Optical registration system for label printer cutter attachment
AssigneeFargo Electronics, Inc.
InventorsMichael R. Tolrud, Matthew K. Dunham, Gary M. Klinefelter
Life of this patent
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Abstract
A detector assembly for detecting registration marks on a printed sheet when different color printing on different colored sheets is present has a pair of light sources and a light sensor. The light sources are of different colors selected to be complimentary such that one light source or the other will be capable of detecting a substantial range of contrasting registration marks placed on sheets that can be of various colors. Controls are used for selecting the light source that provides an output sensed by a light sensor when passing over the registration marks.
Claims15
An apparatus for registering a sheet position and performing an operation on a sheet referenced to a registration mark on the sheet, comprising:
- a positioning mechanism for causing relative movement between the sheet and a tool performing the operation, based upon control signals;
- an optical detector mounted on the apparatus providing a sensor output in response to detection of a registration mark on the sheet, the optical detector including first and second light sources directed toward the sheet, each of the light sources providing light of a different color from the other, and a light sensor to sense light reflected from the sheet;
- and
- control circuitry connected to the light sources including a control to first select a first of the light sources for illuminating a registration mark on a sheet and subsequently selecting the second light source for illuminating the registration mark in response to absence of a signal from the light sensor when using the first light source.
An optical detector assembly for detecting contrasting registration marks on a sheet through optical sensing of reflecting light comprising a support for operably holding the optical detector in position adjacent a sheet, and causing relative movement between the sheet and the sensor;
- the optical detector including a pair of light sources of different colors directed toward the sheet, and a light sensor to sense light reflected from the sheet;
- and
- a control circuit for initially energizing a first of the light sources and moving it across a known position to sense the registration mark on the sheet, and for selecting a second light source when the signal from the light sensor indicates lack of a registration mark at the known location using the first light source.
A method of detecting registration marks on a sheet using a sensor that is movable along at least one axis relative to the sheet, comprising the steps of:
- providing a registration mark on the sheet having a contrasting reflectivity relative to the surface of the sheet;
- providing a pair of light sources of different colors to direct light onto the sheet and a light sensor to sense reflected light from the sheet;
- energizing one of the light sources and relatively moving the one light source and light sensor across the registration mark and determining whether the presence of a registration mark is sensed by the light sensor;
- and
- in response to a determination that the registration mark is not sensed selecting the second light source and relatively moving the second light source and light sensor across the registration mark to sense the position of the registration mark.
Dependencies are inferred from the claim text.