Powder cloud generating apparatus

Claim 1

IN AN APPARATUS FOR DEVELOPING AN ELECTROSTATIC IMAGE ON A RECORDING ELEMENT WITH A CLOUD OF TONER PARTICLES OF PREDOMINANTLY ONE POLARITY OF ELECTRIC CHARGE FROM A DEVELOPER MIXTURE OF MAGNETIC PARTICLES AND TONER POWDER, SAID MAGNETIC PARTICLES AND SAID PARTICLES OF TONER POWDER EXHIBITING A TRIBOELECTRIC EFFECT; THE IMPROVEMENT COMPRISING: MAGNETIC POLE MEANS PROVIDING A MAGNETIC FIELD, MEANS INCLUDING POSITIVE AND NEGATIVE ELECTRODES COOPERATING WITH SAID FIRST NAMED MEANS TO PROVIDE AN ELECTROSTATIC FIELD COINCIDENT WITH SAID MAGNETIC FIELD, ONE OF SAID ELECTRODES COMPRISING AT LEAST PART OF SAID MAGNETIC POLE MEANS; AN ENDLESS WEB OF INSULATING MATERIAL, MEANS TO MOVE SAID ENDLESS WEB OF INSULATING MATERIAL SUBSTANTIALLY PREPENDICULAR TO SAID FIELDS WITH ONE SURFACE OF SAID WEB IN CONTACT WITH A QUANTITY OF SAID DEVELOPER MIXTURE SUPPORTED IN SAID FIELDS BETWEEN SAID SURFACE AND SAID ONE OF SAID ELECTRODES; BLOWER MEANS ADJACENT TO SAID WEB TO BLOW PARTICLES OF SAID TONER POWDER ADHERING TO PORTIONS OF SAID WEB TO FORM A CLOUD AFTER SAID PORTIONS HAVE PASSED THROUGH SAID FIELDSF AND, A CHAMBER COMUNICATING WITH SAID BLOWER MEANS TO RECEIVE SAID CLOUD FOR DEVELOPMENT OF SAID ELECTROSTATIC IMAGE THEREWITH.