Incremental printing of symbolic information – Ink jet – Controller
Reexamination Certificate
2002-08-26
2004-07-13
Nguyen, Lamson D (Department: 2853)
Incremental printing of symbolic information
Ink jet
Controller
C347S057000
Reexamination Certificate
active
06761424
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an image print apparatus, control method thereof, and storage medium and, more particularly, to an ink-jet print apparatus having a print element which can control a printhead at a stable voltage, a control method thereof, and a storage medium.
BACKGROUND OF THE INVENTION
A printer which prints desired information such as a character or image on a sheet-like print medium such as paper or film is proposed as an information output apparatus for a word-processor, personal computer, facsimile apparatus, and the like.
Various methods are known for use as the print method of the printer. In recent years, an ink-jet method has especially received a great deal of attention because this method can print information on a print medium such as a sheet in a non-contact manner, can easily print color information, and generates little noise. A general ink-jet arrangement adopts a serial print method because of easy reduction in cost and size. According to this method, a printhead which discharges ink in accordance with desired print information is mounted. The printhead prints information while being reciprocally scanned in a direction perpendicular to the feed direction of a print medium such as a sheet.
The ink-jet printer realizes high-definition, high-quality printing by decreasing the volume of ink droplets discharged from the nozzles of the printhead.
In order to decrease the volume of ink droplets and achieve high-speed printing, the drive voltage of a print element which causes each nozzle of the printhead to discharge an ink droplet must be controlled as stably as possible. For this purpose, e.g., an electrolytic capacitor is generally set as a means for reducing voltage variations near the printhead having the print element.
When the printhead is to be exchanged, a printhead drive voltage and logic drive voltage are so stopped as not to apply any power to the contact between the printhead and a carriage which holds the printhead in order to allow the user to safely exchange the printhead. Then, the printhead is moved to a printhead exchange position.
At this time, charges accumulated in the electrolytic capacitor near the printhead having the print element are removed. For this purpose, a discharge resistor and a switching unit such as a switch are arranged on the printhead, and charges accumulated in the electrolytic capacitor are removed using the discharge resistor. When the drive voltage is stopped, a line connected to the electrolytic capacitor is connected to the discharge resistor by the switching unit, and charges accumulated in the electrolytic capacitor are safely removed.
As printers become less expensive, the discharge resistor and switching unit, which increase the cost, are being eliminated from the printhead. Such a printhead does not have any discharge resistor which removes charges accumulated in the electrolytic capacitor. After charges accumulated in the electrolytic capacitor spontaneously disappear, the printhead is moved to a printhead exchange position.
However, the printhead equipped with no discharge resistor which removes charges accumulated in the electrolytic capacitor requires a longer spontaneous discharge time as the electrolytic capacitor has a larger capacitance. It takes a longer time than the conventional printhead to move the printhead to a printhead exchange position after the user presses the exchange start button of the printer in order to exchange the printhead. This leads to a long work time when the user exchanges the printhead.
SUMMARY OF THE INVENTION
The present invention has been made to overcome the conventional drawbacks, and has as its object to provide an image print apparatus capable of quickly reducing, with a low-cost arrangement, charges accumulated in a capacitor serving as a means for reducing variations in printhead voltage, and a control method thereof.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.
REFERENCES:
patent: 4151558 (1979-04-01), Manners
patent: 4313124 (1982-01-01), Hara
patent: 4345262 (1982-08-01), Shirato et al.
patent: 4459600 (1984-07-01), Sato et al.
patent: 4463359 (1984-07-01), Ayata et al.
patent: 4558333 (1985-12-01), Sugitani et al.
patent: 4723129 (1988-02-01), Endo et al.
patent: 4740796 (1988-04-01), Endo et al.
patent: 5426454 (1995-06-01), Hosono et al.
patent: 5896146 (1999-04-01), Murata et al.
patent: 5912693 (1999-06-01), Katsuma et al.
patent: 5940097 (1999-08-01), Imai
patent: 6199969 (2001-03-01), Haflinger et al.
patent: 1 078 750 (2001-02-01), None
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Nguyen Lamson D
LandOfFree
Image print apparatus and control method thereof does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Image print apparatus and control method thereof, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Image print apparatus and control method thereof will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3246164