U.S. Patent 2,096,106, entitled "Transforming pressure variations into electrical variations" issued 1937.

8/16/2019 U.S. Patent 2,096,106, entitled "Transforming pressure variations into electrical variations" issued 1937.

1/9

Oct. 1 9 , 1937. A . GUERBILSKY 2,096,106

METHOD

AND APPARATUS

FOR TRANSFORMING

PRESSURE

VARIATIONS INTO ELECTRICKL VARIATIONS

Filed May

16, 1 9 5 3 ; ? ~ _ - - 4 Sheets-Sheet

1

F i g . 1

,6

In enzovqs


2/9

Oct. 19, 1937.

-

‘ A . GIUERBILSKY ~ 2,096,106

METHOD AND APPARATUS FOR TRANSFORMING PRESSURE

VARIATIONS I N T O ELECTRLCAL VARIATIONS

Filed

May 1 6 , 1 9 5 3 4 Sheets-Sheet 2

1 7 1 9 . 3

E l l ?

M 5 ?


3/9


4/9

O c t . 1 9 , 1 9 3 7 .

A .

GU-ERBILSKY

2,096,106

METHOD AND APPARATUS FOR TRANSFORMING PRESSURE

V A R I A T I O N S I N T O ‘ E L E C T R I C A L V A H I A T L O NS

Filed May 1 6 ,

7 1 9 3 3 4

Sheets-Sheet

4


5/9

P a t e n t e d

O c t .

19,

1 9 3 7

U N I T E D

S T A T E S

s n a r e s

2 , 6 9 6 , 1 0 6

‘ P A T E N T

O F F I C E

_METHOD AND APPARATUS FOR TRANS

FORMING PRESSURE

V A B I A TI O N S I N T O

ELECTRICAL VARIATIONS

A l e x i s G u e r b i l s k y , P a r i s , F r a n c e

A p p l i c a t i o n May 1 c , 1 9 3 3 , S e r i a l

N o .

6 7 1 , 3 2 7

,

In Belgium

May 1 8 ,

1932

4

C l a i m s . ( 0 1 . 119-10014)

My n v e n t i o n r e l a t e s t o methods and

a p p a r a t u s m o d i f i c a t i o n s ‘

o f t h e s e - o s c i l l a t i o n s . - : T h e s e modi?-

i n

which

pressure

v a r i a t i o n s are transformed i n t o

e l e c t r i c

v a r i a t i o n s ,

e i t h e r f o r

measurement,

o b

s e r v a t i o n , o r

r e c o r d i n g

p u r p o s e s , or

i n

o r d e r

t o

o p e r a t e

c e r t a i n

a p p a r a t u s r e s p o n s i v e t o s a i d p r e s

sure v a r i a t i o n s .

The c h i e f

o b j e c t

o f my

n v e n t i o n

i s t o

p r o v i d e

_a

method and apparatus

o f : t h e kind above r e

‘ f e r r e d

t o by means o f

which

the v a r i a t i o n s o f

pressure are

transformed

into variations

o f

an

e l e c t r i c c u r r e n t p e r m i t t i n g a c c u r a t e measure

G I

‘

ment,

observation,

o r

recording of

the

pressure, ‘

o r e ? l c i e n t action o n

the apparatus

t o

be con

trolled b y said pressure.

To

t h i s e f f e c t ,

a c c o r d i n g t o

my i n v e n t i o n .

I

v i c e ,

i n

t h e ? e l d pro duced by an e l e c t r i c c u r r e n t ,

tuned to resonance

w i t h .

t h e

c r y s t a l ,

s o

t h a t s a i d

c r y s t a l , o r

e q u i v a l e n t

d e v i c e v i b r a t e s ,

and

I

then

a p p l y t o one

o r s e v e r a l

f a c e s o f

s a i d

c r y s t a l t h e

p r e s s u r e ' t h a t

i s ' t o

be

measured,

o b s e r v e d , o r

r e c o r d e d , o r

t h a t

i s

t o

c o n t r o l t h e o p e r a t i o n ‘

o f

a

g i v e n

a p p a r a t u s . I

then u t i l i z e

t h e ‘ .

v a r i a t i o n s

t h a t

t a k e p l a c e i n

t h e c u r r e n t

o f s a i d c i r c u i t

o r

o f

another

c i r c u i t c o u p l e d with

t h e

‘ c r y s t a l

o r

2 5

e q u i v a l e n t d e v i c e i n

consequence

o f t h e

v a r i a t i o n s

o f t h e p r e s s u r e , e i t h e r d i r e c t l y

o r

i n d i r e c t l y ,

f o r

m e a s u r i n g , o b s e r v i n g , o r

r e c o r d i n g s a i d v a r i a

t i o n s

o f p r e s s u r e , . o r f o r o p e r a t i n g

t h e a p p a r a t u s

20

t h a t

i s t o

w o r k

i n

accordance

with s a i d

v a r i a t i o n s

so o f

p r e s s u r e .

T h e ’

p i e z o - e l e c t r i c

c r y s t a l may b e

mounted i n ‘

d i f f e r e n t

ways

in

the

e l e c t r i c c i r c u i t .

F o r

in

s t a n c e , a c c o r d i n g

t o

an embodiment o f my

i n

v e n t i o n , i t i s s o arranged a s t o

be

a b l e t o a b s o r b ,

3 5

when i t i s

s e t

i n v i b r a t i o n , a

c e r t a i n

p o r t i o n o f

the energy o f the

c i r c u i t i n which

i t

i s inserted,

In t h i s

w a y ,

‘ w h e n ,

t h e

v i b r a t o r y c o n d i t i o n s o f

the

c r y s t a l

are

modi?ed, as a consequence

o f

a

v a r i a t i o n o f t h e

p r e s s u r e

t o

which t i s s u b j e c t e d ,

t h e

p o r t i o n o f

the e n e r g y

o f t h e ~

c i r c u i t t h a t i s

a b s o r b e d by t h e v i b r a t i o n o f t h e c r y s t a l v a r i e s ,

‘ a n d t h e r e f o r e the energy

a v a i l a b l e i n

the c i r c u i t

a l s o v a r i e s . I t

s u f f i c e s

t o

u t i l i z e the v a r i a t i o n s

o f

c u r r e n t t h a t

a r e

thus pro dui

d ,

through any s u i t

4 5 / a b l e m e t h o d s ,

s u c h , f o r i n s t a n c e , as

a r e

a l r e a d y

k n o w n

t o those

s k i l l e d

i n

the a r t f o r t h i s p u r p o s e ,

f o r measuring, o b s e r v i n g , o r

r e c o r d i n g t h e v a r i a

t i o n s o f p r e s s u r e ,

o r

again

f o r c o n t r o l l i n g c e r t a i n

apparatus t h a t

a r e t o

w o r k ‘ r e s p o n s i v e

t o

s a i d

' 5 0 variations of p ressure. ,

The

c r y s t a l

may a l s o ,

a c c o r d i n g v t o

a n o t h e r

embodiment

o f my n v e n t i o n , be mounted i n the

c i r c u i t i n such manner~ as tosustain or s t a b i l i z e

the current o s c i l l a t i o n s s o that the v a r i a t i o n s

o f

5 5

p r e s s u r e t o

which t h e

c r y s t a l i s

s u b j e c t e d

produce

dispose

a

i e z o - e l e c t r i c

c r y s t a l ,

or

equivalent de-

c a t i o n s arethen

u t i l i z e d

f o r m e a s u r i n g , o b s e r v

i n g ,

e t c . ,

t h e

v a r i a t i o n s

o f

p r e s s u r e .

