CA2134325C - High data rate optical tape recorder - Google Patents

Abstract

The optical tape recorder of the present invention is capable of archiving data at rates in excess of 400 megabits per second by concurrently writing or reading a plurality of data tracks in each data trace. A read-write module (102) outputs an illumination beam (104) comprised of combined multiple write beams (channels);
a read beam and an autofocus beam. Optics within tha read-write module spatially combine and accurately position the plurality of beams with respect to each other to farm the mufti-beam illumination beam (104). A read-write head (106) comprised of a synchronized scanning transmissive polygon (110) and rotating lens wheel (112) scans the multi-beam illumination beam ,(104) across a recording media (108) to read or write mufti-channel data tracks. An autofocus system is also included to ensure that the multi-beam illumination beam (104) is accurately focused on the recording media (108).

Description

t ~~, '!~'~ 93/22765 .,. PC'T/US93/03602 t:.~':S

t ~~.3~~.2~ , i~~ 93/2765 , . P(~lf'/US93/U36t12 ::... .: ,; . '. .. ~"'v'.
. - 2 ~ .._ B13CKOROL1ND OF THE IN~IENTION
Magnetic tape recording systems are widely used to archive digital information, but have historically been la ued b erformance and stora a p g Y P g problems that render their continued use for high volume information storage unacceptable. For example, due to the relatively low storage density c~f the magnetic recording media, a large number of expensive tape reels or cassettes are required to store the infor$nation. Furthermore, the mechanical devices and parts used in providing a storage system for the reels and cassettes of recorded media often require expensive and time c~nsuming maintenance and/or complete replacement.
The ~agn~tic tapes must also be repacked every six months to account for tape stretch an,d rerecorded every five to en years in order to preserve data integrity.
pgtical' systems are now a~masoraly used in place of magnetic systems far r~cdrdinc~ and playback of digitized information. Ira ~ptical recorders, the data is used to amplaaude modulate a. light la~a~ ha~~ing a predetermined intensity nedessary to dark a light sensitive recording media. The ~todul.ated beam i.s focused to a small spot and ~,r~c~d across the media to record the data as a fine optical pattern coanprised oaf a number of closely spaced, t~icrascopic dots (data marks) along a data track. To recover the reworded data from the optical media, a low .., .. . , . .., :: . : . _: .~ : ,.; :. :: ,.,, , .: , , : .. :. v: ~.

.. , W~ 93/22765 c PCT/US93/fl3602 ~,~~''~ ~~~ ~~~
W w . a intensity illumination beam is scanned along the data track and modulated by the opta:cal pattern recorded therein. The i modulated beam is reflected from the media to illuminate a Light detector producing an electrical signal in accordance ~ with the beam modulation for recovery of the recorded data.

Optical recording and playback systems have proven to prQVide enhanced performance characteristics over magnetic systems: The microscopic optical pattern of data recorded on the recording media by an optical system dramatically .increases bhe data storage density over conventional magnetic systems. Furthermore, there is a decr~~eased susceptibility to type .stretch and ~rsar with optical playback systems 'bee~useunlike magnetic systems,' there is active optical tracking during tk~e reading process with no contact between the read heaid and the media. Accordingly, data life on the media i:s increase's to over twenfiy years.

Fina:lly,' because'significantly moredata can be-stored by optical systems, the complexity of an archiving system (and requa.red space) for storing recording media reels and 9, t cassettes is significantly reduced. i The problem with present optical recording and v playback sys~e~n: >technology, however; is!: lew record anc3' .

playback data rates. Currently available ~~lhigh speed's ~ptiGal recording systems provide only a three megabyte (twenty-dour megabits) per second record nr read rate. ~t _::__.._...r _..... ._........,-..,... :..,..,.....-......---.-,-- r.-.
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;. x i that rate, it would take nearly four full days to record or playback one terabyte of digital data. For current and future needs, record and playback rates on the order of three megabytes per second are unacceptably slow. The National Aeronautics and Space Administration, for example, anticipates a data rate of 500 megabits per second by the year 21300 for the Desp Space Network. This is far too much data; on the order of a five terabyte per day archive rate, ~c~r conventional Qpti~al systems to handle. Accordingly, ;
there is a need f~r an improved optical data storage and playback apparatus capable of handling data input and o~,tput rates in excess of 400 megabits per second.
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i~~ 93J2276S ~ '~ ~ PC.'TJUS93/03602 ~~'~.;y,~s . .
SLTf~~ARY OF TH~ ~NVENTTON
Conventional optidal recording and playback systems amplitude modulate a single beam of light with digital data to record at a rate of approximately twenty-four megabits 5 per second. The optical tape recorder of the present invention is capable of archiving and retrieving data at rates in excess of BOO megabias per second by concurrently writing and/or reading a plura~.ity of data tracks in each data trace scanx~~d across the light sensitive recording media: Each of the data tracks (channels? with a multi-channel data trace records a different predetermined portion of the data: Thus, the effective read or write rite is a,ncrease~ over conventional systems by a factor equivalent to the number of data tracks combined and 1,5 concurrently written o~ read in each mufti-channel data Mace: Thzs multi~ch~nnel read anted write scheme pravides enhanced data capacity performance over conventional magnetic dnd sa.nc~le channel opt~.ca3 systems.
To ach~.eve a multiple data track ger data Mace record and read, the optical recox°der of the present invention utilize a mead-write ~nodul~ that outputs a mufti-beam ,allum,inat~.on beam for the data trace including: a mul~i' channel write beam t~ x~e>~~xd multiple data tracks in each data tracer a read beam that sans the mufti-channel data trace to recover the multiple data tracks of recorded data;
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f r,., .' ~ ~e q ~ :~ a !~~ 93/22'76 PCT/US931036~2 -~-and an autofocus beam to assist in focusing the mufti-channel write beam and read beam combined within the mufti-beam illumination beam on the surface of the recording t media . Recording and reading multiple data tracks per data trace reguires accurate combination of the multiple write, read and autofocus beams into the mufti-beam illumination beam for scanning across the media. To accomplish this cc~mb~.nation, the read-write module includes spatial combining optics and pointing and' translating optics to 1.0 deflect the beams together and accurately position and orient the multiple write, read and autofocus beams with respect to each other, thereby ensuring proper alignment within the illumination beam. ~'he optics of the read-write module further adjust and separate the individual write, 15 read and autofo~us beams within the illumination beam to pxovide, accuracy arad efficiency in archiving and retrieving data at high rates.
i s;;:;;-A,,,. WC7 93/22765 ~ ~ P~''f/i1~93/036fl2 a ERIEF DE~CRIPTTOhI OF ~I~E DRAWINGS
A more complete understanding of the optical tape , recarder of the present invention may be had by reference to the following Detailed Description in conjunction with the accompanying Drawings wherein:
FIGURE l illustrates an optical tape recorder system according to the present invention;
FIGURE 2 is a schematic diagram of the read°write module for the aptical tape recorder of FIGU~tE 1 showing ~.C7 the spatial combination of the multiple write, read and autofocus beams into a mufti°beam illumination beam;
FIGURE 3A is a. schematic diagram of a single polarization embodiment of the write beam s~urce for the read-write module shown in FIGURE 2; ,.~
1~ FIGURE 3B i~ a schematic diagram of a multi°
polarizati~n embodiment of the write beam source for the read-wra.te module- shown in FIGURE 2 FIGURE 4 i.s a schematic diagram of the scanning transm.issive polygon of the read~write head fox the optical 20 tape recordex shown in FIGURE 1 showing the displacement and translation of the mufti-beam illumination beam c~mprisad o'f the multiple reed, write and autofocus beams ;
F"IGU~tE 5A iilustra~es the lens wheel of the read-write p~~ad shown in FTGUR~ 1.:
,. , , . :'. z~ . ...... ..... .. ,. . ... .... . ,.. .. .. ~, ~.~ . . .;:.: . . . .
