JP3207677B2 - Ink tank and ink jet apparatus using the tank - 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 tank and an ink jet apparatus using the ink tank.

[0002]

2. Description of the Related Art Ink jet devices are used to print characters on paper, cloth, etc.
It is used as a device for attaching ink to any medium, including those for recording images and the like. The most common of these are printers,
2. Related Art An ink jet recording apparatus used for a copying machine or the like is known.

In this ink jet recording apparatus,
The miniaturization is one of the recent trends, and in such a case, the miniaturization and high efficiency of each element constituting the device are required. In such a case, in the ink tank, it is required to increase the storage efficiency as well as the size of the ink tank, and as a configuration for achieving this, the thickness of the ink tank container is reduced.

[0004] The reduction in the thickness of the container is not limited to the miniaturized ink tank, but is often adopted when the storage efficiency of the ink tank is to be increased.

[0005]

SUMMARY OF THE INVENTION However, the present inventors have discovered that the following problems occur in connection with reducing the thickness of the ink tank container. That is, not only does the ink tank cause a relative decrease in strength, but also the ejection stability of an inkjet head that performs ejection by receiving supply of ink from the ink tank is impaired.

FIGS. 1A and 1B are diagrams for explaining this problem.

For example, as shown in FIG. 1A, when recording a pattern in which solid recording for 6 dots is repeated at a head drive frequency of 6 kHz and then ejection suspension for 6 dots is repeated, an ink jet head is used. FIG. 1 (C)
A pulse-like pressure fluctuation having a period of 2 msec as shown by c in FIG. Then, the pressure fluctuation propagates to the ink tank communicating with the ink jet head and causes an oscillating force to act on the ink tank.

On the other hand, each part of the ink tank container vibrates due to the action of the pressure fluctuation due to the ejection of the ink jet head. However, when the pressure due to the ejection as shown by a in FIG. As shown in b, the vibration rapidly attenuates and does not affect the subsequent ink supply.

However, in the case of the pressure fluctuation as shown in FIG. 1C, the natural frequency of the ink tank is changed to the frequency of the force acting on the ink tank (500 Hz (2 ms in the illustrated example).
ec)), a resonance state occurs when
The pressure fluctuation of the ink in the ink tank also becomes as shown by d in FIG. That is, the pressure oscillation of the ink does not cause an effective attenuation, which results in poor ink supply thereafter, which results in defective ejection and ink leakage.

The present invention has been made in view of such a problem. It is an object of the present invention to minimize a decrease in the storage efficiency of an ink tank and minimize the occurrence of a discharge associated with ejection. An object of the present invention is to provide an ink tank capable of controlling undesired pressure fluctuations and an ink jet apparatus using the ink tank.

[0011]

According to the present invention, there is provided:
In an ink tank storing ink to be supplied to an ink jet head, a tank forming member for forming a storage portion for storing ink, and the tank forming member is added to the tank forming member or replaced with a part of the member, A member for changing the natural frequency of the forming member, and a plurality of members for changing the natural frequency are provided so as to be shifted from the frequency of the pressure vibration appearing by the ejection of the inkjet head. It is characterized by being.

In another embodiment, in an ink tank storing ink to be supplied to an ink jet head, the frequency of the pressure vibration generated by the ejection of the ink jet head is shifted to the outside of a wall forming a case of the ink tank. A plurality of members for increasing the thickness of the wall are provided.

In still another embodiment, in an ink tank storing ink to be supplied to an ink jet head, the frequency of a pressure vibration generated by ejection of the ink jet head is shifted inside a wall forming a case of the ink tank. A plurality of members made of a material different from the material of the wall are provided.

An ink jet apparatus using an ink jet head for discharging ink from the head to a medium, comprising an ink tank storing ink to be supplied to the ink jet head, wherein the ink tank has a storage tank for storing ink. A tank forming member for forming a portion, and a member added to the tank forming member, or replaced with a part of the member, for changing a natural frequency of the tank forming member. A plurality of members for changing the natural frequency are provided so as to be shifted from the frequency of the pressure vibration appearing by the ejection of the ink jet head.