I t w i l l

be noted t h a t

i n

both c a s e s the c r y s t a l

i s

u t i l i z e d in such manner as to

act

o n the cur

rent

in a c i r c u i t s o a s ‘ t o modify the character

i s t i c s

o f s a i d c u r r e n t . This method p e r m i t s , o n

t h e

one

hand

t o o b t a i n measurements that a r e

very a c c u r a t e ,

and

o n the other

hand to s e t i n

o p e r a t i o n

q u a n t i t i e s o f

e l e c t r i c i t y

t h a t

a r e r e l a

t i v e l y l a r g e s o

t h a t the

a c t i o n s

or measurements

t h a t a r e o b t a i n e d can be u t i li z e d e a s i l y f o r prac

t i c a l purpms. This

s d i f f e r e n t

from what t a k e s

p l a c e i n

e x i s t i n g p i e z o - e l e c t r i c

dynamometers i n

which

t h e p r e s s u r e s a r e measured by t h e e l e c t r i c

‘ c h a r g e

p r o d u c e d

b y

t h e

p i e z o - e l e c t r i c c ry s t a l a s

a

r e s u l t '

o f

i t s

b e i n g compressed

o r

expanded.

This

charge

s

always v e r y s m a l l

and

i s

very

d i f

? c u l t

t o

measure.

Furthermore,

when

i t i s

de

s i r e d t o measure a

continuous

presure,

the

charge produced

a s

a r e s u l t

o f s a i d p r e s s u r e

does

n o t r e m a i n , due t o

t h e

i m p o s s i b i l i t y o f

o b t a i n i n g

a

p e r f e c t i n s u l a t i o n , which

makes

measurements

still

more

ifficult. a - '

Another

o b j e c t o f

my

i n v e n t i o n

i s toprovide

a

microphone working

o n the p r i n c i p l e

above

e x p l a i n e d

and i n

which t h e p r e s s u r e s t h a t a c t

on t h e p i e z o - e l e c t r i c

c r y s t a l

a r e produced by

the

soundwaves.

.

1 0

20

25

S t i l l a n o t h e r o b j e c t

o f

my

n v e n t i o n

i s t o p r o - ~

v i d e a d e v i c e f o r reproducing

sounds

recorded on

a

ph on og ra ph ic disc

o r any other

sound

record,

this

device

forming

a

pick-up

in

which

the

pres

sures that are intended t o operate e sound

r e p r o d u c i n g

s y s t e m

a r e p r o d u c e d by

t h e

d i s p l a c e

ment

o f t h e n e e d l e o f t h e pick-up i n

the

g r o o v e

of

a phonographic

record.

‘

This

d e v i c e

e s s e n t i a l l y comprises

a p i e z o - e l e c

t r i c

c r y s t a l ( p r e f e r a b l y

q u a r t z )

adapted t o

v i

brate in an

e l e c t r i c

c i r c u i t

tuned

t o

resonance

with

t h e

n a t u r a l f r e q u e n c y o f

t h e c r y s t a l .

The

30

40

p i e z o - e l e c t r i c c r y s t a l

i s

placed and

arranged

i n

‘ s u c h manner

that

i t s

s u r f a c e i s subjected

t o

v a r i a t i o n s ‘ o f

p r e s s u r e when

the

n e e d l e

o f the

pick-up

runs i n t h e groove o f the phonographic

r e c o r d . These v a r i a t i o n s o f

p r e s s u r e

have f o r

t h e i r e f f e c t t o damp

t h e

v i b r a t i o n s

o f

t h e

c r y s t a l

and

t h e r e f o r e t o

produce c e r t a i n e i e c i r i c e f f e c t s .

The crystal

that

i s usedv w i l l preferably be of a

thickness that varies

over

i t s

surface

so as t o

resonate

f o r a frequency

band

corresponding a t

l e a s t to t w i c e the frequency band t o be

r e p r o

duced ‘ .

The

sound

r e p r o d u c i n g d e v i c e a c c o r d i n g

t o my

i n v e n t i o n

can

be

u t i l i z e d

not only with r e c o r d s

p r o v i d e d

with

g r o o v e s but a l s o with any o t h e r

4 . 5

55


6/9L

2

2,096,106

s y s t e m f o r o p e r a t i n g t h e p i c k - u p

e i t h e r

m e c h a n i

v c a l l y

o r

m a g n e t i c a l l y o r

i n ? a n y

o t h e r s u i t a b l e

way

, _

My n v e n t i o n i s

a l s o - i n t e n d e d

t o b e a p p l i e d t o

aerodynamic balances

o r

dynamometers, t o , ac

c e l e r o m e t e r s

e s p e c i a l l y

‘ a d a p t e d

t o b e u s e d

i n

v c o n n e c t i o n

with

a i r p l a n e s ,

t o apparatus

f o r

r e

ceiving

electro-sonorous

waves, e t c . . .

Another o b j e c t o f my

n v e n t i o n

i s t o

p r o v i d e

a

p i e z o - e l e c t r i c c r y s t a l t h a t i s c a p a b l e

o f

v i b r a t i n g

at frequencies ranging‘ between r e l a t i v e l y wide

l i m i t s .

I t

i s well-known that an

ordinary

piezo

15

e l e c t r i c

c r y s t a l i s

c a p a b l e

of

v i b r a t i n g o n l y

at

f r e q u e n c i e s

e q u a l ,

o r

n e a r l y e q u a l , t o i t s n a t u r a l

f r e q u e n c y o f v i br a t i o n . T h i s

i s

o f

c o u r s e

r a t h e r

a hindrance f o r t h e working o f t h e method and

apparatus above r e f e r r e d t o .

-

s t i l l greater di?iculty in the case of a piezo-elec

20

25

t r i c

c r y s t a l

used f o r recording sounds o n a

?lm

through t h e

s o - c a l l e d

“ v a r i a b l e

d e n s i t y "

meth

o d . In t h i s c a s e ,

the c r y s t a l

through

which

‘ p a s s e s

t h e

l i g h t

beam

t h a t

i s

t o s e n s i t i z e t h e

?lm

i s i n s e r t e d i n a h i g h f r e q u e n c y a l t e r n a t i n g

? e l d

adapted

t o

cause s a i d c r y s t a l

t o

r e s o n a t e .

a t

low frequency

i n

accor dance with the i n t e n

. s i t i e s

o f the sounds t o be recor ded

so that

the

30

( . 0 C r

40

r e s u l t i n g v a r i a t i o n s i n

t h e a m p l i t u d e

o f v i b r a t i o n

o f t h e

c r y s t a l

may

modulate

a c c o r d i n g l y t h e i n

t e n s i t y o f t h e

l i g h t

beam t h a t p a s s e s

t h e r e

through.

I t

i s known

that i n t h i s

case

the

?xed

high

f r e q u e n c y i s

r e p l a c e d

by

a

f r e q u e n c y b a n d ,

due t o

s i d e f r e q u e n c ie s , s o t h a t ,

i n

order t o ob

t a i n a

good r e s u l t ,

t h e c r y s t a l s h o u l d

be

c a p a b l e

. o f v i b r a t i n g v f o r ‘ a ‘ f r e q u e n c y band, which i s n o t

t h e c a s e f o r an

ordinary


c r y s t a l .