_ .

i~i FIGURE 5B is a close-up illustration of a portion of the lens wheel as in FIGt3R.E 5A showing the synchronized paths of movement of the translated illumination beam and lenses on the rotating lens wheel; ' FIGT1RE 5C illustrates the field of view of one lens of the ens wheel wherein tk~e multiple write, read ands autofocu,s beams of the m~alti-beam illumination beam are focused on the recording media along ~ data trace.;
FIGURE 5D illustrates the spacing between adjacent to data tracks in the data trace and the spacing between adjacent data marks i~ each data track;
FIGU~tE 6 is a cross ectional view of a unitary lens wheel FIGtJR~ 7 is a sch~anatic diagram of the recorder shown ~n FIGL?RE 1 including a pair o~ opposed beam expanders positioned on opposite sides of the scanning transmissive ~rol~gon ' ira tie read-write head of the present a.z~ention FIGU~ ~ ~:s a s~hemat2c diagram of the mead beam source and x°ead' array detadtor for the read-write module shown iri FIGU~ 2 ;
FIGURE 9 is a schematid diagraun of the autofdcus beam s'ousce and autof~cu~ ear~r detector for the reed~w~ite module slaowr~ in F"IGU~t7E ~
F'~G10 l.llilstX'a~Ea the astlgmatlC f~GiI,S- error correcta.on geometry utilized by the autofocus error ~ t .-r; 9~I~ 93122765 PCT/U593I03602 ..,;::..:, ~~ ,.;
w ~ ...
9 s detector shown in FIGURE ~ to detect focusing errors in the optical tape recorder shown in FIGURE 1;
FIGURE 11.~ illustrates one embodiment of the optics for the autofocus system included in the optical tape recorder of FIGURE 1;
FIGURE 11~ illustrates another embodiment of the optics for the autdfocus system included in the optical tape recorder of FTGURE 1; and FIGURE 11C illustrates still another embodiment of the 20 optics for the autnfocus system included in the optical tape recorder ~f FIGURE 1.

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WCD 93/2Z76S ,. . . P~TlU~93/0 2 V:. ~: , - to -DETAILED DESCRIPTION OF' THE D1~AWINGS
Referring now to FIGURE 1, there is shown a schematic diagram of an optical tape recorder 100 according to the present invention. The recorder 100 comprises a read-write module 102 outputting an mufti-beam illumination beam 104 and a read-write head 106 for focusing the mufti-bean illizmir~ation be~xn an a recording media 108 that is sensitive to light: Th.e mufti-beam illumination beam 104 may include either ~r both a write beam and a read bean:
The naultz-beam iliuaiin~tion beam 104 may also include other beams, such as an autofocus beam, combined with the'read and Barite beaza as needed to perform the desired functions of t3ae recorder 200. As will be discussed below, the read°
write module 102 includes light s~urces and optics (see 1S F~G~~~ 2,. 3A, 3B, 8 and 9) fir generating and combining the included multi.~channe~. write;'r~ad and autofocus beams into the a~ulti-beam illumination beam 104:
~'or purpases of either writing data to or reading data from the recording media 108, the mufti-beam illumination beam 1.f34 ~utput by the r~ad-~write module 102 is directed t~~ra~d t3ae read-writs head 1.06 comprised of a synchronized sc~nn~.ng transmissive.polygon 110 and rotating lens wheel' 112. The scanning transmissive polygon 110' is rotated about ~n axis of rotation 1~:3 in the direction indicated by arrow x.14 by a motor 116 turning a shaft 118 mounted to the °

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polygon. The lens wheel 112 is rotated about its axis of rotation 120, in the direction indicated by arrow 122, by a motor 124 turning a shaft 126 mounted to the lens wheel.
The polygon 110 and lens wheel 112 of the read-write head function in combination to accurately focus and scan the mufti-beam illumination beam 104 across the recording media 108 to provide; in a manner to be described, a multiple data track data trace.
Conventional optical storage devices include only a l0 single write beam that is focused and scanned across the recording media by a read-write head to record the data as a fine optical pattern, commonly referred to as a data track, comprised of a single line (channel) of closely spaced, microscopic dots (data marks). To increase the record and read data rates significantly over the rates provided by the conv~ntiohal sing~.e channel system, the read--write module 102 of the present invention - outputs a mufti-beam illumination beam 1.04 having a plurality of write b~a~s combined together. This illumination bean 1oa is f~cused arad scanned across the recording a~aedia 108 dy the read~write head 1o6 to record the data in a fine optical pattern (data trace) comprised of multiple da~.a tracks (channel,s) of closely spaced, microscopic dots (lots ma~,k~) a~ will be described in more detail with respect to ~S ~; gGS 5G and 5I?. ~y enabling the recorder loo of the W~ 93122765 PCT/US93/~~~..~2 ~.
~~~~ - lz -present invention to record multiple data tracks in each i data Mace scanned across the recording media, the rate for archiving and retrieving data is significantly increased over conventional single channel recorders (by at least a factor of n where n equals the number data tracks recorded in each data trace).
Referring now to ~IGUR~ 2, there is shown a schematic di~g~"am of the read°write module 102 for the aptical rec~~der lOt? og the present invention. The mufti-beam Zo illumination beam 104 output by the read-write module 102 comprises a plurality of spatially combined beams, including a plurality of coZl,ixnated write beams 128, a dollimated read beam 130 and a collimated autofocus beam ~ .
x,32, each collimated write beam 128 is output by a write 35 beam source 134 (see FIGU~S 3A and 38) amplitude modulated f,~ a p~edeteranzn~d p~artion of the data to be recorded. The plurality of write ~ beau soux°ces and means 135 for madulat~:ng the sources' in r~sp~anse t~ the predetermined porn~n of the data to be recorded comprise a write sub-2a ~ module 136 f~r the read--w~~ae module I~2. The collimated re~c3 beam 1~0: arid cc~7.linated autofocus beam 132 are ;similarly ,;output froze a read beam source and! an autofocus beam S~u~Ce (nsat showru, see F~CGLTRES 8 and 9) 'included in a read sub~znodule 138 and autofocus sub-module 1~0, 25 respectively, for the read-write module 102.
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~~193/227~5 . . r P~ d'llJS93I03602 2~.~32~
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The read°write module 1.02 further includes spatial combining optics for combining the plurality of write beams 128, read beam 130 and autofocus beam 132 to form the mufti-beam illumination beam 104 . The co7 ~ ; m~~rA~ ~,oa~,e (128, 130 and 132) output by the write, read and autofocus sub-modules (136, 138 and 140, respectively) are reflected by a mufti~pane, layered reflector 142 having a plurality of offset, layered pane mirrors 144. The beams reflected by the layered reflector 142 are further reflected by a single pane mirror 146. The angles of reflection for the panes of the layered reflector 142 and the single pane mirror 246 are chosen to deflect and spatially combine the ref3,~cted plurality of write beams 128, read beam 130 and autofocus beam 132 to converge at a point 148. A two lens system 150, comprised of an objective lens 150a positioned at the point 148 and a collimating hens 150b, pro~acts the mufti-~aea~ illuminate~n beam 7.04, ~ comprised of the spatially combined write beams 128, read beam 130 and autgfocus beam Z32, from the read-write module 1.02.
