View source for Laser turntable

{{Short description|Turntable that plays records using laser beams}}
{{Use dmy dates|date=February 2024}}
[[File:Elp-rme-02.jpg|thumb|ELP Laser turntable (LT-2XA) and RME Fireface 800]]
A '''laser turntable''' (or '''optical turntable''') is a [[phonograph]] that plays standard [[LP record]]s (and other [[gramophone record]]s) using [[laser]] beams as the [[Phonograph cartridge|pickup]] instead of using a [[Phonograph#Stylus|stylus]] as in conventional [[phonograph#Turntable technology|turntables]].  Although these turntables use [[Magnetic cartridge|laser pickups]], the same as [[CD player|Compact Disc players]], the signal remains in the [[Analog signal|analog realm]] and is never [[Digitization|digitized]].

==History==
William K. Heine presented a paper "A Laser Scanning Phonograph Record Player" to the 57th [[Audio Engineering Society]] (AES) convention in May 1977.<ref>Heine, William K. [http://www.aes.org/e-lib/browse.cfm?elib=3098 "A laser scanning phonograph record player."] Audio Engineering Society Convention 57. Audio Engineering Society, 1977.</ref> The paper details a method developed by Heine that employs a single 2.2&nbsp;mW [[helium–neon laser]] for both tracking a record groove and reproducing the stereo audio of a phonograph in real time. In development since 1972, the working prototype was named the "LASERPHONE", and the methods it used for playback was awarded U.S. Patent 3,992,593 on 16 November 1976.<ref>{{cite web |url=https://patents.google.com/patent/US3992593A/en |title=Patent US3992593 – Disc phonograph record playback by laser generated diffraction pattern – Google Patents |access-date=23 October 2011 |archive-date=29 January 2014 |archive-url=https://web.archive.org/web/20140129043547/http://www.google.com/patents/about/3992593_Disc_phonograph_record_playback.html?id=UxI0AAAAEBAJ |url-status=live }}</ref> Heine concluded in his paper that he hoped his work would increase interest in using lasers for phonographic playback.

===Finial===
Four years later in 1981 Robert S. Reis, a graduate student in engineering at [[Stanford University]], wrote his master's thesis on "An Optical Turntable".<ref>{{cite web |url=http://www.senderogroup.com/about/reis.htm |title=Robert Reis Resum&#233 |publisher=Senderogroup.com |access-date=23 October 2011 |archive-url=https://web.archive.org/web/20111116213740/http://www.senderogroup.com/about/reis.htm |archive-date=16 November 2011 |url-status=dead }}</ref> In 1983 he and fellow Stanford electrical engineer Robert E. Stoddard founded '''Finial Technology''' to develop and market a laser turntable, raising $7 million in [[venture capital]]. In 1984 servo-control expert Robert N. Stark joined the effort.<ref>{{cite web |url=http://patent.ipexl.com/inventor/Robert_N_Stark_1.html |title=Robert N Stark – Inventor Patent Directory, Page 1 |publisher=Patent.ipexl.com |access-date=23 October 2011 |archive-date=15 March 2014 |archive-url=https://web.archive.org/web/20140315232226/http://patent.ipexl.com/inventor/Robert_N_Stark_1.html |url-status=live }}</ref><ref>The development of and technology behind the Finial turntable was covered in depth in Stereophile. See the August 1986, October 1988, January, February, and November 1989, July 1990, and June 1991 issues.</ref>

