixed to the drive mechanism. As a result, due to the thrust generated by the electromagnetic induction phenomenon, the plate spring fixed at both ends is deformed and the lens assembly moves in the optical axis direction.
JP 2006-81387 A

  Camera modules mounted on mobile phones and small devices are required to be small and thin. Along with this, the size required for optical systems and members has become smaller and it has become difficult to assemble parts and assemble and adjust optical systems.

  In the conventional camera module, the lens assembly is driven in the optical axis direction of the lens by deformation of the leaf springs fixed to both ends of the lens assembly. If the size of the member is reduced, the magnet and coil must be reduced, but in this case, the thrust generated by the electromagnetic induction phenomenon is also reduced. In order to be able to operate even with a small thrust, it is necessary to change the shape of the leaf spring in accordance with the obtained thrust. In that case, it is necessary not only to reduce the size of the leaf spring but also to reduce the thickness of the leaf spring. As the leaf spring becomes smaller and thinner, it becomes difficult to handle and assemble the leaf spring. In particular, it is difficult to fix the leaf spring to a yoke that is a part of the drive mechanism and to which a magnet is attached because the size is reduced as a whole.

  Furthermore, camera modules mounted on mobile phones and small devices are required to have drop impact resistance because they are carried by users. However, it is not possible to reduce the leaf spring size or reduce the thickness. Therefore, the risk of the leaf spring being deformed or damaged due to a drop impact is increased.

  The present invention is intended to solve the above-described problems. That is, an object of the present invention is to provide an actuator that is easy to assemble, has excellent drop impact resistance, and can realize downsizing and thinning of a camera module.

  In order to achieve the above object, an actuator according to the present invention includes a holder for directly or indirectly holding one or more lenses in a state of being arranged according to a certain optical axis, and the holder around the holder. A housing having a drive mechanism for sliding in the optical axis direction; and an urging member for pressing the holder in one direction parallel to the optical axis direction. It is fixed to the body.

  According to the present invention, parts can be easily handled and assembly work is facilitated. Moreover, it becomes possible to assemble with high accuracy.

(Embodiment 1)
(Constitution)
With reference to FIGS. 1-3, the actuator in Embodiment 1 based on this invention is demonstrated. An imaging device comprising an actuator according to the present invention is shown in FIG. The imaging device 201 includes an actuator 101 and a solid-state imaging unit 151. The actuator 101 is the actuator in the present embodiment.

  The actuator 101 includes a holder 5b for directly or indirectly holding one or more lenses 1, 2, 3 in a state of being arranged according to a certain optical axis 6, and the holder 5b around the holder 5b. A housing 8 having a drive mechanism for sliding in the direction and a biasing member 7 for pressing the holder 5b in one direction parallel to the direction of the optical axis 6 are provided. The biasing member 7 is fixed to the housing 8. FIG. 2 shows a state where only the actuator 101 is taken out of the imaging device 201 alone. FIG. 3 shows the actuator 101 where only the housing 8 is taken out. In FIG. 1, the portion of the housing 8 that should be visible behind the paper is not displayed, but in FIG. 3, the portion that is visible behind the paper is also displayed. In FIG. 2, a portion that is visible behind the page is simply indicated by a broken line.

  A combination of a lens barrel 5a having a threaded outer peripheral surface and a holder 5b having a threaded inner peripheral surface is referred to as a “lens assembly” 5. The lens barrel 5a holds the lenses 1, 2, and 3 inside. The lens barrel 5a is fixed to the holder 5b by being screwed inside the holder 5b. The screw between the lens barrel 5a and the holder 5b is for fine adjustment of the focal positions of the lenses 1, 2, and 3. A member such as the holder 5b may be generally called a “barrel”.

  In the present embodiment, the lens barrel 5a and the holder 5b are separate members and connected by screws, that is, the holder indirectly holds the lens. The target is not limited to such a configuration, and the holder may directly hold the lens.

  In the present embodiment, preferably, the urging member 7 is made of an elastic material, and the urging member 7 presses the lens barrel 5 in an elastically deformed state. The biasing member 7 may be made of metal, for example. The biasing member 7 is a leaf spring having a double circular structure. The urging member 7 includes an inner portion 7a and an outer portion 7b. The urging member 7 is connected to the urging member 7 as a whole by connecting with a bridge-like portion at several places. It is preferable that the urging member 7 is in contact with the lens barrel 5 at at least three locations. Here, the three places are, for example, three places that are 120 ° apart when viewed from above.

