Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
1996-08-29
2001-02-20
Le, N. (Department: 2861)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
Reexamination Certificate
active
06189997
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink jet recording apparatus and a method for operating such apparatus. More particularly, the invention relates to an ink jet recording apparatus that performs the recovery operation while in a recording operation, and a method for operating such apparatus.
2. Related Background Art
A recording apparatus, which is provided with the functions of a printer, a copying machine, a facsimile equipment, and the like, or a recording apparatus used as an output device for a complex type electronic equipment including a computer and a word-processor, or for a work station, is structured to record images on a paper sheet, a thin plastic plate, or some other recording material (recording medium) in accordance with image information. These recording apparatuses are divided into an ink jet type, a wire-dot type, a thermic type, a laser beam type, among others, depending on the recording method that each of them adopts for its recording operation.
Generally, in a serial type recording apparatus that scans in the direction substantially perpendicular to the feeding direction of a recording material (sub-scanning direction), a carriage having a recording head mounted on it serving as recording means travels on a recording material after the recording material has been set at a given recording position. In this way, images are recorded on the recording material in the main scanning direction.
Then, when a one-line portion is recorded, a sheet feed (pitch feed) for a given amount is performed. After that, recording is again executed in the main scanning direction to record images on the next line on the recording material, which is now at a standstill.
The operation described above is repeated to perform the entire recording on a recording material.
Of those recording apparatuses, an ink jet type recording apparatus (an ink jet recording apparatus) that records on a recording material by discharging ink from the recording head serving as recording means has the following advantages:
(1) Recording means can be easily formed compactly.
(2) A highly precise images can be recorded at high speeds.
(3) Recording is possible with respect to an ordinary paper sheet without providing any particular treatment for such paper sheet.
(4) Running costs are low.
(5) Being non-impact type, the apparatus makes lesser amount of noises.
(6) Color images can be recorded easily by use of multiple color ink.
Also, it is ease to record at a higher speed by use of the recording apparatus of line type having a line type recording head provided with a plurality of discharge ports arranged in the feeding direction (sub-scanning direction) of a recording material.
Further, with the recording apparatus wherein ink is discharged from the recording head downward almost in the vertical direction, no gravitation causes ink to curve when its flying is initiated. Therefore, it is possible to make the shooting accuracy of ink excellent with respect to a recording material, and to perform printing more precisely.
Of the ink jet recording apparatuses described above, the one having the ink jet type recording means (recording head) that discharges ink by the utilization of thermal energy can be produced easily through semiconductor fabrication processes, such as etching, deposition, sputtering, and so forth. This enables the film formation of electrothermal transducing elements, electrodes, walls of liquid paths, ceiling plate, and others on a base board, hence making it possible to provide a highly densified arrangement of liquid paths (discharge port arrangement), and to implement making recording means more compactly. Also, it becomes easier to provide a fully multiple recording means and assemble it in a higher density by the utilization of the well advanced IC technologies and micro-machining techniques, which facilitates the elongation and surfacing (two-dimensional arrangement) of recording means.
Nevertheless, in an ink jet recording apparatus of the kind, defective discharges (including disabled discharges) may take place in some cases if discharge ports are clogged by paper particles, dust particles, or some other foreign substances adhering to the ink discharge ports of the recording head or if ink is dried in the discharging portion to make it more viscous or cause it to be fixed thereto. Also, when a new ink cartridge or a new head cartridge is used for the first time, the condition of the ink paths from the discharge ports to the ink tank is not exactly regulated at all times. Therefore, in order to prevent the clogging or to keep the ink paths normal, there are provided cleaning means for removing foreign substances adhering to the ink discharge ports (discharge port formation surface) of a recording head or recovering means for normalizing the discharge ports and ink paths of a recording head.
As cleaning means, a mechanism is adopted to wipe off and clean the discharge port formation surface of a recording head mainly by use of a flexible wiper (wiping member). Also, as recovering means, a recovery device is adopted to cover the ink discharge ports of a recording head mainly by means of a cap when recording is at rest, and at the same time, to suck ink from the ink discharge ports by suction means, such as a pump, through the cap, thus normalizing the ink discharge ports and ink paths.
FIG. 4
is a view showing one structural example of an ink jet recording apparatus of serial type in accordance with the related background art.
As shown in
FIG. 4
, an apparatus exemplified here comprises at least a carrier roller
108
, which is connected to a recording sheet carrier motor (not shown) through a gear train and others of a driving force transmission mechanism
109
, and which carries a recording sheet
115
serving as a recording material; a sheet exhaust roller
112
connected to the carrier roller
108
through a driving force transmission gear train
113
, while being biased to a spur
114
by means of a biasing member (not shown); a pinch roller
110
rotatively supported on a pinch roller holder
111
, which is biased to the carrier roller
108
by means of a biasing member (not shown); a recording head
106
integrally formed with an ink tank, the ink discharge ports of which are arranged downward, serving as recording means for recording on the recording sheet
115
; a carriage
101
having the recording head
106
mounted thereon; a guide shaft
102
supporting the carriage
101
slidably in the direction orthogonal to the carrying direction of the recording sheet
115
, and also, in the direction parallel to the surface of the recording sheet
115
(in the direction indicated by arrows A in FIG.
4
); a carriage driving belt
105
to enable the carriage
101
to reciprocate in the straight-line direction; and a carriage driving motor
103
and a pulley
104
. Also, the recording head
106
is connected electrically to a control board (not shown) through a flexible board
107
.
Further, outside the recording area, there are provided a wiper
120
structured and interlocked with the movement of the carriage
101
to be able to contact with or part from the ink discharge ports of the recording head
106
in order to clean the recording head
106
; a pump
119
to execute the recovery operation of the ink discharge ports in order to keep the ink discharge performance of the recording head in normal condition; and a cap
118
conductively connected to a waste ink tank (not shown) through the pump
119
.
Now, the description will be given below as to the printing operation of an ink jet recording apparatus structured as described above:
At first, when a recording sheet
115
is inserted into a recording sheet inlet aperture (not shown) formed by guide members
116
and
117
, the recording sheet
115
is pinched by the carrier roller
108
and the pinch roller
110
. By the rotation of the carrier roller
108
, the recording sheet is carried over to the recording position facing the ink discharge ports of the recording head
Kanome Yuji
Takahashi Seiji
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Le N.
Nghiem Michael
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