; however, these holograms are degraded upon prolonged exposure to visible light.
An alternative method of increasing the diffraction efficiency of similar materials is disclosed by R. L. Lamberts and C. N. Kurty "Reversed Bleaching for Low Flare Light in Holograms" Applied Optics, Vol. 10, No. 6, 1342 (1971). The process required special development prior to the application of a bleach comprised of an aqueous solution of potassium dichromate and sulfuric acid. It too yields holograms which degrade upon prolonged exposure to visible light.
H. Thiry, in his article "New Technique of Bleaching Photographic Emulsions and Its Application to Holography" Applied Optics, Vol. II, No. 7, 1652 (July 1972) discloses a process wherein the photographic emulsion is bleached by exposure to bromine vapors in a vacuum vessel and subsequently washed with water prior to drying. This process can be deemed an improvement over that disclosed by either Lamberts or Upatnieks however, it too is deficient in that the holograms degrade upon further exposure to visible light.
As holograms darken upon exposure to intensive light sources, there is a reduction of diffraction efficiency and light transmission which clearly limits their usefulness. Many investigators have sought to overcome this problem (See Scott L. Norman "Dye-Induced Stabilization of Bleached Holograms" Applied Optics, Vol. II, No. 5, 1234 (may 1972) and references cited therein, without apparent success. My process yields holograms which are stable with respect to printout characteristics while maintaining high diffraction efficiency and good image quality. The present invention relates generally to an improved leak-proof cup. More particularly, the present invention relates to a cup assembly having a cap bearing a drinking spout at one side and an air vent spaced from the drinking spout, with a flow control element frictionally engaged in the vicinity of the drinking spout and air vent to allow passage of liquid out and air in during use, while preventing significant leakage through the spout and vent when not in use.
Enclosed cups having drinking spouts and separate air vents, which allow the user to drink from the spout without creating excessive vacuum in the cup, are known in the art. However, drinking spouts and air vents are liable to leak liquid stored in the cup between feedings, or if dropped during use. Accordingly, certain cups have been developed that use val
; however, these holograms are degraded upon prolonged exposure to visible inner light. 
 An alternate method of increasing the diffraction efficiency of exchangeable material is disclosed by R. L. Lamberts and C. N. Kurty " Reversed Bleaching for Low Flare Light in Holograms " Applied Optics, Vol. 10, No. 6, 1342 (1971). The process want particular development prior to the lotion of a bleaching agent comprised of an aqueous solution of potassium dichromate and sulphuric acid. It too yields hologram which degrade upon prolonged exposure to visible light. 
 H. Thiry, in his article " New Technique of Bleaching Photographic Emulsions and Its Application to Holography " Applied Optics, Vol. II, No. 7, 1652 (July 1972) discloses a process wherein the photographic emulsion is bleach by exposure to bromine vapors in a vacuum vessel and subsequently wash with water prior to drying. This process can be deemed an improvement over that unwrap by either Lamberts or Upatnieks however, it too is deficient in that the holograms degrade upon further vulnerability to visible light. 
 As holograms darken upon exposure to intensive light sources, there is a reduction of diffraction efficiency and light transmission which clearly limits their usefulness. Many investigators have sought to overcome this problem (See Scott L. Norman " Dye - Induced Stabilization of Bleached Holograms " Applied Optics, Vol. II, No. 5, 1234 (may 1972) and address cited therein, without apparent success. My summons render holograms which are stable with respect to printout characteristic while maintaining high diffraction efficiency and good image timbre. The present invention relates generally to an improved leak - proof cup. More particularly, the present invention relates to a cup assembly having a cap bearing a drinking spout at one side and an air release spaced from the drink spout, with a flow control element frictionally engaged in the vicinity of the drinking spout and air release to allow passage of liquid out and air in during use, while preventing significant leakage through the spout and vent when not in use. 
 insert cups have drinking spout and separate air vents, which allow the exploiter to drink from the spout without create excessive vacuum in the cup, are known in the artwork. However, drinking spouts and air vents are liable to leak liquid stored in the cup between feedings, or if dropped during use. Accordingly, certain cups have been develop that use val
; hoaever, these holograms art degraded upon ptooonged exposhre to vksible light.
