Overview

This section describes the operating principles of the printer mechanism and electrical circuit boards. The Stylus COLOR 680/777/777i has the following boards:

NOTE: C383 MAIN-B is compatible with C383 MAIN. Only some chips or parts are different from each other due to different producers.

□ Power supply board: C383 PSB/PSE

2.1.1 Printer Mechanism

The printer mechanism for Stylus COLOR 680/777/777i is designed newly. But, the basic component of the printer mechanism is same as previous product. This printer consists of Print Head, Carriage Mechanism, Paper Feeding Mechanism, Paper Loading Mechanism, Ink System (Pump Mechanism, Cap Mechanism, and Carriage Lock Mechanism).

Like other EPSON ink jet printers, the Stylus COLOR 680/777/777i is equipped with two stepping motors; one for ASF, Paper feeding/ Pump mechanism, and one for CR mechanism. ASF unit uses rear entry front eject system. This ASF unit is also designed newly and single LD roller loads the paper to the printer mechanism.

For cap assembly, Stylus COLOR 680/777/777i uses valveless mechanism; new design for this model.

Epson Stylus 680 Printhead
Figure 2-1. Printer Mechanism block diagram

2.1.2 Printhead

The printhead uses a new developed U-CHIPS head and Stylus COLOR 680/777/777i can perform multiple shot printing and variable printing.

The CSIC is mounted on the ink cartridge. By storing ink life data, this IC makes it possible to control the ink in ink cartridge unit.

The basic operating principles of the printhead, which plays a major role in printing, are the same as previous models; on-demand method which uses PZT (Piezo Electric Element). In order to uniform the amount of ejecting ink, the printhead has its own head ID (6 digits for this printhead) which adjust PZT voltage drive features. The printhead stores the head ID to EEPROM and generates appropriate PZT drive voltage to prevent amount of ink from varying by printheads.

Following explains printhead basic components.

PZT is an abbreviation of Piezo Electric Element. Certain amount of voltage expands and contracts PTZ. The drive wave generated on MAIN board drives PZT and PZT pushes the top cavity which has ink stored to discharge the ink from each nozzle on the nozzle plate.

The ink absorbed from the ink cartridge goes through the filter and then is stored temporarily in this tank called "cavity" until PZT is driven.

The board with nozzle holes on the printhead surface is called Nozzle Plate.

□ CSIC Connection Circuit

This circuit connects the CSIC mounted on the ink cartridge and the main board. One end of the wire harness connects with the print head cable to the main board.

When the ink cartridge is installed, if any dirt or dust around the cartridge needle is absorbed into the head, there is a great possibility of causing nozzle clog and disturbance of ink flow, and finally causing alignment failure and dot missing. To prevent this problem, a filter is set below the cartridge needle, where ink is filtered.

CSIC

Nozzle Selector Board

CSIC

CSIC Connection Circuit

Filter

Nozzle Plate

Cavity

Figure 2-2. Printhead Sectional Drawing 2.1.2.1 Printing Process

CSIC Connection Circuit

Filter

Nozzle Plate

Cavity

Figure 2-2. Printhead Sectional Drawing 2.1.2.1 Printing Process

This section explains the process in which the printheads of On-Demand inkjet printers eject ink from each nozzle.

1. Normal State:

When no printing signal is sent from PC, or no PZT drive voltage is applied, PZT does not change shape, therefore PZT does not squeeze the cavity. Ink pressure inside the cavity is kept normal. (Refer to Figure 2-3.)

2) Ejecting State:

When the print signal is output from the C383 MAIN board, IC (Nozzle Selector) located on the printhead unit latches data once by 1-byte unit. An appropriate PZT

latched by the nozzle selector is pushed into the cavity by the common voltage applied from the main board. By this operation, ink stored in the cavity spurts out from nozzles.(Refer to Figure 2.1.2.2.)

□ Multiple shot printing

This printing mode is developed to improve the print quality on plain paper or transparencies in low resolution. The multiple shot printing mode uses normal dot and the number of dot shots varies from 1 shot to maximum 4 shots depending on the print data to enable sharp image output even in a low resolution.

□ Variable dot printing

This printing mode is developed to improve the print quality on exclusive paper. This mode is basically the same as variable dot printing mode used on other products /; micro dot, middle dot, and large dot compose this mode. Print dot size varies according to print data and this mode enables even sharper image output on exclusive paper.

