JP2000052566A - Ink-jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To speedily and surely perform maintenance to an ink-jet nozzle with reducing a consumption of ink. SOLUTION: The ink-jet printer has an ink-pressuring holding means 50 interposed in the middle of an ink feed pipe 31 which can pressure and hold a pressure of the ink supplied from an ink feed pump 32 by utilizing an elastic deformation of a constituting member 57, a maintenance preparation control means 70 which can switch an outlet valve 65 to a shut state and an inlet valve 61 to an open state at a first selection time and can drive the ink feed pump 32 to supply the ink, and a maintenance execution control means 70 which controls to switch the inlet valve 61 to the shut state and the outlet valve 65 to the open state at a second selection time so that the pressured ink can be supplied to each ink-jet nozzle from the ink-pressuring holding means 50. Maintenance can be carried out all at once to the ink-jet nozzles while the pressured ink is supplied like a shock to a nozzle head with the utilization of an elastic restoration of the member 57 constituting the ink-pressuring holding means 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer capable of printing while supplying ink from an ink tank to a nozzle head having a plurality of ink jet nozzles through an ink supply pipe.

[0002]

2. Description of the Related Art A conventional serial type ink jet printer shown in FIG. 5 has a carrier 101 which can reciprocate along a guide bar 100, a nozzle head 20P having a large ink cassette mounted thereon, and a medium (paper).
Nozzle head 20 in row (X) direction (left and right direction in the figure) of P
An image is formed while jetting (discharging) ink from each inkjet nozzle while moving P. Each inkjet nozzle for each color ink of the nozzle head 20P is X
Each direction is single. Thus, for example, A
10 minutes (0.1PPM) for 4 size 1 color printing
Take it.

On the other hand, there has been proposed an ink jet printer capable of increasing the printing speed of, for example, 20 PPM (for example, Japanese Patent Application No. 8-296959).

In FIG. 6, each ink-jet nozzle of a nozzle unit (20C, 20Y, 20M, 20B) for each color (cyan, yellow, magenta, black) forming a nozzle head 20 is a rotating nozzle for carrying a medium (paper P). In the longitudinal direction [row direction (X)] of the body 10, for example, a large number (for example, a pitch equivalent to a resolution (300 dpi) or a pitch 2 to 4 times the pitch equivalent to the resolution (for example,
"2000"), and can be reciprocated in the X direction by being stationary in the X direction or by the alignment pitch of the inkjet nozzles.

Here, the rotating body 10 has a medium (P) carried on its outer peripheral surface, for
It can rotate in the R direction at pm. Thus, by rotating the medium (P) and performing the printing operation, for example, one A4 sheet can be printed in color in a few seconds.

In addition, compared to the conventional serial type, the nozzle head 20 is almost in a stationary state and the ink cassette does not need to be mounted integrally with the nozzle head 20, so that a large amount of ink can be filled. Since a separate ink tank is used and ink is supplied from the ink tank to the nozzle head 20 through an ink supply pipe, a large number (for example,
“800”) sheets can be printed continuously.

[0007]

By the way, in the previously proposed ink jet printer, maintenance (purge, etc.) for preventing clogging of the ink jet nozzle and removing gas (bubbles) is performed in comparison with the conventional serial type. More important. This maintenance is performed by discharging ink from each inkjet nozzle during non-printing. Therefore, as the number of inkjet nozzles increases, the capacity of the ink supply pump must be increased for maintenance and a large amount of ink must be supplied to the nozzle head 20, resulting in large size and high cost.

[0008] Thus, in order to further spread the use, it is important to develop a small and low-cost means for maintaining the inkjet nozzle.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet printer which is small and inexpensive, and which can quickly and reliably maintain ink jet nozzles while reducing ink consumption.

[0010]

It is rare that clogging occurs simultaneously in all of the ink jet nozzles. However, it is technically and temporally difficult to find (detect) only the clogged inkjet nozzles and perform maintenance only on them.

