Xerox EP0033574 User Manual

ê

19

Europâisches

European

Office

Patent Office

européen

Patentamt

des brevets

(îî)

Publication

number:

O

Bl

033

574

(12)

Date of

©

@

Application

Date

@

Electrical

(54)

intensifier

(§)

Priority:

Date of

@

12.08.81 Bulletin 81/32

Publication of the

(45)

28.09.83

publication

number:

offiling:

02.02.81

power

tube.

04.02.80 GB 8003613

publication

Bulletin 83/39

EUROPEAN PATENT

of

patent

81200119.6

supply

arrangement

of

application:

of

grant

spécification:

the

patent:

28.09.83

for

image

SPECIFICATION

H

01

J

Int. Cl.3:

©

intensifier tubes and combination thereof with

@

Proprietor: ASSOCIATED

Arundel London WC2R 3DT GB

® (73)

Proprietor: Groenewoudseweg NL-5621 BA Eindhoven BE

(84)

DE FR NL SE

PHILIPS ELECTRONIC AND

Great

N.V.

29/98, H

INDUSTRIES Court 8 Arundel

(GB)

Philips'

Gloeilampenfabrieken

1

(NL)

01 J

LIMITED

Street

an

31/50

image

@ Designated

BE DE FR GBNLSE

Références cited:

(56)

GB

A

1 340

-

- A

-

notice

(Art.

3 694 3 739 178

a

99(1)

US US -A- US -A -3 848 US-A-4056

Note: Within give

be filed in paid.

Contracting

092 659

123 721

nine

the

to

written reasoned

European

States:

months

European

from

patent

the

publication

Patent Office of

statement.

convention).

It

Courier

of

the mention

opposition

shall

not

Press,

Leamington

@

(74)

the

to

be deemed

Inventor: c/o. Mullard Limited Mitcham,

Représentative: Philips Department London WC1

of

the

European

to

Spa,

McDonald,

Surrey

Electronic and Associated Ind.

grant

have been

England.

Boxall,

Mullard House

E

7HD (GB)

the

of

granted.

patent

filed until the

Richard

New Road

CR4 4XY

Robin John

European

Notice of

Lewis Cameron

(GB)

et al,

Ltd. Patent

Torrington

patent,

any person may opposition

opposition

fee has been

Place

shall

The

present

power imaging fier device

description image

which window electronic photocathode. focusing electron

modifying microchannel

fying entrant window

opposite for fied

plate. image

number of

a to channel

supply respect

channel

1.0

input focus KV, electrode

supply respect

channel plate

into voltage

at of the

potential electrode of

phosphor the focus correction electrode float variations

Generally form fit

envelope is

ponents tion

intensifier tubes examples

block schematic circuit

1 of the

supply

intensifier tube.

Such tubes

there is

the electronic

producing

electronic

A

intensifier tube is

variable

the

input

is minus

KV,

electrode correction electrode

10 nA measured

is

variable

a

100

a

supplied

instant

any

photocathode,

hollow

a

the

on

possible having regard

between

Various

The

two

invention relates

tube

having a photocathode

side

to plate,

to

image

accompanying drawings.

arrangement

employing

which

will be

image

the

electron

image, a

the

thereof,

having

exit

the

power

substantially

potential

and

plate.

the

nA measured with

10

the

of

plus

the

plate,

MΩ

difference

the microchannel

screen

in

the

cylindrical

to

provide

used and the

the

power

will be described

examples

tube for

referred

comprise

may

arranged a

of

A

focusing

image

a

image leaving

the conical anode

output

depends

power

cylindrical

light impinging on

conical anode electrode for

focus correction electrode for

intensifier

image

and

phosphor

a

side of the microchannel

visible

supply

difference which is

output

Generally

2.0

KV,

electrode

input

the

of

with

microchannel

5

KV,

and

across

voltage

load

across

intensifier tube

fixed whilst the

is

the

channel

the

supply

as

voltage

high

supplies are

for

microchannel intensi-

a

hereinafter

to

fibre

beam

and

of the

electrodes of the micro-

microchannel

70 nA measured with

electrode

on

compact an

need

known of

diagram

electron

impinging on fibre

a

screen

image

is

between the

conical

from the

the microchannel

for

use

required to produce

fixed D.C.

