Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
2001-08-30
2003-03-11
Barlow, John (Department: 2853)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
Reexamination Certificate
active
06530641
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a liquid discharge head unit used for a liquid discharge apparatus that performs recording operation by discharging liquid, such as ink, from discharge ports in the form of liquid droplets. The invention also relates to a head cartridge and a method for manufacturing a liquid discharge head unit as well. In this respect, the liquid discharge head unit of the invention is applicable to a copying machine, a facsimile equipment having communication systems, a word processor having a printing unit, besides a printing apparatus generally used. Further, the invention is applicable to a recording system for industrial use which is provided with various kinds of processing apparatuses complexly combined therein.
2. Related Background Art
The liquid discharge apparatus (ink jet recording apparatus) is a recording apparatus of the so-called non-impact recording type, which makes it possible to record on various kinds of recording mediums at high speed. With the advantages such as to make almost no noises in printing, the liquid discharge apparatus is widely adopted for a printer, a copying machine, a facsimile equipment, a word processor, or the like that carries a recording mechanism.
As the typical liquid discharge method for a liquid discharge head to be mounted on a liquid discharge apparatus of the kind, there have been known the one that uses electromechanical converting device, such as piezo-element; the one that uses the irradiation of laser or other electromagnetic waves in order to discharge liquid droplets by the heating thereof; or the one that discharges liquid droplets by the action of film boiling generated by heat given to liquid by use of electrothermal converting devices (heaters) each having a heating resistive element therefor. The liquid discharge head, which uses electrothermal converting devices as discharge energy generating elements, is provided with electrothermal converting devices arranged in the liquid flow paths, respectively, and when electric pulses are applied to them for generating heat, thermal energy is given to ink. By the utilization of the bubbling pressure of liquid at the time of bubbling (boiling) exerted by the phaseal changes of liquid then, fine liquid droplets are discharged from fine discharge ports to record on a recording medium. In general, the liquid discharge head comprises discharge ports for discharging liquid droplets, and a supply system for supplying ink to these discharge ports.
The liquid discharge apparatus that uses the electrothermal converting devices described above has advantages in that it is relatively easy to perform image recording in high image quality and in high precision, and also, relatively easy to arrange the structure whereby to record images in colors. While the liquid discharge apparatus of the kind is being manufactured, it is demanded more to make the recording apparatus itself smaller. To meet such demand, there is used a head cartridge which is integrally formed compactly by a liquid discharge head and a liquid retaining portion that retains liquid to be supplied to the head.
The head cartridge of the kind may be provided with a liquid retaining portion capable of retaining ink of plural colors for the formation of color image or with a liquid retaining portion having liquid containers arranged to be exchangeable when ink has been consumed in order to reduce the running costs thereof. Also, it is known to use the liquid discharge head chip as a liquid discharge head which is compactly structured by bonding an orifice plate having discharge ports formed therefor to an element base plate having fine heaters, liquid flow paths, and others formed thereon. Then, this liquid discharge head chip is incorporated in the liquid discharge head unit provided with means for holding the chip in a designated position, and liquid supply means for conducting liquid from the liquid retaining portion to the liquid discharge head, among some others. This unit is bonded to the liquid retaining portion to structure a head cartridge unit. The liquid discharge head unit used for color image recording has a plurality of liquid discharge head chips incorporated in order to discharge ink of each color. Also, there may be a plurality of liquid discharge head chips incorporated in the liquid discharge head unit for the purpose of speeding up the recording operation.
However, for the liquid discharge head unit of the kind, it is required to position the liquid discharge head chip, the position of the discharge ports in particular, in high precision with respect to the liquid discharge apparatus main body so that liquid can be discharged to the appropriate positions for recording highly precise images.
Also, when the liquid discharge head unit is bonded to the liquid retaining portion or when the head unit is installed on the liquid discharge apparatus main body, there is a fear that the orifice plate is caused to be deformed or present some other defects if external force is given to the liquid discharge port formation surface, thus producing unfavorable effect on the preciseness of liquid discharges.
SUMMARY OF THE INVENTION
Therefore, the present invention aims at the provision of a liquid discharge head unit capable of positioning the discharge ports to a liquid discharge apparatus main body in high precision for executing highly precise liquid discharges, and also, aims at the provision of a head cartridge, as well as a method for manufacturing such liquid discharge head unit.
Also, it is another object of the present invention to provide a liquid discharge head unit capable of preventing external force from being exerted on the liquid discharge formation surface in order to avoid producing adverse effect on the preciseness of liquid discharges, and also, to provide a head cartridge, as well as a method for manufacturing such liquid discharge head unit.
In order to achieve these objects, the liquid discharge head unit of the present invention comprises a base plate having the installation reference used as positioning reference for the installation thereof on a liquid discharge apparatus main body; a frame connected to the base plate, having liquid supply paths formed therein for conducting liquid, and liquid supply ports communicated with the liquid supply paths open to side portion; a chip unit provided with discharge energy generating elements for heating the liquid to be bubbled and discharged, discharge ports for discharging the liquid, and liquid receiving ports for receiving the liquid into the interior thereof, and connected to the frame in a state of abutting against the side portion of the frame so as to enable the liquid supply ports and the liquid receiving ports to be communicated; and a front cap having opening portion to enable the discharge ports to be exposed to the outside, being arranged to cover the chip unit and the frame by covering at least the surface having the discharge ports open thereto, and connected to the chip unit and the frame.
With the structure thus arranged, the frame abuts against the base plate to be connected to the base plate in a state where the frame is in the relative positions designated for the installation reference, and further, the chip unit can abut against the side portion of this frame to be connected to the frame in a state of being in the relative positions designated for the installation reference, hence making it easier to position the discharge ports open to the chip unit in high precision with respect to the installation reference. Consequently, the position of the discharge ports can be arranged in high precision with respect to the liquid discharge apparatus main body to make it possible to structure a liquid discharge head unit capable of executing highly precise liquid discharges.
Also, with the provision of the front cap, it becomes possible to protect the liquid discharge surface from the external force that may be exerted on the discharge port formation surface, and avoid the adver
Kigami Hiroyuki
Koizumi Yutaka
Ohashi Tetsuya
Ono Takayuki
Shimazu Satoshi
Barlow John
Mouttet Blaise
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