4009385 Laser control circuit

PAT~ARCH SECTION

NEW PATENTS Th=s Secuon contains abstracts and, where appropnate, illustrations of recently ~ssued Umted'States patents and pubhshed patent apphcauons filed from over 30 countries under the Patent Cooperation Treaty This mformatmn was obtamed from recent addmons to the Pergamon PATSEARCH Ronline database m accordance w,th interest profiles developed by the Editors Further mformauon about Pergamon PATSEARCH" can be obtained from Pergamon InfoLme Inc, 1340 Old Chain Bridge Road, McLean, Vwgmm 22101 U S A Cop~es of complete patents announced m thin Section are avmlable from Pergamon lnfoLme Inc for $8 per copy Payment w~th order ~s reqmred Orders outside North America add $2 for mr postage Order by patent number for Pergamon InfoLme only

4009385

osollauon output of stud oscdlator o r c m t by 90 degrees, a mulupher clrcmt for mult,plymg an output of the phase shift o r c m t by a modulating s~gnal, and a phase adder clrcmt ]'or varymg an oscfllaUon frequency of the oscdlator clrcmt by addmg the output of the multlpher o r c m t The amphficauon elements of the phase adder clrcmt and the oscdlator o r c m t are connected m parallel w~th respect to a power source. The multtpher c~rcmt comprises an amphficauon element connected to recewe the output of the phase shift o r cmt A constant current source clrcmt is connected m sertes with the amphficahon element of the mulUpher c~rcmt and serves to vary the magmtude of current passing therethrough m accordance w~th the modulating s~gnal

LASER CONTROL CIRCUIT D A R R E L L DEAN SELL assigned to BELL TELEPHONE LABORATORIES INCORPORATED A C O N T R O L C I R C U I T FOR AN INJECTION LASER I N C L U D E S A D R I V E R CIRCUIT W H I C H APPLIES A D R I V I N G C U R R E N T TO THE LASER IN RESPONSE TO AN E L E C T R I C A L M O D U L A T I N G SIGNAL A PREBIAS C I R C U I T APPLIES A PREBIAS C U R R E N T TO THE LASER IN RESPONSE TO THE D I F F E R E N C E BETWEEN A SIGNAL D E R I V E D F R O M THE E L E C T R I C A L M O D U L A T I N G SIGNAL A N D A SIGNAL D E R I V E D FROM THE LASER LIGHT O U T P U T

4533943 VIDEOCOMMUNICATION NETWORK BETWEEN VIDEOPHONE TERMINALS AND A PICTURE BANK

4533882 FREQUENCY M O D U L A T O R WHEREIN M O D U L A T I O N T A K E S

Alam Polner, Meudon, France

PLACE IN A FEEDBACK LOOP O F A N OSCILLATOR 7,

I,~

Settaro Shmbara, Yokohama, Japan assigned to Tokyo Shlbaura Denkl Kabushlkt Kmsha etnr~[~

2

a.r~rt~

-

~2

P

~

'

22 Z3 ~

~a P H * S (

~~.~_~

~111 I

-

:~'~ - ~ - --~- - ~ ,-T~ ~ c ~. , ~ ,.,. ,~

-~

....,'_~

' z~", ~O~Sr~r cu~R~vr

.Q

-.

6UFU(R souse[ cr~ulr

vldeocommumcatlon network is connected between videophone terminals and a picture bank through voice swltchmg umts and wideband swttchmg umts included m central offices A

A frequency modulator comprises an oscdlator orcmt, a phase shift o r c m t for phase-shifting an TELEMATICS and INFORMATICS

Vol 3, No 1, pp V-Xl, 1986 Copynght E, 1986 Pergamon Journals Lid Prmted m USA 0736o5853/86 $3 00 + 00 V