  As shown in FIGS. 1 and 2, a plurality of rotating bodies 9 are interposed between the lens assembly 5 and the housing 8. The rotating body 9 may be a ball, for example. The solid-state imaging unit 151 includes a solid-state imaging device (not shown). Since the actuator 101 in the present embodiment is combined with a solid-state imaging unit 151 including a solid-state imaging element, the lower end of the barrel 5 of the actuator 101 is in contact with the mounting surface of the solid-state imaging unit 151. It may be left.

  In the present embodiment, a rotating body is interposed between the lens assembly and the housing, but a structure without a rotating body may be used. However, if the holder is arranged in a biased manner with respect to the casing, the thrust changes depending on the size of the gap and causes tilting, so care must be taken not to bias it. If the structure using a rotating body is used as in the present embodiment, the holder of the lens assembly can be easily maintained in a state where the holder is evenly centered with respect to the inner peripheral shape of the housing, so that thrust can be obtained efficiently. And driving in the optical axis direction can be performed with high accuracy.

  FIG. 4 is a simplified view of an imaging apparatus (hereinafter also referred to as “camera module”) 201 equipped with the actuator 101 of the present invention. In FIG. 4, the displayed image pickup apparatus 201 is the same as that shown in FIG. 1, but each part of the image pickup apparatus 201 is simplified and displayed. With reference to FIGS. 1 and 4, each part of the imaging apparatus 201 will be described in detail.

(Solid-state imaging unit)
As already described, the solid-state imaging unit 151 includes a solid-state imaging device (not shown). As the solid-state imaging device, either a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor can be employed according to the required number of pixels. The solid-state imaging unit 151 is configured by mounting a solid-state imaging device constituted by these known techniques on a substrate or the like and sealing a region through which light passes at a position facing the solid-state imaging device with glass. ing. In the present embodiment, as shown in FIG. 1, the solid-state imaging device is mounted on a substrate, and the glass sealing portion 15 covers the upper surface of the solid-state imaging device. The peripheral portion 11 is sealed with resin or the like. In the glass sealing part 15, you may form or arrange | position an IR cut filter etc. as needed.

〔Optical system〕
An imaging device (camera module) is mounted on an imaging device such as a mobile phone or a digital still camera. The sizes of the optical system and the solid-state imaging unit in the imaging device are limited by the size of these imaging devices. In addition, with respect to the solid-state imaging device provided in the solid-state imaging unit, the optical system optimizes the shape and arrangement of the lens according to the optical design so that the optical performance can be best exhibited.

〔lens〕
As already described, the lens barrel is held by the holder which is a part of the actuator. One lens or a plurality of lenses may be held by the lens barrel. The same applies when the holder directly holds the lens. The present invention can be applied to any number of lenses. The lens is made of a transparent material such as glass or plastic. The lens is processed into a desired lens shape by cutting or molding using a mold. Usually, the lens is a combination of a plurality of lenses. The shape of the lens is optimized by the optical design of the optical system using a plurality of lenses, and a glass material or a resin material corresponding to the required transparency and refractive index is selected and formed as a spherical lens or an aspheric lens. An edge is further formed on each lens as necessary. The “edge” is a surface provided on the outer peripheral portion for fixing the lens to the lens barrel, and is an outer peripheral surface that is not involved in light entering / exiting in the assumed optical system and may be in contact with other members. It is.

  In order to meet the demands for downsizing, thinning, and increasing the number of pixels of a camera module, a plastic lens in which a lens material is made of plastic and an aspheric shape is formed by molding may be used. Plastic lenses are suitable for forming small shapes and complex aspheric shapes, and can be produced by molding using a mold, so they are suitable for producing many similar lenses. . In the case where a plastic lens is employed, it is easy to mass-produce camera modules having the same optical performance in this way.

  Furthermore, in recent years, assembly adjustment has become difficult due to the miniaturization of camera modules. However, if the lens can be fitted with an edge provided outside the effective diameter of the lens, the lens need not be adjusted. Assembling adjustment of the lens can be easily performed by fitting the edge between the lenses.

  Further, in order to prevent unnecessary light due to part of the light beam passing through the optical system or light that has passed outside the effective diameter of the lens, a light shielding member may be provided in the space between the lenses. In the case where a stop is provided in the optical system, any one of the light shielding members may function as a stop, or a configuration in which a stop function is provided to a part of the lens barrel may be employed. As a result of optical design of the optical system, it may be appropriately configured depending on the position of the stop.

