Abstract:
A projection television system (10) is provided which has a CRT (16) with a curved faceplate and a projection lens system (13) for forming an image on a screen (14). The projection lens system (13) is characterized by a power lens unit (U2) which (a) provides color correction for the lens system and (b) has two positive lens elements and a negative lens element with one of said positive lens elements (L P ) being at the image side of the unit. The positive lens element (L P ) at the image side of the second lens unit (U2) is preferably the strongest positive lens element in the lens system, having a focal length (f P ) which is less than 1.5 times the focal length of the system (f 0 ).

Description:
CROSS REFERENCE TO RELATED PROVISIONAL APPLICATION 
     This application claims the benefit under 35 USC §119(e) of U.S. Provisional Application Ser. No. 60/034,932 filed Jan. 13, 1997, which is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to projection lens systems for use in projection televisions and, in particular, to color corrected, wide field of view, high numerical aperture projection lens systems for use with cathode ray tubes (CRTs) having curved faceplates. 
     BACKGROUND OF THE INVENTION 
     Various color-corrected high image quality lenses for use in high definition TV displays (HDTV) and in the projection of data and graphics are known in the art. These lenses are most frequently used in &#34;front screen&#34; two piece systems, i.e. systems where the projector and the screen are two different units. As a result of the long distance between the projector and the screen, most of the lenses used in such systems have a half field of view of under 30°. 
     In recent years, one piece projection TVs have become increasingly popular. These systems utilize a &#34;rear screen&#34; configuration in which the image is projected onto the rear surface of a translucent screen which is combined with the projector into a single unit. To achieve a small overall size for such systems, the lens must have a field of view as wide as possible. 
     To help achieve this goal and to provide for an increased amount of light at the outer portions of the image, CRTs having curved faceplates are most often used in this application. The faceplates of such CRTs are plano-convex shaped with the phosphor being deposited onto the curved side of the faceplate. As a result, the outer portion of the phosphor side of the faceplate curves towards the lens. 
     Presenting the CRT image on a surface concave towards the projection lens allows the lens to achieve a half field of view in excess of 40° and, in some cases, in excess of 45°. However the control of electron beam spot size on a curved phosphor surface is much more difficult than on a flat surface. Spot size control is important since a small and well controlled spot size is required to produce a high quality image. 
     As long as spot size was fairly large, projection lenses did not need to be corrected for axial color. However, since the introduction of digital TV (e.g., satellite TV and DVD), the quality level of one piece rear projection TV sets for consumer use has been significantly raised. 
     Manufacturers of such systems are now more willing to use more complicated electronics to minimize and control the size of the spot on a curved phosphor surface, e.g., they are willing to produce spot sizes whose sizes are 0.15 millimeters or less. Consequently, new high quality wide field of view large aperture lenses are needed to compliment the higher quality outputs of curved phosphor CRTs. As with the optics used in data and graphics projection TV systems, these new lenses need to be corrected for color. 
     A typical color corrected lens used with a flat faceplate CRT consists from long conjugate to short of a front weak aspherical unit, a main power unit which includes a color correcting doublet and a strong positive element having most of the power of the lens, a corrector unit following the main power unit and having at least one aspherical surface, and a strong negative power unit associated with the CRT faceplate and providing most of the correction for the field curvature of the lens. 
     From the image side, the main power unit typically has a negative element followed by a positive element of similar focal length but of opposite sign. These two elements provide color correction for the lens and their combined shape is typically meniscus towards the long conjugate. The single positive element providing most of the power of the lens usually follows the color correcting doublet. 
     In accordance with the present invention, it has been found that when the CRT faceplate is curved, the simultaneous correction of chromatic and monochromatic aberrations using commonly available glass is difficult to achieve when the leading element in the color correcting arrangement is negative and the overall shape of the color correcting doublet is meniscus towards the long conjugate of the lens. In particular, it has been found that the correction of lateral color is not good enough to obtain a sufficiently high level of image quality. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, it is an object of the present invention to provide a projection lens system which (1) has a large aperture, i.e., a f/number of about 1.2 or less, (2) has a wide field of view, i.e., a half field of view of at least 35°, and (3) provides a high level of correction of both chromatic and monochromatic aberrations when used with a curved phosphor CRT faceplate. 
