Inkjet Printer Head Temperature Estimation for Print Density

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

At high printing speeds, the time available for detecting and adjusting the drive voltage of a liquid discharge head is insufficient, leading to fluctuations in print density and deteriorated image quality due to incomplete voltage adjustments.

Innovation Solution

A liquid discharge apparatus with a temperature sensor and controller that estimates the head temperature based on discharge history and actual temperature data from a downstream gap, allowing for voltage waveform adjustments before the nozzle faces the printing area, ensuring consistent print density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the printing speed is increased, then the productivity is improved, but the time for detecting temperature and adjusting drive voltage is insufficient, causing print density fluctuation and image quality deterioration

Engineering Contradiction:

Improveprinting speedVSAvoidtime for temperature detection and voltage adjustment

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The system performs preliminary temperature detection at a downstream position (second gap) before the head reaches the first gap where printing occurs. This allows the controller to estimate the temperature at the critical printing moment and adjust the drive voltage in advance, ensuring proper print density is achieved without compromising printing speed

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediate measurement position (second gap downstream of first gap) as a mediator for temperature detection. This intermediate position provides sufficient lead time for temperature measurement and voltage adjustment while maintaining high printing speed, effectively bridging the time gap between temperature detection and voltage adjustment requirements

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the drive voltage is adjusted during printing on a recording medium, then the head temperature change is compensated, but the print density changes during printing and image quality is deteriorated

Engineering Contradiction:

Improvehead temperature compensationVSAvoidprint density consistency

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The controller adjusts the drive voltage in advance during the medium gap period before the head reaches the printing position. This preliminary adjustment ensures that when printing commences, the drive voltage is already optimized for the current head temperature, maintaining consistent print density without mid-printing fluctuations

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system performs preliminary counter-adjustment of the drive voltage to compensate for anticipated temperature changes before they affect print density. By adjusting the voltage during the gap period based on detected temperature trends, the system prevents print density deviation rather than correcting it after the fact

Inventive Principle:

Principle #9Preliminary anti-action

3Measurement precision

If the temperature detection is performed constantly, then the drive voltage adjustment accuracy is improved, but the time for voltage adjustment may be insufficient at high printing speeds

Engineering Contradiction:

Improvetemperature detection accuracyVSAvoidtime for voltage adjustment completion

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The system performs temperature detection at a downstream position (second gap) in advance of the printing position (first gap). This preliminary detection provides sufficient time for the controller to process the temperature data and adjust the drive voltage before the head reaches the printing zone, ensuring both accurate measurement and timely adjustment at high printing speeds

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The downstream second gap serves as an intermediary measurement position that provides the necessary time buffer between temperature detection and voltage adjustment. This intermediate position allows the system to maintain constant temperature monitoring accuracy while ensuring the adjustment process completes before printing begins

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS8991961B2Liquid discharge apparatus, method and storage medium for computer-readably storing program therein

Publication Date: 2015.03.31 BROTHER KOGYO KK

AI summary

An inkjet printer includes a liquid discharge head, a temperature sensor, and a controller. The controller changes a voltage waveform to be input to the ink discharge head, while a nozzle surface is facing a first gap. The temperature sensor measures a first actual temperature of the ink discharge head, while the nozzle surface is facing a second gap. The controller calculates, on the basis of the first actual temperature and a discharge history of ink discharged to a sheet located between the first gap and the second gap, a first estimated temperature of the ink discharge head corresponding to the time in which the nozzle surface is facing the first gap. The controller changes the voltage waveform on the basis of the first estimated temperature.