应用光学 英文版 chapter 3

Example 1, If we want to discern a 200mm interval at the distance of 5kilometers, Γ=？ solution： 200 mm 5 4 10 rad By the naked eye， 6 5 10 mm
s
d
Q
PY
Q
y e P
Y
l0 250mm
l0
y tan i s d
y tan e l0
the normal reading distance/明视距离
1. s f s
tan i 250 tan e f
1 l 250mm SD 4( D) 0.25
•Near point/近点: a closest point at which the eye can see an object.
The least distinct distance or near point distance/近点距离
1. Types of telescopes
a) Kepler Telescope:
f o tan tan f e
fo ' fe 1 Positive objective + Positive eyepiece
inverted real image,
0
For a normal relaxed eye: the infinite object images on the retina (视网膜).
The eye muscles are most relaxed when the eye is looking at distant objects (“at infinity”).
§3.1 Characteristics of the Eye
3.1.1、structure of the eye:
Eyes ~ camera
Iris Frontal chamber Cornea Axis Yellow spot
Choroid Retina Sclera
lens
Blind spot
a complex magnifier
The resolution of a microscope:
the smallest separation between two object points:
P186
0.61 NA
NA= nsinU — numerical aperture of the system Note that the index n and the slope of the marginal ray U are those at the object .
Near point distance/mm 70 83
20
25
-10
-7.8
100
130
30
35 40 45 50
-7.0
-5.5 -4.5 -3.5 -2.5
140
180 220 290 400
(2) Pupil accommodation
2mm ~ 8mm
3.1.3 visual Acuity
•Far point/远点:
The far point distance/远点距离: the longest distance which the eye can see clearly.
The maximum accommodation range of the eye: SD Near point — SD Far point For a normal eye:
2. The virtual image of Magnifier is at 250mm,
d s 250mm
f s f (250 d ) f f
Q
y
Q
y i
P P si
250 d 0: 1 f
s
d
Q
PY
Discussion:
1. If 1, then 2. f then,
tan i 250 tan e f
f ' 250 mm
3. A magnifier usually consists of a single lens,
15
3.2.2 The Microscope
a telescope：
0.00029
tg 0.00029 7.3 5 tg 4 10
Example 2. If a theodolite telescope, 20
If using the method of alignment of two strait lines, what is the aiming angular error? solution：
function：improve our vision ability
For a visual optical system: the human eye is the receiver of the system.
human eyes
require
?
The visual optical system
Ex.：object， l 2m 1 then, SD 0.5( D) 2 When at infinity，l
, SD 0
SD
accommodation
•The normal reading distance/明视距离: 250mm
(Distance of most distinct vision)
Structure：objective(物镜)+ eyepiece(目镜)
objective eyepiece
y
y
'
F
' o
Fe
i

250 物 目 , 目 f目
fo ' fe ' f '
A microscope
250 f
思考：比较显 微镜和放大镜 的异同？
Example： If the aiming precision of a reading microscope is 0.001mm, ? Solution: The angle when viewing an object of
0.001mm directly is 0.001 tan e e 4 10 6 250
We can add a reticule on the internal image plane for aiming and measuring.
Application: Astronomical telescopes
b) Galilean Telescope:
Positive objective + negative eyepiece
Far point/远点: at infinity
SD Near point — SD infinity The maximum accommodation range of the eye is restricted by ages.
Ages 10 15
Maximum accommodation range/Diopter -14 -12
Retina: 视网膜 Pupil: 瞳孔 Diopter: 视度 Visual acuity/Resolution: 分辨率 Myopia: 近视眼 Hyperopia: 远视眼
Instruments for Human Eyes ： magnifier, microscope and telescope
eyepiece
objective erector
f
’ 物
f目
Prism Erecting Telescope
Discussion:
tan ' tan
y
H1
f o’
H
' 1
fe
'
H2 H
' 2
y'
1/ D / D
The angular magnification, lateral magnification, axial magnification are all independent of the position of the conjugate planes.
Lens of eye~camera lens Retina(视网膜)~ film(底片) Pupil(瞳孔) ~ stop(光阑)
3.1.2 the Accommodation of the Eye
Eye , two kinds of accommodation functions： diopter accommodation and pupil accommodation (1) Diopter accommodation
y 0.006mm
'
For two points,
min 1 0.0003rad
For lines,
10
§3.2 principles of Magnifier and Microscope
The eye request visual instruments : (1) Enlarge ω (2) output rays are parallel, or the image of the instrument should be at infinity Magnifying power of the instrument（视放大率） : yi tan i ye tan e 思考： >0 ' ' i e J J yi 或<0说 y 明什么？
i 1' 0.00029 rad 0.0003 rad tan i i 0.00029 73 6 tan e e 4 10
If we use a 10 eyepiece, then the objective:
o 7.3
Using,
o 8
§3.3 principle of Telescope
Structure: objective + eyepiece Telescopes Afocal Systems（无焦系统）
Three types of telescopes: Kepler Telescope, Galilean Telescope, The erecting（正立） Telescope
The second focal point of the eye: retina
Measuring for the accommodation degree of the eye: 1 the unit : Diopter/屈光度，视度 SD l
l
——from the eye to the object plane. unit：m/meter
erect virtual image,
0,
2 ~3


Application: watching operas
c) The erecting（正立） Telescope:
Erector: lens, or prism
erect real image,
0
Application: military telescopes
e
'
'
3.2.1 The Magnifier
tan i y l0 l0 tan e s d y d s y x f s y f f l0 f s f d s
Q
y
Q
y i
P P si
the angular error in the image space： 10
the aiming angular error : then：



10
20
0.5
P184-185
2. the angular resolution of a telescope (in object space):