Epson DFX-8500 service manual ‰Deceleration control, Current speed SP3, SP3 Speed

DFX-8500

‰￿Deceleration control:

Deceleration control provides smooth deceleration and prevents rapid vibration.

The duty data for deceleration control is determined for each printing mode. Pulse width modulation (PWM) determines each printing mode.

Current speed - SP3

1.The printer uses Deceleration driving mode 2, based on the duty data, and the rest of the time, it uses Deceleration driving mode 1.

2.During this time the control circuit measures time periods using the encoder signal, and controls the following:

∙When duty data becomes Dutymin1 before the carriage speed reaches SP3.

∙When the carriage speed reaches SP3 before duty data becomes Dutymin1, the next sequence (SP3 - Speed 0) takes effect.

SP3 - Speed 0

1.When the carriage speed reaches SP3, Deceleration driving mode 3 takes effect. This control method is the inverse-continuity break method.

2.During this time, the control circuit measures time periods using the encoder signal. When the rising edge of next pulse is not detected after 1.5 seconds, Deceleration driving mode 1 takes effect and the control circuit controls short-break.

	SPref
Deceleration Curve
	SP3
	0
	1	2	3
Signal	Deceleration 2
	or
Control	Deceleration 1
			Deceleration 3

PWM Perodic Time

Note: 1, 2, and 3 indicate the PWM control section number.

Figure 2-22. CR Motor Drive Circuit Block Diagram

2-28 Rev. B