WO2003039875A1

WO2003039875A1 - Inkjet printer

Info

Publication number: WO2003039875A1
Application number: PCT/KR2002/002072
Authority: WO
Inventors: Chul-Sik Ok
Original assignee: Hypernics Co., Ltd.
Priority date: 2001-11-07
Filing date: 2002-11-07
Publication date: 2003-05-15

Abstract

Disclosed is an ink jet printer system for performing lithographic printing by utilizing an ink dispensing device properly after plural ink jet heads are connected in parallel. The ink jet printer system includes: a printer head (10) part for jetting and printing ink onto ink jet material; and ultraviolet exposure devices (20) mounted at one side or both sides of the printer head part for drying the jetted ink directly. In another aspect, an ink jet printer system includes: an ink tank (110) for storing a predetermined amount of ink, an dispensing device (150) for receiving the ink from the ink tank and storing the ink temporarily, the ink dispensing device (150) providing the stored ink to the ink head (10), and a vacuum tank (190) connected to one side of the ink dispending device, the vacuum tank providing negative pressure to the ink dispensing device to prevent the ink from being supplied to the ink head rapidly. The ink jet printer system can perform printing onto not only general materials but also all-type materials, such as steel boards, glass and vinyl-based products, because the ink is dried directly by the exposure device (20) after the ink is jetted onto the material. Furthermore, the ink jet printer system can perform the lithographic printing easily by improving how to use an auxiliary ink container (30).

Description

INKJET PRINTER

Technical Field

The present invention relates to an inkjet printer system, and more particularly, to an inkjet printer system for performing lithographic printing by utilizing an ink dispensing device properly after plural inkjet heads are connected in parallel.

Background Art

In general, an inkjet system is a large-scale printer system, and has been used for printing large-scale objects to be printed, such as hanging banners and large-scale signboards.

Such a inkjet system essentially requires a main ink device and an auxiliary ink device.

The auxiliary ink device has a level controller so as to automatically control the level of ink of an auxiliary ink container and automatically supply the ink to the auxiliary ink container by receiving ink from a main ink container on demand. That is, the inkjet system adopts a method that the auxiliary ink device receives the ink from the main ink container when the ink of the auxiliary ink container is lowered to a predetermined level or less, and blocks the line between the main ink container and the auxiliary ink container when the ink of the auxiliary ink container is increased to the predetermined level or more.

Such a method is an ink dispensing method used for roll-type materials, and mainly used to soft materials, such as textile or paper, which are easily rolled on a roll. However, the ink supply method of osmotic pressure method, which needs the auxiliary ink container, is to supply ink to an ink head by natural gravity, and needs a continuous check of level of the ink during dispensing of the ink because the supply environment of the ink is changed according to a distance and a position of the ink supply line. Furthermore, even though a user checks the level ofthe ink, the ink drops frequently. That is, the auxiliary ink container is installed at a place spaced away from the ink head, but the place is not fixed exactly, and so, the amount of ink supplied is changed according to the installation environment of the auxiliary ink container. As a result, the conventional inkjet system has several problems in that the amount ofthe ink supplied to the ink head cannot be maintained uniformly and that the user must reprint due to stop of the supply of the ink because the system uses the osmotic pressure method.

The conventional inkjet system has other problems in that the user wants an unmanned printing but must always check the level of the ink at a place close to the inkjet printer system without leaving the place because of uneasiness in supply of the ink, and in that there occur enormous expenses in case of reprinting.

Furthermore, in case of lithographic printing for printing not the roll-type material but hard-type material, the conventional inkjet system cannot print using lithographic materials because the auxiliary ink container is located under the inkjet head.

Disclosure of Invention

Accordingly, the present invention is directed to an inkjet printer system that substantially obviates one or more problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide an inkjet printer system for performing lithographic printing by converting the structure of an auxiliary ink container. Another object of the present invention is to provide an inkjet printer system for supplying ink directly from a main ink container.

A further object of the present invention is to provide an inkjet printer system for drying a printed part directly by mounting an exposure device onto a printer head assembly. A still further object of the present invention is to provide an inkjet printer system for printing smoothly by having a white inkjet device.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described^" herein, an inkjet printer system includes: a printer head part for jetting and printing ink onto inkjet material; and ultraviolet exposure devices mounted at one side or both sides of the printer head part for drying the jetted ink directly.