     To achieve these and other objects, the invention provides a projection lens system which from long conjugate to short comprises a front lens unit (first lens unit; U1) comprising at least one aspherical element, a positive power lens unit (second lens unit; U2) providing most of the power of the lens system as well as correction of chromatic aberrations, a corrector lens unit (U CR ) comprising at least one aspherical element, and a strong negative power unit (third lens unit; U3) associated with the CRT faceplate having a strong concave surface facing the long conjugate and providing most of the correction of the field curvature of the lens. The positive power lens units of the invention are characterized in that they always have a positive element (L P ) on the long conjugate side of the unit. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1-5 are schematic side views of lens systems constructed in accordance with the invention. 
     FIG. 6 is a schematic diagram of a rear projection TV employing a lens system constructed in accordance with the invention. 
     The foregoing drawings, which are incorporated in and constitute part of the specification, illustrate preferred embodiments of the invention, and together with the description, serve to explain the principles of the invention. It is to be understood, of course, that both the drawings and the description are explanatory only and are not restrictive of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The lens systems of the invention preferably include a first lens unit, a second lens unit, a third lens unit, and a corrector lens unit wherein: 1) the first lens unit includes at least one aspherical surface; 2) the second lens unit (a) has a positive lens element at its long conjugate side, (b) provides color correction, and (c) has a strong positive optical power; 3) the third lens unit corrects for the field curvature of the lens system and has a relatively strong negative optical power; and 4) the corrector lens unit provides correction for, among other things, aberrations due to off-axis rays and has a relatively weak optical power. 
     The first lens unit serves to correct aperture type aberrations including spherical aberration and coma. As illustrated by the examples presented below, this unit can be composed of one or more lens elements. Preferably, the elements of this unit are composed of a plastic material. 
     The second lens unit preferably provides the majority of the lens system&#39;s positive optical power. This unit preferably includes three lens elements, namely, a positive first lens element preferably composed of glass, a second lens element preferably composed of glass which is preferably negative, but may also be positive, and a third lens element preferably composed of glass which has a power opposite to that of the second lens element. The first lens element of this unit is preferably the strongest positive lens element of the system and will be referred to hereinafter as the &#34;positive power lens element.&#34; The second and third lens elements of this unit have appropriate optical dispersions and powers to provide axial color correction for the lens system. 
     The corrector unit and third lens unit serve to correct off-axis aperture dependent aberrations and field dependent aberrations, respectively. In particular, the corrector unit is effective in dealing with oblique spherical aberrations, while the third lens unit is effective in reducing the system&#39;s field curvature. 
     As illustrated by the examples presented below, the corrector lens unit can be composed of one or more lens elements. Preferably, the elements of this unit are composed of a plastic material. 
     The third lens unit is preferably composed of an aspherical plastic lens element which contacts the fluid which couples the lens system to the faceplate of the CRT. If desired, the aspherical plastic lens element of the third lens unit can include an absorptive color filter material in accordance with Wessling, U.S. Pat. No. 5,055,922. 
     Quantitatively, the ratio of the absolute value of the focal length (f 1 ) of the first lens unit to the overall focal length (f 0 ) of the projection lens is preferably greater than 2.5; the ratio of the focal length (f 2 ) of the second lens unit to the overall focal length of the projection lens is preferably less than 1.5; the ratio of the absolute value of the focal length (f CR ) of the corrector lens unit to the overall focal length of the projection lens is preferably greater than 2.0; and the ratio of the absolute value of the focal length (f 3 ) of the third lens unit to the overall focal length of the projection lens is preferably less than 2.5. The ratio of the focal length (f P ) of the positive power lens element of the second lens unit to the overall focal length of the projection lens is preferably less than 1.5. 
     FIGS. 1-5 illustrate various projection lenses constructed in accordance with the invention. Corresponding prescriptions appear in Tables 1-5. HOYA or SCHOTT designations are used for the glasses employed in the lens systems. Equivalent glasses made by other manufacturers can be used in the practice of the invention. Industry acceptable materials are used for the plastic elements. 
     The aspheric coefficients set forth in the tables are for use in the following equation ##EQU1## where z is the surface sag at a distance y from the optical axis of the system, c is the curvature of the lens at the optical axis, and k is a conic constant, which is zero except where indicated in the prescriptions of Tables 1-5. 
