JP2772014B2 - Recording liquid supply mechanism - Google Patents

Description

The present invention relates to a recording liquid supply mechanism.

[Prior Art] FIG. 6 shows a first recording liquid storage member having a conventional recording liquid absorber impregnated with a recording liquid, a recording liquid supplied from the storage member, and supplied to a recording medium. FIG. 7 (a) is a view of the main body of an ink jet recording apparatus which mounts on a carriage in a state where it is connected to a discharge section which performs recording by discharging, and performs recording while moving the carriage relatively to the recording medium. 3A and 3B show a perspective view and a sectional view of the ink tank / head integrated cartridge, respectively.

Here, reference numeral 100 denotes a recording head chip, which includes a discharge unit 102, a supply tank unit 104, and the like. The discharge unit 102 includes a discharge port 102A formed on a surface facing the recording medium, a liquid path extending inward, a discharge energy generating element such as an electrothermal converter disposed in each liquid path, and A common liquid chamber communicating with the liquid path. Further, the supply tank unit 104 functions as a sub-tank that receives supply of ink from the ink tank 110 side and guides the ink to a common liquid chamber in the ejection unit 102.

Reference numeral 112 denotes an ink absorber provided in the ink tank 110 and impregnated with ink, and can be formed using a porous body or a fiber. Reference numeral 114 denotes a lid member of the ink tank 110.

An ink jet printer as shown in FIG. 6 using the ink jet recording head having the above configuration, that is,
An ink jet printer using a recording head in the form of a disposable cartridge can be configured.

In FIG. 6, reference numeral 14 denotes FIGS. 7 (a) and (b).
The recording head 14 is fixed on the carriage 15 by a pressing member 41, and these can be reciprocated in the longitudinal direction along the shaft 21. The positioning with respect to the carriage 15 can be performed by, for example, a hole provided in the recording head chip 100 and a dowel provided on the carriage 15 side. Further, for electrical connection, a connector on the carriage 15 may be connected to a connection pad provided on the wiring board for the ejection unit 102.

The ink discharged by the recording head reaches the recording medium 18 whose recording surface is regulated by the platen 19 at a minute interval from the recording head, and forms an image on the recording medium 18.

An ejection signal corresponding to image data is supplied to the recording head from a data source as appropriate via a cable 16 and a terminal connected thereto. One or more (two in the figure) cartridges 14 can be provided according to the ink color or the like to be used.

In FIG. 6, reference numeral 17 denotes a carriage
A carriage motor for scanning along 21 and a wire 22 for transmitting the driving force of the motor 17 to the carriage 15. Reference numeral 20 denotes a recording medium connected to a platen roller 19.
Is a feed motor for transporting the paper.

With the above-described configuration, a disposable type in which a so-called permanent head type ink jet recording apparatus in which a permanent recording head and an ink tank are used in a state of being connected by a connecting means such as a tube or the like has been improved in reliability (foam mixing, etc.). An ink jet recording apparatus (a disposable head type ink jet printer) using the ink tank integrated cartridge described above.

[Problems to be Solved by the Invention] However, such a conventional disposable head type ink jet printer has the following three major problems.

1. If the capacity of the ink tank is increased to reduce the running cost, the volume of the ink tank occupying the carriage is increased, which results in an increase in the size of the printer body and an increase in cost. In addition, since the load on the carriage drive motor is increased by the weight of the increased ink, a motor capable of outputting high torque is required, and the cost of the motor is increased. That is, if the capacity of the ink tank is increased to reduce the running cost, there is a problem that the cost of the main body is greatly increased.

2. If the ink absorbing capacity of the absorber is increased to reduce the running cost, the printer body does not increase in size, and only the cost of the carriage drive motor as described above increases. However, as the ink absorbing ability of the ink absorber is larger, the change in the water head pressure due to the change in the remaining amount of ink is larger, and the effect that the ejection characteristics are changed by the remaining amount of ink is larger, so that stable printing quality can be maintained. There was a problem that it disappeared. The change in the ejection characteristics due to the change in the remaining amount of ink can be explained as follows.