In another aspect of the present invention, an inkjet printer system includes: an ink tank for storing a predetermined amount of ink; an ink dispensing device for receiving the ink from the ink tank and storing the ink temporarily, the ink dispensing device providing the stored ink to the ink head; and a vacuum tank connected to one side of the ink dispending device, the vacuum tank providing negative pressure to the ink dispensing device to prevent the ink from being supplied to the ink head rapidly.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation ofthe invention as claimed.

Brief Description ofthe Drawings

Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic view illustrating the configuration ofthe present invention; FIG.2 is a plan view of an inkjet head assembly of FIG. 1; FIG. 3 is a view of a preferred embodiment of the inkjet head assembly according to the present invention;

FIG. 4 is a schematic view illustrating the configuration of an auxiliary ink container according to the present invention;

FIG. 5 is one side view ofthe inkjet head assembly of FIG. 1; FIG. 6 is a view of a first embodiment of an exposure device according to the present mvention;

FIG. 7 is a view of a second embodiment of the exposure device according to the present invention;

FIG. 8 is a conceptual view illustrating operation of the exposure device according to the present invention; FIG. 9 is a schematic view illustrating the configuration of a lamp of the exposure device according to the present invention;

FIG. 10 is a view of a first embodiment of an ink supply line in a state that the auxiliary ink container is omitted; and FIG. 11 is a block diagram for explaining operation of essential components of the present invention;

FIG. 12 is a view of a second embodiment of the ink supply line in the state that the auxiliary ink container is omitted.

Best Mode for Carrying Out the Invention

The present invention will now be described in detail in connection with preferred embodiments with reference to the accompanying drawings. For reference, like reference characters designate corresponding parts throughout several views. Additionally, detailed description of the present mvention will be omitted if it is judged that the detailed description of relevant known functions or structures makes the point ofthe present invention obscure.

As shown in FIG. 1, the present invention includes a printer head assembly 100, a printer table 200 and a material-guiding roller 300, and can further include an auxiliary flat table 400 when flat-type material is printed.

The printer head assembly 100 guides and moves the printer table 200 to a supporter 201 and a rod slider 202. At this time, the material enters through the material guiding roller 300, and printing patterns are formed on the material by the ink liquid jetted from the printer head 10 when the material passes a flat operation area. The present invention performs printing by passing relatively thin paper or textile material using the roller 300, and in case of the flat material, forms the printing patterns onto the flat material using the auxiliary flat table 400.

Meanwhile, as shown in FIG. 2, the printer head assembly 100 includes: a printer head part 10 provided with blue ink, red ink, yellow ink, black ink and white ink; and ultraviolet exposure devices 20 located at both sides of the printer head part for directly drying the jetted ink.

In the present mvention having the above structure, the printer head part 10 and the ultraviolet exposure device 20 are inserted into one print assembly 100, and the print assembly, on which plural printers are loaded, is guided and moved by the rod slider 202.

The blue, red, yellow, black and white inks are jetted through the printer head part 10. For this, the structure ofthe printer head part is embodied in two types.

First, the printer head part 10 has five printer heads, i.e., a blue printer head 11, a red printer head 12, a yellow printer head 13, a black printer head 14 and a white printer head 15.

The printer head part 10 can coat each colored ink, and especially, the present invention provides a feature that white color is coated through a white printer head.

As described in the present invention, the present invention has an advantage that a desired image can be printed directly on textile of an opaque color if the white color is coated.

Conventionally, to express a user's own face on the center of black background, black color must be entirely printed on an exclusive material of white background, but it is not good in aspects of an ink consumption amount or a printing period. So, the conventional system has a disadvantage in that the system requires lots of printing processes because the printed images are attached onto products through a laminating coating process. However, the present invention can print directly the user's own face by fixing a desired position on the textile of black background because of use of the white ink.

Finally, the present invention can finish the printing work directly without additional processes because the image can be printed directly on the lighter surface.