PZT drive voltage

PZT drive voltage

Figure 2-3. Printhead printing process 2.1.2.2 Printing Method

For print dot system, Stylus COLOR 680/777/777i has the following two kinds of printing modes.

■ Multiple shot printing

■ Variable dot printing

The above two printing modes are automatically selected depending on the media and the resolution setting of the printer driver. The following explains each printing mode.

2.1.3 Carriage Mechanism

The carriage mechanism consists of Carriage motor (CR motor), Carriage unit (including printhead), CR timing belt, CR guide shaft, CR guide frame, CR home detector (HP/PE sensor) etc. The carriage mechanism moves the carriage back and forth according to the drive from the carriage motor. The following stepping motor is mounted to drive CR mechanism. (See the table below.)

Table 2-1. Carriage Motor Specification

Items

Specifications

Type

4-Phase/ 200-Pole HB Stepping motor

Drive Voltage

+42 V +/ - 5% (DRV IC voltage)

Coil Resistance

7.8 Q +/ - 10% (per phase at 25 degree)

Inductance

14 mH +/ - 20%(1KH 1VmA)

Drive Method

Bi-Polar drive

Driver IC

LB11847

The drive from CR motor is transferred to the CR unit via CR timing belt. And the CR home position is detected with the HP/PE sensor. This sensor is available as CR HP detector only in the HP (home position) detection sequence & pump operation sequence. (not available in the paper feeding sequence for the CR HP detector because it is used for only PE sensor during the paper feeding sequence.) Moreover, unlike the previous products, this printer dose not have the PG adjustment mechanism (1.7mm).

Figure 2-4. Carriage Mechanism (Top view)

CR home position is detected with the HP/PE/IC sensor and the detection plate molded in the CR unit as following figure. When the CR home position is detected with this sensor, HIGH signal is output to the CPU.

CR home position is detected with the HP/PE/IC sensor and the detection plate molded in the CR unit as following figure. When the CR home position is detected with this sensor, HIGH signal is output to the CPU.

Figure 2-5. CR home position

2.1.4 Paper Feeding Mechanism

The paper feeding mechanism consists of Paper feed motor (PF motor), PF roller, Paper eject roller, Star wheel roller, and so on. The paper feeding mechanism feeds paper loaded from ASF using the PF roller and Paper Eject Roller & Star wheel roller. For this mechanism, the PF motor mentioned in the right Table 2-2 is used on this product.

The drive of the PF motor is transfer to the PF roller and the Paper Eject Roller as following Figure 2-6. Following shows you how to transfer the PF motor drive to the PF roller and the Paper Eject Roller.

□ PF motor drive transmission path

PF Motor Pinion Gear (CW) ^ Combination Gear 16, 21.6 (CCW) ^ Spur Gear 73.6 (CW) ^ Spur Gear 15 (CCW) ^ Combination Gear 37.6, 44.4 (W) ^ Spur Gear 23.2 (CCW) ^ Spur gear 35.2(CW)

Table 2-2. PF Motor Specifications

Item

Description

Motor type

4-Phase/ 200-Pole HB Stepping motor

Drive voltage

+42 V +/ - 5% (DRV IC voltage)

Coil Resistance

7.8 Q +/ - 10% (per phase)

Inductance

13.5 mH +/ - 20%(1kH 1Vrms)

Driving method

Bi-Polar drive

Driver IC

LB11847

Feed Motor 1400 Epson

PF roller

Spur Gear 15

PF roller

Spur Gear 15

Spur Gear 35.2

Spur Gear 23.2

Combination gear 37.6, 44.4

Spur Gear 35.2

Spur Gear 23.2

Combination gear 37.6, 44.4

Figure 2-6. Paper Feeding Mechanism

Paper loaded from ASF is advanced by the following roller.

□ Paper feed roller & Paper guide roller (assembled on the Top Frame) ^ Paper eject roller & Star wheel roller (assembled on the Paper eject frame).

Additionally, the top & end of the paper is detected with the HP/PE sensor. In case the PE sensor dose not detect the paper in the paper loading sequence, the printer detects the "Paper out error". If the paper is detected after complete the paper eject sequence, the printer detects the "Paper jam error".

