Epson Stylus Photo Service Manual 2
Chapter 2
Operating Principles
2.1 OVERVIEW............................................................................................................2-1
2.1.1 Printer Mechanism ................................................................................................................. 2-1
2.1.1.1 Printing Mechanism................................................................................................... 2-2
2.1.1.2 Carriage Mechanism ................................................................................................. 2-7
2.1.1.3 Paper Feed Mechanism and Pump Mechanism......................................................2-11
2.1.1.4 Ink System............................................................................................................... 2-14
2.2 Electrical Circuit Operating Principles.............................................................2-18
2.2.1 C206 PSB/PSE Power Board ............................................................................................... 2-18
2.2.2 C209 Main Board .................................................................................................................. 2-20
2.2.2.1 Reset Circuits..........................................................................................................2-21
2.2.2.2 Sensor Circuits........................................................................................................2-22
2.2.2.3 EEPROM Control Circuits ....................................................................................... 2-23
2.2.2.4 Timer Circuit............................................................................................................2-24
2.2.2.5 Print Head Drive Circuit........................................................................................... 2-25
2.2.2.6 Motor Drive Circuits................................................................................................. 2-27
2.1.1.1.1 Printing Process.............................................................................................2-3
2.1.1.1.2 Printing Method..............................................................................................2-4
2.1.1.2.1 Paper Gap Adjust Mechanism ..................................................................... 2-10
2.1.1.4.1 Pump, Carriage Lock, Head Cleaner Mechanism........................................ 2-15
2.1.1.4.2 Cap Mechanism...........................................................................................2-17
2.3 Ink System Control.............................................................................................2-28
2.3.1 Ink System Basic Functions................................................................................................2-28
2.3.2 Timers and Counters............................................................................................................ 2-29
2.3.3 Ink System Sequence...........................................................................................................2-30
Chapter2 Operating Principles
2.1 OVERVIEW
This section describes Printer Mechanism, electric circuit board (C206 PSB/PSE, C209 Main, C209PNL
board) of EPSON Stylus Photo.
2.1.1 Printer Mechanism
Unlike the previous EPSON Ink Jet printers, printer mechanism of EPSON Stylus Photo does not have
exclusive mechanism to change over paper feeding and pumping operation. In stead, this control is done
by the turning direction of paper feed/pump motor and changing the position of carriage at that time.
Also, unlike previous print heads, the print head of this printer became one unit combined with black,
CMY(Cyan, Magenta, Yellow), LM(Light Magenta) and LC(Light Cyan) head. Black head has 32 nozzles,
90 dpi(vertical direction) and CMY, LC, LM head has 32 nozzles for each color, 90 dpi (vertical direction).
Also, since these print head is driven by frequency 14.4KHz, this printer can print twice faster (200-dpi)
than Stylus Color even at 720-dpi high resolution printing. Since the head drive frequency of Stylus Color
was 7.2KHz, it was driven by 100-cps printing speed in order to perform 720-dpi printing.
Following figure2-1 shows outline of the printer mechanism
Carriage Unit
(Prinr Head Unit)
.
Platen Drive Mechanism
Paper Pickup Mechanism
Pump Drive Mechanism
Timing Belt
Paper Pick Up
Trigger Lever
Pumping Position
Paper Feed Motor
Rev. A
Carriage Motor
Figure 2-1. EPSON Stylus Photo Printer Mechanism Block Diagram
2-1
EPSON Stylus Photo
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As you can see major printer mechanisms in the figure 2- 1, there are four m ajor mechanis ms as they are
listed below.
1) Printing mechanism 2) Carriage drive unit 3) Paper pick up mechanism 4) Pump drive mechanism
2.1.1.1 Printing Mechanism
Basic operating principles of the print head which plays major role of printing mechanism is the same as
previous models; on demand type MACH head method, but there is some differences in the resolution.
(Refer to figure1-1) Also, unlike Stylus Color II, Stylus 820 and Stylus Color 200 automatic correction type,
in order to fix the dispersion of mufti layer piezo electric element which is used for driving each nozzles, it
is necessary to input the VH value written on the side of print head by using exclusive program when you
replace the print head, control board, or the printer mechanism.(However, there are no resistor array to
decide the VH voltage on the main control board.) Following explains the print heads.
PZT
PZT is an abbreviation of Piezo Electric Element. Print signal from C209 board is sent through the
driver board on the print head unit and to the PZT . Then, the PZT pushes the top cavity which has
ink stored, and make the ink discharge from each nozzle located on the nozzle
plate.
