Talk:Optical disc

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stub[edit]

Is this article a stub? —Preceding unsigned comment added by 4.142.231.135 (talkcontribs) at 04:57, 31 July 2005 (UTC)

Tray or slot-in[edit]

Optical disc can be loaded with tray or slot-in thingymabob. —Preceding unsigned comment added by Frap (talkcontribs) at 15:01, 6 June 2006 (UTC) With an ODD on my laptop and other than buying an external CD drive, how do I get my original CDs' programs loaded? 68.201.92.229 14:07, 3 November 2007 (UTC) Olde Dave

CD and DVD[edit]

In my Computer Information Systems class we were told that there are two types of optical disks, the CD and the DVD. Now I'm reading this article and I'm like what the hell? Not that I trust my class over wikipedia. Obviously. Erik E. 02:20, 13 February 2007 (UTC)

Well, I think the article is a reasonably good and yet concise representation of the current situation. CD and DVD are by far the most common, being the most versatile, but Blu-Ray and HD-DVD are coming up fast, and MiniDisc, while on the way out, is still viable for personal recording. Much of the bestiary you see is variations on a theme, while a lot of it is either vaporware or experimental, or just plain never worked out (DataPlay, anyone?). Haikupoet 02:49, 13 February 2007 (UTC)

Who invented the optical disc[edit]

James T. Russell or David Paul Gregg ?--218.102.200.15 06:01, 11 October 2007 (UTC)

Classifications in generations[edit]

I do not think that classifications in generations explains the readers much. why not simply write CD, DVD etc. This tendency to classify products into generations seems to be a typical trait of the English Wikipedia which is fortunately not so strong in other Wikipedias. Andries (talk) 17:17, 26 January 2008 (UTC)

Introduction About Play Station black discs[edit]

Is PlayStation a toy, isnt more like a game console, i didnt know 30 year olds played with toys...the word should be change to PlayStation Game Console instead of "PlayStation Toy"EdwinCasadoBaez (talk) 03:57, 6 June 2008 (UTC)

12x[edit]

Down where it talks about the blu-ray read speed it says 12x but the referenced article only talks about 6x. Could someone who knows more about this either fix it or explain why it's that way?

72.220.68.143 (talk) 08:58, 18 July 2008 (UTC)

Spelling of "disk"?[edit]

Since when has the English language changed the spelling of "disk" to "disc"? OK, I recognise that Philips/Sony took out a trade mark for "Compact Disc", as they wanted their trade name to sound international and groovy. But for non-trade names, we really should use the plain English word "disk", as it is in every English dictionary. "Optical disc", the article title, is not a trade name. It should be changed to "Optical disk".--Lester 22:26, 2 September 2008 (UTC)

For what it's worth, the dictionary lists ‘disc’ as the primary spelling, noting that ‘disk’ is ‘chiefly US’.

History?[edit]

"The optical disc was invented in 1958."

Uhhh, no. Gilbert King was leading development of a read-only optical disk system at International Telemeter starting in 1953. They made numerous devices during development. After moving to IBM in 1958 he delivered a real working system to the Air Force in 1959, and by "working system" I mean a complete online data system with computer, disk, etc. My guess is that there were even earlier attempts, but I can't demonstrate that. What I can demonstrate is...

G.W. King, G.W. Brown and L.N. Ridenour, "Photographic Techniques for Information Storage", Proceedings of the IRE', Volume 41 Issue 10 (October 1953), pp. 1421-1428

Ridenour, BTW, was one of the co-developers of the SCR-584.

