Method for measuring ink density
US4712918A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 1984 |
| Grant date | Dec 15, 1987 |
| Priority date | — |
| Expiry date | Nov 14, 2004 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41F33/0063
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
In a method for measuring ink density of printed sheets by means of photodiodes which scan light reflection from measuring marks provided on printed sheets, the start of a dynamic measuring process during the running of the printing machine is released by the control of impulse flanks, and the reflected light is scanned by sensors having a short response time. A medium reflection value of the surface of the measuring mark is determined. The control of impulse flanks takes place by a leading edge of the mark printed on the sheet, and the signal, released by that control, switches on the photodiodes and the light source. A changed voltage occurring at the output of each photodiode is amplified, and its peak value is stored; and the photodiodes and the light source are switched off thereafter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.