In

o r d e r

t o

a v o i d

t h i s

drawback,

a c c o r d i n g

t o

my

i n v e n t i o n , t h e c r y s t a l i s c u t

i n

such manner

that i t comp rises zones or s e r i e s o f z o n e s , capable

o f being

s e t

in resonance v i b r a t i o n f o r

a l l

the

frequencies included

i n

the frequency band that

4 . 5

55

7 5

is

considered. _ v

For

i n s t a n c e ,

a c c o r d i n g t o

an

embodiment o f

my

i n v e n t i o n , t h e - \ p i e z o - e l e c t r i c c r y s t a l c o n s i s t s

o f

a prism having two o p p o s i t e

f a c e s i n c l i n e d

with r e s p e c t

t o

each o t h e r and t r a n s v e r s a l l y d i s

p o s e d ( s u b s t a n t i a l l y

a t r i g h t

a n g l e s ) t o ‘ t h e e l e c

t r i c

? e l d ,

t h e

d i r e c t i o n o f the

l i g h t r a y s b e i n g l o

cated i n

a

planesubstantially

a t r i g h t

a n g l e s

t o

s a i d two

f a c e s

between s a i d two f a c e s .

These and other objects of my nvention w i l l

b e

h e r e i n a f t e r

d i s c l o s e d

i n

t h e

f o l l o w i n g

d e t a i l e d

d e s c r i p t i o n

o f p r e f e r r e d embodiments o f my i n

v e n t i o n

with

r e f e r e n c e t o t h e accompanying

d r a w i n g s , g i v e n m e r e l y ’ b y ‘ w a y o f e x a m p l e , and

in

which: I i ’

F i g . 1 i s a diagrammatical

view

showing a d e

v i c e

according

t o my

n v e n t i o n i n which the c r y s

t a l

absorbs a portion o f the energy of an e l e c t r i c

circuit; _

F i g . ‘ 2

s h o w s a n o t h e r

embodiment i n

which

t h e ‘ c r y s t a l m a i n t a i n s

t h e

e l e c t r i c o s c i l l a t i o n s i n

’ a

c i r c u i t ;

F i g . 3

i s

a d i a g r a m m a t i c a l v i e w o r s t i l l a n

o t h e r

embodiment o f

t h e d e v i c e according t o my

invention; ‘

F i g .

4

i s a

f r o n t

view o f a

microphone

accord

ing to my invention}

/

F i g .

5 i s

a

view

o f ‘ t h e p i e z o - e l e c t r i c c r y s t a l

used

i n

said

microphone;

1 '

F i g .

6

i s a v e r t i c a l

s e c t i o n a l

view

o f a pick-up

according to my nvention;

F i g . ' 7

i s

a s i m i l a r view o f

another

embodiment

of a pick-up according

to my

invention;

F i g . 8 ' i s

a

p i e z o - e l e c t r i c c r y s t a l c u t i n s u c h

It

i s a

s our ce

of

The

i n t e n s i t y o f

t h e

h i g h

f r e q u e n c y ? e l d i s m o d u l a t e d

manner as t o f orm the needle o f

a

pick-up ac

cording

to

my nvention; .

F i g . 9

i s

a p e r s p e c t i v e view

o f

another

p i e z o

e l e c t r i c

c r y s t a l

adapted t o form

t h e

n e e d l e o f

a

pick-up; - _ r .

F i g .

1 0 i s a s e c t i o n a l view

o f

another embodi

ment o f a pick-up accor ding

t o my n v e n t i o n ;

F i g . 11

i s a

perspective‘view of a piezo-electric

‘ c r y s t a l a c c o r d i n g

t o

my i n v e n t i o n ;

F i g .

1 2 i s a p e r s p e c t i v e

v i e w o f a n o t h e r

embodi

ment

o f

t h e


c r y s t a l ;

F i g . 1 3 i s

a p e r s p e c t i v e

view o f s t i l l another

embodiment o f t h e p i e z o - e l e c t r i c

c r y s t a l

s i m i l a r

t o t h a t o f F i g . - 3 , b u t

w i t h

i t s o p t i c a l a x i s d i s

posed in

a

different

manner;

.

F i g .

1 4 i s

a curve

i l l u s t r a t i n g the

phenomenons

t h a t

occur

i n

the

c r y s t a l o f F i g s . 11, 1 2

and

1 3 . ‘

Referring t o

F i g .

1 ,

i t w i l l be

s e e n t h a t

the o s

c i l l a t o r y

c i r c u i t c o n s i s t s o f a r e a c t a n c e

c o i l

L 1

and

an a d j u s t a b l e

condenser

C 1 , t h e o s c i l l a t i o n s

i n s a i d

c i r c u i t b e i n g s e t up by a t h r e e - e l e c t r o d e

t u b e

_ A 1 .

The

c u r r e n t

i n

t h i s c i r c u i t

p r o d u c e s

i n

d u c t i v e l y

an

o s c i l l a t i n g

c u r r e n t i n the

second

c i r

1 5

2 0

c u i t adapted to be tuned

t o

resonance

therewith

‘

and c o n s i s t i n g o f a reactance c o i l

L2

and an

ad

j u s t a b l e condenser C 2 .

o f

a p i e ' z o - e l e c t r i c c r y s t a l Q ( p r e f e r a b l y

q u a r t z ) ,

p l a c e d between t w o armatures b and d , i s con

nected

t o

the t e r m i n a l s

o f

inductance c o i l L 2 .

Coil

L 2 ,

o r

at

least a

portion

thereof, i s

placed

'

i n the g r i d c i r c u i t o f detector tube A “ . When

condensers C 1 and C 1 2

a r e

a d j u s t e d insuch

man

ner that

the tw o above d e s c r i b e d c i r c u i t s a r e

tuned

t o resonance with

each other

so

that crys

t a l Q i b r a t e s , a c e r t a i n amount

o f the energy

i n

t h e c i r c u i t

o f

c o i l L 2 i s a b s o r b e d by

s a i d

v i b r a t i o n s .

A

c o n d e n s e r

c o n s i s t i n g

The

pressure

t o

be

measured

i s

applied/to

oppo-

s i t e

f a c e s

o f

s a i d c r y s t a l ,

and

w h e n ‘ s a i d p r e s s u r e

v a r i e s ,

t h e

amount

o f energy

absorbed by

t h e

c r y s t a l i s

v a r i e d and consequently t h e

mean

po

-

t e n t i a l

o f g r i d g and tube A2 i s

v a r i e d .

This pro

duces a

v a r i a t i o n o f the p l a t e c u r r e n t

o f

s a i d de

t e c t o r

tube

A2

w h i c h , may

be u t i l i z e d i n v a r i o u s

ways which

w i l l

be

h e r e i n a f t e r d e s c r i b e d

f o r

m e a s u r i n g ,

o b s e r v i n g ,

o r

r e c o r d i n g t h e

p r e s s u r e s

a c t i n g . o n c r y s t a l

Q , o r

f o r

o p e r a t i n g

c e r t a i n ap

40

paratus

in

accordance

with

variations of

s a i d

pressure. I .

In t h e embodiment o f F i g . 2 , a p i e z o - e l e c t r i c

, c r y s t a l

i s

inserted in

an

e l e c t r i c

c i r c u i t

so as

t o

s u s t a i n o r

s t a b i l i z e the o s c i l l a t i o n s

o f current in

s a i d

c i r c u i t .

, T h i s a r r a n g e m e n t

c o m p r i s e s

‘ a t h r e e - e l e c t r o d e

e l e c t r o n

t u b e A 3 , t o t h e p l a t e c i r c u i t

o f

which

there isconnected a

battery ‘ a n d

. a n

o s c i l l a t o r y

c i r c u i t

including

a reactance c o i l L3 and an

ad

j u s t a b l e condenser 0 3 .

. T h e g r i d c i r c u i t i n c l u d e s

a c o n d e n s e r c o n s i s t i n g o f a p i e z o - e l e c t r i c c r y s t a l

Q mounted betw een tw o armatures b and d . The

proper

n e g a t i v e

b i a s i s a p p l i e d t o the

g r i d

through

a

choke coil

K.

