JPH08267775A - Ink tank, ink jet unit and ink jet printer - Google Patents

Abstract

PURPOSE: To provide an ink tank for refilling ink without generating the overflow of ink, an ink jet unit and an ink jet printer thereof. CONSTITUTION: In an ink jet unit Y provided with a printing head 1 and an ink tank 2, an atmosphere communicating opening 8 used combinedly as an opening for refilling ink 7 and electrodes 4a and 4b are provided in the ink tank 2, and when the storage amount of ink 7 in the ink tank 2 reaches the full filling amount and the refilling is completed, the variation of electric resistance between electrodes 4a and 4b is finished by a controller, and the full amount of ink 7 is informed to a user.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink tank, an ink jet unit, and an ink jet printer equipped with the ink tank.

The present invention is applicable to all devices using paper, cloth, leather, non-woven fabric, OHP paper and the like, as well as a printing medium such as metal. Specific applicable equipment includes office equipment such as printers, copying machines, and facsimiles, and industrial production equipment.

[0003]

2. Description of the Related Art Recently, a cartridge type ink jet unit in which a print head and an ink tank are integrated is used in a popular machine of an ink jet printer. The ink jet unit is mounted on a carriage and the carriage is scanned. To record. This ink jet unit is used by replacing it with a new ink jet unit when the ink in the ink tank is exhausted.

However, the life of the print head is long with respect to the amount of ink stored in the ink tank of the ink jet unit, and even when the ink of the ink jet unit is consumed, the print head is still in a usable state. . It is not preferable to dispose of such an inkjet unit in terms of resources and environment.

Therefore, it has been proposed to refill the ink tank of such an ink jet unit with ink. For example, Gragic Utility Co., Ltd. attaches a metal syringe to a bellows type ink container, makes a hole in the ink tank, inserts a needle of the syringe into the hole, and manually inserts the bellows type ink container. It adopts a form in which the ink is refilled into the ink tank by gradually crushing and pressurizing. Further, there is also one in which the ink container is in the form of a syringe and ink is filled under pressure.

[0006]

However, in the ink refilling machine of such a form, the user cannot know the amount of ink in the ink tank. Therefore, when refilling the ink, there is a high risk that the ink will overflow to the outside of the ink tank due to the excessive filling of the ink. If ink is refilled while the inkjet unit is installed in the printer, overflow of ink may cause problems such as damage to the printer or stains on the recorded matter. It was necessary to remove the inkjet unit from the printer. Therefore, fix the inkjet unit removed from the printer,
A device was provided to allow refilling of the ink. Furthermore, in order to refill the ink so that the ink does not overflow, it is necessary to maintain the pressurized state of the ink container to a predetermined level, which complicates the structure of the ink container and refills the ink. Therefore, there are many problems, and there is a problem that the time for restraining the user for ink filling becomes long. In order to prevent ink overflow when refilling ink, there is also a method of first removing all the ink remaining in the ink tank and then injecting a fixed amount of ink, but there is a problem of processing the removed ink. There is a problem that the device becomes complicated.

As described above, conventionally, when the ink tank of the ink jet unit is refilled with the ink, the ink overflows and the user and the surroundings of the ink tank are contaminated with the ink. . This is
The same applies when ink is refilled in an ink tank attached to an inkjet printer separately from the print head.

An object of the present invention is to provide an ink tank, an ink jet unit, and an ink jet printer which can refill the ink tank without causing the ink to overflow.

[0009]

The ink tank of the present invention is an ink tank capable of containing ink,
It is characterized in that it has a hole for refilling the inside of the ink and a detection means for detecting the amount of the contained ink.

An ink jet unit of the present invention is characterized by comprising the above ink tank and an ink jet head to which the ink is supplied from the ink tank and which can eject the ink.

An ink jet printer of the present invention comprises the above ink tank, an ink jet head which is supplied with the ink from the ink tank and which can eject the ink toward a print medium, the ink jet head and the print medium. And a moving means for moving the and relative to each other.

[0012]

In the present invention, when the ink is refilled, the amount of ink contained in the ink tank is detected to prevent the ink from overflowing from the ink tank.

[0013]

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

(Embodiment 1) FIG. 1 is a perspective view of an ink jet unit Y according to the present invention. In FIG. 1, 1 is a print head, 2 is an ink tank, 3 is a printed circuit board, 4a and 4b are electrodes provided in the ink tank 2, and 8
Is a hole for refilling ink, which also serves as an atmosphere communication port. Here, the electrode 4 a is directly connected to the printed board 3, and the electrode 4 b is connected to the printed board 3 via the leaf spring 5. As will be described later, the electrode 4b is provided at the liquid surface position when the amount of ink stored in the ink tank 2 reaches the full filling amount at which refilling is completed, and the electrode 4a is provided below the electrode 4b. Has been.

