Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
1998-12-04
2001-09-25
Barlow, John (Department: 2853)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
C347S058000
Reexamination Certificate
active
06293655
ABSTRACT:
FIELD OF THE INVENTION AND RELATED ART
The present invention relates to a liquid ejecting head for ejecting a desired liquid using generation of a bubble created by application of thermal energy to the liquid, a head cartridge and a liquid ejecting apparatus which use the liquid ejecting head.
The present invention is applicable to various apparatus such as a printer, a copying machine, a facsimile machine having a communication system, a word processor having a printer portion, or a printing apparatus, for industrial use, combined with various processing devices, which effect recording on recording materials such as paper, thread, fiber, textile, leather, metal, plastic resin material, glass, wood, ceramic material or the like.
Here, “recording” means recording of image having any sense such as letters, figures or the like, and recording of patterns not having particular sense.
An ink jet recording method or so-called bubble jet recording method is known wherein state change resulting in abrupt volume change is caused in the ink (generation of a bubble) by application of energy such as heat to the ink, and by the force provided by the state change, the ink is ejected from an ejection outlet, and is deposited on the recording material. A recording device using the bubble jet recording method generally comprises an ejection outlet for ejecting ink, an ink flow path in fluid communication with the ejection outlet, and an electrothermal transducer, as energy generating means, for ejecting the ink in the ink flow path, as disclosed in U.S. Pat. No. 4,723,129, for example.
Such a recording method is capable of printing high quality image at high speed and with low noise; the printing or recording head using the recording method, the ejection outlets for ejecting the ink can be arranged at high density, and therefore, high resolution image and particularly color image can be easily printed with small size machine. For this reason, the bubble jet recording method is recently used widely for printers, copying machines, facsimile machine machines or other office equipment, and even for industrial systems such as textile printing apparatus or the like.
The electrothermal transducer for generating energy for ejecting the ink can be manufactured through a semiconductor manufacturing process. Therefore, a conventional head using the bubble jet technique, comprises an element substrate (silicon substrate), electrothermal transducer formed thereon, and a groove for forming an ink flow path is formed thereon, and a top plate of resin material such as polysulfone or the like or glass or the like is combined thereon.
Utilizing the fact that element substrate is a silicon substrate, in addition to the electrothermal transducers, a driver for driving the electrothermal transducers, and a temperature sensor used to control the electrothermal transducers in accordance with the temperature of the head and a drive control portion or the like may be formed on the element substrate.
FIG. 20
, shows an example of such a structure of the element substrate. In
FIG. 20
, the element substrate
1001
is provided with heater array
1002
having a plurality of parallel electrothermal transducers for applying thermal energy for ink ejection, a driver circuit
1003
for driving the electrothermal transducers, image data transfer circuit
1004
for parallel transfer of the image data inputted serially from outside to a driver circuit
1003
, and an input contact
1007
for inputting the image data and various signals or the like from outside The element substrate
1001
is provided with a temperature sensor for sensing a temperature of the element substrate
1001
, a resistance sensor for sensing a resistance value of the electrothermal transducers, or another sensor
1006
, and a drive control portion
1005
for driving the sensor
1006
and for controlling a width of the driving pulse for the electrothermal transducers in accordance with an output from the sensor
1006
. A head having the driver, the temperature sensor and the drive control portion on the element substrate has been put in practical use, with high reliability of the recording head and small size.
However, recently, a higher image quality is demanded.
As a result of inventors investigations, the following points to be improved have been found, if the density of the ejection outlets and therefore the electrothermal transducers is increased in an attempt to improve the image quality, and the electrothermal transducers are further precisely controlled.
If the circuits for controlling the electrothermal transducers are all formed on the element substrate, the size of the element substrate is bulky with the result of bulky head.
When the ejection outlets are arranged at a high density such as 600 dpi or 1200 dpi or higher, precise alignment is required between the electrothermal transducers and ink flow paths, and the difference in the thermal-expansion between the element substrate and the top plate resulting from the heat during the driving of the electrothermal transducers, is not negligible.
In the case of a head capable of ejecting fine droplets (as a result of a high density arrangement of the ejection outlets, for example), if the heater is actuated when the ink is out, there is a liability that influence of the physical damage such as the surface damage of the heater to the ejection property is more significant than a conventional head ejecting larger droplets.
SUMMARY OF THE INVENTION
Accordingly, it is a principal object of the present invention to provide a liquid ejecting head, head cartridge and a recording device using the same which is small despite addition of various functions for controlling ejection of the liquid.
It is another object of the present invention to provide a liquid ejecting head wherein positional deviation due to the difference in the thermal-expansion between the element substrate and the top plate can be prevented.
It is a further object of the present invention to provide a liquid ejecting head wherein an ink detecting mechanism is provided to prevent the damage of the heater.
According to an aspect of the present invention, there is provided a liquid ejection head comprising a plurality of ejection outlets for ejecting liquid; a first substrate and a second substrate for constituting a plurality of liquid flow paths in fluid communication with said ejection outlets, respectively when combined with each other; a plurality of energy conversion elements disposed in said liquid flow paths, respectively to convert electrical energy to ejection energy for the liquid in said liquid flow paths; a plurality of elements or electric circuits having different functions for controlling driving conditions of said energy conversion elements; wherein said elements and electric circuits are provided either on said first substrate and said second substrate, depending on their functions.
The elements or the electric circuits are not concentrated on one of the substrates, so that liquid ejecting head is downsized.
The electrical connection with the outside are not effected by each of the function element and the electric circuit, but an outer contact for electrical connection of the element or the electric circuit with the outside is provided on either one of the first substrate and the second substrate, and the outer contact electrically connects the elements or electric circuits with outside on either one of the first substrate or second substrate, and a connection electrode for electrical connection of the elements or electric circuits on such surfaces of the first substrate and second substrate as are opposed to each other, so that they are electrically connected by combining the first substrate and the second substrate. Since the connection with the outside is concentrated on one of the substrates, further downsizing can be accomplished.
The selection may be such that such an element or electric circuit of all of the elements or electric circuits as are electrically connected to said energy conversion elements on individual
Hiroki Tomoyuki
Ikeda Masami
Imanaka Yoshiyuki
Ishinaga Hiroyuki
Kubota Masahiko
Barlow John
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Mouttet Blaise
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