A non-functioning mock-up of the proposed Finial turntable was shown at the 1984 [[Consumer Electronics Show]] (CES), generating much interest and a fair amount of mystery, since the patents had not yet been granted and the details had to be kept secret.<ref>{{US patent|4870631}}</ref> The first working model, the Finial '''LT-1''' (Laser Turntable-1), was completed in time for the 1986 CES. The prototype revealed an interesting flaw of laser turntables: they are so accurate that they "play" every particle of dirt and dust on the record, instead of pushing them aside as a conventional stylus would. The non-contact laser pickup does have the advantages of eliminating record wear, tracking noise, turntable rumble and feedback from the speakers, but the sound is still that of an LP turntable rather than a Compact Disc. The projected $2,500 street price (later raised to $3,786 in 1988) limited the potential market to professionals (libraries, radio stations and archivists) and a few well-heeled audiophiles.<ref>{{cite web
  | last = Orban
  | first = Robert
  | title = Maintaining Audio Quality in the Broadcast Facility – 2008 Edition
  | url = ftp://ftp.orban.com/Audio_Quality/Maintaining_Audio_Quality_in_the_Broadcast_Facility_2008.pdf
  | accessdate = 25 June 2008
  | archive-url = https://web.archive.org/web/20201017174247/ftp://ftp.orban.com/Audio_Quality/Maintaining_Audio_Quality_in_the_Broadcast_Facility_2008.pdf
  | archive-date = 2020-10-17
  | url-status = dead
  | quote = Page 39 – Production facilities specializing in high-quality transfer of vinyl to digital media should consider supplementing their conventional turntable with an ELP Laser Turntable(9) Instead of playing disks mechanically, this pricey device plays vinyl without mechanical contact to the disk, using laser beams instead.}}</ref>

The Finial turntable never went into production.  After Finial showed a few hand-built (and finicky)<ref>{{cite web |author=Steven R. Rochlin |url=http://www.enjoythemusic.com/magazine/viewpoint/0404/aachapter55.htm |title=Bill Gaw AA Chapter 55: ELP Laser Turntable |publisher=Enjoythemusic.com |access-date=23 October 2011 |archive-date=2 April 2012 |archive-url=https://web.archive.org/web/20120402192855/http://www.enjoythemusic.com/magazine/viewpoint/0404/aachapter55.htm |url-status=live }}</ref> prototypes, tooling delays, component unavailability (in the days before cheap lasers), marketing blunders, and high development costs kept pushing back the release date.  The long development of the laser turntable exactly coincided with two major events, the [[early 1980s recession]], and the introduction of the Digital [[CD|Compact Disc]], which soon began flooding the market at prices comparable to LPs (with CD players in the $300 range). Vinyl record sales plummeted, and many established turntable manufacturers went out of business as a result.

With over US$20 million in venture capital invested, Finial faced a marketing dilemma: forge ahead with a selling price that would be too high for most consumers, or gamble on going into mass production at a much lower price and hope the market would lower costs.  Neither seemed viable in a rapidly-shrinking market.

===ELP===
Finally, in late 1989 after almost seven years of research, Finial's investors cut their losses and liquidated the firm, selling the patents to Japanese turntable maker CTI Japan, which in turn created [[ELPJ|ELP Japan]] for continued development of the "super-audiophile" turntable. After eight more years of development the laser turntable was finally put on sale in 1997 – twenty years after the initial proposal – as the '''ELP LT-1XA''' Laser Turntable, with a list price of US$20,500 (in 2003 the price was lowered to US$10,500).<ref>{{cite web |url=http://www.audioturntable.com/ |title=ELP Laser Turntable: plays vinyl records without a needle, presented by Audioturntable, Ltd |publisher=Audioturntable.com |access-date=23 October 2011 |archive-date=5 November 2011 |archive-url=https://web.archive.org/web/20111105231948/http://www.audioturntable.com/ |url-status=live }}</ref>
The turntable, which uses two lasers to read the groove and three more to position the head, does allow one to vary the depth at which the groove is read, possibly bypassing existing record wear. It will not, however, read clear or [[Unusual types of gramophone records|colored vinyl]] records.<ref name=":0">{{cite web |last=Valin |first=Jonathan |url=http://www.theabsolutesound.com/articles/elp-lt-1lrc-laser-turntable/ |title=ELP LT-1LRC Laser Turntable |publisher=The Absolute Sound |date=24 November 2008 |access-date=3 July 2013 |archive-date=7 March 2014 |archive-url=https://web.archive.org/web/20140307011027/http://www.theabsolutesound.com/articles/elp-lt-1lrc-laser-turntable/ |url-status=live }}</ref> ELP sells built-to-order laser turntables directly to consumers in two versions (LT-basic, and LT-master),<ref>{{Cite web|url=http://elpj.com/ltfeaturesandspecs/|title=LT Specifications {{!}} ELP Laser Turntable|website=elpj.com|language=en-US|access-date=2017-10-11|archive-date=4 October 2017|archive-url=https://web.archive.org/web/20171004075952/http://elpj.com/ltfeaturesandspecs/|url-status=live}}</ref> at a reported cost (unpublished) of approximately $16,000 for the basic model.<ref>{{Cite web|url=http://diffuser.fm/laser-turntable/|title=The World's Only Commercially-Sold Laser Turntable|website=Diffuser.fm|date=4 May 2015 |language=en-US|access-date=2017-10-11|archive-date=12 October 2017|archive-url=https://web.archive.org/web/20171012002519/http://diffuser.fm/laser-turntable/|url-status=live}}</ref>

