Illuminator optical assembly for an analytical instrument and methods of alignment and manufacture

• US 6,042,249 A
• Filed: 07/30/1996
• Issued: 03/28/2000
• Est. Priority Date: 07/30/1996
• Status: Expired due to Fees

• Current Assignee: Bayer Corporation (Bayer AG)
• Original Assignee: Bayer Corporation (Bayer AG)
• Inventors: Spangenberg, Peter
• Primary Examiner(s): HUSAR, STEPHEN F
• Application Number:
  US08/688,559
• Time in Patent Office: 1,337 Days
• Field of Search: 362/89, 362/259, 362/268, 362/277, 362/319, 362/293
• US Class Current: 362/259
• CPC Class Codes: G01N 15/14 Optical investigation techniques, e.g. flow cytometry
• CPC Class Codes: G01N 2201/0633 Directed, collimated illumination

Abstract

An optical illuminator assembly for an analytical instrument, such as a clinical hematology or a flow cytometer instrument, and method of aligning the components of the illuminator assembly. The illuminator assembly includes a plurality of optical components, such as a laser source, e.g., a laser diode, optionally a spatial filter, a beam shaping aperture, and a focussing lens. The optical components are mounted in mounting plates, frames or mounting cylinders, which are in turn coupled to a mounting surface on the assembly. Each of the mounting plates or frames is movable in the x and y directions, perpendicular to the laser beam, by micrometer adjusters having opposing spring plungers or the like, to decenter components in the desired laser beam path of the illuminator assembly. The micrometers and spring plungers are removably secured in the mounting surface so that after the x-y alignment, the mounting plates or frames can be secured to the mounting surface by, e.g., screws, and the micrometers and spring plungers are removed. The beam focussing lenses are similarly mounted in mounting cylinders and adjusted in the z direction of the beam path (focused) by removably mounted adjusters, such as eccentric focussing tools. After focussing, the focusing tools are removed. Thus, a factory alignment and a low cost prealigned optical illuminator assembly is obtained.

Claims

1. An illuminator optical assembly for providing a shaped, filtered beam in an analytical instrument, the assembly having a laser source having a laser beam output, a lens and a masking aperture, the assembly further comprising:

a housing having a plate mounting surface;

a component mounting plate having an oversized mounting hole and having a central bore in alignment with said beam;

a locking screw installed through said oversized mounting hole into a threaded hole in said mounting surface;

a first micrometer adjuster and a first spring plunger removably mounted in said housing in opposition, the first micrometer adjuster contacting a first edge of said component mounting plate for positioning said plate on said mounting surface;

a second micrometer adjuster and a second spring plunger removably mounted in said housing in opposition, the second micrometer adjuster contacting a second edge of said component mounting plate for positioning said plate on said mounting surface, the first and second edges being in orthoganol axes.

wherein one of said laser source, said lens and said masking aperture is said component mounted in said central bore of said mounting plate.

2. The apparatus of claim 1 wherein said component is said lens, said plate mounting surface comprise a second bore, said mounting plate has a cylindrical periphery and further comprises a groove in said periphery, said apparatus further comprising an eccentric engaging pin connected to said plate mounting surface and engaging said groove, and an eccentric focusing cool removably mounted in said second bore, wherein said eccentric focusing tool is rotatable and coupled to said eccentric engaging pin to revolve said eccentric engaging pin in said groove, thereby positioning said lens.

3. The apparatus of claim 1, wherein said component mounted in the central bore of said mounting plate is said laser source, and further comprising:

a carrier having a central bore;

a mounting cylinder having a bore, a periphery, and a groove in the periphery, the mounting cylinder being fitted to said carrier central bore;

a second bore in said carrier;

an eccentric focusing tool removably mounted in said carrier second bore, said eccentric focusing tool having an eccentric engaging pin engaged with said mounting cylinder groove and having an axis of rotation, wherein rotation of the focusing tool shifts the lens in a plane normal to said axis of rotation; and

a locking screw operable to lock said mounting disk in place relative to said carrier.

4. The apparatus of claim 3 wherein said lens is mounted in said mounting cylinder bore and confined to motion in a linear path aligned with said beam.

5. The apparatus of claim 4 further comprising:

a second plate mounting surface in said housing;

a second component mounting plate having an oversized mounting hole and having a central bore in alignment with said beam;

a second locking screw installed through said oversized mounting hole into a threaded hole in said second mounting surface; and

a third and fourth micrometer adjuster and a corresponding third and fourth spring plunger removably mounted in respective opposition in said housing and contacting respectively a first edge and a second edge of said second component mounting plate for positioning said second plate on said second mounting surface, said first and second edges being in orthoganol axes;

wherein said aperture is mounted in said central bore of said second mounting plate.