  Optimizing the position of the stop of the optical system so that a part of the lens barrel has the function of the stop is preferable because it is not necessary to provide a new stop and the number of parts can be reduced by eliminating the need for a light shielding member. Furthermore, adjustment work is also unnecessary for aligning the optical axis between the aperture and the center of the lens, which is preferable because it can be assembled with high accuracy.

[Tube]
An optical system including one or more lenses is attached to a lens barrel and adjusted. The lens is fixed to the lens barrel with an adhesive or the like.

  The lens barrel is usually made of black plastic. The lens barrel is formed by processing such as molding or cutting using a resin such as ABS (Acrylonitrile Butadiene Styrene) resin, polycarbonate, or liquid crystal polymer. The type of resin material used at this time must be selected according to the application of the camera module on which the lens barrel is mounted. For example, when a lens barrel is used for a camera module mounted on a portable terminal or the like, the camera module is required to be small and thin. Accordingly, it is necessary to reduce the thickness of the wall surface constituting the lens barrel. However, it is also required to have high rigidity so that the shape is not deformed or damaged by an impact at the time of dropping. Therefore, it is desirable to select a resin material that can exhibit high rigidity even if the wall surface is thin. In addition, by performing impact analysis in advance, the location where deformation tends to be large or the location where damage is likely to occur is identified, and the thickness is locally increased or ribs are added at that location, which may cause deformation or damage. It is preferable to take measures by designing a strong shape.

(Drive mechanism)
As a drive mechanism for sliding a lens assembly as an optical system of the camera module along the optical axis, several methods can be adopted. For example, by using a stepping motor to slide the lens assembly in the optical axis direction along the cam or shaft axis (hereinafter referred to as “stepping motor method”), electromagnetic induction phenomenon generated by a magnet and a coil A method in which the lens assembly is slid in the optical axis direction by the generated thrust (hereinafter referred to as “VCM method”), and a method in which the lens assembly is slid in the optical axis direction by frictional force generated by a piezoelectric element or the like (hereinafter referred to as “VCM method”). , "Friction drive system").

  The driving mechanism may be selected as appropriate depending on the size of the camera module and the range in which the optical system is slid. For example, as a camera module having an autofocus function, the VCM method is often used as described in JP-A-2006-81387. The VCM method has been widely used since conventional camera modules have a size that allows easy handling of members and easy assembly.

[VCM method]
Next, the drive mechanism using the VCM method will be described in more detail. The drive mechanism based on the VCM system includes a magnet and a coil, and slides the lens barrel in the optical axis direction by a thrust generated by an electromagnetic induction phenomenon.

  The lens assembly that holds the lens barrel is disposed inside the housing, and the lens assembly and the housing are separated. One of the magnet and the coil is arranged so as to surround the outer periphery of the lens barrel in the lens assembly, and the other is provided in the housing. The frame of the housing may be made of a resin material, for example, when it is necessary to reduce the weight. For example, when the coil is arranged on the inner peripheral surface of the housing, the lens assembly having a magnet on the outer peripheral surface slides in the optical axis direction. This method is also called a “moving magnet”. Conversely, if the magnet is arranged on the inner peripheral surface of the housing, the lens assembly having a coil on the outer peripheral surface slides in the optical axis direction. This method is also called a “moving coil”. In applying the present invention, either a moving magnet or a moving coil may be used.

  As the camera module is reduced in size and thickness, the built-in magnet and coil are required to be reduced in size, and as a result of the reduction in size, the thrust is reduced as compared with the conventional case. Therefore, the lens assembly including the lens barrel is preferably as light as possible. The coil may be appropriately selected in consideration of the weight generated by the number of turns and the magnet by the weight generated by the processing size.

  If magnets and coils are arranged on the housing side instead of the lens assembly side, the magnets and coils may be fixed to the frame of the housing. However, in small devices, the leakage magnetic field becomes a problem as electromagnetic noise. There is a possibility. Therefore, it is preferable that a part of the frame is formed of a magnetic material (also referred to as “yoke”) so as to surround an outer periphery of a magnet or a coil disposed as a drive mechanism. For example, a configuration may be adopted in which a coil is arranged on the outer periphery of the holder of the lens assembly and a magnet is fixed to the yoke on the outer casing side with a gap (hereinafter referred to as “open magnetic circuit”). . With this configuration, it is possible to reduce the leakage magnetic field and to suppress the reduction of the magnetic field that contributes to the electromagnetic induction phenomenon, so that the thrust can be obtained more efficiently. Further, the yoke may have a configuration in which the cross-sectional shape of the yoke surrounds the magnet or the coil in a U-shape (hereinafter referred to as “closed magnetic circuit”), and in this way, the thrust can be obtained more efficiently.