===Optora===
In May 2018, Almedio of Japan, a computer drive manufacturer,<ref>{{Cite web |url=https://www.almedio.co.jp/en/ |title=ALMEDIO INC. {{!}} 株式会社アルメディオ<!-- Bot generated title --> |date=9 June 2020 |access-date=6 August 2020 |archive-date=1 October 2020 |archive-url=https://web.archive.org/web/20201001070357/https://www.almedio.co.jp/en/ |url-status=live }}</ref> presented the '''Optora ORP-1''' optical (laser) turntable at the HIGH END Munich audio show.<ref>{{cite web |url=https://hifipig.com/decks-and-the-city-turntables-at-munich-high-end-2018/ |title=Decks And The City – Turntables At Munich High-End 2018 |date=16 May 2018 |publisher=HiFi Pig |access-date=4 August 2020 |archive-date=31 July 2018 |archive-url=https://web.archive.org/web/20180731114652/http://hifipig.com/decks-and-the-city-turntables-at-munich-high-end-2018/ |url-status=live }}</ref> Few details were provided by the company<ref>{{cite web |url=http://www.almedio.co.jp/assets/img/optora/optora_pdf02.pdf |title=Optora 2018 Product Catalog |date=1 April 2018 |archive-url=https://web.archive.org/web/20180613130208/http://www.almedio.co.jp/assets/img/optora/optora_pdf02.pdf |archive-date=13 June 2018 |url-status=dead }}</ref> because, like the 1984 presentation of the Finial turntable, the Optora was a non-working mockup.  Company representatives indicated the turntable would use five lasers and be belt-driven,<ref>{{Cite web |url=https://www.audiocircle.com/index.php?topic=157618.0 |title=OPTORA Optical Turntable another try at playing LPs with a laser<!-- Bot generated title --> |access-date=6 August 2020 |archive-date=18 November 2021 |archive-url=https://web.archive.org/web/20211118105125/https://www.audiocircle.com/index.php?topic=157618.0 |url-status=live }}</ref> like the ELP.  However, after producing some promotional materials (since deleted), a price was never announced<ref>{{Cite web |url=https://www.cnet.com/pictures/best-turntables-you-can-buy-from-affordable-to-absolute-insanity/20/ |title=Best turntables you can buy, from affordable to absolute insanity |publisher= CNET |access-date=6 August 2020 |archive-date=6 April 2023 |archive-url=http://web.archive.org/web/20230406023806/https://www.cnet.com/pictures/best-turntables-you-can-buy-from-affordable-to-absolute-insanity/20/ |url-status=live }}</ref> and the Optora has not been put on the market.  The company's website devoted to the turntable has since been deleted.<ref>{{Cite web |url=http://www.almedio.co.jp/optora/ |title=Optoraのご紹介｜株式会社アルメディオ |work=株式会社アルメディオ |access-date=6 August 2020 |archive-date=14 November 2018 |archive-url=https://web.archive.org/web/20181114221300/http://www.almedio.co.jp/optora/ |url-status=live }}</ref>

