JPH03234540A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To prevent an ink in an ink tank from evaporating during a non- recording time and to prevent the deterioration of a recording quality even if a cartridge is left to stand for a long time by providing a means for closing an air hole of the ink tank in relation to a home position. CONSTITUTION:A means for closing an air hole 109 is provided in relation to a home position. Namely, in this constriction, when a carriage 111 is led to the home position, the air hole closing means covers and closes the air hole 109. In this manner, even if a cartridge is left to stand in an unused state for a long term, an ink can be prevented from evaporating from an ink tank. The change of the ink in composition ratio can be prevented, whereby the cartridge has a longer life per se, and a high quality recording can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording apparatus that has a removably replaceable cartridge in which an ink tank is integrated with an inkjet recording head.

[Prior Art J] Conventionally, inkjet recording devices have generally been of a type in which ink cartridges containing a predetermined amount of ink are replaced and ink is replenished; however, when the cost of the inkjet recording head itself is low, An integrated head and ink cartridge system is used, which integrates a predetermined amount of ink and a head. In such a printing apparatus, by integrating the ink and the head, the printing head can be reliably and automatically updated every predetermined printing amount, so that it is possible to always maintain good printing quality.

Additionally, in the unlikely event that a problem occurs that degrades printing quality, the inkjet printing head itself, which is the core part, can be easily replaced, reducing downtime of the printing device.
It is possible to do so. Furthermore, there is the advantage that the danger of foreign matter contamination that occurs during ink replenishment can be avoided.

Incidentally, in such a head/ink tank type cartridge, an atmosphere communication port is provided in the tank wall to communicate with the atmosphere, so that even if the ink in the tank decreases due to being ejected from the recording head, the air flow will be reduced accordingly. Air circulates within the tank, and the pressure within the tank does not change even if the volume of ink changes due to environmental temperature or the like.

[Problems to be Solved by the Invention] However, in the above-described inkjet recording apparatus, if the cartridge is left unused for a long period of time, the ink inside the cartridge evaporates from the atmosphere communication port.

In other words, the main components of water-based ink, which is advantageous from the standpoint of safety, are water, dye, and non-volatile solvent. If the ink evaporates in the tank inside the cartridge, the composition ratio of the ink will change, which may cause clogging in the ejection part of the head, as well as the fixability of the ink to the recording material and the reflection density (OD). There were problems such as the impact on

An object of the present invention is to focus on the above-mentioned conventional problems and to solve them (also when the cartridge is left attached, such as when not recording).

By suppressing ink evaporation and maintaining a stable composition ratio of ink, good quality recording characteristics can be obtained, and
An object of the present invention is to provide an inkjet recording device that contributes to reducing running costs by making ink last longer.

[Means to solve the problem]

In order to achieve this object, the present invention stores ink to be supplied to the ink ejection section, and an ink tank equipped with a vent communicating with the atmosphere and the ink ejection section are integrally mounted on a carriage. The inkjet recording apparatus is configured such that the carriage is guided to a home position during recording, characterized in that means for closing the vent hole is provided in association with the home position.

[For production]

According to the present invention, the first vent closing means is configured to cover and close the vent when the carriage is guided to the home position, so that the cartridge is not left unused for a long time. By preventing ink from evaporating from within the ink tank and suppressing changes in the ink composition ratio, the life of the cartridge itself can be extended and contributes to high-quality recording. do.

[Examples] Examples of the present invention will be described below in detail and specifically based on the drawings.

1A and 1B show an example of a head/ink tank integrated cartridge mounted on the carriage of the inkjet recording apparatus of the present invention. In these figures, 10
0 is the recording head unit of the cartridge 101, 102
Reference numeral 103 refers to the ejection section, which is composed of members related to the ink ejection function of the recording head unit 101, and 103 refers to the ejection section 1.
This is a supply tank section that supplies ink to 02. Discharge part 1
02 is a plurality of discharge ports 10 arranged on the discharge surface 104.
4A, a liquid path (not shown) for guiding ink to each ejection port 104A, an ejection energy generating element such as an electrothermal converter disposed in the liquid path, and a supply liquid chamber communicating with each liquid path.

