Patent ID: 7690778

Claim:
A printhead auto-alignment detection system, comprising: a) a UV LED configured and positioned to transmit light in ultraviolet wavelengths onto a printed printhead alignment pattern formed using an aqueous ink having an added UV fluorescing material that absorbs light from said UV LED in the wavelengths in a range between 250 nm to about 400 nm and emits light in the wavelengths in a range between 500 nm to 700 nm, wherein said UV fluorescing material is a dye or pigment; b) a sensor configured and positioned to detect light in visible wavelengths emitted by said fluorescing material and to block light with wavelength between 300 nm to 500 nm; and c) a controller communicatively coupled to said UV LED and said sensor, said controller being configured to execute program instructions for controlling the output of said UV LED and for reading a signal output of said sensor during a printhead alignment operation.