Imaging apparatus including a movable media sensor

1. An imaging apparatus, comprising:

a printing mechanism having a media path;

a print media source for supplying a sheet of print media to said printing mechanism;

a drive unit;

a drive shaft coupled to said drive unit; and

a media sensor device having an optical sensor configured for making a media type determination mounted to said drive shaft, wherein as said drive shaft is rotated in a first direction said media sensor device is moved from a first position that is out of the media path to a second position that is in said media path for sensing said sheet of print media, and as said drive shaft is rotated in a second direction opposite to said first direction said media sensor device is moved from said second position that is in said media path for sensing said sheet of print media to said first position that is out of the media path.

2. The imaging apparatus of claim 1 , wherein said media sensor device pivots around an axis of said drive shaft.

3. The imaging apparatus of claim 1 , wherein said media sensor device comprises:

an arm having an opening for receiving said drive shaft; and

a friction device for providing a frictional coupling of said arm to said drive shaft,

wherein said optical sensor is attached to said arm.

4. The imaging apparatus of claim 3 , wherein said friction device is a friction-slip clutch configured to produce an axial load along an axis of said drive shaft to generate friction between said arm and said drive shaft.

5. The imaging apparatus of claim 3 , wherein said friction device comprises:

a bushing interposed between said arm and said drive shaft, said bushing being mounted to said drive shaft for rotation therewith; and

a spring interposed between said bushing and said arm.

6. The imaging apparatus of claim 5 , wherein said spring is a coil spring that is positioned around said drive shaft.

7. The imaging apparatus of claim 6 , wherein said bushing includes a retainer, said spring being interposed between said retainer and said arm.

8. An imaging apparatus, comprising:

a printing mechanism having a media path;

a print media source for supplying a sheet of print media to said printing mechanism;

a drive unit;

a drive shaft coupled to said drive unit; and

a media sensor device configured for making a media type determination mounted to said drive shaft, wherein as said drive shaft is rotated in a first direction said media sensor device is moved from a first position that is out of the media path to a second position that is in said media path for sensing said sheet of print media, and as said drive shaft is rotated in a second direction opposite to said first direction said media sensor device is moved from said second position that is in said media path for sensing said sheet of print media to said first position that is out of the media path,

wherein said media sensor device comprises:

an arm having an opening for receiving said drive shaft;

a friction device for providing a frictional coupling of said arm to said drive shaft; and

a sensor attached to said arm,

wherein said friction device comprises:

a bushing interposed between said arm and said drive shaft, said bushing being mounted to said drive shaft for rotation therewith; and

a spring interposed between said bushing and said arm,

wherein said bushing has a non-circular opening for receiving said drive shaft, and drive shaft has a profile in cross-section corresponding to said non-circular opening.

9. The imaging apparatus of claim 8 , wherein said non-circular opening is a D-shaped opening.

10. An imaging apparatus, comprising:

a printing mechanism having a media path;

a print media source for supplying a sheet of print media to said printing mechanism;

a drive unit;

a drive shaft coupled to said drive unit; and

a media sensor device configured for making a media type determination mounted to said drive shaft, wherein as said drive shaft is rotated in a first direction said media sensor device is moved from a first position that is out of the media path to a second position that is in said media path for sensing said sheet of print media, and as said drive shaft is rotated in a second direction opposite to said first direction said media sensor device is moved from said second position that is in said media path for sensing said sheet of print media to said first position that is out of the media path,

wherein said media sensor device comprises:

an arm having an opening for receiving said drive shaft;

a friction device for providing a frictional coupling of said arm to said drive shaft; and

a sensor attached to said arm,

wherein said friction device comprises:

a bushing interposed between said arm and said drive shaft, said bushing being mounted to said drive shaft for rotation therewith; and

a spring interposed between said bushing and said arm,

wherein said spring is a coil spring that is positioned around said drive shaft;

wherein said bushing includes a retainer, said spring being interposed between said retainer and said arm; and

wherein said retainer is a shoulder that extends radially from a body of said bushing.

11. The imaging apparatus of claim 10 , wherein said shoulder is a snap ring that engages said body of said bushing.

12. An imaging apparatus, comprising:

a printing mechanism having a media path;

a print media source for supplying a sheet of print media to said printing mechanism;

a drive unit;

a drive shaft coupled to said drive unit; and

a media sensor device configured for making a media type determination mounted to said drive shaft, wherein as said drive shaft is rotated in a first direction said media sensor device is moved from a first position that is out of the media path to a second position that is in said media path for sensing said sheet of print media, and as said drive shaft is rotated in a second direction opposite to said first direction said media sensor device is moved from said second position that is in said media path for sensing said sheet of print media to said first position that is out of the media path,

said media sensor device comprising:

an arm having a proximal end and a distal end, said arm being pivotably mounted to said drive shaft;

a sheet picking roller mounted to said arm near said distal end of said arm, said sheet picking roller being driven by said drive shaft; and

a media sensor mounted to said arm.

13. An imaging apparatus, comprising:

a printing mechanism having a media path;

a print media source for supplying a sheet of print media to said printing mechanism;

a drive system; and

a media sensor device having an optical sensor configured for making a media type determination mounted to said drive system, said drive system effecting a movement of said media sensor device toward a surface of said sheet of print media from a first position that is out of the media path to a second position that is in said media path for sensing said sheet of print media, and said drive system effecting a movement of said media sensor device away from said surface of said sheet of print media from said second position that is in said media path for sensing said sheet of print media to said first position that is out of the media path.

14. The imaging apparatus of claim 13 , wherein said drive system comprises:

a drive unit; and

a drive shaft coupled to said drive unit.

15. The imaging apparatus of claim 14 , wherein said media sensor device is mounted to said drive shaft.

16. The imaging apparatus of claim 15 , wherein as said drive shaft is rotated in a first direction said media sensor device is moved from said first position that is out of the media path to said second position that is in said media path for sensing said sheet of print media, and as said drive shaft is rotated in a second direction opposite to said first direction said media sensor device is moved from said second position that is in said media path for sensing said sheet of print media to said first position that is out of the media path.