Table 1.
Materials Used in US 8,000,032 [9]
Lens | Material | Refraction Index (589.3 nm) | Abbe Number
|
First lens | OKP4HT | 1.632 | 23 |
Second lens | PMMA | 1.49 | 55.3 |
Third lens | PC | 1.586 | 29.9 |
Fourth lens | PMMA | 1.49 | 55.3 |
Table 2.
Specifications of CMOS Sensor [13]
Parameters | Specifications |
Optical format | |
Pixel size | |
Resolution | |
Image area | |
Chroma | RGB Bayer |
Nyquist frequency () | |
Table 3.
Specifications of Internally Focusing Lens System
Parameters | Specifications |
Wavelength (nm) | 486.1 |
| 587.6 |
| 656.3 |
Effective focal length (mm) | |
Working distance (mm) | Config. 1 : Infinity |
| Config. 2 : 50 |
| Config. 3 : |
Working f-number | |
FOV (degree) | |
Chief ray angle (CRA) (degree) | |
Image height (mm) | 0.5 |
Relative illumination@1.0F (%) | |
Distortion (%) | |
MTF@ @full object point | |
Table 4.
Materials Used in Optical Simulations
Lens | Material | Refraction Index (589.3 nm) | Abbe Number
|
First lens | OKP4HT | 1.632 | 23 |
Second lens | APEL | 1.543 | 56 |
Third lens | PMMA | 1.49 | 55.3 |
Fourth lens | PMMA | 1.49 | 55.3 |
Table 5.
Optical Performances of the Three Configurations
Items | Conf.1 | Conf.2 | Conf.3 |
Object height (mm) | Infinity | 23.6349 | 8.3500 |
Working distance (mm) | Infinity | 50 | 16.7480 |
Max. aperture radius (mm) | 0.3350 |
Overall lens length (mm) | 1.1997 |
Effective focal length (mm) | 0.6966 | 0.6575 | 0.4025 |
Working f/# | 3.1 | 2.9 | 2.8 |
FOV(degree) | | | |
CRA(degree) | | | |
MTF@ @ all object points | | | |
Strehl ratio @ 1.0F (%) | 98.7 | 89.7 | 99.5 |
Distortion (%) | | | |
Relative illumination @ 1.0F(%) | |
Table 6.
Surface Data of the Three Configurations
Surface Number | Radius | Axial Distance (mm) | Aper. Radius(mm) |
0 (Aperture stop) | 0 | 0.024627 | 0.1200 |
1 (First surface of the first lens) | 0.5132 | 0.124853 | 0.1750 |
2 (Second surface of the first lens) | 0.8541 | 0.023498 | 0.1750 |
3 (First surface of the second lens) | 0.3523 | 0.167066 | 0.2177 |
4 (Second surface of the second lens) | −0.4418 | Conf. 10.008270 | 0.2177 |
Conf. 20.017054 |
Conf. 30.123935 |
5 (First surface of the third lens) | −0.4106 | 0.112164 | 0.2512 |
6 (Second surface of the third lens) | 0.4875 | Conf. 10.345112 | 0.2512 |
Conf. 20.336328 |
Conf. 30.229447 |
7 (First surface of the fourth lens) | −0.3685 | 0.119517 | 0.3350 |
8 (Second surface of the fourth lens) | −1.4654 | 0.274564 | 0.3350 |
9 (Image plane) | 0 | 0 | 0.5024 |
Table 7.
Aspheric Surface Data
Surface Number | Aspheric Surface Data |
1 (First surface of the first lens) | ; |
; |
; |
; |
; |
; |
. |
2 (Second surface of the first lens) | ; |
; |
; |
; |
; |
; |
. |
3 (First surface of the second lens) | ; |
; |
; |
; |
; |
; |
. |
4 (Second surface of the second lens) | ; |
; |
; |
; |
; |
; |
. |
5 (First surface of the third lens) | ; |
; |
; |
; |
; |
; |
; |
. |
6 (Second surface of the third lens) | ; |
; |
; |
; |
; |
; |
; |
. |
7 (First surface of the fourth lens) | ; |
; |
; |
; |
; |
; |
. |
8 (Second surface of the fourth lens) | ; |
; |
; |
; |
; |
; |
. |
Table 8.
