镜头光学设计课件

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,11/7/2009,#,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,鏡頭光學規格的介紹,Curtis,主題,1,鏡頭光學規格的介紹Curtis主題1,Curtis,內容大綱,1,Pixel Size,2,Image Size,3,Image Circle,4,Lens Composition,5,Field Of View(FOV),6,F Number,7,Relative illumination (RI),8,Chief Ray Angle(CRA),9,Distortion,10,MTF,11,EFL,12,Back Focus Length(BFL),13,Optical Total Length,2,Curtis內容大綱1Pixel Size2Image Si,LCM-* 2Mega (Design),Item,LCM-*,Sensor,MI-XXXX,，OV-XXXX,Pixel Size,3.2 x 3.2m,Image Size,D:5.6 mm (H:4.48 V:3.36),Image Circle,5.9mm,Lens Composition,1,G3P,Field Of View,59.5(,at SENSOR Diagonal),F Number,F/2.8,Relative illumination at 100% of Image Height,55% (,at SENSOR Diagonal),Chief Ray Angle,D: 19.7 H: 20.6 V: 20.5,TV Distortion,1%,MTF Center,Center 54% 180 LP/mm 50% 200 LP/mm,at 70% of Image Height,h=70% T61%/S74% 90LP/mm,at 80% of Image Height,h=80% T59%/S69% 90LP/mm,at 90% of Image Height,h=90% T58%/S63% 90LP/mm,at 100% of Image Height,h=100% T59%/S72% 90LP/mm,Focus Length,f=4.87mm,Back Focus Length,1.494,mm,Optical Total Length, sensor size(D)。,2、D + 0.4mm( Package 公差)。,MEMO：光學設計的考量，要從了解SENSOR開始。,光學設計需與SENSOR達到最佳配合。,P,L,W,D,P = Pixel size,sensor1,Curtis,5,1、Image circle sensor size(D,sensor2,Curtis,尺寸表,6,sensor2Curtis尺寸表6,FOV:,Field Of View,D,f,FOV = 2,= 2 tan,-1, D / 2f ,FOV,sensor,例：SENSOR對角線D=5mm，,焦點距離f=3mm，,則FOV為：,FOV = 2,= 2 tan,-1, 5 / 2*3 ,= 79.6(,度),Curtis,7,FOV:DfFOV = 2 FOVsensor例：SE,F/#_1,D,f,sensor,F/#：決定光通量、影像的亮度。,F/# = f / D,I,0, 1 / (F/#),2,(,進光量與F/#平方成反比)。,I,0,Image Intensity,流明,照度,MEMO：F/#數值愈小 設計上困難度愈高。,FOV愈大 設計上困難度愈高。,Curtis,8,F/#_1DfsensorF/#：決定光通量、影像的亮度。I,F/#_2,F/2.8比F/4.0亮度亮兩倍。,例：F/#=2.8 & 4，,焦點距離f=50mm，,則入光大小為：,F/# = f / D；D = f / F/#,1、D(F/2.8),= 50 / 2.8 = 17.86,2,、D(F/4.0),= 50 / 4.0 = 12.5,1、D(F/2.8),= 50 / 2.8 = 17.86,2,、D(F/4.0),= 50 / 4.0 = 12.5,以圓面積計算公式計算如下：(,R,2,),1,、3.14 * 17.86,2,1002,2、3.14 * 12.5,2,491,(面積F/2.8),2,* (面積F/4.0),Curtis,9,F/#_2F/2.8比F/4.0亮度亮兩倍。例：F/#=2,F/#_3,CCD靈敏度較CMOS為高。,不致能區,線性區,飽和區,exposure,response,MEMO：CCD所使用的F/#值較大(即光圈較小)。,如果使用過大的光圈，則會落於飽和區,使得成像品質不好。,Curtis,10,F/#_3CCD靈敏度較CMOS為高。不致能區線性區飽和區,MTF1,黑,白,C,o,(B,max, B,min,) / (B,max,+ B,min,),= contrast,代表的是層次感、立體感。,Lens design Good image Quality,Image Quality：,MTF,Distortion,CRA(tele-centric angle),RI,Flare&Ghost,B,max,B,min,Curtis,11,MTF1黑白Co (Bmax Bmin) / (Bm,0,50,100,MTF,0.5,1.0,(lp/mm),MTF2,截止頻率,MTF,C,i /,C,o,C,o ：物,C,i ：像,Optical system,Non-perfect lens,因材料、加工、組立所產生的缺陷。,100%,70%,Curtis,12,050100MTF0.51.0(lp/mm)MTF2截止頻率,MTF3,S：Sagittal，弧矢面，放射狀。,T：Tangential，子午面，同心圓狀。,Curtis,13,MTF3S：Sagittal，弧矢面，放射狀。Curtis1,MTF4,0,100,1.0,(lp/mm),截止頻率,f,N,Aliasing現象,False color,Moire pattern,f,N,= Nyquist frequency,= 1 / 2p,例：p = 3.2m,fN = 1 / (2*3.2*0.001),= 1000 / 6.4,= 156 (lp/mm),MEMO：如何消除Aliasing?,利用“OLPF”,。,Curtis,14,MTF401001.0(lp/mm)截止頻率fNAlias,OLPF1,0,1.0,(lp/mm),f,N,0,1.0,鏡頭MTF,OLPF_MTF,1.0,(lp/mm),0,1.0,(lp/mm),f,N,f,N,OLPF：,1、雙折射式(Crystal、quartz),2、繞射式(grating 光柵),Curtis,15,OLPF101.0(lp/mm)fN01.0鏡頭MTFOLP,OLPF2,false colors,Curtis,16,OLPF2false colorsCurtis16,IR_CUT Filter_1,IR_CUT Filter,IR_CUT Filter,1、反射式(Reflection type)：干涉鍍膜。,2、吸收式(Absorption type)：藍玻璃。,Curtis,17,IR_CUT Filter_1IR_CUT FilterIR,IR_CUT Filter_2,規格標示例：650nm 15nm T = 50,Curtis,18,IR_CUT Filter_2規格標示例：650nm 1,IR_CUT Filter_3,反射式IR_CUT Filter的Angle shift 問題,入射角度增加，截止波長往短波長偏移。,吸收式_(藍玻璃、綠玻璃),無Angle shift 問題,但，材料特性為質軟、容易起化學變化，,容易吸水有潮解現象，耐候性不佳等問題。,Curtis,19,IR_CUT Filter_3反射式IR_CUT Filt,CRA_1,C.R.(30),CRA(,),Chief Ray Angle(CRA),A.S,I,0,I,Image plane,與CRA有關的參數：,1、cos,4, Law,： I,= I,0,cos,4,2、,RI =,I,/ I,0,(,相對照度),Curtis,20,CRA_1C.R.(30)CRA()Chief Ray,CRA_2,Sensor端會要求CRA 符合此角度配合micro lens,的調整。(micro lens與sensor的距離，影響CRA需,求的大小),例：SENSOR的CRA要求希望25，,A、RI = 50 at 30 (,),B、RI = 55 at 30 (,),誰優?,實裝上，A周邊光亮比B亮，為何?,因為，,A的CRA() = 25；,B的CRA() = 30,A比B能配合SENSOR，故A比B亮。,Curtis,21,CRA_2Sensor端會要求CRA 符合此角度配合mi,