2 ~ Referring noxa to FTGIJR~ 3A, there is shown a sche~aatic diagram of a single-polarization embodiment of the y~rite beam source 234 utilized in the write Bulb-module 136 of the read-write moeiule 1.~2. A laser diode ~ 152 of a redetermined p polari~at~.on and wavelength outputs light that is collimated b a le s y n 154 a.nto a collimated wrote i z ~VCD 93/22765 ~ c~ P~.'Tf LJS931036~2 i4 ~ i beam 128. The write beam 128, as output from the write beam source 134 , is spatially combined with the write beams output from the other write beam sources 134(n) of the write sub--module 136, the read beam 130 and the autofocus beam 132. The position of the write beam 128, as output from the write beam source 134, within the multi~beam illumination beam 104 is circularized by an anamorphic prism pair 158, translated by an adjustable di placement plate 156 and painted by an . adjustable risley prism pair 159 to accurately position and orient the beam with respect to the other included beams (read, write and autofocus) to ensure proper alignment and separation of the multiple beams within the multi~beam illumination beam.
Referring now to FIG(TRE 3~, there is shown a schematic da.agran~ view of a multi-polarization embodiment of the write beam source x.34' utilized in tie write sub-module 136 ~f the read~write module 102. The multi~polarization em~odim~n~ of the write beam source 134' utilizes a dielectric polari.zer 160 (that through transmits s.~
polara:~~d light anrl reflects p-polarized light) to combine an s~polarized collimated wrat~ beam 162 channel with a p--~?o~.~rized ,,c~ll~;~ated write bean 164 channel emitted by laser diodes 152 of nearly equal wavelength ~to output a do~:bine~ polarizati~n collimated write beam 128' . With the polar~.zat~.on combined write beam source 134' the output ' s ..>' , . > -~, , .~ .
.. 1.
. . > ., ..~..
a.

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Y

V~~ 93122765 ~ ~ ~ -~.y ~ PCT/IJS93/03602 C' ° 15 -power of the write beam 128' is significantly increased.
Each polarization channel utilizes an anamorphic prism pair ' 158 to circularize the beam, an adjustable displacement .
plate 156 for translating the beam and an adjustable risley prism pair 159 for pointing the beam to accurately position the s- and p-polarized laeams, 162 and 164, respectively, at the dielectzic pola~°i~er 160. The displaceanent plate 156 and risley prism pair 159 also function to accurately po~~a~.on and arien~t the write beam 128', as output by the write beam source 13 4 ' , with respect to the other . write beams 128', read beam 130 and autofocus beam 132 to ensure p~opeg alignment and separation within the mufti-beam a~.l~xnination beam x.04.
As h~wn in FIGUIRE 1; the mufti-beam illumination beam 1.04, including the multiple collimated write beams 128 emitted from the read=writs module 102, is directed toward the 'scanning txansm~.ssive polygon 110 of the mead-write head 1~6. Referring now to FIGURE 4, there is shown a sch~ma°tic diagram of the scanning trans~i~sive polygon 110.
T.t~e ppl,yg~n 110 is c~mprised o~ a puce of optical quality transparent ma~,erial having an even number ~f sides 166 ~r~a~~ed in''oPpo~ed parallel pairs. The polygon llo is pcasiti~ned ~o receive the mu3.t~-beam illumination beam l04 Q that the beam is transmitted through th~ polygon and r~~~sct~d by one of tie op~aosed pairs of parallel sides ;:,._ .,, .~.: ..... .. . . ,_ ,.,: . . :; . ,.,.. , . »., ,:.... : : .;. .
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'WC3 93J22765 PCT/US93/03602 ', - 16 - r 166. The refracted beam is thus displaced without changing the direction of (i.e., parallel to) the callimated beam 104 received by and transmitted through the polygon 110.

Rotation of the polygon 110 about axis 113 (in the direction shown by arrow 114) causes the thraugh transmitted and displaced mufti-beam illumination beam 104 to translate and repeatedly scan, in the direction indicated by arxow ~16~; along a linear path: 170 (shown also in detail as a solid line in FIGURE 5~) . The displaced mufti-beat illumination beam 104 will scan, as the polygon 110 rotates, along path 170 from a first position, ge~~rally indichted by the output beam'172 for the solid link p~lygon, to a e~or~d pdsiti.on, ~enerall~ indicated by the output beam 174 for the dashed line polyg~n.' One scan of the beam along the path 170 occurs for each ~pposed pair of -parallel sides x.66 refracting the through transmitted mult,i-beam illumination beam 104 as the polygon 110 ,,.
:rotates::

Re~er~a,ng again to FIGURE 1, the through transmitted and'da.splaced scanning mufti-beam illumin~taon beam 104 is directed toward the rotating lens wheel 112. Referring nom ' ~ to FIGURE SA, there is' shown an illustration of the lens ' wheel 112 of the present invention. The lens wheel 11~ has s a disk shape and compra,ses a plurality of individual Lenses 176 positioned with equal spacing about the circumference ~CJ~ 9/22765 P~lUS93/d~3602 of the disc. The individual lenses 176 successively receive and focus the mufti-beam illumination beam 104 onto the recording media 108. The lens wheel is preferably a unitarily formed disk-shaped piece of optical quality material having the plurality of lenses 176 precision molded or diamond point turned therein. Each lens 176 array alternat~,vely be manufactured individually, separate and apart from the lens wheel 112; and inserted and secured within a plurality of openings forzaed about the c~.rcu~nference of the lens wheel disc. Separate manufacture .
and installation of indiv,idua~. lenses 176 is not preferred, h~wever, as ~.h~ unitary lens wheel 1I2 described above more accurately performs ane~ may be manufactured less ..
~xpensa.vely and rep~od~acecl more consistently.
~s th~,lens wheel 112 is rotated about its center 120 by the,motor 1~4 (FI~tTR~ 1), successive individual lenses x76 about the circumference of the wheel m~mentarily ~eee~;~e and focus the mufti-beam i.lluxnination beam 104 on 'the recording meeiia 108. F~cusing of the mufti-beam illuz~i~at3can laeam 104 by ~ dens 176 occurs only when the lens momentara.ly moves thr~uc~h an active area 178 on the ~.~ns'wheel 112 generally correspcanding to the 1~cation of the recording ~aedia 108 and the area where the ~nulti-beam illu~aiz~ation beam 1.0~ illuminates the lens wheel. Rotation of the lens wheel 112 in the direction shown by arrow 122 .. '. ;...,. . , ....... , .....,.. . , ..... . ;....: ." .... . -.....~ ;
~.y: ~.;'.;.... ,. S ....~. ~ ., .. , , . ......, i ~f'~ 93/22765 ~ PCT/tJS93/036U2 ~13432~ °'~ ~
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~, , 18 _ causes successive individual lenses 176 to follow an arcuate path 180 (shown in detail as a broken line in FIG~TI~E SE) through the active area 1.78. The path 180 consists of a portion of the circumferential path within ' the active area 178 f~llowed by the center of each lens 176 as the lens wheel 112 rotates. Each lens 176 passing through the active area 178 receives and focuses the incident mufti-beam illumination beam 304 onto the retarding media 108 to scan a data trace 182 across the width of the media. With movement of the recording media 1(7g in a direction (shown by arrow 184) Perpendicular to the direction of the- race 182 and rotation of the lens wh~e1 112 (shown by arrow 122), successive lenses 176 bet~me active to scan out successive para17.e1 and adjacent data traces across tlae recording media.

The linear path 170 followed '~y the scanning mufti-~ea~ illumination beam 104 amd arcuate path 180 followed by each ~.ens 1;76 on the routing ~.ens wheel 112 through the , acta:ve ~:re~ 178 are shown superimposed over each other in FIT 5F1, mhe muftibeam illumination beam 1Q4 (shown ill.umi~ating a circular area 1~6 ~n the lens wheel that is lightly larger thin the diameter of a lens v1~76y.

illuminates a portion of the active area 178, while scanning Tong pith 17C~, between the broken lines 188.

