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:
Oct. 05, 2004
Filed:
Jul. 07, 2003
Chi-Lun Chen, Hsin-Chu Hsien, TW;
Sheng-Lung Tsai, Ping-Tung Hsien, TW;
BenQ Corporation, Tao-Yuan Hsien, TW;
Abstract
A printing apparatus includes a printhead and an ink volume detecting circuit. The printhead contains a plurality of first heating elements for heating ink supplied to the printhead to generate bubbles in the ink and eject the ink through corresponding nozzles. The printhead also contains a second heating element for heating the ink supplied to the printhead, a resistance value of the second heating element being less than the resistance value of each first heating element, and the low resistance value of the second heating element causing the second heating element to burn out and create an open circuit if the volume of the ink is less than a predetermined level. The ink volume detecting circuit is connected to the second heating element for determining if the volume of the ink supplied to the printhead is less than the predetermined level based on a condition of the second heating element.