Star Micronics TSP400 technical manual Printer Mechanism, Thermal Head, Paper-Feed Mechanism

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THEORY OF OPERATION

3.Printer Mechanism

3-1. Thermal Head

The TSP400 printers employ thermal line printing. The thermal head consists of a horizontal line of 640 heat elements. These elements print one line of dots at a time as the paper passes over the head. The head is fixed in position; only the paper moves.

The printer prints a dot by heating the corresponding heat element. The heated element causes a chemical reaction in the coloring layer of the thermal paper, resulting in the formation of a visible dot.

Thermal head

Heat element

Coloring layer

Thermal paper

Printed point

Platen

Fig. 2-13 Principle of Thermal Printing

3-2. Paper-Feed Mechanism

The paper-feed mechanism is comprised of the paper-feed motor, gear train, platen, and thermal head. The paper-feed motor drives the gear train, which in turn rotates the platen. The platen carries the thermal paper past the thermal head.

The paper-feed motor is a PM (permanent magnet) type, 4-phase 48-pole step motor. A single step feeds the paper approximately 0.125mm.

Thermal head

Thermal paper

Platen

Gear train

Paper-feed motor

Fig. 2-14 Paper-Feed Mechanism

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Contents TSP400 Series Page Introduction Page Chapter Specifications and Operation Specifications and Operation OCR-B General SpecificationsInternal Configuration TSP412D External Appearance and Internal ConfigurationDIP-Switch Settings Status of printer power Baud Print-Density Adjustment Sensor Adjustment Specifications and Operation Setting Memory Switches from the Control Panel HEX Dump Test PrintPage/Line Mode Switch Exposing the Peripheral Unit Connector Changing the Interface Board Specifications and Operation Chapter Theory of Operation Theory of Operation 24V Block DiagramControl Panel Interface Main and Interface PCBs2. RS422A interface Parallel Interface PCB Main PCB Editing Editing and PrintingTiming Chart Feed-Motor Drive Circuit Motor Control by Phase 1-2 ExcitationPower-On Reset Circuit 11 Equivalence Circuit for Voltage Detecting IC +5V Line Voltage Detector CircuitPrinter Mechanism Thermal HeadPaper-Feed Mechanism 15 Paper-Out Detector Detectors19 Head-Up Detector Page Chapter Parts Replacement and Related Adjustments Parts Replacement TSP412D Upper Casing UnitControl-Panel Board Printer Mechanism Main PCB, Interface PCB Fuse Power UnitPrinthead unit Feed Motor AssemblyLabel sensor DetectorsParts Replacement Chapter Maintenance and Lubrication Maintenance and Lubrication Maintenance CleaningChecks Lubricants LubricationApplication Method Lubrication PointsLubrication Points Maintenance and Lubrication Chapter Parts List Disassembly Drawing Printer AssemblyTSP442D Printer Assembly Parts ListScrew TAT Printer Mechanism Assembly Oiless Bushing F4X7X3 Printer MechanismRS-232C Interface Type Connector Wiring DiagramRS422A I/F Board Control Board Parallel Interface Type Main Logic Board Circuit DiagramSide a Side D Side C Main Logic Board Chip Resistor 20 K-OHM 1/10W CN8 RS232C Interface RS232C Interface Board RS422A Interface RS422A Interface Board CentronicsInterface Centronics Interface Board Control Panel Board Control Panel Board Label Sensor Board Paper-Out Detector BoardPaper-Out Detector Transmissive SensorPage Distributed by