Casio UP-250 Technical Manual page 6

Chapter 2 Mechanism Configuration and Operating Principles ........................... 26
Printer Mechanism Operating Principles ................................................................... 26
Print mechanism unit ........................................................................................................ 27
Print head unit movement ................................................................................................. 28
Wire movement when a single dot is printed .................................................................... 28
Printing a character (9x9 font) ......................................................................................... 29
Paper Feed Mechanism Unit ............................................................................................ 30
Paper loading (semi-automatic loading) ........................................................................... 31
Paper feeding ................................................................................................................... 31
Ribbon Feed Mechanism Unit .......................................................................................... 32
Ribbon feeding ................................................................................................................. 33
Detection Mechanism Unit ................................................................................................ 34
Home position detection mechanism ................................................................................ 34
Paper detection mechanism ............................................................................................. 35
Paper roll near-end detection mechanism (optional) ........................................................ 35
Auto-cutter mechanism ..................................................................................................... 35
Ribbon Switch Mechanism Unit ................................................................................. 36
Switching from Black to Red ............................................................................................. 36
Releasing from Red to Black ............................................................................................ 36
Electrical Circuitry Operating Principles ................................................................... 37
Hardware Configuration .................................................................................................... 37
Principles of Operation ............................................................................................... 41
Power Supply Circuitry ..................................................................................................... 41
Control Circuitry ................................................................................................................ 42
CPU .................................................................................................................................. 43
Various detector circuits .................................................................................................... 46
Host interface circuit ......................................................................................................... 47
Drawer kick-out drive circuit ............................................................................................. 47
DIP switch read circuit ...................................................................................................... 48
Printer Mechanism Driver Circuits ............................................................................. 50
Print head driver circuit ..................................................................................................... 50
Paper feed motor driver circuit ......................................................................................... 51
Carriage motor driver circuit ............................................................................................. 51
Auto-cutter driver circuit .................................................................................................... 52
Chapter 3 Handling and Maintenance ..................................................................... 53
Handling Precautions .................................................................................................. 53
Storage Precautions ......................................................................................................... 53
Use Precautions ............................................................................................................... 53
Paper Handling Precautions ............................................................................................. 53
Ribbon Cassette Handling Precautions ............................................................................ 54
Replacing the Paper Roll ............................................................................................. 54
Replacing the Ribbon Cassette .................................................................................. 57
Removing Jammed Paper ........................................................................................... 60
Using the Power Switch Cover ................................................................................... 64
Inspection and Maintenance ....................................................................................... 65
Cleaning ........................................................................................................................ 66