2.1.5 Paper Loading Mechanism (ASF Unit)

The Paper loading mechanism is positioned at the printer rear. The Paper loading mechanism loads paper at the ASF unit and feeds paper to the PF roller.

This ASF unit was designed newly for this product and consists of LD roller, Pad holder (Paper return plate), ASF Frame, Hopper, and so on.

For the major feature of this ASF unit, ASF HP sensor is not used and the single LD roller is built in the ASF unit.

Drive sent from the PF motor is always transmitted to the ASF unit side. But, the Change lever and the Clutch mechanism switch ON/OFF the PF motor drive to the LD roller with the motor rotational direction.

Drive from the PF motor is transmitted to the ASF unit as described below:

□ Switch the PF motor drive to ASF unit side

PF Motor pinion gear rotates CCW direction with a specific steps s Combination Gear 16, 21.6 (CW) s Spur Gear 73.6(CCW) s Spur Gear 15(CW) s Combination Gear 37.6, 44.4 (CCW) s Change Lever rotates (CCW) s Release the Clutch mechanism lock position

Following Figure 2-7 shows you the switching path for PF motor drive to ASF unit side.

□ Transfer the PF motor drive to LD roller

PF Motor pinion gear rotates CW directions Combination Gear 16, 21.6 (CCW) s Spur Gear 73.6 (CW) s Spur Gear 15 (CCW) s Combination Gear 37.6, 44.4 (CW) s Change Lever rotates (CW) s Spur Gear 23.2 (CCW) s Spur Gear 35.2 (CW) (include the clutch mechanism) s LD roller (CW).

Following Figure 2-9 shows the PF motor drive transmission path to the LD roller unit built in the ASF unit. The LD roller is assembled on the same shaft that the Spur gear 35.2 is assembled.

Figure 2-8. PF motor drive transmission path
Change Lever

Spur Gear 15

Spur Gear 15

Printer Spur Unit

Spur Gear 23.2

Spur Gear 35.2

Spur Gear 23.2

Combination Gear 37.6, 44.4

Figure 2-7. Switch the PF motor drive to ASF unit side

When the PF motor torque is switched to the ASF unit side by the clutch mechanism, the function of the ASF mechanism varies depending on the rotational direction of the PF motor, as shown in the table below.

Table 2-3. ASF unit function & PF Motor rotational direction

Directions

Corresponding Functions

Clockwise (* 1)

• Picks up and loads paper

Counterclockwise (* 1)

• Release the DE lever & Clutch mechanism

(*1): The PF Motor rotational direction = seen from the right side of the printer. □ Clutch Mechanism

Unlike the previous products, this product dose not have a ASF HP sensor. Instead of the ASF HP sensor, Change lever and the Clutch mechanism are used to detect the ASF home position. Following figures describe the mechanism.

NOTE:

The Clutch gear is molded on the back side of the Spur gear 35.2 such as Combination gear.

NOTE:

The Clutch gear is molded on the back side of the Spur gear 35.2 such as Combination gear.

Figure 2-9. Disengage & Clutch mechanism

The Clutch mechanism transmits the PF motor drive to the LD roller shaft only when the Clutch gear rotates CW direction after the Change lever releases the Clutch lever. If the Clutch gear rotates CCW direction, the PF motor drive is not transmitted to the LD roller. This is due to the combination of the shape of the Clutch gear and the Clutch lock tooth such as described on the figure.

1. When the paper is advanced with the PF roller, the Change lever is set on the Clutch lever and the Clutch is pushed down as above Stepl's figure. As the result, the Clutch gear (* 1) is released from the Cluck lock tooth and the drive from the PF motor is not transmitted to the LD roller shaft.

2. When the PF pinion gear rotates CCW direction in the above Step2's figure, the Change lever moves to the left direction with the CCW rotation of Combination gear 37.6, 44.4. The Clutch turns back to the engagement position by the tension force of the Tension spring 0.143 and the Clutch gear is engaged with the Clutch lock tooth as above Step2's center figure.

3. When the PF pinion gear rotates CW direction in the above Step3' s figure, the Change lever moves to the right direction with the CW rotation of the Combination gear 37.6, 44.4. And the drive from the PF motor is transmitted to the LD roller shaft via Clutch gear and Clutch lock tooth.

