Incremental printing of symbolic information – Ink jet – Controller
Reexamination Certificate
2001-07-02
2004-02-10
Hallacher, Craig (Department: 2853)
Incremental printing of symbolic information
Ink jet
Controller
Reexamination Certificate
active
06688720
ABSTRACT:
FIELD OF THE INVENTION AND RELATED ART
The present invention relates to an ink jet recording head for effecting image or the like printing by ejecting ink onto a recording material, a manufacturing method for the same, an ink jet recording apparatus and a driving method for an ink jet recording head. More particularly, it relates to an ink jet recording head in which a proper amount of energy is supplied to a recording element for generating energy contributable to ink ejection, a manufacturing method of the same, an ink jet recording apparatus using the same and actuating or driving method for the same.
A recording apparatus such as a printer, a copying machine, a facsimile machine or the like, or a recording apparatus as outputting equipment of a work station or a combined system including a computer, word processor or the like, effects recording of an image or the like on a recording sheet such as a sheet of paper, plastic thin plate (OHP for example) in accordance with image information. The recording apparatus is classified, depending on the recording method using recording means, into an ink jet type, a wire dot type, a thermosensitive type, a thermal transfer type, a laser beam type or the like.
Among them, the ink jet type recording device (ink jet recording apparatus) uses a recording means (recording head) from which the ink is ejected onto the recording sheet. This type is advantageous in that the size of the recording means is small, that high-speed printing with high resolution is possible, that plain paper is usable without special treatment thereto, that running cost is low, that noise is low (non-impact type), and color image printing is easy using a plurality of colors of ink.
The ink jet recording type is further classified into various types, in one of which a heat generating element is provided in a nozzle and is actuated to produce heat which is used to eject the ink (bubble jet recording system). The recording element for generating the energy to eject the ink can be manufactured through a semiconductor manufacturing process. Therefore, the recording head or the Bubble Jet type comprises an element substrate made of silicon substrate, a recording element formed thereon and a top plate of resin material such as polysulfone or glass or the like having grooves therein which constitute ink passages.
In some of the recording heads of this type, drivers for driving the recording elements, temperature sensors for controlling the recording elements in accordance with head temperatures and a drive control portion or the like are formed on the element substrate as well utilizing the material (silicon substrate) of the element substrate.
FIG. 9
shows an example of a substrate for the recording head.
In
FIG. 9
, formed in the element substrate
900
are a plurality of juxtaposed heat generating elements (recording elements)
901
for applying thermal energy for ink ejection, a power transistor (driver)
902
for driving the heat generating elements
901
, a shift register
904
for receiving serial image data supplied from an external device, a serial clock in synchronism therewith to receive the image data of 1 line at a time, a latching circuit
903
for latching the image data of one line outputted from the shift register
904
in synchronism with the latching clock signals and for parallel transfer thereof to the power transistor
902
, a plurality of AND gates
915
, provided corresponding to each of the power transistors
902
, for applying output signals of the latching circuit
903
to the power transistor
902
in accordance with external enabling signals
908
, and input contacts
905
-
912
for inputting the image data and various signals from the outside.
On the element substrate
900
, there are formed a temperature sensor reference numeral
914
for measuring a temperature of the element substrate
900
and a heater for heating the element substrate on the basis of the temperature detection of the element substrate
900
by the temperature sensor. U.S. Pat. No. 5,175,565, for example, discloses an element substrate in which the temperature sensor and the heater are built-in at the opposite outside portions of a recording element array. With this structure, the problem of such a temperature distribution of the element substrate
900
as will lead to unstable ink ejection can be avoided. That is, the temperature distribution is detected by the temperature sensor, and in response to the detection, the heater is actuated to correct the temperature distribution of the temperature. Thus, stabilized ink ejection is accomplished. A recording head having on the element substrate the driver, the temperature sensor, the drive control portion and so on, has been put into practice, and is advantageous in the reliability and the downsizing of the apparatus.
With this structure, the image data inputted as the serial signal are converted to the parallel signals by the shift register
904
, and are outputted and retained by the latching circuit
903
in synchronism with the latching clock signals. In such state, when a driving pulse signal for the heat generating element
901
(enabling signal
908
for the AND gate
915
) is inputted through the input contact
908
, the power transistor
902
is actuated in accordance with the image data to supply the electric current to the corresponding heat generating element
901
, thus heating the ink in the liquid flow path (nozzle), by which the ink is ejected in the form of a droplet through the nozzle.
However, the ink jet recording heads include differences among individuals due to the tolerances during the manufacturing step, and therefore, the driving voltage applied to a recording element may be higher than a driving voltage supplying a proper amount of energy with a result of shorter service life than expected, or conversely, the driving voltage applied to the recording element is smaller than the driving voltage supplying the proper amount of energy with a result of ejection defect.
U.S. Pat. No. 5,943,069 proposes using the temperature control heater as a resistance sensor, and the resistance of the heater is detected, and on the basis of the detected resistance, a proper driving voltage to be applied to the heat generating element
901
is selected. U.S. Pat. No. 5,943,069 also discloses that in consideration of the possibility that when the size of the substrate (element substrate) is large, because of variations of the resistance values of the heat generating elements (recording elements), a resistance sensor is built-in at each of opposite outside portions of the recording element array. The resistances of the resistance sensors are sequentially detected, and on the basis of the output, the driving voltage to be applied to the recording element is selected.
Recently, the number of nozzles of a recording head has increased in order to raise the recording speed, to such an extent that the length of the array of the nozzles (recording width) is 100 mm, or 200 mm (full-line type). However, in the development of long recording heads, it has turned out that the above-mentioned problems arise again when the recording width is increased. More particularly, even if the resistance sensors as disclosed in said U.S. Pat. No. 5,943,069 are used, some of the recording elements have shorter service lives, or some other recording elements have ejection defects.
The inventors first thought that problems could be solved by special use of the resistances of the two resistance sensors, although U.S. Pat. No. 5,943,069 did not disclose how to use the resistances sequentially detected by the two resistance sensors.
The inventors have noted the possibility that variations in the resistances of the recording elements are greater when the size of the substrate is large as pointed out by U.S. Pat. No. 5,943,069, and the inventors experiments and considerations have revealed that if the variations relative to a sheet resistance value is approx. 4%, the problems of the short service life and ejection defect do not arise, and the recording h
Imanaka Yoshiyuki
Mochizuki Muga
Okazaki Takeshi
Ozaki Teruo
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Hallacher Craig
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