JP3175396B2 - Inkjet recording head cartridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head cartridge mounted on an ink jet recording apparatus.

[0002]

2. Description of the Related Art Conventionally, in a recording head used in an ink jet recording apparatus, for example, Japanese Patent Application Laid-Open No. Sho 60-2
As described in Japanese Patent No. 04345 or the like, there is known an apparatus in which a recording head unit and an ink storage unit can be detachably mounted. A print head cartridge in which the print head unit and the ink storage unit can be removably mounted is compared with a print head cartridge in which the print head unit and the ink storage unit are integrated. Only one of them needs to be replaced, and the running cost is low.

On the other hand, in a recording head cartridge used in an ink jet recording apparatus, ink is supplied from an ink storage section to a recording head, and recording is performed by discharging ink from the recording head onto a recording medium. At this time, the recording head receives the supply of ink from the ink storage unit due to the negative pressure generated when the ink is ejected. However, simply connecting the recording head and the ink storage unit cannot supply ink stably due to a positional relationship between the ink surface and the recording head, a change in ink pressure due to a change in the remaining amount of ink, and the like. The print quality deteriorates. Therefore, it has been considered to provide a pressure adjusting valve or a negative pressure generating unit between the recording head and the ink storage unit. The pressure regulating valve is apt to fail due to dust and the like, and is not suitable for actual use.

As a technique for providing a negative pressure generating section, for example, as described in Japanese Patent Application No. 3-285745, an ink storage section and a second ink chamber are connected by a capillary tube.
There is a technique for supplying ink so that the pressure in the second ink chamber is always kept constant by dropping the ink from the tip of the capillary into the second ink chamber by the negative pressure in the second ink chamber. In this technique, it is necessary to always keep the capillary filled with ink. However, depending on the storage state of the cartridge, air may enter the capillary tube, and there is a handling problem. Further, it is necessary to integrally form the ink containing portion and the second ink chamber so that air does not enter the capillary tube. In the case where the cartridge portion is configured to be detachable as described above, no replacement is necessary. Second
The ink chambers need to be replaced, which raises running costs and also causes a problem that the replacement parts become large in order to secure a sufficient amount of ink.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and eliminates fluctuations in ink pressure applied to a recording head to improve reliability and reduce costs. It is an object to provide a recording head cartridge.

[0006]

According to the present invention, there is provided an ink jet recording head cartridge used in an ink jet recording apparatus, comprising: a recording head for discharging ink to perform recording; a negative pressure generating section for supplying ink to the recording head; An ink storage unit for storing the ink; and a connection unit connecting the ink storage unit and the negative pressure generation unit, wherein the connection unit has no internal pressure difference between the ink storage unit and the negative pressure generation unit. In such a case, an opening where ink is not dropped due to the surface tension of the ink is provided, and when the internal pressure difference between the ink storage unit and the negative pressure generating unit exceeds the surface tension, the ink extruded from the opening is sent to the negative pressure generating unit. The ink storage section is configured to be detachable, and the ink storage section is replaceable.

[0007] A valve may be provided between the ink containing section and the negative pressure generating section. Further, the recording head unit may be configured to be detachable, and the recording head unit may be replaceable. Further, the negative pressure generating section may be mounted on a carriage of the ink jet recording apparatus.

[0008]

[0009]

According to the present invention, in an ink jet recording head cartridge used in an ink jet recording apparatus,
A recording head that performs recording by discharging ink, a negative pressure generating unit that supplies ink to the recording head, an ink storing unit that stores ink, and a connecting unit that connects the ink storing unit and the negative pressure generating unit An opening in which ink does not drip due to the surface tension of the ink when there is no internal pressure difference between the ink container and the negative pressure generating unit in the connecting unit, and the ink container and the negative pressure When the internal pressure difference of the generating section exceeds the surface tension, the ink extruded from the opening is sent to the negative pressure generating section, so that the ink is always filled like the capillary used in the prior art. There is no portion to keep, and it becomes possible to always supply ink to the recording head stably. Further, since the ink storage section is configured to be detachable and the ink storage section is replaceable, replacement parts can be simplified and running costs can be reduced.

