JPH0976523A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To replace a liquid such as ink charged in a printing head with a liquid such as other ink in an ink jet recording apparatus. SOLUTION: An ink jet recording apparatus has a plurality of liquid tanks 40, 45 housing a liquid, a changeover means 54 alternatively connecting a plurality of the liquid tanks 40, 45 to a first liquid communication part 51, a discharge means discharging the liquid housed in a printing head 13 to the outside from a second liquid communication part 52, a first filling means filling a common liquid chamber 31 with the liquid of the liquid tanks 40, 45 from the first liquid communication part 51 and a second filling means filling nozzles 23 with the liquid of the common liquid chamber 31 charged by the first filling means from the common liquid chamber 31.

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 specifically, an ink jet system capable of replacing a liquid material such as ink filled in a print head with a liquid material such as another ink. Recording device

[0002]

2. Description of the Related Art An ink jet recording apparatus is one in which ink droplets are ejected from nozzles of a print head to print on recording paper or the like. This print head has, for example, a large number of nozzles 13 on one surface, as shown in the sectional view of the main part shown in FIG.
The nozzles 130 are arranged in an array, and each nozzle 130 is connected to the common liquid chamber 132 via the pressure chamber 131 on the upstream side. A piezoelectric element 133 is arranged outside the pressurizing chamber 131, and a first liquid communicating portion 134 and a second liquid communicating portion 135 communicating with the outside are formed at both ends of the common liquid chamber 132.

The ink filling (so-called initial filling) into the print head having the above-described structure is performed by the first liquid communicating portion 13.
The ink tank 137 is connected to the external flow path 136 provided on the nozzle No. 4, and the capillarity phenomenon that occurs in the nozzle 130, the common liquid chamber 132, or the like is used. The print head filled with ink is supplied with a drive signal and is supplied with the piezoelectric element 13.
When 3 is driven, a vibrating plate (not shown) forming a part of the pressurizing chamber 131 vibrates, so that the pressurizing chamber 1
31 is pressed, whereby ink droplets are ejected from the nozzles 130 and predetermined printing is performed on recording paper or the like.

[0004]

However, since the ink is filled in the print head by utilizing the capillary phenomenon that occurs in the nozzle 130, the common liquid chamber 132, etc., as described above, it is more than necessary. Will take time.
Further, since the nozzle 130 has an extremely small diameter, it takes more time to discharge the ink once filled in the print head to the outside. Therefore, once the print head is filled with ink, it is extremely difficult to replace the ink with another liquid such as ink.

Therefore, for example, it is extremely convenient if the ink suitable for printing on the recording paper and the ink suitable for printing on the synthetic resin sheet for OHP are replaced with each other. In the past, such an ink jet recording device did not exist.

Accordingly, it is an object of the present invention to provide an ink jet recording apparatus capable of replacing a liquid material such as ink filled in a print head with a liquid material such as another ink.

[0007]

In order to achieve such an object, an ink jet recording apparatus according to a first aspect,
A large number of nozzles are formed in an array on one surface, each nozzle is communicated with a common liquid chamber via a pressurizing chamber, and both ends of the common liquid chamber have first and second liquid communicating portions communicating with the outside. A liquid head filled with the formed print head can be replaced with another liquid body, and a plurality of liquid tanks containing the liquid body, and Switching means for selectively connecting a plurality of liquid tanks to the first liquid communication portion side, and discharging means for discharging the liquid material filled in the print head to the outside from the second liquid communication portion side. A first filling means for filling the liquid material in the liquid tank into the common liquid chamber from the first liquid communicating portion side; and a liquid material in the common liquid chamber filled by the first filling means for the common liquid chamber. Second filling means for filling the nozzle from the side It is.

In the ink jet recording apparatus according to the first aspect, the liquid material filled in the print head is discharged to the outside from the second liquid communicating portion side by the discharging means, and the predetermined liquid tank is discharged by the first filling means. The liquid material is drawn from the first liquid communication portion and filled in the common liquid chamber. The liquid material filled in the common liquid chamber is caused to flow from the common liquid chamber to the nozzle side by the second filling means and is filled in the nozzle.
The liquid material remaining in the nozzle is discharged from the nozzle surface side when a new liquid material is poured into the nozzle, and as a result, the print head is filled with the new liquid material.

An ink jet recording apparatus according to a second aspect of the present invention is the ink jet recording apparatus according to the first aspect, wherein the control means for controlling the operation of each of the means and the print head are relatively moved to move the nozzle surface. An airtight covering cap is provided, the switching means is a flow path selection valve connected to the flow path on the side of the first liquid communication portion, and the discharging means and the first filling means are the second The first suction pump connected to the flow path on the liquid communication part side of the second filling means, the second filling means is composed of the cap and the second suction pump connected to the cap, and the control means is The liquid material filled in the print head by operating the flow path selection valve to connect a predetermined liquid tank to the flow path on the side of the first liquid communication unit and operating the first suction pump. From the second liquid communication part side to the outside The liquid material in the liquid tank is discharged and drawn into the print head from the first liquid communication portion side to fill the common liquid chamber, and thereafter, the operation of the first suction pump is stopped and the nozzle surface is The second suction pump is operated with the cap covered with the cap in an airtight manner, whereby the liquid material filled in the common liquid chamber is poured from the common liquid chamber to fill the nozzle.