. _

The arrangement

d e s c r i b e d and

i l l u s t r a t e d

i n

' F i g . 2 i s a w e l l

kn o w n arrangement and

can be

r e p l a c e d

by any o t h e r s u i t a b l e a r r a n g e m e n t , t h e

f u n c t i o n o f .

condenser b ,

q and

d

b e i n g t o

s u s t a i n

h i g h

f r e q u e n c y o s c i l l a t i o n s and t h e c i r c u i t L 3 , C 3 .

hen

h e


Q

s s u b j e c t e d t o

. a

c e r t a i n p r e s s u r e ,

t h e

c u r r e n t i n

r e a c t a n c e c o i l

L3 v a r i e s .

These

v a r i a t i o n s

can

be u t i l i z e d e i t h e r

f o r

m e a s u r i n g , r e c o r d i n g ,

o r

o b s e r v i n g t h e p r e s ;

s u r e ,

o r f o r c o n t r o l l i n g t h e

working

o f any

de

sired apparatus.

.

I t

w i l l be

noted

t h a t ,

i n

both o f

the arrange

ments a b o v e d e s c r i b e d , c r y s t a l Q a s

n o n - p a r a l

l e l

o p p o s i t e

f a c e s , f o r

r e a s o n s t h a t w i l l

b e

h e r e i n

5 0

6 0

6 5

7 0

7 5


7/9

10

1 5

2 0 .

a f t e r e x p l a i n e d : However, i t

s h o u l d be

w e l l

un_

d e r s t o o d t h a t ‘ t h i s

i s n o t

a n e c e s s a r y

o f

,

mynvention. . Y

o n t h e

o t h e r - h a n d ,

t h e .

s u p p o r t

and

t h e arma

t u r e s o f _ t h e c r y s t a l may b e g i v e n ‘

any

s u i t a b l e

shape

and arrangement

w i t h o u t d e p a r t i n g - f r o m

the p r i n c i p l e

o f

my i n v e n t i o n .

The

armatures

may

f o r

i n s t a n c e

c o n s i s t o f m e t a l l i c ' p l a t e s ‘ o r

coatings

deposited

o n the surface o f the

c r y s t a l ,

which may,

f o r

i n s t a n c e - b e

s i l v e r e d . A l t e r n a t e

l y ,

t h e

c r y s t a l

might b e

r i g i d l y

c o n n e c t e d

t o

an

o t h e r

b o d y , f o r

i n s t a n c e a r e l a t i v e l y

t h i c k

m e t a l

p l a t e d i r e c t l y

s u b j e c t e d ' t o

t h e v a r i a t i o n s o f p r e s

sure '

The v a r i at i o n s o f t h e h i g h f r e q u e n c y c u r r e n t

that

are

obtained as ‘ a consequence

o f

the varia

tions o f pressure

o n

one o r more

faces

of

the

c r y s t a l maybe u t i l i z e d e i t h e r d i r e c t l y o r a f t e r d e

t e c t i o n . T h u s , f o r

i n s t a n c e ,

h i g h f r e q u e n c y c u r ‘

r e n t s

t h e

a m p l i t u d e s o f which

vary

a t

low

f r e

quency, as i t i s the

case

in

a

microphone

or a

p i c k - u p ,

can

b e u t i l i z e d d i r e c t l y , w i t h o u t

d e t e c

t i o n .

I n

t h i s c a s e

s a i d h i g h f r e q u e n c y

c u r r e n t s

may be

d i r e c t l y u t i l i z e d

f o r e m i t t i n g

e l e c t r o - m a g

n e t

w a v e s . Such

a

d e v i c e

would

be

c o n s t i t u t e d

by

t h e

arrangement

o f

F i g .

2

i n

which an

anten

na would

b e

coupled-with

c o i l L 3 . ‘

30

40

t u b e .

On

the other hand, highfrequency currents

t h e

a m p l i t u d e s o f w h i c h - v a r y a t l o w f r e q u e n c y ,

as

i n a microphone

or

a

pick-up,

may

be caused

‘ t o a c t

on a

d e t e c t o r , the c u r r e n t t h a t i s

u t i l i z e d

b e i n g thenthe d e t e c t e d c u r r e n t .

I t s h o u l d

a l s o b e

w e l l u n d e r s t o o d t h a t

t h e d e

t e c t o r i s n o t

n e c e s s a r i l y

a

t h r e e - e l e c t r o d e

e l e c t r o n

F o r i n s t a n c e , i n

t h e

c i r c u i t s a b o v e d e

s c r i b e d ,

t h e t h r e e

e l e c t r o d e

t u b e might b e r e

. placed b y a diode tube or any

other equivalent

d e v i c e .

‘ B y way o f

e x a m p l e , a P h i l i p s ‘

" b i n o d e ”

tube

might ‘ b e

substituted

f o r the three e l e c t r o d e

’

tuba. - _ .

In

a -

g e n e r a l

way,

any

c i r c u i t , , o r

combination

> o f

c i r c u i t s ,

t h a t

i s c a p a b l e o f s e t t i n g

t h e p i e z o

e l e c t r i c c r y s t a l i n v i b r a t i o n s o t h a t v a r i a t i o n s

in the

characteristics

o f , an electric current are

45 produced i n consequence o f v a r i a t i o n s o f p r e s

~

sure exerted

o n the crystal

can be

u t i l i z e d accord

v 5 0 '

6 0

i n g

tomy n v e n t i o n , t h e e x a m p l e s a b o v e d e s c r i b e d

h a v i n g b e e n g i v e n m e r e l y b y - way

o f

e x a m p l e .

B e s i d e s ,

t h e

r e s o n a t i n g

e l e m e n t s u b j e c t e d t o

the

a c t i o n o f

a p r e s s u r e

t o be measured,

o b s e r v e d ,

o r ' r e c o r d e d o r

intended

t o c o n t r o l t h e working

o f a g i v e n

a p p a r a t u s .

i s not n e c e s s a r i l y a p i e z o

e l e c t r i c c r y s t a l .

I t

may, ‘ f o r i n s t a n c e , according

t o

my i n v e n t i o n , c o n s i s t

o f a magneto-striction

d e v i c e , a s

shown

i n

F i g . 3 . The

c i r c u i t

shown

i n

t h i s ‘ f i g u r e

i s s i m i l a r t o t h a t o f

F i g .

1 . H o w e v e r ,

L " . A magnetic

c o r e

t i s

p l a c e d i n t h e

magnetic

? e l d

and t h e p r e s s u r e

t o

b e

m e a s u r e d ,

o b s e r v e d ,

o r recorded o r intended

t o

c o n t r o l

t h e working

o f

a given apparatus i s applied

t o s a i d

core .

I t

w i l l

be

noted

t h a t i n

F i g .

3 , I have replaced

the three e l e c t r o d e

tube AI o f the

embodiment

o f

65

7 0

7 5

F i g .

1

by

a

P h i l i p s “ b i n o d e ”

t u b e

o f

a _ kn o w n

t y p e ,

i n

o r d e r

t o

show

t h a t

t h e examples g i v e n

a r e

sub

j e c t

t o many m o d i ? c a t i o n s

w i t h o u t

d e p a r t i n g

f r om the

principle

of

my

n v e n t i o n . /

I n F i g s .

4

and

5 , I have

shown a

microphone

according

to

my

nvention.