the

120 nA measured with

supply

respect

plate,

the microchannel

of

plus

supplied.

microchannel

the

photometric gain

is

shell

which

surface of the

the

to

outputs.

for

with

the

of

to

an

convenience of

an

for

plate

with

photocathode

of the micro-

supply

respect

of

200

required.

plate

anode

plate

encapsulated

number of

provide

use

reference

shown

known

electrical

an

electronic

as an

envelope

optic input

providing an

inverting

optic

voltages

minus

is

to

the

the micro-

to The

potentials

assembly as

with

which

beam,

for

ampli-

output

disposed

plate

ampli-

such

applied

is

plus

to

plate,

the

input

screen

1000

exact

plate

output

and

and the

with

voltage.

is

close

a

tube

com-

insula-

image

two

to

in

Figure

power

the

and

the the

1.0

The

the

in

an

V

of

to

supplies example whilst the oscillators a ferences the circuits

oscillator which output

peak. tioned D.C. conical and

a

Generally voltage

and 22. description

derived from its

19

(ABC) oscillator 26 which alternating voltage.

sary the

tion derived from the 5 KV DC

32. to variable

plate nected

input CPI

plies 13, float with

asynchronous

arises oscillator 26 inductance and

ary the

when the quency

and which which

harmonic

oscillators sive.

second and 26 have levels. However within

has specialized

order

10, forced

quency. current to

differ from each other

has

asynchronous

second

link between

In

and 21. An

screen

The

the channel

In

of the

frequency

The

26 which

10, 26,

Figure

the

to

levels.

output

"pulling"

1 the

voltage

This

anode,

screen

multiplier

circuit 24

maintain

output

D.C.

of

to

CPI and

the

because of

also

pulling produces is

problem example

reasonable

a

been found

reduce

to

of the order

voltage

voltages

the

of

these

voltages

However for the

each

of these

a

over a

To this

of the oscillator 26 is

plate

voltage across

the

tube 36. The

outputs

channel

is also

15 and

the CPI

of

case

oscillators

being

stray

step-up

of

output

changes causing

between the oscillators 10 and 26

unacceptable

beating

26

10,

in

the

in

component

the

will

operate

Since

the

batteries

power

respective

of

example

the broken line 11

them.

voltage.

operation

Apart

are substantially

oscillator

produces a

is used

for the

focus correction electrode

an image

are provided by a

having

outputs

automatic

is

provided to

produces a

The ABC constant wide

range

end,

an

supply

identified

plate

connected

that their

19

so

the first

the

output

variable. Due

capacitance

transformer which controls

voltage changes,

an

to

and

be

can

flicker

which the

frequency

same

order

performance

that

selection is

pulling

consume

other

at

supply,

in that the

oscillators

has

synchronised

indicating

from

these dif-

the

10

is

high voltage

a

fixed

of 1 KV

to

photocathode,

intensifier tube 36.

outputs

D.C.

brightness

circuit 24 is

brightness

ABC

supply

28

the microchannel

supply

example

10,

of

instability

viewer. Whilst the

a pulling controlled,

is

overcome

two

be able

to

an expensive

of the

excessive

than

are

it is

alternating

peak-to-

provide

convenience of

of

which

as output

to

the oscillator

harmonic

their

the

14, 16,

is shown

supply

variable

input

sense

26,

voltage

specification

two

used

necessary

13, 15,

control

image on

illumina-

signal

the line

21

on

connected

supplies

28 is

channel

CPO. The

D.C.

the

outputs

which

a problem

the

to

the second-

in

the fre-

beating

or

between

is

it

oscillators

all

for

to

operate

required

oscillators

power

natural fre-

to

first

26

10,

same.

men-

the

high

20

be

to

control

the

output neces-

con-

plate

sup-

can

uses

of the

large

26,

flicker

the

expen-

the

by

10

light

and

supply

that

is

a

it

in

if

the

power

tube proper

utilise consequently

bulky.