In the ink jet recording apparatus according to the second aspect of the present invention, the liquid tank connected to the flow path on the side of the first liquid communication portion is switched by the first flow path selection valve so that a predetermined liquid material is stored in the print head. Be made available. In this state,
The first suction pump connected to the flow path on the second liquid communication section side discharges the liquid material filled in the print head from the second liquid connection section side to the outside, and at the same time, the first liquid communication section. Liquid from the liquid tank is drawn into the print head from the
The common liquid chamber is filled. The liquid filled in the common liquid chamber is flown from the common liquid chamber to the nozzle side when the air in the cap that covers the nozzle surface in an airtight manner is sucked by the second suction pump to the nozzle. Is filled. The liquid remaining in the nozzle is discharged from the nozzle surface side by filling the nozzle with a new liquid.
As a result, the print head is filled with new liquid material.

The ink jet recording apparatus according to a third aspect is the ink jet recording apparatus according to the second aspect, wherein the control means operates the first suction pump in a state where the nozzle surface is covered with the cap in an airtight manner. As a result, the liquid material filled in the print head is discharged to the outside from the second liquid communication portion side, and the liquid material in the liquid tank is drawn into the print head from the first liquid communication portion side to be common. It is characterized by filling the liquid chamber.

In the ink jet recording apparatus according to the third aspect of the present invention, since the first suction pump is operated with the nozzle surface covered in an airtight manner, excess air is not sucked from the nozzle surface side, resulting in printing. The liquid material filled in the head is reliably discharged from the second liquid communication portion side to the outside, and the liquid material in the liquid tank is reliably filled in the common liquid chamber.

An ink jet recording apparatus according to a fourth aspect is the ink jet recording apparatus according to the first aspect, wherein a control means for controlling the operation of each of the means is provided, and the switching means is on the side of the first liquid communication section. A flow path selection valve connected to the flow path and capable of closing the flow path without being connected to any of the liquid tanks. A pump capable of forward and reverse driving is connected to the flow path, the discharging means and the first filling means are the pumps that are driven forward, and the second filling means is the pump that is driven in reverse. Activates the flow path selection valve to connect a predetermined liquid tank to the flow path on the side of the first liquid communication unit, and positively drives the pump, thereby removing the liquid material filled in the print head. From the second liquid communication part side to the outside The liquid material in the predetermined liquid tank is drawn out from the first liquid communication portion side into the print head to fill the common liquid chamber, and then the flow path selection valve is operated to operate the first liquid communication portion side. The flow path is closed and the pump is reversely driven so that the liquid material filled in the common liquid chamber is caused to flow into the common liquid chamber to fill the nozzle.

In the ink jet recording apparatus according to the present invention, the liquid tank connected to the flow path on the side of the first liquid communication portion is switched by the first flow path selection valve so that the predetermined liquid material is stored in the print head. Be made available. In this state,
The forward and reverse drivable pump connected to the flow path on the side of the second liquid communication unit is driven forward, so that the liquid material filled in the print head is discharged to the outside from the side of the second liquid connection unit. At the same time, the liquid material in the liquid tank is drawn into the print head from the first liquid communication portion side, and is filled in the common liquid chamber. The liquid filled in the common liquid chamber is poured from the common liquid chamber to the nozzle side by the reverse drive of the pump capable of forward and reverse driving, and is filled in the nozzle. The liquid remaining in the nozzle is discharged from the nozzle surface side by filling the nozzle with the new liquid, and as a result, the print head is filled with the new liquid.

An ink jet recording apparatus according to a fifth aspect of the present invention is the ink jet recording apparatus according to the fourth aspect, further comprising a cap that moves relative to the print head to cover the nozzle surface in an airtight manner, and the control means. Is a positive drive of the pump in a state where the nozzle surface is covered with a cap in an airtight manner,
As a result, the liquid material filled in the print head is discharged from the second liquid communication portion side to the outside, and the liquid material in the liquid tank is drawn into the print head from the first liquid communication portion side so that the common liquid chamber It is characterized by filling in.

In the ink jet recording apparatus according to the fifth aspect of the present invention, since the pump is normally driven while the nozzle surface is airtightly covered, excess air is not sucked from the nozzle surface side, and as a result, the print head is filled. The liquid material is surely discharged to the outside from the second liquid communication portion side, and the common liquid chamber is reliably filled with the liquid material in the liquid tank.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an ink jet recording apparatus according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a front view of an ink jet recording apparatus. In this figure, the inkjet recording device is
Paper transport unit 1, printing unit 2, capping unit 3, paper feeding unit 4
And a paper discharge section 5.

