The application is application No. is 2012102330469, and the applying date is on 07 06th, 2012, and invention and created name isThe divisional application of the patent of " actuator and the camera model with the actuator ".
Invention content
In view of this, it is necessary to which a kind of actuator of achievable exact focus and the camera mould with the actuator are providedBlock.
A kind of actuator, including pedestal, fixed frame, movable frame and driving unit.The fixed frame is fixedly arranged on describedOn pedestal, the movable frame is contained in the fixed frame and is carried on the pedestal.The movable frame includes one towards instituteState the supporting surface of pedestal.The driving unit includes SMA wire, controller, position sensor and guide bar.The two of the SMA wireEnd is fixed on the fixed frame, and the SMA wire includes the bending part between the both ends, and the bending part is supported with describedFace contradicts, and the guide bar passes through the movable frame and is fixed on the pedestal.The controller heats for applying electric currentSMA wire drives the movable frame to be moved along the guide bar to change the length of SMA wire.The position sensor is used to senseSensing result is simultaneously transmitted to the controller by the position of the movable frame.The controller is additionally operable to according to the sensing resultAdjust the size of the electric current.
A kind of camera model, including actuator and lens unit as described above, the lens unit is contained in describedIn movable frame.
Compared to prior art, the actuator and the camera model have position sensor simultaneously can be according to position sensingThe sensing result adjustment control electric current of device, so as to improve focusing precision.
Specific embodiment
It please refers to Fig.1 to Fig.3, is the camera model 100 of an embodiment of the present invention.The camera model 100 includes causingDynamic device 200 and lens unit 15.It is single that the actuator 200 includes pedestal 10, shrapnel 11, fixed frame 12, movable frame 14 and drivingMember 16.
The pedestal 10 is substantially in tabular.The center of the pedestal 10 offers circular light hole 101.It is describedPedestal 10 includes upper surface 102.One corner of the upper surface 102 is formed with protrusive board 103, is formed on the protrusive board 103There is pillar 104.Another corner of the upper surface 102 opposite with the pillar 104 forms a mounting hole 105.On describedIt is formed with positioning column 106 and location hole 107 respectively at other two corner on surface 104.
The shrapnel 11 is in round, and the internal diameter of shrapnel 11 is more than the diameter of light hole 101.It is symmetrically formed on the shrapnel 11There are two lugs 111, a through-hole 112 is formed on each lug 111.
The 12 substantially square tubular of fixed frame, it is adjacent to each other including two the first side walls 120 and two adjacent to each otherSecond sidewall 121.Holding tank 122 is formed on the first side wall 120.The first side wall 120 and the second sidewall 121Between corner madial wall on be formed with sliding slot 123.Pillar there are two being formed on the outer surface of each second sidewall 121124 and a holding tank 125.The pillar 124 extends close to the first side wall 120, the holding tank 125 from the pillar 124To another second sidewall 121.The lower part of corner between two second sidewalls 121 is formed with bit-avoiding slot 126, and top is formed withReceiving hole 127, receiving hole 127 are stepped hole.It is also formed with swashing at pillar 124 on the outer surface of each second sidewall 121Light straight forming line (LDS, Laser Direct Structuring) 128, each LDS lines 128 are extended to from second sidewall 121Corresponding the first side wall 120.The location hole and correspondence of corresponding pedestal upper positioning column 106 are formed on the bottom surface of the fixed frame 12The positioning column (not shown) of location hole 107.
The 14 generally circular tubular of movable frame, the interior receiving lens unit 15 of movable frame 14, in the present embodiment, mirrorHead unit 15 and movable frame 14 are fixed together in a manner that screw thread is spirally connected.Lens unit 15 includes lens barrel 150 and is contained inEyeglass 151 in lens barrel 150.Two sliding blocks 141 relative to each other are formed on the outer surface 140 of movable frame 14, one, which is located at two, slides142 and one holding tank 143 opposite with lug 142 of arc step shape lug between block 141.One side is formed on lug 142To the supporting surface 144 of pedestal 10.A ladder hole 145 is formed in lug 142.
The driving unit 16 includes circuit board 160, controller 161, the position sensor being installed on circuit board 160162nd, magnet 163, two resistance clamping pieces 164, a shape memory alloy wire (Shape Memory Alloy, SMA) 165, one are ledDraw 166 and one elastic component 170 of bar.Wherein, in the present embodiment, position sensor 162 is Hall magnetic sensor.ResistanceClamping piece 164 is metallic conduction shrapnel, the holding tank 167 that is formed through metal bending is formed on resistance clamping piece 164 and through goldBelong to the plumb joint 168 extended to form, mounting hole 169 is also formed on resistance clamping piece 164.Elastic component 170 is spring.
