CN101539653A

CN101539653A - Lens driving device

Info

Publication number: CN101539653A
Application number: CN 200810066113
Authority: CN
Inventors: 张国际; 刘宝廷
Original assignee: Johnson Electric Shenzhen Co Ltd
Current assignee: Johnson Electric Shenzhen Co Ltd
Priority date: 2008-03-19
Filing date: 2008-03-19
Publication date: 2009-09-23
Anticipated expiration: 2028-03-19
Also published as: CN101539653B

Abstract

The invention provides a lens driving device, which comprises a fixed part and a moving part, wherein the fixed part comprises a base and an upper cover, and the moving part comprises a lens bracket for accommodating a lens; the base and the upper cover comprise radial extending parts and axial extending parts respectively; the fixed part also comprises a magnet which is fixed between the radial extending parts of the base and the upper cover and is polarized along the optical axis direction of the lens; and the moving part also comprises a coil which is fixed on the lens bracket and is positioned between the axial extending parts of the base and the upper cover. In the lens driving device, because the magnet is polarized along the optical axis direction of the lens, the magnet can be made thinner along the optical axis direction of the lens for contributing to reducing the size of the lens driving device along the optical axis direction; and the N and S poles of the magnet are clung to the base and the upper cover respectively to reduce the magnetic leakage on a radial plane so that the utilization rate of a magnetic field is higher.

Description

Lens driving apparatus

Technical field

The invention belongs to the camera technique field, relate in particular to a kind of lens driving apparatus.

Background technology

Continuous development along with science and technology, products such as digital camera, mobile phone camera or Digital Video are more and more higher to the requirement of zoom, focusing in the digital vedio recording field, at the image that guarantees high image quality simultaneously, volume requirement to zoom, focalizer is also more and more stricter, and zoom, focalizer develop towards microminiaturized direction.

Now on the market a kind of lens driving apparatus commonly used as shown in Figure 3, described lens driving apparatus comprises lens bracket 1, iron-clad 2, magnet 3 and coil 4, coil 4 is fixed on the lens bracket 1.Described iron-clad 2 is a circular one-piece construction, its have outer ring 2a, the inner ring 2b in the outer ring and be connected in the top, outer ring and the inner ring top between the 2c of yoke portion.Described magnet 3 is fixed on the inside surface of iron-clad 2 outer ring 2a, and the inner ring 2b of iron-clad 2 is between coil 4 and lens bracket 1.Magnet 3 is along the camera lens radial polarised, and the flow direction of magnet 3 is shown in the direction of arrow among the figure.

Because magnetic field intensity depends on that magnet at the area perpendicular to the xsect of its polarised direction, along under the certain situation of camera lens circumferential size, depends on the height of magnet at magnet.Like this, in above-mentioned prior art, magnet 3 can not be done thin in short transverse.There is leakage field in traditional structure magnetic field on the magnet sagittal plane,

Summary of the invention

In order to solve the problems of the technologies described above, the invention provides a kind of lens driving apparatus, it comprises fixed part and motion parts, described fixed part comprises pedestal and loam cake, described motion parts comprises the lens bracket that is used to accommodate camera lens, described pedestal and loam cake comprise radially extension respectively and extend axially portion, described fixed part comprises that also magnet is fixed in radially between the extension of described pedestal and loam cake, described magnet is along the camera lens optical axis direction polarization, described motion parts also comprises the coil that is fixed on the lens bracket, and described coil extends axially between the portion described pedestal and loam cake.

The present invention further is improved to: described pedestal and loam cake are square, and described magnet is arranged at described square place, four angles.

The beneficial effect that illustrated embodiment of the present invention has is: because magnet is along the camera lens optical axis direction polarization, magnet along the camera lens optical axis direction can do thinner, help reducing the size of lens driving apparatus along optical axis direction; Because magnet is along the camera lens optical axis direction polarization, the N of magnet and the S utmost point are close to pedestal and loam cake respectively, thus can reduce on the sagittal plane leakage field, the magnetic field utilization ratio is higher; Because described magnet is arranged at the place, four angles of loam cake and pedestal, therefore, can effectively utilize the space, thereby make the lens driving apparatus compact conformation.

Description of drawings

Fig. 1 is the package assembly synoptic diagram of the lens driving apparatus that provides of the embodiment of the invention;

Fig. 2 is the cross-sectional schematic of the lens driving apparatus that provides of the embodiment of the invention along the A-A line of Fig. 1;

Fig. 3 is the cross-sectional schematic of a kind of lens driving apparatus of providing of prior art.