4. The LD roller shaft rotates about 360 degree and the Change lever push the Clutch lever and the PF motor drive is interrupted. This position is the ASF home position.

Unlike the previous products, The Paper return plate is built in the ASF frame instead of the Paper return lever. The Paper separation pad is also stacked on the plate. It works with the spring force of the Torsion spring 25.7 (mounted in the ASF frame)

Figure 2-10. Paper Return Plate

The Paper return plate is set to return the paper to the paper stand-by position in the ASF unit when the ASF unit is in the standby mode. When the paper is fed with the LD roller, the Paper return plate is stored in the ASF frame by the LD roller.

Following figures show you the ASF paper loading sequence and the operation of the each mechanism.

□ Paper Return Plate (Pad holder)

When the paper is advanced with the PF roller, Change lever push down the Clutch lever as right figure and the Clutch lock tooth is disengaged from the Clutch gear. As the result, the drive from the PF motor is interrupted and the LD roller dose not rotate. This position is the ASF home position.

The Paper return plate is set to avoid that the paper is slipped down from the paper set position.

The PF motor pinion gear rotates CW direction and the drive from the PF motor is transmitted to the ASF LD roller shaft through the Clutch lock tooth and the Clutch gear. The ASF hopper release lever rotates with the ASF LD roller and release the ASF Hopper. The ASF hopper is pushed with the Compression spring 4.80 and the paper is picked up with the ASF LD roller.

LD roller LD roller shaft Paper return plate

Sharp Through Hole Pcb Photointerrupter

Figure 2-11. ASF Paper Loading Sequence

When the paper is loaded (pick up) from the ASF unit, the Change lever moves to the printer front side with the CCW rotation of the PF motor pinion gear and releases the Clutch lever. As the result, the Clutch turns back to the engagement position by the tension force of the Tension spring 0.143. And the Clutch lock tooth is engaged with the Clutch gear as right figure.

The ASF LD roller rotates CW direction moreover and the Paper return plate is stored under the ASF frame. The paper is advanced up to the PF roller. and the ASF LD roller & the clutch rotate to the "Stepl" position. The Clutch lever is locked with the Change lever. The drive from the PF motor is interrupted and the drive is transmitted to the PF roller side.

Figure 2-11. ASF Paper Loading Sequence

2.1.6 Ink System Mechanism

Ink system mechanism consists of pump unit (include the CR lock lever) and capping mechanism. Ink system mechanism drives the pump unit that presses cap to the printhead and ejects ink from ink cartridge, head cavity and cap to the waste ink pad.

2.1.6.1 Pump Unit & Wiper mechanism

The pump unit is driven by PF motor. PF motor drive is always transmitted to the paper feeding mechanism and pump unit through the following gears. Refer to the Figure 2-13.

PF Motor Pinion Gear (CW) ^ Combination Gear 16, 21.6 (CCW) ^ Spur Gear 73.6 (CW) ^ Spur Gear 15 (CCW) ^ Combination Gear 37.6, 44.4 (CW) ^ Spur Gear 36.8 (CCW) ^ Combination Gear 9.6, 24 (CW)^ Pump Unit Gear (CCW)

The Pump unit and Wiper mechanism drives according to the PF motor rotational direction, as shown in the right table.

Table 2-4. PF motor rotational direction & Ink System Mechanism

Directions

Functions

Counterclockwise (* 1)

• Absorbs ink by the pump unit

• Set the CR lock lever

Clockwise (* 1)

• Resets the wiper.

(*1): The PF Motor rotational direction = seen from the right side of the printer. Following figure shows the overview of the pump mechanism operation.

(*1): The PF Motor rotational direction = seen from the right side of the printer. Following figure shows the overview of the pump mechanism operation.

Figure 2-12. Pump mechanism
Figure 2-13. PF motor drive transmission path to the Pump unit

2.1.6.2 Capping Mechanism

The capping mechanism covers the printheads with the cap holder to prevent the nozzle from increasing viscosity when the printer is in stand-by mode or when the printer is off. This product has valveless cap system. Air valve function used for the previous models pumps and ejects ink only inside the cap by absorbing ink with the valve open. By opening the Air valve, the negative pressure is decreased and only the ink inside the cap is ejected. (the ink is not absorbed from Ink cartridge or head cavity.) But, valveless cap system, this operation is done out side of the capping area. The CR moves to left side of the Cap assembly and the pump absorbs the ink inside the cap.

