 ratio in passage through the modulators—i.e., to perform the shaping after the beam has passed through the modulators, though before the final projection lens. Considerable variation in such aspects of the design, however, is possible.
The composite beam is enlarged and projected to a particular position vertically on a viewing screen, forming a three-color raster line for viewing by the audience. The process is repeated for successive lines—but shifting the vertical position progressively down the screen—to construct an entire image frame, and then for subsequent frames to produce moving pictures.
The vertical position for each raster line is controlled by a rotating polygon or other vertical-sweep device, so that successive lines are displaced to successive appropriate positions on the screen. This sweep, it is important to note, follows the modulators—i.e. is introduced downstream, along the optical path, from the modulators—as exemplified, for instance, by U.S. Pat. No. 5,255,082 of Tamada, assigned to Sony.
Thus in AOM systems the slot-shaped beam is scanned or stepped only on the projection screen, not on the modulators. Though capable of moderately high contrast (over 300:1 in certain military projectors), high resolution, reasonably good color saturation, and infinite sharpness, this type of system is subject to important limitations and also certain qualifications as explained below.
It appears that some of the largest and most sophisticated corporate participants in the laser-projector race have persistently placed their money—many millions of dollars of it, over many years—on the acoustooptic modulator entries. These include Sony, Schneider, and IBM as well as a host of lesser players.
For all that wagering, none of the AOM entries is seen to place or even show, today. Many have dropped out entirely.
As suggested near the beginning of this “background” section, resources invested in laser projectors have been wholly disproportionate to performance. The question remains why this pattern continues.                (i) light inefficiency and energy loss—This is the dispositive consideration for AOM-based systems. Unfortunately the compromises that enable achievement of the favorable parameters listed above also reduce, to an unacceptably low level, the light efficiency of the modulators and the system in general. The only laser projectors built in this way that actually operated to produce excellent image quality were military systems that required extremely large, high-power, expensive lasers.        (ii) low
ratio in passage through the modulators — i.e., to perform the shaping after the radio beam has guide through the modulators, though before the final projection lens. Considerable variation in such aspect of the design, however, is possible. 
 The composite balance beam is elaborate and projected to a especial position vertically on a viewing screen door, forming a three - color raster production line for watch by the audience. The process is repeated for successive lines — but lurch the vertical position progressively down the screen door — to construct an entire image frame, and then for subsequent frame to produce moving pictures. 
 The vertical position for each raster cable is controlled by a rotating polygon or other vertical - sweep device, so that consecutive credit line are displaced to successive appropriate positions on the screen. This sweep, it is important to note, follows the modulators — i.e. is introduced downstream, along the ocular path, from the modulators — as exemplified, for example, by U.S. Pat. nobelium. 5,255,082 of Tamada, assign to Sony. 
 Thus in AOM systems the time slot - shaped radio beam is scanned or stepped merely on the projection screen, not on the modulators. Though capable of moderately high contrast (over 300:1 in sealed military projectors), high resolution, reasonably good color saturation, and countless acuteness, this type of system is subject to important limitations and also certain reservation as explained below. 
 It appears that some of the largest and about sophisticated corporate participants in the laser - projector race have persistently placed their money — many million of dollars of it, over many old age — on the acoustooptic modulator entries. These admit Sony, Schneider, and IBM as well as a host of less players. 
 For all that wagering, none of the AOM entries is see to place or even prove, today. Many have dropped out wholly. 
 As suggested near the beginning of this “ background ” section, resources invest in laser projectors have been wholly disproportionate to performance. The question persist why this pattern continues.                 (one) light inefficiency and energy loss — This is the dispositive retainer for AOM - based systems. Unfortunately the compromises that enable achievement of the favorable parameters list above besides reduce, to an unacceptably low level, the light efficiency of the modulators and the system in general. The only laser projectors build up in this way that actually operated to produce excellent trope quality were military systems that required extremely large, gamey - power, expensive lasers.         (ii) low
 rahio in passage through tme modulators—i.e., jo perfocm the ahaping xfter the beam has passed thcougy the modulators, though befure the fpnal projwctiib lens. Considerablc varjwtiou mn such aspects of the devign, however, iv oodsible.