Full illu~nanation of each successive lens I76 moving along .: ,. . ,,.. .. , . ..., . ... . . --,., >,., .:~: , ~..~.~ .... : ., v: v~
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,_ WC193/2z7G5 ~ P~,'T/US93103602 ~:,.~, . . , path 180 by the scanning of the multi-beam illumination beam 104 along path 170 to scan successive parallel data traces 182 first requires treat the position of the paths be substantially aligned (as shown in FIGURE 5B). A slight deviation between the paths as Shawn caused by the lens path 180 being'arcuate and the scan path 170 being linear i.s permissible due to the size of the area between lines 188 that will be illuminated.
Referring now o FIGURES 1, 4, 5A and 5E, full l0 illumination of each successive lens 176 further requires that the movement of each scan of the multi-beam illumination beam 104 along path 170 be synchronized to cgincide with the movement of each successive lens along path x;80 through the active area 178. With synchronizaa~.on, the circular area 186 illuminated on the ~:ens wheel 112'will fully illuminate each lens 176 as the lens waves through the active area 17f thereby -achieving the smallest possible bit diameter on the recording media 108 a~ p~ssible fox° each of the anultiple data tracks reco~d~d in sash data tr~.ce 182 a~ will be described. To achieve full illumination, the actuation of the motors 116 anc~ 124 for ; the polygon 110 and lens wheel 112, respectively, are ~ontr~lled for synchronization, as generally indic~t~d ~t 19a, such that one scan of the ~~ mufti--beam illumination beam 104 along linear path 1.70 will i~V~ 93/22765 , , PCf/U~93J036~','t ~':~-' , i.

occur for and correspond with the movement of each lens 176 a.
through the active area 1.78 along arcuate path 180.
Referring now to FIGURE 5C, there is shown the field of view 192 of the mufti-beam illumination beam 104 as focused on the recording media 108 by a lens 176 of the .lens wheel 112. As discussed above with respect to FIGURE
2, in order to provide the increased archive and retrieval data rates for the optical recorder 100 of the present invention, the mufti-beam: illumin~ti~n beam 104 includes a mul~i-ch~.nnel write bean 128 output by the n write sources 134(n) in the wrzte sub-module 136. Thus, each data trace x.82 on the rec~rdi.ng media 108 will be comprised of n channe~a of rec~rded data. Each channel of data is recorded on the recording media 108 as a data track 194 (see also FIGURE 5D) within the data trace 182. The posita.on of each write beam 128 within the mufti-beam i~:lmnination ~aeaan 104 is controlled by the pointing and trans~,ati.ng optics (see FTGURES 3~ and 3B) such that the multipi.e channels ire separated from each other to 2~ i.llu~inate separate and d:isti.x~~t write spots 195 within the field ~f view 192 as f~cu~ed on the recording media 108.
As .oho, there arm thiY°ty-two write spots corresponding to the n = 32 write ~ou~ces 134 and data channels in the write s~-~~dule 136. .The permissihle number of write sources 25 134(n) inc~.~aded in the optical recorder 300 is limited by _ .. ... " ....: , :.. _._.. . .:,..,, ..:; .., :, ::: ..:::~ :::~ .. :.. v ~~
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., t.
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: .. ,: . . .. ;. ~. . _ .. . .. .

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- 21 - , the chosen size of the field of view 192 and the accuracy of the spatial combining optics shown in FIGURE 2.
Referring now to FIGURE 5D, there is illustrated a k piece of recording media 108, within a portion of a data ' track 182 as shown in FIGURE 5C, illustrating the marking of the light sensitive media by the multiple write beams 128 of the fodused raulti-beam illumination beam 104 to recprd the data. portions of two data tracks 194 within a data trace 182 are shown: The spacing between the centers Z0 of adjacent data ti°acks 194 in a data trace 182 is ~ppraximately one and a half microns with the centers of adjacent data max°ks 196 within a data track 194 separated bY ~~proximately one micron. Referring again to FIGURES
3~, 3~ and SG, the displacement plate 156 and risley prism .
~5 Pa~.r 158 are ~djus~ed for each write beam source 134 to .
transl~t~ and point each write beaan 128 for accurate po~gt~;oning and arien~ation of the plurality of collimated be~~as w~.th respect ~o each other within the multi-beam illt~tin~tion be~a~ 104 a~ projected within the field of vie~r 20 192 can the recording media 10~. Froper translation and pointing ensures an ~pproxi~~te one and a half micron ~p~~ing between adjacent data'tracks 194. The modulation v.
of the write sources 134 by the data to be recorded is also ~'~~Wated, i~a acc~rdance with the predetermined rotational 2 5 velocity of the lens wheel 112, to maintain proper one W~ 93J2z7~55 PCT/~JS9310360 ..f;
~~.34325 i micron (approximate) spacing between adjacent data marks 7.96 in a data track 194. Adjustment of the spacing between adj scent data tracks 194 and adj scent data marks 196 in the manner indicated maximises data storage density while maintaining system data recording and recovery accuracy.
Referring now to FIGURES 1-5D, to record data on the recording media 108, the intensity of the collimated write beams 128 output by the write sub-module 136 is adjusted such that the beam wi3l mark the Light sensitive media.
each write beam 128 is axaplitud~ modulated (on/off) according to the means 135 by a predetermined portion of the data, carried by a data signal, to be recorded. The plurality of write beams 128 are spatially combined within the read-write m~dtale 1.02 to form the mufti-beam illumination beam 104, translated by the scanning polygon 110 and focused on the media by the lenses 176 of the rotating lens wheel. 112 to scan multiple data tracks 194 caathir~ ~ach,data trace 182. Translation of the media in a direction (shown' by arraw 184) perpendicular to the rotation of the lens wheel 112 allows a plurality of data traces 182 to be rec~rded adjacent to each other on the media lOS .
For e~cample, the lens wheel 112 may include twelve lenses 176 and be rotated at 6,500 revolutions per minute.
This results ~.n a scan of 1, 300 lenses 176 across a 3/4 .. .: ". .. .. . , . . , :. . ; ; : v 'r . .; ,., . . ; . ,:
. . . .; ~ . ~ ' iN~ 13J22765 P~I'J~1S93J03502 f:;~:~

inch wide tape 108 every second. Assuming a one micron spacing between adjacent marks 19~, if one channel (data track 194) of data is written per data trace 182 (as in the prior art conventional optical recorder), 19,000 unformatted data samples will be written across the tape media 108 in each data track. This.is equivalent to an unformatted twenty-four megabit per secanr3 archive rate.
With the mu3ti~channel recording capability of the optical recorder l00 of the present invention, a thirty-two (n=32) channel (data track 194) per data trace 282 write beam 128(n) (as shown in FIGURE 5C) is provided resulting in an u~,~e~atted archive rite in excess of 760 megabits per second. This a~cl~iv~ rate wily easily satisfy the design goal of a X00 megabyte per second archive rate rec~uuired for handling current and future data recording needs.
g~ef~rring now to F'IGU~ 6, there is shown a cross-seed.ona.l view of the uxrita~y lens wheel 112 ~ hawing a plurality oaf precision molded or diamond point turned o lenses 176 p~siti~n~d abo~~ the circumference of a disk shaped body. ~Yae preferred optical lens desi n for each q lens 176 in the lens wheel 112 is a piano-convex singlet ha~rirag an aspher~:c figure on the convex side 198. The use of a piano surface 200 in conjunction with a convex powered surface 198 prova.des for a less complex lens design by removing the alignment tolerances associated with centering i~dJ 93/22765 PC,'TfU~93/~36~2 ~~
.'~

two powered surfaces to ether g (as in a double-convex or concave-convex design). The piano-convex design is further preferred because the design minimizes the wedge between included optical surfaces in the lens and the piano surface provides a useful reference flat. Thus, the piano-convex design using a convex surface 198 coupled to a piano surface 200 provides for easier, less expensive and more efficient fabrication, testing and assembly of the lens wheel 112.