According to another aspect of the present invention, there is provided an ink jet apparatus for discharging ink to a medium from the head using an ink jet head, comprising: an ink tank storing ink to be supplied to the ink jet head; A plurality of members for increasing the thickness of the wall are provided outside the wall forming the case of the tank so as to be deviated from the frequency of the pressure vibration appearing by the discharge of the ink jet head.

According to still another aspect of the present invention, there is provided an ink jet apparatus that uses an ink jet head and discharges ink from the head to a medium, comprising an ink tank storing ink to be supplied to the ink jet head.
The ink tank is characterized in that a plurality of members made of a material different from the material of the wall are provided inside a wall forming a case of the ink tank so as to be shifted from a frequency of a pressure vibration appearing by ejection of the ink jet head. .

[0017]

According to the above construction, the oscillating pressure of the ink generated by the discharge of the ink jet head is transmitted to the ink tank, but appears on the wall or the tank forming member forming the case of the ink tank by the discharge of the ink jet head. A predetermined member is provided so as to be shifted from the frequency of the pressure vibration, or a member of a different material is provided, so that the natural frequency of the ink tank can be shifted from the frequency of the ejection pressure vibration. It is possible to prevent the occurrence of a resonance state due to the pressure of ink in the ink tank, to enable quick attenuation of the ink vibration, and to reduce the influence of the ink vibration on the subsequent ink supply to the ink jet head. it can.

[0018]

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

(Embodiment 1) FIG. 2 is a perspective view showing an ink cartridge as an ink tank according to an embodiment of the present invention, and FIG. 3 (A) is a front view and a side view partially cut away. is there. FIG. 3B is a front view showing an ink cartridge of another embodiment according to the present embodiment, and a side view showing a partially broken section. That is, the ink cartridge of this embodiment is used for an ink jet printer described later, and the cartridge shown in FIGS. 2 and 3A stores black (Bk) ink. Are for storing cyan (C), magenta (M), and yellow (Y) inks, respectively. As shown in FIGS. 2 and 3 (A),
Since the consumption of Bk ink tends to be larger than that of inks of other colors, an extra ink chamber 12A is provided to increase the amount that can be stored.

As shown in these figures, an ink supply port 2 is provided on an end face of the ink cartridge 1. When the cartridge 1 is mounted on a carriage (not shown) of the printer, it is provided on the ink jet head side. A supply pipe (not shown) is inserted through the supply port 2 and comes into contact with the absorber 7 therein. In addition, an outer opening of the atmosphere communication port 3 is provided on a surface on which the supply port 2 is provided. This opening communicates with the inside opening of the atmosphere communication port 3 through a tube formed inside the case member of the cartridge. This inside opening is provided on the upper surface side of the cartridge 1 and faces an absorber chamber described later.

The ink storage section of the ink cartridge 1
Consists of two rooms. That is, the absorber chamber 11 as a negative pressure generating member accommodating chamber, which is filled with the absorber 7, generates an apparent negative pressure with respect to the atmosphere by the capillary force and holds the ink.
And an ink chamber 12 whose cavity is filled with ink.

These two chambers are separated from each other by a partition wall 5. The partition wall 5 does not partition the entire chamber, but communicates with each other via an ink passage 6 provided below the partition. As a result, the ink in the absorber chamber 11 is consumed first, and when the liquid level decreases to the level indicated by the groove 5A of the partition wall 5, gas-liquid exchange via the ink passage 6 starts, and the ink in the ink chamber 12 is consumed. By using the two-chamber structure of the ink cartridge in this way, it is possible to achieve both good ink storage efficiency and good ink supply performance.

A reinforcing rib 4 is provided in the ink chamber 12 (see FIG. 3B) of the cartridge 1 for the C, M, and Y inks.

On one side of the ink cartridge 1,
As one embodiment of the present invention, five ribs 15 are provided.
The ribs 15 have a width of 1.9 mm and a thickness of 0.6 mm, and are arranged at a pitch of 3.4 mm via a groove having a width of 1.5 mm. The size of the cartridge 1 having such a rib (the size of a substantially rectangular parallelepiped portion excluding the ink chamber 12A in the cartridge of FIGS. 2 and 3A) is 48 mm in length, 11 mm in width, and 35 mm in height. It is.

