Utilization of CD and DVD Pick-Up Heads for Scratch Inspection of Magnetic Disk in Dynamic State Using Microcontroller
Round 1
Reviewer 1 Report
Thank you for improving your manuscript. Unfortunaetly, the improvements made are too small from my point of view.
I cannot see any highlighted sections mentioned in the response letter. Also, the line numbers mentioned in the response do not seem to match the text.
- Still, it is not sufficiently addressed inhowfar scientific progress has been made. The state of the art contains much proof that optical, such as interferometriy-based, approaches are suitable. The cost question is not sufficiently illuminated.
- The answer to question 3 does not address the core of the question. There is no related improvement in the manuscript.
- The answer to question 4 does not address the core of the question. I cannot find the related explanation in line 108-111.
- The issue with the role of the oscilloscope is not resolved. There is no waveAce 2010 oscilloscope in the LeCroy program (at least as to LeCroy documentation of the 2000 series). The manufacturer LeCroy is not mentioned. The bandwith 40-300 GHz and 2 GSa/s is the maximum range of the 2000 series of LeCroy. What oscilloscope was really used?
- The answer to question 5 does not help. Maybe the question was not understood. It is clear that scanning is done in angle and radius direction, of course. Line 81-82 contain no information related to this. The question was about the detectability of shorter cracks and if those long cracks that were investigated are realistic.
- The explanation of the industrial need seems to indicate that 10+ µm cracks are relevant (line 60/61). However the approach seems to address only 55+ µm cracks. Why didn't the authors examine borderline scenarios? And why only three cracks? This is no sufficient examination of a probability of detection, and no comparision to the needs. I can only see that three long cracks of different width were detected.
- Regarding question 7, the authors do not want to improve the tiny text in the sub-graph. It is up to the editor if this is okay, but I personally think it is so easy to improve, so why not just do it? If the authors do not want the reader to see the text, then just show a curve.
- Regarding question 8, the answer "This error was acceptable by industry because it needs to know exactly that there is a scratch of a certain size on a disk" does not confirm that 25% are acceptable. It is rather a non-answer.
- Language and grammar issues remain unsolved. Although the authors mention proofreading by a Canadian, every second sentence contains mistakes or, at least, some space for improvement. The language errors in the answer "One of our staff in Physic Department, a Canadian, was reviewed prior to being submitted." is characteristic for the language in the paper.
Author Response
1. Still, it is not sufficiently addressed inhowfar scientific progress has been made. The state of the art contains much proof that optical, such as interferometriy-based, approaches are suitable. The cost question is not sufficiently illuminated.
Respond: We have explained in the revised paper that our aim of this work in to make an instrument that can inspect scratch on magnetic disk in terms of FAST and ALL inspection. We and industry do not aim to invent a state-of the art instrument! We have most state of the art instrument in industry but...the media disk has to randomly inspect.
2. The answer to question 3 does not address the core of the question. There is no related improvement in the manuscript.
Respond: We have already explained and add more explanation in line 60-68 that the state of the art instruments cannot inspect all media disk because it takes time. So, industry need a handy instrument to inspect big scratch of ALL media disk in a rapid time. So, I ask the reviewer to read and understand our aims of work thoroughly.
3. The answer to question 4 does not address the core of the question. I cannot find the related explanation in line 108-111.
Respond: In the last suggestion, the reviewer commented that "Is the microcontroller only used for controlling the HDD motor and focusing? This is not
well described." .....I have answered that it is true that the microcontroller is used to control the HDD motor. This has been described in lines 110-113. The reviewer please kindly read and understand that our style of writing may not be the same as yours. We are very sure that the readers can understand this as shown in line 110-113.
4. The issue with the role of the oscilloscope is not resolved. There is no waveAce 2010 oscilloscope in the LeCroy program (at least as to LeCroy documentation of the 2000 series). The manufacturer LeCroy is not mentioned. The bandwith 40-300 GHz and 2 GSa/s is the maximum range of the 2000 series of LeCroy. What oscilloscope was really used?
Respond: "WaveACE 2010" means the product's family. There are 2 products in this family: waveAce 2012 and waveAce 2014". Since this research has not been funded by LeCroy and we do not need to advertise LeCroy! I am sure that all electronic engineers in this world definitely know this.
The reviewer suggested that we should show LeCroy waveAce 2000 series. In fact there is no waveAce 2000 in market but there are waveAce 2002 and waveAce 2004... I hope this respond may be useful for reviewer.
However, We can tell you that we use Lecroy waveAce 2012. (waveAce xxx2 means that there are 2 channels and waveAce xxx4 means that there are 4 channels).
5. The answer to question 5 does not help. Maybe the question was not understood. It is clear that scanning is done in angle and radius direction, of course. Line 81-82 contain no information related to this. The question was about the detectability of shorter cracks and if those long cracks that were investigated are realistic.
Respond: Either it is long in radius or circular direction, the scratch can be inspected because there are 4 quadrant sensors in a photodiode detector and we have 4 phodiode detectors on pick-up head. So it can detect long or short scratches but not smaller than 10+ micrometer scale.