As shown in FIG. 2, the printer head part 10 has the five printer heads a blue printer head 11 for jetting and printing blue ink onto an inkjet material, a red printer head 12 for jetting and printing red ink onto the inkjet material, a yellow printer head 13 for jetting and printing yellow ink onto the inkjet material, a black printer head 14 for jetting and printing black ink onto the inkjet material, and a white printer head 15 for jetting and printing white ink onto the inkjet material. To arrange the printer heads suitable for the size of the printer head assembly 100, four printer heads 11, 12, 13 and 14 ofthe printer head part 10 are arranged obliquely and the last white printer head 15 is arranged in a line with the printer head next to the last printer head. At this time, the printer heads can be arranged in any directions except the horizontal direction. Therefore, four printer heads are arranged in a line, and then, the last layer can be arranged at any position ofthe line.

Meanwhile, the structure of the printer head part 10, which can perform white- color printing, can be realized by four printer heads as shown in FIG. 3. That is, the printer head part 10 may include a first printer head 16 for dispensing white color through three fountain nozzles and dispensing one of blue, red and yellow colors through the other fountain nozzle, a second printer head 17 having two fountain nozzles of the color selected in the last layer of the first printer head 16 and two fountain nozzles of one color selected from the remaining, a third printer head 18 having a fountain nozzle of the color selected in the last layer of the second printer head 17 and three fountain nozzles of one color selected from the remaining selected from the first and second printer heads 16 and 17, and a fourth printer head 19 having three fountain nozzles of the remaining color selected by the first, second and third printer heads 16, 17 and 18 and blocking the remaining one fountain nozzle. Each printer head has four fountain nozzles a, b, c and d. If the printer heads are arranged in a straight line, totally 16 fountain nozzles are arranged without overlapping. Here, if three fountain nozzles are distributed to one color, totally, 15 fountain nozzles have colors respectively, but the remaining one is blocked.

In the present invention, 15 fountain nozzles of 16 fountain nozzles are dispersed and arranged in the four printer heads, and three fountain nozzles have the same color continuously.

Therefore, the present invention can perform printing work at a time without regard to the background color.

Meanwhile, the present invention can print not only the roll-type material but also the flat-type material. For this, an auxiliary ink container 30 is mounted at a position higher than an ink-jetting surface. As shown in FIG. 4, in the auxiliary ink container 30, the reference numeral 32 designates an ink-receiving pipe for receiving the ink from a main ink container (not shown), 33 designates an ink-absorbing pipe for supplying ink to the printer head, 34 designates a level sensor for receiving the ink from the main ink container if the level of the ink is less than a predetermined level, and 35 indicates presently remaining ink liquid.

That the auxiliary ink container 30 is mounted at the position higher than the ink jetting surface is to prevent the flat-type material from touching the auxiliary ink container when the flat-type material passes. In FIG. 1, the lower portion of the auxiliary ink container is mounted at a place higher than the jetting surface ofthe printer. If the system is configured only in the roll-type, even though the jetting surface of the nozzle and the auxiliary ink container are located at the same height, there is no problem because the printing material is very thin. However, to perform the lithographic printing, the auxiliary ink container must be arranged at the position higher than the thickness of a flat plate.

Therefore, the auxiliary ink container 30 is arranged at the position higher than the flat-type printing material, and thereby, the ink is not supplied at a time but supplied slowly through a sponge 31.

If there is not the sponge 31, the auxiliary ink container 30 is arranged at the position higher than the printer head part 10, and the ink may be supplied continuously to the printer head 10 by gravity function. As in the present invention, the ink is supplied through the sponge 31, the sponge 31 reduces pressure of the ink and makes the ink ofthe printer head 10 be supplied slowly as much as it is jetted.

Therefore, the present invention can supply the ink smoothly from the auxiliary ink container without touch of the auxiliary ink container during the lithographic printing because the ink is jetted slowly.

As shown in FIGS. 2 and 5, the printer head assembly 100 has ultraviolet drying lamps at both sides as the exposure devices 20. If the ultraviolet drying lamps are used, the ink is dried directly after the ink is jetted, and so, the present mvention can print nearly all materials including soft-surface materials like vinyl. The non- explained reference numeral 21 designates a cooling fan for emitting heat generated from the exposure device to the outside.