FIG. 2 shows the bellows portion 14a and the ink inflow /
Ink refilling tool 14 including the outflowing tip portion 14b
An example is shown below. The ink refilling tool 14 has a bellows part 14
By expanding and contracting a, ink is taken out from the ink refill tank (not shown) into the bellows part 14a through the tip part 14b, and then the tip part 14b is inserted into the atmosphere communication port 8 and the bellows part 14a is expanded and contracted. By this, the ink tank 2 is refilled with the ink in the bellows portion 14a.

FIG. 3 is a sectional view of the ink jet unit Y shown in FIG. In FIG. 3, 6 is a valve means for enhancing the ink supply pressure to the print head 1, and 7 is ink. In this embodiment, the valve means 6 comprises a resilient bulkhead partition with a crack at the upper end. Valve means 6
Is deformed as the negative pressure in the recording head 1 increases due to ink consumption such as recording, and eventually the ink 7 in the ink tank 2 flows into the print head 1 through the cracked portion to supply a predetermined ink. Can hold pressure.

FIG. 4 is a block diagram showing the configuration of the control circuit 100 of the ink jet printer. In FIG. 4, 108 is an interface for inputting a recording signal, 1
Reference numeral 01 is an MPU, 102 is a ROM that stores a control program executed by the MPU 101, and 103 is a DRAM that saves various data (the above-described recording signals and recording data supplied to the print head 1). Reference numeral 104 denotes a gate array (GA) that controls supply of print data to the print head 1, and includes an interface 108 and an MP.
It also controls the data transfer of U101, RAM103 and the like. 1
Reference numeral 10 is a carrier motor for scanning a carrier on which a print head is mounted, and 109 is a transport motor for transporting recording paper. Reference numeral 105 is a head driver for driving the print head 1, and 106 and 107 are motor drivers for driving the carry motor 109 and the carrier motor 110, respectively. The operation of the control circuit will be described. When a recording signal is input to the interface 108, the recording signal is converted between the gate array 104 and the MPU 101 into recording data for printing. Then, the motor drivers 106 and 107 are driven, and the print head 1 is driven according to the recording data sent to the head driver 105 to perform recording. Further, the ink tank 2 is connected with signal lines 111 and 112 for applying a constant voltage from the control circuit 100 to the electrodes 4a and 4b provided in the ink 2. Further, the control circuit 100 also controls the display device 113 for notifying the user of the status of the printer or the inkjet unit.

FIG. 5 is a schematic perspective view showing a main part of an example of an ink jet printer provided with the ink jet unit Y. As shown in FIG.

In this example, the ink jet unit Y
The print head 1 of FIG. 2 has, for example, 64 ink ejection ports (not shown) in the conveying direction of the recording paper 37 on the surface facing the recording paper 37. In addition, the print head 1 has 6
An ink path (not shown) is provided so as to communicate with each of the four ejection ports, and electrothermal conversion that generates thermal energy for ejecting ink to a substrate that constitutes the print head 1 corresponding to each ink path. The body is formed. The electrothermal converter generates heat by an electric pulse applied thereto according to the drive data, whereby film boiling occurs in the ink, and the ink is ejected from the ejection port as bubbles are generated by the film boiling. Is ejected. Each ink path is provided with a common liquid chamber that communicates with them in common, and the ink from the ink tank 2 stored in this common liquid chamber is the ink path depending on the ejection operation in each ink path. Is supplied to.

The carriage 32 mounts the ink jet unit Y in a replaceable manner by means not shown, and
It is slidably engaged with a pair of guide rails 33 extending in parallel with the recording surface of the recording paper 37. As a result, the print head 1 can move along the guide rail 33, and along with this movement, recording is performed by ejecting ink toward the recording surface at a predetermined timing. After the above movement, the recording paper 37 is conveyed by a predetermined amount in the direction of the arrow in the figure, and the above movement is performed again for recording. By repeating such an operation, recording is sequentially performed on the recording paper 7.

The above-mentioned conveyance of the recording paper 37 is carried out by a pair of conveying rollers 34 arranged above and below the recording surface.
And 35 are rotated. A platen 36 for maintaining the flatness of the recording surface is provided on the back side of the recording surface of the recording paper 37.

The movement of the carriage 32 described above is
This is made possible by driving, for example, a belt (not shown) attached to this by the carrier motor 110 (see FIG. 4), and the rotation of the transport rollers 34 and 35 is also rotated by the transport motor 109 (see FIG. 4). It becomes possible by being transmitted to these.

Next, the operation of the ink-jet unit Y and the ink-jet printer having the above-mentioned configurations when ink is refilled (hereinafter, also referred to as "refill") will be described.