6. The explanation of the industrial need seems to indicate that 10+ µm cracks are relevant (line 60/61). However the approach seems to address only 55+ µm cracks. Why didn't the authors examine borderline scenarios? And why only three cracks? This is no sufficient examination of a probability of detection, and no comparision to the needs. I can only see that three long cracks of different width were detected.
Respond: We can change from "10+ µm scale" to "50+ µm scale" if the reviewer and editor suggest. But typically in scientific publication or normal standard if we will show the scale's range, we will write as "+10 m scale, +100 m scale or songs in 80s, 90s". We will not write "+15 m scale or song in 95s".
We use 3 sizes of low borderline, middle and high borderline of requirement. We think this is enough to cover all size in this range. The range of measuring ability is calculated from the wavelength of CD/DVD. These have been explained in the paper already.
7. Regarding question 7, the authors do not want to improve the tiny text in the sub-graph. It is up to the editor if this is okay, but I personally think it is so easy to improve, so why not just do it? If the authors do not want the reader to see the text, then just show a curve.
Respond: The details of sub-graph have been shown in Table 3. We have already explained that the sub-graph in Figure 7 aims to show the shape only !!
If we put the same figure in both Figure 7 and Table 3, I think it is duplicate!!! No researchers do this.
8. Regarding question 8, the answer "This error was acceptable by industry because it needs to know exactly that there is a scratch of a certain size on a disk" does not confirm that 25% are acceptable. It is rather a non-answer.
Respond: One of our author(Dr. Warunee Tupchareon) is a senior staff in Seagate. This confirms that the results of 25% accepability is an answer. The reviewer must know that industrial confident is very much important.
9. Language and grammar issues remain unsolved. Although the authors mention proofreading by a Canadian, every second sentence contains mistakes or, at least, some space for improvement. The language errors in the answer "One of our staff in Physic Department, a Canadian, was reviewed prior to being submitted." is characteristic for the language in the paper.
Respond: If the editor think it need English editing, we are more than happy to do so.
Reviewer 2 Report
The authors demonstrated an optical positioning system to measure scratches on magnetic disks. The system is based on a CD or DVD pick up head. With quadrant photodetectors, the scratches are measured based on position change of the reflected beam. The method, system, and measurement are well detailed. I think this manuscript meets the journal requirement and can be considered for publication. Here I have a few questions and comments.
1. In figure 5, a set of four quadrant photo sensors and a set of photodiode detectors are shown. Can the authors explain what is the difference between four quadrant photo sensors and photodiode detectors?
2. The captions of figure 7 and 8 are the same.
3. In table 2, I recommend that the authors should be careful about the significant figures of the number.
4. What is the measurement uncertainty or reputability? Or what is the standard deviation of a few repetitive measurements.
5. I think the title is a bit miss leading. “2 Wavelength Effects” let me think about a spectral laser ranging method based on two wavelength or systematics due to wavelength. But it turned out the the two wavelength measured similar results. So, I recommend the authors should think about revising the title.
Author Response
1. In figure 5, a set of four quadrant photo sensors and a set of photodiode detectors are shown. Can the authors explain what is the difference between four quadrant photo sensors and photodiode detectors?
Respond: A photodiode detector comprises 4 photo sensors. This is shown in figure 2. Hoever, I have added an explanation for more understanding in line 86 from " four quadrant sensors of photodiode detector" to " 4 quadrant sensors of a photodiode detector".
2. The captions of figure 7 and 8 are the same
Respond: We have change Figure 8's caption from "by CD" to "by DVD".
3.In table 2, I recommend that the authors should be careful about the significant figures of the number.
Respond: We have changed the bold fonts to regular fonts.
4.What is the measurement uncertainty or reputability? Or what is the standard deviation of a few repetitive measurements
Respond: The aim of this research is to be able to identify big size scratches in a quick time and low-cost. However, in Table 2, we showed that this invented instrument can not only identify a scratch but also provide less error than conventional SM. In addition, a media disk must be cut and destroy for measurement by SM that is time consumed and random process. This proposed instrument can inspect all magnetic disks.
5. I think the title is a bit miss leading. “2 Wavelength Effects” let me think about a spectral laser ranging method based on two wavelength or systematics due to wavelength. But it turned out the the two wavelength measured similar results. So, I recommend the authors should think about revising the title.
Respond: I have changed the title from "Comparison Study of 2 Wavelength Effects .." to " Utilization of CD and DVD Pick-Up Heads...."
Thank you very much in deed for all constructive comments.
Reviewer 3 Report
The article shows only a very specific application of the well-known measuring technique. I have doubts whether the article should be published as a scientific article or as a technical report
Detailed comment:
- The left side of equations 2 and 3 cannot be denoted in the same way.
Similarly the left side of equations 4 and 5 cannot be denoted in the same way.
- The description set out in point 2.2. has been known for nearly 40 years! and it was presented in many articles. A description of different versions of DVD/CD readers can be found in e.g. J. Braat, P. Dirksen, and A. Janssen, “Diffractive read-out of opticaldiscs,” inOptical Imaging and Microscopy, 2nd ed., edited by P. Törökand F.-J. KaoSpringer, Heidelberg, 2007, Chap.4.
