The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 20, 1986
Filed:
May. 28, 1985
Michael J Sullivan, Portsmouth, RI (US);
Astro-Med, Inc., West Warwick, RI (US);
Abstract
An electrical circuit for controlling the energization of thermal print head elements on a thermal print head. The circuit is responsive to the overall temperature of a thermal print head for varying the amounts of energy supplied the print head elements thereof so that markings of substantially uniform darkness can be produced on thermally sensitive sheets regardless of the overall head temperature. The circuit is operative in response to a start signal for producing a predetermined number of sequential pulses of substantially uniform duration during a printing cycle to sequentially energize different groups of print head elements at different times during the cycle. The voltage level of the pulses in the cycles is maintained substantially constant, whereas the duration of the pulses in different cycles is varied to vary the amounts of energy supplied to the print head elements.