JP2007047457A - Camera module and information terminal with camera module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera module constituted to be small in size and light in weight and coping with shavings caused by the frictional abutting of an electrostrictive element on a driven member, and an information terminal with the camera module. <P>SOLUTION: The camera module 1 is equipped with: the electrostrictive element 8; a drive shaft 9 whose one end side in a shaft direction is coupled with the electrostrictive element 8 and which reciprocates or contracts/elongates in the shaft direction by voltage applied to the electrostrictive element; and a lens holding part 2 with which a sliding member 5 frictionally engaged with at least part of the peripheral surface of the drive shaft 9 is coupled. A dust collecting member 10 is disposed near the sliding member 5, desirably, a gap is provided on the side of the sliding member 5 facing to the drive shaft 9, and the dust collecting member 10 is disposed in the gap so as to abut on the drive shaft 9. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a small and lightweight camera module used for an information terminal and the like and an information terminal equipped with the camera module.

  Camera modules used for information terminals such as recent mobile phones are equipped with high-speed, high-precision autofocus (AF) functions similar to those of ordinary electronic cameras (digital cameras) as the number of pixels of the image sensor (CCD) increases. And a focal length change (zoom) function are required, and further downsizing and weight reduction of the information terminal itself inevitably requires downsizing and weight reduction of the camera module.

  In order to perform autofocus and change in focal length (zoom) in such a camera module, it is necessary to move the lens group in the direction of the optical axis. As shown in the figure, one cylindrical cam arranged on the side surface of the optical system is driven by a motor to drive the zoom lens frame and the AF lens frame, and the cylindrical cam is also arranged adjacent to the lens frame. Is driven by a motor, thereby moving the lens frame for autofocus and the zoom lens frame to switch between two points of tele and macro.

  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.

  However, in conventional camera modules using such cylindrical cams, lead screws, helicoids, etc., electromagnetic motors or pulse motors having a rotor are generally used as the drive source. The electromagnetic motor that uses the rotor requires an electromagnet or permanent magnet around it, and even if the axial length is shortened, the cylindrical part is indispensable. In addition, noise is also generated.

  Therefore, in order to solve the disadvantages of such an electromagnetic motor, a piezo element (PZT) that generates mechanical distortion in response to changes in electric and magnetic fields has been conventionally used as a drive source for moving the lens frame in the optical axis direction. Friction drive type drive source, so-called electrostrictive element, is used, in which a mechanical vibrator is composed of a piezoelectric element such as a rotor and a slider is brought into contact with the mechanical vibrator so that the vibration of the mechanical vibrator can be extracted as an output. ing. Such a friction drive type drive source is low speed but has 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.

  For example, Patent Document 2 discloses an optical device in which a piezoelectric element is arranged on a lens frame and drives the lens like a scale insect, and Patent Document 3 discloses a linear drive vibration wave actuator (electrostrictive element). And a lens frame that directly drives a lens frame by contact of an electrostrictive element has been proposed.

  Furthermore, a linear actuator that moves the slider in an arbitrary direction by frictionally engaging the slider with the drive shaft that reciprocates or expands and contracts and movably moves along the drive shaft, and drives the drive shaft asymmetrically in the front-rear direction. In such a linear actuator, it is necessary for stable operation that the slider can move smoothly with a predetermined frictional force on the drive shaft in a non-driven state.

  However, in a linear actuator using such an electrostrictive element or a friction drive type drive source, depending on a long-term use or usage environment, a contact portion between the drive unit and the driven unit is scraped by friction, and the scraped scraps may be generated. The lens may be stained as dust, resulting in ghosts and flares, etc., and corrosive substances generated by corrosive gas and oxidizing gas such as hydrogen sulfide, NOx, and ozone, and deposits such as dust and wear may accumulate. is there. In addition, depending on the drive shaft and slider material even under high temperature and high humidity environment, the composition component may be separated and adhered to the surface of the material, contaminating the friction engagement part between the slider and the drive shaft. The slider may not move smoothly.

  As a method for dealing with such dust inside the optical system, for example, in Patent Document 4, an adhesive is applied to the inside of the optical system to catch dust scattered by the rotation of the polygon mirror, or an opening around the optical path is formed with an adhesive tape. It is shown to block and adsorb dust. In Patent Documents 5 and 6, wear dust generated by friction using an electrostatic adsorbent material outside the optical axis region, or by using a resin material for the rotary polyhedral mirror bearing, is obtained by friction charging. A structure that is attached to a bearing portion is disclosed.