I t comprises a rigid

_ r i n g 1 ' , made for

instanceof

m e t a l , t o which a

~ p i e z o s - e l e c t r i c

c r y s t a l

Q

( q u a r t z p r e f e r a b l y )

i s

e l a s t i c a l l y connected i n a c e n t r a l

p o s i t i o n , f o r i n

s t a n c e v b y means

of

f o u r s p r i n g s s . The o p p o s i t e ;

f a c e s o f

c r y s t a l Q h a t a r e

l o c a t e d

i n

p l a n e s s u b

8 , 0 9 6 , 1 0 6

3

s t a n t i a l l y

p a r a l l e l

t o

t h e

p l a n e o f r i n g

1 '

a r e p r o

v i d e d w i t h

m e t a l l i c

a r m a t u r e s ,

f o r

i n s t a n c e t h i n

c o a t i n g s o f

s i l v e r

o r ‘

any

other s u i t a b l e m e t a l .

T w o

c l i p s

u ‘ i t 2 each c o m p r i s i n g a

m e t a l l i c

branch

( l 1

I I r e s p e c t i v e l y ) and

an i n s u l a t i n g branch ( 9 ,

i ‘

. r e s p e c t i v e l y ) are f i x e d t o said

c r y s t a l

Q n such

manner that

m e t a l l i c branch 1 1

i s

i n contact

with

one o f

the

s i l v e r e d f a c e s o f

t h e

c r y s t a l w h i l e

the

other one

P

s i n contact with

the other

s i l v e r e d

face

of the

c r y s t a l . These br anches

1 1 P

are

con

n e c t e d

t h r o u g h

w i r e s

e

1 '

r e s p e c t i v e l y t o

t e r m i n a l s

0 h

which

are connected to

a

s u i t a b l e

c i r c u i t such

a s the one shown i n e i t h e r o f F i g s . 1 and 2 in the

same

manner as

armatures

b and d i n said ? g

ures.

‘

has J u s t been d e s c r i b e d

i s

p a r t i c u l a r l y advan

t a g e o u s i n

t h a t

i t i s

symmetrical

and both o f i t s

faces are

operative.

'

I

w i l l

now d e s c r i b e examples o f pick-ups ac

c o r d i n g t o my n v e n t i o n .

A d v e r t i n g f i r s t

t o

F i g . 6 , a p i e z o - e l e c t r i c

c r y s t a l ’

Q s p l a c e d between

two

armatures 2

and {Leon

nected by means o f lead

wires

4 and 5 with a s u i t

a b l e e l e c t r i c c i r c u i t f o r

i n s t a n c e

o f

one

o f

t h e

I t s h o u l d b e n o t e d t h a t t h e ‘ m i c r o p h o n e t h a t

5

10.

1 5

25.

types

above

d e s c r i b e d . ‘

The

whole

i s

placed

i n

a

support 6 . The two a r m a t u r e s ‘ 2 and 3 a r e ap

p l i e d a g a i n s t t h e s u r f a c e

o f

t h e

c r y s t a l by

s p r i n g s

‘ I , 8 , 9 and

I 0

p l a c e d

i n

h o u s i n g s p r o v i d e d

i n sup

p o r t 6 ,

i n

such

manner

asto e l a s t i c a l l y a p p l y t h e

a r m a t u r e s a g a i n s t

t h e f a c e s

o f t h e

c r y s t a l .

Support 6

i s

c l o s e d a t i t s l o w e r part by an i n

s u l a t i n g

l i d

I I

?xed

f o r

i n s t a n c e

by ~means

o f

screws

I 2

and

I 3 .

This

l i d - i s

provided with

an

a p e r t u r e

I t

through

which p a s s e s armature

3 ,

t h e l o w e r p a r t o f

which

p r o j e c t s

from

t h e l i d and

a c t s a s

a

support I 5 _ f o r ‘ t h e n e e d l e I 8 , which

i s

clamped i n t h e

s u p p o r t i n

t h e u s u a l way

b y

means

o f

a screw

I ' I .

Whenneedle

I 6 runs

i n the groove o f the

r e c o r d ,

t h e

armature

3

which

i s

e l a s t i c a l l y

ap

p l i e d

a g a i n s t t h e

f a c e

o f c r y s t a l I , e x e r t s

on

the

l a t t e r a

p r e s s u r e that v a r i e s

according t o the

shape

o f t h e g r o o v e ,

and

t h e amplitude o f t h e

v i b r a t i o n s ofthe

c r y s t a l v a r i e s

a c c o r d i n g l y ,

t h u s

p r o d u c i n g

e l e c t r i c

v a r i a t i o n s i n

t h e c i r c u i t t o

w h i c h c r y s t a l Q ' i s c o n n e c t e d t h r o u g h

w i r e s

4

and .

30

40

45

t h e example

o f

F i g .

7 , s u p p o r t

6 ,

i s

made i n ‘ ?

the same manner a s i n the preceding embodi

m e n t . H o w e v e r ,

i n

t h i s

c a s e ,

i n d e p e n d e n t

n e e d l e

I

i s

d i s p e n s e d w i t h and

s

r e p l a c e d

by

t h e

c r y s t a l

i t s e l f the lower part o f which s c u t i n

such

man

.

ner as

to f o r m a . point

I 9

adapted t o r un in

the

g r o o v e s

o f

t h e phonographic r e c o r d . C r y s t a l Q

I , I

, i s

placed,

a s ’

in

the pr eceding

example,

between

the

piezo-electric crystal

i s

done

away

with

and

a

. c o l l L 4 i s . c o n n e c t e d

i n

s e r i e s

with

_ r e a c t a n c e

c o i l

two armatures

2

and

3 ,

which a r e

e l a s t i c a l l y ap

p l i e d a g a i n s t i t s f a c e s

by s p r i n g s ‘ I ,

8 , 9 , I 0 . Sup

port I

i s closed

by

l i d

i i

provided

with

an

open- Y

ing through

which

the point I 9

of crys

talQ; ' . ‘

7

. V

In

t h i s

embodiment

of my

n v e n t i o n ,

when t h e

e x t r e m i t y - l l o f t h e c r y s t a l runs i n

t h e

g r o o v e ,

t h e

p r e s s u r e t h a t

i s

e x e r t e d on

the

c r y s t a l v a r i e s

and

produces

theldesired

e f f e c t s .

I n t h e example o f F i g . 8 , t h e c r y s t a l ,

i n s t e a d

o f

b e i n g p l a c e d i n a d i r e c t i o n ‘ s u b s t a n t i a l l y a t r i g h t

a n g l e s t o t h e s u r f a c e o f t h e r e c o r d

t h a t

i s

p r o - Y

v i d e d with g r o o v e s , i s d i s p o s e d i n a d i r e c t i o n sub

s t a n t i a l l y p a r a l l e l t o . s a i d s u r f a c e .

I t

should be w e l l

understood

that with

such an

arrangement

o f ,

the

c r y s t a l ,

t h e n e e d l e

may

be

e i t h e r

independent

a s

shown i n

F i g .

6 and

a s

i t

w i l l

be

h e r e i n a f t e r e x p l a i n e d , or

i t

may

be

c u t

i n the mass

o f

c r y s t a l ‘ Q ,

thus

c o n s i s t i n g

o f

a

7 0

7 5


8/9

' 1 0

1 5

20

25

30

.35

6 0

4

p o i n t ‘

2 8

adapted

t o

run i n t h e g r o o v e s o f t h e

r e c

ord. \

I n t h e example o f F i g .

8 ,

t h e f a c e s o f

t h e

c r y s t a l

are coated with metal s o

a s to

fo r m armatures

which

a r e connected

through w i r e s

2 9 and

3 0 t o

the

c i r c u i t i n

w h i c h - i s i n s e r t e d

t h e

c r y s t a l .

In

t h e

example o f F i g .

