Image reader for use in an image forming apparatus, and contamination check method of guide film for the same

An image forming apparatus including an image reading table and comprising:

• a document glass installed on an upper side of the image reading table, to support a document;
• an image reading sensor installed under the document glass, to perform an image reading operation;
• a cover to selectively cover the document glass;
• an automatic document feeder (ADF) to feed a document along an image reading path, past the image reading sensor;
• a document discharging plate to support a document discharged from the ADF;
• first and second guide members installed in the ADF, to guide a document along the image reading path, the first and second guide members being installed at an interval with respect to the document glass, such that a document is exposed to the image reading sensor through the interval;
• a guide film to cover the interval between the first and second guide members, to guide a document along the image reading path between the first and second guide members;
• and
• an image forming part to form the image on a printable medium.

A method of checking contamination of a guide film of an image reading apparatus performing a scanning operation, comprising:

• obtaining basic scan data by performing the scanning operation through the guide film, when a document is not fed along the guide film and the guide film is not contaminated;
• performing the scanning operation while feeding a document through an automatic document feeder (ADF) past the guide film, while reading an image of the document through the guide film, using an image reading sensor;
• comparing a current number of scanned documents to a predetermined number of scanned documents;
• obtaining measured scan data by performing the image reading operation without feeding a document along the guide film, when the current number of scanned documents is greater than the predetermined number of scanned documents;
• and
• comparing the basic scan data to the measured scan data, to determine whether the guide film is contaminated.

An image reader for use in an image forming apparatus, comprising:

• an image reading table provided with a platen glass;
• an image reading sensor provided under the platen glass, to perform an image reading operation;
• a cover rotatably fixed at a distal end of the image reading table, to selectively cover the platen glass;
• an automatic document feeder (ADF) disposed on the cover, to feed a document along an image reading path, past the image reading sensor;
• a document discharging plate to receive a document discharged from the ADF;
• first and second guide members arranged inside the ADF, to guide a document along the image reading path, the first and second guide members being disposed at the platen glass, so as to form an opening through which a document is exposed to the image reading sensor;
• and
• a guide film to cover the opening, to guide a document along the image reading path, between the first and second guide members.