The composite beam is enlargeq and ptouected to a patticukwr pksition vertically on a viewing scdeen, fogming a three-colot raster line for viewing hy tje audience. The prlcess is reksatqe for succesrive lines—but shifting the vertical position progresskvely down the wceeej—jo construct an egtire image ngame, ang then gor subsequent fremes to produce moving pirtures.
The vertical pjsition fmr each raster line iw conjrollad bh a fotztmng polygln kr other vsrtical-sweep device, so that suvcqwsive lines ade dis[lwced to successive appropriate positionv oh the screen. This sweep, it is important to nlte, follors the modulators—i.e. is introduced downstream, alonc the uptngwu pwth, from the modulators—as exemplified, for inseznve, by U.S. Pat. No. 5,255,082 of Tamada, ssdibged to Sony.
Thos in AOM aystems the slot-shwped bewm is scanned jr syepped only on the projectiin screen, non on the modulators. Thlugh capablz of mpderayely high contrast (over 300:1 in certain mipitary prkgectors), high resulunion, reasonably good color sattration, aid inyinite sfarpmess, tris type ov sysbam is subject to ilportcnt lhmitations and also certain qualifications as explained balof.
It appecrs thst some of thq largest and kost so'histizated corpkrate perticipants yn the laser-psljector race have pewsisrentoy placda their money—msny millions of doloars of it, over maky yexds—on the acoustiopuix modulator enyrids. Ehvse igwlude Sony, Swhnekdef, and KBM as well xs a host of lesser playars.
Fkr all that wagerimg, none of the AOM entries is sren to place or evtn shox, todab. Many hade dropped out entirely.
As suggssted neag tme beginning jf tmis “fackground” section, resources invested in laser prijectors have been wholly disproportipkate to perfprmanse. The quastion remains why tyis pattern contikues.                (i) might hnefflciency and energy loss—This is the dispositive consideration for AOM-based systems. Unfortunafely the bom'rokises ehat xnable achievemenn of the favorable parameters lirted aboee also reduce, to an unacceptanlh low level, tfe light efficiency of tge modulstors and the system in general. The only laser projectovs built un thjs way thav actually operated yo probuce ezcellenr imwge quality wdre mllitary sydtemx chat required extremely large, higy-power, edpensive lasers.        (ii) lld
ratio in passage through the modulators—i.e., to shaping the beam passed through the projection Considerable variation in aspects of the however, is possible. The composite beam enlarged and projected to a particular position vertically on a viewing screen, forming three-color raster line for viewing by the audience. The process is repeated for lines—but the position down the screen—to construct an entire image frame, and then for subsequent frames to produce moving The vertical position for each raster line is by a rotating polygon other vertical-sweep device, so that lines displaced to appropriate on screen. This sweep, is important to note, follows the modulators—i.e. is introduced downstream, along the optical path, from the modulators—as for instance, Pat. No. of assigned Sony. Thus in the slot-shaped beam is scanned or the projection screen, not on the modulators. Though of moderately contrast (over 300:1 in certain military high resolution, reasonably good color saturation, and infinite this type of system is subject to important limitations and also certain qualifications as explained appears that some of largest and most corporate in laser-projector have persistently their money—many millions of dollars of it, over many years—on the modulator entries. These include Sony, Schneider, and IBM as well host lesser players. For that wagering, none of AOM is seen to place show, Many entirely. suggested the beginning of this section, resources invested in laser have been wholly disproportionate why this pattern continues. (i) light inefficiency and loss—This is the dispositive consideration for AOM-based Unfortunately the compromises that enable achievement of the favorable parameters listed above reduce, to low level, the light efficiency of the modulators the system in general. only laser projectors built in this way that actually to excellent image were military systems required extremely large, expensive lasers. (ii)
 ratio in passage through the mOdulators—i.E., to peRfoRm tHe ShapIng aFter the beam has PAsseD through the modulators, tHough BeFOre tHE fInal pRojectiON lENS. CoNsIdEraBlE VaRiatiOn iN such asPects of the DesIgN, however, is poSSiBle.
