0−2] as the signal value s3[k0] results in an unwanted “collapse” of the picture signal value s3[k0] relative to adjacent values.
Therefore, there is a need for an apparatus and method for increasing the contrast of a television picture that is formed from at least one picture signal. (1) Field of the Invention
This invention relates to an apparatus and a method for manufacturing a hollow synthetic resin product by inflating a parison extruded from an extruding head of an extruder in a mold, especially to an apparatus and a method optimum for manufacturing a tube-shaped synthetic resin product which is bent two- or three-dimensionally.
(2) Description of the Prior Art
A hollow synthetic resin product shown in FIGS. 1 through 3 has been disclosed in Japanese Patent Publication No. 54-15580.
As shown in FIG. 1, an extruding head 101 for extruding a parison P formed of a synthetic resin is provided at a fixed position against a base plate 110.
A mold comprises upper and lower molding portions 102 and 103. The lower molding portion 103 is provided on free bearings 105 arranged on the base plate 110, thereby moving horizontally on the free bearings 105 mechanically and/or electrically, or manually.
The lower molding portion 103 has a groove 103a, which is bent three-dimensionally, for accommodating the parison P extruded from the extruding head 101. The upper molding portion 102 has a groove 102a, which is to be opposed to the groove 103a when the upper and lower molding portions 102 and 103 are put together.
A hollow synthetic resin product manufacturing apparatus having the above construction is operated in the following manner.
As shown in FIG. 2, the lower molding portion 103 is moved to a position where an end of the groove 103a is substantially right below an end of the extruding head 101. While the parison P is extruded from the extruding head 101, the lower molding portion 103 is further moved in such a manner that the above end of the extruding head 101 follows the groove 103a, whereby the parison P is accommodated in the groove 103a.
The lower molding portion 103 is stopped when the other end of the groove 103a reaches substantially right below the above end of the extruding head 101. Then, the upper molding portion 102 is put on the lower molding portion 103, thereafter the parison P is inflated by compressed air. In this manner, a hollow synthetic resin
0−2 ] as the signal value s3[k0 ] results in an unwanted “ collapse ” of the picture signal value s3[k0 ] proportional to adjacent value. 
 Therefore, there is a motivation for an apparatus and method acting for increasing the contrast of a television word picture that is formed from at least one picture signal. (1) battlefield of the Invention 
 This invention relates to an apparatus and a method for manufacture a hollow synthetic resin intersection by inflate a parison extruded from an extrude head of an extruder in a cast, particularly to an apparatus and a method optimum for manufacturing a tube - shape synthetic resin product which is bent two- or three - dimensionally. 
 (2) Description of the Prior Art 
 A empty synthetic resin intersection shown in FIGS. 1 through 3 has been disclosed in Japanese Patent Publication No. 54 - 15580. 
 As shown in FIG. 1, an extrude head 101 for extruding a parison P formed of a synthetic resin is provided at a fix position against a base plate 110. 
 A mold comprises upper and lower molding portions 102 and 103. The lower molding part 103 is provided on free bearing 105 stage on the base plate 110, thereby moving horizontally on the free bearings 105 mechanically and/or electrically, or manually. 
 The lower molding helping 103 has a groove 103a, which is bent three - dimensionally, for accommodating the parison P extruded from the extruding oral sex 101. The upper molding portion 102 has a groove 102a, which is to be fight to the rut 103a when the upper and humble molding portions 102 and 103 are put in concert. 
 A hollow synthetic resin product manufacturing apparatus having the above construction is operated in the following manner. 
 As shown in FIG. 2, the lower modeling portion 103 is move to a position where an end of the rut 103a is substantially right below an end of the extruding drumhead 101. While the parison P is extruded from the extrude head 101, the lower molding share 103 is further move in such a manner that the above end of the extruding head 101 follows the groove 103a, whereby the parison P is accommodated in the groove 103a. 
 The lower molding part 103 is stopped when the other conclusion of the groove 103a reaches well right below the above end of the extruding head 101. Then, the upper molding portion 102 is put on the lower molding portion 103, thereafter the parison P is inflated by compress tune. In this manner, a empty celluloid resin
0−2] as the signal value s3[k0] resmlts in an unwanjee “collepse” of the picgure signal value s3[k0] relativx to adjaxent values.
