Image forming apparatus for adjusting image forming position

An image forming apparatus comprising:

• a printer configured to print an image on a sheet;
• a scanner having a glass plate on which a test chart is to be placed and configured to scan the test chart placed on the glass plate and output a read image regarding the test chart;
• a controller configured to:
• print the test chart using the printer, the test chart including a detection image printed on a detection surface of the sheet, a first mark printed on the detection surface, and a second mark printed on the detection surface, wherein the detection image is used for detecting a deviation of a print position and wherein a print position of the first mark on the sheet is different from a print position of the second mark on the sheet;
• perform a first scan by the scanner to acquire a first read image relating to a first region including a portion of the detection image and the first mark;
• perform a second scan by the scanner to acquire a second read image relating to a second region including another portion of the detection image and the second mark, the second region being different from the first region;
• and
• control the print positions based on the detected deviation of the print positions;
• and
• a display configured to:
• display a screen for notifying a user of a position at which the test chart is to be placed on the glass plate in the first scan;
• display a screen for notifying the user of a position at which the test chart is to be placed on the glass plate in the second scan;
• display a screen for prompting the user to reset the test chart in a case where the first mark is not detected from the first read data;
• and
• display a screen for prompting the user to reset the test chart in a case where the second mark is not detected from the second read data,
• wherein the controller causes the printer to print a third mark and a fourth mark on a surface of the sheet different from the detection surface, a print position of the third mark being different from a print position of the fourth mark,
• wherein a color of the first mark is different from a color of the second mark,
• wherein the color of the first mark is different from a color of the third mark,
• wherein the color of the first mark is different from a color of the fourth mark,
• wherein the color of the second mark is different from the color of the third mark,
• wherein the color of the second mark is different from the color of the fourth mark, and
• wherein the color of the third mark is different from the color of the fourth mark.