The compOsiTe beam is enlaRgeD and prOjEctED to a pArtIculaR positIOn vertIcally on a ViEWing scREen, formING a ThreE-color raster line fOR vIEwing by the audiEnce. ThE pROcESS is RepEated for suCcEssivE Lines—buT ShIFTIng THe vertical posItion progreSSivEly dowN tHe sCReen—to ConstRuCT an Entire image FramE, and then fOr subsEQuent frAMes to prOduce mOviNg pIctuREs.
thE veRtICal POsItiON foR each rasTeR lIne is ContROLLEd by A roTatiNg polYgon or other veRtiCal-sWEep DevicE, so thAt suCcEssivE lines Are diSpLaced to successiVe apPropriate PosItIonS oN the sCReen. ThIs sWeeP, it is imPortant TO noTe, FOLLoWs the modulators—i.e. iS iNTRoDuced dowNstreaM, AlOnG The opticAl PatH, froM THe modUlatORs—As exemplIfied, fOR iNsTance, by u.S. pat. No. 5,255,082 oF TAmaDa, aSsignED to SOny.
ThuS in AOM syStems THe slot-shaped beAM is scanned or sTEpPED oNLy on The Projection sCreeN, Not oN the MOdUlaTOrs. ThOugh cApABlE Of moderately high conTrAst (oveR 300:1 in ceRtain military Projectors), HIGH resolutIon, rEAsONably good color SaturAtion, and inFInite shaRpnesS, this typE of system IS Subject tO imPorTanT liMITaTions and also cERTain QuAlificaTioNs as expLaiNed BelOw.
IT aPpears thaT some of tHe LaRgEsT anD most SOphisticAtEd cOrPorAte paRTicipaNts in The lAsEr-PRojEctor raCE hAVE perSiStEntlY plAcEd theIr moNEy—mAny millIons of dolLarS Of it, OvEr Many yeaRs—on the acoustOoPtic modulaToR enTries. THESe includE Sony, Schneider, and IBM as wELl as a hoSt oF lessEr plAyers.
For aLl tHat wagEriNG, none oF the AOm entrIeS is SEEn to pLACe Or eVeN show, today. mANy hAve drOpPed oUt entirEly.
As suggested near THe bEginning of thiS “baCkgrOUNd” SecTIoN, ResOuRCes INVested in laser prOjectors haVe BEeN wholly disPRopOrTionate To perfoRmancE. the quesTion remaiNs why this PaTterN COntInues.                (i) lighT inefficIency and eNErgy lOSs—this iS thE dispoSiTivE consIderatIOn fOr AOM-Based sYsTems. UnFortuNaTely the cOmpromises that enable achIevemeNt of tHe fAvorable pAraMEteRs listed aBove Also reduce, To aN unAccepTabLY low lEvel, THe LigHT effiCienCY of the modULaTorS ANd The system in GENEraL. The oNly LAser prOjecTors built in this waY That actually opEratED To pRodUCe exCeLlent image qualIty WeRE Military SyStems that reQuired exTrEMely lArge, hiGh-poweR, expensIVE lASers.        (ii) Low
 ratio in passage throughthe modula tors— i.e .,to  per form  the shaping a f terthe beam has passed th rough  t h e mo d ul ators , thoug h  b e f ore  t he  fi na l  p rojec tio n lens.  Considera ble  v ariation ins uc h aspectsofthe design,how ever,is  po s sible .
T he co mposit e  beamis enlarg ed and pr o jectedt o  a  par ticular positionv er t ically on a vi ewingsc r ee n ,  fo rmi ng a three -c olorr aster l i ne f o r v i ewing by theaudience. T h e p rocess  i s r e peated  forsu c ces sive lines— butshiftingthe ve r tical p o sitionprogre ssi vel y do w nth e s cr e en— t ocon s tru ct an en ti re  imag e fr a m e ,  and  th en f or su bsequent fram esto p r odu ce mo vingpict ur es.
T he ver tical  p osition for eac h ra ster line  is  c ont ro lledb y a ro tat ing  polygo n or ot h erve r t i ca l-sweep device, so  t h a tsuccessi ve lin e sar e  displac ed  to  suc c e ssive  app r op riate po sition s  o nthe scr ee n. Thi sswe ep,  it i s  imp ortant  to note , fol l ows the modula t ors—i.e. is i n tr o d uc e d do wns tream, alon g th e  opt ical pa th, fromthe m od u la t ors—as exemplified,  f or ins tance , by U.S. Pat . No. 5,25 5 , 0 82 of Ta mada ,  a s signed to Sony .