When the ink tank containing the ink absorber is connected to the recording head, negative pressure due to the capillary absorption of the absorber is applied to the ink in the head, and this negative pressure and the pressure due to the capillary absorption of the ink flow path. As a result, the meniscus is formed, and the remaining amount of ink changes. That is,
When the volume of the absorber having the ability to absorb ink changes, the negative pressure changes, so that the water head pressure changes. FIG. 8 shows the relationship between the remaining amount of ink and the head pressure. From the figure, it can be seen that the water head pressure decreases as the remaining amount of ink decreases. In the figure, b is a curve in the case of using an absorbent having a larger absorptivity than a, and it can also be seen that the higher the absorptivity, the larger the change in water head pressure.

FIG. 9 shows the relationship between the head pressure and the ink ejection amount. As the water head pressure decreases, the ink ejection amount gradually decreases. When the water head pressure further decreases, the ink discharge amount sharply decreases, and finally, the ink ejection stops. This is because, as the head pressure decreases, the negative pressure increases, the force for pulling ink toward the ink tank increases, and the discharge pressure decreases. The amount is reduced. When the water head pressure further decreases, the force of capillary absorption of the ink nozzle and the negative pressure become approximately the same, so that it becomes difficult for the ink to flow into the ink nozzle after the ink is ejected, the ink nofill time becomes longer, and At the driving frequency, the refill cannot be performed in time, so that the ink ejection amount sharply decreases, and finally the ink is not ejected even though the ink remains. FIG. 10 shows the relationship between the head pressure and the appropriate refill frequency.

For such a reason, in an ink jet recording apparatus that uses an ink tank containing an ink absorber and a recording head in connection with each other, it is considered that the ink ejection amount changes depending on the remaining amount of ink in the ink tank.

3. In addition, a so-called pit-in type permanent head type ink jet recording apparatus which separates an ink tank and a recording head and replenishes the recording head with ink from the ink tank at a predetermined time is known. Practicality was low due to mixing of bubbles.

The present invention has been made in view of the above problems, and provides a recording liquid replenishing mechanism that can stably inject recording liquid by preventing air bubbles from being mixed into a storage member that stores the recording liquid, and that can prevent leakage of the recording liquid. Is what you do.

[Means for Solving the Problems] According to the present invention, the recording liquid absorbing member is impregnated with the recording liquid and accommodated therein, and the recording liquid supply member having the recording liquid supply opening is provided with the recording liquid supply member. In a recording liquid replenishment mechanism for replenishing recording liquid through an opening, a flexible resin recording liquid container for storing the recording liquid, and a supply for supplying ink in the recording liquid container to the recording liquid storage member Having a porous body provided in the supply pipe for holding ink, wherein the recording liquid container is pressed while the opening of the recording liquid storage member and the supply pipe are joined to each other. By allowing the recording liquid to be replenished to the recording liquid storage member, unlike a conventional disposable type ink tank integrated cartridge,
The printing operation can be easily performed continuously without increasing the cartridge size, increasing the absorbency of the recording liquid absorber, increasing the body size, increasing the cost, and increasing the carriage drive motor torque. Since the ejection characteristics of the ink jet recording device can be stabilized, a highly reliable ink jet recording apparatus can be obtained.

The inkjet recording apparatus of the present invention includes a first recording liquid storage member (hereinafter abbreviated as a first ink tank) and a recording liquid replenishment mechanism (hereinafter referred to as an ink replenishment mechanism) for replenishing the first recording liquid storage member with a recording liquid (hereinafter abbreviated as ink). (Abbreviation). The supply mechanism basically includes a first ink tank, an ink supply hole, and a second recording liquid storage member (hereinafter, abbreviated as a second ink tank).
The ink supply hole is provided on a first ink tank mounted on the carriage, and the supply hole is connected to a second ink tank not mounted on the carriage and has a shape capable of being inserted and removed. have. That is, the ink to be supplied is supplied from the second ink tank through the ink supply hole into the first ink tank.

