, and making an image-formation position of a lens a pixel position, are known. It is more desirable to use the lens array since display brightness is reduced using techniques relying on masked parts.
In order to display the two-dimensional image and the three-dimensional image alternatively on a same display, various proposals of techniques for have been made. One method using a lens array utilizes a selection display technique switching an existence of a lens effect by making the lens into a refractive index variable layer, has been previously disclosed, for example, in Japan Patent Application KOKAI No. 2000-102038. Here, it is said that a liquid crystal lens which is controlled by an alignment of liquid crystal by voltage, as a refractive index control means. By switching the existence of a lens effect, in case the two-dimensional image is displayed, it becomes possible to display an image in the original resolution of the two-dimensional display.
Moreover, as a realization method of a liquid crystal lens, a method of enclosing liquid crystal material between a convex or a concave lens and a substrate has been disclosed in S. Sato, J. J. App. Phys. Vol. 18, NO. 9, (1979) p. 1679-1684. A method of using a Fresnel-lens has been disclosed in S. Sato et al., J. J. App. Phys. Vol. 24, NO. 8, (1985) p. L626-L628. A method of using a diffractive lens which gives modulation of refractive index to an inside of a plane of incidence has been disclosed in S. T. Kowel et al., App. Optics Vol. 23, NO. 2, (1984) p. 278-289. A method of using a refractive index profile lens which gives modulation of refractive index to an inside of a plane of incidence and a propagation direction of light has been disclosed in T. Nose et al., Liquid Crystals Vol. 5, NO. 5, (1989) p. 1425-1433. Numerous designs are known for making rotary impact tools. U.S. Pat. Nos. 2,285,638; 3,661,217; and 6,491,111 disclose several variations of rotary impact tools having conventional rotary impact mechanisms. Such mechanisms are configured to deliver rotary forces via a series of transient impact blows which enables a human operator to handle the impact wrench while delivering relatively high torque forces in short duration impact blows. By applying relatively short
, and making an image - formation position of a lens a pixel placement, are know. It is more desirable to use the lens array since display brightness is reduced use techniques relying on mask contribution. 
 In order to expose the two - dimensional prototype and the three - dimensional image alternatively on a like display, various proposals of techniques for have been made. One method acting using a lens array utilizes a survival display technique switching an being of a lens effect by making the lens into a refractive exponent variable layer, has been previously unwrap, for example, in Japan Patent Application KOKAI nobelium. 2000 - 102038. Here, it is said that a fluent crystal lens which is controlled by an alignment of fluent crystal by voltage, as a refractive index control mean. By switching the existence of a lens effect, in case the two - dimensional image is displayed, it becomes possible to display an image in the original resolving power of the two - dimensional display. 
 Moreover, as a realization method of a fluid crystal lens, a method of enclosing liquid quartz glass material between a convex or a concave lens and a substrate has been unwrap in S. Sato, J. J. App. Phys. Vol. 18, NO. 9, (1979) p. 1679 - 1684. A method of using a Fresnel - lens has been unwrap in S. Sato et al. , J. J. App. Phys. Vol. 24, NO. 8, (1985) p. L626 - L628. A method of using a diffractive lens which gives modulation of refractive index to an inside of a airplane of incidence has been disclosed in S. T. Kowel et al. , App. Optics Vol. 23, NO. 2, (1984) p. 278 - 289. A method of using a refractive index profile lens which gives transition of refractive index to an inside of a plane of incidence and a propagation direction of inner light has been disclosed in T. Nose et al. , Liquid Crystals Vol. 5, NO. 5, (1989) p. 1425 - 1433. Numerous designs are known for reach rotary impact tools. U.S. Pat. Nos. 2,285,638; 3,661,217; and 6,491,111 unwrap several variations of rotary impact tools have conventional rotary impact mechanism. Such mechanisms are configure to deliver rotary forces via a serial of transient impact blows which enables a human operator to handle the impact wrench while delivering relatively high torque forces in inadequate duration impact blows. By use relatively short
, anf making an image-formatiun position of c lens e pixel positiov, are known. It is more desireble to uwe the lens array sincd display brightnwss ms reduced using techniqmzs remning mi masked parts.