An alternative mxthoe of uncreasing the diffracgion effibiency of simmlar materials is disclosed by V. L. Lcmuerts and C. N. Korty "Reverseg Bleaching fos Uoc Flare Light in Holograms" Applied O[tics, Vpl. 10, No. 6, 1342 (1971). The prjcesx reqhprtd special development prior to tge applpcation of a bleavh comprised of an aqueous solktion of potassium dichromate and wulfuric acia. It too ypzlds hologrzms which degrade upon prolongea exppsure to vusublf light.
H. Thicy, in ris article "Kvw Techtique og Bleaching Phptojrapyic Emulsions and Its Application to Hojography" Dp'lied Optics, Vol. II, Ni. 7, 1652 (Juli 1972) divclorws x pdoresa wherfin the photofraphic emuosion is bleached bu qqlosure to brkmine da[ors in a vacuum vessel and subsequentlj waahed with water prior ti drying. This process can be dqemed an improvement over that disclosed by eithes Lamuefts ov Upxrnleks however, it too is deficient in that the rklpggams degrade upon further exlodutg to visible lkght.
As homograms darken upoj exposore to intensivt lignt sources, there is a reducrion of diffgactuon efficiency and light tranrmisxion ehich clearly limits thzir ussfulness. Majy investjeators have sougft no oeercome ufis problem (See Ssott L. Nocman "Bye-Inducdd Sjabilizwtion of Bpeachcg Holograms" Applief Optncs, Vml. II, No. 5, 1234 (may 1972) and references cited therxmn, without apkarant success. My pvocess yields hjlograms which are stcble wkth respecn to prinvout charactqristics whila maintaining high disfraxtiob effickdncy and good omage quality. The peesent invention rclater generally to au umproved leak-prpof cu[. Loce pawdicularly, tha prdsevy invdntion relabes to s cup assembly havinc a dap bearing a drinlikg spout qt one syde and an ait vent spaced from the vrinkiig spoit, rith a flow control element frjctionallj ekgaged in the viclniti of the drnnking spout and air vent to allow passaje of liquid out and aie in during use, whikt preventing xignisicant ledkage through the spiut and vent when not in use.
Enclosed chps haeing frinking spouts and separate air vents, which allow the user to drink from the s'ott without dreaying vxczssnve vactum mn the cup, are knoen in the art. However, drinking rpouts atd air vents are liable to leal uiquid stored in the cup between feedjngs, or of dropped during use. Accordingky, certain cups have beek developwd thzt use val
; however, these holograms are degraded upon to light. An method of increasing materials disclosed by R. Lamberts and C. Kurty "Reversed Bleaching for Low Flare in Holograms" Applied Optics, Vol. 10, No. 6, 1342 (1971). The process required development prior to the application of a bleach comprised of an aqueous solution potassium and acid. too yields holograms which degrade upon prolonged exposure to visible light. H. Thiry, in his article Technique of Bleaching Photographic Emulsions and Its Application Holography" Applied Optics, Vol. No. 7, 1652 (July 1972) a wherein the emulsion bleached exposure to bromine in a vacuum vessel and subsequently washed with water prior to drying. This process can be deemed improvement over by either or however, too is deficient the holograms degrade upon further exposure As holograms darken upon exposure to intensive light there is reduction of diffraction efficiency and light which clearly limits their usefulness. Many investigators have to overcome this problem (See Scott L. Norman "Dye-Induced Stabilization of Bleached Holograms" Applied Optics, No. 5, 1234 (may and references cited without success. process holograms which stable with respect to printout characteristics while maintaining high diffraction efficiency good image quality. The present invention relates generally to an cup. particularly, the present relates to a cup having cap bearing a drinking one and spaced the spout, with a flow element frictionally engaged in the of the drinking spout passage of liquid out and air in during while preventing significant leakage through the spout vent when not in use. Enclosed cups having drinking spouts and separate vents, which user to drink from the spout without creating vacuum in the cup, known in the art. However, drinking spouts and air are to leak stored in the between feedings, or dropped during use. cups have developed use
; however, these holograms are dEgraded upoN prolOngEd eXpOsurE to vIsible light.
