Print Head Temperature Control via Dot Count and Sensor Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ink jet printing apparatuses face issues with abnormal temperature rises during vacant ejection operations, leading to potential damage and reduced throughput due to inadequate temperature detection and ink supply system inefficiencies, particularly in thermal and tube supply systems.
Innovation Solution
A printing apparatus with temperature detection sensors at both ends of the print head, an acquisition unit to track the number of dots to be printed, and a control unit that adjusts printing modes based on temperature and dot count, reducing the number of dots printed per unit time during vacant ejection to prevent overheating, while maintaining throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the temperature threshold value is set low to prevent abnormal temperature rise at vacant ejection position, then the print head is protected from damage, but the printing operation is limited frequently even in normal state, resulting in reduction of throughput
Solution Approach 1:
The print head is divided into multiple heating element regions (first heating element region and second heating element region) with temperature detection elements positioned at different locations. This segmentation allows independent temperature monitoring and control for different regions, enabling the system to distinguish between localized vacant ejection heating and overall print head temperature rise, thereby avoiding unnecessary throughput reduction while protecting against damage.
Solution Approach 2:
The control unit performs preliminary judgment about the presence of ink in the print head by analyzing the temperature detection results before allowing printing operations to proceed. This preliminary action enables the system to prevent damage by detecting vacant ejection conditions in advance, while also avoiding unnecessary interruptions to normal printing operations.
2Device complexity
If the temperature detection element is positioned at both ends of the substrate apart from the vacant ejection portion, then the temperature detection is simplified, but the heat conduction delay causes deviation between detected temperature and actual temperature at vacant ejection position
Solution Approach 1:
Instead of relying solely on temperature detection at the substrate ends, the system uses the spatial distribution of multiple temperature detection elements positioned at different locations (including near the heating element regions) to infer the temperature state at the vacant ejection position. This dimensional approach to temperature monitoring improves measurement accuracy without requiring direct contact with the hottest region.
Solution Approach 2:
The control unit continuously monitors temperature detection results from multiple elements and uses this feedback to judge the presence of ink and control printing operations. The feedback mechanism allows the system to compensate for heat conduction delays by analyzing temperature trends and patterns across different detection points, thereby improving temperature measurement accuracy.
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
Effectively prevents print head damage from abnormal temperature rises and minimizes throughput reduction by dynamically adjusting printing operations based on real-time temperature and dot count data, regardless of ink remaining amount in the tank.
Implementation Method 1
ink is ejected from the print head by making use of thermal energy generated from the heating element, such as a heater
Implementation Method 2
the temperature detection unit is provided at both ends of the substrate of the print head
Data Source
AI summary
One embodiment of the present invention is a printing apparatus including: a print head having a printing element column in which a plurality of printing elements for ejecting ink from ejection ports is arrayed and performing printing on a printing medium by ejecting ink based on print data; a sensor that detects temperature of the print head; an acquisition unit configured to acquire information indicating a number of dots to be printed by printing elements corresponding to a predetermined area in the printing element column; and a control unit configured to control a printing operation of the print head based on temperature detected by the sensor and the number of dots acquired by the acquisition unit, and the printing apparatus performs printing on the printing medium by ejecting ink from the print head while the print head and the printing medium are moving relatively.