| United States Patent | 5,837,962 |
| Overbeck | Nov. 17, 1998 |
Abstract
By adding an acousto-optic deflector to an existing design of laser marker the laser marker's throughput is increased by a large factor, typically a factor of 5. Galvanometer driven mirrors, which in existing laser markers are used to trace out the strokes in characters are, in this invention, used only to scan smoothly along lines of characters. The acousto-optic deflector, being much faster than the galvanometers, is used to trace out the individual strokes in the characters. Marking rates of 1000 characters per second are achieved in the case of characters for which capital letters are 2 millimeters high and a 2 millimeter long stroke contains 13 laser-produced craters. This performance is achieved over fields as large as 300 millimeters square. The quality of marked characters is improved because the deleterious effects of mirror inertia on character quality, commonly seen when a laser marker is pushed for speed, are eliminated.
| Inventors: | Overbeck; James W. (112 Martins La., Hingham, MA 02043). |
| Appl. No.: | 680,484 |
| Filed: | Jul. 15, 1996 |
| Intl. Cl. : | B23K 26/08 |
| Current U.S. Cl.: | 219/121.68; 219/121.6; 219/121.75; 219/121.79; 347/259 |
| Field of Search: | 219/121.68, 121.69, 121.78, 121.79, 121.8, 121.81, 121.82, 121.73, 121.74, 121.75, 121.6; 359/196, 225, 285, 305; 347/224, 225, 259, 260; 346/107.3, 107.4, 107.5 |
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