Cavity Set
Ink which is absorbed from ink cartridge go through the filter and will be stored temporarily in this
tank, which is called “cavity”, until PZT is driven.
Nozzle Plate
The board with nozzle holes on the printer head surface is called Nozzle Plate.
Filter
When the ink cartridge is installed, if any dirt or dust around the cartridge needles are
absorbed into the head inside, there is a great possibility of causing nozzle clog and
disturbance of ink flow and finally causing alignment failure and dot-missing. In order to
prevent this, filter is set at cartridge needle below and ink is once filtered here.
PZT
Nozzle Plate
Printhead driver board
Ink Cartridge Sensor
Actuator
Cartridge needle
(Ink Cartridge)
Filter
Ink Supply Tube
Cavity set
Figure 2-2. Print Head Sectional Drawing
2-
Rev. A
Chapter2 Operating Principles
3
2.1.1.1.1 Printing Process
Following figures indicate the sectional drawing of normal state and ejecting state of print head.
(1) Normal State:
When the printing order is not output, PTZ also does not move and stays in the waiting mode
(normal state).
PZT
Cavity
Ink Course
Nozzle
Figure 2-3. Print Head Normal State
(2) Ejecting State:
When the print signal is output from the C209 main board, IC(IR2C72C and IR2C73C:Nozzle
Selector) located on the print head unit latches the data once by 1-byte unit. Appropriate PZT latched
by nozzle selector is pushed in to the cavity by applying common voltage from the C209 main
board. By this operation, ink that is stored in the cavity pops out from nozzles.
Nozzle Plate
Figure 2-4. Print Head Ejecting State
Rev. A
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EPSON Stylus Photo
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2.1.1.1.2 Printing Method
This section explains printing method of actual printing such as printing text at various resolution
select/printing mode and graphics printing. In order to prevent white or color banding which are peculiar
problem of ink-jet, new Micro-Weave functions are added to the previous Micro-Weave function. The
number of nozzles and printing mode according to the selected resolution are used separately by a user.
The table below shows relation between selected resolution and printing mode.
1) Full Overlap Micro-Weave
2) Part Line Overlap Micro-Weave
3) Micro-Weave: (same as previous control)
Table 2-1. Resolution and Printing Mode
Vertical
direction
[dpi]
360 FOL M/W 15/360 #16•`#30 --- #1•`#15 #31, #32
720 FOL M/W 15/720 #16•`#30 --- #1•`#15 #31, #32
Note1:
M/W means Micro-Weave.
Note2:
Note3:
Note4:
Following explains operation outlines of new Micro-Weave functions listed above.
[1. Full Overlap Micro-Weave]
In order to print one line at horizontal direction, this printing method is designed to complete a printing
pattern by two-pass carriage operation with two different types of dot. When these two different types of
dot pass one same line twice, it does not print the same dot twice. Following explains the outline of this
movement.
FOL means Full Overlap Micro-Weave.
POL means Part line Overlap Micro- Weave
Forward Overlap-Nozzle and backward Overlap -Nozzle are described in the [1.Full Overlap
Mirco-Weave] and [2.Part line Overlap Micro-Weave] below.
The number of all nozzles which are going to be used are divided equally into 2 groups.
Paper feeding will be done as many as each number of nozzles which are divided into two groups
and the same number of dots.(for example, if there are two 10-nozzle groups during 360-dpi
printing at longitudinal direction, paper feeding of 10/360-inch becomes available.)
At this time, two groups perform Micro-Weave individually and particular lines are passed by
two different nozzles.
Printing
mode
M/W 31/360 --- #1•`#31 --- #32
POL M/W 29/720 #30•`#32 #4•`#29 #1•`#3 ---
Paper feed
pitch
[inch]
Forward
Overlap-
Nozzle
Non
Overlap-
Nozzle
Backward
Overlap-
Nozzle
Not used
Nozzle
.
Note1)
Two groups which are divided according to each elements will be divided either even dot or
odd dot when particular lines(level direction line) are formed and eventually, these lines will be
completed at selected resolution. Following is a conceptual figure when full overlap microweave forms a particular line.
Nozzle No.#9
Condition: 360-dpi printing
Nozzle: Total 10 nozzle/each color
Nozzle No.#4
Particular line(Completed line)
Figure 2-5. Full Overlap Micro-Weave
2-
360-dpi
Rev. A
Chapter2 Operating Principles
5
Note 2)
If the line which is about to be printed is even line:
If the line which is about to be printed is odd line:
[2.Part Line Overlap Micro-Weave]
This printing method is to perform Micro-Weave printing, overlapping part of nozzles which are
used for printing. As a result, a part of line which is overlapped consists of different browse with
different nozzles. The figure below shows 1-line overlap at 5-dot sending as an example with
explanation on the next page.
