Camera actuator and camera module including same

A lens driving device, comprising:

• a housing;
• a fixed part disposed in the housing and including a first lens part;
• a moving part moving relative to the fixed part and including a lens;
• a driving part for driving the moving part in an optical axis direction;
• and
• a sensing part for sensing a position of the moving part;
• wherein the moving part includes:
• a magnet part including:
• a magnet scaler having a structure in which a plurality of magnets having different polarities are sequentially disposed in the optical axis direction;
• and
• a reference magnet including a single-pole magnet in which a N-pole and a S-pole are disposed in a direction perpendicular to the optical axis direction, and
• wherein the sensing part acquires each of a first sensing signal corresponding to a magnetic force of the reference magnet that changes according to a movement of the moving part and a second sensing signal corresponding to a magnetic force of the magnet scaler that changes according to the movement of the moving part,
• wherein the magnet scaler and the reference magnet move together with the lens,
• wherein the driving part moves the moving part to an initial position using the first sensing signal, and moves the moving part to a target position using the second sensing signal,
• wherein the first sensing signal has a maximum voltage value when the moving part moves to the initial position,
• wherein the housing includes a hole in which at least a portion of the sensing part is disposed,
• wherein the magnet part and the sensing part overlaps to each other in the direction perpendicular to the optical axis direction,
• wherein the moving part further includes:
• a first lens barrel disposed to be spaced apart from the fixed part in the optical axis direction in the housing;
• and
• a second lens barrel disposed to be spaced apart from the moving part in the optical axis direction in the housing,
• wherein the driving part includes:
• a first driving part coupled to the first lens barrel in the housing and driving the first lens barrel in the optical axis direction;
• and
• a second driving part coupled to the second lens barrel in the housing and driving the second lens barrel in the optical axis direction;
• wherein the magnet part further includes:
• a first magnet part including a first magnet scaler and a first reference magnet disposed on one surface of the first lens barrel;
• and
• a second magnet part including a second magnet scaler and a second reference magnet disposed on an other surface of the second lens barrel,
• wherein the sensing part includes:
• a first sensing part disposed adjacent to the first magnet part;
• and
• a second sensing part disposed adjacent to the second magnet part,
• wherein the first lens barrel includes:
• a first barrel part including a second lens part;
• a first guide part extending outwardly from the first barrel part;
• and
• a first elastic part connected to the first driving part,
• wherein the second lens barrel includes:
• a second barrel part including a third lens part;
• a second guide part extending outwardly from the second barrel part;
• and
• a second elastic part connected to the second driving part,
• wherein the first driving part includes:
• a first piezoelectric device disposed in the housing;
• and
• a first extension bar extending in the optical axis direction from the first piezoelectric device,
• wherein the second driving part includes:
• a second piezoelectric device disposed in the housing;
• and
• a second extension bar extending in the optical axis direction from the second piezoelectric device,
• wherein one region of the first extension bar is connected to the first elastic part, and
• wherein one region of the second extension bar is connected to the second elastic part.