Upon assembly, shrapnel 11 is placed on pedestal 10 so that pillar 104 passes through a through-hole 112 of shrapnel 11, guide bar166 pass through another through-hole 112 of shrapnel 11 to enter in the mounting hole 105 of pedestal 10, so as to which shrapnel 11 is fixed on pedestal 10；Magnet 163 is fixed on by adhesive type in the holding tank 143 of movable frame 14, movable frame 14 is fixed on bullet by adhesive meansOn piece 11 so that guide bar 166 passes through the ladder hole 145 on the lug 142 of movable frame 14, and elastic component 170 is placed on guide barOn 166,170 part of elastic component is placed in ladder hole 145；Fixed frame 12 is placed on pedestal 10 so that sliding block 141 is placed inIn sliding slot 123, lug 142 is placed in bit-avoiding slot 126, and guide bar 166 passes through receiving hole 127, by adhesive means by fixed frame12 are fixed on pedestal 10；Two resistance clamping pieces 164 are fixed on fixed frame 12 by the cooperation of mounting hole 169 and pillar 124On, the plumb joint 168 of resistance clamping piece 164 is connect by the method for welding with LDS lines 128；SMA wire 165 is placed in fixed frameIn 12 holding tank 125, the both ends of SMA wire 165 are clamped in respectively in the holding tank 167 of resistance clamping piece 164,165 liang of SMA wirePart bending between end bypasses the lug 142 of movable frame 14 and is contradicted with supporting surface 144；Circuit board 160 is fixed on fixationOn frame 12, position sensor 162 passes through holding tank 122 opposite with magnet 163, and circuit board 160 passes through welding manner and LDS lines128 connections, so as to the assembling of finish actuator 200.
When start, controller 161 provide driving current, drive current through LDS lines 128, resistance clamping piece 164 and addHot SMA wire 165, SMA wire 165 is heated to be shortened, so as to which movable frame 14 be driven to be moved to the direction far from pedestal 10, so as to complete to becomeIt is burnt.Due to the limitation of guide bar 166 and through-hole 145 so that movable frame 14 can only be moved along the direction that guide bar 166 extends,So as to which the present invention only needs movable frame 14 can be driven to complete zoom using a SMA wire.
The length and temperature that SMA wire 165 is shunk have correspondence, however, due to the influence of environment temperature, even if givingSMA wire 165 applies identical driving current, and the degree difference that SMA wire 165 is heated is also resulted in environment temperature difference,The degree difference shunk so as to SMA wire 165.In order to realize accurate zoom, present invention uses position sensors 162.MovableIn the moving process of frame 14, position sensor 162 senses the change of magnetic field strength for being fixed on the magnet 163 in movable frame 14, fromAnd the change in location of movable frame 14 being sensed, and result is returned into controller 161, controller 161 is adjusted according to sensing result and is drivenStreaming current, so as to fulfill exact focus.For example, when the distance that movable frame 14 moves is more than preset distance, controller 161 is reducedDriving current, so that SMA wire 165 is elongated, so as to which movable frame 14 be controlled to be moved to preset distance；When by the scheduled timeWhen movable frame 14 has not moved into preset distance, controller 161 increases driving current, so that SMA wire 165 further contractsIt is short, so as to which movable frame 14 be controlled to be moved to preset distance.
When movable frame 14 is to far from the movement of 10 direction of pedestal, 11 applied elongation of shrapnel, 170 forced compression of elastic component.WhenWhen controller 161 stops providing driving current, the cooling elongation of SMA wire 165,170 elastic recovery of shrapnel 11 and elastic component, so as to driveMovable frame 14 is made to return to initial position.
It is appreciated that the fixed frame 12 is not limited to present embodiment is fixedly arranged on the pedestal 10 by glued modeOn, it can also be fixedly arranged on by snap fit on the pedestal 10.
It is appreciated that the position sensor 162 is not limited to the Hall magnetic sensor of present embodiment, may be used alsoTo be other types of position sensor, such as photoelectrical position sensor.
In short, those skilled in the art it should be appreciated that more than embodiment be intended merely to illustrate thisInvention, and be not used as limitation of the invention, as long as within the spirit of the present invention, to above example instituteThe appropriate change and variation made all is fallen within the scope of protection of present invention.