Therefore, in practice, maintenance is performed on all the ink jet nozzles without individually detecting the necessity of maintenance. However, the flow resistance of an inkjet nozzle that really needs to be cleared is large, and the flow resistance of an unclogged inkjet nozzle is small. Thus, no matter how much ink is supplied, the supplied ink passes through many unclogged ink jet nozzles, so that it is difficult to effectively perform maintenance.

In other words, according to the structure of the ink jet nozzle, even though the ink passes through the ink jet nozzle which is not clogged, the discharge amount per unit time does not suddenly increase. Even if the ink pressure is increased, it does not increase sharply. Therefore, effective supply of ink can be ensured by supplying a high-pressure ink in a short period of time as compared with the printing operation.
That said, a special maintenance pressurizing means,
Providing piping or the like is disadvantageous.

The present invention is based on the above analysis through experiments and researches, and is based on a normal ink supply system, so that pressurized ink can be supplied to all the ink jet nozzles instantaneously and with high impact simultaneously. is there.

According to a first aspect of the present invention, there is provided an ink jet printer capable of printing while supplying ink from an ink tank to a nozzle head having a plurality of ink jet nozzles through an ink supply pipe, wherein the printer is interposed in the middle of the ink supply pipe. Ink pressure holding means capable of holding the pressure of the ink supplied from the ink supply pump by utilizing the elastic deformation of the member, and provided in the ink supply pipe upstream of the ink pressure holding means. An inlet valve, an outlet valve provided in the ink supply pipe on the downstream side of the inlet valve, and an ink supply pump which can switch the outlet valve to the closed state and the inlet valve to the open state at the time of the first selection. A possible maintenance preparation control means and, at the time of the second selection, the inlet valve is closed and the outlet valve is switched to the open state, and each ink is held from the ink pressurization holding means. Provided a maintenance execution control means for controlling can supply pressurized ink to a click-jet nozzle,
An ink jet printer formed so that maintenance can be performed on all ink jet nozzles simultaneously while supplying pressurized ink to the nozzle head by using an elastic restoring action of a member constituting an ink pressure holding unit.

In this invention, for example, at the time of the first selection after the printing operation in which both the inlet valve and the outlet valve are opened is completed, for example, a maintenance command is automatically (or manually) issued. Then, the maintenance preparation control means switches the outlet valve to the closed state and simultaneously (or thereafter) switches the inlet valve to the open state. If the inlet valve is in the open state in advance, the switching can be omitted.

Subsequently, the ink supply pump is supplied and driven. Thus, pressurized ink can be stored in the ink pressurizing and holding means. During this storage period, some of the constituent members are elastically deformed in a direction of increasing the internal volume, so that a large amount of pressurized ink can be stored.

At the time of the second selection thereafter, the maintenance execution control means controls the switching of the inlet valve to the closed state and controls the switching of the outlet valve to the open state simultaneously or thereafter. Then, the component elastically deformed in the expansion direction is elastically restored in the direction to reduce the internal volume. That is,
The pressurized ink can be simultaneously supplied from the ink pressurizing and holding means to the respective ink jet nozzles simultaneously and through the outlet valve by using the elastic restoring force of the member. Therefore, even if the amount of the ink supplied under pressure is small, foreign substances, air, and the like can be quickly and reliably discharged from the inside of each inkjet nozzle of the nozzle head. It is preferable that the supply of the ink supply pump is stopped immediately before the switching.

However, since it is not necessary to increase the capacity of the ink supply pump, downsizing and cost reduction can be achieved, and maintenance of the ink jet nozzle can be performed quickly and reliably while reducing ink consumption. Handling is extremely simple, and long-term smooth maintenance can be guaranteed.

When the ink supply pump is constituted by a pump with an on-off valve function, the pump may be used to form an inlet valve to be switched between the first selection and the second selection. it can.

According to a second aspect of the present invention, there is provided an ink jet printer comprising a printing operation start preparation control means capable of returning the inlet valve to an open state and switching the same between after completion of maintenance and before starting the next printing operation. It is.