FIGS. 4A to 4C are diagrams for explaining the effect of providing a rib on the ink cartridge.

FIG. 4A shows the fluctuation of the ink pressure inside the ink cartridge due to the natural vibration of the ink cartridge when no rib is provided. That is, the thickness of the cartridge case member of the absorber chamber 11 of the cartridge 1 is usually 1 to
The thickness is set to 2 mm, but in the case of this thickness, the ink inside the ink jet head is affected by the pressure fluctuation due to the ejection of the ink jet head, so that the ink inside the ink jet vibrates at the pressure shown in FIG. As shown in this figure, when no rib is provided, the vibration has a low frequency and a slow attenuation (time t ₁ ). Since this frequency is close to the frequency of the recording pattern in a normal printer or the like as described above, resonance may be caused.

On the other hand, FIGS. 4B and 4C show the case where ribs are provided, and the tendency is that the frequency becomes higher and the decay times (t ₂ , t ₃ ) become shorter. The difference between FIGS. (B) and (C) is due to the difference in the rib arrangement pitch P. FIG. (B) shows the case where P is 4 mm or more, and FIG. (C) shows the case where P is 4 mm or less. Show. As described above, the shorter the pitch P is, the more advantageous from the viewpoint of the decay time. However, in consideration of the frequency of the recording pattern, the pitch P is set to 3.4 mm as described above in the present example.

By the way, when a rib is provided in an ink tank having only an absorber inside as conventionally known, the rib is provided inside the tank wall 9 as shown in FIG. 5 to maintain the air supply performance. At the same time, pressure vibration was suppressed. However, as in the above-described embodiment of the present invention, in a configuration in which an absorber is not provided partially, that is, in a configuration having a hollow ink chamber, the tank wall and the absorber are in close contact with each other in terms of ink supply control such as gas-liquid exchange. The performance is very important, and if there is even a small gap between the tank wall and the absorber, the ink supply performance will be reduced.

The cause is that the groove 5 of the barrier 5 described above with reference to FIG.
This is because a principle similar to the principle of A works. That is,
When ribs are provided on the inner wall of the absorber chamber 11, the grooves 5
The ink level is controlled in the gap between the ribs by the same operation as A, and there is a possibility that the negative pressure cannot be stably controlled in the entire tank.

For this reason, a rib cannot be provided inside the tank structure in which only a part is the absorber. In this case, it is conceivable to suppress the vibration by increasing the thickness of the tank wall, but it is not possible to obtain the effect of suppressing the pressure vibration to such an extent that the storage efficiency decreases due to the increase in the thickness. The vibration amplitude is not reduced only by shortening the period. Further, when the thickness is simply increased, so-called "sink" is caused by molding, and the distortion of the tank may be increased.

On the other hand, by providing the vibration suppressing rib 15 outside the ink tank wall as in the above embodiment,
The natural frequency can be changed (increased) and the amplitude and the decay time of the pressure vibration can be reduced without significantly lowering the storage efficiency.

As shown in FIG. 3A, when the ribs 15 are provided over both the absorber chamber 11 and the ink storage chamber 12, the natural frequencies of the respective chambers are averaged while averaging the natural frequencies of the respective chambers. The frequency can be adjusted.

The ink chamber and the absorber chamber are approximately 1:
In such a case, the rib may be interposed in one of the ribs. For example, FIG. 3B shows a case where a rib is provided in the absorber chamber. However, it is preferable that a rib be provided in the ink chamber. More preferably, ribs may be extended on both sides of the ink chamber and the absorber chamber. The reason is that the ink chamber is more susceptible to vibration due to the swing of the carriage and the like than the absorber chamber, and is more likely to affect printing.

On the other hand, when the area ratio between the ink chamber and the absorber chamber deviates significantly from 1: 1, it is preferable that the rib is on the side having a larger area. This is because if the area of the tank is large, it tends to vibrate and easily affect printing.
Therefore, in the embodiment of the present invention, it is preferable that the absorber chamber has a rib. Also, the rib is an ink chamber,
It is preferable that the ribs are provided independently on both sides of the absorber chamber, and it is particularly preferable that the ribs extend integrally on both sides as shown in FIG.

