Samsung SF4500 Theory of Mechanism

Samsung Electronics 7-1

7. Theory of Mechanism

7-1 Scanner Mechanism

7-1-1 Automatic Document Feeder

(ADF) Mechanism

The automatic document feeder, consisting of various rollers, ADF rubber pad, and springs, automatically separates and feeds the pages of a document over the scanning area and stacks them on the document exit tray.

Documents up to 30 pages can be placed in the automatic document feeder for scanning. The leading edge of the document will move the document detect sensor lever when the operator slides the stack into the ADF. The scan motor starts to rotate when the document detect sensor has detected the leading edge of the document. The ADF roller feeds the first page of the document into the feeder.

The scan motor is stopped when the leading edge of the page actuates the document scan sensor. The page is now in the scan position.

The ADF rubber prevents multiple sheets from being feed. Aspring provides forces that the pad places on the document pages for proper separation.

The scan motor is turned on when the machine is ready to scan the document and drives the feed roller at a speed determined by the resolution selected. The scan motor is stopped after a set period of time when the trailing edge of the page releases the document scan sensor. If another page is detected as the tailing edge of the page releases the document scan sensor, the next page will be fed to the scan position. The exit roller pushes the page out onto the document exit tray where it is stacked.

7-1-2 Contact Image Sensor (CIS)

The contact image sensor unit consist of LEDs, rod lens array, and a photo sensor. The LEDs illuminate the document to be scanned when the leading edge is detected by the document scan sensor. The LEDs turn off when the document exits the scanner mechanism.

The LEDs illuminate the document to obtain an image from the document through the rod lens array, where the image is translated into voltage levels.

7-1-3 Document Sensors

There are two document sensors in the scanner mechanism; the document detect and the document scan sensor. The document detect sensor, detects whether or not a document is loaded, and the document scan sensor detects the scan position of the document.

The scanner mechanism consists of components which feed, scan, and eject the documents that are to be copied or transmitted to a remote facsimile unit. These components and their functions are explained below.

Samsung Electronics 7-2

7-2 Printer Mechanism

7-2-1 Paper Feed Mechanism

This mechanism consists of the automatic sheet feeder (ASF), feed roller ass’y, line feed motor, and gear ass’y to move the paper in and out of the printer.

When paper is fed in the printer, the line feed motor rotates briefly counterclockwise then regularly rotates clockwise to move the paper inside the printer.

The stopper clutch transfers or interrupt power to the gear clutch according to the direction of motor rotation.

When a power is supplied to the gear clutch, it transfers the power to the pickup roller in ASF.

When the line feed motor rotates clockwise and power is transferred to the gear clutch, the power pulls the paper in the printer.

When the line feed motor rotates clockwise, the stopper clutch interrupt power so that the gear clutch is in idle state. The power is transferred to the idle gear and the paper is pulled in the printer and out of the printer.

7-2-2 Home Ass’y

When capping is released, the print cartridge carrier moves left and wipe the bottom of ink nozzle. After wiping it, the carrier rib pushes the rib in the dotted round as shown in the figure below. The home ass’y converts into standby mode.

Feed roller gear

Idle gear 1

Idle gear 2

Idle gear 3

Stopper clutch

Latchet clutch

Gear clutch

Hub clutchHub clutch

Idle gear 4

Motor