Service manual

5-16 Samsung Electronics
5-1-5 PRINTER
5-1-5-1. GENERAL
It drives inkjet head to print printing data received from the computer or fax data coming through the line. It
roughly consists of head driver, head controller, and the ambient temperature sensor. Fig.6-1-11. Block
Diagram of Printer shows the entire structure.
5-1-5-2. HEAD DRIVER (U19, U20, U23, U24)
This part drives and inks inkjet head. Color inkjet head drives 192 nozzles, while mono inkjet head drives 208
nozzles. Mono inkjet head is composed of 16 groups of 13 nozzles. As to the driver that composes each noz-
zle, 13 row 7-bit driver (U23, U24) selects head address and 16 column 8-bit driver (U19, U20) sends head data.
Head driver converts control signals from MFP controller to +11.75V, the level to be able to drive the head,
and provides them for the inkjet head.
¥ Row Driver Circuit (HD7:U23:U24)
This is a 13-line signal impressed to row drive IC through the output port of MFP controller(/PHGA1 - /PHGA13),
used as an address to drive the head in ink cartridge. Pulse period differs according to head driving frequency. In
1200dpi (in case of Head: 12KHz) mode, timing period is 2.6usec (1/1200Ö16 groups). The signal put in each dri-
ver(window time) is active ÒLÓ, with the biggest driver current max 100mA and output voltage +11.75V.
¥ Column Driver Circuit (HD8:U19,U20)
It is the fire enable pulse of real head. 16 lines are put out as head driving data lines through the output port of MFP
controller (PHOE1 - PHOE16). Enable pulse impressed to the head is put out within window time (Low). It has the
function to move it forward or backward by the register in MFP controller. Besides the output signal may differ in
accordance with the type of head (mono or color). If there is data, printing image is put out at ÒHÓ. If not, it is put
out at ÒLÓ. In case of Babbage head, pulse width is always 1.3use regardless of the type of the head, with the maxi-
mum driving current 400mA and output voltage +11.75V.