With a lens design where one surface (the aspheric surface 198) prov~.des the majority of the focusing power, an optical material with a refractive index exceeding 2.25 (far example, "Gl:eartran°' zinc sulfide) is preferably used for fabricata.ng each lens 176. In the preferred embodiment, the ~ntir~ lens wheel 112 (as shown in FTGURE
6) , including the disc support structure and the individual lenses, i~ un.itarily ,fabricated . from the highly refractive ~pt.ical, duality material usa:ng precision molding or diamond ppint turning techna:ques. Precision molding of the indiva.ciual lenses 176 with the disk substrate of the lens wheel f~~s ~ unitary lens wheel 112 possessing the advantages Qf ; being consistently accurate,' easily reproducible .and interchangeable. In the alternative, after ~:ndividual fabrication of each lens 176 from the ~5 preferred optical material, the lenses are inserted and ' . _ . . . . , ... : -: . .., . , ;. .; ..... .. ; .; .:, _ . : .: . ::--. : -. : ~ . .; . ; . ; . . ; .
.f ". . . . : . . ,. , , .. _ . . . . . . , wc~ ~~rzz76~ P~ri~s93io3~oa f secured in one of a plurality of openings around the c~.rcumference of the disk-shaped lens wheel 112 in accordance with the teachings of~the prior art.
i As mentioned above, the lens wheel 112 used in the read-write heaa~ 106 has a disk shape unitarily formed from an optical quality material using precision molding or diamond point turning techniques. Tf precision molding techniques are employed; a master lens wheel that is .
essentially a negati~re of the optacal surface desired on the dens wheel is used to form the lens wheel. To .
fabricate the lens w~.eel la2 from. the master, a~ high c~ual.aty optical polymer or specially formulated glass is precision molded a.n ~cco~rdance with the shape of the master. In the altegnative; a flat high quality optical substrate serves as a base for deposition of a thin epoxy layer, with the mater melding the lenses into the epoxy to ~abriaa~e the c~h~el.
I f .refractwe optics are to be used for each individual lens 176 on the lens wheel 112, the master is 2 ~ created using ccanv~ntional diamond turning and polishing techniques. hf di:ffractive optics are to be used, either li~h~graphy, oz° dli~mond turning are used t~ create the ,.
master. Diffractiv~ lenses:~x°e typically modelled and fabricht~d as e~.thez° ki.noforms rar binary lenses. A fresnel 25 lens ~:s a specific tlrpe ~~ kinoform. The smooth surfaces ... . >. .. . . ~ ; , . . .;, . , ..: ...
~.... . . . . .

!~'~ 93122765 PCT/US~310~ ~2 b~~.~43~~ w of kinoforms are apprr~ximated using flat surfaces and step functions (binary optics). Flat surface approximated _ kinoforms are manufactured using diamond turning techniques. binary optics are manufactured using either photolithography or electron beam lithography by iteratively masking and etching a substrate. Once the lens type (refractive or diffractivey and manufacturing method are determined, the master is fabricated according to the preferred method: A plurality of lens wheels are then 1p manufactured from the master using precision molding with the resulting lens wheels being identical, interchangeable and functional over a broad wavelength range. the lenses wil l also have substantially identical back focal distances, aind and aberrations due to lens design are 1.5 consistently present across all lenses on the wheel.
Fte~erring again to FIGURE 4, for several mechanical and optical per~ox~nance optixnizati.on reasons discussed below, the nu~;ber of opp~sed pairs of sides 165 for the ~olyg~ra 1I0 shoulr~ be maximised (as a function of resulting 20 a~ncrease~ in ~aanufacturing: complexity and cost). One benefit obtained from increasing the number of opposed i sides 1,66 as , that the polygon 1.10 more closely resembles a disk thereby ~ecreacing .~h~ effects of windage as the polygon rotates. F'urther~ore; an increase in the number of 25 opposed sides lfi~ decreases the rotational velocity of the .
b~'~ 93122765 PC'd'/~JS93/~D36~2 y.

polygon 110 required for a fixed rotational speed of the t i lens wheel 112. This is important because high rotational velocities for the polygon 110 load the motor 116 and ' induce optical barefrangence in some optical materials chosen for fabrication of the polygon. Finally, increasing the number of :opposed sides 16G of the polygon 110 decreases the maximum angle s~f incidence of the multi-beam illumination beam 1Q4: This reduces variations in fresnel refledtion coefficien~.s and enables the use of both s- and p-polarized light for the multi-beam illumination beam 104 to increase recorder bandwidth (see, for example, the mult~.-polarization writs beam in FIGiJRE 3H) Referring now to- FIGURE 7, the read-write head 106 for the optical tape recorder 1.n0 of the present in~r~:ntion (see FIGURE 1) is shown f~,rtlaer a.ncluding a gair of beam expanders 202 positioned along the multi~beam iZlur~ination beam 104 on mach side ~f the'scannir~g trans~issive polygon x..10 s H~~m expander 202a is l.c~cated between the scanning polygon 110 and the read-write module I02: Heam expander 2c~ 202b is ,located 'between the scanning polygon 310 and the lens wheel x:1.2,' The use of a pair of beam expanders 202 provides a ~demaga~ifi:catiort-aaagni.fication system around the poiyg~~ 1.1.~ that nax~ro~s the diameter of the mufti-beam illu~inat~.on be~~ 1,~4 incident on and transmitted through .: . ,._~. -.. : - . .. ,, ,, , - _ . ,-,..: v, ;.- ;-.v .. . ':.' : , , , ,;
.r ". ,":. , . ... ,.,. ... .:.. ... ....
.. ,... ., " ,. . .. . : ...:.. ,:. . . . . .

~V~ 93/22765 - P~T/US93/036~2 ;::.
:.
. ...
~,~~ 4~2 .. - 28 -.., the polygon and expands the diameter of the beam output from the polygon.
With a smaller diameter multi-beam illumination beam ~ .:;
104 transmitted through the polygon, the size and shape of ~ ;
the polygon may be scaled as desired in accordance with manufacturing complexity and cost concerns while realizing the mechanical and optical performance benefits of an increased number of sides 166 as discussed above. An additional benefit from scaling the size of the polygon 110 is a less stringent manufacturing specification for the parallelism of opposing sides 166 causing a corresponding decrease ~.n polygon manufacturing costs. Furthermore, by narrowing the diameter of the mufti-beam illumination beam 104 transmitted through the scanning polygon 110, the duty 7.5 cycle of the system is increased.
Referring now to FIGURE 8, there is shown a schematic view of the read sub-module 138 within the read-write ~odula 102. The read sub°-module includes a read source 204 (similar to the ~rrite source 134 shown in FI~UR~ 3A) for outputting a collimated read beam 130. The read source 204 includes an anam~rphic prism pair 158, a displacement plate 156 and risley'p~ism pair 159 for shaping, translating and pointing the read beam 130 output by a laser diode 154 and collimated by a lens 154. In particular, the anamorphic prism pair 158 shapes the read beam 130 forming a ~ , r.. i .:~ ~'..~'~.. ~ . ~..., ...
t,,. , ~ "-~ ,,:;Y , ;:.,:;:, 1~~ 93J~x765 PCfJ~JS93103602 ~~,; ..n..f .. . y 2 ~ - i rectangular illumination field 246 within the field of view 192 as focused on the media 1.08 (see FIGL7RE 5Cj to ~
illuminate across the multiple data tracks 184 (channels]
of a recorded data trace x.82. The pointing and translating optics of the read source 204 also function to accurately position and orient the read beam 23~ with respect'to the mu3'~ipl~ write beams 128 and ~autof~cus beam 132 to ensure proper alignment of the multiple beats within the multi-beam illumination beam 1o4. The pblari:zation of the read ~

.
