Piezoelectric Detection Unit for Foreign Object Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid ejecting apparatuses face challenges in accurately detecting foreign objects on the medium surface or medium curvature without damaging the apparatus, as they require complex optical axis adjustments and electrical control devices.
Innovation Solution
A liquid ejecting apparatus equipped with a detection unit featuring a piezoelectric film sensor and cantilevered plate portions that can detect foreign objects or medium curvature with high sensitivity, allowing for precise detection without the need for special device adjustments or electrical controls, and reducing the risk of damage to the apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an optical detection device is used to detect foreign objects with high accuracy, then detection precision is improved, but device complexity increases due to required optical axis adjustment and electrical control devices
Solution Approach 1:
The patent replaces the optical detection device with a mechanical detection unit consisting of a plate structure that directly contacts foreign objects. This mechanical system eliminates the need for complex optical axis adjustment and electrical control devices while maintaining high detection accuracy through direct physical contact between the plate and foreign objects on the medium surface
Solution Approach 2:
The detection unit uses a simple plate structure that can be easily manufactured and replaced if needed, substituting expensive and complex optical systems with a more economical mechanical solution that achieves the same detection function through straightforward contact mechanics
2Ease of operation
If a detection unit with plate portions is used to simplify equipment adjustment, then ease of operation is improved, but detection precision may be reduced compared to optical devices
Solution Approach 1:
The plate portions are designed with specific geometric features including bent sections and gaps that allow them to flexibly contact foreign objects while maintaining structural integrity. The thin plate structure can deform to conform to the medium surface and foreign object shapes, ensuring reliable contact-based detection without requiring complex adjustment mechanisms
Solution Approach 2:
The detection plate is divided into multiple portions (first plate portion, second plate portion, third plate portion) with distinct functions. The second plate portion contacts the medium surface for detection, while the third plate portion with a gap provides additional detection capability and structural support, allowing each segment to be optimized for its specific function while simplifying overall adjustment
3Reliability
If the detection unit is positioned on the upstream side of the liquid ejecting unit, then the liquid ejecting unit is protected from damage, but the detection unit may come into contact with the medium more frequently
Solution Approach 1:
The detection unit is positioned upstream of the liquid ejecting unit to perform preliminary detection of foreign objects on the medium surface before the medium reaches the liquid ejecting unit. This early detection allows the system to take preventive action (such as stopping medium transport or alerting the operator) before foreign objects can cause damage to the liquid ejecting unit, thus protecting the expensive component while accepting controlled contact with the medium during normal operation
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 solution enables high-accuracy foreign object detection, simplifies mechanical adjustments, and reduces the risk of damage to the apparatus by detecting foreign objects or medium curvature before they reach the liquid ejecting unit, thereby enhancing the apparatus's reliability and durability.
Implementation Method 1
a piezoelectric film sensor that is provided in the detection unit and outputs an electric signal when the object comes into contact with the detection unit
Data Source
AI summary
A detection unit that detects the presence of an object that can come into contact with a liquid ejecting unit with relative movement between a medium and the liquid ejecting unit is provided with a piezoelectric film sensor that outputs an electrical signal when the object comes into contact with the detection unit, where the detection unit has first, second, and third plate portions formed so as to be continuous, the first plate portion is fixed so that the second and third plate portions are cantilevered, and the second plate portion, in a state where the piezoelectric film sensor is mounted thereon, is continuous with the first plate portion and is disposed diagonally with respect to the vertical direction of the medium, and the third plate portion is bent from the second plate portion and faces the medium leaving a gap between the third plate portion and the medium.