Claims
- 1. A method for determining the location of an edge of an imaging media, the method comprising steps of:
directing an incident beam of light towards the vicinity of the media edge such that a reflection of the incident beam is generated; scanning the incident beam over the media edge while monitoring the location of the incident beam in the scanning direction; monitoring the reflection of the incident beam to determine intensity and positional information therefrom; evaluating the intensity and positional information to determine of the location of the media edge.
- 2. A method according to claim 1, wherein intensity and positional information for a plurality of beam locations is accumulated and stored as data in a computer readable memory element.
- 3. A method according to claim 2, wherein the evaluating step comprises examining the data to determine the relative difference in the reflection intensity between the media surface and the media support surface and calculating a corresponding weighting factor based on the relative difference, the weighting factor subsequently applied to the intensity and positional information to determine the location of the media edge.
- 4. A system for determining the location of an edge of an imaging media, the media secured to a media support surface, the system comprising:
a carriage, adapted to traverse along a track, the carriage having mounted thereon:
i) a radiation source for directing an incident beam of light towards the vicinity of the media edge; ii) a position sensitive detector disposed to receive a reflected beam of light from the media or support surface and to generate therefrom signals responsive to the position and intensity of the reflected beam; means for indicating the location of the carriage on the track; and a controller operably connected to the detector for receiving the signals therefrom while the carriage is traversed to scan the incident beam over the media edge, the controller also being operative to analyse the signals to derive position and intensity information indicative of the location of the media edge.
- 5. A system according to claim 4, in which the carriage further supports an imaging beam source and associated optics for writing an image on the media.
- 6. A system according to claim 5, in which the radiation source is a laser.
- 7. A system according to claim 6, in which the position sensitive detector is a lateral effect position sensitive detector.
- 8. A system according to claim 7, in which the lateral effect position sensitive detector provides two signals, the sum of which is indicative of the intensity of the reflected beam and the difference between which, when normalized by the sum, is indicative of the position of the beam on the detector.
- 9. A system according to claim 4, in which the beam of light directed towards the media or support surface forms an angle of about 30° to a line drawn normal to the surface at a point where the beam is incident.
- 10. A system according to claim 4, wherein the carriage is traversed along the track using a stepper motor and the means for indicating the position of the carriage on the track comprises a counter adapted to accumulate the number of steps provided to the stepper motor.
- 11. A system according to claim 4, wherein the means for indicating the position of the carriage on the track is an encoder.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2429550 |
May 2003 |
CA |
|
RELATED APPLICATIONS
[0001] This application claims benefit of the filing date of U.S. Application 60/473127 provisionally filed on May 27, 2003 and entitled “Method and apparatus for detecting the edge of an imaging media”. This application claims benefit of the filing date of Canadian Application 2429550 filed on May 23, 2003.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60473127 |
May 2003 |
US |