FIG. 6 is a detailed view for showing the exposure device 20. The ultraviolet exposure device 20 of the present invention includes a lamp case 22 for having a lamp disposed within, the cooling fan 21 for emitting heat generated from the lamp to the outside, and an ultraviolet lamp connector 24 and a cooling fan connector 25. The non-explained reference numeral 23 designates a cooling fan fixture.

FIG. 6 shows that the cooling fan 21 is mounted on the upper portion of the exposure device, but the cooling fan 21 may be mounted at one side of the exposure device as shown in FIG. 7.

That is, it does not matter if the cooling fan 21 can emit the heat to the outside without regard to the mounted position of the cooling fan, either the side surface or the upper surface ofthe exposure device.

As shown in FIG. 8, the lamp case 22 can prevent deformation of a subject by emitting the heat(infrared rays), which is generated when the ultraviolet lamp emits light, to the outside using a heating-line cut film 27 and a mirror 28 of the lower end of the lamp case 22, and by maximizing an ultraviolet reflecting effect.

It is preferable that the lamp 26 (see FIGS. 8 and 9) used in the exposure device 20 is a high-pressure mercury lamp, and that wavelength of ultraviolet rays is about 365nm.

Lamps emitting ultraviolet rays are divided into a metal halide lamp and the high-pressure mercury lamp, but, in the present invention, the high-pressure mercury lamp, which is generally and widely used in the industrial field, is used.

Here, the unit of ultraviolet ray is expressed by nanometer(nm), and lnm means a billionths meter. At this time, the wavelength is reduced if the numeral value of nanometer is reduced, and increased if the numeral value of nanometer is increased. The wavelength of ultraviolet ray is about 200 ~ 470nm.

The wavelength of ultraviolet ray suitable for the printing work is 350 ~ 375nm, and in the present mvention, the ultraviolet lamp having the wavelength of about 365nm is used. The ultraviolet exposure device 20 is mounted in a direction that the inkjet material is transferred, and exposes ultraviolet rays at the corresponding position and dries instantaneously during scanning of the printing material, and thereby, the present invention can realize perfect colors through repeated reciprocating motions. Meanwhile, in another embodiment of the present invention, there is a method for inducing a stable jet of the ink by removing the auxiliary ink container and maintaining the inside pressure uniformly using pneumatic pressure. FIG. 10 shows the embodiment. As shown in the drawing, the system includes a first air pump 120, a main ink tank 110, an ink dispensing device 150, a vacuum tank 190 and a second air pump 90.

The main ink tank 110 stores a predetermined amount of ink, and the ink stored in the main ink tank 110 is transferred to the ink dispensing device 150 using the first air pump 120.

The first air pump 120 can provide positive pressure of a predetermined amount, and transfers the ink through a pipe line extending from the other side of the main ink tank by inserting the air into one side ofthe main ink tank 110.

At this time, a first pressure sensor 130 is mounted on the pipe line between the first air pump 120 and the main ink tank 110, and makes the ink be dispensed at a uniform speed by maintaining the inside pressure ofthe main ink tank 110 uniformly. The ink dispensing device 150 receiving the ink from the main ink tank 110 divides the supplied ink to four channels to supply the ink to the ink head 10, and checks pressure of the stored ink to provide data for controlling positive pressure and negative pressure tools.

That is, the level sensor 160 checks the amount of the ink stored in the ink dispensing device 150, so that the ink dispensing device 150 is supplied with the ink from the main ink tank 110 if the amount ofthe ink is less than the predetermined level, and the inside of the ink dispensing device 150 always maintains the uniform negative pressure using the negative pressure ofthe vacuum tank 190.

At this time, the negative pressure occurs by removing the inside air of the vacuum tank 190 using the second air pump 90. The inside pressure of the vacuum tank can be maintained uniformly by checking the inside pressure of the vacuum tank 190 through the second pressure sensor 180 and controlling the operation of the second air pump 90, and thereby, the ink dispensing device 150 can maintain the negative pressure in a proper condition. Finally, as described above, the present invention transfers the the predetermined amount of ink from the main ink tank 110 to the ink dispensing device 150 using the positive pressure provided from the first air pump 120, and the inside pressure of the ink dispensing device 150 prevents the ink inside the ink dispensing device 150 from flowing from the head using the negative pressure provided from the vacuum tank 190. Therefore, it can be prevented that the supplied ink flows into the ink head 10 rapidly.

