Ink Jet Head Contact Force Detection Using Encoder Displacement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing printing apparatuses face issues with detecting contact forces between the ink jet head and various types of printing media, leading to unnecessary downtime due to over-sensitivity or potential damage from under-sensitivity, as they cannot accurately differentiate between different rigidity levels of media.
Innovation Solution
A printing apparatus with a displacement section and encoder system that measures contact forces and controls movement based on detected displacement, allowing for adaptive printing sequences and reduced downtime by distinguishing between different contact states and media types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If contact detection sensitivity is increased to prevent ink jet head damage, then reliability improves, but unnecessary downtime increases due to false alarms on low-rigidity media
Solution Approach 1:
The patent changes the detection parameter from binary contact detection to quantitative contact force measurement. By measuring the magnitude of contact force rather than simply detecting presence/absence of contact, the system can distinguish between harmful contact (high force) and acceptable contact (low force), resolving the contradiction between reliability and downtime
Solution Approach 2:
The patent replaces the mechanical photo interrupter sensor with a force measurement mechanism that directly quantifies contact force. This substitution enables precise measurement of contact magnitude rather than indirect detection, allowing the system to differentiate between harmful and harmless contact scenarios
2Productivity
If contact detection sensitivity is decreased to reduce downtime, then productivity improves, but the risk of ink jet head damage increases
Solution Approach 1:
The system changes from insensitive binary detection to sensitive quantitative measurement. By measuring contact force magnitude, the system can identify dangerous contact levels that would be missed by low-sensitivity binary sensors, thus protecting the ink jet head while maintaining productivity
Solution Approach 2:
The patent implements feedback control based on measured contact force. The control section continuously monitors contact force magnitude and adjusts printing operations accordingly, stopping only when force exceeds safe thresholds. This feedback mechanism ensures both productivity and equipment protection
3Device complexity
If binary contact detection is used to simplify the system, then device complexity decreases, but measurement precision deteriorates
Solution Approach 1:
The patent replaces complex binary sensors with a force measurement mechanism that provides quantitative data. Although the force measurement mechanism adds some complexity, it eliminates the need for multiple binary sensors and complex control logic, achieving better measurement precision with comparable overall system complexity
Solution Approach 2:
The force measurement mechanism serves multiple functions: it detects contact presence, measures contact magnitude, and provides data for control decisions. This multi-functionality replaces what would otherwise require multiple separate detection systems, maintaining simplicity while improving precision
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
The system effectively prevents unnecessary downtime and damage by accurately detecting contact forces and adjusting printing sequences, ensuring optimal operation across various media types and reducing mechanical stress on the ink jet head.
Implementation Method 1
an encoder that measures a displacement amount of the displacement section and outputs an output value corresponding to the displacement amount
Data Source
AI summary
A printing apparatus includes an ejecting head that ejects ink droplets onto a surface of a printing medium (paper roll), a carriage on which the ejecting head is mounted, a platen that faces the ejecting head and supports the printing medium, a detector plate provided in the carriage and is displaced in accordance with an external force applied in response to contact with the printing medium, and an encoder that measures a displacement amount of the detector plate and outputs an output value corresponding to the displacement amount.