Laser Processing Head Diaphragm to Expand Scan Field
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Laser processing heads face limitations in scan field due to beam deflection angles causing vignetting and thermal focus shifts, leading to power losses and potential lens damage, which restricts the maximum usable scan field, especially at high laser powers.
Innovation Solution
Incorporating a diaphragm within the laser processing head to reduce the laser beam's diameter by cutting its peripheral portion, allowing only the more intense central portion to pass through, thus preventing beam edges from hitting optical element edges and allowing for a larger scan field without increasing power density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the deflection angle is increased to achieve a larger scan field, then the scan field size is improved, but vignetting occurs at optical element edges causing power loss and thermal focus shift
Solution Approach 1:
The patent applies preliminary action by pre-defining a safe scan field boundary that is smaller than the maximum physical boundary of the optical elements. The control unit restricts the laser beam deflection to angles that keep the beam entirely within the active optical surface area, preventing vignetting before it occurs. This proactive approach ensures the beam never reaches the edges where power loss and thermal effects would begin.
Solution Approach 2:
The patent changes the operational parameters by dynamically adjusting the maximum allowable deflection angle based on the optical element's characteristics. Instead of using the maximum physical deflection capability, the system operates at optimized deflection angles that maintain the beam within the safe zone, thereby eliminating vignetting-related power loss while still achieving a functional scan field.
2Area of stationary object
If the deflection angle is increased to achieve a larger scan field, then the scan field size is improved, but thermal focus shift occurs leading to potential lens damage
Solution Approach 1:
The patent applies preliminary action by pre-establishing safe operational boundaries that prevent the laser beam from reaching optical element edges. The control unit is programmed with knowledge of the optical elements' thermal characteristics and restricts deflection angles accordingly, preventing thermal focus shift and potential lens damage before they can occur.
Solution Approach 2:
The patent implements beforehand cushioning by creating a protective margin between the laser beam path and the optical element edges. This safety buffer zone ensures that even at maximum operational deflection angles, the beam remains well within the safe area, providing a cushion against thermal effects that could lead to focus shift or lens damage.
3Ease of operation
If the scan field is limited to a rectangular or square shape for ease of operation, then the ease of operation is improved, but the usable scan field area is further reduced
Solution Approach 1:
The patent applies asymmetry by allowing the scan field boundary to follow the natural circular or elliptical shape determined by the optical element geometry rather than forcing a rectangular shape. The control unit can define the scan field as a circle or ellipse that maximizes the usable area while still providing simple, programmable boundaries for operational ease.
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 solution increases the scan field by reducing the beam's diameter with a diaphragm, preventing vignetting and thermal issues, while maintaining sufficient intensity for processing, thereby expanding the usable scan area without lens damage.
Implementation Method 1
The diaphragm is configured to limit a diameter or cross-sectional area of the laser beam passing therethrough
Implementation Method 2
a collimating module configured to collimate the laser beam
Implementation Method 3
a focusing module configured to focus the laser beam
Implementation Method 4
a scanning module configured to deflect the laser beam
Data Source
AI summary
A laser processing head is presented. The laser processing head includes a laser entry module for introducing a laser beam; a collimating module for collimating the laser beam; a scanning module for deflecting the laser beam; a focusing module for focusing the laser beam; and at least one diaphragm for increasing a scan field of the laser beam. The diaphragm comprises a diaphragm body and an opening, and is configured to limit a cross-sectional area of the laser beam by the diaphragm body. The at least one diaphragm is positioned optically downstream of the laser entry module and optically upstream of the focusing module. A laser processing system including the laser processing head is also presented. Furthermore, a method for increasing a scan field of the laser beam is also provided.