应用光学ch28-29.ppt

1、P31: f, f P38: Fig. 2.29,Two wrong points,Review:,2. Principal planes and focal points of a coaxial(共轴的)spherical system.,1. principal planes and focal points of a single refracting surface.,Principal planes of a refracting surface,The two principal points H and H of a single spherical surface are j

2、ust at the vertex of the spherical surface. That means the first and second principal planes coincide with(与相互重合)the tangent plane crossing the vertex of the surface, as shown in Fig.2.20.,C,F,F,O,H,H,Fig. 2.20 Focal points, vertex point, principal points, tangent plane , and principal planes of a r

3、efracting surface,Focal points of a refracting surface.,Focal points of a reflected surface.,Principal planes and focal points of a coaxial(共轴的)spherical system,EFL, FFL , and BFL,EFL: the effective focal length, denotedby f or f , is the distance from the principal plane H(or H) to the second focal

4、 point F(or F).,BFL: the back effective focal length, denoted by lF, is the distance from the last virture point OK to the second focal point F.,FFL: the front effective focal length, denoted by lF, is the distance from the first virture point O1 to the second focal point F.,Assignment ：,Whats the E

5、FL, FFL and BFL of the negative lens?,Chart Illustration,F,F,H,H,EFL(- F),EFL(+ F),BFL(- LF),FFL(+ LF),2.8 Chart Illustration For Image Formation,In this section we use a drawing method, chart illustration, to find out the image. In fig.2.25, for an ideal optical system all of the rays emitted from

6、one object point will converge at one image point, so if we want to find out the image point we need only find out two special emitted rays.,Fig.2.25 Chart illustration for image formation,F,F,H,H,B,B,A,A,K,K,I,I,1,2,The two rays in common use are:,1.The ray emits from object point B and passes thro

7、ugh the first focal point F. It meets the first principal plane at point I and the second principal plane at point I, and HI=HI. The conjugate ray after passing through the system will be parallel to the axis, as shown in fig.2.25.,2.The ray BK, parallel to the system axis, will pass through the sec

8、ond focal point F. It meets the first principal plane at the point K and the second principal plane at point K, and KH=KH, as shown in Fig.2.25.,Example A:,F,F,H,H,B,B,Fig. 2.26 Point between the first focal point and the first principal plane,virtual image,Example B:,M,M,F,F,H,H,A,A,B,Fig. 2.27,N,N

9、,-,+,Question : What is the image of line AM?,real image,The image of line AM is made up of two lines: one is from A to positive infinity and another is from M to negative infinity.,M,M,F,F,H,H,A,A,B,N,N,-,+,K,K,F,F,H,H,A,A,B,B,Fig. 2.28 real image,Virtual object,Example C:,K,K,F,F,H,H,A,A,B,B,Fig.

10、2.29 real object,virtual image,Example D:,Conclusions of Chart illustration：,(1)Any incident light ray which is parallel to the system axis, will pass through the second focal point F 平行于光轴入射的光线，经过系统后过像方焦点,positive lens,negative lens,(2) Any incident light ray which passes through the first focal po

11、int will be parallel to the system axis after passing through the optical system 过物方焦点的光线，经过系统后平行于光轴出射,F,H,H,positive lens,negative lens,(3) A bundle of parallel rays which have a slope angle with the axis will intersect at one point on the secondfocal plane after passing through the optical system.

12、 倾斜于光轴的平行光线，经过系统后交于像方焦平面上某一点。,positive lens,negative lens,(4)Any incident light rays emitted from an object point which is on the first focal plane off the axis will be a bundle of parallel rays which have a slope angle with the axis. 自物方焦平面上一点发出的光束经系统后成倾斜于光轴的平行光束,positive lens,negative lens,(5) lat

13、er magnification of a couple of conjugate planes is equal to 1. 一对主平面的垂轴放大率=1。,(6) The object point on the axis also has a image point on the axis 光轴上的物点其像必在光轴上。,(7) Any incident rays which pass through the first principal point will emit from the second principal point and parallel to the incident

14、ray. Namely, Angular magnification is 1. 过主点光线方向不变。(角放大率=tgU/tgU=1),H,H,U,U,F,F,A,K,K,2.9 Image Position And Size,There are two methods for the image calculation according to two different coordinate (坐标)systems: Newtonian equation Gaussian equation,2.9.1 Newtonian equation,In Newtonian equation the

15、 coordinates of the object and image points are as follows: x: the object distance which is from the first focal point F to the object point A. the distance is positive if it is measured to the right and is negative if to the left.,x: the image distance which is from the second focal point F to the

16、image point A. The distance is positive if it is measured to the right and is negative if to the left.,2.9.1 Newtonian equation,1.ABFHIF,2. HKFABF,Newtonian equation,2.9.2 Gaussian equation,In Gaussian equation the coordinates of the object and image points are as follows: l : the object distance which is from the first principal point H to the object point A. The distance is positive if it is measured to the right and is negative if to the left.,l: the image distance which is from the second principal point H to the image point A. The distance is positive if it is measured to the rig