HP M750 series

Image stabilization control
The image stabilization control reduces the fluctuations in image density caused by environmental changes
or deterioration of the photosensitive drums or toner. The two kinds of image stabilization controls are
image density control (DMAX) and image halftone control (DHALF).
Image density control (DMAX)
The image density control calibrates each high-voltage bias to stabilize the image density variation caused
by the deterioration of the photosensitive drum or toner. The DC controller commands the formatter to
control the image density under the following conditions:
●
The detected temperature of the fuser is a specified degree or lower when the product is turned on
●
The product is turned on, or the door is closed, and also whenever a specified number of pages have
been printed after replacing any one of the cartridges
●
The product is turned, on or the door is closed, after replacing the ITB unit or the laser scanner unit
●
A specified number of pages have been printed
●
After a specified period of time from the previous image density control
●
The environment is changed for a specified condition after the previous image density control
Image halftone control (DHALF)
The image halftone control is performed by the formatter to calibrate the halftone. The DC controller
measures the halftone pattern according to a command from the formatter. Accordingly, the formatter
calibrates the halftone. The DC controller controls the image halftone under the following conditions:
●
The image density control is completed
●
The formatter sends a command
42 Chapter 1 Theory of operation ENWW