     The designation &#34;a&#34; associated with various surfaces in the tables represents an aspheric surface, i.e., a surface for which at least one of D, E, F, G, H, or I in the above equation is not zero. The designation &#34;c&#34; represents a conic surface, i.e., a surface for which k in the above equation is not zero. All dimensions given in the tables are in millimeters. The tables are constructed on the assumption that light travels from left to right in the figures. In actual practice, the viewing screen will be on the left and the CRT will be on the right, and light will travel from right to left. 
     The CRT faceplate constitutes surfaces 13-14 in FIG. 1, surfaces 15-16 in FIGS. 2 and 3, and surfaces 17-18 in FIGS. 4 and 5. A coupling fluid is located between surfaces 12-13 in FIG. 1, surfaces 14-15 in FIGS. 2 and 3, and surfaces 16-17 in FIGS. 4 and 5. The material designations for these components are set forth as six digit numbers in the tables, where a N e  value for the material is obtained by adding 1,000 to the first three digits of the designation, and a V e  value is obtained from the last three digits by placing a decimal point before the last digit. 
     In Table 1, the first lens unit comprises surfaces 1-2, the second lens unit comprises surfaces 3-8, the corrector lens unit comprises surfaces 9-10, and the third lens unit comprises surfaces 11-14. 
     In Table 2, the first lens unit comprises surfaces 1-2, the second lens unit comprises surfaces 3-8, the corrector lens unit comprises surfaces 9-12, and the third lens unit comprises surfaces 13-16. 
     In Table 3, the first lens unit comprises surfaces 1-4, the second lens unit comprises surfaces 5-10, the corrector lens unit comprises surfaces 11-12, and the third lens unit comprises surfaces 13-16. 
     In Tables 4 and 5, the first lens unit comprises surfaces 1-4, the second lens unit comprises surfaces 5-10, the corrector lens unit comprises surfaces 11-14, and the third lens unit comprises surfaces 15-18. 
     Table 6 summarizes various properties of the lens systems of the invention. As shown therein, the lens systems of Tables 1-5 have the various preferred properties referred to above. In this table, the designation &#34;1/2 w&#34; represents the half field of view of the lens system. With regard to color correction, the lens systems of Tables 1-5 achieve levels of lateral color correction of less than 0.15 millimeters at the phosphor screen for wavelengths from 480 nanometers to 640 nanometers, i.e., they achieve a level of color correction better than the spot size used for digital TV images. 
     FIG. 6 is a schematic diagram of a CRT projection television 10 constructed in accordance with the invention. As shown in this figure, projection television 10 includes cabinet 12 having projection screen 14 along its front face and slanted mirror 18 along its back face. Module 13 schematically illustrates a lens system constructed in accordance with the invention and module 16 illustrates its associated CRT tube. In practice, three lens systems 13 and three CRT tubes 16 are used to project red, green, and blue images onto screen 14. 
     Although specific embodiments of the invention have been described and illustrated, it is to be understood that a variety of modifications which do not depart from the scope and spirit of the invention will be evident to persons of ordinary skill in the art from the foregoing disclosure. 