Further, 105 is an ink tank incorporated in the cartridge 101, 10G is a lid member thereof, and 107 is an ink tank 1.
The ink absorber 107 is an ink absorber loaded in the ink absorber 05, and the ink absorber 107 is formed of a porous material or fiber, and is impregnated with ink. Furthermore, the ink tank 105 has a hollow chamber 1 along one side edge of the ink absorber 107.
08 is formed, and a vent 109 is provided as an atmosphere communication port between this hollow chamber 10g and the outside.

FIG. 2A shows an embodiment of an inkjet recording apparatus equipped with such a head/ink tank integrated cartridge, that is, a disposable cartridge 101.
1 is a carriage carrying a cartridge 101; 112;
113 is a holding member for fixing the cartridge 101 in a positioned state on the carriage 111; 113 is connected to a connector (not shown) on the carriage Ill;
This is a flexible cable that supplies ejection signals to the printer according to recorded data. Note that the positioning of the cartridge 101 with respect to the carriage 111 can be done, for example, by inserting a locking hole provided in the cartridge 101 into the carriage 1, although this is not shown.
This is carried out by engaging the locking protrusion on the 11 side.

In this way, the carriage 111 carrying the cartridge 101 is moved along the guide shaft 114 by a driving means (not shown), and during the movement, the carriage 111 is placed on a recording material (hereinafter referred to as a recording sheet) 116 held by a platen 115. Ink is ejected from the ejection opening 104A of the ejection unit 102 to perform recording. Note that 120 indicates the ejection surface 10 when the ejection section 102 of the recording head unit 100 is moved near the home position on the left in FIG. 2A during non-recording.
4, the cap member 122 performs a recovery operation by suctioning ink from the ejection port 104A with the suction pump 121.
This is the tube that connects the two. Furthermore, 130 is an elastic closure member made of rubber or the like, 131 is a holding member thereof, and as shown in FIG. 2B, a cap member 1 is attached to the discharge part.
20, the closing member 130 comes into contact with the vent 109 of the cartridge 101 and closes it.

Although the vent 109 was left closed for a long time using such a closing member 130 in the state shown in FIG. 2B, the amount of ink evaporated was lower than when the vent 109 was left open. It becomes less than l/10.

No problematic changes were observed in the composition ratio of the ink. Furthermore, in this state, when a suction operation was performed using the suction pump, the inside of the ink tank 105 became negative pressure, making suction impossible, or the meniscus was destroyed and air was mixed into the discharge section 102. There was nothing to do.

However, in this case, in order to perform normal suction, it is necessary to satisfy the following conditions between the air volume V in the ink tank and the suction amount Vo.

However, here, PTH: critical pressure difference from atmospheric pressure required to maintain meniscus (atm) On the other hand, in the above example, Pro = 0.03a
ts+, and the suction amount by the pump 121 is V! 0.0
Since the air volume is 5 cc, the air capacity V should be about 1.7 cc, but in reality, it was set to 3 cc in consideration of safety.

Next, the results of experiments conducted using the configuration of Example 1 described above will be explained.

The ink used had a composition ratio of 3% dye, 77% water, 15% diethylene glycol, a nonvolatile solvent, and 5% ethanol, a volatile solvent. Further, the ink capacity in the ink tank 105 in the cartridge 101 was set to 30 cc.

Then, after completing this condition (using two types of inkjet cartridges made the same), an elastic closing member 130 was obtained from the inkjet recording device of the present invention and the device of the present invention.
The cartridges were left in the devices except for one month and three months under the environmental conditions of 30° C. and 20% humidity.

After the cartridges were left to stand, the composition ratio of the ink in each cartridge was examined, and then printing was performed to check various performances.

The following results are shown in Tables 1 and 2.

As can be seen from these results, in this example, there was almost no evaporation of the ink (and no change in the composition ratio).

Also, as a matter of course, the results of comparative tests conducted under various conditions before being left were almost unchanged and good.

Note 1: Here, the reflection density is measured using a Macbeth reflection densitometer when solid printing is performed on a 1 cm square.

Note 2: Fixability is 1 for a certain type of paper (plain paper).
Solid printing of cm square was performed, and after a predetermined time, using Silbon paper as a transfer paper, a predetermined pressure was applied, and the presence or absence of drag marks after rubbing was judged.

Remark 3: The emissivity is the limit time (seconds) from the start of ejection from each ejection port until the next normal ejection.

Note 4: Stickiness refers to the ink extracted from the cartridge in an environment of 15℃ and 10%, placed in a capillary tube, and left in an oven at 60℃ and 5% until it loses fluidity. time (hrs, ).