In this invention, the printing operation start preparation control means returns the inlet valve closed at the time of maintenance to the open state after the maintenance is completed and before the next printing operation starts. Therefore, in addition to providing the same operation and effect as the case of the first aspect of the present invention, full automation for automatically switching between the printing operation and the maintenance operation can be achieved, so that the handling is further easier.

According to a third aspect of the present invention, the ink pressurizing and holding means is mounted on the hollow main body connected to the inlet valve and the outlet valve at a position other than the opening, and the opening is sealable. And an elastic sheet member.

In this invention, during the maintenance preparation,
Ink flows into the hollow body from the inlet valve. The elastic sheet member made of, for example, metal, rubber, synthetic resin, or the like attached to the opening is elastically deformed in a direction in which the internal volume of the hollow main body is increased by the pressure of the supplied ink. Therefore, a large amount of pressurized ink can be held. During the maintenance operation, the elastic sheet member elastically restores in a direction to reduce the internal volume of the hollow main body, so that the pressurized ink can be rapidly supplied from the outlet valve to the nozzle head.

Therefore, in addition to providing the same functions and effects as in the first and second aspects of the present invention, since the structure is simpler, the life is longer and the cost can be further reduced.

The invention according to claim 4 is an ink jet printer wherein the elastic sheet member is made of synthetic resin.

According to this aspect of the invention, the elastic sheet member can be manufactured from a synthetic resin such as polycarbonate. Therefore, in addition to achieving the same operation and effect as the case of the invention of claim 3, it is possible to further reduce the cost without affecting the quality of the ink.

Further, according to a fifth aspect of the present invention, there is provided an ink jet apparatus wherein the hollow main body has a conical shape or a polygonal pyramid shape having a large sectional area on the opening side and a small sectional area on the connection part side of the outlet valve. It is a printer.

In this invention, the hollow body has a large cross-sectional area on the opening side where the elastic sheet member is mounted, so that the pressure holding amount of ink can be increased, and the hollow body has a small cross-sectional area on the connection side of the outlet valve. Speed can be increased. Therefore, in addition to providing the same operation and effect as the inventions of the third and fourth aspects, the ink outflow speed can be further increased and stabilized. Even if the thickness (weight) of the hollow body is reduced, its strength can be increased.

Further, the invention of claim 6 is an ink jet printer in which the outlet valve is connected to a portion of the hollow main body having the smallest sectional area.

[0030] In this invention, since the throttling effect is large, the ink outflow speed from the outlet valve can be maximized, so that the same operation and effect as the case of the invention of claim 5 can be obtained, and further, the maintenance effect can be obtained. Can be further improved.

[0031]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) The basic configuration of this ink jet printer is the same as that of the previously proposed ink jet printer (FIG. 6).
As shown in the figure, the pressure of the ink supplied from the ink supply pump 32 can be pressurized and held in the middle of the ink supply pipe 31 (31U, 31D) by utilizing the elastic deformation of the constituent member (57). An ink pressure holding means 50, an inlet valve 61 and an outlet valve 65 on the upstream side of the ink pressure holding means 50, a maintenance preparation control means (70) which operates at the time of the first selection, and a second A maintenance execution control means (70) which operates at the time of selection is provided, and while the pressurized ink is supplied to the nozzle head 20 by impact using the elastic restoring action of the member (57) constituting the ink pressure holding means 50, The inkjet nozzles are formed so that they can be maintained all at once.

The same components as those of the previously proposed ink jet printer shown in FIG. 6 are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

In FIG. 1, the nozzle head 20 has nozzle units (20C, 20Y, 20M, 20B) for each color (C, Y, M, B) having a number of ink jet nozzles 27 connected to the ink pressure chambers 26. Formed from
It can reciprocate, for example, by 1/75 inch in the row direction of a print medium (not shown).

