Kodak i1800 Series Image Processing Manual page 27

Transfer Patch Code
The image header reflects when a Transfer patch code is detected on a
document. A document containing a Transfer patch is considered to be
a Level 0 document. The IA level for the next document following the
Transfer patch is assigned to the level (Level 2 or Level 3) that has
been previously set. The scanner cannot print on documents containing
Transfer patches. In the image header for the document containing the
Transfer patch, the document level is returned as 0 and the patch type
returned as T to reflect the Transfer patch definition. For the document
following the Transfer patch document the image header will contain a
document level of 2 or 3 depending on the Transfer patch type
definition and will reflect no patch detected.
Toggle Patch
The Toggle patch is a Type 4 patch that is used to trigger the scanner to
switch from the current image stream (black and white) to the
alternative image stream (color/grayscale). This logic is performed
inside the scanner. Images of the toggle patch sheet will not be
returned to the host unless you also enable patch reading and select
the Type 4 patch. Common uses for this patch would be a document
set, which is primarily black and white but has some color content.
Placing a Toggle Patch sheet before and after the color document(s)
would allow changing from black and white to color and back on-the-fly
during scanning with no additional operator action.
NOTE: Toggle patch may also be used to trigger the scanner to switch
from black and white to grayscale and vice versa.
Additional Patch Codes
Additional patch codes enable the host to implement any type of
workflow-dependent processing to be based on the insertion of these
additional patches into the document stack. Additional patches are
patch types 1, 4 and 6.
When an additional patch is detected, this document is considered a
Level 0 document and will not cause the IA to change. The image
header indicates that this is an additional patch document by returning
a patch type, which matches the patch detected. The scanner will not
print on documents containing these additional patches.
A-61580 November 2007
2-23