Note 5: Print quality is evaluated by recording prints containing various patterns and evaluating the quality at that time.

Note 6: The occurrence rate of ejection failure is determined by checking the occurrence rate by using the above pattern as a - sheet if a slight trace of ejection failure is found in the sheet when printing with the above pattern in a predetermined mode. It is something that

FIG. 3 shows a second embodiment of the present invention. This example is an example in which the cap member 120 is movable almost along the moving direction of the carriage 111, and 123 is constructed integrally with the cap member 120. An engagement member 125 serves to move the cap member 120 along the guide groove 124A of the guide member 124 by coming into contact with the carriage 111 when the carriage 111 moves to the left from the position shown in the figure, and 125 is for returning the cap member. The spring 126 is the discharge surface 10 of the discharge section 102.
This is a blade member made of an elastic material or the like that cleans the 4.

Therefore, in this embodiment, the carriage 111 is
According to the movement position after engaging with 23, it can be stopped at the start position, the empty discharge position (which may be the same as the start position), the suction position, and the home position. However, in the suction position and the home position, the cap member 120 is attached to the ink ejection surface 104 of the head due to the shape of the guide groove 124A. Therefore, in this example, there is no need to take into consideration the amount of suction involved in the suction operation and the air volume in the tank as described above.

Thus, only in the home position, the closure member 13
The vent hole 109 is closed by the 0, thereby preventing ink from evaporating.

Next, a third embodiment of the present invention will be described with reference to FIG.

This embodiment is designed to prevent the pressure inside the ink tank 105 from increasing due to changes in the environmental temperature during storage, thereby preventing ink from leaking. In FIG. 4, 140 is a cylindrical An elastic closure contact member (hereinafter referred to as a cylindrical member), 142 is connected to the cylindrical member 140, has an opening to the atmosphere at the other end, and is held in a U-shape; A non-volatile liquid, such as silicone oil, is injected into the U-shaped tube member 142. Here, the tube member 142 is preferably made of a fluorine-based material such as Teflon (trade name) or a metal material that has low gas permeability.

In the ink evaporation prevention device configured as described above, the ink ejection surface 104 of the cartridge 101 is capped by the cap member 120, and at the same time, the peripheral surface of the tip of the cylindrical member held by the holding member 131 is closed around the vent hole 109. press against. Furthermore, since the silicone oil 143 is retained at the bottom of the U-shape in the tube member 142, the inside of the ink tank 105 can be isolated from the outside air, thereby preventing ink from evaporating. Furthermore, during suction, the silicone oil 143 moves toward the ink tank by an amount corresponding to the negative pressure depending on the pressure fluctuation inside the ink tank 105, but by making the pipe length shown by 21 in the figure sufficiently long, The silicone oil 143 is not drawn into the tank. Thus, when the suction operation is completed and the ink cartridge 101 is released from the cap member 120, the silicone oil 143 returns to its original stable state.

Furthermore, by keeping the length of the tube indicated by 122 sufficiently long, the ink tank 105 can be
Even if the air inside expands, the expansion will be absorbed by the ρ of the pipe member.
Since the ink can be absorbed in two parts, the silicone oil 143 will not leak to the outside, and it is only necessary to move the silicone oil 143 to the ink tank 105 side even in a low temperature atmosphere. In this way, ink will not leak outside or damage the meniscus even when environmental temperature changes or suction operations occur, and the inside of the ink tank can be isolated from the outside air, thereby suppressing ink evaporation. I can do it.

FIG. 5 shows another form of the third embodiment. In this example, instead of retaining the nonvolatile liquid in the pipe member 142, a liquid storage tank 145 is provided, and the opening 142A of the pipe member 142 is immersed in this storage tank 145. This figure shows a state in which the cartridge 101 is capped by a cap member (not shown).The other configuration is the same as that shown in FIG. 4, and the operation is also the same as described above. Omitted.

FIG. 6 shows a fourth embodiment of the invention. In this example, vent 1
A bellows-shaped stretchable film 152 made of a thin rubber film or the like is attached to a holding member 151 that holds a cylindrical member 150 for closing the bellows chamber 150, and the volume V inside the bellows chamber 153 is It is designed to change freely depending on the pressure inside the tank. In the vent closing means configured as described above, the volume of the bellows chamber 153 is maintained at V even when the vent port 109 of the cartridge 101 is not in contact with the vent port 109 and the pressure inside the tank is not changed even when the vent port 109 of the cartridge 101 is closed. However, when the pressure inside the tank changes due to changes in environmental temperature, etc., the elastic membrane 152
expands and contracts freely to increase and decrease the indoor volume V.