  A drive mechanism may be manufactured by selecting an appropriate method according to the size required for the camera module and the thrust required for the drive mechanism.

(Friction drive system)
Next, an example of a drive mechanism using a friction drive system will be described below. A friction drive type drive mechanism is configured using a piezoelectric element or the like. A piezoelectric element is an element that causes deformation by applying a voltage. A piezoelectric element or the like is arranged so that deformation occurs in the optical axis direction. A shaft axis is arranged in a direction parallel to the optical axis, and one end of the shaft axis is fixed to the piezoelectric element. Further, a guide hole is provided at a position corresponding to the shaft axis among the members covering the outer periphery of the lens barrel. The depth direction of the guide hole is parallel to the optical axis direction. The end of the shaft shaft that is not fixed to the piezoelectric element is inserted into the guide hole. At this time, the shaft shaft and the guide hole are fitted so that a frictional force is generated between them.

  When the piezoelectric element or the like is deformed, the shaft axis is displaced along the optical axis direction. The lens assembly having the guide hole slides along the optical axis direction by the frictional force generated thereby. At this time, if a difference in speed is provided depending on the direction of displacement, the lens assembly can be moved forward or backward. That is, for example, the lens assembly can be advanced by extending the piezoelectric element at high speed and contracting at low speed. In that case, the lens assembly can be retracted by extending the piezoelectric element at low speed and contracting at high speed.

[Stepping motor system]
Next, a drive mechanism using a stepping motor system will be described below. In this type of drive mechanism, the gear provided on the stepping motor and the gear provided on the shaft are engaged. By operating the stepping motor, the shaft axis rotates by a desired angle. The outer peripheral surface of the lens barrel is threaded, and the lens barrel slides in the optical axis direction corresponding to the rotation angle of the shaft axis. At this time, in order to slide the lens barrel in the optical axis direction, it is necessary to separately provide a guide shaft. If it does in this way, it can be made to slide along a guide axis.

  In applying the present invention to an actuator or an imaging device, the actuator may be configured using any type of drive mechanism. An optimal drive mechanism method may be selected in consideration of the downsizing and thinning of the camera module and the accompanying reduction in the component size.

[Biasing member of the present invention]
As described above, the camera module is an optical system including a solid-state image pickup unit on which a solid-state image sensor is mounted and one or more lenses provided on the central axis of the solid-state image sensor to guide light rays to the solid-state image sensor. And a drive mechanism for sliding the optical system of the lens barrel in the optical axis direction of the lens.

  In the actuator, in order to stably slide the barrel in the optical axis direction, a member that defines the relative positional relationship between the barrel and the casing is provided between the barrel and the casing. . In the example shown in FIG. 1, a rotating body 9 is arranged as a member that defines the relative positional relationship.

(Action / Effect)
In the actuator according to the present embodiment, it is easy to handle parts and to perform assembly work. Moreover, it is excellent in drop impact resistance, and the camera module can be made smaller and thinner. Moreover, it becomes possible to assemble with high accuracy. These will be described in detail below.

  For example, in the VCM system described in Patent Document 1, leaf springs are provided at both ends in the optical axis direction of the lens barrel, the leaf springs at the upper end of the lens barrel are fixed to the yoke constituting the closed magnetic circuit, and the lower ends are By fixing to the frame, the lens barrel is slid stably in the optical axis direction.

  As described so far, the size of parts has been reduced by the miniaturization and thinning of the camera module. In particular, leaf springs are required not only to be reduced in size but also to be thinner. This is to cope with a reduction in thrust due to a reduction in the size of the magnet and coil constituting the magnetic circuit. In order to be able to move the lens barrel even with a small thrust, the leaf spring needs to be small and thin. In this way, since the size of the leaf spring is reduced and the thickness is also reduced, it is difficult to fix the lens barrel via the leaf spring.

  Furthermore, the downsizing and thinning of the camera module is due to the downsizing of imaging equipment such as a mobile phone equipped with the camera module, which is because it is required to be portable. Since small portable imaging devices are often subjected to a drop impact, camera modules mounted on these imaging devices are particularly damaged due to deformation of a leaf spring.