[0010]

[0011]

FIG. 1 is an overall configuration diagram showing one embodiment of an ink jet recording head cartridge of the present invention. In the drawing, 1 is a recording head unit, 2 is an ink storage unit, 3 is a relay unit, 4 is an ink storage unit mounting member, 5 is a recording head unit mounting member, 6 is an ink supply tube, 7 is an ink supply tube insertion port,
8 and 9 are electrical connectors, and 10 is an input / output terminal. The ink jet recording head cartridge is configured by mounting a recording head unit 1 and an ink storage unit 2 on a relay unit 3.

The ink container 2 is filled with ink. The ink storage unit 2 is configured to be detachable from the relay unit 3. When the ink storage unit 2 is mounted on the relay unit 3 by the ink storage unit mounting member 4 provided in the ink storage unit 2, the relay unit 3 is mounted. Fixed so as not to be easily deviated. When the ink container 2 is mounted on the relay unit 3, the ink supply pipe 6 of the relay unit 3 is inserted into the ink container 2. As will be described later, in the ink jet recording head cartridge of the present invention, the ink is supplied from the ink storage section 2 to the negative pressure generating section in the relay section 3 by the internal pressure difference between the two. Therefore, in order to prevent the leakage of the ink, it is necessary to increase the airtightness at the joint. For this purpose, for example, an elastic seal portion is provided at a portion where the ink supply tube 6 is inserted, and the seal portion is pierced by inserting the ink supply tube 6, or a portion where the elastic body can be opened is expanded. Various configurations can be used, such as a configuration in which the cable is inserted by inserting. Further, a valve may be provided at the insertion port of the ink supply pipe 6. This valve can be configured to be movable controllable from the relay unit 3. Also in this case, it is necessary to sufficiently consider the airtightness between the valve and the ink supply pipe 6. In addition, when the valve is provided at the insertion port of the ink supply pipe 6 of the ink storage unit 2, it has an effect of preventing ink leakage when the ink storage unit 2 is removed.

FIG. 2 is a configuration diagram showing an example of the ink storage section 2. In the figure, 11 is a housing, 12 is an air communication port, 13 is an ink bag, 14 is an ink supply valve, and 15 is an ink supply port. The ink bag 13 is filled with ink, and the ink supply valve 14 is normally closed. An air communication port 12 is provided in an upper portion of the housing 11. The ink supply unit 2 is mounted on the relay unit 3, and the ink supply valve 14 is operated in a state where the pressure in the ink supply pipe 6 of the relay unit is negative.
Is opened, the ink in the ink bag 13 is supplied to the ink supply pipe 6 according to the pressure difference between the atmospheric communication port 12 and the atmospheric pressure applied to the ink bag 13.

Returning to FIG. The ink storage unit 2 and the recording head unit 1 are mounted on the relay unit 3. Further, a negative pressure generating section is stored inside the relay section 3, and an ink supply pipe 6 extending from the negative pressure generating section protrudes. Ink is supplied from the ink container 2 to the negative pressure generator via the ink supply pipe 6 when the ink container 2 is mounted. When the recording head unit 1 is mounted on the relay unit 3, an ink supply tube is inserted into the ink supply tube insertion port 7, and ink is supplied to the recording head unit 1 from the negative pressure generating unit inside the relay unit 3. You. The electrical connector 8 outputs a drive control signal to the recording head unit 1. The electrical connector 9 receives a drive control signal of the print head unit 1 from the printing apparatus main body and sends the drive control signal to the electrical connector 8, and also controls an ink amount control solenoid mounted in the relay unit 3 and an ink remaining amount. It is connected to sensors and the like, and inputs and outputs these signals. The relay section 3 is attached and fixed to a carriage or the like of the ink jet recording apparatus.

The recording head unit 1 performs recording by discharging ink from a nozzle arranged inside the recording medium. The recording head unit 1 is configured to be detachable from the relay unit 3, and is fixed to the relay unit 3 by the recording head unit mounting member 5. The recording head 1 is connected to the relay 3
The ink supply pipe provided in the recording head section 1 is inserted into the ink supply pipe insertion port 7 of the relay section 3 and connected to the negative pressure generating section to supply the recording head section 1 with ink. Is done. For example, an O-ring, a SUS mesh filter, or the like can be attached to the ink flow path such as the ink supply pipe. Further, the input / output terminal 10 is connected to the electrical connector 8 of the relay unit 3 when the recording head unit 1 is mounted. The replacement of the recording head unit 1 is performed by counting the number of accumulated driving pulses after the recording head unit 1 is mounted on the relay unit 3 and storing the counted number in, for example, an EEPROM. The replacement of the recording head unit 1 is prompted. The user may perform the exchange based on the exchange instruction.

