This invention realizes and provides an image forming apparatus in which
the presence or absence of a toner remaining in a toner storing portion
is judged by a patch detecting method, characterized in that the wrong
detection of the judgment of the presence or absence of the toner can be
prevented and the lowering of image density can be suppressed. In an
image forming apparatus having a first toner supply controller for
controlling the driving time of a toner supplying portion on the basis of
the video count number of the density signal of an image information
signal, and a second toner supply controller for correcting the driving
time of the toner supplying portion determined by the first toner
controller, and designed such that the presence or absence of the toner
remaining in the toner storing portion is judged on the basis of the
density signal of a standard toner image, when the density signal of the
standard toner image is equal to or less than a predetermined value, the
driving time of the toner supplying portion additionally corrected per
image by the second toner supply controller is made longer than when the
density signal of the standard toner image is greater than the
predetermined value.