1 0 , t h e

c r y s t a l i s d i s

posed

p a r a l l e l l y

t o t h e

s u r f a c e o f

t h e r e c o r d p r o

v i d e d w i t h g r o o v e s . H o w e v e r , i n

t h i s

e x a m p l e ,

t h e a r m a t u r e s , i n s t e a d o f

v c o n s i s t i n g o f

m e t a l l i c

c o a t i n g s

‘ d e p o s i t e d

o n

t h e

f a c e s

o f

the

c r y s t a l ,

c o n s i s t o f metallic p lates 32

and

33 connected t o .

t h e

c i r c u i t

through w i r e s

3 %

and 3 5 .

The lower

p l a t e 3 3 forms

a support 3 6 f o r

an

independent

n e e d l e 3 1 ?xed i n s a i d s u p p o r t ,

i n

t h e u s u a l way,

b y means

of

a screw 3 8 .

F i g .

9

i s

a p e r s p e c t i v e view o f a c r y s t a l s i m i l a r

t o t h a t shown i n

F i g . 3

and a p o r t i o n

o f

which

forms t h e ‘ n e e d l e .

H o w e v e r , v

i n

t h i s

e x a m p l e ,

c r y s t a l

Q n s t e a d o f having i t s

f a c e s

c o a t e d

with

m e t a l ,

i s p l a c e d between

tw o armatures 3 9 and

4 0 connected

t o

t h e c i r c u i t

through w i r e s

t i

and

4 2 .

I t

should be w e l l understood t h a t t h e examples

t h a t have j u s t been

d e s c r i b e d

and i l l u s t r a t e d o n l y

.

show

some

possible

embodiments

of

the

device

a c c o r d i n g t o my

i n v e n t i o n . _

A r e a t number o f

o t h e r

embodiments may be

d e v i s e d a c c o r d i n g t o

my i n v e n t i o n ,

t h e c r y s t a l ,

t h e a r m a t u r e s , t h e mounting, t h e

s u p p o r t , e t c . ,

b e i n g

s u i t a b l y modi?ed w i t h o u t d e p a r t i n g from

the

spirit

o f my nvention. ‘

On

the o t h e r hand, the n e e d l e ,

which a s

above

s t a t e d , ‘may e i t h e r c o n s i s t o f

a

p o r t i o n o f the

c r y s t a l i t s e l f ,

or b e ‘ an

independent

p a r t ,

may.

a l s o i n

t h e

second c a s e ,

a c t

o n the c r y s t a l i n any

s u i t a b l e w a y . Thus, f o r i n s t a n c e , i n s t e a d o f be

ing c a r r i e d

by an

armature a p p l i e d a g a i n s t

t h e

f a c e

o f

t h e

c r y s t a l , a s i t ‘ h a s been

shown

and

i l l u s t r a t e d , i t may

a c t

o n the c r y s t a l i n d i r e c t l y

through

any

s u i t a b l e

t r a n s m i s s i o n .

F i n a l l y ,

I may u t i l i z e t h e v a r i a t i o n s

o f ‘

t h e ’

p r e s s u r e ‘ a p p l i e d t o t h e v i b r a t i n g c r y s t a l n o t f o r

m o d i f y i n g t h e

e l e c t r i c c i r c u i t

t h a t p r o d u c e s s a i d

v i b r a t i o n b u t d i r e c t l y , in view

o f

t h e

f a c t

t h a t

t h e r e e x i s t s

a s u r f a c e

( t h a t o f the c r y s t a l )

v i b r a t

i n g

a t high

f r e q u e n c y w i t h ' a m o d u l a t i o n

o f low

f r e q u e n c y . F o r ‘ i n s t a n c e , v s a i d s u r f a c e may be

m e c h a n i c a l l y

c o n n e c t e d t o

t h e

membrane o f any

o r d i n a r y microphone.

In

t h i s c a s e ,

t h e micro

phone c u r r e n t may e

o f high

f r e q u e n c y

modu-.

lated a t

low frequency.

.In

some

cases

due

t o

t h e i n e r t i a o f t h e

membrane,

o n l y t h e low f r e

q u e n c y

c u r r e n t

would s u b s i s t f o r p r a c t i c a l

pur

poses . '

T h e ‘ membrane i n q u e s t i o n might c o n s i s t o f

one

o f t h e f a c e s o f

the c r y s t a l i t s e l f .

,An

exam

p l e

o f an embodiment o f t h i s s i d e o f

our inven

tion w ould

be

the

following:

,

One

o f

the

f a c e s o f the c r y s t a l w i l l be con

nected t o

a

plate

o f

carbon or might be covered

i t s e l f with a l a y e r

o f

g r a p h i t e , and placed in

con-

t a c t with p a r t i c l e s o f

c a r b o n . I

would thus con

s t i t u t e a microphone o f the w e l l

k n o w n

carbon

t y p e working on

the

p r i n c i p l e o f my i n v e n t i o n .

,

One f the faces of the

c r y s t a l ‘ may

l s o c o n s t i

t u t e one_of the armatures o f an e l e c t r o - s t a t i c

o .

7 5

microphone.

,

The support o f the c r y s t a l

may

be g i v e n ; any

s u i t a b l e

s h a p e .

I t may f o r i n s t a n c e , c o n t a i n t h e

tuning

c i r c u i t o f

t h e c r y s t a l .

In t h i s

c a s e , t h i s

s u p p o r t

may

be

c o m p l e t e l y

c l o s e d ,

and

t h e

o u t e r

c o n n e c t i n g wires may

b e

c o m p l e t e l y d i s p e n s e d

j

A h i r d

i n t e r e s t i n g

a p p l i c a t i o n

o f my n v e n t i o n

2 , 0 9 6 , 1 0 6

c o n s i s t s

i n

a e r o d y n a m i c

b a l a n c e s

o r dynamome

t o r s

i n which

t h e element t h a t i s s u b j e c t e d t o t h e

p r e s s u r e o r t o the v a r i a t i o n s o f p r e s s u r e , i s ' a


working on

t h e

p r i n c i p l e v

above described.

I

Another


o f

my i n v e n t i o n

c o n s i s t s

i n

an

a c c e l e r o m e t e r

a p p l i c a b l e

more e s p e c i a l l y to”

> airplanes and i n which the organ responsive to

a c c e l e r a t i o n s

i n c l u d e s a


c r y s t a l

wor king on t h e

p r i n c i p l e

above

d e s c r i b e d .

This

l a t t e r

a p p a r a t u s

would

p r e f e r a b l y

b e "

combined

with

a

d e v i c e

f o r r e c o r d i n g t h e

maximums - o r

minimums

A n o t h e r


o f

my i n v e n t i o n i s t o

barometers.

_

The method a c c o r d i n g t o my

n v e n t i o n

might

a l s o

b e a p p l i e d t o

u l t r a - a u d i b l e

wave

r e c e i v i n g

a p p a r a t u s

i n

which t h e p i e z o - e l e c t r i c ‘ c r y s t a l a c t

ing

according

t o

the process above

described

a c t s

asa

e c e i v e r ,

or

both as

a r e c e i v e r

and

a trans

m i t t e r o f t h e u l t r a - a u d i b l e w a v e s . T h e s e ‘ appa

10

i s ’

2

ratus are m o r e particularly u t i l i z e d

in

water, ' f o r

instance for

soundin gsQ

In

any o f

t h e

above d e s c r i b e d embodiments o f

my i n v e n t i o n ,

t h e

p i e z o - e l e c t r i c c r y s t a l , w h i c h ‘

p r e f e r a b l y

c o n s i s t s

o f

a


q u a r t z ,

may

b e

o f v a r i o u s shapes

and

a r r a n g e m e n t s . Thus,

s a i d c r y s t a l may, c o n t r a r y t o

what i s shown

i n

t h e d r a w i n g s ,

h a v e

p a r a l l e l o p p o s i t e

f a c e s .