First, an ink jet refilling mode is set by pushing an ink refilling switch (not shown). As a result, a voltage is applied to the electrodes 4a and 4b via the signal lines 111 and 112, and the control circuit 100
Monitors the resistance value between the electrodes 4a and 4b. After that, the user inserts the tip portion 14b of the ink refilling tool 14 containing the ink into the air communication port 8 of the ink tank 2 to start refilling of the ink 7. When the refilling of the ink 7 progresses and the liquid surface reaches the position of the electrode 4b, the electrodes 4a, 4b
The resistance between them changes. This resistance change is controlled by the control means 100.
Is detected, and the fact that the ink 7 in the ink tank 2 is full is displayed on the display device 113 to inform the user. In response to this, the user stops the refilling of the ink 7 to prevent the ink 7 from overflowing from the ink tank 2.

As described above, in this embodiment, when the ink is refilled, it is possible to prevent the ink from overflowing from the ink tank 2, so that the user and the periphery of the ink tank 2 are not contaminated with the ink. Also, since there is no ink overflow,
Ink refilling can be performed on the main body of the inkjet printer, and a special ink refilling machine or the like is not necessary.

In this embodiment, an example in which the ink is refilled from the atmosphere communication port 8 has been described, but an ink refill hole may be provided separately from the atmosphere communication port 8. However, this hole is preferably covered with a tape, a cap, or the like at the end of refilling from the viewpoint of preventing evaporation and leakage of ink.

(Embodiment 2) FIG. 6 is a sectional view showing a second structural example of an ink jet unit Y according to the present invention.

In this embodiment, the ink tank 2 is provided with three electrodes 4a, 4b and 4c. The ink jet printer is provided with three signal lines (not shown) connected to these electrodes 4a, 4b, 4c, and the display device 113
(See FIG. 4) displays two types of contents as described later. In this embodiment, similarly to the above-described embodiments, the display device 113 informs the user that the ink 7 in the ink tank 2 is full by detecting the change in the resistance value between the electrodes 4a and 4b. . Further, in the present embodiment, by detecting the change in the resistance value between the electrodes 4a and 4b, it is detected that the ink 7 in the ink tank 2 is running low, and the display device 113 displays the ink 7 before the ink 7 is exhausted. The user can be prompted to refill the ink 7. Therefore, the electrode 4c is provided at the liquid surface position when the storage amount of the ink 7 in the ink tank 2 decreases until it needs to be refilled.

As a result of these, the user can refill the ink in the required amount at the required time.

(Embodiment 3) FIG. 7 is a sectional view showing a third structural example of an ink jet unit Y according to the present invention.

In this embodiment, 10 is a hole for refilling ink, 11 is an O-ring, 12 is a flexible member provided under the atmosphere communication port, 13 is a float that floats on the ink 7, and 9 is a float 13. It is a wall that regulates movement.

When the line end portion 14b of the ink refilling tool 14 is inserted into the refilling hole 10 during refilling, the tip end portion 14 thereof is
An O-ring 11 seals between the outer peripheral surface of b and the inner peripheral surface of the hole 10. In this state, the ink 7 is refilled, and the float 13 rises as the liquid level rises,
The float 13 eventually contacts the flexible member 12.
As a result, the atmosphere communication port 8 is closed and the inside of the ink tank 2 is shut off from the outside air, and the ink 7 cannot enter any more, and the user can know that the ink 7 is full.

In the present embodiment, the user is not shown to be full of ink, but the float 1
It is also possible to detect the position of 3 and inform the user of the fullness by the display device 113 (see FIG. 4). As a result, it is possible to inform the user of the ink fullness in an easy-to-understand manner.

(Other Embodiments) In the above-described Embodiments 1 and 2, an example in which the amount of ink is detected by the change in the resistance value between the electrodes has been described, but the amount of ink is absorbed or reflected by the presence or absence of ink. It is also possible to use an optical method for detecting the above or a method for detecting the position of the float floating in the ink.

The present invention can also be applied as an ink tank that does not form the ink jet unit Y, that is, as an ink tank that is attached to an ink jet printer separately from the print head, and the ink tank can always be replaced with an ink jet printer. It is not necessary to be attached to, but may be fixedly attached.

(Others) The present invention is provided with a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for ejecting ink, particularly in the ink jet recording system. The present invention brings about excellent effects in a recording head and a recording apparatus of the type in which the state of ink is changed by the heat energy. This is because such a system can achieve high density recording and high definition recording.

Regarding the typical structure and principle thereof, see, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling is caused on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal in a one-to-one correspondence
It is effective because bubbles can be formed inside. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. It is more preferable to make this drive signal into a pulse shape because bubbles can be immediately and appropriately grown and contracted, so that liquid (ink) ejection with excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
The structure using the specification of No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration corresponding to the ejection portion is disclosed in JP-A-59-138461. That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full line type recording head having a length corresponding to the maximum width of a recording medium which can be recorded by the recording apparatus. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads or a configuration as one recording head integrally formed.