Clause 2.2 should be significantly shortened
Author Response
1. The left side of equations 2 and 3 cannot be denoted in the same way.
Similarly the left side of equations 4 and 5 cannot be denoted in the same way.
Respond: We have changed them to subscript fonts already. For example: from "FES" to "FESCD and FESDVD".
- The description set out in point 2.2. has been known for nearly 40 years! and it was presented in many articles. A description of different versions of DVD/CD readers can be found in e.g. J. Braat, P. Dirksen, and A. Janssen, “Diffractive read-out of opticaldiscs,” inOptical Imaging and Microscopy, 2nd ed., edited by P. Törökand F.-J. KaoSpringer, Heidelberg, 2007, Chap.4.
Respond: Thank you for your fruitful suggestion. I am sure that this reviewer is an expertise in this field and so, he/she suggested to shorten part 2.2. However, some reviewer who may not concern in this field still does not understand about this conventional technique. So, I may apologize to ask you to permit us keeping this part 2.2. In addition, most of literature have used this technique in microbiology science or basic science but this is the first report that utilize it to scratch inspection on magnetic media disks.
Round 2
Reviewer 1 Report
Dear Authors, I understand that you are definding your paper in the responses, yet the issues addressed by the review remain unsolved. My "job" as a reviewer is to identify weak points, and I have done so. It is up to the editor to decide now.
Author Response
Dear Authors, I understand that you are definding your paper in the responses, yet the issues addressed by the review remain unsolved. My "job" as a reviewer is to identify weak points, and I have done so. It is up to the editor to decide now.
Answer: I have solved and answered all of reviewers' comments (comments or commands?). i have explained about the comments that some comments were constructive and right. But some comments were misunderstood and it is my job to let the reviewer understand my research.
For example, you gave a comment that there is no LeCroy waveAce 2010 oscilloscope but there are waveAce 2000.
This shows that the reviewer does not know that the WaveAce 2000 oscilloscope is not available for sale at all. BUT it represents the Big family or Big series of this product. In this paper, we used WaveAce2010 to show that this is a sub-series of the WaveAce2000. I can provide the reviewer more information about oscilloscope that the WaveAce 2010 has 2 products: 2012 and 2014 (xxx2= 2 channels and xxx4 = 4 channels, Do you think this is a seriously important issue?)
Anyway, I can make a revision of my paper by change "WaveAce2010" to "WaveAce2012" in line 81 to make the reviewer happy.
I have served as reviewers for many journals and many years, and never given authors any command to do more works outside of their interest. I always suggest them in academic concerns in terms of their works only and inspire them to improve their works. Unless the academic base is totally wrong, I will advise them to take a look in the right things. Not blame them, OK?
So, this is the first time of my entire life for 50 years to receive such comments. I beg the reviewer not to make such comments like these to other authors because it is discouraging researchers' willingness, particular the young ones.
Anyways, thank you the reviewer very much for spare time giving me some comments. I am nearly retired and wish to assist new researchers to develop themselves and their works. Good Luck.
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
The authors present data showing the use of CD/DVD heads to look at scratches on a sample. The use of such techniques is well known and examined across a number of fields and there are significant publications in the area, making it difficult to determine the novelty.
In terms of the data presented, it is limited to 3 scratches and there seems no real push to map a true 3d image of the scratch and compare to afm / sem data.
The errors given would seem very high and as such beyond showing there is a defect the true analysis would appear to be limited as a technique.
Reviewer 2 Report
First of all, it is interesting to see that it is possible, using sensors that are available at low cost, to detect scratches in media and measure their width. I appreciate the work invested to show this and implement a microcontroller based demonstrator.
My first criticism, however, is about the industrial need. It is already known in the state of the art (SoA) and described in section 1 that optical sensing using laser scanning and interferometry is applied industrially for scratch detection. In an industrial environment, the costs for the sensors alone are quite unimportat, as the majority of costs often comes from the mechanical side, reliability, perfection and software. So I see a low application relevance of the research and its innovation compared to the SoA.
Secondly, it is not well described what role the microcontroller has. It is rather trivial to use a microcontroller in a data acuiqision setup. Then, the authors mention an oscilloscope. Figure 3 suggests that the data acquistion is done with the microcontroller (sensor only connected to µC - no oscilloscope). Is the microcontroller only used for controlling the HDD motor and focusing? This is not well described.
Figure 1, which is very crude, indicates that the scratches go over the full radius. Is this a realistic scenario, and how long would it take to scan an HDD if the scratches were shorter? What are industrial requirements, compared to SoA performance?
The probability of detection is not discussed. What is the minimum scratch size safely detectable? How does this compare to the industrial needs and the performance of SoA systems?
The second graph in figure 7 is too small.
When comparing the error using SEM for reference, was the optical detection really done at exactly the same spot where the preparation for SEM was done? How do the authors judge that a 25% error is acceptable, can they provide a reference?
Funding note: Template text should be deleted if not required
Language and grammar need improvement, articles are frequently missing, and misspelled words occur.
