Prism motor, method for detecting a rotation angle of a prism motor, and photographing module

A method for detecting a rotation angle of a prism motor, applied to a prism motor comprising:

• a prism base;
• a prism carrier, spaced apart from the prism base, wherein the prism carrier is rotatable relative to the prism base;
• a first electrode plate, located on a surface of the prism base;
• a second electrode plate, located on a surface of the prism carrier and disposed opposite to the first electrode plate, wherein the first electrode plate and the second electrode plate form a capacitor, and in a case where the prism carrier rotates in one direction about a first rotation axis, either an opposing area between the first electrode plate and the second electrode plate increases while a spacing between the first electrode plate and the second electrode plate decreases, or an opposing area between the first electrode plate and the second electrode plate decreases while a spacing between the first electrode plate and the second electrode plate increases;
• and
• a processing unit, configured to determine a rotation angle of the prism carrier based on a capacitance signal generated by the capacitor formed by the first electrode plate and the second electrode plate;
• the method comprising:
• determining an initial capacitance signal generated by the capacitor formed by the first electrode plate and the second electrode plate at an initial position of the prism carrier;
• determining a current capacitance signal upon a change in capacitance signal generated by the capacitor formed by the first electrode plate and the second electrode plate;
• and
• determining a rotation angle of the prism carrier based on a difference between the current capacitance signal and the initial capacitance signal.

A photographing module, comprising:

• a prism motor;
• a lens;
• and
• a photosensitive chip, wherein incident light entering the photographing module is reflected by the prism motor, passes through the lens, and reaches the photosensitive chip;
• wherein the prism motor includes:
• a prism base;
• a prism carrier, spaced apart from the prism base, wherein the prism carrier is rotatable relative to the prism base;
• a first electrode plate, located on a surface of the prism base;
• a second electrode plate, located on a surface of the prism carrier and disposed opposite to the first electrode plate, wherein the first electrode plate and the second electrode plate form a capacitor, and in a case where the prism carrier rotates in one direction about a first rotation axis, either an opposing area between the first electrode plate and the second electrode plate increases while a spacing between the first electrode plate and the second electrode plate decreases, or an opposing area between the first electrode plate and the second electrode plate decreases while a spacing between the first electrode plate and the second electrode plate increases;
• and
• a processing unit, configured to determine a rotation angle of the prism carrier based on a capacitance signal generated by the capacitor formed by the first electrode plate and the second electrode plate.