Epson Stylus Color 760, Service Manual

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EPSON Stylus COLOR 760 Revision C
Operating Principles Overview 31
2.1.1.3 Carriage Mechanism
The carriage mechanism for the Stylus COLOR 760 is mostly the same as for
other ink jet printers except it is driven by a DC motor. See the table below for
the carriage motor specifications.
Table 2-2. Carriage Motor Specification
Unlike a stepping motor, the DC motor that drives the carriage can not detect
the current carriage position by referring to the pulses given. Therefore, a linear
scale is attached along the carriage operation range to enable the printer to
mechanically detect the carriage position. (Same as the Stylus COLOR 900)
The linear scale is also used to produce the print timing signal (PTS signal), to
which the printer refers to for a correct ink ejection timing. For detailed
information on the CR motor control circuit, see Section 2.2.
Figure 2-5. Carriage Mechanism (Top view)
The printhead, a core of the printing mechanism, is stored in the carriage unit.
When the adjustment lever is moved up and down, this printhead is maintained
tilt in a flexible and adjustable structure by the tilt adjustment mechanism. Also,
the parallelism adjustment levers, mounted on the left and right sides of the
carriage guide shaft, are used to set the carriage guide shaft parallel to the
platen when the shaft has been installed to the printer mechanism. After this
adjustment is completed, moving the PG adjustment lever sets the distance
between the platen surface and the printhead surface to one of two
possibilities: 1.14 mm or 1.84mm. You can change the distance by rotating the
shafts of the carriage guide shaft which itself is decentralized, with the
operation of PG lever. This is the mechanism that the user can use to adjust
the appropriate PG value according to the printing result or any other
environmental conditions such as paper thickness.
.
Items Specifications
Type DC Motor with brush
Drive Voltage +42 V +/- 5%(DRV IC voltage)
Internal Resistance 29.2 ohms +/- 25%
Inductance 30.8 mH +/- 25%
Drive Method Constant Current Chopping
Driver IC LB1947
PF Roller
Timing Belt
Liner Scale for
CR motor
CR unit