JP 7-63970 A Japanese Patent Laid-Open No. 5-107440 JP-A-7-104166 JP-A-6-148550 JP 9-294193 A JP-A-9-127451

  However, the technique disclosed in Patent Document 2 is a mechanism for driving a camera lens of a normal size, and camera modules used for information terminals such as mobile phones are always required to be downsized. Too big to apply to information terminals.

  Further, the techniques disclosed in Patent Documents 4 and 5 also adsorb dust floating in the optical system and scattered foreign matters and do not deal with scraps scraped by friction. Although it is a wear powder, it is only adsorbed by frictional electrification, so if it stops rotating, it may float as dust and cannot be a fundamental solution.

  Therefore, in the present invention, an autofocus (AF) function and a zoom function are incorporated by using a linear actuator using an electrostrictive element, and it is configured to be small and lightweight, and the electrostrictive element and the driven member are brought into frictional contact. It is an object to provide a camera module that copes with shavings and the like and an information terminal equipped with the camera module.

Therefore, in order to solve such a problem, the present invention has an electrostrictive element and one end side in the axial direction connected to the electrostrictive element, and a reciprocating motion or a telescopic motion in the axial direction by a voltage applied to the electrostrictive element. A camera module, and a lens holding part connected to a sliding member that frictionally engages at least a part of the peripheral surface of the drive shaft,
A dust collecting member is disposed in the vicinity of the sliding member.

According to the present invention, even when scraps generated by sliding between the drive shaft and the sliding member interlocked with the electrostrictive element, or deposits such as corrosive substances generated by corrosive gas or acidic gas, It is captured by the dust collecting member arranged in the vicinity of the sliding surface, and it is possible to prevent the lens from being stained as dust and ghosts and flares from being generated. Therefore, even when used for a long period of time, the frictional force between the drive shaft and the sliding member can be maintained stably and moderately, and malfunction of the linear actuator can be prevented. Furthermore, according to the present invention, a camera module having an autofocus (AF) function and a zoom function can be configured to be small and lightweight.
The vicinity of the sliding member may be any position as long as the sliding member is on the side facing the drive shaft, and includes a position facing the electrostrictive element.
In addition, a gap is provided in a direction perpendicular to the sliding direction of the sliding member facing the drive shaft, and the dust collecting member is disposed in the gap so as to contact the drive shaft. . By configuring in this way, space can be saved and the size can be reduced.
Further, the dust collecting member is disposed on an end portion of the sliding member on the electrostrictive element side and on a side facing the driving shaft or the circumferential surface of the electrostrictive element. Thus, by arranging the dust collecting member at the end portion on the electrostrictive element side, the generated scraps can be effectively collected. Furthermore, it is preferable to dispose a dust collecting member on the opposite end portion of the sliding member together with the electrostrictive element side, whereby a dust collecting member is provided at both ends of the sliding member in the drive axis direction, More effective dust collection is possible.
Further, the sliding member is frictionally engaged with the drive shaft at two locations. With this configuration, the sliding portions are dispersed, the concentration of pressing portions on the drive shaft can be avoided, the generation of scraps can be suppressed, and the optical axis of the lens can be made more stable.

Further, the gap between the sliding members is provided at least at two axial ends of the drive shaft, and the dust collecting members are respectively disposed in the gaps at the two locations.
By setting it as such a structure, deposits, such as shavings, can be removed effectively. In particular, by arranging the dust collecting members on the upper and lower end portions of the drive shaft where the scraps are likely to be generated, this can be supplemented before the scraps are scattered.
Furthermore, the surfaces of the sliding member and the dust collecting member that are in contact with the drive shaft are formed in a circular arc shape in cross section.
In this way, by forming the sliding member in a substantially semicircular shape having an arc cross section instead of an annular shape, the sliding member can be supported by urging from only one direction, and applied to the drive shaft. A contact property can be maintained high. In addition, the dust collecting member has an arcuate cross section like the sliding member, so that it is possible to reliably collect shavings generated on the sliding surface of the sliding member and the drive shaft, and the dust collecting performance is improved. improves.