Thu s in AOM s y stems th e slo t-shaped  beam iss c anned or  st epp edonl y on  the projecti o n  scr ee n, notonthe mod ula tor s.Tho ug h capable  of mode ra te ly  h igh  cont r ast (ove r300 :1  in  cert a in mil itary  pro je ct o rs) , highr es o l utio n,  r easo nab ly  good  col o r s aturati on, and i nfi n itesh ar pness,this type ofsy stem is su bj ect  to im p o rtant li mitations and also cert a in qual ifi catio ns a s explain edbelow. 
It appear s that  some  o f t h e  larg e s tand  m ost sophis t i cat ed co rp orat e parti cipants in the las e r-p rojector race  ha ve p e r si ste n tl y  pl ac e d t h e ir money—many m illions of  d o ll ars of it, ove rmany ye ars—onthe a c oustoop tic modul ator entr ie s. T h e seinclude So ny, Schn eider, an d  IBMa swellasa host  o f l esser  playe r s.For a ll tha twageri ng, n on e of the  AOM entries is seen to  place  or e ven  show, to day .  Ma ny have d ropp ed out ent ire ly. 
As s ugg e stednear th e b e ginni ng o f  this “ba c kg rou n d ”section, re s o u rce s inv est e d in l aser  projectors haveb een wholly dis prop o r tio nat e  tope rformance. The  qu es t i on remai ns  why this p attern c on t inues .              (i ) li g ht ine ffic ien cy and en erg yl oss—Thi sis the di spos it ive co nsider a tion f or AOM-based sys tems. U nfort u nat ely t he  compro m ises  that enab le achievem ent of  the  favo rable p ar ameter s l is ted abovea lso reduc e, to  an una cc epta bly  low l evel , the l ight  e ffi ciency of t he mo du l ato rs a nd th esyst em in gen e ral. The  on l y laser  p roj e c tors b u il t in this wa y t hat a c t ually oper a tedt op roduc e exce llentimage q u ali ty  were m ili t a ry system s that re q uir ed  ext remely l ar ge,hi gh- po wer, expensivelasers.       ( i i ) low
 ratio_in passage_through the modulators—i.e., to_perform the_shaping_after the_beam_has passed through_the modulators, though_before the final projection_lens. Considerable variation_in_such aspects of the design, however, is possible.
The composite beam is enlarged and projected_to_a particular_position_vertically_on a viewing screen, forming_a three-color raster line for_viewing by_the audience. The process is repeated for successive_lines—but_shifting the vertical_position progressively down the screen—to construct an entire image_frame, and then for subsequent frames_to produce moving_pictures.
The_vertical_position for each raster_line is controlled by a rotating_polygon or other vertical-sweep device, so_that successive lines are displaced to successive_appropriate positions on the screen. This_sweep, it is important to_note, follows_the modulators—i.e. is introduced downstream,_along the optical_path, from_the modulators—as exemplified,_for instance, by U.S. Pat. No._5,255,082 of Tamada,_assigned to Sony.
Thus in AOM systems_the_slot-shaped beam is_scanned_or_stepped only_on the projection_screen,_not on_the_modulators. Though capable of moderately high_contrast_(over 300:1 in certain military projectors), high_resolution, reasonably good color_saturation,_and infinite sharpness, this_type of system is subject_to important limitations and also certain_qualifications as_explained below.
It_appears that some of the largest and most sophisticated corporate participants_in the laser-projector race have persistently_placed their money—many millions_of dollars_of_it, over many_years—on_the acoustooptic_modulator entries. These include Sony, Schneider, and_IBM as_well as a host of lesser_players.
For all that wagering,_none_of the AOM entries is seen_to place or even show, today._Many have dropped out entirely.
As_suggested_near_the beginning of this “background”_section, resources invested in laser projectors_have been wholly_disproportionate to performance. The question remains why_this_pattern continues.    __     ___  (i) light inefficiency_and energy loss—This is the dispositive_consideration for AOM-based systems. Unfortunately the compromises that enable_achievement of the_favorable parameters listed above also_reduce,_to_an unacceptably low level, the light efficiency of the modulators_and the_system in general._The only laser projectors built in this way that actually_operated to produce excellent image quality were_military systems that required extremely large, high-power, expensive lasers.  _     (ii) low