Viewed from front side

Viewed from front side

Images Negative Pressure Ink System
Figure 2-14. Cap Mechanism

2.2 Electrical Circuit Operating Principles

The electric circuit of the Stylus COLOR 680/777/777i consists of the following boards.

□ Main board: C383 MAIN Board

□ Power supply board: C383 PSB/PSE Board

□ Panel board: C383 PNL Board

This section provides operating principles of C383 Board and C383 PSB/PSE Board. Refer to Figure 2-15 for the major connection of the each boards and their roles.

2.2.1 C383 PSB/PSE board

The power supply boards of Stylus COLOR 680/777/777i use a RCC (Ringing Chalk Converter) circuit, which generates +42VDC for drive line and +5VDC for logic line to drive the printer. The application of the output voltage is described below.

Table 2-5. Application of the DC Voltages

Voltage

Application

+42VDC

• Printhead common voltage

• Printhead nozzle selector 42V drive voltage

+5VDC

• C383MAIN control circuit logic

• Sensor

AC voltage input from AC inlet first goes through filter circuit that removes high frequency components and is then converted to DC voltage via the rectifier circuit and the smoothing circuit. DC voltage is then lead to the switching circuit and FET Q1 preforms the switching operation. By the switching operation of the primary circuit, +42VDC is generated and stabilized at the secondary circuit. This +42VDC generated by the secondary circuit is converted to +5VDC by the chopping regulator IC of the secondary circuit.

Printer Mechanism

Printer Mechanism

+5VDC +42VDC

PSB/PSE Board

Figure 2-15. Electric Circuit

+42VDC M

+5VDC

IC51

PSC Sigual from Main board

+5VDC Line Over Voltage Limitation

ZD52,87

+42VDC Line Over Voltage Limitation

ZD91

R92,R93,Q91,ZD51

+42VDC Line Constant Control

+42VDC Line Drop Limitation

C84,Q84

Smoothing Circuit

Power Drop Delay Circuit

Photo Coupler

TRANS(T1)

Smoothing Circuit

Main Switching Circuit

Q2,Q31,Q32,Q33

Abnomal Feed back circuit

Over Current

Protection

Filter Circuit

F1,TH1

AC Input

Filter Circuit

Full Wave Rectifier circuit

F1,TH1

L1,C1

AC Input

Figure 2-16. C383PSB/PSE Board Block Diagram

The C383 PSB/PSE board has the various control circuits to stop voltage output if a malfunction occurs on the power supply board or the main board while the printer mechanism is on duty. Following explains each control and protection circuit.

Regardless of the state of the power switch (On or OFF), the voltage is always applied to the primary side of the power supply board from the moment or at the state that AC-plug is plugged in. At this time, F1 plays a role of preventing AC100V from coming into the F1.

L1 also prevents high harmonic wave noise generated in the RC circuit filter which consists of C1 from going out, and eliminates the noise from outside here.

The AC is full-wave rectified by the diode bridge DB1, and converted to -J2 x AC in voltage by the smoothing electrolytic capacitor C11.

3. The pressured up direct current turns Q1 on through the starting resistor R31 and starts the primary side of the circuit.

4. When the primary side is On, the energy (current) led by the electromagnetic induction through the trans (T1) does not flow to the secondary side since the diode (D51) on the secondary side is installed in the opposite direction.

5. When the energy which is charged in the trans is reaching the saturated state, the voltage which makes Q1 on becomes weak gradually. At the point that this voltage drops at the certain voltage, C13 absorbs the current in the opposite direction and Q1 is quickly shut off by the resulting sharp drop.

6. When the primary side is turned off, the energy charged in the T1 is opened according to the diode(D51) direction which is installed on the secondary side. Basically, 42 V DC is output by these circuit operations and the number of T1 spiral coil.

7. +5VDC is generated by pressured down this +42VDC as power supply. IC51 pressures down the +42VDC and generates precise +5VDC by chopping off the output, forming the standard santooth wave form by the outer RC integration circuit.

The C383PSB/PSE board has the various control circuits to stop voltage output if a malfunction occurs on the power supply board or the main board or while the printer mechanism is on duty. Following explains each control and protection circuit.