The sheet conveying section 1 is constructed by a pair of belt rollers 8 and 9 which are coupled to the supporting shafts 6 and 7 and which are arranged to face each other, and a conveying belt 10 is stretched over the supporting shaft. The conveyor belt 10 is adapted to rotate in the direction of the arrow by the rotational drive of the drive motor 11 engaging with 6. The sheet transport unit 1 transports a recording sheet, which will be described later, placed on the transport belt 10 from the right side to the left side in the drawing, that is, from the upstream side to the downstream side. The support shafts 6 and 7
Are rotatably supported by a pair of support plates (not shown) that are arranged to face each other.

The printing unit 2 is provided with four color print heads 13, 14, 15 and 16 of black, cyan, magenta and yellow, which are arranged on the upper part of the paper transport unit 1, and the vicinity of the central portion thereof. In the above, it is integrally supported by the support body 17. A support portion 19 having a through hole 18 formed of a female screw is integrally formed on the support body 17,
The drive shaft 2 made of a male screw is inserted into the through hole 18 of the support portion 19.
0 is penetrated.

One end of the drive shaft 20 is directly connected to a drive motor 21 fixed to a support plate (not shown), and the other end is rotatably supported by a support plate (not shown).
When the drive motor 21 is rotationally driven, the drive shaft 20 rotates and the print heads 13, 14, 15, 16 move in the vertical direction with respect to the paper transport unit 1. The support portion 19
A support shaft, which is arranged in parallel with the drive shaft 20 and also serves as a guide (not shown), penetrates through so that the rotation of the drive shaft 20 prevents the print heads 13, 14, 15, 16 from rotating together. There is.

The print heads 13 and 1 of the printing unit 2 are also
The nozzles 4, 24, 25 and 26 of the nozzles 4, 24, 25 and 26 are arranged in an array on the surface facing the sheet conveying section 1 and the nozzles 23, 24, 25 and 26 are added to the upper portion of the nozzles 23, 24, 25 and 26, respectively. The pressure chambers 27, 28, 29 and 30 are communicated with the common liquid chambers 31, 32, 33 and 34, respectively.
Piezoelectric elements 35, 36, 3 are provided outside 7, 28, 29, 30.
7, 38 are attached and configured. The print heads 13, 14, 15, 16 configured in this way are
Drive signals are applied to the piezoelectric elements 35, 36, 37, 38.
When driven, the vibrating plate (not shown) forming a part of the pressurizing chambers 27, 28, 29, 30 vibrates and the pressurizing chambers 2
A recording medium, such as a recording sheet, which pressurizes the ink inside 7, 28, 29, 30 and thereby ejects ink droplets from the nozzles 23, 24, 25, 26 to the outside and is fed onto the sheet conveying unit 1. Perform predetermined printing on.

Further, the print heads 13, 14, 15,
For example, when the recording medium is a recording sheet, reference numeral 16 is approximately the paper width whose width (in the figure, the direction that penetrates the sheet surface) is a direction orthogonal to the transport direction of the recording sheet fed onto the sheet transport unit 1. Print heads 13, 14, 15,
Printing is performed within the paper width of the recording paper while 16 is fixed, and printing is performed on the entire paper surface by moving the recording paper from the upstream side to the downstream side.

In the lower part of the paper transport unit 1, for example, a first ink cartridge 44 having liquid tanks 40, 41, 42, 43 storing four color inks suitable for printing on recording paper, for example, Liquid tanks 45 and 46 storing four color inks suitable for printing on a synthetic resin sheet for OHP,
A second ink cartridge 49 having 47 and 48 is arranged in two stages, an ink of each color is supplied to each of the print heads 13, 14, 15 and 16 through an external flow path formed of a pipe. ing. The connection of the first and second ink cartridges 44, 45 to the print heads 13, 14, 15, 16 can be switched for each cartridge unit. These print heads 13, 14,
Specifically, the ink is supplied to the inks 15 and 16 by the configuration shown in FIG.

FIG. 2 is an enlarged cross-sectional view taken along the line AA of the print head 13 shown in FIG. 1, in which the liquid tank 40 of the first ink cartridge 44, the liquid tank 45 of the second ink cartridge 49, etc. are shown. For convenience, it is shown in a position different from that in FIG. In FIG. 2, both ends of the common liquid chamber 31 of the print head 13 have a first liquid communicating portion 51 communicating with the outside.
And a second liquid communication part 52 are formed, and the first liquid communication part 51 is provided with a first external flow path 53 made of a pipe. The first external flow path 53 is an example of a switching means. Is connected to the first flow path selection valve 54. The liquid tank 40 is connected to the flow path selection valve 54 via the first connection flow path 55, and the liquid tank 45 is connected to the flow path selection valve 54 via the second connection flow path 56. The first flow path selection valve 54 is electromagnetically operated to selectively connect the liquid tank 40 or the liquid tank 45 to the first external flow path 53.