The above is compared with the conventional system, which supplies ink through an osmotic pressure method. The osmotic pressure method supplies the ink through the auxiliary ink container, but the present invention provides the negative pressure to supply the ink slowly as much as it is needed. Therefore, in the present invention, the ink is gathered in the upper portion of the ink head 10 and the position of the ink is fixed, so that there is no need of the auxiliary ink container, and that the present invention can perform the lithographic printing without obstruction to the printing material during the lithographic printing. The present invention can be removed perfectly fine bubbles of the inside of the ink head 10 by maintaining the uniform level and supply of the ink using the pneumatic pressure, thereby increasing safety in printing.

That is, because the negative pressure is always provided to the inside ofthe ink dispensing device 150, the air is not mixed in the ink dispensed by the fine bubbles absorbed upwardly, so that the ink of the uniform amount is always supplied for the precise printing.

FIGS. 10 and 11 are block diagrams showing a circuit structure of the present invention. As shown in the drawings, to input data, there are the first pressure sensor

130 for checking the pneumatic pressure, the second pressure sensor 180 for checking vacuum pressure and the level sensor 160 for checking the amount of the ink of the ink dispensing device.

The data measured in the sensor 160 is inputted to a controller 80. The controller 80 controls a 3-way valve 170, a solenoid valve 140, the first air pump 120 and the second air pump 90 on the basis of a data value inputted from the sensors 130, 160 and 180. That is, the controller 80 checks the positive pressure through the first pressure sensor 130 to provide the uniform positive pressure to the main ink tank 110, and checks the negative pressure through the second pressure sensor 180 and controls the second air pump 90 to always maintain the uniform negative pressure inside the ink dispensing device 150. If the negative pressure is needed more, the controller operates the second air pump 90.

As a result of output of the level sensor 160, if the amount of the ink of the ink dispensing device 150 is lowered to a predetermined amount or less, the controller 80 operates the solenoid valve 140 to receive the ink from the main ink tank 110.

Because the ink dispensing device 150 is in a vacuum condition, when the ink is supplied to the ink dispensing device, the controller must operate the second air pump 90 to generate more vacuum pressure through the vacuum tank to deflate the ink dispensing device.

The 3-way valve 170 is connected to dispensing lines of the vacuum tank 190, the ink dispensing device 150 and the first air pump 130. The positive pressure is supplied to the ink dispensing device 150 through the 3-way valve 170 because the ink must be permeated into the ink head 10 at the time of an initial ink setting. After that, only the line of the vacuum tank 190 is connected to the ink dispensing device 150 to always maintain the uniform negative pressure.

FIG. 12 shows another embodiment of FIG. 10. In FIG. 12, the kernel of the system is that the pressure of the ink supplied to the inside of the printer head is maintained suitable for the jet condition ofthe printer head using the uniform pneumatic pressure (positive pressure and negative pressure) without using the auxiliary ink container so as to induce the smooth fountain ofthe ink.

In FIG. 12, there are the main ink tank 110, a solenoid pump 210, the ink dispensing device 150, a vacuum generator 260 and a compressor 280, as essential components.

That is, the compressor 280 is supplied to the solenoid pump 210 to provide a pumping function, so that the ink inside the main ink tank 110 is supplied to the ink dispensing device 150. The ink dispensing device 150 provides the ink to the ink head 10 to j et the ink liquid to the subj ect.

At this time, the amount of the supplied ink is restricted by controlling a check valve 220 mounted between the solenoid pump 210 and the ink dispensing device 150 after the proximity sensor 160 checks it.

Furthermore, the check valve 220 blocks the line ofthe ink supplied by a signal of the proximity sensor 160 to induce the ink dispensing device 150 to have a uniform pressure, and checks the remaining ink of the ink dispensing device 150 using data of the proximity sensor 160 to control the operation of the solenoid pump 210 to prevent overflow ofthe ink.