It is

provide intensifier

tion,

ponents.

According to

provided

image image comprising

(ABC) circuit be

supplied fier circuit includes

comprising a current

maximum thermal breakdown is avoided.

By

series

a be constructed

Consequently frequency beating ponents

the series

of tion is reduced but the size of supply

In back transistor. The

reference

a proportional to fore nected

means means amplifier. By making ABC circuit direct time of the ABC circuit

additional

no the tube from the

bright light on

British discloses in image tor Walton monitored and is used produced tions in resistance)

the

to order between the

plate multiplier the

consumption

be

kept

operation.

a large

the

an object

a

power

tube

flicker and

no

a

power

intensifier

an

for

to

plate,

proportional

whose

input

characterized

transistor

less

gain

collector

runaway

virtue of

regulating

interference

or pulling.

is reduced and

regulating

necessary,

is smaller.

embodiment

an

amplifier

voltage

the

to

and automatic

may

Patent

Figures

intensifier

output

multiplier.

by

a

light intensity

of

output

to

vary

and

the

to

there

be connected

circuits

a vacuum photo

electrode

the

output

minimum

Both

these

number

encapsulated

the

of

supply

producing

the

is connected amplifier

the

voltage multiplier.

the

light emitting

and the

for

which

has

a

the

present

supply

tube

having

plate,

automatic

microchannel

series

a

operated

than

unity

current

which would lead

ABC circuit

circuit,

having

will be

The overall number of

apart

circuit

therefore

the

of

and

screen current,

its

to

brightness,

brightness

the

current

are

effects of sudden

photocathode.

Specification

2

and

system

is

applied

The

vary

potential

electrode of

screen

electrodes of the channel

the

of

image

known

of

components

present

high voltage image

a

provides

small

invention

arrangement

the

brightness

variable

a

in that said control

regulating

and

that the risk of

a

power

single

a

no problems

due

from the

no

not

encapsulated

the ABC circuit

to

has

two

second for

a

to

current

ones,

is

sufficiently

necessary

3

having

screen

to

diode. These varia-

the

diode connected

the channel

of

difference

but also between

intensifier

consistent

examples

power

number of

a

controlling

the

a

vary

supply

invention

good

regula-

there

for

microchannel

power

image

in class

at

to

special

only

inputs,

control

the feedback

the

channel

single

a

to

conductivity

supply

control

voltage

intensi-

circuit

A

such

second

to

supply can

oscillator.

due

oscillators

transistor

selec-

is the

power

a

base of

one

a voltage

and

there-

which is

Gain

setting setting

in the

paths

response

fast that

to

protect

flashes

1,340,092

oscilla-

Cockroft

a

current

the

plate

not

channel

the

a

with

and

is

to

com-

is

an

to

with

low

such

to

com-

cost

feed-

the

for

con-

of

plate

is

light

(or

in

only

plate multiplier;

tube and

the the

input

multiplier

is

not

invention vacuum

straints

been manufacture would because Furthermore the (M.T.F.), contrast adversely of the

voltage

channel embodiment

put

changing

tion conical anode

electron tial difference

voltage

to

only

photocell

of

such

a

type

produced

for

change

between the

plate

electrode/screen

maintained

in the embodiment

more

the

voltages applied

allowed

plier

intensifier tube.

by

of made

embodiment ABC

ABC

power present type

voltage multiplier the series

prises a

which

ing voltage ing voltage.

derive the D.C. KV, on

These

high voltage multiplier or convenience of

14, 16,

nected

21.

to

be varied

to

without

The

present

of

way

of

6

the Figure an image

in accordance with the

Figure

system

Figure

system,

Figure

supply

series

Figure

Referring

single high voltage

produces a

The 1.0 KV

10

nA;

the

outputs

voltages

20 and

to

the

potential

between the

electrode

fixed. Such

being

different

but also

the

power

of

photocell

of the small

which is

the cited

at

higher spatial

of the

constant

the tube

float with the

multiplier

example

accompanying drawings,

2 is

a

intensifier tube and

3 is

a

of the

of

4 is

a

5

is

unit made

invention

voltage multiplier,

6

shows

multiplier

to

and

-1

a respective

from

requires

of

size

a

supply.

