Automatic Defect Detection Instrument for Spherical Surfaces of Optical Elements
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis manuscript proposes a scanning type defect detection instrument for spherical optical surface. The main feature of the instrument is the capability of detecting an aperture size up to 400mm. The minimum detectable defect are scratch line width down to 2mm and pitting diameter down to 4mm. The whole instrument has been well built and tested for the desired performance. The proposed instrument for sure is valuable in terms of practical application. However, the point of novelty or technical breakthrough is not quite clear, and the description of the work is lack of deep concept and technical detail. Some comments are given as follows for the authors’ reference.
1. In line 63-64 of the manuscript, it has been stated that “the key technology of the automatic large-aperture curved surface detection for micron-scale defects remains underdeveloped”. It is suggested to describe clearly what exactly the key technology is, and this key technology should be somehow related to the bottleneck for developing large aperture detection instrument. This will help to highlight the major contribution of the work. Certainly the technical detail for breaking the bottleneck should be well described.
2. Each part of the instrument has been described in the manuscript, but lack of technical detail and working concept. Taking the multi-angle-channel illumination system as an example. It has been stated in line 174-176, “In order to accurately capture the defect images with characters of different directions, sizes and shapes, especially for weak scratches, a multi-angle-channel illumination system is designed to enhance the contrast between defects and background”. However, how and why the illumination system is designed is fully missing. Some kind of scattering theory might be involved which is considered as the key part for an academic publication. The same issue for the other part of the instrument.
3. There are totally 5 degrees of freedom for the scanning system, 2 from microscopic imaging system and 3 from optical element platform. This degree of freedom is already sufficient for non-spherical surface detection. It is suggested to make some comments on what could be the issue to make non-spherical version of the instrument, because quite a portion of large aperture optical elements are aspherics.
Comments on the Quality of English Language
Some grammatical errors or typos scatter over the whole manuscript, which needs proof reading
Author Response
Comment 1: In line 63-64 of the manuscript, it has been stated that “the key technology of the automatic large-aperture curved surface detection for micron-scale defects remains underdeveloped”. It is suggested to describe clearly what exactly the key technology is, and this key technology should be somehow related to the bottleneck for developing large aperture detection instrument. This will help to highlight the major contribution of the work. Certainly the technical detail for breaking the bottleneck should be well described.
Response 1: Thank you for pointing this out. We agree with this comment. Therefore, we have added key technologies that need to be considered during instrument design and development. The updated equation can be found on page 2, paragraph 3, line 68-95. We also have incorporated additional results comparing our technique with competing methods into Section 7 of the manuscript. These new findings can be found in the updated version of Section 7, starting from page 11 to page 12, line 297-316.
Comment 2: Each part of the instrument has been described in the manuscript, but lack of technical detail and working concept. Taking the multi-angle-channel illumination system as an example. It has been stated in line 174-176, “In order to accurately capture the defect images with characters of different directions, sizes and shapes, especially for weak scratches, a multi-angle-channel illumination system is designed to enhance the contrast between defects and background”. However, how and why the illumination system is designed is fully missing. Some kind of scattering theory might be involved which is considered as the key part for an academic publication. The same issue for the other part of the instrument.
Response 2: Thank you for pointing this out. We agree with this comment. Therefore, we have added a description of principles of instrument design and light source design in section 2. The added content can be found on page 3, paragraph 2-4, line 104-122.
Comment 3: There are totally 5 degrees of freedom for the scanning system, 2 from microscopic imaging system and 3 from optical element platform. This degree of freedom is already sufficient for non-spherical surface detection. It is suggested to make some comments on what could be the issue to make non-spherical version of the instrument, because quite a portion of large aperture optical elements are aspherics.
Response 3: Thank you for pointing this out. We agree with this comment, and that's what we are preparing to do recently. Therefore, we have added an explanation in the section of the Conclusions. The added content can be found on page 12, paragraph 2, line 326-330.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe manuscript may be published after the following comments are resolved.
1) The reference number is too small to cover current trends in the discussed research areas.
2) Lines 38-39 “generally classified into two categories:”. The phase imaging inspection techniques [1-3] and aberration detection techniques [4-6] should be also mentioned in this context.
