Real-time laser focusing system for high-precision micromachining using diffractive beam sampler and advanced image sensor

Laser engraving of photographs on wood surfaces is a challenging task. To optimize the outcome and production quality it is necessary to control every aspect of the laser engraving process. Most of the production machines and technologies overall are mainly focused on laser power control. However, with other systems and deeper knowledge of the wood characteristics it is possible to achieve even better quality. This paper deals with enlarging the number of achievable shades of burned wood and its optimization. A calibration system was developed to control colour shades of engraved wood with a combination of laser power and optic focus. With this approach it is possible to widen achievable palette of engraved shades by continuous control of chemical processes of laser and wood interaction. The production is divided into wood burning and wood carbonization by variation of laser beam focus.

show abstract

“…The upper half of the shades will then be obtained with a defocused beam. Similar systems are already used as autofocus systems (Cao et al 2018).…”

Section: Shade Samplementioning

confidence: 99%

Laser beam calibration for wood surface colour treatment

Jurek

Wagnerova

2021

Eur. J. Wood Prod.

View full text Add to dashboard Cite

show abstract

“…The laser interacts differently with different wood species and grain orientations, resulting in varying engraving depths, colour changes, and contrasts. These heterogeneities can signi cantly degrade achieved results in terms of users perception (Cao, et al, 2018) (Diaci, Bračun, Gorkič, & Možina, 2011). Furthermore, the density and hardness of wood can signi cantly impact the laser engraving process.…”

Section: Introductionmentioning

confidence: 99%

Crafting Pixels in Wood: Understanding the Interplay of Technologies and Visual Perception in Wooden Photo Engraving

Jurek,

Wagnerová,

Šafář

2024

Preprint

View full text Add to dashboard Cite

This paper delves into the realm of laser engraving of photographs on wooden surfaces and explores the differences between mathematical and human perception. Wide quality study was used to, thoroughly explore the results attainable by 27 different realisations. The evaluation process involves both objective analyses and subjective assessments from hundreds of ratings of 60 evaluators, aiming to unravel the intricate interplay between technologies and visual perception. The study also poses the intriguing question of whether the image most accurately transferred onto a wooden surface is also the most favourably perceived by potential users.

show abstract

“…The accuracy of spot location plays a crucial role in the overall performance of methods such as centroid extraction [4] and motion parameter measurement [5]. Auto-focusing methods based on the relationship between defocusing displacement and the distance of two spots in optical systems have been proposed by Cao et al [6], [7]. However, these methods are limited in detecting the distance between two laser beams when they overlap.…”

Section: Introductionmentioning

confidence: 99%

Accurate subpixel center determination for overlapping spots

Tao,

Nguyen,

Nguyen

et al. 2024

Preprint

View full text Add to dashboard Cite

Precisely detecting laser beam locations is crucial in maximizing the performance of optical systems in manufacturing and measurement applications. There are numerous methods dealing with a single spot, but identifying overlapping spot centers is still challenging. To address this issue, we present an innovative approach that uses convolutional neural networks and image processing techniques to localize overlapping spot centers. Our method begins by utilizing the convolutional neural network to extract two crucial features: the ratio of minor to major axes and the orientation of the spots. Then, the Euclidean distance transform is employed to identify the approximate centers of the spots, which are the positions with the highest intensity in the transformed images. Finally, the gradient descent algorithm is applied to determine the precise center locations. In addition, noise was added to examine the ability to work in actual systems. The results indicate that our method performs well in noisy environments, accurately pinpointing overlapping spot centers in real-time with a 92% success rate. Furthermore, our approach strikes an excellent balance between accuracy and computational efficiency, making it suitable for use in actual laser manufacturing systems.

show abstract

Real-time laser focusing system for high-precision micromachining using diffractive beam sampler and advanced image sensor

Cited by 18 publications

References 26 publications

Laser beam calibration for wood surface colour treatment

Laser beam calibration for wood surface colour treatment

Crafting Pixels in Wood: Understanding the Interplay of Technologies and Visual Perception in Wooden Photo Engraving

Accurate subpixel center determination for overlapping spots

Contact Info

Product

Resources

About