Lens drive device, camera module, and camera mount device

A lens driving device, comprising:

• an auto-focusing coil to be disposed at a periphery of a lens part;
• an auto-focusing magnet to be disposed to be radially spaced apart from the auto-focusing coil;
• and
• a yoke configured to form a magnetic circuit with the auto-focusing magnet, the lens driving device being configured to automatically perform focusing by moving, with respect to an autofocus fixing part including the auto-focusing magnet and the yoke, an autofocus movable part including the auto-focusing coil in an optical-axis direction by utilizing a driving force of a voice coil motor composed of the auto-focusing coil and the auto-focusing magnet,
• wherein the auto-focusing coil is an elliptic flat coil including a first linear portion and a second linear portion, and the auto-focusing coil is disposed such that the first linear portion is on a light reception side in the optical-axis direction and the second linear portion is on an image formation side in the optical-axis direction,
• wherein the auto-focusing magnet is composed of a first magnet and a second magnet, the auto-focusing magnet has two poles on each side, and the auto-focusing magnet is disposed such that the first magnet faces the first linear portion and the second magnet faces the second linear portion,
• wherein the yoke is disposed to cover a surface of the first magnet on the light reception side in the optical-axis direction,
• wherein an area of a surface of the first magnet facing the first linear portion is greater than an area of a surface of the second magnet facing the second linear portion, and
• wherein a magnetic flux crossing the first linear portion is greater than a magnetic flux crossing the second linear portion throughout a range of movement of the autofocus movable part.