Further, a second external flow passage 57 made of a pipe is connected to the second liquid communication portion 52, and a second flow passage selection as an example of a switching means is connected to the second external flow passage 57. A valve 59 is connected, and a first suction pump 60 is connected between the second flow path selection valve 59 and the second liquid communication section 52.

The print heads 13, 14, 15, 1 are connected to the second flow path selection valve 59 via the third connection flow path 61.
The waste liquid tank 62 shared by 6 is connected, the liquid tank 40 is connected through the fourth connection flow path 63, and the liquid tank 45 is connected through the fifth connection flow path 64. However, the liquid tank side of the fourth connection flow channel 63 and the fifth connection flow channel 64 is connected to a location where ink liquid does not exist. The second flow path selection valve 59 is electromagnetically operated to selectively connect the waste liquid tank 62, the liquid tank 40 or the liquid tank 45 to the second external flow path 57. . As shown in FIG. 1, the waste liquid tank 62 is arranged in the lower part of the paper transport unit 1 side by side with the first and second ink cartridges 44 and 49. Although FIG. 2 shows the print head 13, the other print heads 1
The print heads 4, 5, and 16 have the same structure as the print head 13. Therefore, in the following description, for the sake of convenience, the components shown only in FIG.
The same reference numerals are given to the print heads other than the print head 13.

The capping unit 3 includes the nozzles 23, 2 of the print heads 13, 14, 15, 16 which form the printing unit 2.
The caps 70, 71, 72, and 73 are sized to fit in airtight manner with the surfaces 4, 25, and 26, respectively. These caps 70, 71, 72, 73 are arranged on the downstream side of the paper transport unit 1, which is the home position thereof. Through holes 74, 75, 76, 77 are formed on the inner bottom surfaces of the caps 70, 71, 72, 73, respectively. Each of these through holes 74, 75, 76, 77
Communicates with a common suction hole 78 formed in the bottom portion, and the common suction hole 78 is provided at the bottom of the paper transport unit 1 via a flexible synthetic resin pipe 79 attached to the bottom surface side. It is connected to the waste liquid tank 62 provided in the. A second suction pump 80 is attached in the middle of the pipe 79.

Further, the through holes 74, 75, 76, 77 are provided at the lower portions thereof.
The valve bodies 81, 82, 83, 84 for opening and closing are elastic bodies 85, 86, 87, 8 each made of a spring or the like having a small elastic force.
It is attached while being biased by 8. In addition,
Print head 1 in each cap 70, 71, 72, 73
A rubber lining or the like for improving the airtightness is applied to the fitting portion with 3, 14, 15, 16 as required.

The caps 70, 7 constructed as described above
A timing belt 91 is attached to a pair of opposing pulleys 89, 90 attached to a support plate (not shown), and a drive motor 92 is attached to one pulley 89. Is installed,
The drive of the drive motor 92 causes the timing belt 91 to rotate, which causes the cap 70,
71, 72 and 73 are adapted to move to the printing unit 2 side.

The paper feed section 4 includes a paper feed cassette 93 for accommodating recording paper of a predetermined size arranged under the first and second ink cartridges 44 and 49, and a paper feed cassette 93.
Guide plate 94 for feeding the recording paper inside to the paper transport unit 1
And a pair of feed rollers 96 and 97 arranged on the upstream side and the downstream side of the guide plate 94, respectively.
The paper feed roller 95 is rotationally driven by a drive motor 98 fixed to a support plate (not shown), and the conveying roller pairs 96 and 97 are rotationally driven by a drive motor 99 fixed to a support plate (not shown). To be done. The paper feeding unit 4
Actually has a plurality of paper feed cassettes containing recording papers of different sizes.
A guide plate and a pair of transport rollers are provided,
Illustration is omitted here. The sheet feeding section 4 configured in this manner takes out the recording sheets one by one from the sheet feeding cassette 93 by the sheet feeding roller 95, guides the recording sheet to the guide plate 94 by the upstream side conveying roller pair 96, and the downstream side. The sheet is fed to the sheet conveying unit 1 by the side conveying roller pair 97.

The paper discharge unit 5 includes a guide plate 101 arranged on the downstream side of the paper conveyance unit 1, a conveyance roller pair 102 provided in the middle of the guide plate 101, and a guide plate 101.
Paper discharge roller pair 103 provided on the outlet side of the paper, and a paper discharge tray 104 provided on the downstream side of the paper discharge roller pair 103.
It is composed of In the paper discharge unit 5 configured as described above, the recording paper is fed from the paper conveyance unit 1 to the guide plate 101, the recording paper is fed to the downstream side by the conveyance roller pair 102, and the paper ejection roller pair 103 is used. Output tray 10
4. Discharge on top. The transport roller pair 102 and the paper discharge roller pair 103 are rotationally driven by a drive motor 105 fixed to a support plate (not shown).

