Print Head Driver Circuit With Tristate Waveform Control

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Solution Overview

Problem

Existing drive circuits for ink jet printers with piezo-electric actuators require multiple power sources and switches to generate complex waveforms, leading to increased costs and complexity in ASICs.

Innovation Solution

An electronic circuit with analog drivers capable of switching to a tristate condition, using internal capacitive loads to maintain voltage levels, reducing the need for additional power sources and enabling complex waveforms without increasing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple power sources and switches are used to generate complex waveforms, then waveform control precision is improved, but device complexity and cost increase

Engineering Contradiction:

Improvewaveform control precisionVSAvoidcircuit complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple power sources into a single voltage source by combining several capacitor banks that can be selectively connected to provide different voltage levels. This reduces the number of power sources and switches while maintaining the ability to generate complex waveforms with precise voltage transitions.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The circuit uses a universal voltage source that can serve multiple functions by connecting different capacitor banks in series or parallel configurations. This single voltage source can provide various voltage levels needed for complex waveforms, eliminating the need for multiple dedicated power sources.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If multiple power sources are used to generate complex waveforms, then waveform versatility is improved, but manufacturing cost increases

Engineering Contradiction:

Improvewaveform versatilityVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The circuit achieves waveform versatility by changing the configuration parameters of the capacitor banks - specifically by switching between series and parallel connections to provide different voltage levels and current capacities, all from a single voltage source.

Inventive Principle:

Principle #35Parameter changes

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

Enables precise control of ink ejection in ink jet printers by generating complex waveforms efficiently, reducing costs and complexity while maintaining accurate timing and voltage control.

Implementation Method 1

each print element having a piezo-electric actuator that is capable of generating an acoustic wave in an ink chamber

Methodology Applied

Scientific EffectPiezo-electric effect: Piezoelectric Effect

Data Source

PatentUS12558887B2Circuit and method for driving a print head

Publication Date: 2026.02.24 CANON PRODN PRINTING HLDG BV

AI summary

An electronic circuit for driving an individual print element in a print head is disclosed. The print head comprises an array of print elements, each print element having a piezo-electric actuator that is capable of generating an acoustic wave in an ink chamber of the print element, resulting in the ejection of an ink drop out of a nozzle that is in fluid connection with the ink chamber. The electronic circuit comprises a number of analog drivers for amplifying an output current at a voltage level in-between two source voltage levels, wherein the drivers can be switched into a tristate condition at a voltage level that does not equal one of the source voltage levels.