Inkjet Head Protrusion Damage Detection via Thermal Feedback
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Solution Overview
Problem
The existing recording apparatuses with protrusions at the ejection ports face challenges in detecting damage to these protrusions, leading to deteriorated recording quality due to the generation of satellite droplets when the protrusions are damaged, and it is difficult to prevent this damage from affecting the printing process.
Innovation Solution
A recording apparatus equipped with a liquid ejection head that includes a temperature detection element to monitor the temperature changes after a heating operation, allowing for the control of the heating element based on measured voltage differences to determine if the protrusions are damaged, thereby preventing the use of damaged ejection ports and maintaining print quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a protrusion is provided at the ejection port to prevent satellite droplet generation, then recording quality is improved, but the protrusion may be damaged by external stress and become undetectable
Solution Approach 1:
The patent implements a feedback mechanism by measuring the temperature distribution around the ejection port using a temperature distribution measurement element. When the protrusion is damaged, the temperature distribution changes, providing feedback that indicates damage. This allows the system to detect protrusion damage and respond by stopping ejection from affected ports, thereby maintaining recording quality despite the potential for undetected damage.
Solution Approach 2:
The patent replaces direct mechanical inspection of the protrusion with a thermal field-based detection method. Instead of mechanically checking the protrusion structure, the system uses temperature distribution measurement to indirectly detect protrusion integrity. This substitution allows for non-contact, continuous monitoring of protrusion condition without adding mechanical complexity to the ejection port structure.
2Productivity
If the protrusion is damaged and undetected, then recording quality deteriorates due to satellite droplet generation, but continuous operation is maintained
Solution Approach 1:
The temperature distribution measurement provides continuous feedback on the condition of each ejection port. When damage is detected through temperature distribution changes, the system immediately responds by stopping ejection from the affected port, preventing further quality deterioration while maintaining operation of other ports.
Solution Approach 2:
When protrusion damage is detected, the system discards the functionality of the damaged ejection port by stopping its operation. This allows the remaining healthy ports to continue recording, effectively recovering partial productivity while preventing quality issues from the damaged port. The system can later recover full capacity by replacing or repairing the damaged head.
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 solution effectively prevents the deterioration of recording quality by identifying and addressing damaged protrusions, ensuring continuous high-quality printing by controlling the heating element and utilizing adjacent ejection ports when necessary.
Implementation Method 1
a first substrate including a heating element configured to heat the liquid to eject the liquid from the ejection port
Implementation Method 2
a temperature detection element configured to detect temperature of the first substrate, wherein driving of the heating element is controlled based on whether a difference between a voltage value Vp1 measured by the temperature detection element and a preset voltage value Vp01 has a positive value within or outside a predetermined range
Data Source
AI summary
A recording apparatus includes a liquid ejection head, where the liquid ejection head includes: an ejection port, a first substrate, and a temperature detection element. The ejection port ejects liquid and includes a protrusion extending toward an ejection port inside. The first substrate includes a heating element that ejects liquid from the ejection port using heat. The temperature detection element detects temperature of the first substrate. Driving of the heating element is controlled based on whether a difference between a voltage value Vp1 measured by the temperature detection element and a preset voltage value Vp01 has a positive value within or outside a predetermined range or a negative value outside the predetermined range. The voltage value Vp1 is measured when a temperature change amount becomes maximum in a temperature falling process of a second substrate located, after the heating element is driven, at a position corresponding to the heating element.