FIG. 3 is a block diagram showing the main control arrangement of the ink jet recording apparatus constructed as described above. The inkjet recording device is designed to perform a printing operation based on an operation signal and an image signal input from an external device such as a personal computer.

The control unit 110 includes a CPU 111 and a storage unit 11.
2, an interface (I / F) unit 113, etc., and their operations are controlled in synchronization with the internal clock of the CPU 111.

The CPU 111 has control functions such as a recording control unit 114 and a mechanism control unit 115, and these recording control unit 114 and mechanism control unit 115 perform control operations in synchronization with each other. Further, the CPU 111 performs a control operation in the liquid replacement mode and the printing mode switched by the mode switching unit 116 including a mode switching button or the like provided in the operation unit not shown in FIG. The liquid replacement mode is a liquid replacement operation of ink or the like to the print head, and the print mode is a predetermined printing operation on a recording sheet or the like.

The storage unit 112 is composed of a ROM storing a program for controlling the operation of the ink jet recording apparatus, a RAM for temporarily storing data, and the like, and the CPU 111 is a control program stored in the ROM. Based on the above, the operation of the entire device is controlled.

The interface unit 113 receives data input from an external device such as a personal computer, and outputs an image signal to the recording control unit 114 and an operation signal such as a paper size to the mechanism control unit 115. Has become.

The recording control unit 114 controls the driving circuits 117, 118 of the print heads 13, 14, 15, 16 which constitute the printing unit 2 according to the respective color components of the input image signal.
Serial transmission to 119 and 120.

Each drive circuit 117, 118, 119, 12
Numeral 0 has a latch portion and is arranged at a proper position in each print head 13, 14, 15, 16 and temporarily latches the transmitted image signal for one line of recording paper, for example, and converts it into a parallel signal. .

Further, the recording control section 114 includes the drive circuit 11
The parallel signals converted by 7, 118, 119 and 120 are output to the corresponding piezoelectric elements 35, 36, 37 and 38 of the print heads 13, 14, 15 and 16 as pulse drive signals, and the nozzles 23, 24 and 25, The ejection of ink droplets from 26 is controlled. The image signal for one line is sequentially transmitted at a predetermined cycle, and thereby a two-dimensional image is printed.

The mechanism control section 115 is an operation signal input from a detection means 121 including various sensors such as a position detection sensor which are not shown in FIG. 1 and are provided at appropriate positions of predetermined components of the ink jet recording apparatus. Based on the above, via the drive circuit 122, the drive motor 11 of the paper transport unit 1, the drive motor 21 of the printing unit 2, the first flow path selection valve 54 of the printing unit 2, and the second flow path selection valve of the printing unit 2. 59, the first suction pump 60 of the printing unit 2, the second suction pump 80 of the capping unit 3, the drive motor 92 of the capping unit 3, the drive motor 98 of the paper feed roller 95, the drive motor of the pair of conveyance rollers 96 and 97. 99, conveyance roller pair 102 and paper discharge roller pair 1
No. 03 drive motor 105 is driven. The drive circuit 122 includes a power supply unit, electronic components such as transistors, and the like.

The ink jet recording apparatus constructed as described above operates as follows. First, the print head 13,
A liquid replacement operation when ink suitable for printing on a synthetic resin sheet for OHP, for example, which is filled in 14, 15, 16 is replaced with ink suitable for printing on recording paper will be described. Now, when the liquid change mode is set by the mode switching means 116, the ink jet recording apparatus in the state shown in FIG. 1 causes the print heads 13, 14, 15, 16 of the printing unit 2 to print on the paper as shown in FIG. The cap 70, 71, 72 of the capping unit 3 moves while moving away from the transport belt 10 of the transport unit 1 to the upper side.
73 moves to the lower position of the print heads 13, 14, 15, 16 and then the print heads 13, 14, 15, 16 move to the lower side and engage with the caps 70, 71, 72, 73. At this time, the caps 70, 71, 72, 73 cover the nozzles 23, 2 of the print heads 13, 14, 15, 16.
The surfaces 4, 25, and 26 are airtightly covered.