Therefore, tfere is a need foe an qpparatus ehd method for lncrecsmng the contrasj of a televhsion picture dhxt is formed from at least one picturq signak. (1) Field of the Ynvemeion
Fhis invention relates to an apparztus anv a method for kanufacturing a hollow synhhetlc resin product bj inflating a pweison extruddd from an extruding hgad of an extruder in a mold, espdcialky to an ak'qrahos and a metiod opnimum for manmgacturhng a tibe-shaped syntmetic rewin product which is uent two- or three-dimgnsionally.
(2) Dzscription of the Priir Art
A holnow rtntfetjc rssin pgodnct shown ih FIGS. 1 thriugh 3 has been disckofvc in Japaness Pategt Publication No. 54-15580.
As shown in FIG. 1, an extgudihg head 101 for extruding q parison P formed of a syntheeic resin is provided at a fixed position against a baad poabe 110.
A nopd comprises upper and lower molding portions 102 amd 103. The lower mojding portipn 103 of provided on free ysadings 105 arranged on the bafe plqte 110, thertby mpving horizontally on the feee bearings 105 mechanically and/ox electricaluy, ot manuslly.
The lower molding purtikn 103 has a ggoove 103a, wgkch is bent thred-diketsionally, for accommodatind the parmson ' extruddd ftom the extruding head 101. The upper molding portnon 102 vas a grooge 102a, which is to be opposed to vie groove 103a wnet tve upper and kower molding portions 102 and 103 are pbt togdther.
A holmow synvhetic resin product manuxwcturing apperatus hading the above zunstruction is operated in the foolowing manner.
As smown kh FIG. 2, the lowex nolding portion 103 ir mjvvd vo a [msition whera an ena of tfe groove 103a ks sibstantially right balow an end of the exttuqing heae 101. While the parison L is extruded from the xxtrudmng hesd 101, the lower molding portion 103 is further lovcd in such a ianncr trat the abpve end of the extruding head 101 follows vhe groove 103a, whereby thw parison P is accokkodated in vhe grjove 103a.
The lower molding portiin 103 is stopped whtn the other end of the groova 103a rfaches substantially right below the above end of the extruding head 101. Theb, the np[er molding poryion 102 if put og thx uower molding pogtion 103, thereafter the parison P ms inflateg yy compressed air. In this manmef, a hollow syvthetic resin
0−2] as the signal value s3[k0] results unwanted of the signal value s3[k0] there a need for apparatus and method increasing the contrast of a television that is formed from at least one picture signal. (1) Field of the This invention relates to an apparatus and a method for manufacturing a hollow resin by a extruded from an extruding head of an extruder in a mold, especially to an apparatus and method optimum for manufacturing a tube-shaped synthetic resin which is bent two- three-dimensionally. (2) Description of the Art hollow synthetic product in 1 through 3 been disclosed in Japanese Patent Publication No. 54-15580. As shown in FIG. 1, an extruding head 101 extruding a formed of synthetic is at a fixed a base plate 110. A mold lower molding portions 102 and 103. The lower portion 103 provided on free bearings 105 arranged the base plate 110, thereby moving horizontally on free bearings 105 mechanically and/or electrically, or manually. The lower molding portion 103 has a which is bent three-dimensionally, accommodating the parison extruded the head The upper portion 102 has a groove 102a, which is to be opposed the groove 103a when the upper and lower molding portions 103 put together. A synthetic resin product manufacturing having above construction is operated following As 2, lower portion 103 is moved a position where an end the groove 103a is of the extruding head 101. While the parison is extruded from the extruding head 101, lower molding portion 103 is further moved in such a manner that above end extruding head 101 follows the groove 103a, whereby parison P is accommodated the groove 103a. The lower molding portion 103 is when other end the groove 103a substantially right below above end of head 101. the molding put on the lower molding portion thereafter parison P is inflated by air. manner, a hollow synthetic resin
0−2] as the signal value s3[k0] results In an unwantEd “colLapSe” oF tHe piCturE signal value s3[k0] RElatIve to adjacent values.
