Electrostatic recording

Claim 1

AN ELECTRICALLY CONDUCTIVE INK FOR USE IN THE DEVELOPMENT OF ELECTROSTATIC LATENT IMAGES; SAID INK COMPRISING NON-FRIABLE GLASS PARTICLES HAVING SUBSTANTIALLY 100% OF THE PARTICLES WITHIN THE RANGE OF FROM 10 TO 80 MICRONS IN DIAMETER AND COATED WITH AN OPAQUE ELECTRICALLY CONDUCTIVE METAL MATERIAL OF THE ORDER OF 1 MILLIONTH OF AN INCH THICK, THE BULK ELECTRICAL RESISTANCE OF SAID INK BEING LESS THAN 1O,000 OHMS AND THE SPECIFIC GRAVITY OF THE PARTICLES BEING SUBSTANTIALLY NOT GREATER THAN FOUR, SAID METAL OF SAID COATING BEING CHOSEN FROM THE GROUP CONSISTING OF SILVER, COPPER, GOLD, PALLADIUM AND RHODIUM.

Claim 3

THE METHOD OF MAKING COPIES OF A MESSAGE WHICH COMPRISING ESTABLISHING ELECTROSTATIC LATENT IMAGES OF THE MESSAGE ON THE CHARGE RETENTIVE SURFACE OF A RECORDING MEDIUM, DEVELOPING THE SAID ELECTROSTATIC LATENT IMAGES BY SUBJECTING THE RECORDING MEDIUM TO A MASS OF NORMALLY NON-CRUSHABLE INK PARTICLES HAVING AN ATTRACTION FOR THE ELECTROSTATICALLY CHARGED AREAS OF THE MEDIUM TO THUS CAUSE SUCH PARTICLES TO FORM A LIGHTLY ADHERING COATING THEREOVER; AND SUBSTANTIALLY SIMULTANEOUSLY (1) PERMANENTLY FIXING THE DEVELOPED LATENT IMAGES TO THE SAID RECORDING MEDIUM; AND (2) MAKING COPIES OF THE SAID DEVELOPED AND FIXED IMAGES BY BRINGING THE SAID RECORDING MEDIUM BEARING SAID DEVELOPED AND FIXED IMAGES IN JUXTAPOSITION WITH COPY PAPER ASSOCIATED WITH MEANS FOR PRODUCING LOCALIZED VISIBLE MARKS ON SAID COPY PAPER IN AREAS COINCIDENT WITH THE APPLICATION TO SAID MARK PRODUCING MEANS AND SAID COPY PAPER OF LOCALIZED PRESSURE; AND SUBJECTING SAID JUXTAPOSED COMBINATION OF IMAGEBEARINNG RECORDING MEDIUM AND COPY PAPER TO MECHANICAL CONSTRICTION IN A DIRECTION SUBSTANTIALLY NORMAL TO THE PLANE OF SAID JUXTAPOSED COMBINATION AT THE POINT OF SAID CONSTRUCTION, SAID CONSTRICTION BEING OF SUCH OPENING SIZE AS TO PRODUCE IN THE AREAS OF ATTACHMENT OF SAID INK PARTICLES LOCALIZED PRESSURE SUFFICIENT TO CAUSE SAID MARK PRODUCING MEANS TO PRODUCE VISIBLE MARKS ON SAID COPY PAPER IN SAID AREA, BUT TO PERMIT THE PRESENCE IN SAID CONSTRICTION OF SAID JUXTAPOSED COMBINATION WITHOUT THE PRODUCTION OF MARK-PRODUCING PRESSURE IN AREAS WHERE NO SAID INK PARTICLES ARE PRESENT.

Claim 4

THE METHOD OF MAKING COPIES OF A MESSAGE WHICH COMPRISING ESTABLISHING ELECTROSTATIC LATENT IMAGES OF THE MESSAGE ON THE CHARGE RETENTIVE SURFACE OF A RECORDING MEDIUM, DEVELOPING THE SAID ELECTROSTATIC LATENT IMAGES BY SUBJECTING THE RECORDING MEDIUM TO A MASS OF NORMALLY NON-CRUSHABLE INK PARTICLES HAVING AN ATTRACTION FOR THE ELECTROSTATICALLY CHARGED AREAS OF THE MEDIUM TO THUS CAUSE SUCH PARTICLES TO FORM A LIGHTLY ADHERING COATING THEREOVER; AND SUBSTANTIALLY SIMULTANEOUSLY (1) PERMANENTLY FIXING THE DEVELOPED LATENT IMAGES TO THE SAID RECORDING MEDIUM; AND (2) MAKING COPIES OF THE SAID DEVELOPED AND FIXED IMAGES BY BRINGING THE SAID RECORDING MEDIUM BEARING SAID DEVELOPED AND FIXED IMAGES IN JUXTAPOSITION WITH COPY PAPER ASSOCIATED WITH MEANS FOR PRODUCING LOCALIZED VISIBLE MARKS ON SAID COPY PAPER IN AREAS COINCIDENT WITH THE APPLICATION TO SAID MARK PRODUCING MEANS AND SAID COPY PAPER OF LOCALIZED PRESSURE; AND SUBJECTING SAID JUXTAPOSED COMBINATION OF IMAGEBEARINNG RECORDING MEDIUM AND COPY PAPER TO MECHANICAL CONSTRICTION IN A DIRECTION SUBSTANTIALLY NORMAL TO THE PLANE OF SAID JUXTAPOSED COMBINATION AT THE POINT OF SAID CONSTRUCTION, SAID CONSTRICTION BEING OF SUCH OPENING SIZE AS TO PRODUCE IN THE AREAS OF ATTACHMENT OF SAID INK PARTICLES LOCALIZED PRESSURE SUFFICIENT TO CAUSE SAID MARK PRODUCING MEANS TO PRODUCE VISIBLE MARKS ON SAID COPY PAPER IN SAID AREA, BUT TO PERMIT THE PRESENCE IN SAID CONSTRICTION OF SAID JUXTAPOSED COMBINATION WITHOUT THE PRODUCTION OF MARK-PRODUCING PRESSURE IN AREAS WHERE NO SAID INK PARTICLES ARE PRESENT.