(Embodiment 2) FIG. 6 shows an ink cartridge according to another embodiment of the present invention, and a side surface of an ink cartridge for C, M, and Y ink similar to that shown in FIG. 3B. FIG.

In the cartridge of this embodiment, the arrangement pitch of the ribs 15 is changed, so that the natural frequency can be set higher and the vibration itself can be suppressed as in the above embodiment. Become.

That is, if the width between the ribs, which mainly generate pressure vibration, is the same, the vibration frequency may be the same and the amplitudes may be increased. However, by making these intervals P ₁ , P ₂ , P ₃ different from each other,
As shown in FIGS. 7A to 7C, the periods of the respective vibrations can be made different. As a result, the combined pressure signal of the entire ink cartridge is as shown in FIG. 4D, and the amplitude thereof can be suppressed to a small value.

(Embodiment 3) FIG. 8 is a front view of an ink cartridge according to still another embodiment of the present invention.

In the present embodiment, the space at the time of mounting on the recording apparatus is effectively used, and as a result, a decrease in the storage efficiency of the ink tank is suppressed. That is, the rib 1
When the cartridges 5 are provided on both sides of the cartridge, the positions of the cartridges 5 are shifted from each other as shown in FIG. 4A, so that when the apparatus is mounted as shown in FIG. The arrangement is such that the ribs 15 of the cartridges 1 overlap each other with a certain distance therebetween, thereby effectively utilizing the device space, and as a result, the storage efficiency of each cartridge can be suppressed from being reduced due to the provision of the ribs.

(Embodiment 4) FIG. 9 is a view showing an ink cartridge according to still another embodiment of the present invention.

In this embodiment, instead of providing ribs on the tank wall, a material 16 having another strength is provided, thereby changing the natural frequency and suppressing the pressure vibration.

According to this embodiment, as in the above embodiments, it is possible to effectively prevent ink supply failure and the like due to pressure vibration, and to prevent the storage efficiency of the cartridge mounting space from being reduced at all. Can be obtained.

Also in this embodiment, the arrangement pitch of the members may be set to 4 mm or less, and the pitch may be different for each interval.

(Embodiment 5) FIG. 10 is a view showing an ink cartridge according to still another embodiment of the present invention.

In the present embodiment, by providing the ribs 15 in a lattice shape, it is possible to obtain an effect of changing the natural frequency to prevent resonance and further suppressing vibration.

The number of ribs, the thickness, the arrangement pitch, and the material when different materials are used as described in each of the above-described embodiments are simply changed by changing the natural frequency of the ink tank and suppressing the vibration. It is desirable not only to take into account, but also to determine the recording pattern that frequently appears in the device in which the ink tank is used, so that it is possible to more effectively maintain good ink supply properties and the like. Become.

In addition to providing ribs on the outer wall and changing the material, another material may be attached to the outer wall, or the material may be made detachable so as to more effectively correspond to the recording pattern. It may be.

FIG. 11 is a perspective view showing a printer as an ink jet recording apparatus using the ink cartridge according to the present invention.

In FIG. 11, reference numeral 101 denotes a printer, 102 denotes an operation panel section provided at the front of the upper surface of the housing of the printer 101, and 103 denotes a paper feed cassette mounted through an opening at the front of the housing. , 1
04 is the paper (recording medium) supplied from the paper feed cassette 3
Reference numeral 105 denotes a paper discharge tray for holding the paper discharged through the paper conveyance path in the printer 101. 10
Reference numeral 6 denotes a body cover having an L-shaped cross section. The main body cover 106 covers an opening 107 formed in the right front part of the housing, and is rotatably attached to an inner end of the opening 107 by a hinge 108. A carriage 110 supported by a guide or the like (not shown) is provided inside the housing.
The carriage 110 is provided so as to be able to reciprocate along the width direction of the paper passing through the paper transport path, that is, the longitudinal direction of the guide 9 and the like.