Fur

t h e r , I

have

found t h a t in v i e w o f t h e f a c t t h a t

a


‘ o f uniform t h i c k n e s s

i s

, . capable o f v i b r a t i n g only a t i t s natural f r e q u e n c y ,

i t

i s

p r e f e r a b l e t o

u s e

c r y s t a l s having a t h i c k n e s s

t h a t v a r i e s along t h e i r s u r f a c e s o t h a t t h e r e

i s

always a t h i c k n e s s o f

t h e

c r y s t a l t h a t c o r r e s p o n d s

t o any

e s i r e d

f r e q u e n c y w i t h i n a i c e r t a i n band o f

f r e q u e n c i e s . In t h i s way,

‘ t h e v i b r a t i o n s o f a

c r y s t a l can

be much

more

e a s i l y

modulated a s

a l r e a d y e x p l a i n e d

by me with r e f e r e n c e t o

o t h e r

a p p l i c a t i o n s

o f p i e z o - e l e c t r i c '

c r y s t a l s i n my

F r e n c h ‘ P a t e n t s

N o .

6 4 4 , 2 4 0 ,

6 9 6 , 8 1 7 , . - 7 1 1 , 6 6 l ,

‘ 7 2 6 , 8 5 0 . . I may l s o u t i l i z e a c r y s t a l

c u t i n

t h e

u s u a l

way

f o r r a d i o - e l e c t r i c a p p l i c a t i o n s .

On

t h e

o t h e r hand, the

p r e s s u r e

may be e x

‘ erted o n d i f f e r e n t

faces

of the c r y s t a l . ‘ I may or

i n s t a n c e , c a u s e the q u a r t z t o v i b r a t e i n

a

d i r e c t i o n

a t r i g h t

a n g l e s t o t h e e l e c t r i c and o p t i c a l

a x e s

and exert t he pressure o n

a

face at r i g h t angles

to said

direction.

' ' , . _

The

v a r i a t i o n

o f

t h e

t h i c k n e s s a l o n g t h e w h o l e

s u r f a c e

v o f

the c r y s t a l may

d i f f e r

according a s

the c a s e may b e . Thus,

i n

t h e

c a s e f o r i n s t a n c e

o f p r e s s u r e s t h a t

vary

very

r a p i d l y , I

may u t t h e

c r y s t a l

i n

such

manner

that t h e frequency band

w i t h i n which t h e

c r y s t a l can r e s o n a t e , ‘may be

e q u a l a t l e a s t

t o

t w i c e t h e band o f f r e q u e n c i e s

t o

2

3

3

4

be

observed,

measured

o r v

u t i l i z e d

for

c o n t r o l l i n g

c e r t a i n a p p a r a t u s . On

he

o t h e r hand, t h e

t h i c k

ness may be distributed in

‘ a

particular

way

in .

some

s p e c i a l c a s e s . Thus, i n

the c a s e

f o r i n s t a n c e

o f

modulated

p r e s s u r e s ,

i f i t

i s

d e s i r e d t o f a v o u r i z e .

high f r e q u e n c i e s o f

modulation, i t ma be ar

ranged that

t h e ' p a r t s o f

a

h i c k n e s s

that i s most

. d i ? ' e r e n t

from

t h e t h i c k n e s s ‘

c o r r e s p o n d i n g t o

t h e

frequency o f

v i b r a t i o n

i n the absence o f a modu

l a t i o n , may be

the greater as

the

d i f f e r e n c e be- "

tween t h e g i v e n t h i c k n e s s and t h a t corresponding

t o s a i d

‘ f r e q u e n c y i n

the absence o f

a modulation,

isgreater _ ‘ ,

In F i g s . 1 1 t o 1 4 , I have shown some examples

o f

p i e z o - e l e c t r i c c r y s t a l s i q u a r t z ) adapted t o v i

b r a t e

f o r

a w h o l e

band

o f f r e q u e n c i e s .

These c r y s t a l s s h a l l consist for i n s t a n c e : ( F i g .

l l )

o f a p l a t e o f quartz cut

i n thershape o f a

p r i s m h a v i n g a t r a p e z o i d a l b a s e , e i t h e r r e c t i l in e a r

6

6

7

0

5

0

0

5

0


9/9

9 096 106; ’

e r c u r v i l i n e a r , t h e t h i c k n e s s e s u a n d 2

( t h a t

i s

t o

s a y

t h e

l e n g t h s

o f

the

b a s e s

o f t h e

t r a p e z o i d t h a t

forms one o f t h e

b a s e s o f t h e

p r i s m ) d i f f e r i n g

_ from

each

other

by

a

value

that

depends

on the

1 0

2 0

t w o ‘maximum

and

minimum f r e q u e n c i e s

f o r

which

t h e c r y s t a l must b e c a p a b l e o f r e s o n a t i n g .

As already

explained,

the

provision

of a

crystal

adapted t o v i b r a t e

f o r a

wholeband

o f

f r e q u e n c i e s

i s p a r t i c u l a r l y

n e c e s s a r y when t h e

c r y s t a l s e r v e s

t o

modulate a

l i g h t

beam

r e s p o n s i v e

t o v a r i at i o n s

of the

?eld

i n

which

i t

v i b r a t e s .

In

t h i s c a s e ,

i t

, i s

important t h a t

t h e

l i g h t beam

should be p a r a l l e l

t o arrow F . The d i r e c t i o n o f t h e

? e l d

i s

shown

by

arrow

G.

In

a t h i n

p i e z o - e l e c t r i c p l a t e having

i t s

f a c e s

s l i g h t l y

i n c l i n e d w i t h r e s p e c t

t o

each

o t h e r

and

v i b r a t i n g i n t h e d i r e c t i o n o f i t s t h i c k n e s s , t h a t i s

t o say i n the d i r e c t i o n o f

edges 1 . and v

i n

a

c r y s t a l

a s

shown

i n

F i g .

1 1 theresometimes

e x i s t s a

c e r

t a i n z o n e

o f l o c a l i z e d v i b r a t i o n s r e s u l t i ng

from

the pro pagation o f waves i n the

d i r e c t i o n

u and v .

In

the application

of the

crystals

according

to

t h e

p r e s e n t i n v e n t i o n , t h i s

f e a t u r e might

have

a

d e t r i m e n t a l

e f f e c t i n some c a s e s . I t i s

p o s s i b l e

t o

a v o i d

t h i s d r a w b a c k ~ by making

u s e a s

shown

i n

F i g .

1 2 ,

i n s t e a d

o f

a

s i n g l e

p l a t e

o f

a

s e r i e s

o f

i d e n t i c a l

p l a t e s d i s p o s e d

s i d e b y s i d e , and c u t

i n

such

manner

as

to

resonate

for

the

same band

40

45

55

p r i s e s an important

r e c t i l i n e a r

o f f r e q u e n c i e s a s t h e s i n g l e

p l a t e o f

F i g . l . The

width w

f

each p l a t e , w i l l be s u f l l c i e n t i y s m a l l i n

order

t h a t t h e

propagation o f waves i n the d i r e c

t i o n

u-v

may

have

no detrimental e f f e c t . The

o p t i c a l

a x i s w i l l b e c h o s e n , f o r in s t a n c e , p a r a l l e l

to the direction

c-c.

~

I t i s

a l s o p o s s i b l e

t o

u t i l i z e a s i n g l e

p r i s m , a s

shown

i n F i g ,

1 3 ,

by s o d i s p o s i n g i t t h a t

t h e

d i r e c

t i o n

o f t h e l i g h t ‘beam s

p a r a l l e l

with the o p t i c a l

axis

o f

the

crystal.

