Patent ID: 7018121

Claim:
A method of detecting the presence and type of media in the media path of an image forming apparatus, comprising: directing optical energy from an optical source to an optical detector; directing said optical energy through at least two distinct locations along said media path; reflecting said optical energy off at least two reflective surfaces; detecting and quantifying optical energy from said optical source at said optical detector, the steps of directing optical energy from said optical source to said optical detector and detecting and quantifying optical energy from said optical source at said optical detector respectively comprising directing and receiving optical energy at substantially equal, but opposite angles with respect to a direction normal to said media path; and in response to detecting and quantifying said optical energy at said detector, determining whether no media, opaque media, or transparent media is present in said media path by detecting a level of optical energy in the case of transparent media that is between that in cases of opaque media and no media present.