TECHNICAL FIELD

Embodiments relate to a lens moving apparatus and a camera module including the same.

BACKGROUND

In recent years, IT products equipped with digital cameras, such as mobile phones, smart phones, tablet PCs, and laptop computers, have been actively developed. It is required for a camera module having such a digital camera to provide various functions, such as auto focusing, handshake correction, and zooming. In addition, efforts are being made to miniaturize high-pixel camera modules.

Meanwhile, there is a high necessity for shielding electromagnetic interference (EMI), including electrical noise generated from components, such as a coil or a sensor, included in a conventional camera module.

In addition, the conventional camera module cannot recognize the position of a subject. As a result, the resolving power of an actuator may vary based on hysteresis or repeatability. Consequently, the conventional camera module may have a problem in that it takes a long time to perform an auto focusing function.

BRIEF SUMMARY

Embodiments provide a lens moving apparatus capable of shielding electromagnetic interference and a camera module including the same.

Further, embodiments provide a camera module capable of rapidly and accurately performing an auto focusing function.

In one embodiment, a lens moving apparatus includes a bobbin equipped with at least one lens, a coil and a driving magnet arranged opposite to each other for moving the bobbin in an optical axis direction of the lens through interaction therebetween, a first circuit board for supplying electric current required by the coil, and a cover can and a base coupled to, contacted to, supported at, fixed to, or temporarily fixed to each other for forming a space in which the bobbin, the driving magnet, and the first circuit board are received, wherein the cover can is connected to a second circuit board having an image sensor mounted thereon.

The first circuit board may include an electromagnetic interference (EMI) shielding terminal for connecting the cover can to the second circuit board.

The cover can may include at least one can protrusion protruding in a first direction parallel to the optical axis, the at least one can protrusion being connected to the second circuit board. The base may include a protruding recess, which the at least one can protrusion is mounted to, inserted in, seated at, contacted to, coupled to, fixed to, temporarily fixed to, supported at, or located at. The at least one can protrusion may be connected to the second circuit board by soldering, conductive epoxy, or welding.

The lens moving apparatus may further include a housing member coupled to, seated at, contacted to, fixed to, supported at, or located at the base for supporting the driving magnet and the first circuit board.

The first circuit board may be located under the housing member.

The lens moving apparatus may further include a displacement sensing unit for sensing a first displacement value of the bobbin in the optical axis direction, wherein the first circuit board may be mounted to, inserted in, seated at, contacted to, coupled to, fixed to, supported at, or located at an outer surface of one lateral surface of the housing member.

The housing member may have a sensor through hole formed at the one lateral surface thereof, which the first circuit board is mounted to, inserted in, seated at, contacted to, coupled to, fixed to, supported at, or located at, such that the displacement sensing unit is inserted in, located at, or seated at the sensor through hole.

The lens moving apparatus may further include a sensing magnet located at a position corresponding to the displacement sensing unit and the sensor through hole.

The EMI shielding terminal may be plated with gold.

The cover can may be made of a metal.

The first circuit board may further include an I2C communication terminal and a power terminal for receiving external power.

The cover can may be a yoke cover can.

In another embodiment, a lens moving apparatus includes a bobbin equipped with at least one lens, a coil and a driving magnet arranged opposite to each other for moving the bobbin in an optical axis direction of the at least one lens through interaction therebetween, a first circuit board for supplying electric current required by the coil, a cover can and a base coupled to each other for forming a space in which the bobbin, the driving magnet, and the first circuit board are received, and a cover covered by the cover can for fixing and supporting the bobbin, the driving magnet being coupled in the cover, wherein the cover is connected to a second circuit board having an image sensor mounted thereon.

The first circuit board may include an EMI shielding terminal for connecting the cover to the second circuit board.

The EMI shielding terminal may include an upper terminal portion connected to the cover can or the cover and a lower terminal portion connected to the second circuit board and the upper terminal portion. The EMI shielding terminal may further include a middle terminal portion located between the upper terminal portion and the lower terminal portion for interconnecting the upper terminal portion and the lower terminal portion.

The upper terminal portion may be connected to the cover can or the cover by soldering, conductive epoxy, or welding, and the lower terminal portion may be connected to the second circuit board by soldering, conductive epoxy, or welding.

In another embodiment, a camera module includes the image sensor, the second printed circuit board having the image sensor mounted thereon, and the lens moving apparatus with the above-stated construction.

In a further embodiment, a camera module includes a bobbin equipped with at least one lens, a position sensing unit for sensing the position of the bobbin in an optical axis direction and outputting the sensed position of the bobbin as position information, a first coil and a driving magnet arranged opposite to each other for moving the bobbin in an optical axis direction of the lens, and a focus controller for controlling interaction between the first coil and the driving magnet based on subject information and the position information to move the bobbin in a first direction parallel to the optical axis by a first movement amount, thereby performing an auto focusing function.

The subject information may include at least one selected from among the distance between a subject and the at least one lens, the position of the subject, and the phase of the subject.

The focus controller may include an information receiving unit for receiving the subject information, a bobbin position retrieval unit for retrieving the position of the bobbin having a proper focus corresponding to the received subject information, and a movement amount adjustment unit for moving the bobbin to the retrieved position by the first movement amount.

The bobbin position retrieval unit may include a lookup table for storing the position of the bobbin having a proper focus corresponding to the subject information in a mapped state and a data extraction unit for extracting the position of the bobbin having the proper focus corresponding to the received subject information from the lookup table

The lookup table may code and store the position of the bobbin.

The lookup table may be created using the position sensing unit before the bobbin is moved by the first movement amount.

After moving the bobbin by the first movement amount, the focus controller may move the bobbin within a range of a second movement amount which is less than the first movement amount to find a final focal position of the bobbin having the largest modulation transfer function value.

The focus controller may move the bobbin for a predetermined period or a predetermined number of times so as to find the largest modulation transfer function value

The camera module may further include a second coil located opposite to the driving magnet, and the bobbin may be moved in second and third directions perpendicular to the first direction by interaction between the second coil and the driving magnet.

The camera module may further include an image sensor for outputting the subject information to the focus controller.