□ +42V Line Constant Voltage Control Circuit:

The output level of the +42V line is monitored by a detection circuit composed of the seven Zener diodes. This circuit prevents the voltage from dropping for a constant level of the output voltage.

□ +5V line over voltage protection circuit:

This protection circuit is in the same line as the +42V over voltage protection circuit is located. The output voltage level of the +5V line is monitored by a Zener diode. This circuit shuts down the +5V line forcefully when the voltage level exceeds +9V.

□ +42VDC line drop limitation circuit:

This protection circuit is in the same line as +42V over voltage protection circuit is located. The output voltage level of the +42V line is monitored by a Zener diode. This circuit shuts down the +42V line forcefully when the voltage level drops to +36V.

□ +42VDC line over voltage circuit:

This circuit is in the same line as +5V line over voltage protection circuit is located. The output level is monitored by two Zener diodes. If the voltage level exceeds +48VDC, this circuit shuts down the +42V line forcefully.

□ +5V line constant voltage/constant current control circuit:

The output current is monitored by the +5VDC generation switching control IC (IC51), which also monitors the output voltage. This information is input to the internal comparator and stabilizes +5V line. The operations of the secondary side switch are explained below.

■ When the power is turned on, Q1 repeats on/off automatically along with the increase and decrease of energy on the trans coil at the primary side. While the power is on, the PSC signal is input to the power supply board from the C383MAIN board.

■ This signal turns Q84 on and it becomes possible to discharge energy between the terminals 8 and 9 of T1. At this time, even if the power is turned off, the electrolytic capacitor keeps Q84 on for a while, and by this electrolytic capacitor, voltage output is held at least 30 seconds. This time helps the printer to complete a power-off operation.

2.2.2 C383 MAIN Board

The printer mechanism is controlled by C383 MAIN. See Figure for the C383 MAIN board block diagram.

Epson Stylus Color Main Board
Figure 2-17. Block Diagram for the C383 MAIN Board

Following shows you the major characteristic of this main board.

□ Use of the 3.3 V chips in the logic circuit

The 3.3 V regulator (IC11) on the C383MAIN produces 3.3 V by pressuring down the 5.5 VDC, also generated on this board, to drive several chips. See the table below that separately shows the chips driven by the +5V and +3V.

Table 2-6. 3.3V Drive Chips & 5.5V Drive Chips

+5V

3.3V

Sensors I/F Circuit PNL Board

P-ROM

D-RAM

□ Timer IC & Lithium battery are not mounted

Unlike the previous products, the Timer IC and the Lithium battery are not mounted on the Main board. So, this product perform the Power-on cleaning or Timer cleaning based on the time command which is sent from the printer driver.

4Mbit and 16Mbit D-RAMS are mounted on the Main board.

□ One CPU controls the all function on the main board.

2.2.2.1 Main elements

Table 2-7 shows the function of the each main elements on C383 MAIN.

Table 2-7. Main Elements of the C383MAIN

IC

Location

Function

E01A15CA

IC9

16bit CPU mounted on the MAIN board is driven by clock frequency 24MHz and controls the printer.

PROM

IC1

• Program for CPU

RAM

IC5, IC8

Bus= 16 bit, 4Mbit DRAM and 16Mbit DRAM

1kbit EEPROM

EEPROM

• Parameter backup

Reset IC

Reset IC

IC16

• For +42V, reset when +33.2 is detected

Common Driver

IC10

Head drive control HIC • Generates head common voltage.

Motor Driver

IC12

CR motor drive IC

Motor Driver

IC13

PF motor drive IC

Parallel I/F IC

IC6

IEEE1284 parallel I/F transceiver IC.

USB IC

IC2, IC3

USB transceiver IC

selector IC on the head board. Print data is converted to serial data by the CPU (IC9) and then sent to the nozzle selector IC on the head board. Based on the serial data, the nozzle selector IC determines the nozzles to be actuated. The selected nozzles are driven by the drive waveforms produced by the common driver. See Figure 2-18 for the printhead driver circuit block diagram.