6. An illuminator optical assembly for providing a shaped, filtered beam in an analytical instrument, the assembly having a laser source having a laser beam output, a lens and a masking aperture, the assembly further comprising:

a component mounting plate having an oversized mounting hole and having a central bore in alignment with said beam;

a housing having a plate mounting surface and a receptacle shaped to receive removably a micrometer adjuster to contact an edge of said component mounting plate and position said plate on said mounting surface; and

a locking screw operable to lock said oversized mounting hole to said mounting surface;

wherein one of said laser source, said lens and said masking aperture is said component mounted in said central bore of said mounting plate.

7. The apparatus of claim 6 wherein said component is said lens, said mounting plate has a cylindrical periphery and a groove in said periphery, an eccentric engaging pin connected to said plate mounting surface and engaging said groove, and said plate mounting surface further comprises a second bore, the second bore shaped to receive removably an eccentric focusing tool to couple to said eccentric engaging pin to revolve said eccentric engaging pin in said groove, thereby to position said lens.

8. The apparatus of claim 6 wherein said component mounted in the central bore of said mounting plate is said laser source, and further comprising:

a carrier having a central bore;

a mounting cylinder having a bore, a periphery, and a groove in the periphery, the mounting cylinder being fitted to said carrier central bore;

a lens mounted in said mounting cylinder bore;

a second bore in said carrier, the second bore being shaped to receive removably an eccentric focusing tool having an eccentric engaging pin to engage said groove periphery, wherein rotation of the focusing tool shifts the lens in a plane normal to said axis of rotation; and

a locking screw operable to lock said mounting cylinder in place relative to said carrier.

9. The apparatus of claim 8 wherein said lens is mounted in said bore and confined to motion in a linear path aligned with said beam.

10. The apparatus of claim 9 further comprising:

a second plate mounting surface in said housing;

a second component mounting plate having an oversized mounting hole and having a central bore in alignment with said beam;

a second locking screw operable to lock said oversized mounting hole to said second mounting surface; and

wherein the housing further comprises a second receptacle shaped to receive removably a second micrometer adjuster to contact an edge of said second component mounting plate to position said second plate on said second mounting surface;

wherein said lens is mounted in said central bore of said second mounting plate.

11. A method of assembling an illuminator optical assembly having a plurality of optical components and a laser beam path for an analytical instrument comprising the steps of:

a) mounting at least one of said plurality of components of the illuminator optical assembly on a first mounting plate, the first mounting plate having an aperture for receiving the component;

b) coupling the first mounting plate to a plate mounting surface at a first location for relative movement therewith with the first mounting plate aperture in said laser beam path;

c) inserting a micrometer adjuster into a hole on the first mounting plate;

d) operating the micrometer adjuster to adjust the one component to a second location, the second location corresponding to an aligned orientation relative to the beam path;

e) securing the first mounting plate to the plate mounting surface to fix the component at the aligned orientation;

f) removing the micrometer adjuster from the first mounting plate;

wherein the laser beam path is in a z axis, the method further comprising performing steps (a)-(f) to align the one optical component in an x direction; and

performing steps (a)-(f) to align the one optical component in a y direction using a second hole in which a second micrometer adjuster is removably inserted and operated to shift said component in the y direction.

12. The method of claim 11 further comprising the step of aligning the illuminator optical assembly by performing steps (a)-(f) for each of said plurality of optical components.

13. An illuminator optical assembly wherein the plurality of optical components comprises a laser source having a laser beam output and an aperture aligned relative to said laser beam path by the method of claim 12.

14. The method of claim 11, wherein said plurality of optical components includes a first lens having a focal point, the method further comprising:

g) mounting the first lens in a mounting cylinder having a periphery;

h) providing the mounting cylinder with a groove in the periphery;

i) mounting the mounting cylinder in a carrier having a bore which permits the mounting cylinder to move in a direction parallel to the laser beam path;

j) mounting an eccentric focusing tool in the carrier to engage the peripheral groove of the mounting cylinder;

k) actuating the focusing tool to move the mounting cylinder relative to the carrier, thereby to adjust the lens focal point in the direction of the laser;

l) securing the mounting cylinder disk to the carrier to fix in place the lens; and

m) removing the focusing tool from the carrier.

15. The method of claim 14, wherein said plurality of optical components further comprises a second lens, the method further comprising performing steps g)-m) to focus said second lens.

16. The method of claim 15 wherein said first and second lens further comprise a portion of spatial filter and the plurality of optical components further comprise a laser diode wherein the method further comprises providing a spatially filtered laser beam.

17. An illuminator optical assembly comprising a laser diode, a spatial filter having at least a first lens and a second lens, and a filter aperture, wherein each of said laser diode, and aperture are aligned by the method of claim 11.

