In a toner image forming apparatus, a contact member for pressing a work
piece at a pressing position against a toner image on a movable transfer
member so that the toner image is transferred from the transfer member
onto the work piece is pressed against the transfer member while a test
pattern toner image which is prevented from being transferred onto the
work piece moves from a transfer position at which the toner image and the
test pattern toner image are transferred onto the transfer member and a
detecting position at which the test pattern toner image is detected to
obtain a difference between the test pattern toner image on the transfer
member and a desired test pattern image.
