A color image forming apparatus includes a first density detecting unit for detecting
a density of a first detection toner image formed on an image bearing member or
a transferring material carrying member, and a second density detecting unit for
detecting a density of a second detection toner image fixed onto a transferring
material, and executes image density control based on a detection result of the
first density detecting unit and a detection result of the second density detecting
unit. A detecting light application position of the first density detecting unit
and a detection light application position of the second density detecting unit
are almost equal relative to a perpendicular direction to a transferring material
conveying direction. It is thereby possible to shorten time required for density
control and to prevent deterioration of density control accuracy caused by a temporal
change and a positional change in the density of a detection toner patch.
