Digital laser image recorder including delay lines

• US 6,396,042 B1
• Filed: 10/19/1999
• Issued: 05/28/2002
• Est. Priority Date: 10/19/1999
• Status: Expired due to Fees

• Current Assignee: OL Security LLC (Intellectual Ventures LLC)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Boardman, John D., Gangstead, Mervin L.
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US09/421,444
• Time in Patent Office: 952 Days
• Field of Search: 250/208.1,201.5,578.1,216,566,236,570 347/255,256,259,231,238 369/179,132,116,121,103
• US Class Current: 250/208.1
• CPC Class Codes: G11B 7/0025 with cylinders or cylinder-like carriers or cylindrical sections or flat carriers loaded onto a cylindrical surface, e.g. truncated cones
• CPC Class Codes: G11B 7/0045 Recording G11B7/006, G11B7/0065 take precedence
• CPC Class Codes: G11B 7/0916 Foucault or knife-edge methods
• CPC Class Codes: G11B 7/12 Heads, e.g. forming of the optical beam spot or modulation of the optical beam disposition or mounting of head elements within housing or with provision for moving of light source, optical beam or detector, irrelevant to the transducing method G11B7/08 ; modulating lasers H01S3/10; controlling the intensity, colour, phase, polarisation or direction of light beams arriving from an independent light source, e.g. switching gating or modulating G02F1/00
• CPC Class Codes: G11B 7/126 Circuits, methods or arrangements for laser control or stabilisation
• CPC Class Codes: G11B 7/127 Lasers; Multiple laser arrays lasers per se H01S
• CPC Class Codes: G11B 7/1356 Double or multiple prisms, i.e. having two or more prisms in cooperation
• CPC Class Codes: G11B 7/1398 Means for shaping the cross-section of the beam, e.g. into circular or elliptical cross-section
• CPC Class Codes: G11B 7/14 specially adapted to record on, or to reproduce from, more than one track simultaneously

Abstract

The digital laser image recorder includes a data manipulation and control system which may provide digital data to a digital light source for conversion to an analog modulated light beam. A scanner may also be provided to direct the light beam toward a writing surface which may be disposed on the interior of a rotatable cylinder. A film handling device operable to deliver sheet film to the writing surface may also deliver sheet film from the writing surface to an associated output tray after writing. In another embodiment, beam shaping optics may be provided to convert the analog modulated light beams to collimated beams of a predetermined size and circular distribution. The beam shaping optics may also incorporate a power control filter to control the intensity of the collimated beams. In yet another embodiment, a shutter may be provided. The shutter may have a reflective surface with a first position in which the shutter reflects the light beams away from the scanner, and a second position in which the light beams strike the scanner. A photodiode may also be provided to measure the intensity of the reflected light beams. In still another embodiment, focusing optics may be provided to focus the collimated beams to form laser beams which may be directed toward the scanner.

Claims

1. A digital laser image recorder, comprising:

a digital light source;

a data manipulation and control system operable to produce a digital bit stream to the digital light source, the digital light source operable to convert the digital bit stream to an analog modulated light beam;

a transport having a rotatable cylinder with a writing surface disposed upon an interior surface of the rotatable cylinder; and

a scanner operable to direct the analog modulated light beams from the digital light source to the writing surface of the transport.

2. The digital laser image recorder of claim 1, wherein the digital light source comprises a plurality of laser diodes and wherein the analog modulated light beam is produced by selectively activating combinations of the plurality of laser diodes.

3. The digital laser image recorder of claim 1, wherein the digital light source produces a plurality of beams, the plurality of beams being adjusted into a single collinear beam.

4. The digital laser image recorder of claim 1, further comprising beam shaping optics to convert the analog modulated light beams to collimated beams of a predetermined size and circular distribution.

5. The digital laser image recorder of claim 4, wherein the beam shaping optics further comprises a power control filter to control the intensity of the collimated beams.

6. The digital laser image recorder of claim 1, further comprising a shutter having a first position in which a reflective surface associated with the shutter reflects the analog modulated light beams away from the scanner, and a second position in which the analog modulated light beams are allowed to strike the scanner.

7. The digital laser image recorder of claim 6, further comprising a photodiode for monitoring the intensity of the analog modulated light beams which are reflected by the shutter.

8. The digital laser image recorder of claim 4, further comprising focusing optics operable to focus the collimated beams to form focused laser beams which are directed toward the scanner.

9. The digital laser image recorder of claim 1, further comprising a film handling device operable to supply a sheet film to the writing surface.

10. The digital laser image recorder of claim 9, wherein the film handling device is operable to remove the sheet film from the writing surface and deliver the sheet film to an output tray.

