Patent ID: 8325383

Claim:
An image reading device for scanning a document by causing a relative movement between the document, and a given number (i) of pixel rows, where i is an integer of 2 or larger, in a vertical direction orthogonal to a horizontal direction, each of the pixel rows being formed by arranging a certain number of pixels in the horizontal direction, and each of the pixel rows having a pitch in the vertical direction equal to or larger than (i+1)/i of a size of an opening of the pixel in the vertical direction, the image reading device comprising: a readout circuit, provided in common with respect to the pixel rows, for reading out image data; a resolution setter for setting a vertical resolution in scanning the document; and a controlling section for allocating a predetermined H period as a readout period of each of the pixel rows so that each of the pixel rows reads an identical line of the document, depending on the vertical resolution set by the resolution setter, assuming that a period when a relative movement of each of the pixel rows by a distance equal to the size of the opening of the pixel in the vertical direction is made is defined as one frame period, and the one frame period is divided into the given number (i) of H periods.