Patent ID: 8228377
Filing Date: 2012-07-24
Classification: H04N

Abstract:
1. A camera comprising: a camera housing; a camera lens rotatably disposed in the camera housing and disposed to rotate with respect to the camera housing, a camera support coupled to the camera housing, wherein the camera housing is rotatably disposed on the camera support; a DC motor having a plurality of rotors and coupled with the camera lens to pan the camera lens along with the camera housing relative to the camera support or tilt the camera lens relative to the camera housing; a sensor configured to track a subject; a controller coupled with the DC motor to control the DC motor and to the sensor to receive position information of the subject being tracked; a back EMF encoder coupled with the DC motor and configured to detect pulses from rotations of the rotors; and a pulse counter coupled to the back EMF encoder and configured to count the pulses detected by the back EMF encoder and determine from the count a number of rotations of the rotors; wherein the controller is configured to control movement of the DC motor based on the position information received from the sensor, the position information including a target position at which the subject stops, and the number of rotations; and wherein the controller is configured to reverse a polarity of the DC motor before the camera lens reaches the target position to slow movement of the camera lens and avoid overshooting the target position.