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US 6,217,168 B1Granted
Transparency detection in a tray
AssigneeHewlett-Packard Company
InventorSteven B Elgee
Life of this patent
Estimating the term…
Abstract
A printing system that includes a transparency film detector having a light source for illuminating a sheet of input media and a detector for detecting whether a portion of the light provided by the light source propagated by internal reflection within the volume of the illuminated input media sheet is detected.
Claims13
A printing system comprising:
- marking apparatus for applying marks to a print medium;
- a media tray for storing print media including a top print media sheet having a top surface;
- a light source for illuminating the top print media sheet with an incident beam at an incidence angle selected such that if the top print media sheet is a transparency film a portion of said incident beam would enter the transparency film and propagate in the transparency film by internal reflection;
- a detector for detecting internal reflection of a portion of said beam within the top print media sheet.
1 more element
A method of operating a printing device having an input media tray for supporting print media including a top print medium sheet and marking apparatus for making marks on a print medium, the method comprising the steps of:
- illuminating the top print medium sheet with an incident beam at an incidence angle selected such that if the top print medium sheet is a transparency film a portion of said incident beam would enter the transparency film and propagate in the transparency film by internal reflection;
- detecting whether a portion of the incident beam is propagated by internal reflection within the top print medium sheet;
- and
- printing on the top print medium sheet using printing attributes appropriate for a transparency film if a portion of the incident beam propagated by internal reflection within the top print medium sheet is detected.
1 more element
Dependencies are inferred from the claim text.