2o J
beam 1.30 is Changed by forty~five degrees by passing the beam through a quarter-wave plate 208.

Referring again to FTGUFtES 1, 2, 5C arasi 5D, the rectangular pattern 20f of the ~eadbeam 130 is scanned by the rotating lens wheel 21.2 along the length of a data trace 182 to be modulated by the data marks 156 of the mina ipl a data trac~CS 19 ~ ( channel s j therein . The mufti--channel -modulated read beam- 1.30 is reflected by- the media 1~8 back thxough the rotating lens wheel 112 and scanning' transmass~.v~ polyg~n ~.~.0 of the gead-write head 106 t~ the read: sub-module 138 of the read~write moriule '102. As shown' in FIGURE 8,'tMe p~l~rization of the modulated read beam l ~.1~0'is rotated an additional forty-five degrees (~~for a total ~f ninetqr degrees and a c~a~rage, for exa~aple, from s~

to p~p~lari~ati~nj by the quarter-wave piste 208. The m~dulated read beam 130 is then zeflected by a polarisation ~t~ 93I2z76S ~ ~ ~. PCTILJS93/03602 f ° 30 °
beam splitter 210 and imaged on a linear photodiode array 212 by a magnification system 214. The linear ph~todiode array 27.2 preferably comprises a plurality of avalanche photodiodes or PIN photodiodes that produce electrical ' signals in accordance with the mufti°channel modulation of the read beam 130 to recover each channel (data track lg4) of data scanned within each data trace 182. The multiple charnels of data arm then reassembled in proper order to recover the data signal.
7L0 ~2ef~rring now to FIGURE 9, there is shown a schematic view of the autof~cus sub°module 140 within the read-~irite module 102. The autofocus sub-module includes an autofocus so~.rce 21.6 (sa~milar to the write source 134 shown in FIGURF
3A) for outputting,a collimated autofocus beam 132. The autofoctas source 216 includes an anamorphic prism pair 158, a displacement plate 1:56 and a ri~'ey prism pair 159 for shapi.a~g; ~ransla~ing and Pointing the autofocus~ beam 132 output by a laser diode 152 and c~llimated by a lens 154.
The po.in,ting and translating optics of th.e autofocus source 216 shape the aut~focu~ beam 132 for focusing to a spot 218 see FI~U12E 5~) on ' the ~aedia 108. The painting and ~tra~slating opti;~s further function ;to accurately: position and orient the .autofocus beam 132 with respect to the mul.t~.ple s~gite k~eam~ 12~ and read beam 130 to ensure proper aliment of the multiple beams within the mufti-beam ' r, . . :: , .. . .. . ,; .: . , .,: : .. . ; . , , ; ... - ,.;. . , . . . ;: ;
. ~ ::
s ..;. ::.. ;;:: :;-:. .;. : , . ~: .. , ..- ;: .: . ; " ,,, , ,: .. ; .
... . ..

W~ 93/22755 ~ ~ ~ 3: ~ ~ ~C'I'/~JS93/036df2 t, ,r~ : F
f illumination began 104 as focused on the recording media w~ ~3rzz°~ss ~ ~ ~ pcrius~~r~3~o2 i Many autofocus techniques may be employed. For example, referring to FIGURE 10, there is shown a geometry , utilizing the autofocus detection system shown in FIGURE 9 to detect focusing errors. The distance "D" represents the distance between the write lens 176 of the lens wheel 112 and the astigmatic lens 228. The distance "fo" represents the focal length ~f the lens 176 on the lens wheel 112.
The distances "~~'° and '°fz" represent the focal lengths of the astigmatic-lens 228. The distance "d" represents the distance between th~,astiga~atic lens 228 and the guadrant detector 224 and is given by the following equation d _ 2 ( ft) ( f2) ~ (ft + gz) .
If tie distance d is set according to the above ee~uation, then the astigmatic lens 228 focuses a circular illua~anation spot on the quadrant detector 224 for the reflected autof~cus beam 132 when the error distance "err"
between'the re~c~rdi.ng media 108 and the focal plane of the write ~.ens x.76 is zexo (a.e~. the autofocus beam is focused on the'media). When the aut~f~cus beam is not focused on he recordia~g media 108; the error distance err is non-zero 'and the astic~ati.c lens 228 focuses an elliptical ~:~:luaaina~ion spot on tY~e r~uadrant detector 224.
sacra g~a~ir~nt 2 3 0 ( a. ) -2 ~ 0 ( 4 ) of the detector 2 2 4 outputs a cnrrespending signal (~1-Q4) proportional to the intensity og the fight from the ref3ected autofocus beam - x . r~o ~~~zx~ss ~ ~ ~ ~ ~ ~ ~ ~c.-rms~3~o3~oz 132 focused thereon by the astigmatic lens 228. The signals Q1-Q4 may be used to determine a focus error signal (FES) indicative of whether the mufti-beam illumination beam 104 is properly focused an the media LO8. The FES is determined in accordance with the following equation:
FES -- [(QZ + Q3) (Q2,+ Q4)] / [Q1 + Q2 + Q3 + g4].
The F'ES is output from a signal processor 232 implementing the above equation tca control the adjustment of the read-wr~ae head 106 in a manner to be described to fcacus the o mufti-bean illumination beam'on the recording media 108.
When the error distance "err" is positive (i.e., the distance between the media 108 and the write lens 176 is greater than fo);;the vertical~diameter of the elliptical illumination spot across quadrants 230(2) and 230(4) is 1S greater than the horiz~ntal diameter across quadrants 230 (1) and 230 (3) . Thus, the sigr?als Q2 and Q4 will be greater khan the signals Q1. and Q3. The FES determined by the above stated equation will therdfore be.negative. The opposite is rue when the distance between the media 108 2Q and the write lens I76 is less than fa. If the error distance "err" is zero (i.e:, the mufti-beam illumination ~eam~l0h isfocused on the media lpg); 'the,illumination~
spot on the ~xadrant detector' 224 wily be eircular and the ignals Q1°S2~ will be substantially equal to each other ddlJ 93IxZ765 PC'Tl~J~93/036#~Z
c . . ~:.::.::Y !
~,~~~~~~ 34 w ,.
(because the vertical and horizontal diameters of the spot are equal ) , resulting in an FES substantially equal to zero .
Reference is now made to FIGURES 11A-11C wherein there are shown seve~ca.l embodiments for the autofocus error correction system 234 in the read-write head 106 for the optical recorder 100. The embodiments of FIGURES 11A and 118 illustrate lens translation methods for providing autofocrxs error cc~~rectzon. The embodiment of FIGURE 11C
illustrates a media translate~n method for providing autbfocus error correction. The translation of either lens ox media for the error correction system of each embodiment is controlled by the sign (either positive or negative) of the focus error signal ( FES ) generated by the processor 2 3 2 accord,irag to the equation above in response to the signals Q1°°Q4 ou~pu~ by the quadrant detector 224 (see FIGURES J
and I O ) , ~
I~, the ea~boc3ixnent for the autofocus error correcti~n sYs~~m 234 illustrated in FIGURE 11A, a pair of autofocus lenses 236 are posata.oned in line with the mufti-beam .
illumination bean 104, including the multiple write, read end autofocus beams, between the read-write module 102 and thte sc~nnin~ tra,nsma~si~r~ polygon 3:10. A' servomotor 238' i ~ ~
adjusts (translate) the position of a first one of the au~ofocus lenses (lens 23Ca), back and forth in the direction indicated by the two-headed arrow 140, along the .:..-:, ~~ 9122765 ~ ~, ~ y ~ ~ PL'I"IU~93/03602 ,:-.,.. .. ;
. ,. ..
- 35 _ . .