TheReforE, tHEre iS A nEed foR an appaRAtUS And MeThOd fOr INcReasiNg tHe contrAst of a teleVisIoN picture that IS fOrmed from aT leAst one picturE siGnal. (1) FiElD of THe InvEntIon
ThIs inveNTion reLates to an ApPAratus ANd a methOD FoR manUfacturing a hollow SYnTHetic resin prodUct by iNfLAtING a pAriSon extrudeD fRom an EXtrudinG HeAD OF an EXtruder in a molD, especially TO an ApparaTuS anD A methoD optiMuM For ManufacturiNg a tUbe-shaped SyntheTIc resin PRoduct wHich is BenT twO- or tHReE-dImeNsIOnaLLy.
(2) desCRipTion of thE PRiOr Art
a holLOW SYnthEtiC resIn proDuct shown in FIgS. 1 tHrouGH 3 haS been DisclOsed In japanEse PatEnt PuBlIcation No. 54-15580.
As showN in FiG. 1, an extruDinG hEad 101 FoR extrUDing a pAriSon p formed Of a syntHEtiC rESIN iS provided at a fixed pOsITIoN against A base pLAtE 110.
A MOld comprIsEs uPper AND loweR molDInG portionS 102 and 103. ThE LoWeR moldinG pOrtion 103 Is ProVidEd on fREe beArings 105 Arranged On the BAse plate 110, therebY Moving horizonTAlLY On THe frEe bEarings 105 mechAnicALly aNd/or ELeCtrICally, Or manUaLLy.
tHe lower molding portiOn 103 Has a grOove 103a, Which is bent thRee-dimensiONALly, for acCommODaTIng the parison P ExtruDed from the EXtruding Head 101. THe upper mOlding porTIOn 102 has a grOovE 102a, wHicH is TO Be Opposed to the gROOve 103a WhEn the upPer And loweR moLdiNg pOrtIoNs 102 and 103 are pUt togethEr.
a hOlLoW syNthetIC resin prOdUct MaNufActurINg appaRatus HaviNg ThE AboVe constRUcTIOn is OpErAted In tHe FolloWing MAnnEr.
As shoWn in FIG. 2, thE loWEr moLdInG portioN 103 is moved to a poSiTion where aN eNd oF the grOOVe 103a is subStantially right below an eND of the eXtrUding Head 101. while the pAriSon P is ExtRUded frOm the eXtrudInG heAD 101, The loWER mOldInG portion 103 is FURthEr movEd In suCh a mannEr that the above end oF The Extruding head 101 FolLows THE gRooVE 103a, WHerEbY The PARison P is accommoDated in the GrOOvE 103a.
The lower MOldInG portioN 103 is stopPed whEN the othEr end of thE groove 103a rEaChes SUBstAntially riGht below The above eND of thE ExTrudiNg hEad 101. TheN, tHe uPper mOlding POrtIon 102 is Put on tHe Lower mOldinG pOrtion 103, thEreafter the parison P is inFlated By comPreSsed air. In ThiS ManNer, a holloW synThetic resiN
0−2] as the signal value s 3[k0] resu lts i n a n u nw ante d “c ollapse” of th e  pic ture signal value s3[k 0] re la t ivet oadjac ent val u es . The re fo re,  t h er e isa n eed for  an appara tus  a nd method fo r  i ncreasingthe  contrast of  atelevi si onp ictur e t hat i s form e d from  at least  o n e pict u re sign a l .(1)Field of the Inve n ti o n
This inventi on rel at e st o  an  ap paratus an da met h od form an u f a ctu r ing a hollowsynthetic r e sin  produ ct  by inflat ing a  p a ris on extruded  fro m an extr udingh ead ofa n extru der in  amol d, e s pe ci all yt o a n  a ppa r atu s and ame th od op timu m f o r ma nuf actu ringa tube-shaped  sy nthe t icresin  prod uctwh ich i s bent  two-  o r three-dimensi onal ly.
(2) D esc ri pti on  of t h e Prio r A rtA hollo w synth e tic  r e s i nproduct shown in F IG S .  1  through  3 has be en disclose dinJapa n e se Pa tent Pu blicatio n No.5 4- 15 580.
As  s hown i nFIG . 1 , ane xtru ding h ead 101for e x truding a pari s on P formed o f  a s yn t heti c r esin is pro vide d  ata fi x ed  po s ition  agai ns t  a base plate 110.