Each of the color nozzle units (20C, 20Y, 20M, 20B) forming the nozzle head 20 is supplied with an ink for each color via the ink supply pipe (31) and the ink return pipe (33). The tank 40 is connected. A cassette (ink bottle) 41 for replenishing the respective color inks is detachable from each ink tank 40. Reference numeral 42 denotes a vent pipe.

Each color ink supply tube is formed from an ink supply tube 31 made of a synthetic resin having flexibility. Similarly, each ink return tube is also formed of a flexible synthetic resin ink return tube 33. The ink supply tube 31 is provided with a push-type ink supply pump 32, and the ink return tube 33 is provided with a pull-type ink return pump 34.

The ink supply pump 32 (ink return pump 34) is formed of a roller pump having a plurality (for example, four) of pressing rollers 32R (34R) arranged at predetermined intervals on a circular locus.

These pumps 32 (34) supply ink in the same manner as when the tube 31 (33) is closed with an on-off valve while the pressing roller 32R (34R) is pressed against the tube 31 (33). Return) can be blocked. In addition, ink can be supplied (returned) by rotating the pressing roller 32R (34R) in the cutoff state (pressing state). Further, the pressing roller 3
In a state where the 2R (34R) is separated from the tube 31 (33), the free flow of ink in the tube 31 (33) can be permitted as if the on-off valve were opened.

That is, it is understood that the ink supply pump 32 and the ink return pump 34 are pumps having an on-off valve function.

Therefore, by driving both pumps (32, 34) simultaneously, ink can be circulated between the ink tank 40 and the nozzle head 20 (for example, the nozzle unit 20C). By driving only the pump 32, ink can be supplied to the nozzle head 20 (20C).

Further, if the pump 32 (32R) is kept open and separated and the pump 34 (34R) is closed and pressed, the nozzle head 20 (20
The ink can be supplied from the ink tank 40 through the ink supply tube 31 by using the negative pressure generated by the ink jet operation of C).

In FIG. 2, the ink pressure holding means 50
Is provided in the middle of the ink supply pipe 31 (that is, the upstream pipe 31U and the downstream pipe 31D, which are numbered for convenience), and uses an elastic deformation of the component (57) to supply the ink supply pump. This is means for pressurizing and holding the pressure of the ink supplied from 32.

That is, the maximum value of the ink pressure supplied to the nozzle head 20 (for example, 20C) at the time of the maintenance operation is determined by the discharge pressure of the ink supply pump 32. In the roller pump (32) having the
A large amount of ink cannot be ejected and supplied in Sec). In other words, the ink supply pump 32 that is not always driven
Is constructed so that a large amount of ink can be ejected and supplied only for maintenance, it becomes very large and expensive.

Therefore, an ink pressurizing and holding means 50 is provided so as to be able to store a large amount of ink while maintaining the pressure of the ink supplied from the ink supply pump 32 and to be able to release (flow out) instantaneously.

The ink pressure holding means 50 is provided in the opening 5
The hollow body 51 is connected to the inlet valve 61 and the outlet valve 65 at positions other than 6H, and the elastic sheet member 57 mounted on the hollow body 51 so as to seal the opening 56H. The structure is very simple.

The hollow main body 51 has a conical shape (a polygonal pyramid shape) in which the cross-sectional area gradually decreases from the lower side to the upper side in FIG. 2, and the mechanical strength is increased while reducing the weight. . Functionally, the ink outflow impact at the time of maintenance is increased and the elastic sheet member 57 shown in FIG.
Can be extended while reducing the amount of displacement in the C and D directions.

The elastic sheet member 57 which seals the opening 56 of the hollow main body 51 is a member constituting a part of the ink pressurizing and holding means 50, and is capable of increasing / decreasing (enlarging / reducing) the internal volume of the ink storage chamber 55. is there. The material can be appropriately selected from metals, rubbers, synthetic resins, and the like. In this embodiment, the material is made of synthetic resin (polycarbonate) which is inert, does not affect the ink quality, and is low in cost. It is formed.