     
                       TABLE 1______________________________________Surf.                                 Clear ApertureNo.  Type   Radius   Thickness                         Glass   Diameter______________________________________ 1   a      75.9254  9.00000  ACRYLIC 77.98 2   a      104.3505 13.19380         73.89 3          103.5327 18.00000 SK18    76.74 4          -109.7000                0.20000          76.79 5          763.8706 4.00000  SF13    73.78 6          75.6031  1.50000          71.30 7          76.0645  17.00000 SK18    72.99 8          -136.7573                2.51497          73.02 9   a      -113.6070                8.00000  ACRYLIC 70.8410   a      -175.9901                Space 1          68.8911   a      -51.7837 4.00000  ACRYLIC 72.0512          -45.0000 10.00000 423500  78.1413          ∞  13.00000 560500  130.0014          -350.0000                Image distance   130.00______________________________________Symbol Descriptiona - Polynomial asphereObject and Image Surface  Surface        Radius______________________________________  Image -350.0000______________________________________Even Polynomial AspheresSurf. No.  D             E          F______________________________________ 1     -1.8029E - 06 -1.7193E - 09                           -4.1653E - 13 2     -6.2849E - 07 -1.5207E - 09                           -9.7477E - 14 9      3.5440E - 06 -1.5917E - 09                            3.1581E - 1210      3.1798E - 06  1.9390E - 09                           -6.2159E - 1211     -8.0531E - 06  1.6131E - 08                           -3.3448E - 11______________________________________Surf. No.  G             H          I______________________________________ 1      2.8754E - 16  2.7542E - 19                           -1.1474E - 22 2      2.5200E - 16  3.4831E - 19                           -1.6022E - 22 9     -4.1931E - 15  2.5658E - 18                           -5.7526E - 2210      8.6420E - 15 -5.8716E - 18                            1.5947E - 2111      3.6979E - 14 -2.1050E - 17                            4.6654E - 21______________________________________Variable SpacesZoom    Space 1       Focal   ImagePos.    T(10)         Shift   Distance______________________________________1       31.031        -0.681  0.0002       30.366        -0.337  0.000______________________________________First-Order Data______________________________________f/number          1.24     1.23Magnification     -0.1167  -0.1013Object Height     -584.20  -673.10Object Distance   -731.56  -835.05Effective Focal Length             76.679   77.021Image Distance    0.00     0.00Overall Length    863.00   965.82Forward Vertex Distance             131.44   130.77Barrel Length     131.44   130.77Stop Surface Number             3        3Distance to Stop  4.70     4.70Stop Diameter     76.829   76.300Entrance Pupil Distance             24.312   24.312Exit Pupil Distance             -67.640  -67.279______________________________________First Order Properties of ElementsElement SurfaceNumber Numbers         Power       f&#39;______________________________________1               1     2      0.19569E - 02                                  511.002               3     4      0.11643E - 01                                  85.8913               5     6     -0.88817E - 02                                 -112.594               7     8      0.12711E - 01                                  78.6755               9    10     -0.14753E - 02                                 -677.816              11    12      0.17176E - 02                                  582.207              12    13     -0.94067E - 02                                 -106.318              13    14      0.16000E - 02                                  625.006     8        11    14     -0.60935E - 02                                 -164.11______________________________________Element SurfaceNumber Numbers        lpp         l&#39;pp______________________________________1               1     2    -14.568   -20.0232               3     4     5.5065   -5.83463               5     6     2.5473    0.252124               7     8     3.8212   -6.87025               9    10    -10.185   -15.7776              11    12     17.107    14.8667              12    13     0.33015E - 07                                -7.02598              13    14     8.3333    0.33458E - 066     8        11    14    -5.4074   -24.177______________________________________ 
    
     
                       TABLE 2______________________________________Surf.                                 Clear ApertureNo.  Type   Radius   Thickness                         Glass   Diameter______________________________________ 1   a      78.1234  9.00000  ACRYLIC 80.44 2   ac     95.7568  12.51433         73.44 3          100.9258 18.00000 SK18    74.89 4          -100.9258                0.20000          74.76 5          -170.2562                4.00000  SF4     72.53 6          156.9671 0.19835          70.96 7          162.8714 16.00000 SK18    70.98 8          -82.6935 0.20000          71.35 9   a      58.9473  6.00000  ACRYLIC 68.6610   a      42.6679  10.59490         66.5811   a      -351.9562                10.00000 ACRYLIC 66.6312   c      -79.5372 Space 1          68.7013   a      -40.0417 4.00000  ACRYLIC 73.0814          -45.0000 9.00000  423500  78.2715          ∞  14.10000 563500  130.0016          -350.0000                Image distance   130.00______________________________________Symbol Description     a - Polynomial asphere     c - Conic section     Object and Image Surface  Surface        Radius______________________________________  Image -350.0000______________________________________Conics  Surface  Number        Constant______________________________________   2     2.3606E + 00  12    -3.9930E + 00______________________________________Even Polynomial AspheresSurf. No.  