[1] https://doi.org/10.1088/2040-8978/14/6/065701
[2] https://doi.org/10.1016/j.optlastec.2018.10.024
[3] https://doi.org/10.37188/lam.2022.017
[4] https://doi.org/10.18287/2412-6179-CO-906
[5] https://doi.org/10.1007/s00340-022-07778-y
[6] https://www.mdpi.com/2076-3417/13/8/4831
3) The detailed comparison of advantages of the proposed technique should be included into the revised manuscript for publishing this work in "Photonics" journal.
Lines 63-64 “the automatic large aperture curved surface detection for micron-scale defects”.
The following works are missed:
[1] https://doi.org/10.1117/12.3006601 presents a multimodal imaging approach for detecting micro defects on the surface of large-aperture optical components.
[2] https://doi.org/10.3788/COL201513.041102 focuses on alignment methods for automatic evaluation of micron-scale surface defects on large-aperture fine optics
[3] https://doi.org/10.1016/j.optlastec.2022.109011 proposes a set of surface flaw detection algorithms based on machine learning, including object segmentation, flaw feature extraction, classification and size measurement, for efficient and precise detection of surface flaws on large-aperture optical components.
[4] https://doi.org/10.1016/j.optlaseng.2008.03.010 describes an automated defect detection system for coated plastic surfaces, which is applicable to highly reflective curved surfaces.
4) Eq. 1 using of the capital letter (“Sin”) should be avoided here.
5) Lines 130-153. All variables should be written with italic font.
6) Line 183. The title of the section 4.4. title should be moved on the next page
7) The text in Fig.5 contains misprints. E.g. "displayer" is should be replaced with "display" in Fig. 5
8) The text is not recognizable in Fig. 6
9) Section 5. Experiment. The inclusion of the results of the comparison with the competing technique is strongly recommended.
10) Line 199 “1.3μm”. The space is missed
11) Line 203. The caption for Fig. 7 is misleading. It is not an experiment itself. On the image we can see the image of the calibration board with some insets, which should also be described.
12) Line 213. The image in Fig. 8 have unacceptable low contrast.
13) In Fig. 9 the block-scheme is not in accordance with ISO-standard.
14) Line 229 “As shown in Figure10”. The space is missed.
15) Line 243 “(a)Optical”. The space is missed.
16) Figure 10. The scale bar is missed in these images on Fig. 10; the contrast of image (c) is low.
Comments on the Quality of English LanguageThere are typos in the text.
Author Response
Comment 1: The reference number is too small to cover current trends in the discussed research areas.
Response 1: Thank you for pointing this out. We agree with this comment. Therefore, we have added some references and give some descriptions. The added content can be found in page 2, paragraph 2, line 39 and page 3, paragraph 3, line 76-88. The added reference are listed at the part of References, which is from 7 to 12 and 20 to 25.
Comment 2: Lines 38-39 “generally classified into two categories:”. The phase imaging inspection techniques [1-3] and aberration detection techniques [4-6] should be also mentioned in this context.
[1] https://doi.org/10.1088/2040-8978/14/6/065701phase retrieval for optical inspection of technical components
[2] https://doi.org/10.1016/j.optlastec.2018.10.024
[3] https://doi.org/10.37188/lam.2022.017
[4] https://doi.org/10.18287/2412-6179-CO-906
[5] https://doi.org/10.1007/s00340-022-07778-y
[6] https://www.mdpi.com/2076-3417/13/8/4831
Response 2: Thank you for pointing this out. We agree with this comment. Therefore, we have added the phase imaging inspection techniques and aberration detection techniques in the context. The added content can be found on page 1, paragraph 2, line 40-47.
Comment 3: The detailed comparison of advantages of the proposed technique should be included into the revised manuscript for publishing this work in "Photonics" journal.
Lines 63-64 “the automatic large aperture curved surface detection for micron-scale defects”.
The following works are missed:
[1] https://doi.org/10.1117/12.3006601 presents a multimodal imaging approach for detecting micro defects on the surface of large-aperture optical components.
[2] https://doi.org/10.3788/COL201513.041102 focuses on alignment methods for automatic evaluation of micron-scale surface defects on large-aperture fine optics
[3] https://doi.org/10.1016/j.optlastec.2022.109011 proposes a set of surface flaw detection algorithms based on machine learning, including object segmentation, flaw feature extraction, classification and size measurement, for efficient and precise detection of surface flaws on large-aperture optical components.
[4] https://doi.org/10.1016/j.optlaseng.2008.03.010 describes an automated defect detection system for coated plastic surfaces, which is applicable to highly reflective curved surfaces.