□ Head common driver circuit

The reference head drive waveform is produced in the common driver (IC10:E09A14RA) based on the following 12 signal lines output from the ASIC (lC8 E05B70CD); A0-A4, CLK1, CLK2, RST, FLOOR, DATA, DCLK, and E. By the DATA signal output from the CPU (IC9), the original data for the head drive waveform is written in the memory in the IC10. The addresses for the written data are determined by the A0 - A4 signals, and, of among, data used to determine the waveform angles is selected. Then, setting the selected data, producing trapezoid waveform value, and canceling the data are performed by the rising edges of the CLK1 and CLK2 signals.

□ Head nozzle selector circuit

Printing data is converted into serial data by the CPU (IC9). Then the converted data is allocated to the six rows, the number of the head nozzle rows, to be transferred to the nozzle selector through the six signal lines (HS01 to HS06). Data transmission from the CPU (IC9) to the nozzle selector synchronizes with the LAT signal and SCK clock signal. Referring to the transferred data, nozzles to be activated are selected, and the PZTs of the selected nozzles are driven by the drive waveform output from the head common driver.

2.2.2.2 Printhead Driver Circuit

The printhead driver circuit consists of the following two components:

■ Common driver IC (IC10:E09A14RA) directly attached to the C383MAIN board.

■ Nozzle selector IC on the head board.

The common driver (IC10:E09A14RA) generates a reference drive waveform according to the output signals from the C383MAIN board. The reference drive waveform is amplified by the transistors Q2 and Q3and then transferred to the nozzle

HWAO HWA1 HWA2 HWAS HWA4 HWCLK1 HWCLK2 HWFLR HWRST HWSDATA HWSCLK HWSLAT

IC9 CPU E01A15CA

HCH HLAT CRAIO CRAI1

SWCO

SWC1

HSO1

HSO2

HSOS

HSO4

HSO5

HSOS

HSOCMD

HNCHG

HSOCLK

AO A1 A2 AS A4 CLK1 CLK2 FLOOR RST DATA DCLK E

COM COM COM COM

COM COM COM COM

IC10

Commom Driver IC

COB COA

512 SIS

515 SIS SP

NCHG

IC10

Commom Driver IC

COB COA

512 SIS

515 SIS SP

NCHG

Head Drive Pulse

CPU (IC9) converts PF motor phase control signal to LB11847 micro step drive form and outputs to motor driver IC (IC13) LB11847 from port 101, 112. Based on this signal, IC13 determines the phase mode.

The current value on each phase is determined by CPU (IC9) and outputs from port 104, 105, 107, 108, 109, 110 to driver IC (IC13). Motor driver IC generates motor driver waveform based on these input signals and controls the motor. If the printer dose not receive any data from PC for 5 minutes, CPU set the motor drive current to 0 via port 104, 105, 107, 108, 109, 110 and the motor drive is turned off to save the power consumption.

EO1A15CA (ICe)

PFAI 1 PFAI 2 PFAI S

PFBI 1 PFBI 2 PFBI S

PFPHAA PFPHAB

PFENBA PFENBB

LB11847-K (IC1S)

OUTA

OUTB

ENABLEl ENABLE2

VHEFl VHEF2 CRlF VCC CR2 MD

DECAYl DECAY2 El GND

OUTB

SS

()))))))))

e2

Rotor

8 4

+42V

Figure 2-18. Printhead Driver Circuit

2.2.2.3 PF Motor (PF/ PUMP/ ASF Motor) Driver Circuit

The motor driver IC (IC13) on the MAIN board drives PF motor. This product uses 4-phase 200-pole hybrid type stepping motor and performs constant current bi-polar drive.

Figure 2-19. PF Motor Driver Circuit Block Diagram

PHASE2

2.2.2.4 CR Motor Driver Circuit

2.2.2.5 Reset Circuit

The motor driver IC (IC12) on the MAIN board drives PF motor. This product uses 4-phase 200-pole hybrid type stepping motor and performs constant current bi-polar drive.

CPU (IC9) converts PF motor phase control signal to LB11847 micro step drive form and outputs to motor driver IC (IC12) LB11847 from port 81, 94. Based on this signal, IC12 determines the phase mode.

Reset circuits consist of the rest IC (IC16). Reset circuits are mounted on the MAIN board to monitor the two voltages: +5V for the logic line and +42V for the drive line. When each circuit detects abnormality on the corresponding line, it outputs a reset signal to reset CPU (IC9). This function is necessary to prevent the printer from operating abnormally. This IC monitors both +5V and +45 lines but can reset them independently. The reset circuits outputs reset signal when +5V line becomes 4.2V or lower or +42V line becomes 33.2V or lower.

