Appendix (Mechanism Operating Principles); Transport Mechanism; Head Feeding System - Samsung SRP-275 Service Manual

8. Appendix (Mechanism operating principles)

The printer mechanism of the SRP-275 consists of the following component mechanisms:

• Transport mechanism

• Printing mechanism
• Detection mechanism
• Auto cutter mechanism
• Easy paper loading mechanism
These components are described in detail in the following sections.
8-1 Transport mechanism

8-1-1 Head feeding system

This printer is using DC24V PM Type Stepping motor. As shown in figure, the motor section consists of the
motor, motor speed control IC, motor drive/brake circuit and motor speed interface.
When the HF(Head Feed) motor is driven and the HF motor pinion is moved in the direction of arrow B, the
rotational power is conveyed to the belt drive pulley, then the belt. Next the Carriage head ass'y, which is
fixed to the belt, moved in the direction of arrow B.
When the HF motor pinion is rotated in the direction of arrow A, the Carriage head ass'y is moved in the
direction of arrow A.
Rev. 2.00
Belt-round
Head
Pulley
Carriage head ass'y
HEAD_PA
6
HEAD_PAn
5
HEAD_PB
17
HEAD_PBn
16
VCC_5V
2
13
R2
47K 1608
VCC_5V
R3
C8 47K 1608
470p 1608
C9
470p 1608
VCC_5V
R8
680 1% 1608
R9
27 1% 1608
R11
HEAD_HOLD Q1 R10
MMBT2222ALT1/ SOT23 100 1% 1608
1K 1608
Pinion-HF-motor
A B
A
A
B
Ass'y-gear-pulley
VCC_24V VCC_24V
C1 C2
100n 1608 100n 1608
U1
INA
INA
1
OUTA
INB
SLA7024M
8
OUTA
INB
11
OUTB
18
OUTB
Td_A
Td_B
C6 C7
1n 1608 1n 1608
R4 R5
510 1% 1608 510 1% 1608
R6 R7
1 1W 6432 1 1W 6432
- 128 -
SRP-275
B
HEAD_A
C4
22p 1608
HEAD_An
HEAD_B
C5
22p 1608
HEAD_Bn