  Therefore, as shown in FIG. 4, one end of the biasing member 7 is fixed to the outer casing 8 using a leaf spring as the biasing member 7, and the other end of the biasing member 7 is connected to the lens assembly 5. It was set as the structure made to contact | abut. By adopting this configuration, the end of the urging member 7 presses the lens assembly 5, and the lens assembly 5 can be restricted from sliding freely, so that the influence of a drop impact is suppressed. be able to. Further, by improving the positional accuracy of the contact between the urging member 7 and the lens assembly 5, the positional accuracy of the lens assembly 5, that is, the positional accuracy of the lens barrel 5a can be easily secured, and the light Tilt in sliding in the axial direction can also be suppressed.

  Further, in the configuration shown in FIG. 4, the initial state of the lens assembly 5 can be determined by pressing the lens assembly 5 in one direction by the urging member 7, so that the lens assembly 5 holds the lens assembly 5. Further, the distance in the optical axis direction between one or a plurality of lenses provided in the lens barrel 5a and the solid-state imaging device can be maintained at a desired value, and stable optical performance can be obtained.

(Embodiment 2)
(Constitution)
With reference to FIG. 5, the actuator in Embodiment 2 based on this invention is demonstrated. The actuator 102 in the present embodiment includes a fixing member 10 that is fixed to the housing 8, and the biasing member 7 is fixed to the fixing member 10.

  In the actuator 102 in the present embodiment, the urging member 7 presses one end, that is, the upper end 5u along the optical axis direction of the holder 5b. The housing 8 is in contact with the other end, that is, the lower end 5v along the optical axis 6 of the holder 5b, and stops so that the holder 5b does not move due to pressing by the biasing member 7. 14 is provided.

  The contact portion 14 may be formed so as to be integrated with a resin portion forming a part of the housing 8 or may be formed as a separate part. In the example shown in FIG. 1, the contact portion 14 is formed of a metal member. The contact portion may be formed of resin or metal.

(Action / Effect)
It is preferable that the urging member is fixed to the fixing member like the actuator 102 in the present embodiment because the urging member can be easily handled. In particular, in the present embodiment, since the housing 8 includes the contact portion 14, it is easy to assemble the actuator, which is preferable. When assembling the camera module, when the holder and the housing are combined first, and then the solid-state imaging unit is attached, as shown in the present embodiment, a contact portion for receiving the holder is provided on the housing. This is because the holder and the housing can be assembled and stabilized first.

  In such a configuration in which the contact portion for receiving the holder is provided near the lower end of the housing, the distance between the surface of the solid-state imaging device and the holder is designed in consideration of the thickness of the contact portion. Just keep it. If the thickness of the contact portion is changed as necessary, the distance between the surface of the solid-state imaging device and the holder can be set to a desired value, so that the lens is accurately attached to the holder. As long as it is present, the camera module can be assembled without adjusting the interval after assembly.

  In general, as the camera module becomes smaller and thinner, the size of the members constituting the camera module becomes smaller, and the handling thereof becomes more difficult. In particular, regardless of the type of the drive mechanism, the components constituting the drive mechanism are also reduced by downsizing and thinning, so the thrust and frictional force by which the drive mechanism displaces the lens assembly is reduced. Therefore, in order to be able to move even with a small force generated by the drive mechanism, it is desirable that the biasing member be flexible. Accordingly, measures are taken not only to reduce the size of the elastic member that constitutes the urging member, but also to reduce the thickness or narrow the elastic region. As a result, handling of the biasing member has become increasingly difficult.

  In the actuator 102 in the present embodiment, the fixing member 10 is insert-molded so as to take in a part of the biasing member 7. Although other methods may be used for fixing the urging member 7 to the fixing member 10, it is preferable that the urging member is easily formed by insert molding as described above. This configuration not only facilitates handling but also facilitates assembly. Furthermore, since the positional accuracy with the fixing member can be ensured by insert molding, the stability of the lens barrel can also be obtained.

  In the example shown in FIG. 1, the contact portion 14 has a configuration that also serves to prevent the rotating body 9 from popping out.

  Note that the contact portion may be configured to be used as a member for adjusting the positional relationship of the lens with respect to the solid-state imaging measure. By adopting this configuration, it is possible to eliminate the need for a screw that has conventionally been required to be provided between the lens barrel and the holder in order to adjust the focal position of the lens barrel that holds the lens. Therefore, the camera module can be further reduced in size.