As described above, according to the ink jet recording head cartridge of the present invention, the recording head unit 1 and the ink storage unit 2 are configured to be detachable from the relay unit 3.
Only the parts that need to be replaced need be replaced according to their life. Therefore, running costs can be reduced. In particular, since the ink storage section 2 can be replaced separately from the negative pressure generating section, the replacement parts can be simplified, the size can be reduced, the cost can be reduced, and the amount of ink that can be stored can be increased. Can be reduced.

FIG. 3 is a cross-sectional view for explaining the structure near the relay section 3 (FIG. 1) in one embodiment of the ink jet recording head cartridge of the present invention. In the figure, FIG.
The same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. 21 is an ink relay member, 22 is an ink holding member housing, 23 is an ink holding member, 24 is an ink remaining amount sensor,
25 is a solenoid, 26 is an ink supply valve opening / closing member, 27
Is a capillary, and 28 is an opening.

The relay section 3 contains an ink relay member 21, an ink remaining amount sensor 24, a solenoid 25, and the like. An ink holding member housing 22 made of polyester resin is formed in the ink relay member 21, and an ink holding member 23 made of polyester felt is built therein, and is impregnated with ink. This ink relay member 2
1 forms a negative pressure generating portion. Ink holding member housing 22
Above is formed a capillary tube 27 and an ink supply tube 6, and the capillary tube 27 is mounted with an optical ink remaining amount sensor 24 composed of a light emitting element and a light receiving element. The ink holding member 23 and the capillary tube 27 hold the ink by the capillary force when the recording head unit 1 is detached from the relay unit 3 so that ink leakage does not occur. An ink supply tube insertion opening 7 is opened beside the ink holding member housing 22.

When the recording head unit 1 is mounted on the relay unit 3, the recording head unit 1 is fixed by the recording head unit mounting member 5, the input / output terminal 10 of the recording head unit 1 is connected to the electric connector 8, and the recording head unit 1 is connected. Of the ink supply pipe penetrates the ink supply pipe insertion port 7 and is pressed against the ink holding member 23. On the other hand, when the ink storage unit 2 is mounted on the relay unit 3,
The ink supply pipe 6 is fixed by the ink container mounting member 4, and is inserted into the ink container 2. At the same time, the solenoid 25 is connected to the ink supply valve 14 of the ink container 2 via the ink supply valve opening / closing member 26.

FIG. 5 is a perspective view showing an example of the ink supply valve 14. In the figure, 28 is an opening. Ink supply valve 1
An opening 28 is provided in the tubular portion below 4.
In a state where the ink storage unit 2 is removed and a state where the ink supply valve is not moved by the solenoid 25, this opening is not exposed to the inside of the ink storage unit 2, for example. By the spread of
The ink in the ink container 2 does not leak. Solenoid 2
5, when the ink supply valve 14 is pushed upward, the opening 28 appears in the ink container 2.
Of course, the ink supply valve 14 may have another mode. For example, a rotating body having a slit may be used in which ink is supplied when the opening provided in the ink supply pipe 6 coincides with the slit. May be exposed.

The operation of one embodiment of the ink jet recording head cartridge of the present invention will be described with reference to FIGS. FIG. 4 shows the ink supply valve 1 in FIG.
4 is a sectional view showing a closed state, and FIG. 6 is an explanatory diagram of ink supply.

When ink is consumed in the recording head unit 1 by printing or suction from nozzles during maintenance, the ink filled in the ink holding member 23 is sent to the recording head 19. As a result, the amount of ink in the ink holding member housing 22 and the ink supply pipe 6 decreases, and the pressure in this portion decreases. Thereafter, the solenoid 25 is turned on for a certain period by the drive signal, and the ink supply valve 14 is opened via the ink supply valve opening / closing member 26.
When the ink supply valve 14 is opened, the ink in the ink container 2 is supplied to the ink holding member 23 via the ink supply pipe 6.
Is dropped. This state will be described with reference to FIG.

