Patent ID: 7161127
Filing Date: 2007-01-09
Classification: G02B

Abstract:
1. An automatic focusing apparatus comprising: a light source for applying a light to an observation target; a photographing unit for photographing a transmitted light generated by the light being applied to the observation target from the light source and outputting the photographed light as image data; an index value operation unit for obtaining background color information from the image data outputted from the photographing unit and obtaining an index value indicating focus information for the observation target on the basis of the background color information; and a focus controller for controlling a focus of the photographing unit so as to obtain an optimal focus position for the observation target on the basis of the index value, wherein the index value operation unit comprises: a background color operation unit for obtaining the background color information from the image data; a threshold value operation unit for obtaining a threshold value for the image data on the basis of the background color information; a clip unit for subjecting the image data to clipping processing using the threshold value; a high-pass filter for extracting high frequency components of the image data from an output signal of the clip unit; and an operation unit for obtaining the index value on the basis of an output signal of the high-pass filter.