(Embodiment 3)
(Production method)
With reference to FIGS. 6-8, the manufacturing method of the actuator in Embodiment 3 based on this invention is demonstrated.

  FIG. 6 is an exploded view of components used. Here, the casing 8, the holder 5b for holding the lens barrel holding a plurality of lenses (not shown), the biasing member 7 for pressing the holder 5b, and the biasing member are fixed. A fixing member 16 is displayed. The housing 8 includes a contact portion 14 at the lower end. The housing 8 has a cylindrical shape, and the inner space is a holder storage area 17.

  In the manufacturing method of the actuator in the present embodiment, the holder 5b for directly or indirectly holding one or more lenses arranged in accordance with a certain optical axis is slid in the optical axis direction. The fixing member 16 is used to fix the biasing member 7 for pressing the holder 5b in one direction parallel to the optical axis direction. And fixing to 8. That is, as shown in FIG. 7, the holder 5b is mounted in the holder storage area 17 inside the housing 8 from a disjoint state as shown in FIG. Actually, it is practical to mount the holder 5b in which the lens barrel 5a holding the lens is fixed, that is, the lens assembly, instead of the empty holder 5b. At this time, the space between the holder 5b and the housing 8 is such that the optical axis 6 and the center line of the housing 8 by one or a plurality of lenses held directly or indirectly by the holder 5b coincide with each other. In addition, a member for forcibly forming gaps at equal intervals may be disposed. For example, if a plurality of spherical bodies having a uniform diameter are arranged in the gap between the holder 5b and the housing 8, gaps at equal intervals can be formed. It is good also as arrange | positioning some rotary bodies which are not restricted to a spherical body. By disposing the rotating body 9 as shown in FIG. 1 in the gap around the lens assembly 5, it is possible to provide an actuator with further improved drop impact resistance.

  Further, as shown in FIG. 8, the urging member 7 that presses the holder 5b is placed so as to cover the holder 5b across the housing 8, and is placed on the outer end of the urging member 7, that is, the housing 8. The fixed end is fixed by the fixing member 16. In order to fix the fixing member 16 to the housing 8, an adhesive or the like may be used. The biasing member 7 may ensure the positional accuracy by the outer peripheral portion of the housing 8 or the positioning structure provided in the housing 8 as appropriate. Alternatively, a positioning structure may be provided on the fixed member 16 side to ensure positional accuracy. In any case, the urging member 7 comes into contact with the end portion of the holder 5b, and the urging member 7 presses and supports the holder 5b, whereby the central axis of the housing 8 and the holder 5b are held. The optical axis 6 of one or more lenses can be made coincident. Thus, the actuator 103 is obtained as shown in FIG.

(Action / Effect)
The manufacturing method of the actuator in the present embodiment as described above can be applied regardless of the type of the drive mechanism, and can be assembled to the structure shown in FIG. 8 by the same process. Therefore, the positional accuracy of the lens barrel can be ensured with a simple configuration and a simple assembly method.

(Embodiment 4)
(Constitution)
With reference to FIG. 9, the actuator in Embodiment 4 based on this invention is demonstrated. In the actuator 104 according to the present embodiment, the urging member 7 has an urging member inclined surface 7c that is an inclined surface with respect to the optical axis direction, and the urging member inclined surface 7c is an end of the holder 5b. Abut.

(Action / Effect)
In the present embodiment, the corner of the end of the holder 5b can be brought into contact with the biasing member, so that the holder 5b is prevented from being undesirably displaced in the direction of the optical axis 6 and the position of the holder 5b is stabilized. It is possible. Thereby, the drop impact resistance can also be improved.

(Modification)
Further, a modification of the present embodiment is shown in FIG. The place where the holder 5b used in this modification is taken out alone is shown in FIG. In this example, the holder end inclined surface 5c is also provided on the holder 5b side so as to come into surface contact with the inclined biasing member inclined surface 7c. In the actuator 105 of this modification, the holder 5b has a holder end inclined surface 5c that is a surface inclined with respect to the optical axis direction at the end, and as shown in FIG. 10, the biasing member inclined surface 7c. Is in contact with the holder end inclined surface 5c. With such a configuration, not only can the same effect as the actuator 104 shown in FIG. 9 be obtained, but also the positional accuracy of the holder 5b in the direction along the plane perpendicular to the optical axis 6 can be ensured. Is possible. Thereby, the drop impact resistance can also be improved.