D             E          F______________________________________ 1     -8.8369E - 07 -5.2235E - 10                           -2.4140E - 13 2      9.2707E - 08 -4.8079E - 11                            1.3624E - 14 9     -6.4344E - 06  3.1413E - 09                           -4.3581E - 1310     -6.8817E - 06  4.6463E - 09                           -8.8108E - 1211      1.7262E - 06 -3.7483E - 09                            1.0024E - 1113     -4.5889E - 06  1.6253E - 08                           -3.1557E - 11______________________________________Surf. No.  G             H          I______________________________________ 1      1.9448E - 16 -1.4562E - 19                            4.1180E - 23 2      8.0193E - 18 -9.5624E - 22                           -2.8791E - 24 9     -5.6950E - 16  1.2426E - 19                            1.5610E - 2210      1.3192E - 14 -1.0078E - 17                            2.8873E - 2111     -1.4338E - 14  1.0363E - 17                           -3.1241E - 2113      3.6166E - 14 -2.2102E - 17                            5.6074E - 21______________________________________Variable SpacesZoom    Space 1       Focal   ImagePos.    T(12)         Shift   Distance______________________________________1       22.731        -0.184  0.0002       22.012        0.022   0.000______________________________________First-Order Data______________________________________f/number         1.24         1.23Magnification   -0.1167      -0.1013Object Height   -584.20      -673.10Object Distance -726.46      -831.18Effective Focal Length            75.972       76.515Image Distance  -.10075E - 03                        -.10962E - 03Overall Length   863.00       967.00Forward Vertex Distance            136.54       135.82Barrel Length    136.54       135.82Stop Surface Number            3            3Distance to Stop            14.41        14.41Stop Diameter    74.623       74.260Entrance Pupil Distance            30.585       30.585Exit Pupil Distance           -63.002      -62.702______________________________________First Order Properties of ElementsElement SurfaceNumber Numbers         Power       f&#39;______________________________________1               1     2      0.13603E - 02                                  735.152               3     4      0.12265E - 01                                  81.5313               5     6     -0.93753E - 02                                 -106.664               7     8      0.11395E - 01                                  87.7615               9    10     -0.28066E - 02                                 -356.306              11    12      0.48635E - 02                                  205.617              13    14     -0.99642E - 03                                 -1003.68              14    15     -0.94067E - 02                                 -106.319              15    16      0.16086E - 02                                  621.677     9        13    16     -0.87876E - 02                                 -113.80______________________________________Element SurfaceNumber Numbers        lpp         l&#39;pp______________________________________1               1     2    -22.840   -27.9952               3     4     5.6815   -5.68153               5     6     1.1752   -1.08354               7     8     6.6346   -3.36855               9    10     16.562    11.9886              11    12     8.5453    1.93117              13    14    -29.488   -33.1408              14    15     0.33015E - 07                                -6.32339              15    16     9.0211    0.66198E - 067     9        13    16    -3.7644   -22.465______________________________________ 
    
     
                       TABLE 3______________________________________Surf.                                 Clear ApertureNo.  Type   Radius    Thickness                          Glass  Diameter______________________________________ 1   a      75.3275   9.00000  ACRYLIC                                 85.75 2   a      101.5103  13.04334        81.71 3   a      -78.2772  9.00000  ACRYLIC                                 81.53 4   a      -65.4519  0.50000         81.19 5          64.9785   22.70542 BACD18 81.02 6          -199.5574 0.50000         78.41 7          -10067.2405                 4.00000  FD10   76.03 8          64.8920   0.40460         72.14 9          63.6521   14.00000 SK5    72.6410          699.7213  3.77308         71.9711   a      -206.2623 9.00000  ACRYLIC                                 71.6912   a      -101.9762 Space 1         70.0213   a      -50.2233  4.00000  ACRYLIC                                 72.2314          -44.5060  10.00000 423500 77.6015          ∞   13.00000 560500 130.0016          -350.0000 Image distance  130.00______________________________________Symbol Descriptiona - Polynomial asphereObject and Image Surface  Surface        Radius______________________________________  Image -350.0000______________________________________Even Polynomial AspheresSurf. No.  