Laser Plotter Auto-Focusing for Uneven Workpiece Engraving
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laser plotters face inaccuracies in focusing due to manual adjustments, require user input for material thickness, and are limited by light barriers, making it difficult to focus on uneven or thin workpieces effectively.
Innovation Solution
A method where the laser plotter performs a distance measurement on the workpiece surface after insertion, using an ultrasonic sensor to adjust the processing table for optimal focal point, allowing for precise focusing regardless of workpiece position or shape, and enabling the use of any lens without user corrections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If manual focusing is used to adjust the processing table height, then the focus position can be adjusted for different lenses, but the focusing accuracy is poor due to manual adjustment errors
Solution Approach 1:
The patent replaces the manual mechanical focusing system with an automated optical measurement system. A laser distance meter automatically measures the distance from the lens to the workpiece surface, eliminating manual height adjustment errors. The system calculates the required processing table height based on the measured distance and lens focal length, then automatically positions the table to achieve precise focus.
2Extent of automation
If automatic software focusing is used, then the focus position is calculated automatically, but the user must know and enter the exact material thickness and lens specifications
Solution Approach 1:
The system performs self-measurement using a laser distance meter to automatically determine the distance to the workpiece surface. This eliminates the need for users to manually input material thickness and lens specifications. The system autonomously gathers the necessary data through optical measurement and performs the focus calculation automatically.
3Extent of automation
If a light barrier is used for automatic focusing, then the focus can be adjusted automatically at a fixed position, but focusing is limited to a specific point and cannot handle thin or uneven workpieces
Solution Approach 1:
The patent transitions from a fixed-point light barrier measurement (2D plane constraint) to a laser distance meter that can measure along the optical axis (adding depth dimension). This allows the system to measure distances to workpieces at any position and orientation, including thin and uneven surfaces, by measuring the distance from the lens to the actual workpiece surface along the laser beam path.
4Adaptability or versatility
If the processing table is manually adjusted for focus, then different focal lengths can be accommodated, but the quality of engraving is impaired due to imprecise positioning
Solution Approach 1:
The system uses a laser distance meter to provide real-time feedback on the actual distance from the lens to the workpiece surface. Based on this feedback, the control unit calculates the precise processing table height required to achieve the correct focal position, and automatically adjusts the table to this position. This closed-loop feedback system ensures accurate focus positioning regardless of the lens focal length.
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 method ensures straightforward and accurate focusing, improving laser quality by allowing workpieces of any size or shape to be processed with increased user-friendliness and adaptability to various materials, eliminating the need for precise positioning and manual corrections.
Implementation Method 1
a distance measurement is then performed on the surface of the workpiece
Implementation Method 2
the laser light is focused sharply with a focusing lens. Thus, in the focus of the laser beam an extremely high power density is produced
Data Source
AI summary
The invention relates to a method for engraving, marking and/or labelling a workpiece using a laser plotter, as well as a laser plotter in which at least one beam source in the form of a laser is provided in a housing of the laser plotter, into which the item to be machined is inserted. The workpiece is placed on a processing table, and a laser beam emitted by the beam source is sent via deflecting elements to at least one focusing unit, from which the laser beam is deflected in the direction of the workpiece and is focused for the processing. The control, in particular the position control of the laser beam to the workpiece, takes place via a software running on a control unit, so that the workpiece is processed line by line by movement of a sliding carriage. Preferably on an external component, in particular a computer or a control unit, a graphic and/or a text is created, which is transmitted to the control unit of the laser plotter, which performs a conversion of the transmitted data, in particular the graphic and/or the text, for controlling the individual elements of the laser plotter. A laser pointer of the laser is positioned on or in the area of the workpiece after insertion of the workpiece into the working area, whereupon after activation of the machining process or a focusing process preferably a position correction is performed. Subsequently, a distance measurement to a surface of the workpiece is performed, and the data acquired are transferred to the control unit, which then calculates a position of the working table for the optimum focal point of the laser, taking into account predetermined parameters, in particular the replaceable laser lens used, and subsequently the processing table is shifted.