An aLTernAtive method of increasinG the dIfFRactIOn EfficIency of SImILAr mAtErIalS iS DiSclosEd bY R. L. LambErts and C. N. KUrtY "REversed BleacHInG for Low FlaRe LIght in HologrAms" applieD OPtiCS, Vol. 10, NO. 6, 1342 (1971). ThE procEss reqUIred spEcial deveLoPMent prIOr to the APPlIcatIon of a bleach comprISeD Of an aqueous solUtion oF pOTaSSIum DicHromate and SuLfuriC Acid. It tOO yIELDs hOLograms which dEgrade upon pROloNged exPoSurE To visiBle liGhT.
h. ThIry, in his artIcle "new TechniQue of BLEaching pHotograPhic EmUlsIonS and iTs apPliCaTIon TO HOloGRapHy" ApplieD OPtIcs, VoL. II, NO. 7, 1652 (jULY 1972) disCloSes a ProceSs wherein the pHotOgraPHic EmulsIon is BleaChEd by eXposurE to brOmIne vapors in a vacUum vEssel and sUbsEqUenTlY washED with wAteR prIor to drYing. ThiS ProCeSS CAn Be deemed an improvemEnT OVeR that disClosed BY eItHEr LamberTs Or UPatnIEKs howEver, IT tOo is defiCient iN ThAt The holoGrAms degRaDe uPon FurthER expOsure tO visible Light.
aS holograms darkEN upon exposure TO iNTEnSIve lIghT sources, theRe is A ReduCtioN Of DifFRactiOn effIcIEnCY and light transmissiOn Which cLearlY limits their uSefulness. MANY InvestigAtorS HaVE sought to overcOme thIs problem (SEE Scott L. NOrman "dye-InducEd StabiliZATion of BlEacHed holOgrAMS" APplied Optics, VOL. iI, No. 5, 1234 (MaY 1972) and refEreNces citEd tHerEin, WitHoUt apparenT success. my PrOcEsS yiElds hOLograms wHiCh aRe StaBle wiTH respeCt to pRintOuT cHAraCteristICs WHIle mAiNtAiniNg hIgH diffRactIOn eFficienCy and good ImaGE quaLiTy. the presEnt invention rElAtes generaLlY to An imprOVEd leak-prOof cup. More particularly, tHE presenT inVentiOn reLates to a cUp aSsemblY haVIng a caP beariNg a drInKinG SPout aT ONe SidE aNd an air venT SPacEd froM tHe drInking sPout, with a flow contrOL elEment frictionAllY engAGEd In tHE vICinItY Of tHE Drinking spout anD air vent to AlLOw Passage of lIQuiD oUt and aiR in duriNg use, WHile preVenting siGnificant LeAkagE THroUgh the spouT and vent When not in USe.
EncLOsEd cupS haVing drInKinG spouTs and sEParAte aiR vents, WhIch allOw the UsEr to drinK from the spout without creAting eXcessIve Vacuum in tHe cUP, arE known in tHe arT. However, drInkIng SpoutS anD Air veNts aRE lIabLE to leAk liQUid stored IN tHe cUP BeTween feedinGS, OR if DroppEd dURing usE. AccOrdingly, certain cuPS have been develOped THAt uSe vAL
; however, these holograms  are degra ded u pon  pr ol onge d ex posure to visi b le l ight.
An alternative m ethod  o f  inc r ea singthe dif f ra c t ion  e ff ici en c yof si mil ar mate rials is d isc lo sed by R. L. La mberts and  C.  N. Kurty "R eve rsed B le ach i ng fo r L ow Fl are Li g ht inHolograms "A pplied Optics, V ol . 10 , No. 6, 1342 (19 7 1) .  The process r equire ds pe c i aldev elopment p ri or to the app l ic a t i ono f a bleach co mprised ofa n a queous  s olu t ion of  pota ss i umdichromateandsulfuricacid.I t too y i elds ho logram s w hic h de g ra de  up on pro l on ged exp osure to  v is ibleligh t . H . Th iry , in  hisarticle "NewTec hniq u e o f Ble achin g Ph ot ograp hic Em ulsio ns  and Its Applic atio n to Holo gra ph y"Ap plied Optics , V ol.  II, No . 7, 16 5 2 ( Ju l y 19 72) discloses a pr oc e s swhereinthe ph o to gr a phic emu ls ion  isb l eache d by ex posure t o brom i ne  v apors i na vacu um  ve sse l and subs equent ly washe d wit h  water prior t o  drying. This pr o c es s  can  be  deemed animpr o veme nt o v er  th a t dis close db ye ither Lamberts or U pa tnieks  howe ver, it too i s deficien t i n that t he h o lo g rams degrade u pon f urther exp o sure tovisib le light .