in

quantity

inherently

modulation transfer

measurement

a

system,

in

focusing

multiplier

across

invention will

Figure

output

present

focusing

and distortion

thus

the by varying affecting

with

block schematic

schematic circuit

series

Figure

simplified

complete

having a

an

which

in

2,

KV

1

KV

1.1

a

alternating voltage

outputs

10

KV,

14, 16,

be

may

description

22

will

differences

photocathode

of the

if

ever

and the

potential

and hence the

input

permitting

reference to

2,

in

example

can

Figure

the

peak-to-peak

of

Na and

20 and

derived

be shown

supply

channel

regulation

a

that of the

low

leakage

a

required by

As far

produced,

and therefore its

numbers concerned.

can

frequencies

due

to

electrode

invention

is avoided. Further-

the

of

the

to

electrode of the

channel

its

the

now

present

regulator

circuit

accordance

Cockroft Walton

and

be used in

5.

power

oscillator

-2

KV,

22, respectively.

separate

each

the

is

as

be

expensive

function

of loss

be effected

because

variations in

screen.

the

difference is

present photocathode,

corrector

the

plate

electrode

input

M.T.F.

be

described,

Figures

wherein:

circuit

diagram

a

power

invention,

diagram

used in

diagram

with the

of

a

supply

circuit

alternat-

is

130 nA

KV 70 Na

+6.1

using a single

supplies.

of

the

being

as

13, 15,

across

and

plate

system

present

high

con-

known,

has

not

of

the

In

an

out-

risk of

inven-

are

poten-

multi-

of the

2

supply

of

an

the

of

parallel

of

place

com-

18

used

to

+1

For

outputs

con-

19 and

a

The 1.1

supply

which

30 supply

the

one

circuit signal

line 32. The

the

connected supplies voltages can output. outputs

200

order of

the

In order

good

series

a

in

Figure comprises example a emitter lector

KV

1.1

CPO

42

rail

transistor 38 and the

the nected.

having

the base

amplifier potential resistor resistor between reference second

variation in the

any cause varied in

quickly

The important controlling a voltage

emitter temperature

The

leakage. leakage

attainable

It has

mercially rated

tions. A transistor size conditions

mode"

rating

conditions.

Transistor

mechanisms

any

to

tor carriers

rapidly

KV

peak-to-peak

is connected

be

may

is connected

30

hand

24

on

is derived

to

13,

The

potential

DC

is

a

and 1.1

to

regulation

regulator

3. This

an

selected BUX 87

is connected

is connected via

34

rail

output.

selection

at

and has

specific

The CPI

which the

to

The

output

high input impedance

of the transistor

44

is connected

divider formed

48

50. The the rail

voltage

input

the

conductivity

such

restored

selection of the

because it

of

(VCE)

range

Leakage

current

at

been

available transistors

VCE≥900

a

prevailing

power

falls

to

obtaining

transistor

emitter

suddenly

increasing

via

and

other

the

from

output

CPI

the

15 and 19

float with

voltage

KV

with

100 MS2.

provide a

the ABC circuit

of

circuit

NPN

which is also connected

of

and

a

potential

42 and

line

of the

manner

a

that

to

least

at

(typically

parameters

is

will affect

output

found that there

V under

such

rating

V CE

supply

450

V under

ratings are governed by

voltage

start

alternating

KV D.C.

+1.1

to

a

voltage multiplier.

a

the

to

a

the 6.1 KV

of the ABC circuit output

the

across

which

an

flicker-free

as

series

power

to

ground

a

output

junction

a

presettable

52 is connected

amplifier

voltage

of

set.

type

must between 900

important

CPI.

as

of

in

a

(pulsed operation),

within design

at

the

CPO

line

34

hand.

so

voltage on

output

shown

load

resistor

feedback

38. to

by a

divider is

ground.