In addition, even in the case of the serial type as in the above example, the recording head fixed to the apparatus main body, or the electrical connection with the apparatus main body or the ink from the apparatus main body by being attached to the apparatus main body The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is integrally provided in the recording head itself is used.

Further, as the constitution of the recording apparatus of the present invention, it is preferable to add ejection recovery means of the recording head, preliminary auxiliary means, etc. because the effects of the present invention can be further stabilized. Specifically, heating is performed by using a capping unit, a cleaning unit, a pressure or suction unit for the recording head, an electrothermal converter or a heating element other than this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.

Regarding the type or number of recording heads to be mounted, for example, only one is provided corresponding to a single color ink, or a plurality of inks having different recording colors and densities are supported. A plurality of pieces may be provided. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but it may be either the recording head is integrally formed or a plurality of combinations may be used. The present invention is also extremely effective for an apparatus provided with at least one of full-color recording modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. Or, in the inkjet system, it is common to control the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. Sometimes, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy of the state change from the solid state of the ink to the liquid state, or in order to prevent the evaporation of the ink, it is solidified and heated in the standing state. You may use the ink liquefied by. In any case, by applying heat energy such as ink that is liquefied by applying heat energy according to the recording signal and liquid ink is ejected or that begins to solidify when it reaches the recording medium. The present invention can be applied to the case where an ink having a property of being liquefied for the first time is used. In this case, the ink is
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent No. 1260, it may be configured to face the electrothermal converter in a state of being held as a liquid or a solid in the concave portion or the through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the ink jet recording apparatus of the present invention may be used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function. It may be a form or the like.

[0045]

As described above, according to the present invention, it is possible to prevent ink from overflowing from the ink tank by detecting the amount of ink stored in the ink tank when refilling the ink. As a result, the user and the surroundings of the ink tank are not contaminated with ink. Further, since the ink does not overflow, the ink refilling can be performed on the inkjet printer main body, and a special ink refilling machine or the like is not required.

[Brief description of drawings]

FIG. 1 is a perspective view of an inkjet unit according to a first embodiment of the present invention.

FIG. 2 is a side view showing an example of an ink refilling tool.

FIG. 3 is a cross-sectional view of the inkjet unit shown in FIG.

FIG. 4 is a block diagram showing an example of a control system of the inkjet printer of the present invention.

FIG. 5 is a perspective view showing a configuration example of a main part of the inkjet printer of the present invention.

FIG. 6 is a cross-sectional view of an inkjet unit according to a second embodiment of the present invention.

FIG. 7 is a cross-sectional view of an inkjet unit according to a third embodiment of the present invention.

[Explanation of symbols]

 1 Printhead 2 Ink Tank 3 Printed Circuit Board 4 Electrode 5 Leaf Spring 6 Valve Means 7 Ink 8 Atmosphere Communication Port 13 Float 14 Ink Refilling Device 100 Control Circuit 111, 112 Signal Line Y Inkjet Unit

Claims (11)

[Claims] 1. An ink tank capable of containing ink therein, characterized by having a hole for refilling the inside of the ink and a detection means for detecting the amount of the ink contained therein. tank. 2. The ink tank according to claim 1, wherein the detection unit detects that the amount of the ink stored is the full filling amount. 3. The ink tank according to claim 1, wherein the detection means detects that the amount of the ink contained is a small amount that requires refilling. 4. The detection means has a pair of electrodes, and the electric resistance between the pair of electrodes changes in accordance with the amount of the ink contained therein. The ink tank described in Crab. 5. The detection means has a light emitting portion and a light receiving portion, and the light receiving amount of the light from the light receiving portion in the light receiving portion changes according to the amount of ink stored. The ink tank according to any one of claims 1 to 3. 6. The detecting means has a floating body that can float on the liquid surface of the ink, and detects the position of the floating body according to the amount of the ink contained. The ink tank according to any one of 1 to 3. 7. The ink tank according to claim 1, further comprising an output terminal for a detection signal of the detection means. 8. An ink jet unit comprising the ink tank according to claim 1 and an ink jet head to which the ink is supplied from the ink tank and which can eject the ink. . 9. The ink jet head according to claim 8, further comprising an electrothermal conversion element that generates heat energy that causes film boiling in the ink as energy used for ejecting the ink. The described inkjet unit. 10. The ink tank according to claim 1, an ink jet head to which the ink is supplied from the ink tank and which can eject the ink toward a print medium, and the ink jet head. An ink jet printer comprising: a moving unit that relatively moves the print medium. 11. The inkjet printer according to claim 10, further comprising display means capable of displaying a detection result of the detection means.