Further, two or more gaps of the sliding member are provided in the axial direction of the drive shaft, and an adhesive member is disposed at at least one position of the gap.
As a result, it becomes possible to adhere and collect the shavings that cannot be collected by the dust collecting member with the adhesive member, and the dust collecting performance is further improved.
Furthermore, it is preferable to arrange an adhesive member between the two locations.
Thereby, this adhesive member can be arrange | positioned, without adding the arrangement | positioning space of an adhesive member.

  Further, the surface of the drive shaft that contacts the sliding member is processed to be rougher than the non-contact surface. Further, the drive shaft is supported by being sandwiched between the sliding member and a fixed frame disposed on the opposite side of the sliding member, and the friction coefficient on the sliding surface on the fixed frame side is It is characterized in that the treatment is made lower than the friction coefficient on the sliding surface on the sliding member side. Further, the drive shaft is supported by being sandwiched between the sliding member and a fixed frame disposed on the opposite side of the sliding member, and slides on the fixed frame of the drive shaft. A lubrication treatment is performed on the surface on the side, and the lubrication treatment is omitted on the surface on the side that slides on the sliding member. According to these inventions, the driving by the electrostrictive element can be performed more effectively, and the friction loss of the sliding surface can be reduced.

Further, an elastic member that biases the sliding member in a direction in which the sliding member comes into contact with the drive shaft is provided.
Thereby, it is possible to apply an ineffective force to the electrostrictive element with an appropriate force with a simple configuration.

A lens holding unit for holding at least one optical lens;
An electrostrictive element is connected to one end side in the axial direction, and a drive shaft that reciprocates or expands and contracts in the axial direction by a voltage applied to the electrostrictive element;
A sliding member connected to the lens holding portion and frictionally engaged with at least a part of a peripheral surface of the drive shaft;
A camera module comprising: at least one dust collecting member disposed in a gap provided in a direction perpendicular to the sliding direction on the side facing the drive shaft of the sliding member;
An operation member, a display member, a battery, a communication unit,
A housing that houses the camera module, the operation member, the display member, the battery, and the communication unit, and that regulates the thickness of the housing to a height of the camera module. We propose an information terminal characterized by
By using an information terminal incorporating such a camera module, a camera module having an autofocus (AF) function and a zoom function can be configured to be small and lightweight.

  As described above, according to the present invention, an autofocus (AF) function and a zoom function are incorporated using an electrostrictive element typified by a piezo element, and it is configured to be small and lightweight, and connected to the electrostrictive element. A camera module that has also dealt with scraps generated by frictional contact between the drive shaft and the sliding member connected to the lens holding part, and deposits such as corrosive substances caused by corrosive gas and acid gas. 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 a schematic cross-sectional view of a camera module of a driving portion in the present embodiment. FIG. 2 is a perspective view of the camera module of FIG. 1 viewed from the subject lens direction (A), and a perspective view viewed from the image sensor direction. FIG. 3 is a diagram for explaining the operation of the camera module according to the present embodiment. The state in which the lens is at the most telephoto (tele) side (a), the state at which the lens is at the widest (wide) side (b), and FIG. FIGS. 5A and 5B are diagrams showing a contact state between a moving member and a drive shaft, and are a side sectional view (a), a plan sectional view (b), a sectional view (c) of a main part, and FIG. The left side view (a), the top view (b), the right side view (c), the perspective view from the lower left (d), the perspective view from the upper right (e), the line AA in (b) Sectional view (f), BB sectional view (g) in (b), CC section in (b) (H), FIG. 6 is a perspective view (a) showing the entire configuration of the camera module of the present embodiment, a perspective view (b) when the cover is mounted, and FIG. 7 is a portable device incorporating the camera module of the present embodiment. It is a figure which shows an example of a telephone set schematically. In the figure, the same number is attached | subjected to the same component.

  First, with reference to FIG.1 and FIG.2, the main schematic structure of the camera module 1 which concerns on this embodiment is demonstrated. As shown in the figure, the camera module 1 of the present embodiment is connected to a lens holding frame 2 that holds an imaging lens, a drive shaft 9 that reciprocates or expands and contracts in the axial direction, and the lens holding frame 2. The sliding member 5 that frictionally engages at least a part of the drive shaft, the electrostrictive element 8 that is connected to the drive shaft 9 and positions the lens holding frame 2, and the drive shaft 9 is electrostrictive on the other end side. A stable weight member 3 connected to the element, a fixed frame 4 connected to the stable weight member 3 and restricting the movement of the drive shaft 9, a spring member 7 for biasing the sliding member 5 to the drive shaft 9, The spring receiver 6 that supports the spring member 7 is a main component.