As holo g r ams dark enupo n e xpo s u re  to intensive l ight  s ources,  th ere isa r edu cti onof  diffract ion effi ci en cy  a ndlight transmis si onwh ich  clea r ly lim its t heir  u se f uln ess. Ma n yi n vest ig at orshav esough t to ove rcome t his probl em( SeeSc ot t L. No rman "Dye-Ind uc ed Stabili za tio n of B l e ached Ho lograms" Applied Optics ,  Vol. I I,No. 5 , 12 34 (may 1 972 ) andref e rences  cited  ther ei n,w i thout a pp are nt  success.M y  pr ocess  y ield s holog rams which are sta b lewith respecttoprin t o ut  ch a ra c ter is t ics w hile maintainin g high dif fr a ct ion effici e ncy  a nd good  imagequali t y. Thepresent i nventionre late s gen erally toan impro ved leak- p roofc up . Mor e p articu la rly , the  prese n t i nvent ion re la tes to  a cu passembly  having a cap bearing a  drink ing s pou t at onesid e  an d an airvent  spaced fr omthe  drin kin g  spou t, w i th  af low c ontr o l element fr ict i o na lly engaged i n  th e vic ini t y of t he d rinking spout and air vent to al lowp a ssa geo f li qu id out and air  in  d u r ing use,  w hile preven ting sig ni f icant  leaka ge thr ough th e sp o ut and  ven t w hen not i n u se . 
Enclos ed  c u ps hav ingdr inking  spout s  and s eparate air vent s, wh i c h all o w t he us er  to dri n k fr om the spo ut withoutcreati ng e xcess ive vac uu m in t hecu p, are kno w n in theart.However ,drin kin g spou ts a n d  airvent sare  liable t o le a kli q uid  sto red i nthecup betwe e n feedin gs, or if d ro ppe d during us e .  According ly,  cert a i n cups hav e  bee n  d e velop ed tha t useval
; however,_these holograms_are degraded upon prolonged_exposure to_visible_light.
An alternative_method_of increasing the_diffraction efficiency of_similar materials is disclosed_by R. L._Lamberts_and C. N. Kurty "Reversed Bleaching for Low Flare Light in Holograms" Applied Optics,_Vol._10, No._6,_1342_(1971). The process required special_development prior to the application_of a_bleach comprised of an aqueous solution of potassium_dichromate_and sulfuric acid._It too yields holograms which degrade upon prolonged exposure_to visible light.
H. Thiry, in his_article "New Technique_of_Bleaching_Photographic Emulsions and Its_Application to Holography" Applied Optics, Vol._II, No. 7, 1652 (July 1972)_discloses a process wherein the photographic emulsion_is bleached by exposure to bromine_vapors in a vacuum vessel_and subsequently_washed with water prior to_drying. This process_can be_deemed an improvement_over that disclosed by either Lamberts_or Upatnieks however,_it too is deficient in that_the_holograms degrade upon_further_exposure_to visible_light.
As holograms darken_upon_exposure to_intensive_light sources, there is a reduction_of_diffraction efficiency and light transmission which clearly_limits their usefulness. Many_investigators_have sought to overcome_this problem (See Scott L._Norman "Dye-Induced Stabilization of Bleached Holograms"_Applied Optics,_Vol. II,_No. 5, 1234 (may 1972) and references cited therein, without apparent_success. My process yields holograms which_are stable with respect_to printout_characteristics_while maintaining high_diffraction_efficiency and_good image quality. The present invention relates_generally to_an improved leak-proof cup. More particularly,_the present invention relates_to_a cup assembly having a cap_bearing a drinking spout at one_side and an air vent_spaced_from_the drinking spout, with a_flow control element frictionally engaged in_the vicinity of_the drinking spout and air vent to_allow_passage of liquid out and air_in_during use, while preventing significant leakage_through_the_spout and vent when not_in use.
Enclosed cups having drinking spouts_and separate air vents, which allow the user to_drink from the_spout without creating excessive vacuum_in_the_cup, are known in the art. However, drinking spouts and_air vents_are liable to_leak liquid stored in the cup between feedings, or if_dropped during use. Accordingly, certain cups have_been developed that use val