JP3058616B2 - Ink jet recording device - 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 apparatus, and more particularly, to a method for preventing ink from being clogged in a discharge port of a recording head and covering an ink discharge surface for initial filling of ink to suck ink and / or air. The present invention relates to an ink jet recording apparatus having an operable cap.

[0002]

2. Description of the Related Art In a recording head of an ink-jet recording apparatus, ink is ejected from a minute ejection port having a diameter of about 40 to 50 .mu.m to form flying droplets. Bubbles are likely to accumulate in the liquid path, and dust or ink that has adhered to the vicinity of or around the ejection port and solidifies the ink tends to cause non-ejection of the ink and irregular ejection of the recording material. Therefore, as shown in USP 4600931, in order to eliminate such a cause, a cap member is conventionally covered on the ejection surface of the recording head to cover the ejection port, including an operation of initially filling the liquid path with ink. A suction operation called a recovery operation has been performed, for example, when the user has been left without recording for a long time.

By the way, with respect to such a cap member, ink is ejected from ejection ports arranged on the ejection surface by suction means connected to the cap member side so as to cover the recording head led to the home position. FIG. 4 shows an example of a cap member used in a conventional discharge recovery device as shown in, for example, GB 2184061 A, which is configured to suck and discharge. Here, 1 is a cap member, and 2 is a recording head. In this example, the cap member 1 is mounted on the front plate 3 of the recording head 2. That is, in the recording head 2, a large number of ejection ports 4 are vertically arranged on the front plate 3, and the ink supplied to the liquid chamber 5 is guided from the liquid path 6 to the ejection ports 4. Ink can be ejected from the ejection port 4 by ejection energy generating means such as a piezo element or an electrothermal converter shown in the figure.

In the state where the cap member 1 is mounted on the front plate 3 of the recording head 2 as shown in FIG.
Silicone rubber provided on the periphery of the cap member 1,
The space 8 is formed by an elastic sealing member 7 such as butyl rubber.
Is kept airtight. Therefore, the air in the space 8 is sucked by the suction pump 10 from the communication port (suction port) 9 provided below the space 8 and communicated with the suction pump 10 to make the pressure (negative pressure) lower than the outside air. Thus, the ink can be guided to the space 8 through the discharge port 4, and the ink can be discharged from this to the waste liquid tank (not shown) by the suction pump 10.

In this type of conventional recovery device, a suction port 9 provided in the space 8 of the cap member 1 is disposed below the space 8, and the suction port is located at such a position. By providing the space 9, the undrawn portion of the ink guided to the space 8 is prevented from collecting, so that when the cap member 1 is separated from the recording head 2, the cap member 1 does not fall down and soil the apparatus.

[0006]

In the case of a conventional multi-nozzle recording head in which a large number of liquid paths and discharge ports are arrayed, for example, about 128, for example, hatching is applied to this drawing at the time of initial filling. As shown, before the liquid chamber 5 is completely filled with ink, ink is sucked from the lower one of the arranged discharge ports, and the upper liquid chamber and the liquid path are not filled with ink. In this state, the ejection recovery operation ends. Then, the next time the printing operation is started, the ink may not be ejected from the upper ejection port.

On the other hand, in a recording head of a full-line type recording apparatus which performs recording by discharging ink while keeping the recording head stationary on a recording medium, for example, about 17
Ninety-two discharge ports are arranged substantially in a line. In such a full-line type recording head, although the ejection port array is supported in a substantially horizontal direction, the distance between the ejection ports at both ends is large, and the length of the common liquid chamber communicating with each ejection port is also long. Become. Therefore, similarly to the above-described recording head, when the recording head is filled with the ink by the suction operation through the cap member to perform the ejection recovery, the above-described problem may occur. That is, when there is a communication port communicating with the suction pump at one end of the cap member, for example, non-discharge at the discharge port at the other end becomes a problem.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned conventional technical problems. The liquid paths at both ends are completely filled with ink through a liquid chamber, and ink suction is performed through all discharge ports. An object of the present invention is to provide an ink jet recording apparatus capable of performing a good ejection.

[0009]

According to the present invention, there is provided an ink jet recording apparatus, comprising: a cap member for covering a plurality of ejection openings for ejecting ink; and a cap member formed on the cap member. A space portion facing each of the plurality of discharge ports in a state in which the discharge ports are collectively covered, and the cap member along the arrangement direction of the plurality of discharge ports communicating with each other via the one space portion A plurality of communication portions provided at both ends of the plurality of communication portions and respectively communicating with the one space portion; and the plurality of communication portions communicating with the plurality of communication portions, wherein the cap member covers the plurality of discharge ports collectively. And suction means for sucking ink and / or air from the discharge port through the one space portion.