  The holder end inclined surface 5c may be formed by cutting out the material constituting the holder 5b. If the holder 5b is manufactured by molding, a shape portion corresponding to the holder end inclined surface 5c may be provided in the mold of the holder 5b.

  On the other hand, the urging member inclined surface 7c provided on the urging member 7 can also be easily produced by deforming the elastic member. As described above, in the present embodiment and its modification, an actuator that does not require a complicated structure and can be easily assembled can be obtained.

  In the modification of the present embodiment, an inclined surface is provided at the end of the holder, but a groove may be provided instead of the inclined surface. In that case, for example, as shown in FIG. 12, a groove 18 concentric with the outer shape of the holder 5 b is formed on the upper surface of the holder 5 b, and the inner end of the biasing member 7 is in contact with the groove 18. . A bent portion 7 d is provided at the inner end portion of the urging member 7 so that the bent portion 7 d enters the groove 18. Even with this configuration, it is possible to obtain the same effect as the example described first in the present embodiment.

(Embodiment 5)
(Constitution)
With reference to FIGS. 13 and 14, an actuator according to a fifth embodiment of the present invention will be described. In the actuator 106 in the present embodiment, the biasing member 7 is insert-molded so as to be partially taken into the end of the holder 5b. In the example shown in FIG. 13, the end of the holder 5b in which one end of the biasing member 7 is insert-molded is an upper end 5u. The other end, that is, the outer end of the urging member 7 is fixed to the upper portion of the housing 8 by a fixing member 16.

(Action / Effect)
In the present embodiment, since the biasing member 7 is insert-molded so as to be integrated with the holder 5b, the handling of the biasing member 7 is facilitated during assembly, which is preferable. If this configuration is adopted, handling is easy, and assembly work is also facilitated. Thereby, the drop impact resistance can also be improved.

  In each of the above embodiments, the configuration of the drive mechanism has not been described in detail. However, in the actuator of each embodiment, the drive mechanism may be any of the systems exemplified below.

  As a first example, the drive mechanism may be a VCM system. That is, the drive mechanism may be for sliding the lens barrel 5 in the optical axis direction by an electromagnetic induction phenomenon caused by a magnet and a coil. For example, the configuration is like an actuator 107 provided in the imaging apparatus 202 shown in FIG. In this actuator 107, the drive mechanism includes a yoke 31, a coil 32, and a magnet 33. The yoke 31 is a part of the housing 8. FIG. 14 shows an example in which the coil 32 is disposed on the outer peripheral surface of the holder 5b and the magnet 33 is disposed on the inner peripheral surface of the yoke 31, but conversely, the magnet is disposed on the outer peripheral surface of the holder 5b. The structure arrange | positioned at the inner peripheral surface of the yoke 31 may be sufficient. If it is the structure of such a 1st example, it can be set as the structure which has arrange | positioned the coil and the magnet equally to the outer peripheral part of a holder. Since the thrust is evenly generated by the interaction between the coils and the magnets arranged uniformly in this way, it is preferable because a stable actuator can be obtained. In that case, the pressing by the urging member only needs to be made uniform, which is convenient and easy to design.

  As a second example, the drive mechanism may be a friction drive system. That is, the drive mechanism may be for sliding the holder 5b in the optical axis direction by frictional force by displacing the piezoelectric element around the holder 5b. With the configuration of the second example as described above, the drive mechanism using at least one piezoelectric element has only to be arranged around the holder 5b, so that there is little space available for constructing the drive mechanism. But it is easy to realize. As a result, it is preferable for further downsizing the camera module.

(Imaging device)
As mentioned above, in each embodiment, the structure of the actuator based on this invention has been demonstrated. These actuators are combined with the solid-state imaging unit 151 to form a camera module, that is, an imaging device. Therefore, an imaging apparatus according to the present invention includes any one of the actuators described above and a solid-state imaging unit 151 on which a solid-state imaging element is mounted. For example, the imaging apparatus 201 shown in FIG. With such an imaging apparatus, it is easy to assemble the actuator portion. In addition, the imaging device is excellent in drop impact resistance and highly reliable.

(Imaging equipment)
The imaging device based on this invention is provided with the above-mentioned imaging device. The “imaging device” is, for example, a mobile phone or a digital still camera. An example is conceptually shown in FIG. As shown in this figure, a mobile phone 301 as an imaging device is equipped with an imaging device 201. Similar effects can be obtained in such an imaging device. Particularly, in an imaging device in a field where downsizing and emphasis on portability are important, since drop impact resistance is required, it is advantageous to mount the imaging device according to the present invention.

