The ML520/521 and ML590/591 series featured an intelligent print head with a wire-movement detector for implementing AutoGap and other functions. The intelligent head technology was technology that controlled the print force according to unevenness in the print media by detecting the movement of a wire as capacitance changes and feeding back the detected changes to the wire’s drive mechanism. This technology enabled the printers to detect the thickness of the print media or any gaps with the print media and print more consistently. This, in turn, meant better handling of more kinds of media and more stable print results.
The ML520 and ML590 had an 8-inch print width, whereas the ML521 and ML591 had a 13.6-inch print width.
| Model name | ML520 |
|---|---|
| Print process | 9 pins serial impact dot matrix |
| Interface | Centronics parallel (RS232C optional) |
| Input power supply | 120V，220/240V |
| Operating noise level | 53dBA（Quiet mode） |
| Print speed | 325 characters/s |
| Weight | 8.0kg |
| External dimensions (w x d x h) | 43 x 37.8 x 16.5 cm |
| Model name | ML590 |
|---|---|
| Print process | 24 pins serial impact dot matrix |
| Interface | Centronics parallel (RS232C optional) |
| Input power supply | 120V，220/240V |
| Operating noise level | 50dBA（Quiet mode） |
| Print speed | 360 characters/s |
| Weight | 7kg |
| External dimensions (w x d x h) | 430 X 378 X 165（mm） |
