A device for detecting image information includes an intermediate transfer
member configured to hold a pattern image; a detecting unit configured to
optically detect the pattern image; a secondary transfer unit configured
to contact with and separate from the intermediate transfer member; and a
control unit that controls the secondary transfer unit in such a manner
that the secondary transfer unit does not contact the intermediate
transfer member while the detecting unit is detecting the pattern image,
and that controls the secondary transfer unit in such a manner that the
secondary transfer unit contacts the intermediate transfer member after
the detecting unit finishes detection of the pattern image.