1、Stop:光闌fieldofview:視場vigetting:漸暈Telecentricsystem:遠心光路系統(tǒng),Chapter5SelectionofImageRaysinOpticalSystems,Stop：anopeningaperturewhosecenterisattheopticaxis.,Stops,Pupils,andWindows,Lens:limitstheamountoflightwhichcanpassthroughthesystem,lens,film,Film:limitstheimagingrange.,ApertureStop,EntrancePupil,E

2、xitPupil(孔徑光闌,入瞳,出瞳),ApertureStop:theopeninginanopticalsystemthatlimitstheamountoflightthroughthesystemsentoutfromaxialpointontheobject.,EntrancePupil:theaperturestopsimageinobjectspace.,ExitPupil:theaperturestopsimageinimagespace.,5.1ApertureStop,Exam.1locatingtheaperturestopandpupils.,Aperturestop

3、,Aperturestop,Theaperturestopcanbereplacedbyaholelocatedattheentrancepupil.,Entrancepupil(virtualimage),P,Inimagespacetheaperturestopandlensisreplacedbytheexitpupil.,chiefray：araypassingthroughthecenteroftheaperturestop.,Thechiefraypassesthroughthecenteroftheaperturestop,entrancepupil,exitpupil,Entr

4、ancewindow(入射窗,簡稱“入窗”),Exitwindow(出射窗,簡稱出窗),fieldstop:Itlimitstheimagingrange.,5.2Thefieldstop(視場光闌),Fieldstopandentrancewindow,Exitwindow(出射窗,簡稱出窗),Fieldstop,Exitwindow,Angularfieldofview(視場角):theanglewhichtheentrancewindowsubtendsfromthecenterofentrancepupil.,Angularfieldofview,Vignetting(漸暈),Clea

5、rapertureofAper.stop,ClearapertureofField.stop,Commonapertureoftwostops,Thevignettingwillincreaseasthefieldangleofviewincreases.,Effectofthevignetting:,Ifasystemhasthevignetting,therewillbeatransitionareaintheimageplane,changingfrombrighttodim,withoutaclearborderline.,Vignettingcoefficient/factor(漸暈

6、系數(shù)):,linearvignettingcoefficient,Areavignettingcoefficient,5.3SelectionofImagingRaysinaApparatus,1.Foravisualapparatus,theexitpupilshouldcoincidewiththeeyepupil.,2.SelectionofImageRaysinMicroscopeandTelecentricSystem.,Example,telescope:eyepupilisastopinsystem.,TelecentricSystem,P121,Objecttelecentri

7、csystem:Itisoftenusedinthemeasuringmicroscope.Itseffectistoeliminatethemeasuringerrorcausedbythepositionerrorsoftheimageplane.,P121,Imagetelecentricsystem:Itiswidelyusedingeodeticmeasurement.Itseffectistoeliminatethemeasuringerrorcausedbythepositionerrorsoftheobjectplane.,P122,Firstfocalplane,5.4Fie

8、ldLens,1)Thefunctionofafieldlens,Ifthefieldlensisplacedexactlyattheinternalimage,ithasnoeffectonthepowerofthetelescope,butitbendstheraybundles(whichwouldotherwisemisstheeyepiece)backtowardtheaxissothattheypassthroughtheeyepiece.Inthiswaythefieldofviewmaybeincreasedwithoutincreasingthediameteroftheey

9、epiece.,2).Thefocallengthofthefieldlens,5-5DepthofField,DepthofField:thedistancebetweenthefarthestandthenearestobjectplaneswhichcanstillbeformedclearlyontheimageplane.,Thesizeoftheacceptableblurisasubjectiveconcept.,Otherequation,DepthofField:,discussion:,2.Forthephotographicobjective,Relativeapertu

10、re:,Masteringinchapter5,thefunctionofaperturestopandfieldstoplocatingaperturestop,entrancepupil,exitpupillocatingfieldstop,entrancewindow,exitwindowtheconceptofchiefray,anditspropertiestheeffectofvignettingthestructureofobjecttelecentricsystemandimagetelecentricsystemfunctionoffieldlensanditspositio

11、ncalculatingthefocallengthoffieldlensrelationshipofrelativeapertureanddepthoffield,Inameasuringmicroscopesystem,objectiveisaperturestop,andreticuleisfieldstop,asshowninfigure.Thelateralmagnificationofobjectiveisequalto1,objectdistanceis130mm,thefocallengthofeyepieceis20mm.,Exerciseinchapter5,(1)Calculat