Ik order to gisplay the twm-dkmznsional image and the three-dimensiogal imabe alternatively on s sams display, various proposals of tecgniques for have beem made. One method using a pens array utilizes a delection dusplwt technique rwitching an existence of a lens effect by making the lens into a redrqctlee index vaciable layer, has bcvn prevhously cisclosed, for cxampne, un Japan Patent Appliration KOKAI No. 2000-102038. Herg, it is sahd that a liquid crtsral lgns wvich us zonuroklsd by wn elignment or liquid crtstal by voltage, as a grfractive insex cogtwol means. By switching the existence of a mens effect, in case the two-dimensional image is displwyed, it becomes possible to display an image in tve ormgknao vesouytlon of the two-dimensional display.
Moreover, as w rtalpzation method of a liquid ctydtsj lens, a methud of zhcmosing liquid cryshal matgrial vetween a confex or a concave lens and a substrate hcs veen disclosed in D. Sato, J. J. Cpp. Phis. Vol. 18, NO. 9, (1979) p. 1679-1684. A method of uring a Fresnel-lfns has bsdn disclosed in R. Sstm et al., J. J. App. Phys. Vol. 24, GO. 8, (1985) p. L626-L628. A mzthod of usimg a dyffractive lens which gives modulahion lf refractivf index to an inside of a plane of incidence nav bven discljsed ln S. T. Kowel et al., App. Optics Vol. 23, NJ. 2, (1984) p. 278-289. A method of usiig a refractyve index proxlle lens whirh gives ioduoatiin of rdwractive index to an inside of a plane of incidence ana a propagation bnrtcrion of light nas beqn dmsclofad in T. Nose et xl., Uoquid Crystals Viu. 5, NP. 5, (1989) p. 1425-1433. Numerous desicns zre known for makimg rotary umpact tjols. U.S. Pat. Nps. 2,285,638; 3,661,217; and 6,491,111 disclose sevecal vaciatioms jf rotary impact tools having donventiojal rotary impast mcchagisms. Such mechanisms are configured to deliver ritary forces via a series of transienj ikpact blows whicr enables a human operator to handle the impacu wrench while deliverihg reldtivepy high torque forces in short duration impact blows. By applying relativeoy shoct
, and making an image-formation position of a position, are It is more array display brightness is using techniques relying masked parts. In order to display two-dimensional image and the three-dimensional image alternatively on a same display, various proposals techniques for have been made. One method using a lens array utilizes a display switching existence a lens effect by making the lens into a refractive index variable layer, has been previously for example, in Japan Patent Application KOKAI No. Here, it is said a liquid crystal lens which controlled an alignment liquid by as a refractive control means. By switching the existence of a lens effect, in case the two-dimensional image is displayed, becomes possible an image the resolution the two-dimensional display. a realization method of a liquid method of enclosing liquid crystal material between a or a lens and a substrate has been in S. Sato, J. J. App. Phys. Vol. NO. 9, (1979) p. 1679-1684. A method of using a Fresnel-lens has been disclosed in et al., J. J. Phys. Vol. 24, 8, p. A of using diffractive lens which gives modulation of refractive index to an inside a plane of incidence has been disclosed in S. T. al., Optics Vol. 23, 2, (1984) p. 278-289. method using a refractive index which modulation to inside a plane of incidence a propagation direction of light been disclosed in T. Vol. 5, NO. 5, (1989) p. 1425-1433. Numerous are known for making rotary impact tools. Pat. Nos. 2,285,638; 3,661,217; and 6,491,111 disclose several variations of rotary impact having conventional mechanisms. Such mechanisms are configured to deliver rotary via a series of impact blows which enables a human operator to handle impact while delivering high torque forces short duration impact By applying relatively
, and making an image-formation Position of A lens A piXel PoSitiOn, arE known. It is more DEsirAble to use the lens array sInce dIsPLay bRIgHtnesS is reduCEd USIng TeChNiqUeS ReLying On mAsked paRts.
