Transient tone fluctuations after switch-on have been observed in color electrophotographic (EP) printers. This paper presents preliminary results of using regression analysis to model the behaviors and to identify the key contributing factors. A pilot study using off-the-shelf color EP printers revealed systematic deviation in tone reproduction during the switch-on transient under certain environmental conditions. It can be shown that the tone values reproduced during the switch-on transient are statistically different from the tone values reproduced during continuous printing after the switch-on transient has ended. In the mid-tone areas, the tone values of the first page printed after switch-on and the mean tone values of the pages printed during continuous printing can differ by four ΔE76 units under low temperature and humidity conditions. Analyses of experimental data showed that number of pages printed after switch-on and halftone levels are statistically significant factors in modeling tone deviation. The resulting regression model can accurately predict the switch-on transient deviation to within one ΔE76 unit based on cross-validation.
Yan-Fu Kuo, Chao-Lung Yang, George T.-C. Chiu, Yuehwern Yih, Jan P. Allebach, Carl D. Geleynse, "Modeling of Tone Deviation during Switch-on Transient for Color Electrophotography" in Proc. IS&T Int'l Conf. on Digital Printing Technologies and Digital Fabrication (NIP25), 2009, pp 703 - 706, https://doi.org/10.2352/ISSN.2169-4451.2009.25.1.art00081_2