Next, the print heads 13, 14, 15, 1
The first flow path selection valve 54 of 6 is the liquid tank 45, 4 respectively.
Liquid tanks 40, 41, 42, 43 from the 6, 47, 48 side
The liquid tanks 40, 41, 42 and 43 are connected to the first external flow path 53, and the second flow path selection valve 59 is connected to the liquid tanks 45, 46, 47 and 48 from the liquid tanks 45, 46, 47 and 48 side respectively. The waste liquid tank 62 is switched to the tank 62 side.
Are connected to the second external flow path 57. In this state, the first suction pump 60 rotates to rotate the print heads 13, 14, 1
The ink filled in the nozzles 5 and 16 is the first suction pump 6
The ink contained in the liquid tanks 40, 41, 42, 43 is discharged from the second liquid communication section 52 side to the outside by the suction force of 0, and the print head 13 is discharged from the first liquid communication section 51 side. , 14, 15, 16 are drawn into the common liquid chamber 3
1, 32, 33, 34 are filled. The ink discharged to the outside is stored in the waste liquid tank 62 via the third connection flow path 61.

As described above, the first suction pump 60
When the nozzles 23, 24, 25, 26 are not hermetically sealed when the nozzles 23, 24, 25, 26 are rotated,
Although air is sucked from the nozzles and the ink is not drawn in from the first liquid communication portion 51 side, in this embodiment, the nozzle 2 is used.
Caps 70, 71, 72, 3, 24, 25, 26 faces
Nozzles 23, 24, 2 since 73 is airtightly covered.
The surfaces 5 and 26 are in an airtight state, and ink is reliably drawn in.

Ink drawn into the print heads 13, 14, 15, 16 by continuing the rotation of the first suction pump 60 passes through the second flow path selection valve 59 to the third connection flow path 6
When it reaches the inside of 1, the second flow path selection valve 59 is switched by the output from the detection device configured to include the sensor installed in the third connection flow path 61, and the second external flow path. 57 to the liquid tanks 40, 4 via the fourth connection flow path 63.
1, 42, 43 are connected. As a result, the print head 1
3, 14, 15, 16 and liquid tanks 40, 41, 42, 4
A closed circuit is formed between the two. This makes the second
Overflows the external flow path 57 of the fifth connection flow path 6
Ink that reaches 3 is stored in the liquid tank 4 without leaking outside.
It will be returned to 0, 41, 42, 43.

In the detection device constituted by including the sensor installed in the third connection flow path 61, for example, the ink filled in the print heads 13, 14, 15, 16 is supplied to the third connection flow path. The sensor detects this when it reaches the inside of the path 61, and when the time required for all the ink filled in the print heads 13, 14, 15, 16 to be discharged to the waste liquid tank 62 has elapsed, the second A switching signal of the flow path selection valve 59 is output. By this switching signal, the second flow path selection valve 59 is connected to the same liquid tank 40, 41, 42, 43 as the first flow path selection valve 54.

At the same time when the second flow path selection valve 59 is switched, the first suction pump 60 stops rotating and the second suction pump 80 connected to the caps 70, 71, 72, 73 rotates. . When the second suction pump 80 rotates, the suction force of the second suction pump 80 causes the valve elements 81, 82, 83, 84 of the caps 70, 71, 72, 73 to move to the elastic bodies 85, 86, 87.
It moves downward against the elastic force of 88, and the nozzles 23, 2
The surfaces 4, 5, and 26 are in a negative pressure state as compared with the first and second liquid communication portions. As a result, the common liquid chamber 3
The ink filled in 1, 32, 33, 34 is stored in the common liquid chamber 3
Nozzles 23, 24, 25, 2 from 1, 32, 33, 34
6 side, the nozzles 23, 24, 25, 26
To be filled. The ink remaining in the nozzles 23, 24, 25, 26 without being discharged from the second liquid communication portion side is discharged to the outside from the nozzle 23, 24, 25, 26 surface side. As a result, the print heads 13, 14, 15, 16 are filled with new ink, and the replacement of ink is completed.

When the replacement of the ink in the print head is completed as described above, the ink jet recording apparatus can print on the recording paper. Here, when the print mode is set by the mode switching unit 116, the inkjet recording apparatus is set to the initial state shown in FIG. In this state, the conveyance roller pairs 96, 97, 102 and the paper discharge rotor pair 103 rotate based on an operation signal from an external device such as a personal computer, and the conveyance belt 10 of the paper conveyance unit 1 also rotates. At the same time, the paper feed roller 95 of the paper feed unit 4 rotates to feed the recording paper from the paper feed cassette 93, and the recording paper is fed to the paper feed unit 1 via the guide 94 by the feed roller pair 96 and 97. To be done.
The conveyance roller pair 97 is controlled in drive via a clutch or the like, and feeds the recording paper to the paper conveyance unit 1 in synchronization with the printing operation of the print heads 13, 14, 15, and 16.

The recording sheet fed to the sheet conveying section 1 is conveyed to the downstream side by the conveying belt 10, and the print heads 13, 14, 15, 16 of the printing section 2 move the sheets in the middle of the transfer. Color printing is performed based on the image signal transmitted from the external device. If the image is monochrome,
For example, the black print head 13 performs monochrome printing. The recording paper for which printing has been completed is conveyed by the conveyor belt 1.
The sheet is fed to the guide 101 of the sheet discharge unit 5 by 0, and is discharged to the sheet discharge tray 104 by the pair of transport rollers 102 and the pair of sheet discharge rollers 103.

