Patent Application
20230066010
This application relates generally to printing. The application relates more particularly to enhanced speed for thermal printers.
Thermal printing, or direct thermal printing, is a process for printing digitally encoded images. Thermal printers typically operate to produce printed images using paper with a thermochromic coating, commonly known as thermal paper. The paper contacts a print head comprised of tiny electrically heated elements. The coating turns black in the areas where it is heated, producing an image. Most thermal printers are monochromatic, rendering images in black and white.
Various embodiments will become better understood with regard to the following description, appended claims and accompanying drawings wherein:
The systems and methods disclosed herein are described in detail by way of examples and with reference to the figures. It will be appreciated that modifications to disclosed and described examples, arrangements, configurations, components, elements, apparatuses, devices methods, systems, etc. can suitably be made and may be desired for a specific application. In this disclosure, any identification of specific techniques, arrangements, etc. are either related to a specific example presented or are merely a general description of such a technique, arrangement, etc. Identifications of specific details or examples are not intended to be, and should not be, construed as mandatory or limiting unless specifically designated as such.
A thermal printer requires intimate contact with the paper or print media to which an image is being transferred. Not only is intimate contact needed, but also contact under a relatively high load, such as in a range of 13-19 pounds (approximately 58 newtons - 85 newtons). In a typical example printer, force may be around 16 pounds (approximately 71 newtons) of force. A typical system has a thermal print-head mounted on a spring loaded platen which applies a force against a driven roller which pulls the media across the face of the print head. A solenoid is used to pull the print head assembly back when it is not time to print.
In example embodiments herein, printer operation is improved by employing a cam mechanism to move the impact mechanism quickly at first with little force and progress to move more slowly with greater force as contact is being made.
Actual force on the thermal printhead 220 is constrained by use of biasing spring 244 affixed to the thermal printhead 220. When contact is made with the thermal printhead 220, biasing spring 244 is compressed and force is limited to a value associated with its spring constant k with the equation:
wherein the constant force F is specified by the spring constant and x is a spring displacement distance.
The above-described system is referred to as direct thermal printing insofar as the media itself is thermally sensitive. In indirect thermal printing, thermal paper or ribbon is heated by a printhead and an image is transferred onto media, such as paper. Illustrated in phantom in
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the spirit and scope of the inventions.
This application claims priority to U.S. provisional application Serial No. 63/239,994 filed Sep. 2, 2021.
| Number | Date | Country | |
|---|---|---|---|
| 63239994 | Sep 2021 | US |
