The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 14, 1997
Filed:
Sep. 30, 1996
Darrel R Rathbun, Ontario, NY (US);
Xerox Corporation, Stamford, CT (US);
Abstract
A filming attenuation correcting toner concentration sensor assembly and method of controlling in a container, a concentration of a mixture that includes a light absorbing substance and a clear liquid carrier in solution, while correcting the effects of container filming. The method includes the steps of splitting light from a single light source having a controllable intensity, into a first light beam and a separate second light beam; focusing the first light beam through a first quantity of the mixture contained in a first light transmitting container made of a first material and having a first thickness, as well as focusing the second light beam through a second quantity of the mixture contained in a second light transmitting container made of the first material and having a second thickness greater than the first thickness of the first light transmitting container; generating a first proportional output signal by sensing with a first photodiode, a first attenuated light transmitted from the first light beam through the first light transmitting container and through the first quantity of the mixture; generating a second proportional output signal by sensing with a second photodiode, a second attenuated light transmitted from the second light beam through the second light transmitting container and through the second quantity of the mixture; maintaining the second proportional output signal at a constant level by adjusting the controllable intensity of the single light source; and adjusting the concentration of the light absorbing substance in the mixture such that a filming-effect independent ratio that is equal to the first proportional output signal divided by the second proportional output signal, is also maintained as a constant, thereby achieving a toner concentration of the mixed developer material that is maintained at a desired level, without the undesirable effects of filming of optical surfaces.