Maury Markowitz (talk) 19:03, 20 January 2009 (UTC)

ARE THIS OPTICAL DISC DESTROYED WHEN KEPT IN HIGH MAGNETIC FIELD?? —Preceding unsigned comment added by 67.193.111.132 (talk) 21:04, 26 March 2009 (UTC)

Additionally, why does the current version of the article tell me the optical disc was invented in 1958, yet it shows me a picture of an "analog optical disc" from 1935? These conflicting elements cause confusion. The orgel disc should not be a part of this article.173.28.60.82 (talk) 08:45, 24 April 2011 (UTC)

Comment: The discussion to ignore the prior inventions/products is nonsense. Rather, we should verify and correct the description, following the advice of the {{Original research}} tag. The analog optical disc based on sound film technology (one of the photographic techniques) was already put in practical use in Germany in 1930s, and it was re-invented in the United States after the WWII. Such re-inventions may be found in many other fields: for examples, modern electronic computers, microprocessors (half dozen of rivals had invented at that time), magnetic tape recorders, etc. --118.8.51.203 (talk) 04:02, 26 April 2011 (UTC)

Requested move[edit]

The following is a closed discussion of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the proposal was No move Parsecboy (talk) 01:35, 16 April 2009 (UTC)

  • Yes, that's a common misconception. In fact, the different disc/disk spellings are used by professional editors and in almost all reference works as explained here:

Computer specialists preferred the familiar k-spelling, while people in the music industry, who saw the shiny circular plates as another form of phonograph record, referred to them as compact discs. These tendencies soon became established practice in the different industries. This is why we buy compact disks in computer stores but get the same storage devices with different data as compact discs in music stores. Similarly, the computer industry created the optical disk, the format that the entertainment industry used to create the videodisc. [1]

  • Oppose my original IBM PC XT Hardware Manual says "hard disc drive" for magnetic media called harddrives now, and CDs and DVDs and MDs are optical - and use "disc". 70.29.213.241 (talk) 07:36, 11 April 2009 (UTC)
  • Comment what is your obsession with "k"? 70.29.213.241 (talk) 07:38, 11 April 2009 (UTC)
  • Oppose This is a tough one because both uses are common in technology, even astronomy. But "disc' appears to be the most widely used spelling for commercial optical discs, including CDs, DVDs, and Blu-Ray Discs. On the other side, "floppy disks" are pretty much obsolete and "hard disks" may soon follow, replaced by solid state devices. Here is a list of the current optical discs from the article:
   ** Blu-ray Disc (BD): BD-R, BD-RE
   ** DVD: DVD-R, DVD+R, DVD-R DL, DVD+R DL, DVD-RW, DVD+RW, DVD-RW DL, DVD+RW DL, DVD-RW2, DVD-RAM, DVD-D
   ** Compact Disc (CD): Red Book, CD-ROM, CD-R, CD-RW, 5.1 Music Disc, SACD, PhotoCD, CD Video (CDV), Video CD (VCD), SVCD, CD+G, CD-Text, CD-ROM XA, CD-i, HVD
   ** VCDHD
   ** GD-ROM
   ** MiniDisc (MD) (Hi-MD)
   ** Laserdisc (LD)
   ** Video Single Disc (VSD)
   ** Ultra Density Optical (UDO)
   ** Universal Media Disc (UMD)
   ** Holographic Versatile Disc (HVD)

Facts707 (talk) 13:46, 11 April 2009 (UTC)

  • Oppose "Disc" also seems to be the one used in anatomy (Intervertebral disc), which tends to outlast any technological inventions.Facts707 (talk) 13:46, 11 April 2009 (UTC)
  • Oppose --Flash176 (talk) 14:51, 11 April 2009 (UTC)
  • Comment Have any of you voting oppose looked at the links provided that clearly show that apparently all US and UK dictionaries and encyclopedias use the spelling "optical disk"? Unless you provide sources for your claims about the spelling "optical disc" being more common, your votes are worthless.--Espoo (talk) 07:57, 12 April 2009 (UTC)
  • Check again Many of the encyclopedia references above contradict the requester or are ambivalent.
    • All of the UK dictionaries have a listing under "disc", then say "disk" is an alternate American spelling. Also they do not list "optical disk" or "optical disc" as unique entries. Eg:
      • Longman: disc "also disk especially American English"
      • Chambers: "disc noun 1 a flat thin circular object. 2 any disc-shaped recording medium, such as a record (noun 4), compact disc or video disc"
    • Webopedia: disc

