Multi-Zone Thermal Control for Print Die Uniformity

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Solution Overview

Problem

Thermal ink jet printing is sensitive to operating temperature variations, leading to differences in ink drop size and quality, particularly in devices with thin or narrow silicon dies that are more susceptible to temperature fluctuations, resulting in poor print quality and banding issues.

Innovation Solution

A multi-zone thermal control system with a shared analog sensor bus and external ASIC control, using multiple temperature sensors and heating elements to maintain thermal uniformity across the print die, with sensors and heaters strategically placed to minimize temperature differentials and optimize heat transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple temperature sensors and heating elements are added to achieve thermal uniformity, then print quality is improved, but device complexity increases

Engineering Contradiction:
Improveprint qualityVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The print die is divided into multiple temperature zones (first temperature zone, second temperature zone, third temperature zone) with independent temperature sensors and heating elements in each zone. This segmentation allows independent thermal control of different regions, enabling precise temperature management to eliminate banding while maintaining manageable system complexity through modular zone-based architecture

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the print die are assigned different thermal control characteristics. The first, second, and third temperature zones have independently controllable heating elements and sensors, allowing each zone to be optimized for its specific thermal requirements. This local quality approach enables precise temperature control in each region while using a shared analog bus to reduce overall system complexity

Inventive Principle:
Principle #3Local quality

2Device complexity

If a shared analog sensor bus is used to reduce device complexity, then manufacturing cost is reduced, but measurement precision may be compromised

Engineering Contradiction:
Improvedevice complexityVSAvoidtemperature measurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The shared analog sensor bus implements periodic multiplexing where temperature sensors in different zones are sequentially connected to the bus rather than simultaneously. The controller sequentially selects and reads from different temperature sensors at different time periods, allowing multiple sensors to share a single analog bus without signal interference. This periodic action maintains measurement precision while significantly reducing device complexity and manufacturing cost

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

A controller acts as an intermediary between the temperature sensors and the analog bus. The controller manages the sequential connection and data reading from different temperature sensors, ensuring that each sensor's measurement is accurately captured and transmitted through the shared bus. This intermediary approach enables multiple sensors to share the bus without compromising measurement precision

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If heating elements are added to end zones to compensate for heat loss, then temperature uniformity is improved, but energy consumption increases

Engineering Contradiction:
Improvetemperature uniformityVSAvoidenergy consumption
Core Design Contradiction:
Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

Temperature sensors in each zone continuously monitor the actual temperature, and the controller uses this feedback to dynamically adjust the heating elements. The controller reads temperature data from sensors, compares it with target temperatures, and adjusts heating power accordingly. This feedback mechanism ensures temperature uniformity while minimizing energy consumption by applying heat only where and when needed

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes heating parameters (power level, pulse width modulation duty cycle) based on real-time temperature conditions. The controller adjusts heating element characteristics according to the measured temperature deviations in each zone, enabling precise thermal control with minimal energy expenditure. This parameter optimization allows the system to maintain temperature uniformity while reducing overall energy consumption

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

This approach reduces temperature differentials across the nozzle array from 10°C to 2-3°C, significantly improving print quality by eliminating banding and ensuring consistent ink delivery.

Implementation Method 1

A first temperature sensor can be located in a first region of integrated circuitry 106 and a second temperature sensor can be located in a second region of the integrated circuitry 106

Methodology Applied
Scientific EffectTemperature sensing:

Implementation Method 2

The heat generated can be transferred to the printing device itself causing temperature on the die to vary

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

The heat generated through the printing process can be unevenly distributed along the printing device

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3710267B1Temperature detection and control
Publication Date: 2024.03.27 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3710267B1 patent drawingFigure 1
  • EP3710267B1 patent drawingFigure 2
  • EP3710267B1 patent drawingFigure 3

AI summary

A print component integrated circuitry package includes a number of temperature sensors where each of the plurality of the temperature sensors is disposed in a corresponding temperature region of an integrated circuitry. In an example, an analog sense bus conductively connects to all of the plurality of temperature sensors and an external sensor pad that is to connect to a corresponding print controller contact.