Canon i-SENSYS MF229dw Service Manual

Canon i-SENSYS MF229dw Service Manual Manual pdf 49 page image

22 2-252-25Technical Overview > Fixing System > Other Functions > Throughput Down ControlTechnical Overview > Fixing System > Other Functions > Throughput Down Control4) Abnormal low temperature detectionAfter temperature of the Fixing Assembly exceeds 50 deg C at least once, monitortemperature of the Thermistor for every 5 msec. It is judged as heater abnormal lowtemperature when the following condition is detected 240 consecutive times: thetemperature is 100 deg C or lower while paper is at fixing nip, or it is 55 deg C or lowerduring paper interval temperature control or at cleaning mode.5) Thermistor open detectionAfter temperature of the Fixing Assembly exceeds 50 deg C, monitor temperature of theThermistor for every 5 msec. When it is detected that the temperature is lower than 20 degC for 6 consecutive times, it is judged as Thermistor open failure.6)Startup failure detectionIf temperature of the Fixing Assembly is 100 deg C or higher when the machine becomes inpickup enabled state after entering fixing low voltage inlet sequence, it is judged as startupfailure.7) Thermistor low temperature detection 2)Temperature of the Thermistor is monitored for every 200 msec when paper is at fixingnip during the Fixing Assembly control. When the temperature is lower than 135 deg C(120 deg C), increase the value of low temperature detection counter by 1 (+1). When itis 135 deg C (120 deg C) or higher, decrease the value by 1 (-1). When the value of lowtemperature counter becomes +150, it is judged as Thermistor low temperature failure. Thedefault and minimum value of low temperature detection counter is 0.8)Frequency detection circuit error (230V models only)When frequency measurement is not completed within 3255 msec after the completion ofprevious frequency measurement, it is judged as frequency detection circuit error.● Processing after failure detectionIf the Main Motor is in driving state when Fixing Assembly failure is detected, rotation of themotor is maintained for 300 msec after the machine moves in Fixing Assembly failure state.Then, drive systems (Main Motor system, Laser/Scanner system, high voltage system, andfixing system) are stopped immediately and the machine moves in failure state.If the Main Motor is not in driving state, drive systems are stopped immediately and themachine moves in failure state.Other Functions■ Throughput Down ControlThis machine performs the throughput down control that extends the paper interval and lowerthe printing speed to prevent the edge of the fixing heater from overheating at continuousprinting of small paper (the paper with narrow width) and to prevent the fixing heater unit fromoverheating at high-volume continuous printing.An extended paper interval lowers the fixing heater temperature between the papers,preventing the edge of the roller of fixing assembly and the delivery unit from overheating.This control has the following 6 modes and the operation sequence differs depending on eachmodes.Paper SizePaper Type Large-sized Small-sized orNarrow Long and Narrow 16KLength: 271 mm ormoreWidth: 190 mm ormoreLength: less than271 mm(Width: less than190 mm)Length: lessthan 313 mmWidth: lessthan 190 mmLength: 313mm or moreWidth: lessthan 190 mmLength:270 +/- 15mmPlain Paper 25 (Full speed)-> 12 (Half speed) *1 (2) 3 ppm(half speed)1 ppm(half speed) *2 (5)Plain Paper L 25 (Full speed)-> 12 (Half speed) *1 (2) 3 ppm(half speed)1 ppm(half speed) *2 (5)Heavy Paper - (1) 3 ppm(half speed)1 ppm(half speed) *2 (6)Rough Paper1 - (1) 3 ppm(half speed)1 ppm(half speed) *2 (6)Rough Paper2 - (1) 3 ppm(half speed)1 ppm(half speed) *2 (6)Label Paper - - - - -Transparency - - - - -Postcard (4) (4) - - -Envelope - (1) - - -*1 : When the number of fed paper reaches 270 after starting from Cold state, the speedchanges from full speed to half speed, and the throughput changes from 25ppm to 12ppm.The number of fed paper at which the throughput changes from full speed to half speedmay vary according to temperature control of the Fixing Assembly.*2 : Measures against wrinkle and curl.T-2-9