Lens driving device

The present disclosure provides a lens driving device which is small and has good focus adjustment and hand shake correction. The lens driving device includes: a case; a lens module; a support frame; a spring leaf; a support part connecting the support frame with the fixing base in such a manner that the support frame is freely movable relative to the fixing base in a direction orthogonal to an optical axis of a lens; a magnet steel; a first driving coil; and a second driving coil. Under an electromagnetic interaction between the second driving coil and a second portion of the magnet steel opposite to the second driving coil, the support frame moves relative to the fixing base in the direction orthogonal to the optical axis of the lens.

TECHNICAL FIELD

The present disclosure relates to the technical field of driving devices, and in particular, to a lens driving device having an anti-shake function.

BACKGROUND

With rapid development of photography technologies, lens driving devices have been widely used in a large number of photographic devices. Application of the lens driving device in various portable electronic devices, such as mobile phones, tablet computers, etc., has been especially accepted by consumers.

A driving mechanism of a lens driving device suitable for a general portable electronic device is generally formed by a coil and a permanent magnet, and the coil is fixed to an outer circumference of a camera lens frame. When a current is applied to the coil, the coil drives the camera lens frame to move in an optical axis direction of the lens under an electromagnetic force, thereby achieving focusing. However, when a user holds an electronic device for photographing, it inevitably causes shake of the lens driving device due to hand shake. Therefore, the lens sometimes moves continuously in a direction orthogonal to an optical axis of the lens. Thus, in the lens driving device, an influence caused by the hand shake cannot be avoided, resulting in a deterioration in the quality of a captured image.

Further, in a conventional device for correcting hand shake, it is necessary to use a driving circuit disposed at a bottom portion to drive a center of gravity of a lens module located at a higher position facing away from the driving circuit. In order to correct shake in the direction orthogonal to the optical axis, it may require a bigger force.

Therefore, it is needed to provide a new lens driving device that can solve the above problems.

DESCRIPTION OF EMBODIMENTS

FIGS. 1 to 4are diagrams showing a lens driving device100according to the present disclosure.

The lens driving device100includes: a case10, a lens module30, a support frame20, a spring leaf50, a support part40, a magnet steel60, a first driving coil70and a second driving coil71.

The case10includes a receiving space14, and the case10includes: a fixing base13; a cover12for forming the receiving space14together with the fixing base13, and a connection line fixing base11for fixing a connection line80. For example, the cover12can be made of a metal material, and thus has great strength and high drop reliability.

The fixing base13includes a cylindrical holding member42and a second driving coil71fixed to the fixing base13.

The support frame20is received in the receiving space14of the case10, the lens module30is received in the support frame20, and the lens module30includes a lens (not shown).

The support part40supports the support frame20and the fixing base13in such a manner that the support frame20can freely move relative to the fixing base13in a direction orthogonal to an optical axis of the lens.

The support part40may be a ball. At least three balls40can be provided, and correspondingly a ball receiving surface41, on which the balls40are to be placed, is arranged at an upper portion of the support frame20. Rolling of the balls40enables the support frame20to freely move relative to the fixing base13in the direction orthogonal to the optical axis of the lens.

In an embodiment, the ball40can directly abut against the cover12, i.e., the ball receiving surface for the ball40can be a part of the cover12. For example, the cover12can include a bottom portion being the ball receiving surface for the ball40. In this way, there is no need for other components abutting against the ball, so that assembly efficiency and assembly stability can be improved.

Further, in another preferred embodiment, providing the connection line fixing base11with a second driving coil auxiliary part can improve an efficiency of an electromagnetic interaction.

The spring leaf50connects the lens module30with the support frame20.

The spring leaf50includes an upper spring leaf51and a lower spring leaf52that are respectively arranged on an upper surface portion and a lower surface portion of the lens module30along the optical axis direction of the lens.

The magnet steel60is mounted and fixed to the support frame20.

The lens driving device100is provided with a magnet yoke90, and the magnet yoke190is mounted and fixed to the fixing base13, and has functions of pulling the magnet steel60towards the optical axis direction and pulling the lens module towards a center of the optical axis when the lens module moves in a direction perpendicular to the optical axis direction.