The carriage 110 in this embodiment has a stage 110a which is held horizontally by a guide or the like,
An opening (not shown) formed on the stage 110a and near the guide for mounting an ink jet head, and the ink cartridges 1Y, 1M, 1C, and 1B mounted on the stage 110a in front of the opening.
a cartridge garage 110b for accommodating k.
The garage 110b is roughly constituted by a cartridge holder 110c for preventing the cartridge housed in the garage 110b from being detached.

The stage 110a is slidably supported at its rear end by the guide, and the lower side of its front end is mounted on a guide plate (not shown). The guide plate may function as a paper holding member for preventing the paper conveyed on the above-described paper conveyance path from rising, and the stage may be cantilevered relative to the guide according to the thickness of the paper. It may have a function of lifting the object.

An ink jet head (not shown) is mounted on the opening of the stage 110a with its ink discharge port directed downward.

The cartridge garage 110b has four
A through-hole for accommodating the ink cartridges 1Y, 1M, 1C, and 1Bk at the same time is formed in the front-rear direction, and engagement recesses with which engagement claws of the cartridge holder 110c engage are formed on both outer sides. I have.

The cartridge holder 10c is rotatably attached to the front end of the stage 110a by a hinge 116. The dimension from the front end face of the garage 110b to the hinge 116 is determined in consideration of the dimension of the cartridge 1Y, 1M, 1C, 1Bk projecting from the front end of the garage 110b when the cartridge 1Y is accommodated in the garage 110b. . The cartridge holder 11
0c is a substantially rectangular plate shape. Cartridge holder 11
0c, the garage 11 protrudes in the direction perpendicular to the plate surface on both sides of the upper part away from the lower part fixed by the hinge 116, and when the holder 110c is closed.
A pair of engaging claws 110 engaging with the engaging recess 110d
e is provided. In the holder 10c, a fitting hole 120 for fitting the handle of each of the cartridges 1Y, 1M, 1C, 1Bk is formed in its plate portion.
These fitting holes 120 have a position, a shape, and a size corresponding to the handle.

[0055]

As described above, according to the present invention,
The oscillating pressure of the ink generated by the ejection in the ink jet head propagates to the ink tank.
Since a predetermined member is provided or a member of a different material is provided so as to be shifted from the frequency of the pressure vibration appearing by the ejection of the ink jet head, the natural frequency of the ink tank is shifted from the frequency of the ejection pressure oscillation. Accordingly, it is possible to prevent the occurrence of a resonance state due to the pressure of the ink in the ink tank, to enable the ink vibration to be rapidly attenuated, and to cause the ink vibration to affect the subsequent ink supply to the ink jet head. The influence can be reduced.

As a result, it is possible to provide an ink tank capable of suppressing a decrease in the storage efficiency of the ink tank and constantly supplying good ink.

[Brief description of the drawings]

FIGS. 1A, 1B, and 1C are explanatory diagrams for explaining a problem of a conventional technique.

FIG. 2 is an external perspective view of an ink cartridge according to one embodiment of the present invention.

FIGS. 3A and 3B are diagrams illustrating an ink cartridge according to an embodiment of the present invention.

FIGS. 4A, 4B, and 4C are diagrams for explaining effects when the ink cartridge of the embodiment is used.

FIG. 5 is a cross-sectional view showing one structure of an ink tank using an ink absorber.

FIG. 6 is a view showing an ink cartridge according to another embodiment of the present invention.

FIG. 7 is a diagram for explaining an effect of the embodiment shown in FIG. 6;

FIGS. 8A and 8B are diagrams showing an ink cartridge according to still another embodiment of the present invention.

FIG. 9 is a view showing an ink cartridge according to still another embodiment of the present invention.

FIG. 10 is a view showing an ink cartridge according to still another embodiment of the present invention.

