Optical reader having partial frame operating mode

An apparatus for decoding information from a decodable symbol, the apparatus comprising:

• an imaging assembly having a 2D image sensor and optics focusing an image onto said 2D image sensor;
• a housing adapted to be grasped by a human hand;
• wherein said apparatus is configured to operate in a first operating mode in which said apparatus operates the 2D image sensor to capture a partial frame of image data representing at least a portion of the decodable symbol and corresponding to a first set of pixels of said 2D image sensor, wherein said apparatus when operating in said first operating mode avoids obtaining electrical signals representing light intensity at each pixel of said image sensor;
• wherein said apparatus is configured to process the partial frame of image data corresponding to said first set of pixels to attempt to decode therefrom information encoded by the decodable symbol;
• and
• wherein said apparatus is further configured to operate in a second operating mode in which said apparatus operates the 2D image sensor to capture a frame of image data representing at least a portion of the decodable symbol and corresponding to a second set of pixels of said 2D image sensor, the second set of pixels being different from said first set;
• and
• wherein said apparatus is configured to switch out of said first operating mode and into said second operating mode on the condition that apparatus fails to decode information encoded by said decodable symbol when operating in said first operating mode.