The elastic sheet member 57 may be formed integrally with the hollow main body 51.
In order to facilitate replacement of only the elastic sheet member 57, the elastic sheet member 57 is detachably formed on the flange portion 56 of the hollow main body 51.

The outlet valve 65 is connected to the portion (connection portion 54) of the hollow body 51 having the smallest sectional area, and the inlet valve 61
Is connected to a connection portion 53 below the connection portion.

Here, the drive control unit 70 includes a CPU, an RO,
The inkjet printer includes an M, a RAM, and the like, and is formed so as to be able to drive and control the entire inkjet printer. In this embodiment, a maintenance preparation control unit, a maintenance execution control unit, and a printing operation start preparation control unit are formed. I have.

Therefore, each of the drivers 32D, 61D,
The drive (open / close) of the ink supply pump 32, the inlet valve 61, and the outlet valve 65 can be controlled via 65D.

More specifically, the maintenance preparation control means (7
0) indicates that at the time of the first selection, the outlet valve 65 provided on the ink supply pipe 31D on the downstream side of the ink pressurizing and holding means 50 is closed, and the inlet valve 61 provided on the ink supply pipe 31U on the upstream side. Can be switched to the open state, and the ink supply pump 32 is supplied and driven.

Also, maintenance execution control means (70)
Switches the inlet valve 61 to the closed state and the outlet valve 65 to the open state at the time of the second selection so that the ink pressure holding means 50
Is controlled so that pressurized ink can be supplied to each of the inkjet nozzles 20. That is, the ink jet nozzles can be simultaneously maintained while the pressurized ink is supplied to the nozzle head 20 by using the elastic restoring action of the member 57 constituting the ink pressurizing and holding means 50.

Further, the printing operation start preparation control means (70) provided for fully automatic operation switches the inlet valve 61 back to the open state and switches between after the maintenance is completed and before the next printing operation is started. Can be.

Since the ink supply pump 32 is constituted by a pump having an on-off valve function, when the length of the ink supply pipe 31 is short and the rigidity is large, the pump 32
, The inlet valve 61 to be switched at the time of the first selection and at the time of the second selection can be formed. In other words, the inlet valve 61 can always be kept open except for the case of inspection or the like, and the ink supply pump 32 can be formed so as to perform open / close switching control. Even when formed in this way,
The present invention is adapted.

In the ink jet printer according to the first embodiment, for example, at the time of the first selection after the printing operation in which both the inlet valve 61 and the outlet valve 65 are open, the maintenance is automatically or manually performed. When the command is issued, the maintenance preparation control means (70)
Switches the outlet valve 65 to the closed state and simultaneously (or thereafter) switches the inlet valve 61 to the open state. When the inlet valve 61 is in the open state in advance, the switching can be omitted. Thereafter, the ink supply pump 32 is supplied and driven.

Thus, the ink pressure holding means 50 (5
5) can store the pressurized ink flowing from the direction A in FIG. During this storage period, the constituent member (elastic sheet member 57) elastically deforms in the C direction to increase the internal volume, so that a large amount of pressurized ink can be stored.

At the time of the second selection thereafter, the maintenance execution control means (70) controls the switching of the inlet valve 61 to the closed state, and simultaneously (or thereafter) with the outlet valve 6.
5 is switched to the open state and controlled. Then, the component (57) elastically deformed in the expansion (C) direction is elastically restored in the D direction, which reduces the internal volume of the ink storage chamber 55.

That is, from the ink pressure holding means 50,
Utilizing the elastic restoring force of the member (57) and the outlet valve 65
In the direction B, and the pressurized ink can be supplied to each inkjet nozzle 20 all at once and in an impact manner.

Therefore, even if the amount of the ink supplied under pressure is small, foreign matters, air, and the like can be rapidly and reliably discharged from each ink jet nozzle of the nozzle head 20 to the outside. In addition, immediately before the switching, the supply of the ink supply pump 32 is stopped.

However, since it is not necessary to increase the capacity of the ink supply pump 32, the size and cost can be reduced, and the maintenance of the ink jet nozzles can be performed quickly and reliably while reducing the ink consumption. Handling is extremely simple, and long-term smooth maintenance can be guaranteed.