The current value on each phase is determined by CPU (IC9) and outputs from port 83, 84, 85, 86, 87, 88, 90, 91 to driver IC (IC12). Motor driver IC generates motor driver waveform based on these input signals and controls the motor. If the printer dose not receive any data from PC for 5 minutes, CPU set the motor drive current to 0 via port 83, 84, 85, 86, 87, 88, 90, 91 and the motor drive is turned off to save the power consumption.

E01A15CA (IC9)

CRAI 0 CRAI 1 CRAI 2 CRAI 3 CRBI 0 CRBI 1 CRBI 2 CRBI 3

CRPHAA CRPHAB

CRENBA CRENBB

84

24

85

23

86

22

87

18

88

19

90

20

91

21

81

27

94

16

82

26

93

17

122

2

13

3

PHASE1

PHASE2

LB11847-K (IC12)

OUTA

OUTB

63

92

Rotor

84

ENABLE1 ENABLE2

VHEF1

VHEF2

CR1F

DECAY1 DECAY2 E1 E2

+42V

Figure 2-20. CR Motor Driver Circuit Block Diagram

Unlike the previous products, the timer IC is not built in the reset IC and the Lithium battery also is not equipped on the main board.

IC16 BH6150F-E2

NC1 IN

NC2 GND

MRES VCC OUT1 OUT2

8

119

7

6

128

5

127

IC9 E01A15CA

NMI RESET

Figure 2-21. Reset Circuit Block Diagram

Main signal lines are explained below;

■ OUT1: Interrupt signal

PHASE1

PHASE2

2.2.2.6 EEPROM Control Circuit

Since EEPROM is nonvolatile memory, it keeps written information if the printer power is turned off. When the printer is turned ON, CPU (IC9) reads data from EEPROM (IC15) and when the power is turned OFF it stores data to EEPROM.

Information stored in EEPROM is listed below.

■ Various ink counter (I/C consumption counter, waste pad counter, etc.)

■ Mechanical setting value (Head ID, Bi-D adjustment, USB ID, etc.)

See Table 7-9, "EEPROM Address Map," on page 124 that provides detailed information on the values stored in EEPROM.

EEPROM-93C (IC15)

VCC NC ORG GND

E01A15CA (IC9)

2

97

3

96

4

Figure 2-22. EEPROM Circuit Diagram

EEPROM is connected to CPU with 4 lines and each line has the following function.

■ CS: Chip selection signal

■ CK: Data synchronism clock pulse

■ DI: Data writing line (serial data) at power off.

■ DO: Data reading line (serial data) at power on.

2.2.2.7 Sensor Circuit

C383 MAIN is equipped with the following two sensors to detect the status of the printer. Unlike the previous product, ASF HP sensor is not equipped on the ASF and the ASF HP is determined with the clutch mechanism ("Paper Feeding Mechanism").

This sensor uses photo interrupter method and detects the following three status. The photo interrupt component and two detection levers consists of this sensor.

■ CR home position

The CR home position is detected on the right edge of the CR shaft with the HP/PE sensor during the power on sequence. In case the CR home position is detected in the power on sequence, this sensor outputs HIGH signal to the CPU.

When the LOW signal is output to the CPU in the detection position, the CR unit is out of home position.

When the Paper is in the paper path, this sensor outputs the HIGH signal. When the Paper is not in the paper path, this sensor outputs the LOW signal. This status is always monitored during the printer is in the power on status with this sensor.

The thermistor is attached directly on the printhead driver board. It monitors the temperature around the printhead and determines the proper head drive voltage according to the ink viscosity that varies by the temperature. This information is fed back to the CPU analog port. When the temperature rises, the head drive circuit lowers the drive voltage: When the temperature lowers, the head drive circuit rises the drive voltage.

The block diagram for the sensor circuit is shown below

Current Flow Diagram Car Lights

CA4 HP/PE Sensor

CN9 Head FFC

CA4 HP/PE Sensor

Figure 2-23. Sensor Circuit Diagram

TROUBLESHOOTING

CHAPTER

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