FIG. 11 is an external perspective view showing a printer using an ink cartridge to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink cartridge 2 Ink supply port 3 Atmospheric communication port 4 Rib 5 Partition wall 6 Ink passage 7 Absorber 11 Absorber chamber 12, 12A Ink chamber 15 Rib 16 Another member

Continuation of the front page (72) Inventor Genji Inada 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-4-185355 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41J 2/175

Claims (19)

(57) [Claims] 1. An ink tank storing ink to be supplied to an ink jet head, comprising: a tank forming member for forming a storage section for storing ink; and a tank added to or part of the tank forming member. It is replaced, and the member for changing the natural frequency of the tank formation member, and comprises a, the member for changing the said intrinsic frequency vibration thus appearing pressure for ejecting the ink-jet head
An ink tank , wherein a plurality of ink tanks are provided so as to be shifted from a frequency of motion . 2. An ink tank storing ink to be supplied to an ink-jet head, wherein the ink is provided outside a wall forming a case of the ink tank.
Oscillation of pressure oscillation caused by jet head ejection
An ink tank comprising a plurality of members that increase the thickness of the wall so as to be shifted from the number . 3. The ink tank according to claim 2, wherein the member that increases the thickness of the wall is a rib that extends in a predetermined direction in the case. 4. The ink tank according to claim 3, wherein the plurality of ribs are arranged at a predetermined pitch. 5. The ink tank according to claim 4, wherein the predetermined pitch is 4 mm or less. 6. The ink tank according to claim 3, wherein the plurality of ribs are arranged at different pitches. 7. The ink tank according to claim 3, wherein the ribs are provided on two opposing surfaces of the case of the ink tank, and the arrangement positions of the plurality of ribs on the respective surfaces are shifted from each other. The ink tank according to any one of the above. 8. An ink tank storing ink to be supplied to an ink jet head, wherein said ink tank is provided inside a wall forming a case of said ink tank.
Frequency of pressure oscillation caused by jet head discharge
An ink tank comprising a plurality of members made of a material different from the material of the wall so as to be shifted from the wall. 9. The ink tank according to claim 8, wherein the member is provided corresponding to a predetermined ejection cycle that appears in the ejection of the inkjet head. 10. The ink tank according to claim 8, wherein a plurality of the members extend in a predetermined direction inside the wall. 11. The ink tank according to claim 10, wherein the plurality of members are arranged at a predetermined pitch. 12. The ink tank according to claim 11, wherein the predetermined pitch is 4 mm or less. 13. The ink tank according to claim 11, wherein the plurality of members are arranged at different pitches. 14. The storage section includes a negative pressure generating member housing chamber for housing a negative pressure generating member, and a hollow ink chamber adjacent to the negative pressure generating member housing chamber for storing ink communicated with a bottom communication portion. The ink tank according to any one of claims 1 to 13, comprising: 15. An ink jet apparatus using an ink jet head for discharging ink from the head to a medium, comprising: an ink tank for storing ink to be supplied to the ink jet head, wherein the ink tank has a storage for storing ink. A tank forming member for forming a portion, and a member added to the tank forming member or replaced with a part of the member to change a natural frequency of the tank forming member. , the member for changing the said intrinsic frequency vibration thus appearing pressure for ejecting the ink-jet head
An ink jet apparatus , wherein a plurality of ink jet apparatuses are provided so as to be shifted from a frequency of motion . 16. An ink jet apparatus using an ink jet head for discharging ink from the head to a medium, comprising an ink tank storing ink to be supplied to the ink jet head, wherein the ink tank is a case of the ink tank. Outside of the wall making the ink
Oscillation of pressure oscillation caused by jet head ejection
An ink jet apparatus comprising a plurality of members which increase the thickness of the wall so as to be shifted from the number . 17. An ink jet apparatus using an ink jet head for discharging ink from the head to a medium, comprising an ink tank storing ink to be supplied to the ink jet head, wherein the ink tank is a case of the ink tank. The ink jet inside the wall
Frequency of pressure oscillation caused by jet head discharge
An ink jet apparatus comprising a plurality of members made of a material different from the material of the wall so as to be shifted from the wall. 18. An ink jet apparatus according to claim 15, wherein said ink tank is detachably mounted on said ink jet apparatus. 19. The ink jet head according to claim 15, wherein bubbles are generated in the ink by using thermal energy, and the ink is ejected with the generation of the bubbles. An inkjet device according to item 1.