  In addition, the said embodiment disclosed this time is an illustration in all the points, Comprising: It is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and includes all modifications within the scope and meaning equivalent to the terms of the claims.

It is sectional drawing of the imaging device in Embodiment 1 based on this invention. It is sectional drawing of the actuator with which the imaging device in Embodiment 1 based on this invention is provided. It is sectional drawing of the housing | casing with which the actuator in Embodiment 1 based on this invention is provided. It is a schematic sectional drawing of the imaging device in Embodiment 1 based on this invention. It is a schematic sectional drawing of the actuator in Embodiment 2 based on this invention. It is 1st explanatory drawing of the manufacturing method of the actuator in Embodiment 3 based on this invention. It is 2nd explanatory drawing of the manufacturing method of the actuator in Embodiment 3 based on this invention. It is 3rd explanatory drawing of the manufacturing method of the actuator in Embodiment 3 based on this invention. It is a schematic sectional drawing of the actuator in Embodiment 4 based on this invention. It is a schematic sectional drawing of the modification of the actuator in Embodiment 4 based on this invention. It is a schematic sectional drawing of the lens barrel with which the modification of the actuator in Embodiment 4 based on this invention is equipped. It is a partial schematic sectional drawing of the further modification of the actuator in Embodiment 4 based on this invention. It is a schematic sectional drawing of the actuator in Embodiment 5 based on this invention. It is sectional drawing in case the actuator in Embodiment 5 based on this invention is a VCM system. It is a conceptual diagram of the imaging device based on this invention.

Explanation of symbols

  1, 2, 3 Lens, 5 Lens assembly, 5a Lens barrel, 5b Holder, 5c Holder end inclined surface, 5u Upper end of holder, 5v Lower end of holder, 6 Optical axis, 7 Energizing member 7a inner part, 7b outer part, 7c biasing member inclined surface, 7d bent part, 8 housing, 9 rotating body, 10, 16 fixing member, 11 peripheral part, 14 contact part, 15 glass sealing part, 17 Holder storage area, 18 groove, 31 yoke, 32 coil, 33 magnet, 101, 102, 103, 104, 105, 106 actuator, 151 solid-state imaging unit, 201 imaging device, 301 mobile phone.

Claims (13)

A holder for directly or indirectly holding one or more lenses in a state of being arranged according to a certain optical axis;
A housing having a drive mechanism for sliding the holder in the optical axis direction around the holder;
An urging member for pressing the holder in one direction parallel to the optical axis direction;
The urging member is an actuator fixed to the casing.   The actuator according to claim 1, wherein the biasing member is made of an elastic material, and the biasing member presses the holder in a state of being elastically deformed.   The actuator according to claim 1, wherein the urging member is in contact with the holder at at least three locations.   The actuator according to claim 1, further comprising a fixing member fixed to the housing, wherein the biasing member is fixed to the fixing member.   The actuator according to claim 4, wherein the fixing member is insert-molded so as to capture a part of the biasing member.   The biasing member has a biasing member inclined surface that is a surface inclined with respect to the optical axis direction, and the biasing member inclined surface is in contact with an end of the holder. The actuator according to any one of the above.   The holder has, at its end, a holder end inclined surface that is an inclined surface with respect to the optical axis direction, and the biasing member inclined surface is in contact with the holder end inclined surface. Actuator.   The actuator according to claim 1, wherein the biasing member is insert-molded so as to be partially taken into an end portion of the holder. The biasing member presses one end of the holder along the optical axis direction,
The housing includes an abutting portion that abuts against the other end portion of the holder along the optical axis and prevents the holder from being moved by pressing by the urging member. The actuator according to any one of claims 1 to 8.   The actuator according to any one of claims 1 to 9, wherein the driving mechanism is for sliding the holder in the optical axis direction by an electromagnetic induction phenomenon caused by a magnet and a coil. The actuator according to any one of claims 1 to 10,
One or more lenses held in the holder of the actuator;
An imaging apparatus comprising: a solid-state imaging unit on which a solid-state imaging element is mounted.   An imaging device comprising the imaging device according to claim 11. A holder for directly or indirectly holding one or more lenses in a state of being arranged according to a certain optical axis is provided in a holder storage area provided inside a housing for sliding the holder in the optical axis direction. Arranging, and
And a step of fixing an urging member for pressing the holder in one direction parallel to the optical axis direction to the housing by a fixing member.

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