Patent ID: 8760741
Filing Date: 2014-06-24
Classification: H04N

Abstract:
1. An image scanning device comprising: an image sensor including an array of a plurality of light receiving elements; a light source for shining light upon a scanning object; a lens unit for guiding reflected light from the scanning object to the image sensor and having a joined plurality of rod lens arrays, in which rod lenses are arrayed; a correction unit for correcting pixel values of pixels corresponding to a position of a joint between the rod lens arrays in image data generated based on output values from the light receiving elements of the image sensor; and a storage unit for storing data, wherein, based on the size of the output values from the light receiving elements, the correction unit performs quantization for converting the output values into pixel values falling in a range between a black reference value and a white reference value, generates digital image data from the output of the image sensor, and corrects the black reference value of light receiving elements subject to correction, which are those light receiving elements corresponding to the positions of joints between the rod lens arrays, and there is determined a ratio between the second output value from the light receiving elements subject to correction when a pre-prepared gray or colored correction scanning object of a uniform color intensity is scanned and a comparison value based on the second output value from a light receiving element other than the light receiving elements subject to correction; the storage unit stores the position and ratio of the light receiving elements subject to correction; and the correction unit determines the black reference value for each of the light receiving elements based on output values from each of the light receiving elements when the light source is unlit, and performs correction in which the black reference value of the light receiving elements subject to correction is multiplied by or divided by the ratio, and the black reference value is reduced.