The relationship between the change in tank internal pressure ΔP and the change in volume ΔV at this time is shown in FIG. However, ΔP in this case must always be within a range in which the meniscus formed at the position of the ink discharge 0104A is maintained. It would be a good idea to make it possible. Note that the stretchable membrane 152 can be made of vinyl or the like, but in this case it is preferably made of an elastic material because it does not have its own restoring force.

FIG. 8 shows a vent closing member 160 in which the cylindrical member, holding member, and elastic membrane shown in FIG. 7 are integrated with an elastic material such as rubber.
It was formed as follows. By configuring in this way, it is possible to further simplify and downsize the device, thereby reducing costs.

FIG. 9 shows a fifth embodiment of the present invention. This example shows an example in which the cartridge 101 itself has the function of opening and closing its vent port 109. Here, 170 is the support shaft 171
In this example, it is provided on the top surface of the cartridge 101, and the ventilation hole 109 provided on the top surface of the cartridge 101 is moved in the direction of the arrow of the carriage 111. It can be opened and closed according to the movement.

That is, there is a ventilation hole 10 at the end of one arm 170A.
An elastic stopper 130A is provided to close the cap member 9, and a two-pronged arm 170B is formed on the other end. Then, one side of the arm 170B engages with an engagement pin 172 fixed to the recording apparatus main body side, thereby rotating the movable closing member 170 to the position shown by the broken line. At the home position, the end of the arm 170A is rotated. The vent 109 is closed by the plug 130A.

Note that the support shaft 171 and the bearing portion 17 of the movable closing member 170
0c are formed with spiral thread grooves, and as the arm 17OA rotates clockwise, the arm 170A is pulled down toward the top surface of the ink tank and presses the vent 109 from above. It's Nishide. Although not shown in the drawings, for example, a part of the arm 17OA may be configured to be elastically locked to a locking portion provided on the top surface of the ink tank when the vent port 109 is closed by the movable closing member 170. is preferable, and by doing so, it is possible to prevent ink from evaporating even when the cartridge 101 is removed from the carriage 111. Furthermore, when the carriage 111 is moved from the home position in the direction of arrow B, the engagement pin 172 engages with the other arm 170B, causing the movable closing member 170 to rotate in the counterclockwise direction. Keep the vent 109 open.

In this embodiment, the vent 109 and the movable closing member 170 are provided on the top surface of the ink tank, but the installation position and configuration of these are not limited to this.In short, the vent 109 is closed at the home position, Any configuration may be used as long as it is configured to open the vent 109 when the recording operation is started from the home position.

Furthermore, instead of the closure plug, it is also possible to provide a vent closure member of the form shown in FIGS. 6 and 8, for example.

It should be noted that the present invention provides excellent effects particularly in bubble jet recording heads and recording apparatuses among ink jet recording systems.

This is because such a system can achieve higher recording density and higher definition, and it is expected that the fixing speed will be even slower depending on the recording pattern.

As for typical configurations and principles thereof, it is preferable to use the basic principles disclosed in, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740,796. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, it is necessary to arrange the liquid (ink) in accordance with the sheet and liquid path that hold it. The electrothermal converter that is
By applying at least one drive signal that corresponds to the recording information and provides a rapid temperature rise exceeding nucleate boiling, the electrothermal transducer generates thermal energy to cause film boiling on the thermally active surface of the recording head. This is effective because bubbles can be formed in the liquid (ink) in one-to-one correspondence with this drive signal. The growth and contraction of this bubble causes the liquid (ink) to be ejected through the ejection opening to form a small droplet (at least one droplet).If this drive signal is in the form of a pulse, the growth and contraction of the bubble will occur immediately and appropriately. Because you will be exposed to
Particularly responsive liquid (ink) ejection can be achieved,
More preferable pulse-shaped drive signals include those described in U.S. Pat. Nos. 4,463,359 and 4,345,262.
Those described in the specification are suitable. Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

The configuration of the recording head unit includes a combination configuration of an ejection port, a liquid path, and an electrothermal converter (straight liquid flow path or right-angled liquid flow path) as disclosed in each of the above-mentioned specifications. U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,459 disclose a configuration in which the portion is arranged in a bending region.
A configuration using the specification of No. 600 is also included in the present invention. In addition, JP-A-59-123670 discloses a configuration in which a common slit is used as a discharge part for a plurality of electrothermal converters, and a hole that absorbs pressure waves of thermal energy is disclosed. The effects of the present invention are also effective even with a configuration based on Japanese Patent Application Laid-open No. 138461/1985 which discloses a configuration corresponding to the discharge section. That is, regardless of the form of the recording head, fixing can be performed reliably and efficiently.