Embodiment

In order to make technical matters to be solved of the present invention, technical scheme and beneficial effect clearer,, the present invention is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.

See also Fig. 2 and Fig. 3, a kind of lens driving apparatus that the embodiment of the invention provides comprises fixed part and motion parts, described fixed part comprise pedestal 10, loam cake 30 and be fixed in pedestal 10 and loam cake 30 between magnet 50; Described motion parts comprises the lens bracket 70 that is used to accommodate camera lens, and fixed cover places the coil 90 on the lens bracket 70.

Described pedestal 10 can comprise radially

extension

10a, 30a respectively with loam cake 30, and the columned 10b of portion, the 30b of extending axially, described lens bracket 70 telescopicallies are contained in the 30b of the portion that extends axially of loam cake 30, described coil 90 is between the 10b of the portion that extends axially, the 30b of pedestal 10 and loam cake 30, and the 30b of the portion that extends axially of loam cake 30 is between coil and lens bracket 70.As a preferred embodiment of the present invention, described pedestal 10 is square with loam cake 30, and described magnet 50 is four, is individually fixed in described square place, four angles.Certainly, described pedestal 10 can also be other shapes with loam cake 30.

Described magnet 50 is along the camera lens optical axis direction polarization, the close pedestal 10 radially end of extension 10a is the N utmost point, the close loam cake 30 radially end of extension 30a is the S utmost point, the magnetic flux that sends from the N utmost point of magnet 50 passes radially extension 10a, the 10b of the portion that extends axially of pedestal 10, coil 90, the 30b of the portion that extends axially of loam cake, the radially extension 30a of loam cake of pedestal 10 successively, returns the S utmost point of magnet 50 then.Certainly, described magnet 50 also can be polarized near pedestal 10 radially the end of extension 10a be the S utmost point, the close loam cake 30 radially end of extension 30a is the N utmost point, the magnetic flux that sends from the magnet 50N utmost point returns the S utmost point of magnet 50 then successively through radially extension 30a, the 30b of the portion that extends axially of loam cake, coil 90, the 10b of the portion that extends axially of pedestal 10, the radially extension 10a of pedestal 10 of loam cake.

In the invention described above embodiment, because magnet 50 is along the camera lens optical axis direction polarization, magnetic field intensity is not subjected to the size impact of its axial direction, therefore, magnet 50 along the camera lens optical axis direction can do thinner, help reducing the size of lens driving apparatus along optical axis direction; Because magnet 50 is along the camera lens optical axis direction polarization, the N of magnet 50 and the S utmost point are close to pedestal 10 and loam cake 30 respectively, therefore can reduce the leakage field of magnet 50 on the sagittal plane, and the magnetic field utilization ratio is higher; And, because being arranged at loam cake 30, described magnet 50 locates with four angles of pedestal 10, therefore, can effectively utilize the space, thereby make the lens driving apparatus compact conformation.

The above only is preferred embodiment of the present invention, not in order to restriction the present invention, all any modifications of being done within the spirit and principles in the present invention, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.

Claims

1, a kind of lens driving apparatus, comprise fixed part and motion parts, described fixed part comprises pedestal and loam cake, described motion parts comprises the lens bracket that is used to accommodate camera lens, it is characterized in that: described pedestal and loam cake comprise radially extension respectively and extend axially portion, described fixed part comprises that also magnet is fixed in radially between the extension of described pedestal and loam cake, described magnet is along the camera lens optical axis direction polarization, described motion parts also comprises the coil that is fixed on the lens bracket, and described coil extends axially between the portion described pedestal and loam cake.

2, lens driving apparatus as claimed in claim 1 is characterized in that: described pedestal and loam cake are square, and described magnet is arranged at described square place, four angles.

3, lens driving apparatus as claimed in claim 1, it is characterized in that: the magnetic flux that sends from the magnet N utmost point is got back to the S utmost point of magnet then successively through the portion that extends axially of the radially extension of pedestal, pedestal, coil, the portion that extends axially of loam cake, the radially extension of loam cake.

4, lens driving apparatus as claimed in claim 1, it is characterized in that: the magnetic flux that sends from the magnet N utmost point is got back to the S utmost point of magnet then successively through the portion that extends axially of the radially extension of loam cake, loam cake, coil, the portion that extends axially of pedestal, the radially extension of pedestal.

5, lens driving apparatus as claimed in claim 1 is characterized in that: the portion of extending axially of described loam cake is positioned between coil and the lens bracket.