Pancratic condenser for projectors

Claim 1

IN A LIGHT CONDENSER, A ZOOM TYPE OF PANCRATIC OPTICAL SYSTEM WHICH FORMS AN IMAGE OF A LIGHT SOURCE AT VARIOUS CONTINUOUS MAGNIFICATIONS WITHIN A MAGNIFICATION RANGE OF AT LEAST 2.0, SAID SYSTEM COMPRISING A PLURALITY OF OPTICALLY ALIGNED AXIALLY SPACED LENS MEMBERS WHICH ARE, A DOUBLE CONCAVE LENS MEMBER DESIGNATED I LOCATED ON THE EXIT SIDE OF SAID SYSTEM FARTHEST FROM SAID SOURCE, THE SURFACE OF STRONGEST CURVATURE BEING ON THE EXIT SIDE THEREOF, A SYMMETRICAL SECOND LENS MEMBER LOCATED ON THE ENTRANT SIDE OF LENS MEMBER I AND COMPOSED OF TWO SIMILAR POSITIVE LENSES WHICH ARE DESIGNATED II AND III AND HAVE DUPLICATE CONVEX SURFACES FACING AND SEPARATED FROM EACH OTHER, SAID SECOND MEMBER BEING MOVABLY MOUNTED FOR AXIAL MOTION AS A UNIT TO VARY SAID MAGNIFICATION, A DOUBLE CONCAVE LENS MEMBER DESIGNATED IV LOCATED ON THE ENTRANT SIDE OF SAID SECOND LENS MEMBER AND HAVING THE SURFACE OF STRONGEST CURVATURE LYING ON THE ENTRANT SIDE OF MEMBER IV, A DOUBLE CONVEX COMPOUND LENS MEMBER LOCATED ON THE ENTRANT SIDE OF MEMBER IV AND COMPRISING A REAR DOUBLE CONVEX LENS ELEMENT V WHICH CONTACTS THE CONCAVE SIDE OF A CONVEX-CONCAVO LENS ELEMENT VI, AND A FOREMOST POSITIVE MENISCUS LENS MEMBER DESIGNATED VII AND HAVING ITS SURFACE OF STRONGEST CURVATURE FACING REARWARDLY, THE SPECIFIC VALUES IN TERMS OF FA FOR THE OPTICAL PARAMETERS BEING SUBSTANTIALLY AS GIVEN IN THE TABLE HEREBELOW WHEREIN FA REPRESENTS THE EQUIVALENT FOCAL LENGTH OF LENS ELEMENTS V, VI AND VII COLLECTIVELY, -FI TO -FVI DESIGNATE THE EQUIVALENT FOCAL LENGTHS OF THE SUCCESSIVE LENS PARTS, THE MINUS (-) SIGN MEANING NEGATIVE FOCAL LENGTH, S1 TO S6 REPRESENTING THE SUCCESSIVE AXIAL AIR SPACES, T1 TO T7 REPRESENTING THE SUCCESSIVE AXIAL LENS THICKNESS, AND ND AND V REPRESENTING RESPECTIVELY THE REFRACTIVE INDEX ADN ABBE NUMBER OF THE GLASSES IN THE LENSES INDICATED. PS@ -FI=2.423 FA T1=.165 FA F(II, III)=1.724 FA T2=.228 FA -FIV=2.505 FA T3=.228 FA F(V, VI)=2.128 FA T4=.1033 FA FVII=1.296 FA T5=.474 FA FVII=FIII=3.448 FA T6=.1053 FA FV=.974 FA T7=.292 FA -FVI=1.439 FA ND (I)=1.657 S1=.3062 FA (HIGH M) ND (II)=ND (III)=1.670 S1=.928 FA (INTERMEDIATE ND (IV)=1.649 M) ND (V)=1.517 S1=1.544 FA (LOW M) ND (VI)=1.751 S2=.00205 FA ND (VII)=1.517 S3=1.262 FA (HIGH M) V (I)=36.6 S3=.6425 FA (INTEMEDI- V (II)=V (III)=47.2 ATE M) V (IV)=33.8 S3=0.207 FA (LOW M) V (V)=64.5 S4=.0205 FA V (VI)=27.8 S5=.2238 FA V (VII)=64.5 S6=.556 FA