18. The method of claim 11 wherein steps c), d), e) and f) further comprise inserting at least two micrometer adjusters into a like number of holes on the first mounting plate, inserting two spring plungers into a like number of holes in respective opposition to said two micrometer adjustors, operating each of said micrometers to orient the component to the aligned orientation, securing the first mounting plate to the plate mounting surface, and removing each of the micrometer adjusters and spring plungers after performing step e).

19. The method of claim 18 further comprising performing steps a)-d) to decenter selected ones of the plurality of optical components and thereafter performing steps e) and f), and providing an illuminator assembly having aligned optical components.

20. The method of claim 19 further comprising performing steps a)-f) at a factory and delivering prealigned illuminator assemblies for installation in a flow cytometer instrument.

21. The method of claim 18 further comprising performing steps a)-f) for selected ones of the plurality of optical components wherein each of the selected components is aligned along a predetermined beam axis.

22. The method of claim 11 wherein step a) further comprises mounting a laser diode in the first mounting plate and step d) further comprises adjusting the laser source so that it emits a laser beam output on the beam path.

23. The method of claim 11 wherein step a) further comprises mounting a mask having a first aperture on a plate having a second aperture, and mounting the plate in the first mounting plate, and step d) further comprises adjusting the mask relative to the laser beam path to operate on said laser beam.

24. An illuminator optical assembly comprising a laser diode, a spatial filter having at least a first lens and a second lens, and a filter aperture, wherein each of the first and second lens is aligned by the method of claim 16.

25. An illuminator optical assembly for providing a shaped, filtered beam in an analytical instrument, the assembly having a laser source having a laser beam output, a lens and a masking aperture, the assembly further comprising:

a housing having a plate mounting surface;

a component mounting plate having at least three oversized mounting holes and having a central bore in alignment with said beam;

at least three locking screws respectively installed through said oversized mounting holes into at least three threaded holes in said mounting surface;

a first micrometer adjuster removably mounted in said housing in contact with an edge of said component mounting plate for positioning said plate on said mounting surface before tightening said mounting screws;

a first spring plunger assembly removably mounted on the housing diametrically opposite the first micrometer adjuster to provide a bias force upon the mounting plate to urge the mounting plate in contact with the micrometer adjuster to adjust the mounting plate in a first direction;

a second micrometer adjuster and a second spring plunger mounted to the housing in diametric opposite and perpendicular to the first micrometer adjuster and first spring plunger to adjust the mounting plate in a second direction orthogonal to the first direction;

a plurality of spring and flat washers interposed between the locking screws and the mounting plate to ensure that the mounting plate remains in sliding contact with the plate mounting surface for alignment, the locking screws having a slightly loosened state prior to adjustment so that the spring washers maintain contact between the mounting plate and mounting surface but do not impede alignment, the screws also having a tightened state to flatten the spring washers and lock the assembly in place; and

wherein one of said laser source, said lens and said masking aperture is said component mounted in said central bore of said mounting plate.

26. The apparatus of claim 25 wherein at least one of the plate mounting surface and the mounting surface of the mounting plate is treated with a low friction surface finish such as teflon impregnated anodize in order to minimize static sliding friction and to facilitate ease of precise alignment positioning.

27. The apparatus of claim 25 wherein said component is said lens, said plate mounting surface further comprises a second bore, said mounting plate has a cylindrical periphery and further comprises a groove in said periphery, said apparatus further comprising an eccentric engaging pin connected to said plate mounting surface and engaging said groove, and an eccentric focusing tool removably mounted in said second bore, wherein said eccentric focusing tool is rotatable and coupled to said eccentric engaging pin to revolve said eccentric engaging pin in said groove, thereby positioning said lens.

28. The apparatus of claim 25, wherein said component mounted in the central bore of said mounting plate is said laser source, and further comprising:

a carrier having a central bore;

a mounting cylinder having a bore, a periphery, and a groove in the periphery, the mounting cylinder being fitted to said carrier central bore;

a second bore in said carrier;

an eccentric focusing tool removably mounted in said carrier second bore, said eccentric focusing tool having an eccentric engaging pin engaged with said mounting cylinder groove and having an axis of rotation, wherein rotation of the focusing tool shifts the lens in a plane normal to said axis of rotation; and

a locking screw operable to lock said mounting cylinder in place relative to said carrier.

29. The apparatus of claim 28 wherein said lens is mounted in said bore and confined to motion in a linear path aligned with said beam.

30. The apparatus of claim 29 further comprising:

a second plate mounting surface in said housing;

a second component mounting plate having an oversized mounting hole and having a central bore in alignment with said beam;

second locking screw installed through said oversized mounting hole into a threaded hole in said second mounting surface; and

a second micrometer adjuster removably mounted in said housing and contacting an edge of said second component mounting plate for positioning said second plate on said second mounting surface;

wherein said lens is mounted in said central bore of said second mounting plate.