Laser Machining Optical Scanner with Spherical Mirror
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laser machining devices face challenges in maintaining constant laser beam speed and focused state during scanning, leading to uneven machining and operational reliability issues, particularly when scaling up the optical scanning device for wider scanning ranges.
Innovation Solution
The implementation of a light projector with a rotating multifaceted mirror and a light reflector that includes multiple reflecting surfaces, allowing the laser beam to maintain constant speed and focus across the scanning line, along with a cylindrical lens to flatten the pulse laser beam, enables efficient and precise machining.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a constant-speed deflector is used to scan the laser beam, then the operational reliability is improved, but the scanning speed varies between the ends and middle of the scanning line causing uneven machining
Solution Approach 1:
The patent applies a spherical mirror instead of a flat mirror in the optical scanning device. The spherical mirror's curved surface compensates for the varying optical path lengths from the deflector to different positions on the scanning line, ensuring that the laser beam travels equal distances to all points on the scanning line. This eliminates the scanning speed variation caused by constant-speed deflection, achieving uniform machining while maintaining operational reliability through constant deflector speed.
2Manufacturing precision
If an fθ lens is used to eliminate scanning speed difference, then the machining uniformity is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent extracts and eliminates the fθ lens from the optical scanning system, replacing it with a spherical mirror. This removes the need for complex, highly technical fθ lens design and manufacturing, while still achieving the desired uniform scanning speed and machining quality through the spherical mirror's geometric properties.
Solution Approach 2:
The patent replaces the optical correction approach (using an fθ lens to correct scanning speed variation) with a geometric approach (using a spherical mirror to equalize optical path lengths). This substitution simplifies the optical system by eliminating the need for specialized lens design and manufacturing.
3Area of stationary object
If the size of the optical scanning device is increased for wider scanning range, then the scanning range is improved, but the difficulty of production and scaling increases
Solution Approach 1:
The patent segments the optical scanning system into modular components: a standard deflector, a spherical mirror, and a laser source. This modular design allows the system to be scaled for wider scanning ranges by adjusting the spherical mirror's size or position without requiring complex redesign, improving ease of manufacture and scalability.
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 configuration ensures constant-speed laser beam scanning, reduces machining time, and improves production efficiency by maintaining focus and precision, even when scaling up the device for larger scanning ranges.
Implementation Method 1
a light projector 65 and a light reflector 66. The light projector 65 radiates the laser beam 50 in a manner to cause the laser beam 50 to make angular movement. The light reflector 66 reflects the laser beam 50 radiated from the light projector 65
Implementation Method 2
a cylindrical lens 67. The cylindrical lens 67 flattens the pulse laser beam 51
Implementation Method 3
The light reflector 66 reflects the laser beam 50 radiated from the light projector 65. The plurality of mirrors 73, 74 which serve as the light reflector 66
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An optical scanning device (32) includes: a light projector (65) configured to radiate light while causing the light to make angular movement at a constant speed; and a light reflector (66) configured to reflect the light radiated from the light projector (65) to guide the light to an intended irradiated point on a predetermined scanning line (52). The light reflector (66) includes a plurality of reflecting portions (71, 72) and reflects, at least twice, the light radiated from the light projector (56) to guide the light to the intended irradiated point. The reflecting portions (71, 72) each include a plurality of reflecting surfaces (77, 78). A length of an optical path from the light projector (65) to the irradiated point is substantially constant for all of irradiated points on the scanning line (52), and a scanning speed, on the scanning line (52), of the light radiated from the light projector (65) is substantially constant.