Piezoelectric actuator, camera module, and portable electronic device having same

A camera module comprising:

• a lens module having an optical axis associated therewith, and
• a piezoelectric actuator for driving the lens module to move, the piezoelectric actuator comprising:
• a fixed barrel, the fixed barrel defining a first receiving cavity;
• a movable barrel received in the first receiving cavity, the movable barrel defining a second receiving cavity receiving the lens module;
• a piezoelectric driving module for driving the movable barrel with the lens module to move relative to the fixed barrel along the optical axis, the piezoelectric driving module comprising a piezoelectric member attached on the sidewall of the fixed barrel, and a friction member attached on the sidewall of the movable barrel, the piezoelectric member being opposite to the friction member;
• a flexible circuit board fixed on an outer surface of the fixed barrel, the flexible circuit board being electrically connected with the piezoelectric member;
• a bracing sheet, the bracing sheet being attached around the flexible circuit board and fixing the piezoelectric member on the fixed barrel, and
• a preloading module arranged between the fixed barrel and the movable barrel, the preloading module being opposite to the piezoelectric driving module for exerting a pressure on the movable barrel, thereby making the friction member resist against the piezoelectric member.

A portable electronic device comprising:

• a main body, and
• a camera module mounted on the main body, the camera module comprising:
• a lens module having an optical axis associated therewith, and
• a piezoelectric actuator for driving the lens module to move, the piezoelectric actuator comprising:
• a fixed barrel, the fixed barrel defining a first receiving cavity passing through two opposite ends thereof;
• a movable barrel received in the first receiving cavity, the movable barrel defining a second receiving cavity passing through two opposite ends thereof for receiving the lens module therein;
• a piezoelectric driving module for driving the movable barrel to move relative to the fixed barrel along the optical axis of the lens module, the piezoelectric driving module comprising a piezoelectric member arranged on a sidewall of the fixed barrel, and a friction member arranged on a sidewall of the movable barrel, the piezoelectric member being opposite to the friction member;
• a flexible circuit board fixed on an outer surface of the fixed barrel, the flexible circuit board being electrically connected with the piezoelectric member;
• a bracing sheet, the bracing sheet being attached around the flexible circuit board and fixing the piezoelectric member on the fixed barrel, and
• a preloading module arranged between the fixed barrel and the movable barrel, the preloading module being opposite to the piezoelectric driving module for exerting a pressure on the movable barrel, thereby making the friction member resist against the piezoelectric member.