Dynamic Printhead Positioning for Skewed Object Printing
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Solution Overview
Problem
Industrial printing devices face challenges in aligning and printing on skewed objects moving on conveyors, as existing solutions are either bulky, complex, or fail to accurately position printheads within a predefined print zone, leading to inefficient image printing.
Innovation Solution
A dynamic positioning system using sensors and a controller to detect object skew and adjust the printhead's orientation in real-time, ensuring accurate printing within the predefined print zone by calculating the object's skew and compensating for its orientation relative to the direction of travel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If contact-based printing apparatuses are used to print on moving objects, then printing can be performed on objects, but the apparatuses become bulky and complex and can damage the passing objects
Solution Approach 1:
The patent replaces contact-based mechanical printing systems with a non-contact imaging system that uses sensors to detect object skew and a controller to calculate positioning adjustments. The printhead positions are dynamically adjusted based on calculated skew angles without physical contact with the moving objects, eliminating the need for bulky mechanical contact structures.
Solution Approach 2:
The patent introduces sensors as intermediary devices that detect object characteristics (skew, position) without contact, and uses a controller as an intermediary to process this information and calculate the necessary positioning adjustments. This intermediary detection and calculation system replaces direct mechanical contact between the printing apparatus and moving objects.
2Manufacturing precision
If guide rails are used to deskew objects prior to printing, then object alignment is improved, but the apparatus becomes problematic for objects with slight variations in dimensions or different sizes
Solution Approach 1:
The patent implements a dynamic positioning system where the printhead positions are continuously adjusted based on real-time sensor detection of object skew. Rather than using fixed guide rails, the system dynamically calculates and applies positioning corrections for each object based on its actual skew angle, allowing adaptation to objects of varying sizes and dimensions.
Solution Approach 2:
The patent changes the approach from mechanically constraining objects to changing the positioning parameters of the printhead based on detected object characteristics. The controller calculates adjusted printhead positions as a function of detected skew angles, allowing the system to adapt to different object dimensions and skew variations without physical constraints.
3Reliability
If spring-biasing systems are used to keep the printhead in contact with moving objects, then the printhead remains close to the object, but the apparatus becomes bulky and complex and can damage the passing objects
Solution Approach 1:
The patent replaces spring-biasing mechanical contact systems with a non-contact sensing and calculation system. Sensors detect object position and skew without contact, and the controller calculates the appropriate printhead positioning to maintain optimal printing distance without requiring mechanical biasing forces or physical contact structures.
4Manufacturing precision
If dynamic positioning of the printhead is implemented to compensate for object skew, then printing accuracy on skewed objects is improved, but the device complexity increases due to sensors and control mechanisms
Solution Approach 1:
The patent implements a feedback system where sensors continuously detect object skew and position, the controller calculates the necessary positioning adjustments based on this feedback, and the printhead positioning is dynamically adjusted accordingly. This closed-loop feedback mechanism enables high printing accuracy while using relatively simple sensor and calculation components.
Solution Approach 2:
The system uses the objects themselves as the reference for positioning - the sensors detect features on each object, and the controller calculates positioning adjustments specific to that object's skew and position. Each object essentially serves its own positioning reference function, eliminating the need for complex external positioning infrastructure.
Data Source
AI summary
A printing apparatus for printing within a predefined print zone on a selected surface of a skewed object moving in a given direction of travel includes a bracket, at least two sensors at known positions adjacent to the passing object detecting the leading edge of a given surface, a positioning mechanism mounted on the bracket, a printhead mounted on the positioning mechanism and operable to print on the moving object selected surface, the positioning mechanism operable to position the printhead into a known correct printing position relative to the selected surface, and a controller communicating with the sensors, positioning mechanism, and printhead, and operable to calculate object skew in response to the sensor signals and to operate the positioning mechanism to position the printhead into the known correct printing position and to operate the printhead to print within the predefined print zone on the skewed moving object.