In addition, even the serial type shown above can be easily replaced by being attached to the main body of the device, making it possible to electrically connect to the main body of the device and supply ink from the main body as described in this example. The present invention is particularly effective when using a chip-type recording head or a cartridge-type recording head that is integrally provided with the recording head itself.

In addition, regarding the type and number of recording heads installed, for example, in addition to one type that corresponds to single-color ink, there is also a plurality of recording heads that correspond to multiple inks with different recording colors and densities. It may be something that can be done.

[Effects of the Invention] As described above, according to the present invention, since the means for closing the vent of the ink tank is provided in relation to the home position, the ink in the ink tank is prevented from evaporating during non-recording. Even if the ink is left for a long time, the composition of the ink will not change and the recording quality will not deteriorate. In addition, since it is possible to extend the life of the ink, it contributes to reducing running costs, and furthermore,
Since there is no need to provide extra ink tank capacity, it has become possible to provide a small and inexpensive cartridge.

Further, by providing a vent closing means in the cartridge itself, it is possible to prevent ink from evaporating even when the cartridge is removed.

[Brief explanation of drawings]

1A and 1B are perspective views and sectional views showing an example of the structure of a cartridge according to the present invention, and FIGS. 2A and 2B show the structure of the first embodiment of the present invention during a recording operation and in a capping state, respectively. 3 is a configuration diagram of a second embodiment of the present invention, FIG. 4 is a perspective view of a configuration of a third embodiment of the present invention, and FIG. 5 is a perspective view of another form of the third embodiment. The configuration diagram, FIGS. 6 and 8 are explanatory diagrams of the vent closing means according to the fourth embodiment of the present invention, FIG. 7 is a graph showing the relationship between pressure change and volume change in the tank, and FIG. 9 is a graph showing the relationship between pressure change and volume change in the tank. FIG. 7 is an explanatory diagram of a vent closing means according to a fifth embodiment of the present invention. DESCRIPTION OF SYMBOLS 100... Recording head unit, 101... Cartridge, 102... Ink ejection part, 104... Ink ejection surface, 105... Ink tank, 107... Ink tank absorber, 109... Ventilation port, 111... Carriage, 120... Cap member, 121... Suction pump, 130... Closure member, 130A... Occlusion plug, 131.151... Holding member, 140, 150. ... Cylindrical elastic member, 142 ... Pipe member, 143 ... Silicone oil, 153 ... Expandable membrane, 160.170 ... Movable closing member, 170A, 170B ... Arm 172 ... Connection Bin. 7) L-I Luji Φ1 One cum to the meat J” and Chikuri Azai 10 Figure 1A $t41 Bow 1; ``The -fri of the air'' and the letter σh Figure 1B Figure 1B fist almost 73 degrees? 11Φ fraud? 11th view Figure 5 Figure 8 tδ6 Figure

Claims (1)

[Scope of Claims] 1) An ink tank that stores ink to be supplied to an ink discharge section and is equipped with a vent communicating with the atmosphere and the ink discharge section are integrally mounted on a carriage, and the carriage is mounted when not printing. What is claimed is: 1. An inkjet recording apparatus in which the air is guided to a home position, characterized in that means for closing the vent is provided in association with the home position. 2) The inkjet recording apparatus according to claim 1, wherein the means for closing the vent includes means for absorbing pressure changes within the ink tank. 3) A means for closing the vent is provided at the home position, and the vent is closed in response to an operation of guiding the carriage to the home position. inkjet recording device. 4) The means for closing the vent port is provided in the ink tank itself, and the vent port is closed in response to an operation of guiding the carriage to the home position. The inkjet recording device described in . 5) The ink discharge section has an electrothermal conversion element for applying thermal energy that causes film boiling to the ink as energy used for ink discharge. The inkjet recording device according to any one of the items.