Optical scanner system having a laser beam power attentuation mechanism

• US 6,108,025 A
• Filed: 09/29/1997
• Issued: 08/22/2000
• Est. Priority Date: 09/29/1997
• Status: Expired due to Fees

• Current Assignee: CareStream Health Incorporated
• Original Assignee: Eastman Kodak Company
• Inventors: Schubert, Paul C., Li, Yun Zhong
• Primary Examiner(s): Le, N.
• Assistant Examiner(s): PHAM, HAI CHI
• Application Number:
  US08/939,899
• Time in Patent Office: 1,058 Days
• Field of Search: 347/241, 347/256, 347/244, 347/258, 347/260, 355/67, 355/68, 355/71, 355/88, 355/117, 345/418, 356/218, 359/205, 359/207, 359/212
• US Class Current: 347/256
• CPC Class Codes: H04N 1/036 for optical reproduction
• CPC Class Codes: H04N 1/40037 the reproducing element being a laser

Abstract

An optical scanner assembly for exposing an image on a scanned surface. The optical scanner assembly includes a laser mechanism for producing a laser beam representative of the image to be exposed on the scanned surface. The laser beam defines an optical path between the laser mechanism and the scanned surface. A laser beam shaping system is positioned along the optical path for focusing and shaping the laser beam onto the scanned surface. A scanning and directing system is provided for directing the laser beam to the scanned surface and scanning the laser beam across the scanned surface in an image-wise pattern. A unibody attenuation mechanism is positioned along the optical path for power attenuation of the laser beam, wherein the unibody variable density power attenuation mechanism is a linear density wedge.

Claims

1. An optical scanner assembly for exposing an image on a scanned surface, the optical scanner assembly comprising:

a laser mechanism for producing a modulated laser beam representative of the image to be exposed on the scanned surface, the laser beam defining an optical path between the laser mechanism and the scanned surface;

a laser beam shaping system positioned along said optical path for focusing and shaping the laser beam onto the scanned surface;

a scanning and directing system positioned along said optical path for directing the laser beam to the scanned surface and scanning the laser beam across the scanned surface in an image-wise pattern;

a single unibody variable density attenuation mechanism positioned along said optical path for power attenuation of the laser beam along a single polarization axis which is shifted laterally of said optical path, wherein the unibody attenuation mechanism is a linear density wedge; and

an optical device for correcting said lateral shift of said laser beam.

2. The optical scanner assembly of claim 1, wherein the laser beam shaping system includes:

a first cylinder lens positioned along the optical path for shaping and focusing the laser beam in a first direction; and

a second cylinder lens having a longitudinal axis extending therethrough, positioned along the optical path for shaping and focusing the laser beam in a second direction;

wherein the unibody attenuation mechanism has a density gradient which is oriented perpendicular to the longitudinal axis of the second cylinder lens.

3. The optical scanner assembly of claim 2, wherein the unibody attenuation mechanism is located between the laser mechanism and the second cylinder lens.

4. The optical scanner assembly of claim 2, wherein the second cylinder lens has a focusing spot at the scanned surface, and wherein the combination of the unibody attenuation mechanism and the second cylinder lens operate to maintain the size, shape and position of the focusing spot at the scanned surface.

5. The optical scanner assembly of claim 1, further wherein the unibody attenuation mechanism is movable along an axis perpendicular to said optical path.

6. The optical scanner assembly of claim 1, further comprising an adjustment mechanism coupled to the unibody attenuation mechanism for adjusting an amount of power attenuation of the laser beam.

7. The optical scanner assembly of claim 6, wherein the adjustment mechanism for adjusting the unibody attenuation mechanism adjusts a position of the unibody attenuation mechanism in a direction perpendicular to the optical path.

8. The optical scanner assembly of claim 6, wherein the adjustment mechanism for adjusting the unibody attenuation mechanism includes a linear actuator.

9. The optical scanner assembly of claim 1, wherein the unibody attenuation mechanism has a first end and a second end, wherein a degree of attenuation varies between the first end and the second end.