A linear actuator that drives and controls the lens holding frame 2 includes a stable weight member 3, an electrostrictive element 8, and a drive shaft 9. The stable weight member 3 absorbs repulsion due to vibration, and thus does not increase in weight, and has high flexibility (natural frequency) in order to minimize the influence on the camera module component and the influence from the camera module component. (Low) of the joining member. The electrostrictive element 3 is an element that is extended and driven in a direction parallel to the optical axis by applying a voltage in a stacked type, and is represented by a piezo element. The drive shaft 9 is joined to the electrostrictive element 8 by pressing or fixing with a bonding agent, and is driven to expand and contract in a direction parallel to the optical axis in conjunction with the electrostrictive element 8. The drive shaft 9 is sandwiched between the sliding surface 4 a of the fixed frame 4 and the sliding surface 5 a of the sliding member 5 connected to the lens frame holding portion 2, and the sliding member 5 and the spring receiver 6. Between them, a spring member 7 for pressing the sliding surface is arranged. In addition, as a spring member, elastic members, such as a leaf | plate spring which does not exceed a yield point, a plastic spring, and a viscous polymer material other than a spring, can be used. That is, the sliding member 5 is pressed against and supported by the drive shaft 9 by the spring member 7.
Further, the load of the spring member 7 is sufficiently smaller than the friction between the drive shaft 9 and the sliding member 5, but is sufficient to stabilize the optical axis of the lens.

The driving mechanism of the lens holding frame 2 in the present embodiment enables a small and high-accuracy driving by utilizing the steep volume change of the electrostrictive element 8 and the inertia and frictional force of the driving shaft 9 that is a moving body. This makes it possible to precisely position the lens.
The driving principle of the lens moving operation by the electrostrictive element is as follows.
When the electrostrictive element 8 extends rapidly, the drive shaft 9 connected to the electrostrictive element 8 rapidly moves simultaneously, and the sliding member connected to the peripheral surface of the drive shaft 9 and the lens holding frame 2. The sliding surface 5a of 5 slides, and the lens holding frame 2 itself remains substantially in that position, and only the drive shaft 9 moves. Thereafter, when the electrostrictive element 8 is slowly contracted, the sliding member 5 with the lens holding frame 2 moves along the Z axis + direction (FIG. 1) due to surface friction between the peripheral surface of the drive shaft 9 and the sliding surface 5a of the sliding member 5. See). By repeating this expansion and contraction operation, the lens holding frame 2 is displaced in the Z axis + direction. Similarly, when the electrostrictive element 8 is slowly extended and then rapidly contracted, the lens holding frame 2 moves in the Z-axis direction (see FIG. 1). At this time, in order to displace the electrostrictive element 8, the circuit board 13 shown in FIGS. 5 and 6 controls the electrostrictive element 8 by inputting an asymmetrical voltage waveform such as a rectangular wave or a sawtooth wave.

  Specifically, for example, when an asymmetric voltage pulse whose fall time is at least four times longer than the rise time is applied to the electrostrictive element 8, the friction between the peripheral surface of the drive shaft 9 and the sliding surface 5 a of the sliding member 5 occurs. When the pulse falls, the drive shaft 9 and the sliding member 5 return to the starting position while being engaged, so that the drive shaft 9 and the sliding member 5 move relative to each other at the time of the rise of the pulse. When the voltage is applied in the opposite direction, the electrostrictive element 8 is deformed in the opposite direction, and therefore the drive shaft 9 and the sliding member 5 move in the opposite directions. At this time, the spring receiver 6, the stable weight member 3, and the fixed frame 4 are fixed, and only the drive shaft side tip of the spring member 7 faces in the − direction.

  FIG. 3A shows a state in which the lens holding frame 2 is most displaced in the Z-axis − direction, and FIG. 6B shows a state in which the lens holding frame 2 is most displaced in the Z-axis + direction. The displacement width of the lens holding frame 2 can be freely set according to the length of the drive shaft 9. Further, the lens holding frame 2 can be moved minutely by the control of the linear actuator within the range of the displacement width set based on the drive shaft 9.

  In this way, the electrostrictive element applies a signal voltage that continuously deforms, thereby displacing the relative position due to surface friction between the drive shaft 9 and the sliding member 5 of the lens holding frame 2. Therefore, it is possible to perform minute positioning with excellent responsiveness and controllability, and it has a holding torque (or holding force) when no power is supplied, it has excellent advantages such as quietness, small size and light weight. .

