Operation Of Sensors And Leds; Paper Entrance / Black Mark Sensor - Hengstler TS-56 Operating Manual

TwinSide TS™ Thermal Printer Family

2.5. Operation of Sensors and LEDs

2.5.1. Paper Entrance / Black Mark Sensor

There is a sensor in the paper entrance area that serves several functions. First, it
detects paper during paper loading and signals the printer to begin the paper auto-
loading function. Similarly, when the printer is out of paper, this sensor detects the
fact and signals the printer accordingly.
The same sensor is also used to detect Black Marks, when the printer is so equipped.
Black Marks are blackened areas preprinted on the paper during the converting
process. They are generally used, in conjunction with appropriate printer commands,
to advance the paper to a specific position after each print job. One common reason
for this is to so that preprinted information is properly located with respect to
information printed by the printer itself, for example, printing inside a preprinted box.
Black marks can be located on either the front or the back of the paper, depending
upon the location of the sensor.
The TwinSide TS™ series of printers is designed to allow for several Paper
Entrance/Black Mark sensor locations during manufacturing. (The location of this
sensor cannot be changed once the printer is built.) Also, two different sensor types
can be used. The most common is the reflex or reflective sensor, where the light
source and detector are located on a single chip. Basically, the light strikes the white
paper surface and reflects back into the sensor. If enough light reflects to activate the
sensor, the printer concludes that paper is present.
reflected, the printer assumes that this area is black, meaning the printer is on a black
mark or the printer is out of paper. There are six (6) different possible positions for
this sensor in the TS-56. Half of these positions sense the coated side of the paper,
while the other half sense the back of the paper. The positions of these sensors are
detailed in the "Black Mark Sensor" portion of this document.
Part No. D 691 023A
Figure 5
Mod. No. 4 120912 LEV
HENGSTLER
If there is not enough light
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