The second ink tank is not mounted on the carriage, but may not be incorporated in the ink jet recording apparatus main body, and may be a single container that can be handled independently.
It may be incorporated in the device body.

The ink supply hole may have any shape and structure that can effectively supply the ink from the second ink tank to the ink absorber in the first ink tank. Usually, the upper surface of the first ink tank, Therefore, the holes may be simply provided at positions where the ink does not leak, and the holes may be simply provided, or folds for preventing leakage from the holes may be provided. The second ink tank has a connection pipe that can be connected to the ink supply hole, and the connection pipe is normally inserted into the first ink tank through the supply hole.

In the present invention, the remaining amount detecting means provided in the ink absorber may basically be a device for detecting the remaining amount by resistance between the electrodes, and may be constituted by, for example, a set of pin electrodes. . The electrode may be installed at any position where the remaining amount can be detected best. If one of the electrodes is a mesh electrode provided so as to cover the inside of the connection portion head side in the first ink tank (the port from which the ink is ejected from the ink absorber to the recording head chip), it is assumed that a mesh electrode is provided. Also, it is preferable because it also serves as a filter for preventing foam mixing.

The detecting means can not only display the replenishment time but also display the full point during supply. The display means can be visually recognized or the like by converting it into an optical signal or a sound signal and outputting it. Further, an automatically operated valve is provided in a connection pipe section from the second ink tank, the detection means is electrically connected to the valve, and a signal from the detection means is directly sent to the valve to automatically supply ink. (Automatic ink supply mechanism).

The timing of supplying the ink to the first ink tank is when the amount of the ink is reduced to such an extent that the refill can be performed appropriately. However, when the automatic ink replenishment mechanism is used, the ink head pressure in the ink absorber is reduced. Can be controlled so that is within a certain range. The ink supply timing may be set as appropriate depending on the usage of the ink jet recording apparatus, the form of the second ink tank, the ink supply means, and the like.

In addition to the configuration described above, a known structure, mechanism, ink, or the like used in an inkjet recording apparatus can be used.

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples.

Embodiment 1 Next, an embodiment of the present invention in which ink supply is performed manually will be described.

A first ink tank having a configuration as shown in FIG. 1 is set in a conventional disposable head type ink jet printer as shown in FIG. 6 in place of a conventional ink tank to constitute an ink jet recording apparatus of the present invention. A second ink tank joining portion 113 is provided on the upper surface of the first ink tank as an ink supply hole, and a fold is attached to the joining portion. One set of pin electrodes for detecting the remaining amount in the absorber is fixed at the positions shown in the figure. The second ink tank for replenishing the ink is substantially the same size as the first ink tank and has a configuration as shown in FIG. 2, and includes a flexible resin ink container and pressure bag 202 and an insertion tube 201, An ink holding absorber 203 is fixed to the insertion tube 201 so as to seal the tube. The ink holding absorber is effective for preventing ink leakage when the ink tank vibrates and preventing air bubbles from entering when ink is injected.

 The ink was replenished as follows.

Remaining amount detecting means: A set of remaining amount detecting pin electrodes is provided in the absorber to detect interelectrode resistance. Replenishment time: An empty warning signal is displayed on the main body or a sound is generated by detecting the remaining amount. Filling the absorber from the ink tank and replenishing it. When replenishment is stopped: A full warning signal is displayed on the main unit or a sound is generated due to the detection of the remaining amount. FIG. When the ink is full, the resistance value is small and the resistance value increases as the remaining amount decreases.Therefore, when the resistance value corresponding to the replenishment time is reached, and when the replenishment is carried out and it is full, the resistance value has become the minimum. Sometimes the electrical signal system is set to issue an empty warning and a full signal respectively.

