Method for producing a halftone plate
US4447833A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 31, 1981 |
| Grant date | May 8, 1984 |
| Priority date | — |
| Expiry date | Dec 31, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/40081
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for producing a halftone plate from an original picture having a continuous tone. A record film is exposed at least one exposure light beam of a smaller size than a halftone dot area by independently controlling it to turn on or off according to a picture signal. The luminous energy of the exposure light beam is controlled depending on a reference value corresponding to the picture signal and a position signal value varied depending on an exposing position in the halftone dot area to be exposed by the exposure light beam. The control of the luminous energy is performed by the sum, the difference, the product or the quotient of the two signal values. A plurality of reference values or position signal values may be used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.