Printhead Substrate High-Density Electrothermal Transducer Array
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inkjet printheads face challenges in achieving high-quality printing while maintaining high printing speed, as reducing ink droplet size increases the number of heaters required, leading to a larger printhead size and increased vibration and noise, and the time-division driving method limits simultaneous heater activation to prevent voltage drops.
Innovation Solution
A printhead substrate with an electrothermal transducer array and a time-division driving circuit, where electrothermal transducers are grouped and connected to common and individual wirings, allowing for higher density arrangement of heaters while reducing line width, enabling both high-quality and high-speed printing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the number of heaters is doubled to maintain ink discharge amount with reduced droplet size, then printing quality is improved, but the size of the printhead substrate is increased
Solution Approach 1:
The patent merges multiple heater control functions into shared power supply wirings. By grouping heaters and using common wirings for multiple heaters, the substrate area is reduced while maintaining the required number of heaters for high printing quality.
Solution Approach 2:
The patent introduces time-division driving to add a temporal dimension to heater control. By driving heaters sequentially rather than simultaneously, the system can use fewer heaters active at any given moment, reducing the required substrate area while maintaining printing quality through cumulative ink deposition.
2Productivity
If the heater pitch is reduced to increase heater density, then printing speed is improved, but the line width and spacing requirements become more difficult to satisfy
Solution Approach 1:
The patent combines power supply wirings for multiple heaters into shared common wirings. This merging reduces the total number of individual wiring lines required, making fabrication easier even at reduced heater pitch and higher density.
Solution Approach 2:
The common wirings serve multiple functions by powering multiple heaters simultaneously or sequentially. This multi-functionality reduces the wiring infrastructure requirements, easing manufacturing constraints at high heater densities.
3Productivity
If all heaters are driven at the same time, then printing speed is maintained, but voltage drop due to line resistance increases
Solution Approach 1:
The patent implements time-division driving where heaters are activated in periodic sequences rather than all at once. This periodic activation pattern maintains printing speed by ensuring continuous ink deposition while limiting simultaneous current draw to prevent voltage drops.
Solution Approach 2:
The patent segments heater operation into time-divided groups. By dividing the heater array into groups that are driven sequentially, the system maintains high printing speed through continuous operation while preventing voltage instability caused by simultaneous full-array activation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration allows for higher quality and higher speed printing by ensuring a sufficient area for each electrothermal transducer, enabling downsizing of the printhead substrate and printhead while maintaining stable ink discharge.
Implementation Method 1
electrothermal transducers (heaters) to generate thermal energy for discharging ink
Data Source
AI summary
Plural electrothermal transducers (heaters) belonging to each of blocks having different driving timings are constituted as one group and are connected to a common interconnecting wiring in units of one group. Plural lines are connected to the common wiring such that the plural lines are extended to return with respect to the heaters and are each arranged to extend in an adjacent or sandwiched relation to the heaters. A printhead substrate, a printhead, and a printing apparatus can be provided which can realize higher quality of a printed image and a higher printing speed by arraying the heaters at a higher density while ensuring a sufficient area for arrangement of each of the heaters.