Further, since the cross-sectional area on the side of the opening 56H where the elastic sheet member 57 is mounted is large, the amount of pressurized ink that can be held can be increased. Impact). That is, the ink outflow speed can be made fast and stable. Even if the thickness (weight) of the hollow main body 51 is reduced, its strength can be increased.

Further, since the hollow body 51 is formed in a conical shape and the outlet valve 65 is connected to the portion (54) having the smallest sectional area, the throttle effect is large and the ink outflow speed (impact) from the outlet valve 65 is large. ) Can be maximized, so that the maintenance effect can be further improved.

Then, between the end of the maintenance and the start of the next printing operation, the printing operation start preparation control means (7)
0) returns the inlet valve 61 closed at the time of maintenance to the open state and switches it. Therefore, full automation for automatically switching between the printing operation and the maintenance operation can be achieved, and the handling is much easier.

(Second Embodiment) This embodiment is similar to FIG.
And in FIG. That is, the basic configuration and functions of the second embodiment are the same as those of the first embodiment (FIGS. 1 and 2), but the structure of the elastic sheet member 57 and the position of the connection portion 53 are changed. It is.

In FIG. 3, a connecting portion 53 for connecting the inlet valve 61 has a distal end (lower end) at the elastic sheet member 5.
It is attached in a state where it is pushed deep into the 7 side. Therefore, the inflow ink can be stirred and circulated in the ink storage chamber 55, so that uniformity of the ink properties can be ensured.

As shown in FIG. 4, the elastic sheet member 57 is formed in a concentric concavo-convex (bellows) structure.
That is, the effective sectional area of the member 57 is enlarged with respect to the cross-sectional area of the opening 56H. Therefore, when the contained ink amount is constant, the amount of vertical displacement of the elastic sheet member 57 in FIG. 3 can be suppressed small, and the rigidity can be increased, so that the ink outflow impact can be instantaneously increased.

[0068]

According to the first aspect of the present invention, it is possible to pressurize and hold the pressure of the ink supplied from the ink supply pump by using the elastic deformation of the constituent members interposed in the ink supply pipe. A maintenance preparation control means capable of switching the outlet valve to the closed state and the inlet valve to the open state at the time of the first selection, and capable of driving the supply of the ink supply pump at the time of the first selection; A maintenance execution control means for switching the inlet valve to the closed state and the outlet valve to the open state to control supply of the pressurized ink from the ink pressurizing and holding means to each of the ink jet nozzles; An ink jet preform that can maintain all of the ink jet nozzles simultaneously while supplying pressurized ink to the nozzle head by using the elastic restoring effect of the members Since a data, since the ink supply pump does not need to be large downsizing and cost reduction, and enables quickly and reliable maintenance of the ink jet nozzle while reducing the ink consumption. Handling is extremely simple, and long-term smooth maintenance can be guaranteed.

According to the second aspect of the present invention, the printing operation start preparation control means capable of returning the inlet valve to the open state and switching the state after the maintenance is completed and before the start of the next printing operation is provided. In addition to the effects similar to those of the first aspect of the invention, the automatic operation for automatically switching between the printing operation and the maintenance operation can be achieved, so that the handling is further facilitated.

According to the third aspect of the present invention, the ink pressurizing and holding means is mounted on the hollow main body connected to the inlet valve and the outlet valve at a position other than the opening, and the opening can be sealed. Since the elastic sheet member is formed from the elastic sheet member, the same effects as those of the first and second aspects of the invention can be obtained. In addition, since the structure is simple, the life is long and the cost is further reduced. it can.

According to the fourth aspect of the invention, since the elastic sheet member is made of a synthetic resin, the same effect as that of the third aspect of the invention can be obtained, and further, the quality of the ink is affected. And the cost can be further reduced.

