Monarch 9820TM Supply Sensing Systems, Supply DETECTION/TRACKING System, Version 5.2 or greater

CHAPTER 8 SUPPLY SENSING SYSTEMS

Several supply sensing systems have been used for the 9800 series printers. This chapter contains:

∙Supply detection and tracking for each printer.

∙A description of the supply deflector, Bi-cell emitter, lower supply guide, and Bi-cell sensor.

∙Sensor tests and adjustments for each sensing system.

∙Information about the version 5.2 sensing system.

SUPPLY DETECTION/TRACKING SYSTEM

An electro-optical system, consisting of a single infrared emitter and a bi-cell sensor, allows the printer to support die-cut, butt-cut (black mark only), with aperture, and non-indexed supplies. The supply detection and tracking system detects the document edge position and out-of-stock condition. The infrared emitter is located above the web path and is positioned to allow the bi-cell sensor detector to serve as a receiver for recognizing die-cut supplies.

Version 5.2 or greater:

The software uses an adaptive threshold algorithm that has successfully been used in the M9446 printer. This method provides the benefit of accurately processing apertures, die cut gaps, and black marks even though the electronic signal response may vary greatly between supply types. It consists of measuring the difference between the minimum and maximum A/D (Analog to Digital converter) values captured from the sensor.

The amplitude of this signal range represents the sensor response to the feature. The minimum value captured plus half the height of the signal range constitutes the threshold level for both the Top of Form (TOF) and Bottom of Form (BOF). This means that on the leading edge of the feature when the threshold value is crossed the BOF is marked. Likewise when the feature is departing the sensor and the trailing edge threshold is crossed the TOF is marked.

TOF/BOF Threshold = Low value + ((High Value - Low Value) / 2)

The paragraph above describes how the algorithm is developed on one feature. For V5.2 the threshold will

be an average threshold value calculated from the previous two features.

TOF/BOF Average = (BOF/TOF Threshold1 + BOF/TOF Threshold2) / 2

SUPPLY DEFLECTOR/BI- CELL EMITTER (IR LED)

The supply deflector is attached to the bottom of the print module and pivots up and down to load labels and ribbon. The IR Emitter is mounted in the center of the deflector, which positions it in the middle of the paper path and above the supply sensor located in the supply guide.

Version 5.2 or greater:

The sensing system consists of three sensing systems: an edge justified transmissive sensor, a center justified reflective sensor, and a center justified transmissive sensor which contains an LED positioned directly over the phototransistor of the reflective sensor.

The edge justified transmissive sensor provides an index signal when using die cut labels and edge justified aperture tags. It is mounted on the inside supply guide and moves with the guide depending on the supply width. This sensor is connected with an integral harness to the reflective sensor junction board.

The center justified overhead LED is mounted in the upper supply guide (flapper) and the phototransistor of the reflective sensor (located below the web) and provides an index signal when using center justified aperture tags. The overheard LED is connected with a harness to the reflective sensor junction board. A wire harness connected between the main PCB and the reflective sensor junction board provides the path for the power, ground, LED power, and sensor output signals.

NOTE: The new supply guide mechanisms are not backward compatible.

July 1998 TC9830SM Rev. B 7/98 Confidential 37