Response 3: Thank you for pointing this out. We agree with this comment. Therefore, we have added some descriptions of the proposed works by other researchers in the context. A more detailed analysis is provided about the advantages and drawbacks of other researches. The added content can be found on page 2, paragraph 3, from line 68 to line 91.
Comment 4: Eq. 1 using of the capital letter (“Sin”) should be avoided here.
Response 4: Thank you for pointing this out. I/We agree with this comment. Therefore, We have corrected the use of capital letters in Eq. 1 to ensure consistency with standard notation. The updated equation can be found on page 4, in section 4.1.
Comment 5: Lines 130-153. All variables should be written with italic font.
Response 5: Thank you for your observation. We have formatted all variables in this paper, including lines 130-153, in italic font in accordance with the journal's style guidelines. This update is reflected throughout the specified section of the manuscript.
Comment 6: Line 183. The title of the section 4.4. title should be moved on the next page.
Response 6: We appreciate your feedback. To address this, we have adjusted the placement of section titles in this paper, and updated the order as section 5.4 on page 8 to ensure proper pagination.
Comment 7: The text in Fig.5 contains misprints. E.g. "displayer" is should be replaced with "display" in Fig. 5.
Response 7: Thank you for identifying this issue. We have made the necessary corrections to Fig. 5, including replacing "displayer" with "display" to rectify the typographical errors. The updated figure is now available as figure 6 in the revised manuscript.
Comment 8: The text is not recognizable in Fig. 6.
Response 8: Acknowledging your concern, we have taken steps to enhance the legibility of text in Fig. 6 for improved clarity. The revised version now is much better readability as per your suggestion, which is updated as figure 7 in the revised manuscript.
Comment 9: Section 5. Experiment. The inclusion of the results of the comparison with the competing technique is strongly recommended.
Response 9: Thank you for your valuable suggestion. We have incorporated additional results comparing our technique with competing methods into Section 7 of the manuscript. These new findings can be found in the updated version of Section 7, starting from page 11 to page 12, line 297-316.
Comment 10: Line 199 “1.3μm”. The space is missed.
Response 10: We appreciate your attention to detail. The spacing issue in "1.3μm" on line 199 has been corrected for accuracy. The updated formatting can be seen in the revised manuscript on last paragraph of page 8, line 248.
Comment 11: Line 203. The caption for Fig. 7 is misleading. It is not an experiment itself. On the image we can see the image of the calibration board with some insets, which should also be described.
Response 11: Thank you for pointing this out. We have revised the caption for Fig. 7 to accurately describe the content, which is reordered as Figure 8 in in the revised manuscript. This clarification can now be found on page 9, below Figure 8.
Comment 12: Line 213. The image in Fig. 8 have unacceptable low contrast.
Response 12: We have addressed the contrast issue with the image in Fig. 8 to enhance visibility. The improved version of Fig. 8 now can be viewed, which is reordered as Figure 9 in the revised manuscript on page 9 and page 10.
Comment 13: In Fig. 9 the block-scheme is not in accordance with ISO-standard.
Response 13: Thank you for bringing this to our attention. We have adjusted the block-scheme in Fig. 9 to conform to ISO standards as required. The updated version of Fig. 9 is now available, which is reordered as Figure 10 in the revised manuscript on page 10.
Comment 14: Line 229 “As shown in Figure10”. The space is missed.
Response 14: We have corrected the spacing issue in "Figure10" to ensure proper formatting. The revised text can be found on page 10, the last paragraph, line 280.
Comment 15: Line 243 “(a)Optical”. The space is missed.
Response 15: Thank you for noting this. The spacing issue in "(a)Optical" has been corrected for consistency. You can find the corrected format in the revised manuscript on page 11, line 295.
Comment 16: Figure 10. The scale bar is missed in these images on Fig. 10; the contrast of image (c) is low.
Response 16: We have added a scale bar in these images and improved the contrast of image (c) for clarity. The updated version can now be seen, which is reordered as Figure 11 in the revised manuscript on page 11.
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors have added substantial material to address the issues raised in the previous review. This manuscript proposes a scanning type defect detection instrument for large aperture spherical optical surface up to 400mm with the potential to be upgraded for checking aspherics. It can be considered for the publication in Photonics.
Comments on the Quality of English LanguageN/A
