Telecentric and achromatic f-theta scan lens system and method of use

Claim 2

A color corrected, diffraction limited, telecentric f-theta lens comprising, in succession from the incident side: a first meniscus lens concave to the incident side; a first bi-concave lens; a second meniscus lens convex to the incident side; a third meniscus lens concave to the incident side; a first bi-convex lenses; a second bi-convex lens and a second bi-concave lens; a first plane parallel surface glass plate.

Claim 3

The color corrected telecentric lens of claim 1, further comprising air spaces between all adjacent lens surfaces.

Claim 4

The color corrected telecentric lens of claim 1 wherein spacing between said first bi-convex lens, second meniscus lens and third meniscus lens is determined by edge contact between said first bi-convex lens, second meniscus lens and third meniscus lens.

Claim 5

The color corrected telecentric lens of claim 1 wherein spacing between said second bi-concave lens and second said bi-convex lens is determined by edge contact between said bi-concave lens and said bi-convex lens.

Claim 6

The color corrected telecentric lens of claim 1, wherein said individual lenses are coated with an anti-reflection coating.

Claim 7

The color corrected telecentric lens of claim 1, wherein said lenses are enclosed in a housing comprised of stainless steel.

Claim 8

A color corrected telecentric lens comprising: seven air spaced lens elements with numerical characteristics substantially as follows: ______________________________________ SURFACE RADIUS- CLR. LENS # # MM SEPN-MM DIAM.-MM ______________________________________ S1 -98.600 90.00 L1 20.000 S2 -173.440 120.00 0.500 S3 -4068.600 180.00 L2 15.000 S4 442.180 160.00 6.000 S5 2384.400 180.00 L3 22.000 S6 315.700 137.70 10.000 S7 -989.380 137.70 L4 30.000 S8 -233.540 180.00 2.500 S9 282.210 180.00 L5 40.000 S10 -233.540 180.00 21.690 S11 289.870 180.00 L6 40.000 S12 -289.870 180.00 2.500 S13 -233.540 150.00 L7 20.000 S14 205.980 150.00 ______________________________________ Said above lens elements arranged as indicated at least one optical element of BK7 glass having parallel surfaces disposed to provide a total element glass thickness of 40 mm whereby said telecentric lens possesses the following characteristics: Effective Focal Length 250 mm; Color Corrected For Wavelengths in the range encompassing 532, 514.5 and 488 nm; Telecentricity<6 minutes of arc; Numerical Aperature=0.05 or=F/10; Color Magnification Difference: <3 microns deviation between the relative spot locations on the image plane for spots of Argon Blue and frequency doubled YAG light; <5 microns deviation between the relative spot locations on the image plane for spots of Argon Green and frequency doubled YAG light; Calibrated Focal Length 248.948 mm; Total Scan Length 100 nm; Scan Angle=±11.5 degrees; Diffraction Limited Image Quality Over the Scan Angle and Wavelength Range; wherein: said lens number designates the lens element progressing sequentially from the incident side; surface number designates surfaces of the lens elements progressing sequentially from the incident side; SEPN is the separation distance from one surface Sn to Sn+1 and the CLR DIAM is the clear diameter of the lens at the corresponding surface.

Claim 9

A color corrected telecentric lens comprising: seven air spaced lens elements with numerical characteristics substantially as follows: ______________________________________ SURFACE RADIUS- CLR. LENS # # MM SEPN-MM DIAM.-MM ______________________________________ S1 -98.600 90.00 L1 20.000 S2 -173.440 120.00 0.500 S3 -4068.600 180.00 L2 15.000 S4 442.180 160.00 6.000 S5 2384.400 180.00 L3 22.000 S6 315.700 137.70 10.000 S7 -989.380 137.70 L4 30.000 S8 -233.540 180.00 2.500 S9 282.210 180.00 L5 40.000 S10 -233.540 180.00 21.690 S11 289.870 180.00 L6 40.000 S12 -289.870 180.00 2.500 S13 -233.540 150.00 L7 20.000 S14 205.980 150.00 ______________________________________ Said above lens elements arranged as indicated at least one optical element of BK7 glass having parallel surfaces disposed to provide a total element glass thickness of 40 mm whereby said telecentric lens possesses the following characteristics: Effective Focal Length 250 mm; Color Corrected For Wavelengths in the range encompassing 532, 514.5 and 488 nm; Telecentricity<6 minutes of arc; Numerical Aperature=0.05 or=F/10; Color Magnification Difference: <3 microns deviation between the relative spot locations on the image plane for spots of Argon Blue and frequency doubled YAG light; <5 microns deviation between the relative spot locations on the image plane for spots of Argon Green and frequency doubled YAG light; Calibrated Focal Length 248.948 mm; Total Scan Length 100 nm; Scan Angle=±11.5 degrees; Diffraction Limited Image Quality Over the Scan Angle and Wavelength Range; wherein: said lens number designates the lens element progressing sequentially from the incident side; surface number designates surfaces of the lens elements progressing sequentially from the incident side; SEPN is the separation distance from one surface Sn to Sn+1 and the CLR DIAM is the clear diameter of the lens at the corresponding surface.

Claim 10

The color corrected telecentric lens of claim 7 further including a beam splitter formed of at least an optical element having at least one pair of parallel surfaces disposed to provide a total element thickness of 40 mm, disposed intermediate said lens element L7 and an image plane of said lens.

Claim 11

The color corrected telecentric lens of claim 7 comprising said seven air spaced lens elements and said parallel plate beam splitter of 40 mm total glass thickness, said lens elements being fabricated of glasses as follows: lens L1 of a glass designated F5; lens L2 of a glass designated PSK52; lens L3 of a glass designated BaF4; lenses L4, L5 and L6 of a glass designated LaK8; lens L7 of a glass designated SF1; and beam splitter of a glass designated BK7.

Claim 12

The lens of claim 8 wherein said parallel surface beam splitter comprises at least two elements cemented together forming said beam splitter.

Claim 13

The color corrected telecentric lens of claim 8 wherein said individual lens elements are coated with an anti-reflection coating.

Claim 14

The lens of claim 8 enclosed in a housing comprised of stainless steel.

Claim 17

The method of claim 13 wherein said steps of providing a lens assembly includes providing said lenses where said lenses, in order, meet the following requirements: ______________________________________ SURFACE RADIUS- CLR. LENS # # MM SEPN-MM DIAM.-MM ______________________________________ S1 -98.600 90.00 L1 20.000 S2 -173.440 120.00 0.500 S3 -4068.600 180.00 L2 15.000 S4 442.180 160.00 6.000 S5 2384.400 180.00 L3 22.000 S6 315.700 137.70 10.000 S7 -989.380 137.70 L4 30.000 S8 -233.540 180.00 2.500 S9 282.210 180.00 L5 40.000 S10 -233.540 180.00 21.690 S11 289.870 180.00 L6 40.000 S12 -289.870 180.00 2.500 S13 -233.540 150.00 L7 20.000 S14 205.980 150.00 ______________________________________ Said above lens elements arranged as indicated at least one wherein: said lens number designates the lens element progressing sequentially from the incident side; surface number designates surfaces of the lens elements progressing sequentially from the incident side; SEPN is the separation distance from one surface Sn to Sn+1 and the CLR DIAM is the clear diameter of the lens at the corresponding surface.

Claim 18

The method of claim 13, wherein said individual lenses are coated with an anti-reflection coating.

Claim 19

The method of claim 13, wherein said lenses are enclosed in a housing comprised of stainless steel.