Last modified: Sunday, September 01, 1996 Alternative spelling of disk . Disc is often used for optical discs, while disk generally refers to magnetic discs, but there is no real rule.

 optical disc computer technology
 Aspects of this topic are discussed in the following places at Britannica.
 Assorted References
  ===major reference ( in information processing: Recording media )
     An entirely different kind of recording and storage medium, the optical disc, became available during the early 1980s. The optical disc makes use of laser technology: digital data are recorded by burning a series of microscopic holes, or pits, with a laser beam into thin metallic film...
   === information storage ( in computer memory: Optical discs;

Another form of largely read-only memory is the optical compact disc, developed from videodisc technology during the early 1980s. Data are recorded as tiny pits in a single spiral track on plastic discs that range from 3 to 12 inches (7.6 to 30 cm) in diameter, though a diameter of 4.8 inches (12 cm) is most common. The pits are produced by a laser or by a stamping machine and are read by a... ... Facts707 (talk) 19:45, 12 April 2009 (UTC)

  • Facts707, the only one of the reference works linked to above that is ambivalent is Britannica, which mostly uses "optical disk" but does in fact sometimes also use the spelling "optical disc", as you showed. This kind of inconsistency is extremely unusual in a reputable source and is no doubt caused by Britannica's habit of trying to use spelling that upsets neither UK nor US readers so that the encyclopedia can be sold in all English-speaking countries without changing the spelling. This is highly unusual and arguably unique in the publishing business at least in a major publication. In any case, Britannica's use of both spellings for "optical disk" proves that both spellings are widely used.
  • The only one of my encyclopedia references above that doesn't support my request is Chambers, which I read too quickly, and has the spelling "disk" only for computer disks (disk: computing a magnetic disk. See also floppy disk, hard disk.)
  • You misunderstood and incorrectly quoted sources as explained here:
    • Yes, all of the UK dictionaries have a listing under "disc" and then say "disk" is an alternate American spelling, but my UK references also show that "disk" is not only the US spelling for the general sense of disc/disk but also a normal or at least accepted UK spelling for the sense "hard disk" and "optical disk", for example Longman, which you quoted incorrectly (my emphases):
      • Longman: disk: 1 a small flat piece of plastic or metal which is used for storing computer or electronic information 2 the usual American spelling of disc
      • Webopedia: disc: Alternative spelling of disk . Disc is often used for optical discs, while disk generally refers to magnetic discs, but there is no real rule.
      • In combination with the same (US) encyclopedia's entry "optical disk"[2], which uses only this spelling, this again shows that "optical disk" is the normal US spelling (as well as an accepted and common UK spelling). --Espoo (talk) 10:00, 15 April 2009 (UTC)
The above discussion is preserved as an archive of the proposal. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Flash memory more reliable?[edit]

This says that flash memory is more reliable. Flash memory only lasts about 10 years - hardly reliable. Optical discs can last up to 100 years or more (for high-end brands, eg. Taiyo Yuden or MAM-A). —Preceding unsigned comment added by 174.111.242.33 (talk) 21:53, 26 October 2010 (UTC)

Solid state card-like optical media?[edit]

A long time ago (early to mid 90's?) I recall seeing a bit in a magazine (Popular Science?) about a business card size optical "disc" that didn't spin, but was read without moving parts and the surface looked like and was shiny just like CD's and DVD's. In fact, were a CD or DVD cut precisely and cleanly into a rectangle (obviously smaller than an actual business card as the central hub would be part of such a disection) it would look just like what I saw. Google searches turned up nothing resembling this and it wasn't a bootable business card or Shaped Compact Disc. Maybe I'm just remembering this incorrectly and/or didn't understand what it was I was looking at, but should this have existed (Is solid state optical media even possible or is spinning a necessity?), would it warrant a mention? —Preceding unsigned comment added by 4.254.86.87 (talk) 01:02, 14 February 2011 (UTC)

