Patent ID: 7471329
Filing Date: 2008-12-30
Classification: H04N

Abstract:
1. A digital camera comprising: (a) an imaging photography unit comprising a focusing lens, a focusing lens driving unit, and an image sensing unit with a light-receiving surface divided into a chromatic sensing element and an achromatic sensing element, the image sensing unit outputting a digital image signal; (b) a digital signal processor that processes the digital image signal; (c) a data storage unit; (d) an automatic focusing shutter that outputs an automatic focusing indication signal; (e) a brightness comparator in communication with an output of the image sensing unit to receive the digital image signal, the brightness comparator, in response to the automatic focusing indication signal, recognizing a sensed brightness of the digital image signal, comparing the sensed brightness of the digital image signal with a predetermined reference brightness and outputting a brightness comparison result; (f) a selector in communication with the brightness comparator and the output of the image sensing unit, the selector outputting, in response to the brightness comparison result, a chromatic image signal relative to the chromatic sensing element if the brightness of the digital image signal is greater than the predetermined reference brightness or an achromatic image signal relative to the achromatic sensing element if the brightness of the digital image signal is equal to or smaller than the predetermined reference brightness; and (g) a focus signal generator in communication with an output of the selector, the focus signal generator analyzing high frequency components of the chromatic or achromatic image signal from the selector, calculating a focal value according to said high frequency components of the chromatic or achromatic image signal, and outputting the focus signal to the focusing lens driving unit to move the focusing lens to a focal location.