The way firmware decides which nozzle becomes even dot or odd dot is determined
as it is described below.
First dot prints odd dot lines and 2nd dot prints even dot lines.
1st dot prints even dot lines and 2nd dot prints odd dot lines. Eventually, horizontal resolution
will be the same resolution as selected one.
Pass1
#1
#2
#3
#4
#5
2
3
Note1: The paper feed pitch is 5/360-dpi in this figure.
Note2: Mark of and mean overlap nozzle.
4
5
Raster 1
#6
6
7
Raster 10
8
9
10
11
Figure 2-6. Part line Overlap Micro-Weave
Rev. A
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EPSON Stylus Photo
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The difference between Full-Overlap Micro-Weave and Part line Overlap Micro-Weave are
following;
Full-Overlap Micro-Weave:
Printing is performed, judging if nozzles are even or odd dot by 2 different dots in all
different lines.
Part line Overlap Micro-Weave:
After particular nozzles(only#1, and #6 in the figure2-6) are determined as overlap nozzles,
even or odd dot will be determined like Full-overlap Micro-Weave does.
(Forward Overlap Nozzle is determined as even and backward nozzle is odd.)
Also, nozzles other than particular nozzles can print at even and odd dot just by one
nozzle.
1) Overlap Nozzle : Head drive frequency is driven half of the ordinal one like 2)
below.
2) Nozzle other than Overlap nozzle : Head drive frequency is twice as much as overlap nozzle.
Usually, the firmware changes over automatically these full overlap Micro-Weave, Part line Overlap
Micro-Weave, and ordinal Micro-weave according to the selection of resolution. Also, when these three
printing modes are performed by the EPSON Stylus Photo, the printer performs top and bottom margin
process in order to control the overprinting volume as little as possible.
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Rev. A
Chapter2 Operating Principles
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2.1.1.2 Carriage Mechanism
Carriage mechanism is to drive the carriage with print head from left to right or vice versa.
The carriage drive motor in this printer is a 4-phase, 200-pole stepping motor and is driven by
1-2phase, 2-2phase and W1-2phase drive method. This stepping motor allows the carriage to
move freely to the particular positions which is necessary for various operation, such as paper feeding,
ink absorbing, flashing, ink exchange and cleaning operations. The tables below show carriage motor
specifications and motor controls at each mode.
Table2-2. Carriage Motor Specification
Item Description
Motor type 4-phase/200-pole Stepping motor
Drive voltage Range
Internal coi l resistance
Driving speed(frequency) range[cps (pps)] 5(60) - 340(4080)
Control method Bi-Pola Drive
Table 2-3. Motor Control at each mode
42VDC ±5%
7.8 Ohms ±10%
(per phase under 25°C environment)
Mode Driving speed
[CPS]
High speed skip 340 4080 W1-2, 2-2,1-2phase drive*
Printing(1→ 80 column direction)
Printing(80→ 1 column direction)
Capping 80 960 W1-2phase drive
Wiping 40 480 W1-2phase drive
Cap(valve released) 20 240 W1-2phase drive
Cap (Release) 5 60 W1-2phase drive
*Note 1):
Acceleration 1 mode → Acceleration 2 mode → Deceleration 1 mode → Deceleration 2 mode
The reason why plural drive methods exist is that following some sequences described below
exist in the each mode and, more stable carriage operation and printing are performed
individually by different drive methods. This drive method is necessary especially for high
speed skip.
200 2400 W1-2phase drive
200 2400 W1-2phase drive
Drive frequency
[PPS]
Drive method
1
A
3
/A
C209 MAIN Board
Rotor
2
CN6(CN7)
B
4
/B
Figure 2-7.CR(PF/Pump) Motor Internal Block Diagram
Rev. A
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EPSON Stylus Photo
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The table below shows W1-2 phase drive sequence at each steps when the rotor of carriage motor
makes one rotation. In the EPSON Stylus Photo, in addition to a function that printing is performed with
W1-2 drive phase, high s peed skip mode which is a function to s kip over the blank from the end of the
printing data to the next data starting point in high speed, can be also performed by 2-2 and 1- 2 phase
drive. W1-2 phase requires 4 times as much steps as 2-2 phase drive, calculating 2-2 phase as standard.