Got it. It was called the Hi-Lite Card, was larger than I thought-the size of a business card-and held 200MB. Impressive for 1987. I did read about it in Popular Science and actually still own that particular issue, but didn't find the article until now since all the issues are now available on Google books. Anyway, it was an example of solid state optical media and I wonder why it or anything like it never caught on. — Preceding unsigned comment added by 4.254.82.197 (talk) 00:00, 4 June 2011 (UTC)

Article Quality[edit]

What is going on with this one? The whole second half reads like a cross between an ad for blu-ray and a badly copypasta'd high school book report. — Preceding unsigned comment added by 66.87.91.3 (talk) 05:16, 21 October 2011 (UTC)

Invented in 1884?[edit]

It seemed someone had rediscovered the earliest known optical disc invented in Volta Laboratory Associates through Smithsonian archives.[3] 142.150.48.218 (talk) 00:23, 20 December 2011 (UTC)

You can also hear what those discs sound like, as well as the related 1888 research article. - [4] 142.150.48.218 (talk) 00:58, 20 December 2011 (UTC)

Incorrect explanation of physical phenomenon[edit]

In the lead we have "The pits or bumps distort the reflected laser light, hence most optical discs (except the black discs of the original PlayStation video game console) characteristically have an iridescent appearance created by the grooves of the reflective layer." This sounds pretty impressive but it is actually wrong. If you look at a blank CD-R, you will see the same iridescent appearance (rainbow look) regardless of the fact that there are no "pits or bumps" since no recording has taken place. More disturbingly, the above sentence contains a link to Iridescence which correctly identifies Thin-film interference as the "physical phenomenon" taking place. A lucid explanation of the physics involved can be seen here. CaesarsPalaceDude (talk) 01:31, 4 October 2014 (UTC)

A CD-R has no pits or bumps ... but it does have grooves right? I thought the rainbows were a diffraction grating effect from the grooves... --Steve (talk) 14:11, 8 October 2014 (UTC)
Either way, the statement is uncited. I'd say cull it until we have a reliable source for it. The lead is a bit long as it is, and is primarily unsourced content. 0x0077BE [talk/contrib] 14:18, 8 October 2014 (UTC)

Here are some sources:

Thin-film iridescence:

Diffraction:

Seems to me the balance is in favor of diffraction, though mostly from educational sources, not pure science ones. That last book, however, is a much more pure-science type source. 0x0077BE [talk/contrib] 15:01, 8 October 2014 (UTC)

Howstuffworks and Explainthatstuff are much much much much less reliable than Physics Education, The Physics Teacher, etc.
If you use a CD like a mirror, and look at your face in specular reflection, the colors will be slightly off, and it's entirely possible that this is partially due to thin-film interference. But that's not what's at issue. We're talking about those dramatic rainbows. They show up to the sides of the reflection of a bright light source, proof that it is a diffraction effect.
I did a lab once in high school where you bounce a laser pointer off a (I think) blank CD-R. You get like 5 or 6 reflections at different angles, and you can use the diffraction grating equation to compute the CD's groove spacing :-D --Steve (talk) 17:50, 8 October 2014 (UTC)
Yes, this was a common theme I found among the references. I've added two of these references to the article and re-worded somewhat to clarify that the situation doesn't require the pits and bumps. I'm not entirely satisfied with the wording and the fact that the word "grooves" is not used in the remainder of the article, so feel free to play with the wording if you can come up with something better.
I also think that the lead really needs to be trimmed, and the article re-organized somewhat. Probably lead and history can be tightened up considerably and we can add a "composition" section and move all the stuff about materials and layers there, we can add a subsection there for "iridescence" using some of the citations above to briefly describe the reason those look like a rainbow. 0x0077BE [talk/contrib] 19:24, 8 October 2014 (UTC)
Thankyou so much, friends. I can see a huge improvement in those 2 sections of the article, and I've learnt a thing or two as well. I have reversed the order of 2 sentences in the lead, because I think it makes more sense that way. Feel completely free to check that it is an improvement. I agree that the lead is too long, however I won't be able to help because most of my work at WP is in the Music related articles. Keep up the great work. CaesarsPalaceDude (talk) 07:23, 9 October 2014 (UTC)