Driving Specifications - Epson Stylus Photo RX700 Service Manual

EPSON Stylus Photo RX700

2.2.3.4 Driving Specifications

Basic control operation
The PG setting in several stages for the Carriage is achieved by moving the CR
Guide Shafts up and down with the DC motor while monitoring with the position
sensors. The control of the DC motor is referred to as Auto PG control (APG
control). The basic operation to realize this control is as follows:
<Setting Control>
To move the CR Guide Shafts from the current PG position to a designated PG position, the DC
1
motor is driven by energization (Duty) according to the time setting, slowed down by receiving
the signal from the sensor 1, and stopped within the PG setting range.
<Reset Control>
By unidirectional energization according to the time setting, the DC motor is driven and stopped
2
at the stopper position. Then PG positions are counted until the Position 1 is reached. Arrival at
the Position 1 is determined when the number of the PG positions is equal to the theoretical value.
APG control operation mode
There are five PG positions, which are determined by a continuous cam profile. Switching
1
between these positions is permitted in sequence: posi.1
The sensor 1 outputs the H and L signals when each PG position area and each area between
2
adjacent positions are detected, respectively. (See the table below for operation modes.)
To set and recognize each PG position area, rotate the motor in the posi.5 direction of the sensor
1 until it is stopped by the stopper. Then rotate the motor back in the posi.1 direction. The five
position areas are recognized in sequence; posi.5
3 this point, posi.1 is established as the first position. This position flag continues this recognition
of the positions until setting of the positions is newly made by a higher sequence.
Each PG position area is set when it is recognized that the signal from the sensor 1 changes as L
→ →
H (or H L).
Sensor 1 output
Low
PG schematic diagram
End position posi.1 posi.1-2 posi.2
Starting position PG–
posi.1
posi.2
Setting
posi.3
control
posi.4
posi.5
Position not
Reset control
identified
Operating Principles
⇔ ⇔ ⇔
posi.2 posi.3 posi.4
⇒ ⇒ ⇒ ⇒
posi.4 posi.3 posi.2
mark shows each pair of positions
←
Reference edge
where basic control takes place.
posi.2-3 posi.3 posi.3-4 posi.4 posi.4-5 posi.5
PG typ PG+ PG++
Mechanism Operating Principles
Figure 2-13 below shows the relationship between the PG positions and the outputs of
the sensor 1 as well as major applications of the PG positions.
⇔
posi.5
posi.1. At
High
Reduction gear ratio between PG motor ~ composite gear (flag) = 1/91.93
Reduction gear ratio between PG motor ~ CR Guide Shaft = 1/71.04
Reduction gear ratio between PG motor ~ Release Shaft = 1/73.54
• CR Guide Shaft turning angle = Composite gear turning angle
* In any PG changing area, the CR Guide Shafts move up and down (the cam gear rotates). Therefore, the
Release
above conversion equation cannot be used.
• Release Shaft turning angle = Composite gear turning angle
Figure 2-13. PG Positions and Sensor Outputs, and Major Applications
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