D             E          F______________________________________ 1     -1.4648E - 06 -7.1777E - 10                           -8.2347E - 13 2     -4.7680E - 07 -6.5540E - 10                           -3.8711E - 13 3      1.0442E - 06  2.4385E - 10                           -3.8441E - 15 4      9.4890E - 07 -4.6092E - 10                            2.3843E - 1311      2.8701E - 07 -6.9913E - 10                            2.9784E - 1212      6.9145E - 07  2.8489E - 09                           -5.2728E - 1213     -5.0308E - 06  4.0069E - 09                           -3.3618E - 12______________________________________Surf. No.  G             H          I______________________________________ 1      8.2100E - 18  3.0400E - 19                           -7.5061E - 23 2      1.4985E - 16  2.7016E - 19                           -9.5863E - 23 3      8.5613E - 17  3.0480E - 20                           -2.1414E - 23 4     -1.6869E - 17 -4.2323E - 20                            1.3611E - 2311     -3.4379E - 15  2.0972E - 18                           -5.2091E - 2212      8.0919E - 15 -5.6980E - 18                            1.6113E - 2113      6.1594E - 16  3.2548E - 19                           -2.9596E - 22______________________________________Variable SpacesZoom    Space 1       Focal   ImagePos.    T(12)         Shift   Distance______________________________________1       25.084        -0.336  -0.0102       24.416        -0.089  -0.010______________________________________First-Order Data______________________________________f/number         1.14         1.13Magnification   -0.0935      -0.0794Object Height   -730.00      -860.00Object Distance -911.87      -1065.1Effective Focal Length            78.321       78.691Image Distance  -.97413E - 02                        -.98614E - 02Overall Length   1049.9       1202.4Forward Vertex Distance            138.00       137.33Barrel Length    138.01       137.34Stop Surface Number            5            5Distance to Stop            10.10        10.10Stop Diameter    83.304       82.839Entrance Pupil Distance            35.323       35.323Exit Pupil Distance           -63.176      -62.798______________________________________First Order Properties of ElementsElement SurfaceNumber Numbers         Power       f&#39;______________________________________1               1     2      0.18829E - 02                                  531.102               3     4      0.15228E - 02                                  656.703               5     6      0.12644E - 01                                  79.0894               7     8     -0.11391E - 01                                 -87.7905               9    10      0.85153E - 02                                  117.446              11    12      0.25180E - 02                                  397.147              13    14      0.15551E - 02                                  643.068              14    15     -0.95111E - 02                                 -105.149              15    16      0.16000E - 02                                  625.007     9        13    16     -0.63626E - 02                                 -157.17______________________________________Element SurfaceNumber Numbers        lpp         l&#39;pp______________________________________1               1     2    -15.565   -20.9762               3     4     29.849    24.9583               5     6     3.5160   -10.7984               7     8     2.2912   -0.14769E - 015               9    10    -0.87320  -9.59906              11    12     11.586    5.72817              13    14     19.104    16.9308              14    15    -0.34014E - 07                                -7.02599              15    16     8.3333    0.33458E - 067     9        13    16    -5.1858   -23.948______________________________________ 
    
     
                       TABLE 4______________________________________Surf.                                 Clear ApertureNo.  Type   Radius    Thickness                          Glass  Diameter______________________________________ 1   a      90.0535   10.00000 ACRYLIC                                 105.96 2   a      102.8973  15.78776        97.56 3   a      -70.2250  9.00000  ACRYLIC                                 97.45 4   a      -95.4074  0.50000         101.18 5          92.3723   27.00000 SK18   109.04 6          -642.6984 0.20000         106.50 7          158.4645  20.00000 SK18   98.88 8          -158.4645 0.06179         95.59 9          -157.2990 6.00000  SF6    95.5510          498.4189  6.57092         89.5511   a      -372.6684 9.00000  ACRYLIC                                 92.3512   a      -395.7785 1.50000         92.4113   a      172.5227  10.00000 ACRYLIC                                 92.4214   a      -445.8306 Space 1         94.0215   a      -59.4571  5.60000  ACRYLIC                                 99.7116          -60.5000  12.00000 430500 107.6317          ∞   14.00000 565500 180.0018          -600.0000 Image distance  180.00______________________________________Symbol Descriptiona - Polynomial asphereObject and Image Surface  Surface        Radius______________________________________  Image -599.9999______________________________________Even Polynomial AspheresSurf. No.  