 The supply procedure is as follows.

Blank warning display Stop printing, return to home position User opens lid of main unit, inserts second ink tank into first ink tank Inserts pressurized bag of second ink tank with finger into first ink tank When the filling full warning is displayed, the ink filling may be stopped. Alternatively, a plurality of second ink tanks may be prepared and inserted into the first ink tank sequentially to perform the ink filling.

According to the embodiment described above, ink can be easily supplied regardless of the size of the main body of the ink jet printer and the size of the ink tank.

Embodiment 2 Next, an embodiment of the present invention in which ink supply is performed automatically will be described. In this case, an ink replenishment mechanism is configured by detecting the remaining amount of ink in the first ink tank as a change in water head pressure.

3A and 3B show the configuration of a first ink tank used. An ink supply window 11 is provided on the upper surface of the first ink tank.
5 are provided. In addition, as an electrode for detecting the remaining amount in the absorber, a pin electrode 111 is used on one side, and a mesh electrode 116 provided on the connection part head side is used on the other side. The mesh electrode is fixed so as to cover the ink outlet, and a foam filter is provided. It has an effective effect and also has a foam mixing prevention effect. FIG. 12 shows the relationship between the resistance between the remaining amount detection electrodes and the head pressure. Thus, the water head pressure fluctuation warning point C and the ink replenishment stop point B can be set within a desired water head pressure range by the resistance value.

The configuration of the replenishing device incorporated in the ink jet recording apparatus main body is as shown in FIG.
(Two A and B) are installed at a position higher than the first ink tank, and are connected to the first ink tank by a connection pipe 26. In the middle of the connection pipe 26, the mechanical valve device 24
The mechanical valve device is operable to receive an electric signal from the remaining amount detection electrode. The mechanical valve device has a mechanism for closing and opening the connection pipe 26 by rotating the cam 27 as shown in FIG. The operation of the cam by the signal from the electrode is set so that the head pressure is always within a substantially constant range.

 Automatic replenishment is performed as follows.

Water head pressure detecting means (also used as remaining amount detecting means): A mesh electrode is provided to cover the remaining amount detecting pin and the connecting part in the absorber, and the resistance value between the electrodes is detected. Replenishment timing: When the water head pressure exceeds a predetermined value If the replenishment method stops, the water head pressure becomes higher than a predetermined value. Replenishment method: Automatic replenishment from the second ink tank higher than the first ink tank through a mechanical valve (second tank> first tank) Automatically discontinued if it does The automatic replenishment procedure is as follows.

The remaining pressure detection electrode detects the head pressure fluctuation warning point. Stops printing and returns to the home position. The cam of the mechanical valve rotates, the tube (connection tube) connected to the ink tank that received the warning is opened, and ink is released. Replenishment from the second ink tank to the first ink tank The tube is closed and replenishment is stopped by the mechanical valve whose remaining amount detection electrode detects the replenishment stop point. According to the above-described embodiment, the first ink tank of the carriage Can be made smaller, so the carriage can be smaller,
Since the load on the carriage drive motor can be reduced, loss and down can be prevented. In addition, since the mesh electrode plays a role of a bubble mixing prevention filter, instability of the ink discharge amount due to bubble mixing can be prevented, and reliability is improved. be able to. Further, since the head pressure can always be controlled within a certain range, there is an effect that the ink ejection amount is stabilized and the print quality is stabilized.

In the above configuration, the ink supply is performed until the remaining amount detection electrode detects the point beyond the ink full point, and then the ink suction is performed until the remaining amount detection electrode detects the ink supply stop point and then stopped. A replenishment sequence may be used. In this case, the precision of the mechanical valve is not so required, so that the cost can be reduced.