== Performance==
In a 2008 review of the model ELP LT-1LRC, Jonathan Valin in ''[[The Absolute Sound]]'' claimed: {{quote|"If I were to describe its presentation in a few words, they would be 'pleasant but dull'."<ref name="valin2008">{{cite web |url=https://www.theabsolutesound.com/articles/elp-lt-1lrc-laser-turntable/ |title=ELP LT-1LRC Laser Turntable |first=Jonathan |last=Valin |date=2008-11-24 |accessdate=2024-03-27 }}</ref>}}

Valin commended the tonal accuracy of playback, but criticized the lack of [[dynamic range]] and bass response (limitations of the vinyl records themselves). He emphasized that records must be wet-cleaned immediately before playback because: {{quote|"Unlike a relatively massive diamond stylus, which plows through a record’s grooves like the prow of a ship, the ELP’s tiny laser-beam styli have next to no [[mass]] <!--[sic]:spelling actually correct--> and cannot move [[Dust|dust particles]] out of their way. Any speck of dirt, however minute, is read by the lasers along with the music."<ref name="valin2008" />}}

In 2008, Michael Fremer noted in ''[[Stereophile]]'': {{quote|"...consider the LT's many pluses: no rumble or background noise of any kind; no cartridge-induced resonances or frequency-response anomalies; no compromise in channel separation (the ELP guarantees channel separation in excess of what the best cutter heads offer); zero tracking or tracing error; no inner-groove distortion; no skating; no adjustments of VTA or azimuth to worry about; no tangency error (like the cutter head itself, the laser pickup is a linear tracker); no record wear; a claimed frequency response of 10Hz–25kHz; and, because the laser beam is less than a quarter the contact area of the smallest elliptical stylus, it can negotiate sections of the engraved waveform that even the smallest stylus misses."<ref name="fremer2018"/>}}

Fremer also noted, however, that all of this comes at a cost: {{quote|"[T]he LT-2XRC's laser pickup was unable to distinguish groove modulations from dirt. Records that sound dead quiet on a conventional turntable could sound as if I was munching potato chips while listening to the ELP. Bummer. There's a solution, of course: a record-cleaning machine. This can't be considered an 'accessory' with the LT: it's mandatory. Even new records fresh out of the jacket can sound crunchy."<ref name="fremer2018">{{Cite web |url=https://www.analogplanet.com/content/analog-corner-101 |title=Analog Corner #101 &#124; Analog Planet |date=2018-11-12 |access-date=2020-10-10 |archive-date=2020-08-04 |archive-url=https://web.archive.org/web/20200804142054/https://www.analogplanet.com/content/analog-corner-101 |url-status=live |first=Michael |last=Fremer }}</ref>}}

Fremer concludes: {{quote|"Ironically, if you listen to the music itself, you won't know you're listening to an LP. It's almost like a reel-to-reel tape. Unfortunately, when there is noise, it will always make you aware that you're listening to an LP. That's the confounding thing about this fabulous contraption."<ref name="fremer2018"/>}}

