Patent ID: 8520250

Claim:
An image reading apparatus: a reading image unit configured to read an image data of a document that is divided into plural reading sections in one page, each of plural reading section including plural lines; a memory configured to write the image data obtained by the reading image unit in a space region of the memory; a memory managing unit configured to determine whether the space region larger than a predetermined size exists in the memory, the predetermined size corresponding to a memory size available to store the image data of one reading section; and a reading operation control unit configured to manage reading image operation and interruption of the reading image unit for one of the reading sections of the document; wherein the reading operation control unit includes a reading section counter configured to hold a counter value indicating how many reading sections can be read and stored in the memory further, and when the reading image unit finishes reading the image data of one of the reading section, the reading operation control unit determines whether to continue to read the image data based on the counter value of the reading section counter, wherein if the reading section counter indicates the counter value equal to or greater than 1, the reading operation control unit causes the reading image unit to read another image data of following one of the reading sections of the document, and if the reading section counter indicates the counter value of 0, the reading operation control unit causes the reading image unit to interrupt reading the image data, and when counter value changes equal to or greater than 1, the reading operation control unit causes the reading image unit to restart reading the image data, the image reading apparatus further comprising a reading lines number setting unit configured to determine a number of the plural lines included in the one reading section of the plural reading sections is fixed or not, and, if the number of plural lines is fixed and the fixed number of the plural lines causes a problem, the reading lines number setting unit establishes a proper number of plural lines included in one reading section of the plural reading sections based on the size of the document, a reading resolution or an amount data per line to be written in the memory, wherein the reading section including the plural lines correspond to an incremental or decremental unit of the reading section counter.