Ink jet head with ink usage sensor

Claim 2

An ink jet system comprising ink jet head means for jetting ink including an ink supply, an array of orifices, transducer means for causing selective ejection of ink drops through the orifices, counter means for counting the drops ejected through the orifices, nonvolatile memory means including means for storing a number corresponding to the number of drops ejected through the orifices in the ink jet head means and to indicate appropriate action when the number of drops exceeds a selected number and reset means for resetting the nonvolatile memory means upon replenishment of the ink supply.

Claim 3

An ink jet system according to claim 1 further comprising support means for supporting the ink jet head means and a substrate for relative motion between the ink jet head means and the substrate so as to produce an image on the substrate during operation of the system, an ink reservoir in the ink jet heat means, and control means including means for causing relative motion between the ink jet head means and the substrate and means for supplying control signals to the transducer means to cause ejection of ink through the array of orifices, wherein the ink jet head means is removably mounted on the support means and wherein the means for storing a number corresponding to the number of drops ejected through the orifices in the ink jet head means permits removal of the ink jet head means from the system without loss of ink usage information.

Claim 4

An ink jet system according to claim 2 including counter control means arranged to initiate counting by the counter means only when a security arrangement has been activated.

Claim 5

An ink jet system according to claim 3 wherein the counter means is included in the ink jet head means and the security arrangement includes means for setting the nonvolatile memory means using a special code.

Claim 6

An ink jet system according to claim 2 wherein the control means is arranged to permit completion of printing of a substrate following detection of the signal indicating the predetermined number in the nonvolatile memory.

Claim 7

An ink jet system according to claim 2 wherein the support means supports the ink jet head for motion during ejection of ink from the orifices in the ink jet head means.

Claim 8

An ink jet system according to claim 2 wherein the ink jet head is removably supported on the support means to permit replacement of the ink jet head means.

Claim 9

An ink jet head for use in an ink jet system comprising an ink supply, an array of orifices, transducer means for causing selective ejection of ink drops through the orifices in response to control signals, counter means for counting the drops ejected through the orifices in the array, nonvolatile memory means including means for storing a number corresponding to the number of drops ejected through the orifices in the array and reset means for resetting the non-volatile memory means upon replenishment of the ink supply.

Claim 10

An ink jet head for use in an ink jet system comprising an ink supply, an array of orifices, transducer means for causing selective ejection of ink drops through the orifices in response to control signals, counter means for counting the drops ejected through the orifices in the array, nonvolatile memory means including means for storing a number corresponding to the number of drops ejected through the orifices in the array and reset means for resetting the non-volatile memory means upon replenishment of the ink supply.

Claim 11

An ink jet head according to claim 8 wherein the ink jet head is adapted to be removably mounted on a support, and further comprising a refillable ink reservoir, a supply of hot melt ink in the reservoir, wherein the nonvolatile memory permits removal of the ink jet head from an ink jet system without loss of information stored in the memory, and wherein the counter means supplies ink usage information to the nonvolatile memory.

Claim 12

An ink jet system comprising support means for supporting an ink jet head and a substrate for relative motion between the ink jet head and the substrate so as to produce an image on the substrate during operation of the system, ink jet head means for jetting ink including an ink reservoir, an array of orifices and transducer means for causing selective ejection of ink drops through the orifices in response to control signals, control means including means for causing relative motion between the ink jet head means and the substrate and means for supplying control signals to the transducer means to cause ejection of ink through the array of orifices, counter means for counting the drops ejected through the orifices, nonvolatile memory means including means for storing a number corresponding to the number of drops ejected through the orifices in the ink jet head means and means for producing a signal to indicate appropriate action when the number of drops ejected through the orifices reaches or exceeds a predetermined number, and counter control means arranged to initiate counting by the counter means only when a security arrangement has been activated, wherein the security means includes a resettable polarizable element in the ink jet head means and means for setting a selected polarization condition of the polarizable element in response to replenishment of ink in the ink reservoir and wherein the counter means and nonvolatile memory means are included in the control means and wherein the control means includes means for resetting the nonvolatile memory means in response to detection of the polarizable element in the ink jet head means and for altering the polarization condition of the polarizable element when the nonvolatile memory means is reset.

Claim 13

An ink jet system comprising support means for supporting an ink jet head and a substrate for relative motion between the ink jet head and the substrate so as to produce an image on the substrate during operation of the system, ink jet head means for jetting ink including an ink reservoir, an array of orifices and transducer means for causing selective ejection of ink drops through the orifices in response to control signals, control means including means for causing relative motion between the ink jet head means and the substrate and means for supplying control signals to the transducer means to cause ejection of ink through the array of orifices, counter means for counting the drops ejected through the orifices, nonvolatile memory means including means for storing a number corresponding to the number of drops ejected through the orifices in the ink jet head means and means for producing a signal to indicate appropriate action when the number of drops ejected through the orifices reaches or exceeds a predetermined number, and counter control means arranged to initiate counting by the counter means only when a security arrangement has been activated, wherein the security means includes a resettable polarizable element in the ink jet head means and means for setting a selected polarization condition of the polarizable element in response to replenishment of ink in the ink reservoir and wherein the counter means and nonvolatile memory means are included in the control means and wherein the control means includes means for resetting the nonvolatile memory means in response to detection of the polarizable element in the ink jet head means and for altering the polarization condition of the polarizable element when the nonvolatile memory means is reset.

Claim 14

An ink jet system according to claim 10 wherein the polarizable element is a portion of the transducer means used for ejection of drops from the ink jet head means.

Claim 15

An ink jet head for use in a hot melt ink jet system adapted to be removably mounted on a support, comprising a refillable ink jet head including an ink reservoir, a supply of hot melt ink in the reservoir, an array of orifices and transducer means for causing selective ejection of hot melt ink through the orifices in response to control signals, including a resettable polarizable element in the ink jet head and means for setting a selected polarization condition in the polarizable element for indicating a full status of the hot melt ink supply in the reservoir.

Claim 16

An ink jet head for use in a hot melt ink jet system adapted to be removably mounted on a support, comprising a refillable ink jet head including an ink reservoir, a supply of hot melt ink in the reservoir, an array of orifices and transducer means for causing selective ejection of hot melt ink through the orifices in response to control signals, including a resettable polarizable element in the ink jet head and means for setting a selected polarization condition in the polarizable element for indicating a full status of the hot melt ink supply in the reservoir.

Claim 17

An ink jet head according to claim 12 wherein the polarizable element is a portion of the transducer means for causing selective ejection of hot melt ink through the orifices in response to control signals.