==Optical record scanning==
A similar technology is to scan or photograph the grooves of the record, and then reconstruct the sound from the modulation of the groove revealed by the image. Research groups that developed this technology include:
* [[IRENE (technology)|IRENE]] developed by physicists Carl Haber and Vitaliy Fadeyev of the [[Lawrence Berkeley National Laboratory]]. Installed in the [[Library of Congress]] late in 2006, IRENE (for Image, Reconstruct, Erase Noise, Etc.)<ref>{{cite web |url=https://spectrum.ieee.org/particle-physics-resurrects-alexander-graham-bells-voice |title=Particle Physics Resurrects Alexander Graham Bell's Voice |last=Marsh |first=Allison |publisher=[[IEEE Spectrum]] |date=30 April 2018 |access-date=9 May 2018 |archive-date=10 May 2018 |archive-url=https://web.archive.org/web/20180510042237/https://spectrum.ieee.org/tech-history/dawn-of-electronics/particle-physics-resurrects-alexander-graham-bells-voice |url-status=live }}</ref> uses a camera rotating around the record and taking detailed photographs of the grooves. Software then uses the digital images to reconstruct the sound.<ref>{{cite web |url=https://www.smithsonianmag.com/videos/category/arts-culture/playing-the-unplayable-records |title=Playing the Unplayable Records |publisher=[[Smithsonian (magazine)|Smithsonian]] |date=24 June 2017 |access-date=9 May 2018 |archive-date=9 May 2018 |archive-url=https://web.archive.org/web/20180509033934/https://www.smithsonianmag.com/videos/category/arts-culture/playing-the-unplayable-records/ |url-status=live }}</ref> In 2018 the system was used to play, for the first time, the only known recording of [[Alexander Graham Bell]]'s voice.  IRENE often produces a large amount of hiss with the recording, but it is very capable of removing pops and clicks produced by imperfections on the record surface.<ref>{{cite web |url=https://www.npr.org/templates/story/story.php?storyId=11851842 |title=You Can Play the Record, but Don't Touch |last=Greenfieldboyce |first=Nell |publisher=[[NPR]] |date=15 July 2007 |access-date=1 April 2018 |archive-date=12 August 2007 |archive-url=https://web.archive.org/web/20070812180736/http://www.npr.org/templates/story/story.php?storyId=11851842 |url-status=live }}</ref>
* SAPHIR system developed at [[Institut national de l'audiovisuel|INA]] in 2002 (patented in France in 2004).<ref>{{cite web |url=http://recherche.ina.fr/eng/Details-projets/saphir |title=Saphir: Optical Playback of Analogue Audio Disc Records |publisher=[[Institut national de l'audiovisuel]] |date=2015 |access-date=2 March 2021 |archive-date=28 April 2021 |archive-url=https://web.archive.org/web/20210428092614/http://recherche.ina.fr/eng/Details-projets/saphir |url-status=live }}</ref>
* [[VisualAudio]] developed by the Swiss National Sound Archives and the School of Engineering and Architecture of Fribourg.
* A laser beam reflection method was developed by Japanese scientists in Hokkaido university in 1986 for the purpose of reading audio recordings of the [[Ainu language]] made on fragile wax cylinders.<ref>{{Cite journal |doi=10.1364/AO.25.000597 |title=Reproduction of sound from old wax phonograph cylinders using the laser-beam reflection method |year=1986 |last1=Iwai |first1=Toshiaki |last2=Asakura |first2=Toshimitsu |last3=Ifukube |first3=Tom |last4=Kawashima |first4=Toshio |journal=Applied Optics |volume=25 |issue=5 |pages=597–604 |pmid=18231220 |bibcode=1986ApOpt..25..597I }}</ref>

==See also==
* [[LaserDisc]]