  The above is the operation principle of the electrostrictive element 8 in the camera module 1 of the present embodiment. Next, the configuration of the camera module of the present embodiment will be described in more detail with reference to FIGS.

FIG. 4 is a view showing a contact state between the sliding member and the drive shaft. As shown in the side sectional view of FIG. 4A, the sliding member 5 has a concave shape on the side facing the drive shaft 9. There are three gaps 11, each of which has one place at the top end of the sliding member 5, one place at the bottom end, and the top end and bottom end in the axial direction of the drive shaft 9. These gaps are provided at a predetermined distance in the axial direction. 4C, the gap 11 is formed in a semi-annular shape.
In the gap located at the uppermost part and the lowermost part, a dust collecting member 10 having a sectoral fan shape is provided as shown in the plan sectional view of FIG. The sliding load of the dust collecting member 10 may be a load that is sufficiently smaller than the friction of the sliding member 5 and sufficient to collect the scraps. Further, the adhesive member 11 is preferably provided in a gap located between the sliding members 5.

The surface of the sliding member 5 that slides with the drive shaft 9 is the two sliding surfaces 5a excluding the gap. Therefore, the sliding member 5 side has a dust collecting member 10 with respect to the axial direction of the drive shaft. The sliding surface 5a, the adhesive member 11, the sliding portion 5a, and the dust collecting member 10 are arranged in this order so that the axial thicknesses thereof are substantially equal. In this way, by taking the sliding member 5 wider in cross section than the sliding surface, scattering of shavings and the like is suppressed.
Further, as other sliding surfaces of the member, the inner peripheral surface corresponding to the substantially semi-circular inner arc of the dust collecting member 10 and the sliding portion 4a of the fixed frame 4 become the sliding surfaces with the drive shaft. . At this time, it is preferable that the friction with the fixed frame 4 is small for improving the slidability and reducing the shavings, and that there is some friction with the sliding member 5 for reducing the driving loss. As a specific example, the surface of the drive shaft 9 that contacts the sliding member 5 may be processed to be rougher than the non-contact surface. It is also preferable for the drive shaft 9 to process the friction coefficient on the sliding surface 4a on the fixed frame 4 side lower than the friction coefficient on the sliding surface 5a on the sliding member 5 side. For example, the drive shaft 9 may be formed of a resin material having low friction using fluorine-containing polycarbonate or PPS, or the sliding surface 4a may be coated. Furthermore, a lubrication treatment is applied to the surface of the drive shaft 9 that slides on the sliding surface 4a of the fixed frame 4, and the surface of the sliding member 5 that slides on the sliding surface 5a is lubricated. It is also preferable to omit the processing.

  In the present embodiment, three gaps are provided in the axial direction of the drive shaft, dust collecting members 10 are provided at the uppermost and lowermost two locations, and the sliding member 5 is provided at two locations with the drive shaft 9. By adopting a configuration in which frictional engagement is performed, the sliding portions are dispersed to prevent the generation of shavings and to stabilize the optical axis of the lens. Moreover, it is good to arrange | position the adhesion member 11 between the two dust collection members 10, and this can arrange | position this adhesion member 11 without adding the arrangement | positioning space of the adhesion member 11 separately.

The camera module of the present embodiment is not limited to the above-described configuration, and any configuration may be used as long as the dust collecting member 10 is disposed in the vicinity of the sliding member 5. Even when scraps generated by sliding with the moving member 5 or deposits such as corrosive substances generated by corrosive gas or acid gas are captured by the dust collecting member 10 disposed in the vicinity of the sliding surface, It is possible to prevent the lens from becoming dirty as dust, and ghosts and flares, etc. As a result, the frictional force between the drive shaft and the sliding member must be maintained stably and appropriately even during long-term use. It is possible to prevent malfunction of the linear actuator. Furthermore, according to the present embodiment, a camera module having an autofocus (AF) function and a zoom function can be configured to be small and lightweight. The vicinity of the sliding member may be any position on the side of the sliding member 5 facing the drive shaft 9, and includes a position facing the electrostrictive element 8.
The dust collecting member 10 may be arranged such that a gap is provided on the side of the sliding member 5 facing the drive shaft 9, and the dust collecting member 10 may be provided in the gap. 5 may be provided on the side in contact with the drive shaft 9 or the electrostrictive element 8 on the sliding direction end side.
Further, a clearance is provided in a direction perpendicular to the sliding direction on the side where the sliding member 5 faces the drive shaft 9, and the dust collecting member 10 is disposed in the clearance so as to contact the drive shaft 9. Space can be achieved and the size can be reduced. Further, at least two gaps between the sliding members 5 are provided on both ends of the drive shaft 9 in the axial direction, and the dust collecting members 10 are disposed in the gaps at the two places. Thus, by arranging the dust collecting members on the upper and lower end portions of the drive shaft where the shavings are likely to be generated, this can be supplemented before the shavings are scattered.

