Compact scanner and scanning method

• US 20030234963A1
• Filed: 06/19/2002
• Published: 12/25/2003
• Est. Priority Date: 06/19/2002
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Haas, William Robert, Tecu, Kirk Steven, Boll, Dave
• Granted Patent: US 7,019,872 B2
• Time in Patent Office: Days
• US Class Current: 358/474
• CPC Class Codes: H04N 1/1017 the main-scanning components remaining positionally invariant with respect to one another in the sub-scanning direction
• CPC Class Codes: H04N 1/193 using electrically scanned linear arrays , e.g. linear CCD arrays
• CPC Class Codes: H04N 2201/044 Moving a scanning element into cooperation with a calibration element, e.g. a grey-wedge mounted on the document support, or vice versa

Abstract

A scanner comprises a transparent platen mounted on a housing, and an object-imaging device within the housing mounted for longitudinal movement relative to the platen and an object supported thereby. The object-imaging device is rotatable about a transverse axis and comprises an aperture for receiving light reflected from the object. The object-imaging device has a travel distance between a home end position and a back end position, the travel distance comprising a central portion and at least one end portion. The scanner further comprises a mechanism operatively associated with the object-imaging device for rotating the device about the transverse axis thereof in response to movement of the device within the at least one end portion of the travel distance, the device being rotated in a direction so that the light-receiving aperture is rotated away from the central portion of the travel distance.

There is also provided a method of scanning an object placed on the platen of a scanner, the scanner comprising an object-imaging device translatable relative to the platen between a home position and a back end position remote from the home position, the scanner further comprising a calibration means at the home position. The method comprises scanning the object in a scanning direction with the object-imaging device while translating the object-imaging device from the home position to the back end position, translating the object-imaging device in a return direction toward the home position, rotating the object-imaging device within a home end portion of the travel of the object-imaging device, and calibrating the object-imaging device within the home end portion of the travel thereof.

Claims

1. A scanner comprising:

a transparent platen mounted on a housing;

an object-imaging device within the housing mounted for longitudinal movement relative to the platen and an object supported thereby, the object-imaging device being rotatable about a transverse axis and comprising an aperture for receiving light reflected from said object, said device having a travel distance between a home end position and a back end position, the travel distance comprising a central portion and at least one end portion; and

a mechanism operatively associated with the object-imaging device for rotating the device about the transverse axis in response to movement of the device within said at least one end portion of the travel distance, the device being rotated in a direction so that the light-receiving aperture is rotated away from the central portion of the travel distance.

2. The scanner of claim 1 in which:

the object-imaging device comprises a charge coupled-device.

3. The scanner of claim 1 in which:

within the central portion of the travel distance of the object-imaging device, the aperture therein is oriented to receive light from the object along a path perpendicular to an object-supporting surface of the platen.

4. The scanner of claim 1 in which:

within the at least one end portion of the travel distance of the object-imaging device, the aperture therein is oriented to receive light from an end portion of the object.

5. The scanner of claim 4 further comprising:

a white balance surface for correcting for variations in the intensity of the reflected light within the at least one end portion of the travel distance of the object-imaging device during rotation thereof.

6. The scanner of claim 1 in which:

within the at least one end portion of the travel distance of the object-imaging device, the aperture therein is oriented to receive reflected light from a calibration surface.

7. The scanner of claim 1 in which:

the mechanism for rotating the object-imaging device comprises a projection on the housing adapted to intercept a surface on the device to cause rotation thereof about the transverse axis.

8. The scanner of claim 1 in which:

said at least one end portion of the travel distance of the object-imaging device comprises a back end portion of said travel distance.

9. The scanner of claim 8 in which:

said travel distance of the object-imaging device further comprises a home end portion, said central portion of the travel distance lying between the home end and back end portions of the travel distance; and

in which said scanner further comprises;

a mechanism operatively associated with the object-imaging device for rotating the device about the transverse axis in response to movement of the device within the home end portion of said travel distance, the device being rotated within said home end portion of the travel distance in a direction so that the light-receiving aperture is rotated away from said central portion of the travel distance.

10. A method of scanning an object placed on the platen of a scanner, the scanner comprising an object-imaging device translatable relative to the platen between a home position and a back end position remote from the home position, the scanner further comprising a calibration means at the home position, the method comprising the steps of:

scanning the object in a scanning direction with the object-imaging device while translating the object-imaging device from the home position to the back end position;

translating the object-imaging device in a return direction toward the home position;

rotating the object-imaging device within a home end portion of the travel of the object-imaging device; and

calibrating the object-imaging device within the home end portion of the travel thereof.

11. The method of claim 10 in which the object scanning step further comprises the step of:

rotating the object-imaging device within a back end portion of the travel of the object-imaging device adjacent the back end position in a direction so as to continue scanning the object in the scanning direction.

12. The method of claim 11 further comprising the step of:

correcting for variations in the reflected light from the object during rotation of the object-imaging device within the back end portion of said travel.

13. A method of scanning an object placed on the platen of a scanner, the scanner comprising an object-imaging device translatable relative to the platen between a home position and a back end position remote from the home position, the method comprising the steps of:

scanning the object in a scanning direction with the object-imaging device while translating the object-imaging device from the home position to the back end position; and

rotating the object-imaging device within a back end portion of the travel of the object-imaging device adjacent the back end position in a direction so as to continue the scanning of the object in the scanning direction.

14. The method of claim 13 comprising the step of:

returning the object-imaging device to the home position.

15. The method of claim 14 comprising the step of:

calibrating the object-imaging device at the home position.

16. The method of claim 15 in which:

the step of calibrating the object-imaging device is performed by scanning a surface having a known reflectance.

17. The method of claim 16 in which:

the calibrating step is carried out during rotation of the object-imaging device within a home end portion of the travel of the object-imaging device.

18. The method of claim 17 further comprising the step of:

rotating the object-imaging device during the calibrating step in a direction opposite the direction of rotation of the first mentioned rotating step.

19. The method of claim 13 in which:

the step of rotating the object-imaging device within a back end portion of the travel of the object-imaging device begins after completion of the translating step.

20. The method of claim 13 further comprising the step of:

correcting for variations in the reflected light from the object during rotation of the object-imaging device within the back end portion of said travel.