==References==
{{reflist}}

== Bibliography ==
* Uozumi, Jun, and Toshimitsu Asakura. "Reproduction of sound from old disks by the laser diffraction method." Applied optics 27.13 (1988): 2671-2676.
* Nakamura, Takashi, et al. "[https://spie.org/ETOP/1997/304_1.pdf Optical reproduction of sounds from old phonographic wax cylinders.]" Proceedings of SPIE. Vol. 3190. 1997.
* Uozumi, Jun, and T. Asakura. "[http://www.eli.hokkai-s-u.ac.jp/HRC/activities/1999/09.pdf Optical methods for reproducing sounds from old phonograph records.]" International Trends in Optics and Photonics: ICO IV (1999): 409-425.
* Uozumi, Jun, Tsuyoshi Ushizaka, and Toshimitsu Asakura. "[http://eng.hgu.jp/hrc/activities/2000/03.pdf Optical reproduction of sounds from negative phonograph cylinders.]" Optics and Lasers in Biomedicine and Culture: Contributions to the Fifth International Conference on Optics Within Life Sciences OWLS V Crete, 13–16 October 1998. Springer Berlin Heidelberg, 2000.
* Asakura, Toshimitsu, et al. "[http://eng.hgu.jp/hrc/activities/2000/01.pdf Study on reproduction of sound from old wax phonograph cylinders using the laser.]" Optics and Lasers in Biomedicine and Culture: Contributions to the Fifth International Conference on Optics Within Life Sciences OWLS V Crete, 13–16 October 1998. Springer Berlin Heidelberg, 2000.
* ASAKURA, Toshimitsu. "[https://www.jsap.or.jp/jsapi/Pdf/Number06/05_CuttingEdge2.pdf Research and reconstruction of art and acoustic cultural heritage by means of optical methods.]" JSAP international 6 (2002): 12-19.
* Fadeyev, Vitaliy, and Carl Haber. "[https://www.osti.gov/servlets/purl/823748 Reconstruction of mechanically recorded sound by image processing.]" Journal of the Audio Engineering Society 51.12 (2003): 1172-1185.
* Stotzer, Sylvain, et al. "[https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=2beecf259835a54e8dfb65e25b9c6ffca1112f14 Visualaudio: an optical technique to save the sound of phonographic records.]" IASA Journal (2003): 38-47.
* Penn, William A., and Martha J. Hanson. "[https://surface.syr.edu/cgi/viewcontent.cgi?referer=&httpsredir=1&article=1044&context=sul The Syracuse University Library Radius Project: Development of a non-destructive playback system for cylinder recordings.]" First Monday 8.5-5 (2003).
* McCann, M., P. Calamia, and N. Ailon. "Audio Extraction from Optical Scans of Records." (2004).
* Stotzer, Sylvain. [https://doc.rero.ch/record/7958/files/StotzerS.pdf Phonographic record sound extraction by image processing.] Diss. Université de Fribourg, 2006.
* Tian, Baozhong, and John L. Barron. "[https://www.researchgate.net/profile/Das-Arpita/publication/287759869_Object_recognition_using_Artificial_Neural_Network_Case_studies_for_noisy_and_noiseless_images/links/5679231308ae6041cb49eba8/Object-recognition-using-Artificial-Neural-Network-Case-studies-for-noisy-and-noiseless-images.pdf#page=93 Reproduction of sound signal from gramophone records using 3d scene reconstruction.]" Irish Machine Vision and Image Processing Conference. 2006.
* Li, Beinan, Simon de Leon, and Ichiro Fujinaga. "[https://archives.ismir.net/ismir2007/paper/000165.pdf Alternative Digitization Approach for Stereo Phonograph Records Using Optical Audio Reconstruction.]" ISMIR. 2007.
* Cornell, Earl W., et al. "[https://escholarship.org/content/qt0p0450kq/qt0p0450kq.pdf Using optical metrology to reconstruct sound recordings.]" Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 579.2 (2007): 901-904.
* Aleksandrović, Vesna. "[http://elib.mi.sanu.ac.rs/files/journals/ncd/12/ncd12037.pdf Analog/digital sound. National Library of Serbia digital collection of 78 rpm gramophone records.]" Review of National Center for Digitization 12 (2008): 37-42.
* Boltryk, P. J., et al. "Noncontact surface metrology for preservation and sound recovery from mechanical sound recordings." Journal of the Audio Engineering Society 56.7/8 (2008): 545-559.
* Li, Beinan, Jordan BL Smith, and Ichiro Fujinaga. "[https://archives.ismir.net/ismir2009/paper/000122.pdf Optical Audio Reconstruction for Stereo Phonograph Records Using White Light Interferometry.]" ISMIR. 2009.
* Canazza, Sergio, and Antonina Dattolo. "[https://sasweb.uniud.it/papers/2010-canazza-dattolo-sac.pdf Listening the photos.]" Proceedings of the 2010 ACM Symposium on Applied Computing. 2010.
* Tian, Baozhong, Samuel Sambasivam, and John Barron. "Practical digital playback of gramophone records using flat-bed scanner images." Audio Engineering Society Convention 131. Audio Engineering Society, 2011.
* Hayes, James. "Lasers get groovy." Engineering & Technology 6.11 (2011): 58-59.
* Janukiewicz, Kristofer. "[https://www.diva-portal.org/smash/get/diva2:1056370/FULLTEXT01.pdf A Laser Triangulation Approach for Optical Audio Reconstruction of Phonograph Records.]" (2016).
* Chenot, Jean-Hugues, Louis Laborelli, and Jean-Étienne Noiré. "[https://hal.science/hal-01885324/file/JHChenot_Saphir_Optical_Playback_Damaged_Analogue_Audio_Discs_JOCCH2018_authors_v1.01.pdf Saphir: optical playback of damaged and delaminated analogue audio disc records.]" Journal on Computing and Cultural Heritage 11.3 (2018): 14-1.
* Chenot, Jean-Hugues, Louis Laborelli, and Jean-Etienne Noiré. "[https://recherche.ina.fr/content/download/787/3841/version/1/file/JHChenot_Saphir_Digitizing_Broken_Cracked_Delaminated_Lacquer_78rpm_Records_Desktop_Optical_Scanner_JTS2019_v1.00.pdf Saphir: Digitizing broken and cracked or delaminated lacquer 78 rpm records using a desktop optical scanner.]"
* Hawkins, Julia, and Bryce Roe. "[https://www.nedcc.org/assets/media/documents/JDMM_9_3_JDMM0008_Hawkins_and_Roe.pdf IRENE audio preservation at the Northeast Document Conservation Center: Developing workflows and standards for preservation projects that use innovative technology.]" Journal of Digital Media Management 9.3 (2021): 262-278.
* Chenot, Jean-Hugues, and Jean-Etienne Noiré. "[http://www.aes.org/e-lib/download.cfm/22135.pdf?ID=22135 Challenges in Optical Recovery of Otherwise Unplayable Analogue Audio Disc Records.]" Audio Engineering Society Conference: AES 2023 International Conference on Audio Archiving, Preservation & Restoration. Audio Engineering Society, 2023.
* [https://indico.cern.ch/event/1971/contributions/369313/attachments/289827/405131/VF-Carmel-2006.pdf Using Optical Metrology to Restore Sound Recordings]
* [https://www2.lbl.gov/LBL-Programs/wyp2005/assets/docs/Haber_Summer_Lecture.pdf Using Physics to Restore Early Sound Recordings]
* [https://www-cdf.lbl.gov/~av/LOC-2005-Public.pdf Reconstruct Sound Recordings]