The size of the opening 28 provided in the ink supply valve 14 or the ink supply pipe 6 is adjusted by the surface tension of the ink so that it does not drop in a normal state. When the pressure in the ink supply pipe 6 decreases due to the consumption of the ink, the ink supply pipe 6 and the ink container 2
6 (A) to 6 (C), the ink gradually protrudes from the opening 28 according to the pressure difference. Then, when the pressure difference exceeds the surface tension of the ink, FIG.
As shown in (2), it is transmitted to the inside of the ink supply pipe. As the ink is dropped, the pressure in the ink supply pipe 6 increases. Then, the ink supply pipe 6 and the ink storage section 2
When the pressure difference with the surface tension of the ink balances with the surface tension of the ink, the dropping of the ink stops. As described above, since the ink is directly dropped from the ink storage unit 2, the ink is filled in the ink supply pipe 6 as in the related art, and the ink relay member 2 is used.
It is not necessary to replace with the ink container 1, and only the ink container 2 can be replaced.

Although FIG. 6 shows one opening 28, the number of openings 28 is not limited to one, and a plurality of openings 28 can be provided. In that case, ink is dropped into each opening as shown in FIG.

The ink dropped into the ink supply pipe 6 is
The ink is absorbed by the ink holding member 23 through the capillary tube 27 along the tube wall in the ink supply tube 6. With the dropping of the ink, the pressure in the ink supply pipe 6 and the ink holding member accommodating portion 22 approaches the atmospheric pressure, and the dropping of the ink stops. The solenoid 25 is controlled to be ON for a time sufficient to supply ink. Thereafter, the solenoid 25 is turned off and the ink supply valve 14 is closed. This state is shown in FIG. At this point, when the ink remaining amount sensor 24 detects that there is no ink, a signal indicating that there is no ink is output to the recording apparatus, and the user is prompted to replace the ink container 2.

In this example, the control circuit of the main body of the recording apparatus controls the solenoid 25 to be ON for a certain period of time on the assumption that the ink is consumed by performing the suction operation during printing or maintenance. When the amount sensor 24 detects that there is no ink, the solenoid 25 may be turned on to drop ink, and the solenoid 25 may be turned on until the detection of no ink is released. In this case, if the ink-free state is not released even after a certain time has elapsed since the solenoid 25 was turned on, it is determined that there is no ink in the ink storage unit 2 and the user is required to replace the ink storage unit 2. Control to prompt.

FIG. 7 is a sectional view for explaining another structure near the relay section 3 in an embodiment of the ink jet recording head cartridge of the present invention. In the figure, the same parts as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. 29 is a pressure sensor. In FIG. 3, the remaining ink amount is detected by the optical ink remaining amount sensor 24, but a pressure sensor 29 may be used as shown in FIG. When the pressure sensor 29 is used, a decrease in the pressure in the ink supply pipe 6 is detected, and the solenoid 25 is operated to open and close the ink supply valve 14. , It can be configured to detect that there is no change, and to detect that there is no ink. Although FIG. 7 shows a state in which the ink supply valve 14 is opened, when the ink supply valve 14 is closed, a state similar to FIG. 4 is obtained.

FIG. 7 shows a configuration without using the capillary tube 27. In this case, the ink can be held only by the capillary force of the ink holding member 23. The ink holding member 23 is exposed to the air in the ink supply pipe 6,
There is a possibility that air may be trapped by the ink transmitted through the ink supply pipe 6. When this air reaches the recording head unit 1, it causes ink ejection failure and the like,
Image quality decreases. In order not to trap air, the lower end of the ink supply pipe 6 may be immersed in the surface or inside of the ink holding member 23.

In the configuration shown in FIGS. 3 and 7, the ink supply valve 14 is provided at the insertion port of the ink supply pipe 6, but this valve is provided in the middle of the ink supply pipe 6, or between the ink supply pipe 6 and the ink holding pipe. It is also possible to provide at the connecting portion of the member accommodating portion 22. In this case, ink drops into the ink supply pipe due to the relationship between the pressure difference between the ink supply pipe above the ink supply valve 14 and the ink storage section 2 and the surface tension of the ink. Therefore, if the ink supply valve 14 is closed in a well-balanced state, the ink does not drop into the ink supply pipe 6, and the ink drops when the ink supply valve 14 is opened.