  The dust collecting member 10 is preferably disposed on the electrostrictive element side end of the sliding member 5 and on the side facing the drive shaft 9 or the electrostrictive element 8 circumferential surface. Thus, by arranging the dust collecting member 10 at the end portion on the electrostrictive element side, it is possible to effectively collect the generated scraps. Furthermore, it is preferable to dispose the dust collecting member 10 at the opposite end portion of the sliding member 5 together with the electrostrictive element 8 side, whereby the dust collecting member 10 is disposed at both ends of the sliding member 5 in the drive axis direction. It is provided and more effective dust collection is possible. At this time, the dust collecting member 10 may be provided in both ends of the sliding member 5 with a gap between them, or may be attached to both ends of the sliding member 5.

Further, the surfaces of the sliding member 5 and the dust collecting member 10 that are in contact with the drive shaft 9 are formed in a substantially semi-annular shape with an arc cross section so that the sliding member 5 is supported by biasing from only one direction. In addition, the contact property to the drive shaft 9 can be maintained high, and the dust collecting member 10 has an arcuate cross section similar to the slide member 5, so that the slide member 5 and the drive shaft can be maintained. It is possible to reliably collect the shavings generated on the sliding surface 9 and improve the dust collection performance.
The dust collecting member 10 may be any member that can collect and hold shavings while being in contact with the drive shaft 9 by selecting a material with low repulsion, low load, little secular change, and many air layers. . For example, a structure having a large number of minute voids in the member, such as a foamed member such as a sponge-like member or a fibrous member, and collecting and holding scraps by the minute voids may be used. The material may be a foamable polymer material such as moquette, sponge, or urethane. Alternatively, the flocked paper, the flocked cloth, or the base may be directly applied to the surface facing the drive shaft 9.
Furthermore, two or more gaps of the sliding member 10 are provided in the axial direction of the drive shaft 9, and the adhesive member 11 is disposed in at least one of the gaps, so that the dust collecting member 10 can collect the gap. It becomes possible to adhere and collect uncut scraps with the adhesive member 11, and the dust collection performance is further improved.
The adhesive member 11 may be any member that does not abut against the drive shaft and adheres scraps and floating dust to the surface. The adhesive member 11 is an acrylic type with little secular change, a rubber type used for high weight, or a heat resistant material. A silicon-based material that is useful for use may be used, but an acrylic pressure-sensitive adhesive material that is inexpensive, chemically stable, and has no structural aging is suitable.

Since the drive control means comprising the electrostrictive element 8 and the drive shaft 9 in this embodiment is a friction drive type, the drive shaft surface, the sliding portion 5a of the sliding member 5, and the sliding portion 4a of the fixed frame 4 are arranged. When contacted, scraped scraps may be generated, and the scraped scraps may contaminate the lens as dust to produce ghosts and flares, or may cause deposits such as corrosive substances generated by corrosive gas or acidic gas. The dust collecting member 10 is provided in order to collect this deposit and prevent it from scattering.
In the present embodiment, as an example, the dust collecting member 10 is disposed in a space provided at two locations above and below the sliding member 5 in the axial direction. Furthermore, an adhesive member is arranged in a space 11 provided at one location near the center in the axial direction. In this way, by arranging the dust collecting member 10 and the adhesive member in the vicinity where the shavings are generated, the scraps are collected on the dust collecting member 10 and attached to the adhesive member to effectively prevent scattering. Can do.
It is also important not only to collect the generated scraps but also to prevent the scraps from coming out. As described above, the portion where the drive shaft 9 and the sliding portion 4a of the fixed frame 4 come into contact with each other is important. By smoothing the surface and roughening the surface where the driving shaft 9 and the sliding surface 5a of the sliding member 5 abut, the scraped dust does not occur on the side where the dust collecting member 10 or the adhesive member is not provided. It is good to do so.