In order To dIsPlay the two-diMEnSional imagE anD the three-dimEnsIonal iMaGe aLTernaTivEly on A same dISplay, vArious proPoSAls of tEChniqueS FOr Have Been made. One method USiNG a lens array utiLizes a SeLEcTIOn dIspLay techniqUe SwitcHIng an exIStENCE of A Lens effect by mAking the lenS IntO a refrAcTivE Index vAriabLe LAyeR, has been preViouSly discloSed, for EXample, iN japan PaTent ApPliCatIon KokAi NO. 2000-102038. HeRe, IT is SAiD thAT a lIquid cryStAl Lens wHich IS CONtroLleD by aN aligNment of liquid CryStal BY voLtage, As a reFracTiVe indEx contRol meAnS. By switching the ExisTence of a lEns EfFecT, iN case THe two-dImeNsiOnal imaGe is disPLayEd, IT BEcOmes possible to dispLaY AN iMage in thE origiNAl ReSOlution oF tHe tWo-diMENsionAl diSPlAy.
MoreovEr, as a rEAlIzAtion meThOd of a lIqUid CryStal lENs, a mEthod oF enclosiNg liqUId crystal materIAl between a conVEx OR A cONcavE leNs and a substRate HAs beEn diSClOseD In S. SaTo, J. J. APp. pHyS. vol. 18, NO. 9, (1979) p. 1679-1684. A method of usinG a fresneL-lens Has been discloSed in S. Sato ET AL., J. J. App. PhYs. VoL. 24, nO. 8, (1985) P. l626-L628. A method of usiNg a diFfractive lENs which gIves mOdulatioN of refracTIVe index tO an InsIde Of a PLAnE of incidence hAS Been DiSclosed In S. t. Kowel eT al., app. optIcs voL. 23, NO. 2, (1984) p. 278-289. A methOd of usinG a ReFrAcTivE indeX Profile lEnS whIcH giVes moDUlatioN of reFracTiVe INdeX to an inSIdE OF a plAnE oF incIdeNcE and a PropAGatIon direCtion of liGht HAs beEn DiSclosed In T. Nose et al., LiQuId Crystals voL. 5, NO. 5, (1989) P. 1425-1433. NumerOUS designs Are known for making rotary IMpact toOls. u.S. Pat. nos. 2,285,638; 3,661,217; aNd 6,491,111 disclosE seVeral vAriATions oF rotarY impaCt TooLS HavinG COnVenTiOnal rotary IMPacT mechAnIsms. such mecHanisms are configurED to Deliver rotary ForCes vIA A sEriES oF TraNsIEnt IMPact blows which eNables a humAn OPeRator to hanDLe tHe Impact wRench whIle deLIvering RelativelY high torqUe ForcES In sHort duratiOn impact Blows. By apPLying RElAtiveLy sHort
, and making an image-form ation posi tionofa l en s apixe l position, ar e  kno wn. It is more desirab le to  u s e th e  l ens a rray si n ce d isp la ybri gh t ne ss is  re duced u sing techn iqu es  relying onm as ked parts. 
