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:
Feb. 13, 2001
Filed:
Apr. 07, 1999
Shu-Cheng Hsieh, Hsinchu Hsien, TW;
I-Chung Hou, Hsinchu, TW;
Cheng-Wei Hsu, Yungkang, TW;
Chi-Chien Lin, Hsinchu Hsien, TW;
Industrial Technology Research Institute, Hsinchu, TW;
Abstract
The present invention provides a pressure control apparatus for an ink-jet pen. The apparatus will adjust the back pressure of ink in the reservoir of the ink-jet pen in a suitable range when the ink is used gradually. The apparatus includes a pressure adjusting element and a hole furnished on the bottom wall of a reservoir. Under normal condition, the pressure adjusting element contacts tightly to the hole and prevents air from ingression. When the back pressure increases gradually to an extent, the ambient air will overcome the pressure of a spring which provides force to the pressure adjusting element, thus move the pressure adjusting element to leave a clearance to the hole and let some air bubbles ingressing into the reservoir till the back pressure decreases to a certain value. After the back pressure returns to the certain value, the pressure adjusting element further contacts the hole and prevents air from ingression, thus maintains a suitable back pressure of the ink in the reservoir.