According to the present invention, the cap member collectively covers the plurality of ejection openings for ejecting ink, so that one space portion facing the plurality of ejection openings is formed in the cap member. At both ends of the cap member along the arrangement direction of the plurality of discharge ports that communicate with each other via the space, communication portions respectively communicating with the space are provided, and ink and ink interposed in the space are provided. The ink is sucked by the suction means through the communication portion, and the ink and / or air interposed in the plurality of ejection ports is also discharged from the space by the suction means through the communication portion.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In an ink jet recording apparatus according to the present invention, a plurality of discharge ports may be arranged vertically or horizontally. When arranged vertically, it is preferable to set the flow path resistance of the communication part located on the upper side to be smaller than the flow path resistance of the communication part located on the lower side.

Further, the plurality of communicating portions may be located at both ends of the cap member along the direction in which the plurality of discharge ports are arranged.

Further, an electrothermal converter for generating thermal energy used for discharging ink may be provided corresponding to each of the plurality of discharge ports.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an ink jet recording apparatus according to the present invention will be described in detail with reference to FIGS. 1 to 3. However, the present invention is not limited to such embodiments, and these may be further combined or similar. It can also be applied to technologies in other fields that include issues.

FIG. 1 shows a first embodiment of the present invention. Here, reference numeral 12 denotes a main suction port as a communication portion disposed at a position above the space portion 8 in the cap member 11;
Is a sub-suction port as a communicating part disposed below the space 8. In the case of this embodiment, both the main suction port 12 and the sub-suction port 13 communicating with the suction pump 14 via the communication pipe are provided. The main suction port 12 and its suction path 12A are made thicker than the sub suction port 13 and its sub suction path 13A. Here, the suction path 12A,
13A are made of the same material, and the suction passage 12A has a smaller flow resistance than the suction passage 13A due to the difference in cross-sectional area. In addition, the flow path resistance can be changed by changing the size of the suction port or making the surface rough.

Therefore, in the recovery device configured as described above, the front plate ejection surface of the recording head 2 guided to the home position when the common liquid chamber 5 and the liquid path 6 of the recording head 2 are initially filled. While the cap member 11 is kept covered with the cap 3A, the air in the space 8 is first sucked by the suction pump 14, and the discharge port 4
The ink is led out of the liquid chamber 5 and the liquid path 6 to the space 8 in the cap member 11 via the.

In the case of this embodiment, however, the ink is filled as shown in FIG. 4 during the suction process, and an unfilled portion is formed above the liquid chamber 5 and the space 8. Even if it remains, the air in this portion is continuously sucked by the suction pump 14 through the main suction port 12, so that the unfilled portion may be left closed as in the conventional example. As shown in FIG. 1, the space from the liquid chamber 5 to the discharge port 4 can be completely filled in a very short time without requiring a large suction force. Therefore, after this, the suction pump 1
4 is switched to the sub-suction path 13A to suck the ink, the ink remaining in the space 8 is discharged, and the cap member 11 can be removed from the recording head 2.

FIG. 2 shows a second embodiment of the present invention. In the present embodiment, the platen roller 1
01, the recording heads 121a, 121b, 121c and 121 corresponding to four colors of cyan, magenta, yellow and black are applied to the recording paper P sent to the recording position.
Recording is performed while d moves in the direction of arrow AA. These recording heads 121a to 121d are mounted on a carriage 102, guided along a guide shaft 103, and scan and move. 104 is a drive motor for driving the carriage 102, and 104A is its timing belt.

The ejection ports (not shown) of the recording heads 121a to 121d are covered with cap members 110 at the home positions, respectively, to perform ejection recovery. The structure relating to suction is basically the same as that of the first embodiment described above, except that the three-way ventilation valve 11 for communicating the space 8 inside the cap to the atmosphere in the middle of the communication passage.
It is equipped with 2. Thus, the cap moving means 1
11, the cap member 110 can be moved in the direction of arrow P to cover the ejection openings of the recording heads 121a to 121d.

Now, when a signal for performing a recovery operation in the recovery system configured as described above is input to the control circuit 105, the control circuit 105 switches the three-way ventilation valve 112 to the pump 11
3 is connected to the communication port 114 so that the pump 1
13 is driven to generate a pressure difference in the space 8, and the communication ports 114 and 115 provided in the cap member 110 are formed.
The ink and / or air is sucked from the discharge port through the nozzle.

