Epson Stylus Cx5500 Block Diagram

Figure 2-14. Pump Mechanism Power Transmission Process

The process of conveying the motive power to the paper eject roller by rotating the pinion of PF motor is shown in figure 2-12. This motive power is conveyed to the Gear C through Gear B. In the figure above, although the lever in order to drive Gear C, carriage lock, head cleaner mechanism is shown separately, it is constructed as one unit. Since the engagement of these two parts depends on the tension of the compression spring, if the lever is burdened, only Gear C and pump roller rotate and no more motive power is conveyed to the lever part.

EPSON Stylus Photo

The table below shows PF/Pump motor rotational direction and pump system operation.

Table 2-11. Relationship Between Pump Motor Rotation and Pump Operation

PF/Pump motor rotational direction

Pump unit operation

Clockwise(CW) forward rotation

1)Released from the pressured pump

2)Head cleaner reset

3)Carriage lock reset

Counterclockwise(CCW) backward rotation

1)Move to the state that pump is pressured

2)Head cleaner set

3)Carriage lock set

The figure below shows the pump operation at clockwise and counterclockwise rotations.

The figure below shows the pump operation at clockwise and counterclockwise rotations.

CCW Rotation

CCW Rotation

Figure 2-15. Pump Roller Rotation and it's Operation

In the ink absorptive operation such as cleaning, flushing initial ink charge except for printing operation, ink in the ink cartridge drains to the waste ink absorber(pad) through the cap by the pump unit drive.

In case of printing and flushing, ink is popped out by the PZT in the print head, but in case of absorptive operation such as cleaning and initial ink charge, ink absorption is performed only by the pump drive without PZT drive after the head surface is adhered to the cap.

The next page explains cap mechanism and relation between printer operation and cap mechanism.

2.1.1.4.2 Cap Mechanism

In the cap mechanism, in order to prevent ink from being viscosity on the head surface, it is controlled that the head surface stays adherent to the rubber frame of the cap surface when the power is off. The absorber is spread in the cap and can hold a certain amount of ink which is absorbed from the head without draining it to the waste ink pad. Also, in the bottom of absorber, there are two valves in order to control adhesion of head and cap surface, and one exits to drain ink to the waste ink pad.

Flag for Carriage

Flag for Carriage

Epson Stylus Photo 900 Ink Pads

Ink Eject Valve

Negative pressure release valve

Valve

Head surface and cap are adhered each other. Actual and false absorptions.

During cleaning, initial ink charge, and right flushing.etc.

Ink Eject Valve

Negative pressure release valve

Valve

Head surface and cap are adhered each other. Actual and false absorptions.

Printer Ink Absorption Pad

Flag forframe

Ink absorption in the cap.

During leftflushing and paper feeding,etc.

Flag forframe

Ink absorption in the cap.

During cleaning, initial ink charge, and right flushing.etc.

During leftflushing and paper feeding,etc.

Figure 2-16. Cap Mechanism Operation Principle

If the carriage is out of HP(in this case, in the printable area or paper feed position), the valves on the cap mechanism stays in the position A in the figure above and are always closed. In this condition, the carriage collides with flag, actual ink absorption and slight ink absorption are performed. Also, by moving the carriage to further right side and colliding the flag for opening the valves with the frame, negative pressure is released in the state that head surface and cap are adhered. This makes it possible for ink in the nozzle to be ready for being ejected from the cap in the stable condition.

2.2 Electrical Circuit Operating Principles_

EPSON Stylus Photo contains the following four electric circuit boards.

■ Head Driver board

C206 PSB/PSE, C209 main board are explained in this section. The head drive board is installed in the head unit the carriage. The figure below shows electric circuit block diagram.

Printer Mechanism

Printer Mechanism

Block Diagram Xyz Drive Mechanism
Figure 2-17. Electric Circuit Block Diagram

2.2.1 C206 PSB/PSE Power Board

C206 PSB/PSE board is a power supply board with a RCC switching regulator, which generates +42VDC for drive part and +5VDC for logic part to drive the printer. The table 2-12 below shows application of voltages generated by C206 PSB/PSE board.

