Browse Prior Art Database

Original Publication Date: 1986-Oct-31
Included in the Prior Art Database: 2004-Apr-04

Publishing Venue

Xerox Disclosure Journal


A desirable feature for a photocopier is deletion of specified areas of an original document and/or copying of specified areas of the document in a color different from the origmal One enabling method is to first use a yellow pen to mark the areas to be highlighted Yellow is an optimum highIi,hting color since many machine photoreceptors are blind to the color and the color 1s rarely used as an image color The original document is then scanned and imaged onto a photosensor array A double filter is positioned over the detector array Half would be dear (ur non-existent), the other half would be blue or cyan A two level detector A h L) circuit would be employed The yellow would produce a high output with the clear filter and a very low output with the blue filter The AND circuit would detect this unique output pair A cyan instead of the blue filter might be necessary to provide suficient signal from white paper because photodiodes are usually rather insensitive in the blue spectral region