Camera module actuator movement sensing element and camera module flexible circuit board including same
The present invention relates to a camera module actuator movement sensing element required for camera shake correction, and a camera module flexible circuit board including the same. On the camera module flexible circuit board, there are mounted: a plurality of actuator movement sensing elements for sensing each of the movement distances of an actuator in the x-axis and y-axis directions perpendicular to the optical-axis (z-axis) direction of the actuator to which a lens assembly is coupled, and transmitting the same by a method using a two-wire interface; and an OIS controller IC for performing camera shake correction by receiving, from the plurality of actuator movement sensing elements, a feedback of the movement distances of the actuator by the method using a two-wire interface, wherein: the plurality of actuator movement sensing elements share a common serial data pin and a common serial clock pin with each other, and the common serial data pine and the common serial clock pin are connected to a serial data pin and a serial clock pin of the OIS controller IC, respectively; and the plurality of actuator movement sensing elements share a common power pin and a common ground pin with each other, or share only a common power pin or a common ground pin with each other.
1. A camera module actuator movement sensing element comprising:
a Hall sensor configured to sense a movement distance of an actuator in an x-axis or y-axis direction perpendicular to an optical axis (z-axis) direction of the actuator to which a lens assembly is coupled;
a first signal preprocessor configured to amplify an actuator movement distance sensing signal output from the Hall sensor, then remove noise, and then convert into actuator movement distance sensing data in a digital form;
an interface configured to transmit the actuator movement distance sensing data to an optical image stabilization (OIS) controller, wherein the actuator movement distance sensing data is transmitted in a two-wire interface method;
a temperature sensing sensor configured to sense an ambient temperature of the actuator;
a second signal preprocessor configured to amplify a temperature sensing signal output from the temperature sensing sensor and then remove noise; and
a multiplexer configured to selectively output one of the actuator movement distance sensing signal from which noise is removed or the temperature sensing signal from which noise is removed to a digital conversion part of the first signal preprocessor according to a control period.
2. The camera module actuator movement sensing element of claim 1 , wherein the Hall sensor, the first signal preprocessor, the interface, the temperature sensing sensor, the second signal preprocessor, and the multiplexer are packaged in a one-chip integrated circuit (IC).
3. The camera module actuator movement sensing element of claim 1 , further comprising:
an actuator driver configured to generate an actuator drive signal according to actuator drive control data transmitted from the OIS controller through the interface and output the actuator drive signal to the actuator.
4. The camera module actuator movement sensing element of claim 3 , wherein the actuator driver is packaged in a one-chip integrated circuit (IC) together with the Hall sensor, the first signal preprocessor, and the interface or packaged in a one-chip IC together with the Hall sensor, the first signal preprocessor, the interface, the temperature sensing sensor, the second signal preprocessor, and the multiplexer.
5. A camera module flexible circuit board comprising:
a plurality of actuator movement sensing elements configured to sense movement distances of an actuator in x-axis and y-axis directions perpendicular to an optical axis (z-axis) direction of the actuator to which a lens assembly is coupled and transmit the sensed movement distances in a two-wire interface method; and
an optical image stabilization (OIS) controller integrated circuit (IC) configured to correct hand shake by receiving feedback of the movement distances of the actuator from the plurality of actuator movement sensing elements in the two-wire interface method,
wherein a serial data pin and a serial clock pin of each of the plurality of actuator movement sensing elements are shared to be connected to a serial data pin and a serial clock pin of the OIS controller IC, and a power pin and a ground pin of each of the plurality of actuator movement sensing elements are shared, or only either the power pin or the ground pin is shared,
wherein each of the plurality of actuator movement sensing elements includes,
a Hall sensor configured to sense the movement distance of the actuator in the x-axis or y-axis direction perpendicular to the optical axis (z-axis) direction of the actuator to which the lens assembly is coupled,
a first signal preprocessor configured to amplify an actuator movement distance sensing signal output from the Hall sensor, then remove noise, and then convert into actuator movement distance sensing data in a digital form, and
an interface configured to transmit the actuator movement distance sensing data to the OIS controller IC in a two-wire interface method, and
wherein the camera module flexible circuit board further includes,
a temperature sensing sensor configured to sense an ambient temperature of the actuator;
a second signal preprocessor configured to amplify a temperature sensing signal output from the temperature sensing sensor and then remove noise; and
a multiplexer configured to selectively output one of the actuator movement distance sensing signal from which noise is removed or the temperature sensing signal from which noise is removed to a digital conversion part of the first signal preprocessor according to a control period.
6. The camera module flexible circuit board of claim 5 , wherein the Hall sensor, the first signal preprocessor, the interface, the temperature sensing sensor, the second signal preprocessor, and the multiplexer are packaged in a one-chip IC.
7. The camera module flexible circuit board of claim 5 , further comprising:
an actuator driver configured to generate an actuator drive signal according to actuator drive control data transmitted from the OIS controller IC through the interface and output the actuator drive signal to the actuator.
8. The camera module flexible circuit board of claim 7 , wherein the actuator driver is packaged in a one-chip IC together with the Hall sensor, the first signal preprocessor, and the interface or packaged in a one-chip IC together with the Hall sensor, the first signal preprocessor, the interface, the temperature sensing sensor, the second signal preprocessor, and the multiplexer.