Brother International FAX-1010 Service Manual - Page 28

2.4

Sensors

and

Actuators

This

equipment

has

four

photosensors

and

three

mechanical

switches

(two

for

the

FAX1010)

as

described

below.

Sensor

name

Type

Located

on

Document

front

sensor

Document

rear

sensor

Photosensor

(PHI

)

Photosensor

(PH2)

Main

PCB

Main

PCB

Paper

ejection

sensor

Paper

-edge

sensor

Photosensor

(PHI

)

Photosensor

(PH2)

Sensor

PCB

Sensor

PCB

Cover

sensor

Mechanical

switch

(SW1)

Modular

PCB

Ribbon

sensor

Mechanical

switch

(SW1)

Recording

head

Hook

switch

sensor*

Mechanical

switch

(SW1)

Hook

switch

PCB

•

Document

front

sensor

which

detects

the

presence

of

documents.

•

Document

rear

sensor

which

detects

the

leading

and

trailing

edges

of

pages

to

tell

the

control

circuitry

when

the

leading

edge

of

a

new

page

has

reached

the

starting

position

and

when

the

scan

for

that

page

is

over.

•

Paper

ejection

sensor

which

detects

whether

a

paper

jam

has

occurred.

•

Paper

-edge

sensor

which

detects

the

leading

and

trailing

edges

of

paper

and

the

pres-

ence

of

paper

as

well

as

detecting

whether

the

paper

front

cover

is

closed.

These

photosensors

are

of

a

reflection

type

consisting

of

a

light

-emitting

diode

and

a

light-

sensitive

transistor.

Each

of

them

has

an

actuator

separately

arranged

(see

the

next

page),

except

that

the

paper

-edge

sensor

has

two

actuators

for

sensing

the

paper

and

the

paper

front

cover.

When

an

actuator

is

not

activated,

its

white

end

lies

in

the

path

of

light

issued

from

the

light

-emitting

diode

and

reflects

its

light

so

that

the

reflected

light

enters

the

light-

sensitive

transistor.

If

a

document

or

paper

comes

in

so

as

to

activate

the

actuator,

the

actuator's

white

end

goes

out

of

the

light

path

and

no

reflected

light

enters

the

light-sensitive

transistor.

This

way,

the

sensor

detects

the

presence

of

documents

or

paper.

•

Cover

sensor

which

detects

whether

the

recording paper

cover

ASSY

is

closed.

•

Ribbon

sensor

which

detects

whether

the

ink

ribbon

is

loaded.

•

Hook

switch

sensor*

which

detects

whether

the

handset

is

placed

on

the

handset

mount.

The

cover

sensor

has

an

actuator

separately

arranged

(see

page

III

-18).

If

the

actuator

is

activated,

its

lower

end

releases

the

cover

sensor

lever

so

that

the

sensor

signals

the

detec-

tion.

Approx.

0.7

mm

*

Not

provided

on

the

FAX1010

/

Path

of

actuator's

end

4

t

//

\\

.......

--

Glass

I

i

1

Light-

Light

-

emitting

sensitive

diode

transistor

III

-16

Brother International FAX-1010 Service Manual - Page 28

Sensors, Actuators

Page 28 highlights