D             E          F______________________________________ 1     -9.4817E - 07 -1.0331E - 10                           -1.3133E - 13 2     -6.9575E - 07 -2.7955E - 10                            2.6820E - 14 3      2.3978E - 06 -8.0746E - 11                           -1.7129E - 14 4      2.2527E - 06 -2.4454E - 10                            3.9267E - 1411      1.8502E - 06 -1.5291E - 10                           -4.9911E - 1412      7.5312E - 07  9.9338E - 11                           -7.2778E - 1513     -1.3285E - 06 -3.6881E - 10                            4.5883E - 1314     -1.6576E - 07  4.4703E - 10                           -1.1777E - 1215     -2.0474E - 06  1.8685E - 09                           -1.0171E - 12______________________________________Surf. No.  G             H          I______________________________________ 1      7.7524E - 18  2.2028E - 20                           -3.9483E - 24 2      2.6395E - 17  1.2925E - 20                           -4.2776E - 24 3      2.2515E - 17  3.9252E - 21                           -3.6813E - 24 4     -8.9174E - 18 -7.2170E - 21                            1.0728E - 2411      1.1640E - 17  5.4479E - 21                           -1.8530E - 2412     -6.3377E - 18 -1.7516E - 21                           -2.6170E - 2413     -3.8744E - 16  1.6036E - 19                           -2.3489E - 2314      9.4904E - 16 -3.3734E - 19                            5.1496E - 2315      1.5162E - 16  6.1179E - 20                           -2.0252E - 23______________________________________Variable SpacesZoom    Space 1       Focal   ImagePos.    T(14)         Shift   Distance______________________________________1       40.761        0.936   0.0002       40.092        1.143   0.000______________________________________First-Order Data______________________________________f/number         1.17         1.16Magnification   -0.1035      -0.0931Object Height   -914.40      -1016.0Object Distance -1076.0      -1189.3Effective Focal Length            100.80       101.25Image Distance  -.37074E - 03                        -.44262E - 03Overall Length   1264.0       1376.6Forward Vertex Distance            187.98       187.31Barrel Length    187.98       187.31Stop Surface Number            5            5Distance to Stop            21.49        21.49Stop Diameter    107.586      107.618Entrance Pupil Distance            45.852       45.852Exit Pupil Distance           -80.038      -79.740______________________________________First Order Properties of ElementsElement SurfaceNumber Numbers         Power       f&#39;______________________________________ 1             1     2       0.86056E - 03                                  1162.0 2              3     4     -0.16366E - 02                                 -611.01 3              5     6      0.78262E - 02                                  127.78 4              7     8      0.78942E - 02                                  126.68 5              9    10     -0.68246E - 02                                 -146.53 6             11    12     -0.67408E - 04                                 -14835. 7             13    14      0.39484E - 02                                  253.27 8             15    16      0.11095E - 03                                  9013.3 9             16    17     -0.71074E - 02                                 -140.7010             17    18      0.94167E - 03                                  1061.9 8    10       15    18     -0.61289E - 02                                 -163.16______________________________________Element SurfaceNumber Numbers        lpp         l&#39;pp______________________________________ 1                         -37.330   -42.654 2              3     4    -19.052   -25.885 3              5     6     2.0973   -14.593 4              7     8     6.2468   -6.2468 5              9    10     0.79080  -2.5057 6             11    12    -111.51   -118.43 7             13    14     1.8778   -4.8526 8             15    16     275.78    280.62 9             16    17     0.27398E - 07                                -8.391610             17    18     8.9457   -0.23553E - 06 8    10       15    18    -3.8740   -25.497______________________________________ 
    
     
                       TABLE 5______________________________________Surf.                                 Clear ApertureNo.  Type   Radius    Thickness                          Glass  Diameter______________________________________1    a      118.1397  10.00000 ACRYLIC                                 105.092    a      138.7672  12.76842        97.783    a      -64.2610  9.00000  ACRYLIC                                 96.914    a      -87.7383  1.00000         94.285           87.6633   30.00000 SK18   103.106           -174.5638 0.30242         101.327           -168.9595 6.00000  SF6    101.268           261.3135  1.00000         97.539           95.6146   20.66778 SK5    96.9610          -260.0801 1.00000         96.1211   a      -730.9406 9.00000  ACRYLIC                                 94.2612   a      395.7578  4.82062         90.4513   a      114.6574  10.00000 ACRYLIC                                 90.8714   a      853.3167  Space 1         92.4415   a      -59.7301  5.60000  ACRYLIC                                 96.2116          -58.5000  12.00000 430500 105.2017          ∞   14.60000 565500 180.0018          -600.0000 Image distance  180.00______________________________________Symbol Descriptiona - Polynomial asphereObject and Image Surface  Surface        Radius______________________________________  Image -599.9999______________________________________Even Polynomial AspheresSurf. No.  