  As described above, the embodiment of the camera module shown in FIGS. 1 to 4 is a configuration for driving the single lens holding unit 2, and each of the plurality of lenses constituting the zoom lens is used as such a camera module, for example. It is possible to construct a camera module that can perform zooming and focusing at the same time by preparing the lens so as to correspond to the above and driving the lens to a predetermined position according to the focal length.

  In addition, if the camera module of the present invention is a single-focus camera module and an image sensor such as a CCD is prepared at the focal position of the lens, an information terminal such as a mobile phone with a camera function or a surveillance camera having an autofocus function, etc. It is possible to apply to.

  FIG. 5 and FIG. 6 show the embodiment in this case. The camera module shown in FIGS. 5 and 6 is an explanatory diagram of an example of a structure in which the above-described camera module is combined with an imaging device such as a CCD to form a single-focus independent camera module, and FIG. ) Is a left side view, (b) is a top view, (c) is a right side view, (d) is a perspective view from the lower left, (e) is a perspective view from the upper right, and (f) is (b). A sectional view taken along the line A-A in FIG. 5, (g) is a sectional view taken along the line BB in (b), and (h) is a sectional view taken along the line CC in FIG.

  6A shows the camera module 1 that has been adjusted by incorporating the above-described imaging lens, lens moving mechanism, and various electrical components. FIG. 6B shows the camera module 1 covered with a cover 14. It is a figure.

  In FIG. 5 and FIG. 6, the same components as those in FIG. 1 to FIG. In the figure, 13 is a substrate on which an image sensor such as a CCD is mounted, 14 is a camera module cover, 15 is an exposed portion of the lens, 16 is a communication FPC for electrical connection with a portable device or the like on which the camera module is mounted, 17 Is a Hall element for detecting the position of the lens holding frame 2, 18 is a magnet for the Hall element 17, 19 is a filter for protecting the image sensor 20 such as a CCD, and 21 is a guide for holding the Hall element 17 and the like. Is the axis.

  In the camera module shown in FIGS. 5 and 6, the fixing frame 4 in the camera module described in FIGS. 1 to 4 is fixed to the base 22 provided on the substrate 13 as shown in FIG. Further, the hall element 17 fixed to the lens holding frame 2 and the shaft 21 for moving the magnet 18 are similarly fixed to the base body 22 as shown in FIG. It also serves as.

  Then, as shown in the sectional view of FIG. 5 (f), the imaging device 20 such as a CCD and the filter 19 are accommodated in the base 22, and the whole is covered with a cover to obtain a camera module as shown in FIG. Is.

  By configuring the camera module in this manner, the lens holding frame 2 can be driven by the electrostrictive element 8 as described with reference to FIGS. 1 to 4, and the lens is held by the Hall element 17 and the magnet 18. Since it is possible to accurately detect the current position of the frame 2, it is possible to provide a camera module that is very small in size but can be focused quickly and accurately even though it is a single focus.

  FIG. 7 is an example of an information terminal equipped with the camera module 1 described above. The information terminal shown in FIG. 7 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. 7 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 1 as shown by a broken double circle in the figure, and when a predetermined button of the operation unit 51 is operated, the camera module 1 takes an image, The captured image is displayed on the display 52, for example. Note that the upper side of the camera module 1 shown in FIG. 1 is directed to the outside of the second case portion 54. That is, the second case portion 54 is formed with an opening that exposes the first lens group 2 held by the third lens holding portion 20 in the camera module 1. A battery unit, a communication unit, and the like are accommodated in the case unit 53, and the thickness dimension of the second case unit 54 is substantially regulated by the height of the camera module 1.

  As described above, according to the present embodiment, it is possible to provide a small and lightweight camera module incorporating an autofocus (AF) function and a zoom function and an information terminal equipped with the camera module. .

  A camera module incorporating an autofocus (AF) function or a zoom function can be configured to be small and lightweight, and is optimal as a camera module in various small information terminals.