10. The optical scanner assembly of claim 9, wherein the unibody attenuation mechanism is positioned substantially perpendicular to the optical path having the laser beam passing therethrough, and wherein the attenuation of the laser beam power increases as the attenuation mechanism is moved from a position proximate the first end to a position proximate the second end.

11. The optical scanner assembly of claim 1, wherein the unibody attenuation mechanism includes a first side and a second side, and wherein the unibody attenuation mechanism shifts a position of the laser beam as it passes through the unibody attenuation mechanism from the first side to the second side.

12. The optical scanner assembly of claim 1, wherein the unibody attenuation mechanism further comprises:

an attenuator support substrate having a major surface; and

a varying reflective material covering the major surface.

13. The optical scanner assembly of claim 12, wherein the support substrate is constructed of glass.

14. The optical scanner assembly of claim 12, wherein the varying reflective material is a metallic material.

15. The optical scanner assembly of claim 12, wherein the attenuator support substrate includes a first end and a second end, and wherein a reflectivity density of the varying reflective material increases from the first end to the second end.

16. The optical scanner assembly of claim 12, wherein the unibody attenuation mechanism is partially transmissive, and wherein the attenuator support substrate includes a first end and a second end, and wherein the transmissive properties of the varying reflective material decrease from the first end to the second end.

17. An optical scanner assembly used in an internal drum type scanner, for exposing an image on a photosensitive film, the optical scanner assembly comprising:

a laser mechanism for producing a modulated laser beam representative of the image to be exposed on the photosensitive film, the laser beam defining an optical path between the laser mechanism and the photosensitive film;

a laser beam shaping system positioned along said optical path for focusing and shaping the laser beam;

a scanning and directing system positioned along said optical path for directing the laser beam and scanning the laser beam radially across the photosensitive film in an image-wise pattern;

a single variable density unibody attenuation mechanism having a first end and a second end, wherein a degree of density varies from the first end to the second end, and wherein the unibody attenuation mechanism is positioned along the optical path for power attenuation of the laser beam along a single polarization axis and for laterally shifting said laser beam relating to said optical path; and

an optical device for correcting said lateral shift of said laser beam.

18. The optical scanner assembly of claim 17, further wherein the unibody attenuation mechanism is adjustable.

19. The optical scanner assembly claim 17, wherein an optical density of the unibody attenuation mechanism increases proportionally to a distance across the unibody attenuation mechanism between the first end and the second end.

20. The optical scanner assembly of claim 19, wherein the unibody attenuation mechanism is positioned substantially perpendicular to the optical path having the laser beam passing therethrough, and wherein the attenuation of the laser beam increases as the laser beam is moved from a position proximate the first end to a position proximate the second end.

21. The optical scanner assembly of claim 17, wherein the unibody attenuation mechanism includes a first side and a second side, and wherein the unibody attenuation mechanism shifts a position of the laser beam as it passes through the unibody mechanism from the first side to the second side.

22. The optical scanner assembly of claim 17, wherein the unibody attenuation mechanism further comprises:

an attenuator support substrate having a major surface; and

a varying reflective material covering the major surface.

23. The optical scanner assembly of claim 22, wherein the support substrate is constructed of glass.

24. The optical scanner assembly of claim 22, wherein the varying reflective material is a metallic material.

25. The optical scanner assembly of claim 22, wherein the unibody attenuation mechanism is partially transmissive, and wherein the attenuator support substrate includes a first end and a second end, and wherein the transmissive properties of the varying reflective material decrease from the first end to the second end.

26. A laser imaging system comprising:

a film feed mechanism;

a film exposure mechanism;

a film processor mechanism;

a film receiving area; and

a film transport system for moving a piece of photosensitive film between the film feed mechanism, the film exposure mechanism, the film processor mechanism, and the film receiving area;

wherein the film exposure mechanism includes an optical scanner assembly having a single unibody attenuation mechanism for power attenuation of a laser beam passing therethrough, wherein the single unibody attenuation mechanism is a linear density wedge.

27. The laser imaging system of claim 26, wherein the optical scanner assembly is an internal drum type scanner.