D             E          F______________________________________ 1     -6.1424E - 07 -1.2999E - 10                           -1.1135E - 13 2     -5.5851E - 07 -3.4414E - 10                           -1.1712E - 15 3      2.7572E - 06 -1.7060E - 11                           -6.1786E - 14 4      2.5873E - 06  2.0009E - 11                            9.8026E - 1511      1.5098E - 06 -1.5395E - 10                            3.5089E - 1412      2.4066E - 07  2.0670E - 10                            5.5166E - 1413     -1.0005E - 06 -6.5093E - 10                            4.8030E - 1314      4.8019E - 07  3.0152E - 10                           -1.2475E - 1215     -2.2995E - 06  1.5448E - 09                           -9.4063E - 13______________________________________Surf. No.  G             H          I______________________________________ 1      8.7573E - 18  2.1148E - 20                           -3.9525E - 24 2      2.8706E - 17  1.5666E - 20                           -4.9291E - 24 3      1.6863E - 17  4.2845E - 21                           -2.1224E - 24 4     -2.9054E - 17 -2.1846E - 21                            1.4343E - 2411      2.1688E - 17 -1.6169E - 22                           -3.6426E - 2412      3.1063E - 17  1.0689E - 20                           -5.7969E - 2413     -3.5518E - 16  1.6480E - 19                           -2.4355E - 2314      9.6934E - 16 -3.2272E - 19                            4.3847E - 2315      1.7519E - 16  5.4265E - 20                           -2.5406E - 23______________________________________Variable SpacesZoom    Space 1       Focal   ImagePos.    T(14)         Shift   Distance______________________________________1       42.527        -0.300  0.0002       43.133        -0.584  0.000______________________________________First-Order Data______________________________________f/number         1.22         1.23Magnification   -0.0931      -0.1035Object Height   -1016.0      -914.40Object Distance -1194.7      -1080.6Effective Focal Length            101.87       101.46Image Distance  -.10580E - 03                        -.12529E - 03Overall Length   1385.0       1271.5Forward Vertex Distance            190.29       190.89Barrel Length    190.29       190.89Stop Surface Number            5            5Distance to Stop            24.86        24.86Stop Diameter    100.393      100.501Entrance Pupil Distance            44.371       44.371Exit Pupil Distance           -80.781      -81.051______________________________________First Order Properties of ElementsElement SurfaceNumber Numbers        Power       f&#39;______________________________________ 1             1     2      0.72085E - 03                                 1387.2 2              3     4    -0.17955E - 02                                -556.93 3              5     6     0.10498E - 01                                 95.259 4              7     8    -0.79691E - 02                                -125.49 5              9    10     0.82768E - 02                                 120.82 6             11    12    -0.19283E - 02                                -518.60 7             13    14     0.37446E - 02                                 267.05 8             15    16     0.43541E - 03                                 2296.7 9             16    17    -0.73504E - 02                                -136.0510             17    18     0.94167E - 03                                 1061.9 8    10       15    18    -0.60528E - 02                                -165.21______________________________________Element SurfaceNumber Numbers        lpp         l&#39;pp______________________________________ 1                         -33.045   -38.815 2              3     4    -18.884   -25.784 3              5     6     6.3964   -12.737 4              7     8     1.2917   -1.9978 5              9    10     3.5681   -9.7055 6             11    12     3.8984   -2.1107 7             13    14    -1.0345   -7.6991 8             15    16     72.674    71.177 9             16    17     0.24994E - 07                                -8.391610             17    18     9.3291    0.52548E - 06 8    10       15    18    -4.0041   -26.032______________________________________ 
    
     
                       TABLE 6______________________________________Ex.No.  f.sub.0 f.sub.1  f.sub.2                       fcr   f.sub.3                                   fp    1/2 w______________________________________1    76.68   511.00   67.32 -677.81                             -164.11                                   85.89 38.0°2    75.97   735.15   72.59 464.15                             -113.80                                   81.53 38.0°3    78.32   310.32   97.32 397.14                             -157.17                                   79.09 38.0°4    100.80  -1387.72 106.18                       255.53                             -163.16                                   127.78                                         39.3°5    101.46  -968.64  94.73 537.97                             -165.21                                   95.26 39.3°______________________________________