Thermal printer label gap sensor and method for controlling same
US5438349A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 1992 |
| Grant date | Aug 1, 1995 |
| Priority date | — |
| Expiry date | May 22, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J11/46
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
An apparatus and method for sensing gaps between labels adhered to a backing material in longitudinally spaced-apart positions as the backing material travels along the print path of a thermal printer. An array of light-emitting diodes oriented transverse to the print path illuminates the backing material. A fiber optic detects the light transmitted through the backing material and passes the light to a photodiode. The photodiode produces an analog electrical signal indicative of the amount of light transmitted, which varies depending on whether the light has passed through only the backing material or through both the backing material and the print media it carries. The analog signal is converted to a digital signal which is processed by a microprocessor to monitor and control the advancement of the print media and backing material through the printer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.