Further, according to the fifth aspect of the present invention, since the hollow body has a large cross-sectional area on the opening side and a small cross-sectional area on the connection side of the outlet valve, it has a conical or polygonal pyramid shape. In addition to achieving the same effects as in the inventions of the third and fourth aspects, the ink outflow speed can be further increased and stabilized. Even if the thickness (weight) of the hollow body is reduced, its strength can be increased.

Further, according to the invention of claim 6, since the outlet valve is connected to the portion having the smallest sectional area of the hollow main body, the same effect as that of the invention of claim 5 can be obtained. In addition to being able to do so, the maintenance effect can be further improved.

[Brief description of the drawings]

FIG. 1 is a system diagram for explaining a first embodiment of the present invention.

FIG. 2 is a diagram for explaining an ink pressure holding unit and the like.

FIG. 3 is a side sectional view illustrating an ink pressure holding unit according to a second embodiment of the present invention.

FIG. 4 is also a bottom view.

FIG. 5 is a view for explaining a conventional serial type ink jet printer.

FIG. 6 is a diagram for explaining a previously proposed inkjet printer.

[Explanation of symbols]

Reference Signs 20 Nozzle head 20C, 20Y, 20M, 20B Nozzle unit for each color 27 Inkjet nozzle 31 Ink supply tube (ink supply tube) 32 Ink supply pump 40 Ink tank 41 Ink cassette 50 Ink pressure holding means 51 Hollow main body 52 Conical shape 53 Inlet valve connection part 54 Outlet valve connection part 55 Ink storage chamber 56 Flange part 56H Opening part 57 Elastic sheet member (constituent member) 61 Inlet valve 65 Outlet valve 70 Drive control unit (maintenance preparation control unit, maintenance execution control unit, Printing operation start preparation control means)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuhiro Suzuki 6-78, Minamicho, Mishima-shi, Shizuoka Prefecture Inside the Tec Mishima Plant (72) Inventor Hitoshi Shioki 6-78, Minami-cho, Mishima-shi, Shizuoka Prefecture KU Mishima Plant F-term (reference) 2C056 EA14 EA20 EA23 EA24 EA25 EC18 EC56 KA03 KA04 KB04 KB08 KB16

Claims (6)

[Claims] 1. An ink jet printer capable of printing while supplying ink from an ink tank to a nozzle head having a plurality of ink jet nozzles through an ink supply pipe, wherein an elastic deformation of a constituent member interposed in the ink supply pipe is performed. An ink pressure holding means capable of holding the pressure of the ink supplied from the ink supply pump under pressure, an inlet valve provided in the ink supply pipe on the upstream side of the ink pressure holding means, An outlet valve provided in the ink supply pipe on the downstream side thereof, and maintenance preparation control capable of switching the outlet valve to the closed state and the inlet valve to the open state at the time of the first selection, and supplying and driving the ink supply pump. Means for switching the inlet valve to the closed state and the outlet valve to the open state at the time of the second selection so that each of the ink jet nozzles is And a maintenance execution control means for controlling the supply of pressurized ink to the nozzle head using the elastic restoring action of a member constituting the ink pressurizing and holding means. An inkjet printer that is designed to maintain the inkjet nozzles all at once. 2. The ink jet printer according to claim 1, further comprising a printing operation start preparation control means capable of returning the inlet valve to the open state and switching the state after the maintenance is completed and before the next printing operation starts. 3. The ink pressurizing and holding means comprises a hollow body connected to the inlet valve and the outlet valve at a position other than the opening, and an elastic sheet member mounted on the hollow body so as to seal the opening. 3. The ink jet printer according to claim 1, wherein the ink jet printer is formed. 4. The ink jet printer according to claim 3, wherein said elastic sheet member is made of synthetic resin. 5. The hollow body has a conical shape or a polygonal pyramid shape having a large cross-sectional area on the opening side and a small cross-sectional area on a connecting portion side of the outlet valve. Inkjet printer. 6. The ink jet printer according to claim 5, wherein the outlet valve is connected to a portion of the hollow body having the smallest sectional area.