The curve o f F i g . 1 4 shows the q u a n t i t y o f l i g h t

t h a t i s r e s t o r e d a t

a

f u n c t i o n o f

the amplitude

o f

t h e ? e l d

through

t h e

q u a r t z .

This

c u r v e

c om

part.

The mean workingzone

w i l l

be c h o s e n , a c c o r d

‘ i n g t o

my n v e n t i o n ,

i n t h e

c e n t r a l

p o r t i o n o f t h i s

s t r a i g h t p a r t o f t h e c u r v e .

On h e o t h e r h a n d , p h o t o g r a p h i c e m u l s i o n s a l s o

p o s s e s s

a

' s e n s i t i v e n e s s

t h a t v a r i e s

l i n e a r l y a s

a

f u n c t i o n

o f

t h e

i l l u m i n a t i o n between two l i m i t s

depending on t h e n a t u r e

o f

t h e s e e m u ls i o n s . The

m o d i ? c a t i o n

o f

t h e l i g h t

i n t e n s i t y

e m i t t e d

b y t h e

s o u r c e o r t h e a b s o r p t i o n o f a c e r t a i n amount o f

l i g h t

e n e r g y

by

s u i t a b l e s c r e e n s , w i l l make

t p o s

s i b l e

t o w o r k

in the most

f a v o u r a b l e

z o n e . ,

Through s u i t a b l e

o p t i c a l

means, the

p a r a l l e l

beam

i s s u i n g

from

t h e

a n a l y z e r i s

c o n c e n t r a t e d

i n such manner a s t o obtain a

l i n e , that

i s

the

?ner -

as t i s d e s i r e d t o l o s e

none

o f ' t h e

advantages o f

t h e

method a c c o r d i n g t o

t h e

i n v e n t i o n

f o r r e c o r d - *

i n g v e r y

h i g h f r e q u e n c i e s .

o n t h e o t h e r

h a n d ,

b e i n g g i v e n t h e ‘ g r e a t

u l t r a - v i o l e t

zone o f t h e

er

in

the

w h o l e

e l e c t r o

p t i c a l d e v i c e

( m o d u l a t o r , c o m

p e n s a t o r , p o l a r i z e r and a n a l y z e r ) i t i s i n t e r e s t

i n g t o make t h e remainder o f t h e o p t i c a l system

o f a

m a t e r i a l t h a t

i s

v e r y much

t r a n s p a r e n t t o

t h e s e

rays

( q u a r t z , ? u o r i n e ,

e t c . )

While

I

have

d e s c r i b e d what I deem

t o b e

p r a c t i c a l

and e i l i c i e n t

embodiments

o f

my i n

v e n t i o n , i t

s h o u l d

b e w e l l understood

t h a t

I do

n o t w i s h t o b e

l i mi t e d t h e r e t o a s t h e r e might

b e c h a n g e s made i n t h e a r r a n g e m e n t ,

d i s p o s i

t i o n

and

f o r m

o f

t h e p a r t s

w i t h o u t

d e p a r t i n g

from t h e p r i n c i p l e

o f my

i n v e n t i o n

a s compre

hended

w i t h i n t h e s c o p e o f the appended

c l a i m s .

What

I c l a i m i s :

1 . A d e v i c e f o r , t r a n s f o r m i n g p r e s s u r e v a r i a

t i o n s i n t o e l e c t r i c v a r i a t i o n s ,

which c o m p r i s e s a

magnetic

c o r e , a h i g h

f r e q u e n c y

e l e c t r i c

c i r c u i t

f o r

producing a magnetic ?eld adapted t o

a c t

on

s a i d c o r e

s o t h a t

' s a i d c o r e

i s caused

t o

undergo

h i g h f r e q u e n c y v i b r a t o r y c h a n g e s o f d i m e n s i o n

through ‘ a m a g n e t o s t r i c t i o n a c t i o n , and means

f o r

a p p l y i n g v a r i a t i o n s ofpressure t o s a i d

c o r e .

' s o

a s

t o

a c t o n the amplitude

o f

the v i b r a t i o n

t h e r e o f whereby e l e c t r i c v a r i at i o n s a r e

produced

i n s a i d

e l e c t r i c c i r c ui t .

2 .

A

p i c k - u p

f o r

r e p r o d u c i n g

sounds

from

a

phonographlc r e c o r d

which c o m p r i s e s

i n com

v b i n a t i o n ,

a p i e z o - e l e c t r i c

c r y s t a l ,

two

armatures

l o c a t e d on e i t h e r

s i d e ofsaid c r y s t a l , means f o r

a p p l y i n g

s a i d

armatures a g a i n s t

s a i d

c r y s t a l , an

e l e c t r i c c i r c u i t f o r g e n e r a t i n g

h i g h

f r e q u e n c y

e l e c t r i c c u r r e n t c o u p l e d w i t h

s a i d

c r y s t a l and

tuned t o resonance therewith

s o that t h e

c r y s t a l

i s c a u s e d t o v i b r a t e a t high

f r e q u e n c y , t h e end

o f

s a i d c r y s t a l

b e i n g

c u t i n

t h e shape

o f a

n e e d l e

s o

a s t o c o o p e r a t e

with

s a i d r e c o r d

f o r transmit

t i n g t h e r e t o

v a r i a t i o n s

o f p r e s s u r e from s a i d

record _

3 . An e l e c t r i c c i r c u i t f o r g e n e r a t i n g

high

f r e

quency

e l e c t r i c

c u r r e n t , c o m p r i s i n g ' a p l e z o - e l e c

t r i c c r y s t a l , s a i d c r y s t a l b e i n g a d a p t e d t o

c o n t r o l

the frequency

o f s a i d

c u r r e n t ,

the dimension o f

t h e

c r y s t a l

i n t h e d i r e c t i o n i n which i t r e s o n a t e s ’

b e i n g non-uniform s o , a s t o make t h e

c r y s t a l

resonant

f o r

a

band o f f r e q u e n c i e s

and t h e

f r e q u e n c y

o f

t h e c u r r e n t b e i n g i n c l u d e d

w i t h i n

t h e band

f o r which

t h e

c r y s t a l i s r e s o n a n t .

4 . A d e v i c e f o r t r a n s f o r m i n g

p r e s s u r e

v a r i a

tions into-electric variations which c omp rises a

p i e z ' o - e l e c t r i c c r y s t a l resonant f o r a band o f

f r e

. ' q u e n c i e s , an

‘ e l e c t r i c

c i r c u i t

f o r

generating

high

f r e q u e n c y

e l e c t r i c

c u r r e n t

c o u p l e d w i t h s a i d

c r y s

t a l and t u n e d t o

o s c i l l a t e

a t

a

f r e q u e n c y w i t h i n

s a i d

b a n d , s o t h a t t h e c r y s t a l i s

c a u s e d

t o v i b r a t e

a t

high f r e q u e n c y ,

and means f o r

a p p l y i n g

v a r i a

t i o n s o f p r e s s u r e t o s a i d c r y s t a l s o a s t o

a c t

o n

t h e

a m p l i t u d e

o f

t h e

v i br a t i o n s t h e r e o f

whereby

e l e c t r i c

v a r i a t i o n s

a r e produced

i n

s a i d e l e c t r i c ‘

-

c i r c u i t . the

dimension

o f

the c r y s t a l

i n

the d i

r e c t i o n i n which i t v i b r a t e s

b e i n g

n o n - u n i f o r m

a l o n g

t h e

s u r f a c e o f s a i d

c r y s t a l .

5

1 5

20

25

30

3 5

6 5

U.S. Patent 2,096,106, entitled "Transforming pressure variations into electrical variations" issued 1937.

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