MTFs for Working Distances
| | MTF@100 lp/mm@ All Object Points |
Working Distance (mm) | Config. # | Meridional | Sagittal |
16.748 | 3 | | |
30 | 3 | | |
40 | 2 | | |
50 | 2 | | |
60 | 1 | | |
70 | 1 | | |
100 | 1 | | |
150 | 1 | | |
200 | 1 | | |
Table 9.
Depth of Focus versus MTF for Configuration 1
Object : On Axis | Object : 0.8F | Object : 1.0F |
Focus Shift (mm) | MTF | Focus Shift (mm) | MTF | Focus Shift (mm) | MTF |
−0.034 | 0.3872 | −0.034 | Meridional 0.3983 | −0.032 | Meridional 0.3948 |
−0.033 | 0.4013 | −0.033 | Meridional 0.4108 | −0.031 | Meridional 0.4063 |
| 0.4080 | | Sagittal 0.4098 | | Sagittal 0.4006 |
| 0.3944 | | Sagittal 0.3967 | | Sagittal 0.3880 |
Table 10.
Depth of Focus versus MTF for Configuration 2
Object : On Axis | Object : 0.8F | Object : 1.0F |
Focus Shift (mm) | MTF | Focus Shift (mm) | MTF | Focus Shift (mm) | MTF |
−0.020 | 0.3867 | −0.021 | Meridional 0.3934 | −0.020 | Meridional 0.3934 |
−0.019 | 0.4013 | −0.020 | Meridional 0.4060 | −0.019 | Meridional 0.4048 |
| 0.4142 | | Meridional 0.4073 | | Meridional 0.4092 |
| 0.3999 | | Meridional 0.3956 | | Meridional 0.3981 |
Table 11.
Depth of Focus versus MTF for Configuration 3
Object : On Axis | Object : 0.8F | Object : 1.0F |
Focus Shift (mm) | MTF | Focus Shift (mm) | MTF | Focus Shift (mm) | MTF |
−0.048 | 0.3974 | −0.041 | Meridional 0.3997 | −0.032 | Meridional 0.3980 |
−0.047 | 0.4036 | −0.040 | Meridional 0.4036 | −0.031 | Meridional 0.4007 |
| 0.4026 | | Meridional 0.4009 | | Meridional 0.4002 |
| 0.3970 | | Meridional 0.3975 | | Meridional 0.3976 |
Table 12.
Moving Tolerance Analysis for Configuration 1
Shift (mm) | Axial Distance 4 (mm) | Axial Distance 6 (mm) | MTF@100 lp/mm@ All Object Points |
0 | 0.00827 | 0.345112 | Meridional |
Sagittal |
−0.00827 | 0 | 0.353382 | Meridional |
Sagittal |
| 0.09037 | 0.263012 | Meridional |
Sagittal |
Table 13.
Moving Tolerance Analysis for Configuration 2
Shift (mm) | Axial Distance 4 (mm) | Axial Distance 6 (mm) | MTF@100 lp/mm@ All Object Points |
0 | 0.017054 | 0.336328 | Meridional |
| | | Sagittal |
−0.017054 | 0 | 0.353382 | Meridional |
| | | Sagittal |
| 0.122554 | 0.230828 | Meridional |
| | | Sagittal |
Table 14.
Moving Tolerance Analysis for Configuration 3
Shift (mm) | Axial Distance 4 (mm) | Axial Distance 6 (mm) | MTF@100 lp/mm@ All Object Points |
0 | 0.123935 | 0.229447 | Meridional |
| | | Sagittal |
| | | |
−0.0335 | 0.090435 | 0.262947 | Meridional |
| | | Sagittal |
| | | |
| 0.135035 | 0.218347 | Meridional Sagittal |
| | | |