11. The digital laser image recorder of claim 1, wherein the transport further comprises a vacuum operable to releasably attach a sheet film to the writing surface.

12. A digital laser image recorder, comprising:

a digital light source;

a data manipulation and control system producing a digital bitstream applied to the digital light source, the digital light source operating to convert the digital bitstream to an analog modulated light beam;

a transport having a rotatable cylinder with a writing surface disposed on an interior surface of the rotatable cylinder;

a shaft having a first reflect facet mounted thereon; and

a motor coupled to the shaft to rotate the shaft through at least partial revolutions.

13. The digital laser image recorder of claim 12, wherein the shaft comprises an air-bearing supporting shaft.

14. The digital laser image recorder of claim 12, wherein the reflective facet is coupled with the shaft at a 45°

angle with respect to a central axis of the shaft.

15. The digital laser image recorder of claim 12, further comprising a second reflective facet coupled with the shaft.

16. The digital laser image recorder of claim 12, wherein the motor further comprises a shaft encoder operable to measure the rotational speed of the motor.

17. The digital laser image recorder of claim 16 further comprising an electronic motor controller operable to receive information regarding the rotational speed of the motor from the shaft encoder and adjust the rotational speed of the motor based upon the information.

18. The digital laser image recorder of claim 12, wherein the shaft and facet continuously rotate through 360°

revolutions.

19. The digital laser image recorder of claim 12, wherein the digital laser image recorder comprises a galvanometer type scanner operable to rotate the shaft through less than 360°

in a first direction and rotate the shaft through less than 360°

in a second direction, opposite the first direction.

20. The digital laser image recorder of claim 12, wherein the facet further comprises a pentaprism operable to bend the light beam 90°

.

21. A digital laser image recorder, comprising:

a digital light source;

a data manipulation and control system producing a digital bitstream applied to the digital light source, the digital light source converting the digital bitstream to an analog modulated light beam;

a transport comprising;

a translation stage;

a translation cylinder slottably coupled with the translation stage and having an interior surface comprising a curved writing platen;

an image recording medium disposed on the interior surface of the translation cylinder; and

a scanner operable to direct the analog modulated light beams from the digital light source toward the curved writing platen.

22. The digital laser image recorder of claim 21, wherein the transport and the scanner advance one line width, relative to the scanner, for each revolution of the scanner, in a direction parallel to the central axis of the cylinder.

23. The digital laser image recorder of claim 21, wherein the line width is approximately equal to four and two tenths microns.

24. The digital laser image recorder of claim 21, wherein a vacuum removably couples the sheet of film with the writing platen.

25. The digital laser image recorder of claim 21, wherein static electricity removably couples the sheet of film with the writing platen.

26. The digital laser image recorder of claim 21, further comprising a line start detector operable to produce an electrical pulse in response to the passage of the beam of light over a knife edge, the line start detector and the knife edge coupled with the translational cylinder.

27. The digital laser image recorder of claim 21, further comprising a collimating lens coupled with the translational cylinder between the knife edge and the detector and operable to collimate the beam of light to maintain a constant diameter of the beam to facilitate precise measurement of the beam by the detector.

28. A digital laser image recorder, comprising:

a digital light source;

a data manipulation and control system producing a digital bitstream applied to the digital light source, the digital light source converting the digital bitstream to an analog modulated light beam;

a transport having a rotatable cylinder with a writing surface disposed on an interior surface of the rotatable cylinder;

a scanner operable to direct the analog modulated light beams from the digital light source to the writing surface of the transport, the scanner comprising a beam combiner having a reflecting mirror with a plurality of facets thereon, the facets each disposed at different angles with respect to a central axis of the beam combiner; and

the facets reflecting the light beams parallel to an optical axis associated with a receiving lens.

29. A light source for a laser image recording device, comprising:

a plurality of laser driven diodes converting digital data to analog modulated light beams;

digitally-programmable delay lines associated with the laser driven diodes to delay a pulse received by the delay line for a predetermined time increment corresponding to a digital word input received by the delay line; and

a plurality of beam splitters, each beam splitter corresponding with at least one of the laser driven diodes.

30. The light source of claim 29, further comprising:

a plurality of horizontal Risley prism pairs and a plurality of vertical Risley prism pairs, each horizontal Risley prism pair and vertical Risley prism pair corresponding to at least one of the laser driven diodes;

each horizontal Risley prism pair and each vertical Risley prism pair incorporating at least two Risley prisms;

each horizontal Risley prism pair operable to adjust the light beams along first axes;

each vertical Risley prism pair operable to adjust the light beams along second axes, orthogonal to the first axes; and

a mechanical drive operable to rotate the horizontal and vertical Risley prisms in a predetermined sequence.