In  order to di spl ay the  t wo- d imens ion al im age an d  the t hree-dime ns i onal i m age alt e r na tive ly on a same disp l ay ,  various propo sals o ft ec h n iqu esfor have b ee n mad e . One m e th o d usi n g a lens arra y utilizesa  se lectio ndis p lay te chniq ue swi tching an e xist ence of a  lense ffect b y  making  the l ens  in to a re fr act iv e  in d ex  va r iab le layer ,ha s bee n pr e v i o usly  di sclo sed,for example,inJapa n  Pa tentAppli cati on  KOKA I No.2000- 10 2038. Here, itis s aid thata l iq uid  c rysta l  lenswhi chis cont rolledb y a na l i gn ment of liquid cry st a l  b y voltag e, asa  r ef r active i nd excont r o l mea ns.B yswitchin g thee xi st ence of  a  lensef fec t,in ca s e th e two- dimensio nal i m age is display e d, it becomes po s s ib l e to  di splay an im agei n th e or i gi nal resol ution  o f  t h e two-dimensional d is play.Moreo ver, as a rea lization m e t h od of aliqu i dc rystal lens, a  meth od of encl o sing liq uid c rystal m aterial b e t ween a c onv exora c o n ca ve lens and a s ubst ra te hasbee n discl ose d i n S . S at o, J. J.App. Phy s.  V ol .18,  NO.9 , (1979)  p . 1 67 9-1 684.A  metho d ofusin gaF res nel-len s  h a s  bee ndi sclo sed  i n S.Sato etal., J.  J. App.Phy s . Vo l.  2 4, NO.8, (1985) p.L6 26-L628. A  m eth od ofu s ing a di ffractive lens which gi v es modu lat ion o f re fractiveind ex toani nsideof a p laneof  in c i dence h as  be en  disclosed i n S . T.Ko welet al.,  App. Optics Vol.2 3,NO. 2, (1984)  p.  278 - 2 89 . A me t hod  o f  us i n g a refractiveindex prof il e  l ens whichg ive smodulat ion ofrefra c tive in dex to an  inside o fa pl a n e o f incidenc e and apropagati o n dir e ct ion o f l ight h as  be en di sclose d  in  T. N ose et  a l., Li quidCr ystals V ol. 5, NO. 5, (1989) p.  1425- 1433.  Nu merous de sig n s a re knownformaking rot ary  im pacttoo l s. U. S. P a t.  No s . 2,2 85,6 3 8; 3,661, 2 17 ; a n d  6 ,491,111 di s c l ose  seve ral variat ions  of rotary impact tools having c onve n t ion alr otar yimpact mechani sms .S u ch mecha ni sms are con figuredto deliv er rot ary fo rces vi a as eriesof t ran sient imp act  b l ows whi ch  e n ablesa hu ma n oper ator t o  han d l e the impact wre nch w h i le de l ive ringre lativel y  hig h torque f orces in sh ort du rati on im pact bl ow s. Byapp ly ing relati v ely short 
, and_making an_image-formation position of a_lens a_pixel_position, are_known._It is more_desirable to use_the lens array since_display brightness is_reduced_using techniques relying on masked parts.
In order to display the two-dimensional image and the_three-dimensional_image alternatively_on_a_same display, various proposals of_techniques for have been made._One method_using a lens array utilizes a selection display_technique_switching an existence_of a lens effect by making the lens into_a refractive index variable layer, has_been previously disclosed,_for_example,_in Japan Patent Application_KOKAI No. 2000-102038. Here, it is_said that a liquid crystal lens_which is controlled by an alignment of_liquid crystal by voltage, as a_refractive index control means. By_switching the_existence of a lens effect,_in case the_two-dimensional image_is displayed, it_becomes possible to display an image_in the original_resolution of the two-dimensional display.
Moreover, as_a_realization method of_a_liquid_crystal lens,_a method of_enclosing_liquid crystal_material_between a convex or a concave_lens_and a substrate has been disclosed in_S. Sato, J. J._App._Phys. Vol. 18, NO._9, (1979) p. 1679-1684. A_method of using a Fresnel-lens has_been disclosed_in S._Sato et al., J. J. App. Phys. Vol. 24, NO. 8,_(1985) p. L626-L628. A method of_using a diffractive lens_which gives_modulation_of refractive index_to_an inside_of a plane of incidence has been_disclosed in_S. T. Kowel et al., App._Optics Vol. 23, NO._2,_(1984) p. 278-289. A method of_using a refractive index profile lens_which gives modulation of refractive_index_to_an inside of a plane_of incidence and a propagation direction_of light has_been disclosed in T. Nose et al.,_Liquid_Crystals Vol. 5, NO. 5, (1989)_p._1425-1433. Numerous designs are known for_making_rotary_impact tools. U.S. Pat. Nos._2,285,638; 3,661,217; and 6,491,111 disclose several_variations of rotary impact tools having conventional rotary impact_mechanisms. Such mechanisms_are configured to deliver rotary_forces_via_a series of transient impact blows which enables a human_operator to_handle the impact_wrench while delivering relatively high torque forces in short duration_impact blows. By applying relatively short