Further, the ink supply position may be provided at the turn-back position of the carriage, and the ink supply may be performed during the printing operation. In this case, the ink supply can be performed without interrupting the printing, so that the sleep of the image can be increased.

[Effects of the Invention] As described above, according to the present invention, the recording liquid is stably prevented from being introduced into the recording liquid storage member having the recording liquid supply opening by accommodating the recording liquid. And a recording liquid replenishing mechanism capable of preventing leakage of the recording liquid due to vibration.

According to the recording liquid supply mechanism of the present invention, the ink jet recording apparatus using the recording liquid storage member does not involve an increase in the size and cost of the main body, an increase in the torque of the carriage drive motor, and a stable state. Can be used to supply ink.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view (partially transparent view) showing the configuration of the first ink tank head integrated type cartridge used in the first embodiment, and FIG. 2 shows the configuration of the second ink tank used in the first embodiment. FIG. 3 is a schematic perspective view (perspective view), and FIG. 3 is a schematic view showing a configuration of a first ink tank head integrated type cartridge used in Embodiment 2.
(A) is a partially transparent perspective view, (b) is a cross-sectional view, FIG. 4 is a schematic diagram (partially omitted) showing the configuration of the ink jet recording apparatus used in Example 2, and FIG. 5 is a mechanical diagram in FIG. FIG. 6 is a schematic perspective view showing a configuration of a conventional disposable head type ink jet printer main body, and FIG. 7 is a schematic view showing a configuration of a conventional disposable type ink tank integrated cartridge. FIG. 8 (a) is a partially perspective view, FIG. 8 (b) is a cross-sectional view, and FIG. 8 is a diagram showing the relationship between the remaining amount of ink and the head pressure in a conventional disposable type ink tank (b is a
FIG. 9 is a diagram showing the relationship between the water head pressure and the ink ejection amount in the same ink tank as in FIG. 8, and FIG. 10 is a diagram showing the relationship between the ink discharge amount and the ink in the same ink tank as in FIG. FIG. 11 is a diagram showing a relationship between a water head pressure and a refill frequency. FIG. 12 is a diagram showing the relationship between the inter-electrode resistance of the remaining amount detection electrode (residual detection electrode) used in Example 2 and the head pressure. 14 Printhead, 15 Carriage 16 Cable, 17 Carriage motor 18 Recording medium 19 Platen 20 Feed motor 21 Shaft 22, Wire 23 Second ink Tank A (with B not shown) 24 Mechanical valve device 25 Supply station (movable when replacing cartridge) 26 Connection pipe 27 Cam 28 Ink 41 Pressing member 100 … Print head chip 102… discharge section, 102A… discharge port 104… supply tank section, 110… ink tank (recording liquid storage member) 111… remaining ink level detection electrode pin 112… ink absorber 113 ... Second ink tank joint (opening) 114... Lid member 115... Ink supply window 116... Mesh electrode 200... Second ink tank (recording liquid supply mechanism) 201.
Insertion tube (supply tube) 202: Ink container and pressurized bag 203: Ink absorber (porous material) A: Ink full point (Initial) B: Ink full stop point C: Fluctuation in head pressure Warning point

Continued on the front page (72) Inventor Norifumi Kotabashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Masami Ikeda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-62-273856 (JP, A) JP-A-63-41147 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41J 2/175

Claims (1)

(57) [Claims] A recording liquid is impregnated and contained in a recording liquid absorber contained therein, and a recording liquid is supplied to a recording liquid storage member having a recording liquid supply opening through the recording liquid supply opening. A recording liquid supply mechanism for storing the recording liquid, a flexible resinous recording liquid container, a supply pipe for supplying ink in the recording liquid container to the recording liquid storage member, and a supply pipe provided in the supply pipe. The recording liquid container is pressed by the recording liquid container being pressed in a state where the opening of the recording liquid storage member and the supply pipe are joined to each other. A recording liquid replenishing mechanism, which is capable of replenishing the recording liquid to the recording medium.