When the transmission of the image signal from the external device is completed and the printing on the recording paper is completed, the ink jet recording device is in the same state as in the liquid replacement mode shown in FIG. That is, the print heads 13, 14, 15, 16
Moves away from the paper transport unit 1 and moves to the upper side,
The caps 70, 71, 72, 73 are the print heads 13, 1
The print heads 13, 14, 15 and 16 are moved to the lower side and are fitted to the caps 70, 71, 72 and 73. Then, in this state, the second suction pump 80 of the capping unit 3 operates,
Ink is forcibly sucked from the nozzles 23, 24, 25 and 26, and an ink discharge recovery operation is performed. This ink ejection recovery operation is performed regardless of whether or not the nozzle is clogged, and is appropriately performed by the same operation as above even during the printing operation.

Although the ink jet recording apparatus according to the present invention is constructed and operates as described above, various modifications as described below are possible. For example, in the above embodiment, the discharging means for discharging the liquid material filled in the print head and the first filling means for drawing the liquid material in the liquid tank from the first liquid communicating portion side to fill the common liquid chamber. As the first suction pump 6
0, the liquid in the common liquid chambers 31, 32, 33, 34 is transferred from the common liquid chambers 31, 32, 33, 34 to the nozzle 23,
Nozzles 23, 2 by pouring on the surface side of 24, 25, 26
Although the second suction pump 80 is used as the second filling means for filling 4, 25, and 26, as shown in FIG. 5, instead of the first suction pump 60, the second external flow path 57 is used. By connecting the pump 125 that can be driven in the normal and reverse directions to this, the pump 125 can function as both the first suction pump 60 and the second suction pump 80.

Although FIG. 5 corresponds to FIG. 2 and relates to the print head 13, the other print heads 14, 15 and 16 have the same structure. Therefore, as in the case of FIG. 2 described above, in the following description, the same reference numerals are given to the print heads other than the print head 13 for the constituent parts shown only in FIG. To do.

That is, the pump 125 discharges the ink filled in the print heads 13, 14, 15, 16 to the outside, and the liquid tanks 40, 41, 42, 43 (or,
By driving the ink in the liquid tanks 45, 46, 47, 48) into the print heads 13, 14, 15, 16 (this direction is referred to as positive drive), the same function as that of the first suction pump 60 is achieved. To have. Further, the same function as the second suction pump 80 is provided by driving in the opposite direction (this direction is called reverse driving). Switching between the normal drive and the reverse drive of the pump 125 is performed by an output signal from a detection device including a sensor provided in the third connection flow path 61 as in the case shown in FIG.

When the pump 125 is driven in the reverse direction, at the same time, the flow path selection valve 54 connected to the first external flow path 53 is switched so that the first external flow path 53 is closed. When the first flow path selection valve 54 does not have a function of closing the first external flow path 53, the first flow path selection valve 5
Another switching valve may be provided closer to the first liquid communication portion 51 side than 4 and the first external flow path 53 may be closed by this switching valve. In this case, this switching valve is included in the first flow path selection valve 54.

When the pump 125 is reversely driven in this state, the print heads 13 and 14, on the side of the second liquid communicating portion 52,
A pressure is applied in a direction to push back the ink drawn into 15 and 16 to the first liquid communication portion side. However, since the first external flow path 53 is closed as described above, the print head 1
The ink drawn into 3, 14, 15, 16 and filled in the common liquid chamber flows into the nozzles 23, 24, 25, 26 and is filled in the nozzles. The pump 125 is the first
It is controlled by the CPU 111 and the like like the suction pump 60 and the like, and is driven by the drive circuit 122 shown in FIG.

The pump 125 has the first and second pumps.
4, the nozzles 23, 24 of the print heads 13, 14, 15, 16 are, like the suction pumps 60, 80 of FIG.
It operates with the surfaces 25 and 26 covered with the caps 70, 71, 72 and 73. In this case, when the pump 125 is driven in the reverse direction, the pressure inside the caps 70, 71, 72, 73 becomes higher than that at the outside, so that the valve bodies 81, 82, 83, 84 of the elastic bodies 85, 86, 87, 88 are arranged. It moves to the lower part against the elastic force. As a result, the surfaces of the nozzles 23, 24, 25, 26 become non-airtight, and the common liquid chambers 31, 32, 33, 34 are formed.
The ink filled in the nozzles will surely flow into the surfaces of the nozzles 23, 24, 25 and 26.