It is a schematic sectional drawing of the camera module of the drive part in this embodiment. FIG. 2 is a perspective view (A) of the camera module of FIG. 1 viewed from the subject-side lens direction and a perspective view (B) of the camera module viewed from the image sensor direction. FIG. 5 is an operation explanatory diagram of the camera module according to the present embodiment, showing a state where the lens is on the most telephoto (tele) side (a) and a state (b) where the lens is also on the widest (wide) side. It is a figure which shows the contact state of a sliding member and a drive shaft, and is side sectional drawing (a), plane sectional drawing (b), and principal part sectional drawing (c). BRIEF DESCRIPTION OF THE DRAWINGS In structure explanatory drawing of the camera module which concerns on this embodiment, a left view (a), a top view (b), a right view (c), a perspective view from the lower left (d), a perspective view from the upper right ( It is an AA line sectional view (f) in (e) and (b), a BB line sectional view (g) in (b), and a CC line sectional view (h) in (b). It is the perspective view (a) which shows the whole structure of the camera module of this embodiment, and a perspective view (b) at the time of mounting | wearing with a cover. It is a figure which shows roughly an example of the mobile telephone with which the camera module of this embodiment was integrated.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera module 2 Lens holding frame 6 Spring holder 3 Stable weight member 4 Fixed frame 4a Sliding surface 5 Sliding member 5a Sliding surface 7 Spring member 8 Electrostrictive element 9 Drive shaft 10 Dust collecting member 11 Adhesive member 12 Lens 13 Circuit Base 14 Cover 16 Contact flexible printed circuit board 17 Hall element 18 Magnet 19 Filter glass 20 Image sensor 21 Guide shaft

Claims (13)

An electrostrictive element, a drive shaft that is connected to the electrostrictive element at one end in the axial direction, and reciprocates or expands and contracts in the axial direction by a voltage applied to the electrostrictive element, and at least a peripheral surface of the drive shaft A lens holding part coupled to a sliding member that frictionally engages a part of the camera module,
A camera module, wherein a dust collecting member is disposed in the vicinity of the sliding member.   The gap is provided in a direction perpendicular to the sliding direction on the side where the sliding member faces the drive shaft, and the dust collecting member is disposed in the gap so as to contact the drive shaft. The camera module according to 1.   The dust collecting member is disposed on an end of the sliding member on the electrostrictive element side and on a side facing the drive shaft or the circumferential surface of the electrostrictive element. The camera module described.   The camera module according to claim 2, wherein the sliding member is frictionally engaged with the drive shaft at two locations.   5. The gap between the sliding members is provided at least at two axial ends of the drive shaft, and the dust collecting member is disposed in each of the two gaps. The camera module according to Crab.   5. The camera module according to claim 2, wherein surfaces of the sliding member and the dust collecting member that are in contact with the drive shaft are formed in a circular arc shape in cross section.   The camera module according to claim 2, wherein two or more gaps of the sliding member are provided in the axial direction of the drive shaft, and an adhesive member is disposed in at least one of the gaps.   The camera module according to claim 4, wherein an adhesive member is disposed between the two locations.   The camera module according to claim 1, wherein a surface of the drive shaft that is in contact with the sliding member is rougher than a non-contact surface.   The drive shaft is supported by being sandwiched between the sliding member and a fixed frame disposed on the opposite side of the sliding member, and the friction coefficient on the sliding surface on the fixed frame side is determined by the sliding 2. The camera module according to claim 1, wherein the camera module is processed so as to be lower than a coefficient of friction on a sliding surface on a member side.   The drive shaft is supported by being sandwiched between the sliding member and a fixed frame disposed on the opposite side of the sliding member, and the surface of the drive shaft on the side sliding on the fixed frame is supported. The camera module according to claim 1, wherein a lubrication process is performed on the surface of the sliding member, and the lubrication process is omitted on a surface that slides on the sliding member.   2. The camera module according to claim 1, further comprising an elastic member that urges the sliding member in a direction in contact with the drive shaft. A lens holding unit for holding at least one optical lens;
An electrostrictive element is connected to one end side in the axial direction, and a drive shaft that reciprocates or expands and contracts in the axial direction by a voltage applied to the electrostrictive element;
A sliding member connected to the lens holding portion and frictionally engaged with at least a part of a peripheral surface of the drive shaft;
A camera module comprising: at least one dust collecting member disposed in a gap provided in a direction perpendicular to the sliding direction on the side facing the drive shaft of the sliding member;
An operation member, a display member, a battery, a communication unit,
A housing that houses the camera module, the operation member, the display member, the battery, and the communication unit, and that regulates the thickness of the housing to a height of the camera module. An information terminal characterized by

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