Optical navigation scheme capable of saving more power based on variable frame rate as well as outputting enough displacement/position data to achieve precise motion tracking

An optical sensor device, to be used in an optical navigation device which is used to communicate with a remote computer device based on a transmission interface, comprising:

• a sensing unit, for receiving and sensing reflected light from a surface on which the optical navigation device moves with a specific flash rate which is lower than a specific reporting rate of the transmission interface;
• and
• a processing circuit, coupled to the light emitting unit, for capturing image frames with a specific frame rate to generate actual displacement data and generating predicted displacement data to form resultant displacement data which are to be outputted from the optical navigation device to the remote computer device;
• wherein the processing circuit is arranged to generate and insert a set of predicted displacement data between at least two consecutive sets of actual displacement data generated due to the image frames captured by the optical sensor device.

A method applied into an optical navigation device, used to communicate with a remote computer device based on a transmission interface, and the method comprises:

• capturing image frames according to a specific frame rate to obtain actual displacement data corresponding to the captured image frames, the specific frame rate being lower than a specific reporting rate specified by the transmission interface;
• generating predicted displacement data based on the actual displacement data;
• using the actual displacement data and the predicted displacement data to form resultant displacement data which is to be outputted;
• and
• outputting the resultant displacement data to the remote computer device based on the specific reporting rate specified by the transmission interface;
• wherein the step of generating the predicted displacement data comprises:
• generating and inserting a set of predicted displacement data between at least two consecutive sets of actual displacement data generated due to the image frames captured by the optical sensor device.