Next, after a lapse of a predetermined time, the communication port 114
The three-way ventilation valve 112 is switched so that the atmosphere and the space 8 communicate with each other through the air, and the ink filling the space 8 of the cap member 110 is replaced with air, and the ink through the communication port 114 is exchanged. May be excluded from the inside of the cap member 110.

In this way, the discharge port can be kept in a good state, and the ink in the cap member 110 can be reliably removed. In the present embodiment, the ejection recovery operation corresponding to the recording head 121a has been described. However, the three-way ventilation valve 112 and the pump 113 may be provided for each color or may be the same for each color. Further, the recording head may be one that is integrally provided with an ink tank for accommodating ink and is detachably mounted on the carriage.

FIG. 3 shows a third embodiment of the present invention.
Reference numeral 12 denotes a recording head that performs recording on the recording medium P in a stationary state, and 201 denotes a roller that conveys the recording medium P.

At the time of non-recording, the cap member 210
The recording head 212 is configured to move in the direction and cover the ejection port 212A of the recording head 212. A suction pump 213 is connected to the cap member 210 via communication passages 214A and 215A provided at both ends of the cap member 210.
A space (not shown) in 10 communicates with the pump 213. One communication port 215 is provided at a position facing the left end discharge port in the figure, and the other communication port 214 is
It is provided at a position facing the right end ejection port.

In such a full-line type recording head, in order to minimize variations in the ink suction force of each ejection port and to perform an efficient ejection recovery (suction) operation, a suction generation source is used. It is preferable to provide caps communicating with a certain pump at a plurality of locations, more preferably at both ends.

In the above embodiment, a preferable recording head employs a method in which an image is formed by using an ink utilizing thermal energy to form ink droplets. An electrothermal converter for generation is provided corresponding to the discharge port. Such a recording head is preferably used because an electrothermal transducer for generating thermal energy is provided corresponding to each discharge port, and is easily formed into a multi-orifice.

[0027]

According to the ink jet recording apparatus of the present invention, when a plurality of ejection openings for ejecting ink are collectively covered by the cap member, one space facing the plurality of ejection openings is covered by the cap member. Formed from the plurality of communicating portions provided at both ends of the cap member along the arrangement direction of the plurality of ejection ports communicating with each other through the space portion, the ink in each ejection port through the space portion and Since the air is sucked by the suction means, the ink can be more appropriately filled, and the subsequent processing of the ink in the cap member is also facilitated.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of a configuration of a liquid jet recording head and an ejection recovery device thereof according to the present invention.

FIG. 2 is a perspective view showing a configuration of a second embodiment example of the present invention.

FIG. 3 is a perspective view showing the configuration of a third embodiment of the present invention.

FIG. 4 is a schematic view showing an example of the configuration of a conventional ink jet recording head and its ejection recovery device.

[Explanation of symbols]

 2, 121a to 121d, 212 Recording head 4, 212A Discharge port 5 Liquid chamber 6 Liquid path 8 Space section 11, 110, 210 Cap member 12 Main suction port 13 Sub suction port 14, 113, 213 Suction pump 12A, 13A Suction path 114, 115, 214, 215 Communication port 214A, 215A Communication path

Claims (5)

(57) [Claims] 1. A and rainy cap member covering collectively a plurality of discharge ports for discharging ink, a space formed to the cap member, the key
In a state where the cap member covers the plurality of discharge ports at once.
The plurality of discharge ports are mutually connected through the space.
A plurality of communication portions provided at both ends of the cap member along the arrangement direction of the plurality of discharge ports which communicate with each other through the space portion, and the plurality of communication portions respectively communicate with the space portion; A suction port that communicates with the plurality of communication sections and suctions ink and / or air from the plurality of discharge ports via the space portion in a state where the cap member covers the plurality of discharge ports in a lump; And an ink jet recording apparatus. 2. The ink jet recording apparatus according to claim 1, wherein the plurality of discharge ports are arranged in a vertical direction. 3. The flow path resistance of the communication portion located on the upper side.
Is smaller than the flow path resistance of the communication portion located on the lower side.
3. The input device according to claim 2, wherein
Jet recording device. 4. The ink jet recording apparatus according to claim 1, wherein the plurality of ejection ports are arranged in a horizontal direction. 5. An electrothermal converter for generating thermal energy used for discharging ink is provided corresponding to each of the plurality of discharge ports. Item 6. An ink jet recording apparatus according to any one of items 4 .