the transistor

that the

V

-60°C are

the minimum

steady

BUX

1000

so-called

steady

which the

to increase,

conductivity

to

ABC

An

supply

and

to

that their

the CPI

can

vary

impedance

image

24

schematically

regulating

transistor

BUW 85

or

of the

a tapping

on

of

whose col-

and

resistor

is connected

collector of

40

amplifier

is connected

One

input

fixed

lower

A

44. In the rail

transistor

be

capable

collector and

the

over

to

VCEI

because

are no com-

of suitable size

state

87 is of suitable

V

under those

"switched-

state

the transistor. For

is

there

current

supply

The

output

comprises

high

connected

1.5 V D.C.

voltage

the failure

on

ABC

the

sense

21

on

24

is

DC

the

output

the CPI

CPO

and

between

of

and

circuit

for

38,

whose

40

to

the

to

is

con-

44

to

of the

46 of

value value

to

operation

42

will

38

be

to

38

is

of

required

+60°C).

size and

high

a

voltage

condi-

but

the

(class

A)

collec-

a

current

thereby

of the

is

transistor. This

breakdown". Once avalanche through heating catastrophic damage.

"second

mum

tor

ensured that second breakdown This 87

voltage.

is effected emitter shown

emitter voltage

current

conditions

87

a

supply

circuit 24 values of the

the

this connection it the

temperature, from

line 32

meter

P-channel enhancement field

(FET) the

control

FET 56 is

transistor

fier 44 is formed

enhancement

is

tor

52

resistor

divider

tor

comprises

between the rail

fixed

tapping

50B and 50B is plate voltage. across standardise can low turned 56

on increases the

it

of the

breakdown".

It

has

current

by

means

permits

BUW

or

The

resistance. It is

in

resistance appears

gain

BUW 85 is

or

Hence

with

Figure

particular

resistance of

400 MΩ

The

screen

is connected

53

56. The

operating

circuit 24.

connected between

38 and

is connected

60. The

is

58.

In

value resistor

46 and the

connected between

ground.

adjusted

the channel

be varied between 200 and

light

off. As the

conduction increases

the base of

mechanism is called

the transistor

condition,

can quickly

semiconductor which

been found

that

of

the

use

85

up

voltage

the

by

Figures

across

is

less

the avalanche

simple,

a

single

a

4 shows

including

components

microchannel

typical

a

to

current (I

via

resistor 54 and

a

potentiometer

level

connected between

38 and

FET

ground.

connected this

embodiment the

high

a

42

The

to

The

the load.

level

operation

voltage

the

rise,

This mechanism

that

by limiting

flow

can

the resistor 40

of

transistor such

a

its

avalanche

to

which

at

current

3,

greater

one

should be borne in

a

3 CΩ.

The source-drain

ground.

58

to

tapping

value resistor

50A

wiper

load resistor

light

gain

feature of

a

4

and 5 that the base-

is

<1000 Q

the

than

breakdown of the BUX

compact

oscillator

embodiment

series

a

channel

resistance

screen)

the

to

of the automatic

by

whose source-drain

the

The reference

the

to

and the

connected

wiper

of

the maximum channel

set

plate

channel

The

level

reducing

transistor

the

of line

"avalance

is in the

current

causing

through

does

avalanche

and

transistor and

unity.

than 1000 V.

and

can

regulator.

selected

plate

variation

tap

to

effect transistor

53

serves

the

The

feedback

another

base

amplifier

46

of the

gate

potential

tapping

of

a

6V

a

supply

the

40 is connected

and is

the FET 56 will

increases,

which reduces

42,

passing

local

causes

is called

the maxi-

the transis-

it

can

not

occur.

as

breakdown

occurs

the base

the circuits

when

a high

Under these

reliable

being

or of

the

of the transis-

48

potentiometer

1100 V.

power

built.

be

of the

depend

used.

mind that

varies with

ABC

sense

a potentio-

gate

to adjust

brightness

of the

path

base of the

ampli-

P-channel

voltage

44 via

potential

divider

connected

46 and

between

rail

provided

plate voltage

the

38,

In

the

voltage

which

over-

be

BUX

to

the

ABC

The

on

In

being

of

an

path

line

the

62

to

the

be

FET

a