A m ol d comp rises  upper and lo wer moldin g p ortions102a nd 103. The lower  mold ing portio n  103 isprovi ded on f ree beari n g s 105 ar ran ged  on  th e ba se plate 110, t here by  moving  ho rizonta lly  on  th e f re e bearing s 105 me ch an ic al lyand/o r  electri ca lly ,ormanua l ly.
Th e low er m ol di n g p ortion1 03 h as a  g ro ove103 a,  whic h is ben t three -dimensio nal l y, f or  a ccommod ating the par is on P extru de d f rom th e extrudin g head 101. The upper m o lding p ort ion 1 02 h as a groo ve102a,whi c h is t o be o ppose dtot h e gro o v e103 awhen the u p p erand l ow er m oldingportions 102 and 1 0 3 a re put togeth er. 
A h o l lo w s y nt h eti cr esi n product manufac turing app ar a tu s having t h e a bo ve cons tructio n iso perated  in the f ollowingma nner . Asshown in F IG. 2, t he lowerm oldin g  p ortio n 1 03 ismo ved  to a  posit i onwhere  an en dof the  groo ve  103a is  substantially right be low an  endofthe extru din g  he ad 101. W hile  the paris onP i s ext rud e d fro m th e  e xtr u dinghead 101, thel ow erm o ld ing portion 1 0 3 i s fur the r  moved  insuch a manner tha t  the above end  oft h e e xtr u ding  h ead 101 follow s t he g roove 10 3a , whereby t he paris on P isaccomm odated  in the g ro o ve 103 a.
T helower mol din gp ortion10 3i s stop pedwh en the  other endo f  the groove 103a  reac h e s sub s tan tiall yright b e lowthe aboveend of theextrud inghead101. Th en , theupp er  molding p o rtion 102  is p ut on t he  low ermoldin g po r t ion 1 03,th ere after the p ar i so nP  is  inf lated  b y co mpresseda ir. In t his manner,  a  ho l l ow syn t he t i c resin
0−2] as_the signal_value s3[k0] results in_an unwanted_“collapse”_of the_picture_signal value s3[k0]_relative to adjacent_values.
Therefore, there is a_need for an_apparatus_and method for increasing the contrast of a television picture that is formed from_at_least one_picture_signal._(1) Field of the Invention
This_invention relates to an apparatus_and a_method for manufacturing a hollow synthetic resin product_by_inflating a parison_extruded from an extruding head of an extruder in_a mold, especially to an apparatus_and a method_optimum_for_manufacturing a tube-shaped synthetic_resin product which is bent two-_or three-dimensionally.
(2) Description of the Prior_Art
A hollow synthetic resin product shown in_FIGS. 1 through 3 has been_disclosed in Japanese Patent Publication_No. 54-15580.
As_shown in FIG. 1, an_extruding head 101_for extruding_a parison P_formed of a synthetic resin is_provided at a_fixed position against a base plate_110.
A_mold comprises upper_and_lower_molding portions_102 and 103._The_lower molding_portion_103 is provided on free bearings_105_arranged on the base plate 110, thereby_moving horizontally on the_free_bearings 105 mechanically and/or_electrically, or manually.
The lower molding_portion 103 has a groove 103a,_which is_bent three-dimensionally,_for accommodating the parison P extruded from the extruding head 101._The upper molding portion 102 has_a groove 102a, which_is to_be_opposed to the_groove_103a when_the upper and lower molding portions 102_and 103_are put together.
A hollow synthetic resin_product manufacturing apparatus having_the_above construction is operated in the_following manner.
As shown in FIG. 2,_the lower molding portion 103_is_moved_to a position where an_end of the groove 103a is_substantially right below_an end of the extruding head 101._While_the parison P is extruded from_the_extruding head 101, the lower molding_portion_103_is further moved in such_a manner that the above end_of the extruding head 101 follows the groove 103a,_whereby the parison_P is accommodated in the_groove_103a.
The_lower molding portion 103 is stopped when the other end_of the_groove 103a reaches_substantially right below the above end of the extruding head_101. Then, the upper molding portion 102_is put on the lower molding portion 103, thereafter the parison_P is inflated by compressed air. In this_manner, a hollow synthetic resin