The first driving coil70is mounted and fixed to the lens module30and is opposite to the magnet steel60.

The lens module30is provided with a protrusion31extending in a direction facing away from a center of the lens module. The first driving coil70is held at the protrusion31. The first driving coil70is opposite to the magnet steel60. Under an electromagnetic interaction between the first driving coil70and the magnet steel60, the lens module can move along the optical axis direction of the lens, thereby achieving focusing.

The second driving coil71is arranged at the fixing base13and is arranged correspondingly to an upper portion of the magnet steel60.

The second driving coil71can be a coil winding that is mounted and fixed on the fixing base13, or can be a conductive pattern directly formed on the fixing base13. Under an electromagnetic interaction between the second driving coil71and the magnet steel60, the support frame20can move relative to the fixing base13in the direction orthogonal to the optical axis of the lens, thereby achieving adjustment relating to movement of the optical axis of the lens.

In an embodiment, four first driving coils70can be provided. It should be noted that providing four first driving coils70is merely an embodiment for allowing those skilled in the art to completely understand the present disclosure, and the present disclosure is not limited to the embodiment in which the number of the first driving coils70is four.

Corresponding to the four first driving coils70, upper spring leaves51are arranged together with the four first driving coils70to be centrosymmetric with respect to the optical axis of the lens, i.e., being arranged at positions symmetrical with respect to a center line.

The lens driving device100is further provided with a connection line80.

The connection line80is connected to the spring leaf50. Each first driving coil70includes an end having a line end connected to a corresponding upper spring leaf51, and another end having a line end connected to the lower spring leaf52. Alternatively, a magnetism detecting element81including a first driving circuit can be connected to the line end of each first driving coil, and then the magnetism detecting element81including the first driving circuit is connected to the spring leaf50and to the connection line80.

The magnetism detecting element81including the first driving circuit is an example, and it can also be a driving IC capable of magnetism detection. The magnetism detecting element81including the first driving circuit detects magnetism of the magnet steel60corresponding to the magnetism detecting element, thereby detecting a position of the lens module30moving in the optical axis direction. This can achieve more efficient adjustment relating to the movement of the lens in the optical axis direction.

Similarly, corresponding to the first driving coils70, four magnet steels60and four second driving coils71are provided, and the four magnet steels60and the four second driving coils71are respectively arranged to be centrosymmetric with respect to the optical axis of the lens, i.e., being respectively arranged at positions symmetrical with respect to the center line.

The second driving coil71and a second driving coil auxiliary part73are electrically connected to a connection terminal15, and the connection terminal15is provided at the connection line fixing base and connected to an external component. However, the second driving coil71and the second driving coil auxiliary part73can also be connected to the magnetism detecting element82including a second driving circuit. Here, the magnetism detecting element82including the second driving circuit is merely an example, and it can also be a driving IC capable of magnetism detection. The magnetism detecting element82including the second driving circuit is located at a position corresponding to the magnet steel60, and can detect a position of the magnet steel60moving together with the support frame20.

When the optical axis of the lens moves or tends to move due to shake, a current can flow into four second driving coils71provided nearby a horizontal position of a center32of gravity of the lens module or into the second driving coil71and the second driving coil auxiliary part72. Since the second driving coil71and the second driving coil auxiliary part73are fixed, according to the law of action and reaction, the support frame20can on the one hand efficiently keep balance relative to a center of gravity of a moving object and on the other hand move relative to the fixing base13along the direction orthogonal to the optical axis of the lens, or can suppress the moving tendency of the optical axis of the lens. Therefore, movement of the optical axis of the lens can be adjusted.

The above-mentioned lens driving device100can also be used in a photographic device300for use in portable information device200such as a so-called smart cellphone, a so-called function cellphone or a tablet device shown inFIG. 5.

With the lens driving device100of the present disclosure, movement of the optical axis of the lens can be adjusted, so that a purpose of anti-shake can be achieved, thereby improving a quality of the captured image.

The above-described embodiments are merely preferred embodiments of the present disclosure and are not intended to limit the scope of the present disclosure. Any equivalent modification or variation made by those skilled in the art based on the present disclosure is included in the scope of the present disclosure.

REFERENCE SIGNS