== External links ==
{{Commons and category|Category:ELP laser turntables}}
*[http://www.elpj.com/ ELP Japan website]
*[http://www.elpj.com/about/ ELPJ – About the laser turntable]
*[http://www.cs.huji.ac.il/~springer/ Record scanning] – [[Ofer Springer]]
*[http://irene.lbl.gov/ Record scanning using IRENE] – Sound Reproduction R & D Home Page
*[https://web.archive.org/web/20201021180935/http://www.fonoteca.ch/gallery/visualAudio/publications/040626_JTS.pdf Record scanning] – VisualAudio: An optical technique to save the sound of phonographic records
*[https://web.archive.org/web/20140418220727/http://www.jetro.go.jp/ttppoas/genki/elp.html Only One Company in the World for Laser Record Players to Play Vinyl Records] (archived 30-03-2024)[[Japan External Trade Organization]]
*[http://www.freepatentsonline.com/3992593.pdf United States Patent US3992593]
*[http://www.freepatentsonline.com/4870631.pdf United States Patent US4870631]
*[http://www.freepatentsonline.com/4972344.pdf United States Patent US4972344]
*[https://patents.google.com/patent/CA1285231C/ CA1285231C]

{{Optical storage media}}

{{DEFAULTSORT:Laser Turntable}}
[[Category:American inventions]]
[[Category:Audiovisual introductions in 1986]]
[[Category:Audio engineering]]
[[Category:Turntables]]