Path of the mufti-beam illumination beam 104. The i translation of the autofocus lens 236a by the servomotor 238 is controlled by the sign of the focus error signal output from the autofocus sub-module 240 of the read-write module 102 such that the focus of the mufti-beam illumination beam 104 occurs at the recording media 108.
One drawback experienced with this autofocus method is the difficulty in designing the fixed autofocus lens 236b and wxite lens 176 to correct for the varying amounts of -10 spherical aberration produced by translation of the autofacus lens 236a.
pn~ way to avoid the spherical aberration drawbacks encountered w~.th the emb~diment of FIGURE 11A is to t~°anslate each write lens 17 ~ on he rotating lens wheel 15 112; as shown in the embodiment i~.lustrated in FIGURE 118.
The se~vomot~~° 238 i~ mounted on the lens wheel 1I2 and connected to t~°anslate each write lens 176 back and forth in the da.r~cti~ns indicated by the two-headed arxow 240 for focusing the mufti-~bea~ illumination beam 104 on the 20 reco~cding media 108: Trar~s~.ation ~f the write lens 176 occtars within the ~trudtux°~ of the lens wheel disk in ,response to the; sign ~f the focus error signal (FES) recei~red fr~m the autofocus sub-module 140 'of the read-write a~~dul.e 102. This ; technique; however, is not 2~ . P~'efe~'~'ed due to the increased compleacity of the servomotor Y
- ~ n S ;'. . . . .:~ ~-.:. ,..: ~.,. . . ..... . ."'. .~ ,, ' .ri.
S , ........ ." ...'..' . -. : :.; ...n ":..:. .,-....:., ~.~:.;. . . .,y.-,. .
....... ~:~ ..y.. .. ".:..., , '.:":v . ,:.:'~.,, . : '~ ,. ,'. :.:n' : , ;,:
.,.. ':. :~ ,:..v.. :. .; h,. .,.. !: ..,.., to Y 5. ..
p .. . . I ,. .,.., . . . . . .. . ,..., ..1...".u.... .,. n .... .. . ... . .. ...... , ., . .n . .... ,.. . ... .l...
w ... ,. .. . . , i w~ ~~izz'6s ~ ~~rm~g~io~soz ., °:~::,' , and lens wheel 212 required for translating each individual lens in the lens wheel.
An alternate means for avoiding both the spherical aberration servomotor actuation drawbacks described above is to translate the recording media 108 as illustrated in the embodiment of FIGLTFtE 1ZC. An air plate 242 is positioned under the moving recording media 108 on the oppesite side from the rotatang lens wheel 112. Movement of'the recording media lg8 back and forth an the directions indicated by the two-headed arrow 240 is effectuated by an array of air nozzles 244 expelling air through the air plate 242 against the underside of the media. The amount of mo~rement for the media 208 along arrow 140 is controlled not on;llr by the amount of air expelled by the air nozzles 244; but also by the amount of tension appl~.ed to the media 108 while p~s~ing over the air date 242. A control circuit 2~6 responsive to the sign of the FES output by the auto~ocus sub-module 140 adjusts the aauount of air expelled via control. line 248 and further adjusts the tension on the 2 0 med~:a 10~ , as generally indicated at 250, to props r l y ~as~tion the ~aedi:a fir focusing the rnulti~-beam illum~.nation beam 104: 4 - , Although several embodiments of the optical tape recorder og the present invention have been described in the foregoangf Detailed Description and illustrated in the F

', . ,.'.:; ~........ .~,...,, , ... ... , ... ,.. ; . ,, . .,.... ...:~,...
... , ... '~:., ~ , ., : , L .'. ,..:.. ,; ....,,. : .. ,';r.'.., ' .~;: . ,~.'.. :: :.. ,~ ~ ' ..:.:..._.... ;..~ ....,:., , ..., , ~.. .., , !'CT/US9~/03602 __ ~'~'~3/22765 '~ ~ ~ ~ '~.~ , i:,a::;: 1 accompanying Drawing, it will be understood that the a invention is not limited to the eaabodiments disclosed, but is capable of numerous rearrangements, substitutions and modifications without departing from the spirit of the inventionv

Claims (24)

CLAIMS:

1. Apparatus for optically recording and reading a data signal within a plurality of data tracks of a light sensitive recording media comprising:
first light source means for emitting a plurality of write beams;
means for modulating each write beam by a designated portion of the data signal to generate a plurality of data signal modulated write beams;
a second light source means for emitting a read beam; and a plurality of reflector panes in a layered configuration and a single pane reflective mirror, each reflector pane and said mirror having a preselected angle of reflection to deflect and spatially combine the plurality of data signal modulated write beams and the read beam into a collimated multi-channel light beam.

2. The apparatus for optically recording and reading as in claim 1 wherein the first light source means comprises a plurality of laser light emitting diodes emitting light having a predetermined frequency each having a lens for collimating the emitted light into a write beam and the second light source means comprises a laser light emitting diode emitting light having the predetermined frequency and having a lens for collimating the emitted light into the read beam.

3. The apparatus for optically recording and reading as in claim 1 further comprising:
means for shaping the read beam to illuminate on the recording media a plurality of recorded data tracks within a data trace recording the data signal, the read beam modulated by data marks within the plurality of data tracks to generate a data modulated multi-channel read beam; and means for detecting the multiple channels of the modulated multi-channel read beam to recover the recorded data signal.

4. The apparatus for optically recording and reading as in claim 3 wherein the second light source means comprises a laser light emitting diode and a lens for collimating the emitted light into the read beam.

5. Apparatus for optically recording information on a recording media, comprising:
a plurality of light source means, each outputting a write beam channel;
means for modulating each write beam channel by a predetermined portion of the information signal;
means for spatially combining the individual write beam channel output by each of the plurality of light source means into a collimated multi-channel light beam;
a rotating lens wheel having a plurality of circumferentially positioned lenses for receiving and focusing the collimated multi-channel light beam on a surface of the recording media, each lens successively following an arcuate path through an active area, said arcuate path traced by a portion of a circular path followed by each lens as the lens wheel rotates;
means for scanning the collimated multi-channel light beam, such that the beam scans along a linear path substantially aligned with and corresponding to the arcuate path followed by lenses in the rotating lens wheel; and means for synchronizing the scanning of the collimated multi-channel light beam with the rotation of the lens wheel such that the movement of each scan of the beam along the linear path coincides with the movement of each successive lens along the arcuate path.

6. The apparatus for optically recording information as in claim 5 wherein each light source means further comprises a laser emitting light of a predetermined frequency and intensity for creating a mark on the recording media;
means for forming the laser emitted light into a write beam channel.

7. The apparatus for optically recording information as in claim 5 further comprising a means for rotating the lens wheel about an axis so that each lens momentarily receives and focuses the collimated multi-channel light beam to scan a plurality of data tracks across the recording media in each data trace, each data track corresponding to one of the plurality of write beam channels within the collimated mufti-channel light beam.

8. The apparatus for optically recording information as in claim 5 wherein the means for scanning comprises:
a transmissive polygon having an axis of rotation and a plurality of opposed pairs of sides for refracting and displacing in a parallel manner the collimated multi-channel light beam incident on and transmitted through the polygon; and drive means for rotating the polygon about the axis of rotation and causing the through transmitted and displaced collimated multi-channel light beam to be refracted and displaced by the opposed pairs of sides and thereby repeatedly scan along the recording media.

9. The apparatus for optically recording information as in claim 5 further comprising:
light source means for outputting an autofocus beam channel to be spatially combined with the plurality of write beam channels into the collimated multi-channel light beam, the autofocus beam channel focused on and scanned across the media and reflected thereby;
means for focusing the reflected autofocus beam to a spot;
detector means for detecting the shape of the focused spot;
and means for determining from the detected shape of the focused spot whether the collimated multi-channel light beam is properly focused on the recording media and outputting a signal indicative thereof.