Moreover, like the first embodiment, the second embodiment of the present mvention provides the negative pressure to the inside of the ink dispensing device 150 to prevent the ink inside the ink dispensing device 150 from being supplied to the ink head rapidly. When the positive pressure generated from the compressor 280 is supplied to the vacuum generator 260 through the solenoid valve 270, the vacuum generator 260 generates vacuum, and thereby, the negative pressure is generated. At this time, the generated negative pressure checks the inside pressure of the ink dispensing device 150 using the vacuum pressure sensor 230 and blocks the solenoid valve 240. At this time, a predetermined negative pressure is applied to a vacuum regulator 250 to absorb the inside pressure of the ink dispensing device 150, so that the inside of the ink dispensing device 150 is controlled to have the uniform negative pressure.

Finally, all parts of the system are operated through the above processes, and thereby, the inside pressure of the ink dispensing device is controlled without drop of the ink using the uniform supply and negative pressure of the ink. As a result, the present mvention can develop the lithographic inkjet without the auxiliary ink container. Therefore, the inkjet printer system according to the present invention can print the flat-type material without the auxiliary ink container, and can secure safety in printing by absorbing the fine bubbles of the inside of the ink using the negative pressure as in the first embodiment. Industrial Applicability

As described above, the inkjet printer system according to the present invention can perform printing onto not only general materials but also all-type materials, such as steel boards, glass and vinyl-based products, because the ink is dried directly by the exposure device after the ink is jetted onto the material.

Furthermore, the present invention can perform the lithographic printing easily by improving how to use an auxiliary ink container.

Additionally, the present invention can reduce manpower cost and simplify the entire process of printing because it can perform printing work directly without regard to background color.

While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.

Claims

Claims:

1. An inkjet printer system comprising: a printer head part for jetting and printing ink onto inkjet material; and ultraviolet exposure devices mounted at one side or both sides of the printer head part for drying the jetted ink directly.

2. The inkjet printer system according to claim 1, wherein the printer head part and the ultraviolet exposure devices are enclosed in a case.

3. The inlcjet printer system according to claim 2, wherein a lamp applied to the ultraviolet exposure device is a high-pressure mercury lamp.

4. The inkjet printer system according to claim 3, wherein the ultraviolet lamp emits light having wavelength of about 365nm.

5. The inkjet printer system according to claim 1, wherein the printer head part includes: a blue printer head for jetting blue ink onto the inlcjet material; a red printer head for jetting red ink onto the inkjet material; a yellow printer head for jetting yellow ink onto the inkjet material; a black printer head for jetting black ink onto the inkjet material; and a white printer head for jetting white ink onto the inkjet material.

6. The inkjet printer system according to claim 1 or 5, wherein the printer head has four fountain nozzles.

7. The inkjet printer system according to claim 6, wherein the four fountain nozzles of one printer head is provided with ink of two colors to dispense two colors.

8. The inkjet printer system according to claim 1, wherein the printer head part further includes an auxiliary ink container mounted at one end thereof, the auxiliary ink container having a sponge disposed between the ink and the nozzle.

9. The inkjet printer system according to claim 8, wherein the auxiliary ink container is mounted at a position higher than the printer head.

10. An inkj et printer system comprising: an ink tank for storing a predetermined amount of ink; an ink dispensing device for receiving the ink from the ink tank and storing the ink temporarily, the ink dispensing device providing the stored ink to the ink head; and a vacuum tank connected to one side of the ink dispending device, the vacuum tank providing negative pressure to the ink dispensing device to prevent the ink from being supplied to the ink head rapidly.

11. The inkjet printer system according to claim 10, wherein a solenoid valve for restricting transfer of the ink is mounted between the ink tank and the ink dispensing device.

12. The inkjet printer system according to claim 10, wherein the ink tank further includes an air pump for providing air pressure, and a 3-way valve is mounted among the air pump, the ink dispensing device and the vacuum tank to maintain the uniform pressure ofthe ink dispensing device.

13. The inkjet printer system according to claim 12, wherein a sensor is mounted between the air pump and the vacuum tank to sense air pressure.

14. The inkjet printer system according to claim 10, wherein the ink dispensing device further includes a level sensor for checking the amount ofthe ink.