Gradation record printer
US5214446A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 28, 1991 |
| Grant date | May 25, 1993 |
| Priority date | — |
| Expiry date | Jan 28, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4078
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A gradation record printer in which an amount of energy applied to a thermal head is controlled in response to a gradation level of an input image signal to print an image on a printing medium with gradations. The printer comprises a gradation density detecting unit for storing data of standard density patterns with respect to address values corresponding to gradation levels and for outputting a coincidence signal when data supplied from an outside of the gradation density detecting unit substantially coincides with the data of standard density patterns. A gradation test print circuit is used to apply data of different amounts of printing energy to the thermal head sequentially to make a gradation test print on the printing medium. A density detecting sensor detects densities of the gradation test print and applies a detection output from the density detecting sensor to the gradation density detecting unit. A memory element stores the data of different amounts of energy with respect to address values corresponding to the gradation levels in response to the coincidence signal from the gradation density detecting unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.