10. The apparatus for optically recording information as in claim 9 further comprising:
autofocusing means responsive to the signal output by the means for determining for adjusting the focus of the collimated multi-channel light beam on the recording media.

11. The apparatus for optically recording information as in claim 5 wherein the collimated multi-channel light beam further includes a single read beam channel and further comprises:
a light source means for outputting the single read beam channel to be spatially combined with the plurality of write beam channels into the collimated multi-channel light beam, the single read beam channel focused on and scanned across the recording media along each data trace and across each of the plurality of data tracks within the data trace by the means for scanning, said single read beam further being modulated by data marks stored in the plurality of data tracks within each scanned data trace and reflected therefrom; and an arrayed photo detector for demodulating the modulated and reflected read beam channel to recover the information signal from plurality data tracks of recorded data in each data trace.

12. The apparatus for optically recording information as in claim 11 wherein the light source means for the single read beam channel comprises:
a laser source emitting light of a predetermined frequency and intensity for illuminating the recording media;

means for forming the emitted light into a single read beam channel; and means for shaping the single read beam channel to illuminate a rectangular area on the recording media across the plurality of data tracks within each scanned data trace.

13. Apparatus for optically recording a data signal on a recording media, comprising:
first light source means outputting a plurality of write beams each modulated by a designated portion of a data signal;
means for spatially combining each of the plurality of data signal modulated write beams into a collimated multi-beam light beam;
means for scanning the collimated multi-beam light beam such that the beam repetitively scans across an active area along a linear first path from a first point to a second point;
means for focusing the collimated multi-beam light beam on a recording media;
means for repetitively translating the means for focusing across the active area along an arcuate second path from a third point to a fourth point, wherein the first and second paths are substantially aligned with each other; and means for synchronizing each scan of the collimated multi-beam light beam along the first path to coincide with each translation of the means for focusing along the second path to focus and trace the collimated multi-beam light beam across the recording media along a data trace, each write beam of the collimated multi-beam light beam recording a separate data track within each data trace.

14. The apparatus for optically recording as in claim 13 wherein the first light source means comprises:
a plurality of lasers each emitting light having a predetermined frequency and intensity for marking the recording media:
means for forming the light emitted from each laser into a separate write beam;
means for pointing and translating each write beam with respect to the plurality of other write beams within the multi-channel light beam to position each write beam to record separated data tracks within each data trace scanned across the recording media.

15. The apparatus for optically recording as in claim 13 wherein the means for scanning comprises:
a transmissive polygon having an axis of rotation and a plurality of opposed pairs of sides for refracting and displacing the multi-beam light beam as transmitted through the polygon; and drive means for rotating the polygon about the axis of rotation thereby causing the through transmitted multi-beam light beam to repeatedly scan along the linear first path.

16. The apparatus for optically recording as in claim 13 wherein the means for focusing the collimated multi-beam light beam comprises a plurality of lenses.

17. The apparatus for optically recording as in claim 16 wherein the means for repetitively translating the means for focusing comprises:
a lens wheel having a disk shape wherein the plurality of lenses are positioned with equal spacing about the circumference of the disk; and means for rotating the lens wheel about an axis so that each lens momentarily moves through the active area along the arcuate second path to focus and scan the collimated multi-beam light beam across the recording media along a data trace.

18. The apparatus for optically recording as in claim 13 further including:
second light source means outputting a single read beam that is combined with the plurality of write beams into the collimated multi-beam light beam by the means for spatially combining, the single read beam moved to scan across the recording media to illuminate the plurality of data tracks within each recorded data trace, the read beam modulated by data marks within the plurality of data tracks to generate a modulated, multi-channel read beam, each channel within the single read beam corresponding to a data track within each data trace; and means for detecting the modulated, multi-channel read beam and generating an output data signal corresponding thereto to recover the recorded data signal.

19. The apparatus for optically recording as in claim 18 wherein the second light source means comprises:

a laster emitting light having a predetermined frequency and intensity for illuminating the recording media;
means for forming the emitted light into a single read beam;
means for shaping the single read beam to illuminate across the plurality of data tracks within a data trace; and means for pointing and translating the single read beam with respect to the plurality of write beams to position and separate the read beam within the collimated multi-beam light beam.

20. The apparatus for optically recording as in claim 13 further including autofocus means comprising:
third light source means outputting an autofocus beam that is combined with the plurality of write beams to form the collimated multi-beam light beam by the means for spatially combining, wherein the autofocus beam is traced across the recording media and reflected therefrom;
means for focusing the reflected autofocus beam to a spot on a detector having means for identifying the shape of the spot of the reflected autofocus beams; and means for determining from the identified shape of the spot whether the collimated multi-beam light beam is properly focused on the recording media and outputting an autofocus control signal indicative thereof.

21. Apparatus for optically recording data on and recovering data from a recording media sensitive to light, comprising:

a plurality of first light sources outputting a corresponding plurality of modulated write beams, each write beam modulated by a designated portion of a data signal;
a second light source outputting a read beam;
means for combining the modulated write beams output by the plurality of first light sources and the read beam output by the second light source into a collimated multi-beam illumination beam;
a transmissive polygon having a first axis of rotation and a plurality of opposed pairs of sides for refracting and displacing the collimated multi-beam illumination beam as transmitted through the polygon, said transmissive polygon comprising transparent optical quality material;
drive means for rotating the polygon about the first axis of rotation thereby causing the through transmitted collimated multi-beam illumination beam to repetitively scan along a linear first path from a first point to a second point across an active area;
a lens wheel having a disk shape and a plurality of lenses positioned with equal spacing about the circumference of the disk;
means for rotating the lens wheel about a second axis so that each lens momentarily moves through the active area along an arcuate second path from a third point to a fourth point, wherein the first and second paths are substantially aligned with each other;
means for synchronizing each scan of the collimated multi-beam illumination beam along the linear first path to coincide with each translation of a lens along the arcuate second path so that the collimated multi-beam illumination beam is focused by successive lenses to scan successive data traces across the recording media, wherein the plurality of write beams record data marks within a corresponding plurality of data tracks within each data trace, and the read beam illuminates a recorded plurality of data tracks within each data trace with the data marks within the plurality of data tracks modulating the read beam to generate a modulated read beam; and means for detecting the modulated read beam and generating an output data signal corresponding thereto to recover the recorded data signal from the plurality of recorded data channels.

22. The apparatus for recording and recovering data as in claim 21 wherein each first light source comprises:
a laser source emitting light having a predetermined intensity, the emitted light frequency modulated by a predetermined portion of the data signal;
means for forming the emitted modulated light into a modulated write beam.

23. The apparatus for recording and recovering data as in claim 21 wherein the second light source comprises:
a laser source emitting light having a predetermined intensity;
means for forming the emitted light into a read beam; and means for shaping the read beam to illuminate an area on the recording media as the read beam scans along a data trace to read each data tracks therein.

24. The apparatus for optically recording as in claim 21 further including autofocus means comprising:
a third light source emitting an autofocus beam combined with the plurality of write beams and the read beam to form the collimated multi-beam illumination beam, the autofocus beam traced across the recording media and reflected therefrom;
a quadrant detector wherein each quadrant measures the intensity of the light focused thereon;
an astigmatic lens for focusing the reflected autofocus beam to a spot on the quadrant detector;
means for comparing the light intensity measured by each quadrant of the detector to identify the shape of the spot focused on the quadrant detector;
means for determining from the identified shape whether the illumination beam is properly focused on the recording media, the spot having a circular shape if the illumination beam is properly focused on the media, and having an elliptical shape if the illumination beam is not properly focused, and outputting an autofocus control signal indicative thereof; and means for adjusting the focus of the collimated multi-beam illumination beam on the recording media in response to the autofocus control signal.