Epson 2200 Service Manual - Page 43

EPSON Stylus PHOTO 2100/2200 2.2.1.3 Sequence Used for PW Detection The PW detector on the Carriage unit bottom performs the following sequence. ! Off-paper printing prevention control Before start of printing (immediately after the end of paper locating) or during printing, whether paper is present or not is detected to prevent off-paper printing onto the Paper guide. (Applied to only the left or right end of the paper) If the sent data has the paper size that is larger than the fed paper size, trimming is executed according to the paper size detected by the PW sensor, and frame printing is performed (frame width 2mm). Reversely, if the received data has the paper size that is smaller than the fed paper size, frame printing is also performed. This feature is designed to prevent off-paper printing onto the Paper guide by frameless printing performed in a wrong using method. However, in the fast mode for plain paper or postcards, paper width detection is not executed to improve the throughput. When the above using method is performed, the specifications of trimming and frame printing are not applied. ! CD-R center detection control (Only for Stylus PHOTO 2100) When printing is not being performed, the PW detector is used to detect the center of CD-R. Refer to 2.2.3.6 "CD-R Printing Mechanism (Only for Stylus PHOTO 2100)" for details. ! Board paper/roll paper leading edge detection control Control exercised to detect the user-preset board paper leading edge, or control carried out to detect the roll paper edge. Therefore, the PW sensor does not detect a paper leading edge at the time of ASF cut sheet feeding. Revision B ! Off-range restriction control At the time of frameless printing, a paper leading edge is detected using the PW detector to restrict the frameless off-range amount. " Auto sheet feeder complete frameless mode In the complete frameless mode, control is performed to print the print data 3mm larger at top, 5mm larger at bottom, and 2.5mm lager at left and right than the detected paper size. (3mm larger at top, 5mm larger at bottom, and 3.5mm lager at left and right for A3 or A3+ size) " Roll paper mode In the left and right frameless mode, control is performed to print the print data 2.5mm lager at left and right than the detected paper size. (3mm larger at top, 5mm larger at bottom, and 2.5mm lager at left and right when the fixed-format mode is selected) ! PW sensor dark voltage (VH) measurement PW sensor dark voltage (VH) measurement is performed at the following timings and locations and used to calculate the threshold value of whether paper is present or not. " Cut sheets, Roll paper The dark voltage is measured and updated at every power-on, and the threshold value (VS) is calculated and saved in the EPROM 76 area as a PW detection level. The dark voltage is measured at 3poinst on the left flat portion of the the Paper Guide Front. If the PW level measured in the Papaer width measuerment sequence is less than the PW detection level stored in the EEPROM, it means the sensor is detecting the paper. " CD-R tray (Only for Stylus PHOTO 2100) When a CD-R is used, the dark voltage is measured on the CD-R tray, and the threshold valve (VS) is then calculated and saved in the EPROM 76 area as a PW detection level. If the PW sensor level measured in the CD-R HP detection sequence & CD-R center position detection sequence is less than the PW detection level stored in the EEPROM, it means the sensor is detecting the HP of the CD-R tray and the CD-R on the tray. Every paper or CD-R tray is loaded, the voltage measured on the Paper or CD-R tray is stored in the EEPROM BB area as a white level. OPERATING PRINCIPLES Printer Mechanism 43