Table 2-12. Application of DC Voltage

Voltages

Application

+42V

■ Print Head Common Voltage

+5V

■ C209 Main control Board logic

■ C209PNL Panel Board

■ Sensors (HP sensor, ASF HP sensor, PE sensor)

The power switch of this printer is in the secondary circuit that allows the PSB/PSE board to continue to supply voltage for both power and logic line for at least 30 seconds until the printhead returns to the capping position even if the printer turned off during printing. This prevents ink leakage or dried print head caused by the print head being left uncapped. The AC voltage from the AC inlet is first input to the filter circuit for higher harmonics absorption and is then input to the rectification and smoothing circuit, converting into DC voltage. This DC voltage is then input to the switching circuit. Along with this switching operation by FET on the primary side, +42V voltage is generated and stabilized on the secondary side, which is then converted into the stable +5V VDC by the chopping regulator IC. Figure 2-18 shows the block diagram of the electrical circuit.

Zener Zd52 Zd86
Figure 2-18. C206 PSB/PSE Board Block Diagram

The operating principles of various circuit and controller circuit in the figure above are described below.

□ +5V Line Over Voltage Protection Circuit:

The output voltage level of +5V is monitored by a Zener diode(ZD53) on the secondary circuit. If the voltage level exceeds 9V, the Switching FET Q1 goes off by the following operation, and no induced electromotive force is generated, and generation of +5V and +42V stops as the result.

■ Zener diode(ZD53) detects the voltage which exceeds +9V at the +5V line.

■ Transistor Q81 goes On. Photo coupler PC1 goes On.

FETQ31 goes On and the gate voltage for Switching FETQ1 is cut off. Switching FETQ1 goes Off.

+5V Line Constant voltage Control Circuit:

Voltage at the +5VDC line is monitored by the regulator IC51. Abnormal voltage at the +5VDC line is detected and the information is fed back to the +5V comparator in the IC, then +5VDC is cut off.

□ +42V Line Over Voltage Protection Circuit:

The output level of the +42V line is monitored by the 2 Zener diodes;ZD52 and ZD87. When the output level of the +42V line exceeds +48V, the Switching FET Q1 goes Off by the following operations.

■ Zener diodes(ZD52, ZD87) detect the voltage which exceeds +48V at the +42V line.

■ Transistor Q81 goes On. Photo coupler PC1 goes On.

FET Q31 goes On and the gate voltage for switching FET Q1 is cut off. Switching FET Q1 goes off.

+42V Line Control Circuit:

The output level of the +42V is detected by the Zener diodes; ZD51, ZD81 to ZD86. When the voltage at the +42V line exceeds +38V, the Switching FET Q1 is controlled by the following operations.

■ Zener diodes(ZD51 and ZD81 to ZD86) detect the voltage over +38V at the +42V line. Photo coupler PC1 goes On.

■ Transistor Q3, Q2 go On and gate voltage for the Switching FET Q1 is cut off.

■ When the voltage level drops under +38V at the +42 line, the photo coupler PC1 and transistors Q3 and Q2 go Off and the Switching FET Q1 goes back On.

□ +42V Line Over Current Protection Circuit:

The output current is monitored by the transistors Q81 and Q82. When the output current is abnormally low, the information is fed back to the primary circuit via the photo coupler PC1 to stop the switching operation.

2.2.2 C209 Main Board

C209 Main control board consists of the following;

■ Logic Circuit(PROM, DRAM,CPU, ASIC, EEPROM)

■ Motor control, Drive Circuits(CR Motor, PF/Pump Motor)

■ Head Control, Drive Circuit(Black and Color heads)

■ Sensor Circuit, RTC Timer Circuit, Reset Circuit

Since EPSON Stylus Photo is the printer designed for output of the photo images/color graphics, there is no CG-ROM.

The figure below shows block diagram for the main board.

Color Sensor Circuit
Figure 2-19. C209 Main Control Board Block Diagram
Table 2-13.Functions of CPU and Gate Array
+1 0

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