In the case where the ink supply valve 14 is not provided at the insertion port of the ink supply pipe 6, a structure for preventing ink from leaking when the ink container 2 is removed is required. For example, it is possible to adopt a configuration in which the tip of the ink supply pipe 6 is sharpened and penetrated through an insertion port formed of an elastic body provided in the ink storage section 2. At this time, an opening may be provided in the tube wall of the ink supply tube 6 protruding into the ink.
The elastic member provided in the ink storage section 2 may be a seal member having no elastic force when the attachment and detachment are not performed a plurality of times.

As another method, the air communication port 12 of the ink storage section 2 is opened and closed in accordance with the attachment and detachment of the ink storage section 2 to and from the relay section 3, and the air communication port 12 is removed with the ink storage section 2 removed. If the cover 12 is closed, the ink does not leak from the insertion port of the ink supply pipe 6.

When the ink supply valve 14 does not control the dropping of ink, the ink supply valve 14 may not be used. In a configuration that does not use the ink supply valve 14, the solenoid 25 and the ink supply valve opening / closing member 26 are also unnecessary. Also in this case, a structure for preventing ink from leaking when the ink containing section 2 is removed is necessary, and the same structure as in the case where the above-described ink supply valve 14 is not provided at the insertion port of the ink supply pipe 6 is necessary. Configurations can be used.

[0033]

As is apparent from the above description, according to the present invention, when there is no internal pressure difference between the ink containing portion and the negative pressure generating portion, the opening where the ink does not drip due to the surface tension of the ink is formed. When the internal pressure difference between the ink storage section and the negative pressure generating section exceeds the surface tension, the ink extruded from the opening is sent to the negative pressure generating section, so that the ink is always discharged like the capillary used in the prior art. There is an effect that there is no portion for filling the recording head, and the ink can always be supplied to the recording head stably.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of an ink jet recording head cartridge of the present invention.

FIG. 2 is a configuration diagram illustrating an example of an ink storage unit.

FIG. 3 is a cross-sectional view illustrating a configuration near a relay section in an embodiment of the ink jet recording head cartridge of the present invention.

FIG. 4 is a cross-sectional view showing a state where an ink supply valve in FIG. 3 is closed.

FIG. 5 is a perspective view illustrating an example of an ink supply valve.

FIG. 6 is an explanatory diagram of ink supply.

FIG. 7 is a cross-sectional view illustrating another configuration near the relay section in an embodiment of the ink jet recording head cartridge of the present invention.

[Explanation of symbols]

1 recording head section, 2 ink storage section, 3 relay section, 4
Ink storage section mounting member, 5 recording head section mounting member,
6 ink supply pipe, 7 ink supply pipe insertion port, 8, 9
Electrical connector, 10 input / output terminals, 11 housing,
12 air communication port, 13 ink bag, 14 ink supply valve, 15 ink supply port, 21 ink relay member, 22
Ink holding member storage section, 23 Ink holding member, 24
Ink remaining amount sensor, 25 solenoid, 26 ink supply valve opening / closing member, 27 capillary tube, 28 opening, 29 pressure sensor.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 2/175

Claims (4)

(57) [Claims] 1. An ink jet recording head cartridge used in an ink jet recording apparatus, comprising: a recording head for performing recording by discharging ink; a negative pressure generating unit for supplying ink to the recording head; and an ink containing unit for containing ink. A connecting portion for connecting the ink containing portion and the negative pressure generating portion, and when there is no internal pressure difference between the ink containing portion and the negative pressure generating portion, An opening where ink is not dropped is provided, and when the internal pressure difference between the ink storage unit and the negative pressure generating unit exceeds the surface tension, the ink extruded from the opening is sent to the negative pressure generating unit, An ink jet recording head cartridge, wherein the ink storage section is configured to be detachable, and the ink storage section is replaceable. 2. The ink jet recording head cartridge according to claim 1, wherein a valve is provided between the ink containing section and the negative pressure generating section. 3. The ink jet recording head cartridge according to claim 1, wherein the recording head unit is configured to be detachable, and the recording head unit is replaceable. 4. The ink jet recording head cartridge according to claim 1, wherein the negative pressure generating section is mounted on a carriage of the ink jet recording apparatus.