High drop generator density printhead
AssigneeHewlett-Packard Company
InventorsRama Prasad, Todd A. Cleland, Robert C. Maze, Dale R. Oughton
Life of this patent
Estimating the term…
Abstract
A thermal inkjet printing apparatus employs a segmented heater resistor, a thin passivation layer, and a lower heater resistor activation energy to realize a high density drop generator printhead.
Claims16
A high density drop generator inkjet printhead realizing at least 1200 dpi in at least one direction of printing comprising:
- a semiconductor substrate with at least one surface, said surface having a predetermined area;
- a multiplicity of heater resistors disposed on said at least one surface at a density of at least six heater resistors per square millimeter and each heater resistor adapted to eject an ink drop when an energy pulse between 1.0 and 1.4 .mu.joules is applied;
- and
- a passivation layer disposed on a portion of said at least one surface of said semiconductor substrate to a thickness having a range of between 3350 .ANG. and 4350 .ANG. over each of said multiplicity of heater resistors thereby avoiding damaging printhead temperatures.
A thermal inkjet printing apparatus providing at least a 1200 dpi deposition of ink dots in at least one direction of printing on a medium comprising:
- a processor that selects a predetermined number of drop generators to place ink dots on the medium;
- a power supply that provides a pulse of electrical energy to said predetermined number of drop generators;
- a print cartridge comprising a supply of ink and a multiplicity of drop generators in a printhead from which said predetermined number of drop generators is selected, said printhead further comprising:
- a semiconductor substrate with at least one surface, said surface having a predetermined area;
- a multiplicity of heater resistors disposed on said at least one surface at a density of at least six heater resistors per square millimeter, corresponding to said multiplicity of drop generators and each heater resistor adapted to eject an ink drop when an energy pulse between 1.0 and 1.4 .mu.Joules is applied;
- and
- a passivation layer disposed on a portion of said at least one surface of said semiconductor substrate to a thickness having a range of between 3350 .ANG. and 4350 .ANG. over each of said multiplicity of heater resistors thereby avoiding damaging printhead temperatures.
A method of operation of a thermal inkjet printing apparatus that includes a processor to select a predetermined number of drop generators to place ink dots on a medium, a power supply to supply power to the predetermined number of drop generators, and a substrate supporting a predetermined number of heater resistors associated with the predetermined number of drop generators, comprising the step of:
- supplying voltage within a range of 10.7 Volts to 10.9 Volts for a pulse time within the range of 1.3 .mu.sec to 1.5 .mu.sec to the substrate for a heater resistor of the predetermined number of heater resistors to eject a drop of ink.
A high density drop generator inkjet printhead comprising:
- a semiconductor substrate with at least one surface, said surface having a predetermined area upon which is disposed a multiplicity of heater resistors at a density of at least six heater resistors per square millimeter, each heater resistor of said multiplicity of heater resistors further comprising two series coupled resistive segments and each heater resistor of said multiplicity of heater resistors further comprising a resistive planar sheet having a resistivity range of between 27.1 .OMEGA./square and 31.5 .OMEGA./square at least one of said two series coupled resistive segments comprising a range of length dimensions between 20.5 .mu.m and 24.0 .mu.m, and said at least one of said two series coupled resistive segments comprising a range of width dimensions between 9.0 .mu.m and 11.0 .mu.m;
- and
- a passivation layer disposed on a portion of said at least one surface of said semiconductor substrate to a thickness having a range of between 3350 .ANG. and 4350 .ANG. over each of said multiplicity of heater resistors.
A thermal inkjet printing apparatus providing a high density deposition of ink dots on a medium comprising:
- a processor that selects a predetermined number of drop generators to place ink dots on the medium;
- a power supply that provides a pulse of electrical energy to said predetermined number of drop generators;
- a print cartridge comprising a supply of ink and a multiplicity of drop generators in a printhead from which said predetermined number of drop generators is selected, said printhead further comprising:
- a semiconductor substrate with at least one surface, said surface having a predetermined area upon which is disposed a multiplicity of heater resistors at a density of at least six heater resistors per square millimeter and corresponding to said multiplicity of drop generators, each heater resistor of said multiplicity of heater resistors further comprising two series coupled resistive segments and each heater resistor of said multiplicity of heater resistors further comprising a resistive planar sheet having a resistivity range of between 27.1 .OMEGA./square and 31.5 .OMEGA./square, at least one of said two series coupled resistive segments comprising a range of length dimensions between 20.5 .mu.m and 24.0 .mu.m, and said at least one of said two series coupled resistive segments comprising a range of width dimensions between 9.0 .mu.m and 11.0 .mu.m;
- and
- a passivation layer disposed on a portion of said at least one surface of said semiconductor substrate to a thickness having a range of between 3350 .ANG. and 4350 .ANG. over each of said multiplicity of heater resistors.
Dependencies are inferred from the claim text.