By using this method, it becomes possible to supply constant and stable torque to the motor. As a result, it
also becomes difficult to be influenced by vibration from the printer mechanism during printing.
Table 2-4.Motor Drive Sequence(W1-2.phase drive)
Sequence
Number
Phase a 10a l1a Current
0010+2/3010+2/3
1001+1/3000+1
2X110000+1
3101-1/3000+1
4110-2/3010+2/3
5100-1X01+1/3
6100-11110
7100-1101-1/3
8110-2/3110-2/3
9101-1/3100-1
10X110100-1
11001+1/3100-1
12010+2/3110-2/3
13000+1101-1/3
14000+1X110
15000+1001+2/3
This W1-2 phase drive (or 2W1-2 phase drive) is called Micro-step and is attached with so called
2/3•EVref or 1/3•EVref factor, compared with drive current value (Vref100%) which is supplied at 22phase drive. This Micro-Step allows the rotor to have delicate rotation. In the 2-2 phase drive method, it
is usually
required to take 4-step sequence in order to rotate the rotor once. However, in case of W1-2 phase,
it is required to take 16-step sequence(in the table 2-4, sequence 0•`15) which is 4 times more than
2-2 phase method to do that. Also, in case of 2W1-2 phase drive which can be seen in the Stylus Color
etc., it takes 2-step to rotate the rotor once. The table below shows relation of rotation direction of the rotor
and carriage proceeding direction.
Phase A Phase B
Phase b 10b l1b Current
Duty
Duty
Table 2-5. Relationship Between Rotation Direction and Carriage Operation
Carriage proceeding
direction
HP→80 column direction
80 column→HP direction
Note)
1* Looking from rotor shaft side.
2-
Rotation direction of
Rotor 1*
Clockwise direction 2-2, 1-2, W1-2 phase
Counterclockwise
direction
Drive method Proceeding order of
2-2, 1-2, W1-2 phase
sequence
Sequence No.0→15
Sequence No.15→0
Rev. A
Chapter2 Operating Principles
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The figure below shows carriage mechanism. The print head as a core of the printing mechanism is
installed in the carriage unit. This print head keeps the angle of print head in flexible and adjustable
structure by moving the adjustment lever up and down with the Angular adjustment mechanism.
(Refer to chapter 4 for more details) Also, parallelism adjustment lever is mounted on right side of the
carriage guide shaft and it adjusts parallelism between paper and shaft when this shaft is installed to the
printer mechanism.
After this adjustment is completed, operating the PG adjustment lever makes possible to change the
space between the surface of paper and print head surface into 2 phases; either 1.04mm to 1.94mm. It is
possible to vary the space between the surface of paper feed assembly and the print head by rotating the
axis of carriage guide shaft which itself is decentralized, with the operation of PG lever. This is the
mechanism that user can adjust the appropriate PG value by himself according to the paper thickness or
any other environmental conditions such as paper curl.
Carriage lock mechanism is to prevent the carriage from being left uncapped for a long time because of
vibration during the printer transport or mishandling by the users. If the carriage is left uncapped for a long
time, an ink on the print head surface gradually becomes viscosity. As a result, the nozzle will be unable to
discharge ink. To make matters worse, the nozzle may be completely clogged by the viscosity ink and it
may not be able to return to the normal condition just by the normal cleaning operation. In order to prevent
this, printer goes to carriage lock state at the following conditions.
After Power OFF operation:
If the power is turned off during the printing or any other performance, carriage lock will be
performed in the end after completing initialize operation.
After power ON operation:
After power is turned on and automatic P-On Cleaning(power on cleaning) is performed, then
carriage lock will be performed. The timer IC always counts printer’s power OFF time by using
the power of lithium battery mounted on the C209 main board. P-on cleaning function
automatically selects the cleaning level according to the time which the printer is not in used.
After Eject the paper:
After Load/Eject button is pressed and the paper is ejected, if the data is not input, the printer
performs carriage lock and goes to standby state. However, if the paper is loaded to the printer
inside by Load/Eject button, the printer does not perform the carriage lock operation.
Paper Feed Motor
Eject Roller
Paper guide(Front)
Carriage home position Sensor
PF Roller
Timing Belt
Carriage Unit
Figure 2-8. Carriage Mechanism(Top Viewing)
Front Side
Carriage
Guide Shaft
Carriage Motor
Rear Side
Parallelism
Adjust Lever
Fixing Bush
Rev. A
2-
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