KONICA 1312 Service Manual ech6

Chapter 6 Mechanism

6-1. Copy process ....................................................... 6-1

6-2. Front cross-section (Main mechanism

parts layout drawing) .......................................... 6-3

6-3. Drive conveyance system diagram .................... 6-4

6-1. Copy process

Chapter 6 Mechanism

2. Side erase

1. Charging

3. Exposure

4. Development

Photosensitive
OPC drum

5.Transfer

5.Separation 5.Conveyance

8.Paper feed cassette

1. Charging

A high voltage of -4 to -5.5KV, output from the high
voltage PCB (UNITHV), is applied on the charge
corona unit. The grid mesh between the
photosensitive OPC drum and charger is grounded via
a 780V Zenner diode, keeping the surface of the
photosensitive drum constant at -720V.

7.Main erase

7.Cleaning

7.Toner collection

6.Fixing

4. Development

1) The toner contained in the developer is positively
charged when agitated. The charged toner is
developed (magnetic brush method) when con­tacted against the OPC drum by the carrier (ferrite)
and magnet roller. The toner adheres only at the
sections of the OPC drum where there is an image,
and creates a visible image. There is a slight
negative charge even at the sections with no image
(white sections), and some toner will adhere. The
bias voltage -170V, output from the high voltage
PCB (UNITHV) is applied on the magnet roller to
prevent this adhesion.

2. Side erase

The non-image area such as the edges during reduc­tion copy, of the OPC drum surface after charging is
discharged with the side erase lamp.

Side erase lamp

Reduction
image area

Non-image area

3. Exposure

The light irradiated from the exposure lamp exposes the
photosensitive surface via the six mirrors and lens.

Document table glass

No. 4 mirror

No. 5 mirror

No. 6 mirror

Slit

OPC drum

Erase light

OPC drum

Document (back side is image)

Exposure

No. 1 mirror

lamp

No. 1 scanner

No. 2 scanner

No. 2 mirror

No. 3 mirror

Magnet roller

Toner

OPC drum

Carrier

2) The density of the toner contained in the developer
is kept constant by the toner sensor (magnetic
sensor). When the toner sensor detects a low
density, the supply screw provided at the bottom of
the toner box rotates, and the toner is supplied into
the developer.

Toner

Developer

Supply screw

Toner sensor

6-1