EPSON Stylus Color 440/640/740 - el Museo de los 8 Bits

EPSON Stylus Color 440/640/740Revision ASee Figure 2-6 which shows the carriage mechanism.Paper Feed MotorCarriage home position SensorPF Roller Timing BeltCarriage UnitEject Roller Paper guide(Front)Front SideCarriage MotorRear SideParallelismAdjust LeverFixing Bushaccording to the printing result or any other environmental conditionssuch as paper curl.Carriage lock mechanism is to prevent the carriage from being left at anuncapped position for a long time because of vibration during the printertransport or mishandling by the users. If the carriage is left uncapped forlong time, ink on the print head surface gradually becomes thick. As aresult, the nozzle will be unable to discharge ink.To make matters worse, the holes (crater) of nozzle may be completelyclogged by the thick ink and it may not be able to return to the normalcondition just by cleaning operation. In order to prevent this, printergoes to carriage lock state at the following conditions. (See the followingpage.)After Power OFF operation:If the power is turned off on the way of printing or any otherperformance, carriage lock will be performed in the end aftercompleting initialize operation.CarriageGuide ShaftFigure 2-6. Carriage Mechanism (Top view)The printhead, a core of the printing mechanism, is stored in thecarriage unit. When the adjustment lever is moved up and down, thisprinthead maintains the printhead tilt in a flexible and adjustablestructure, using a tilt adjustment mechanism. Also, the parallelismadjustment lever, mounted on the left and right sides of the carriageguide shaft, adjusts parallelism between the platen and shaft when theshaft is installed to the printer mechanism. After this adjustment iscompleted, moving PG adjustment lever changes space between theplaten surface and the print head surface to one of two possibilities:either 1.04 mm or 1.74mm. It is possible to vary the space betweenplaten surface and print head by rotating the shafts of the carriage guideshaft which itself is decentralized, with the operation of PG lever. This isthe mechanism that the user can use to adjust the appropriate PG valueAfter power ON operation:After power is turned on and automatic P-On Cleaning is performed,then carriage lock will be performed. P-On Cleaning is an automatichead cleaning that is performed when the power is turned on. Thetimer IC always calculates printer’s power OFF time by the power oflithium battery mounted on the C206 Main-B/C255/C256/C257 Mainboard. P-on cleaning function automatically selects the cleaninglevel according to the time which the printer is not inused.After Eject the paper:After Load/Eject button is pressed and the paper is ejected, if thedata is not input, the printer performs carriage lock and goes tostandby state. However, if the paper is loaded to the printer insideby Load/Eject button, the printer does not perform carriage lockoperation.Chapter 2 Operating Principles 48