Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
174 words
Apparatus for maintaining a predetermined ink temperature profile throughout a multiple-orifice, phase-change ink-jet print head, the print head losing heat at different rates from a set of regions distributed along multiple axes of the print head, the print head ejecting molten phase-change ink by the action of piezoelectric transducers, comprising: a temperature sensor electrically connected to a temperature controller and thermally connected to the print head; and a print head heater electrically connected to the temperature controller, the print head heater having multiple heating zones each in thermal communication with a corresponding region of the print head to maintain the molten phase-change ink in a liquid state at a predetermined ink temperature profile, the heating zones having a proportional watt-density that compensates for the rates of heat loss from each of the regions to maintain the predetermined ink temperature profile throughout the print head to obtain substantially uniform ink drop ejection velocity by maintaining the ink across the orifice array at substantially the same viscosity and the print head orifice array being substantially media-width.
Claim 2
Dependent Claim
174 words
Apparatus for maintaining a predetermined ink temperature profile throughout a multiple-orifice, phase-change ink-jet print head, the print head losing heat at different rates from a set of regions distributed along multiple axes of the print head, the print head ejecting molten phase-change ink by the action of piezoelectric transducers, comprising: a temperature sensor electrically connected to a temperature controller and thermally connected to the print head; and a print head heater electrically connected to the temperature controller, the print head heater having multiple heating zones each in thermal communication with a corresponding region of the print head to maintain the molten phase-change ink in a liquid state at a predetermined ink temperature profile, the heating zones having a proportional watt-density that compensates for the rates of heat loss from each of the regions to maintain the predetermined ink temperature profile throughout the print head to obtain substantially uniform ink drop ejection velocity by maintaining the ink across the orifice array at substantially the same viscosity and the print head orifice array being substantially media-width.
Claim 3
Dependent Claim
16 words
The apparatus of claim 1 in which the predetermined ink temperature profile is a substantially uniform.
Claim 4
Dependent Claim
25 words
The apparatus of claim 1 in which the heating zones are distributed along an X-dimension spanning substantially a width of a print head orifice array.
Claim 5
Dependent Claim
18 words
The apparatus of claim 3 in which the print head orifice array width is at least 24 centimeters.
Claim 6
Dependent Claim
29 words
The apparatus of claim 1 in which the heating zones are distributed along an X-dimension and a Y-dimension substantially spanning a respective width and height of the print head.
Claim 7
Dependent Claim
31 words
The apparatus of claim 1 in which the heating zones are distributed obliquely along an X-dimension and a Y-dimension substantially spanning a respective width and a height of the print head.
Claim 8
Dependent Claim
37 words
The apparatus of claim 1 in which the print head heater is shaped such that the heating zones are distributed around a perimeter of an area that is in thermal communication with a print head orifice array.
Claim 9
Dependent Claim
32 words
The apparatus of claim 1 in which the print head heater is shaped such that the heating zones are distributed throughout an area that is in thermal communication with an orifice array.
Claim 10
Dependent Claim
24 words
The apparatus of claim 1 in which the heating zones are proportioned to provide a uniformly tapered watt-density distribution in the print head heater.
Claim 11
Dependent Claim
27 words
The apparatus of claim 1 in which the print head heater is of unitary construction and is the only heater in thermal contact with the print head.
Claim 12
Dependent Claim
25 words
The apparatus of claim 1 in which the print head heater is separated from direct thermal contact with the print head by an intervening substrate.
Claim 13
Dependent Claim
63 words
The apparatus of claim 1 in which the print head heater is constructed as a flexible composite laminate having at least one resistance foil heater element that is formed of multiple line portions defined by line-widths and line-spacings between them, either the line-widths or the line-spacings being of varying size to achieve a predetermined electrical resistance value in each of the heating zones.
Claim 14
Dependent Claim
22 words
The apparatus of claim 1 in which the temperature controller drives the print head heater with a pulse duration modulated electrical voltage.
Claim 15
Dependent Claim
16 words
The apparatus of claim 13 in which the electrical voltage is an alternating current power-line voltage.
Claim 16
Dependent Claim
22 words
The apparatus of claim 1 in which the temperature sensor is the only temperature sensor in thermal contact with the print head.
Claim 17
Dependent Claim
26 words
The apparatus of claim 1 in which the temperature sensor is in thermal contact with a substantially central location along an X-axis of the print head.
Claim 18
Dependent Claim
20 words
The apparatus of claim 1 in which the temperature sensor is a thermistor that is embedded in the print head.
Claim 19
Dependent Claim
25 words
The apparatus of claim 1 in which the temperature sensor is of a chip-type that is surface-mounted to a major surface of the print head.
Claim 20
Dependent Claim
35 words
The apparatus of claim 1 in which the temperature sensor, temperature controller, and print head heater comprise components of a print head temperature control loop that has a thermal response time not exceeding ten seconds.
Claim 21
Dependent Claim
20 words
The apparatus of claim 19 in which the thermal response time has a range of from one to seven seconds.
Claim 22
Independent Claim
171 words
A method for maintaining a uniform ink temperature throughout an orifice array width of a substantially media-width, phase-change ink-jet print head, the print head losing heat at different rates from a set of regions located throughout the orifice array width of the print head, comprising the steps of: sensing the temperature of the print head; communicating the sensed temperature to a temperature controller; controlling a substantially media-width print head heater that is thermally connected to the print head; and partitioning the print head heater into multiple differential heating zones each in thermal communication with a corresponding region of the print head, the differential heating zones compensating for the different rates of heat loss from the set of regions to maintain a uniform molten phase-change ink temperature throughout the orifice array width of the print head to obtain a substantially uniform drop ejection velocity of the phase-change ink from the orifice array by the action of the piezoelectric transducers by maintaining the ink across the orifice array at substantially the same viscosity.
Claim 23
Independent Claim
171 words
A method for maintaining a uniform ink temperature throughout an orifice array width of a substantially media-width, phase-change ink-jet print head, the print head losing heat at different rates from a set of regions located throughout the orifice array width of the print head, comprising the steps of: sensing the temperature of the print head; communicating the sensed temperature to a temperature controller; controlling a substantially media-width print head heater that is thermally connected to the print head; and partitioning the print head heater into multiple differential heating zones each in thermal communication with a corresponding region of the print head, the differential heating zones compensating for the different rates of heat loss from the set of regions to maintain a uniform molten phase-change ink temperature throughout the orifice array width of the print head to obtain a substantially uniform drop ejection velocity of the phase-change ink from the orifice array by the action of the piezoelectric transducers by maintaining the ink across the orifice array at substantially the same viscosity.
Claim 24
Dependent Claim
59 words
The method of claim 21 in which the print head loses heat at different rates from a set of regions located throughout the orifice array width and height, and the differential heating zones compensate for the different rates of heat loss from the set of regions, thereby maintaining a uniform ink temperature throughout the orifice array width and height.
Claim 25
Dependent Claim
20 words
The method of claim 21 in which the print head has an orifice array width of at least 24 centimeters.