The valve elements 81, 82, 83, 84 of the caps 70, 71, 72, 73 are made of the elastic material 8 as described above.
Instead of controlling by the elastic force of 5, 86, 87, 88,
It may be electromagnetically operated in synchronization with the operation of the second suction pump 80 or the reverse drive operation of the pump 125.
Further, the valve bodies 81, 82, 83, 84 can be eliminated, and in this case, the caps 70, 71, 72, 73 are moved relative to the print heads 13, 14, 15, 16 so that the print heads 13 can be moved. , 14, 15, 16 and a gap is formed between the nozzles 23, 24, 25, and 26 so that the surfaces thereof are not hermetically sealed.

In the structure shown in FIG. 5, the print heads 13, 14, 15, 16 and the liquid tanks 40, 4 are used.
1, 42, 43 (or liquid tanks 45, 46, 47, 4
8), no circulation path is formed between them, and in this case, the second flow path selection valve 59 having the configuration shown in FIG. 2 becomes unnecessary. Such a structure in which the circulation path is not formed can be adopted also in the case of the structure shown in FIG. 2, and conversely, the structure in which the circulation path is formed shown in FIG. 2 can be adopted in the structure shown in FIG. .

Further, in the above-described embodiment, the ink filled in the print heads 13, 14, 15, 16 by the first suction pump 60 or the forward / reverse drivable pump 125 is applied to the second liquid communicating portion 52 side. When discharged from the first flow path selection valve 54, the liquid tanks 40, 41, 42, 43 (or the liquid tanks 45, 46, 47, 48) are connected to the first external flow path 53. Print heads 13, 1
The discharge of the ink filled in the ink tanks 4, 15, 16 and the liquid tanks 40, 41, 42, 43 (or the liquid tanks 45, 4)
6, 47, 48) and the drawing of the ink from the first liquid communication portion 51 side are performed at the same time. However, the liquid tanks 40, 41, 42, 43 (or the liquid tanks 45, 4
The inks (6, 47, 48) may be drawn in from the first liquid communicating portion 51 side after the inks filled in the print heads 13, 14, 15, 16 have been discharged. In this case, for example, the first flow path selection valve 54 having a structure capable of opening the first external flow path 53 to the atmosphere is used, and the print heads 13, 14, 15, 16 are filled. When discharging the ink, the first external flow path 53 may be left open to the atmosphere.

Further, in the above-described embodiment, the replacement of the liquid material when the ink and the ink are of the same kind has been described, but the different liquid materials such as the ink and the solvent may be replaced. That is, in FIG. 6, the liquid tank 40 contains ink, and the liquid tank 127
Is the one containing the solvent. The solvent here means
Water, alcohol, a mixture of water and alcohol, a mixture of water, alcohol and glycol, and the like. Although FIG. 6 shows the print head 13, another print head 1
The same configuration is applied to 4, 15, and 16. Therefore, as in the case of FIG. 2 and FIG. 5 described above, in the following description, the constituent parts shown only in FIG.
For convenience, it is assumed that the same reference numerals are given to the print heads other than the print head 13. For the liquid tank 127 containing the solvent, the print heads 13 and 1 are used.
4, 15, 16 can be shared.

In the configuration shown in FIG. 6, each print head 1
The liquid tanks 40, 41, 42, 43 or the liquid tank 127 are selectively connected to the first external flow path 53 by switching the first flow path selection valves 54 of 3, 14, 15, and 16. Has become. The liquid tanks 40, 41, 42, 43 or the waste liquid tank 62 can be selectively connected to the second external flow path 57 by switching the second flow path selection valve 59. 13, 14, 15, 16 and the liquid tanks 40, 41, 42, 43 form a circulation path.

However, it is also possible not to form the circulation path as shown in FIG. 5, and in such a case, the second flow path selection valve 59 becomes unnecessary. Also in the case of the configuration shown in FIG. 6, the exchange of the ink and the solvent is performed by the operation of the first and second flow path selection valves 54 and 59, the first suction pump 60 and the like similar to the above. Such exchange of ink and solvent can also be performed by the configuration using the pump 125 that can be driven in the forward and reverse directions shown in FIG.

With the above structure, the print heads 13, 14,
By replacing the ink filling the inks 15 and 16 with a solvent, it is possible to prevent the nozzles 23, 24, 25 and 26 from being clogged when the ink jet recording apparatus is not used. That is, when the ink jet recording apparatus is not used, conventionally, the surfaces of the nozzles 23, 24, 25, and 26 are capped with the caps 70 and 7 in the state shown in FIG.
By covering with 1, 72, 73, the nozzles 23, 24,
Although the evaporation of water in the ink in 25 and 26 is suppressed to delay the coagulation of the ink, it is not possible to completely prevent the coagulation of the ink by merely covering with the caps 70, 71, 72 and 73. It was possible.

However, if the ink is replaced with a solvent,
Since there is no ink in the nozzles 23, 24, 25, 26, even if the solvent evaporates, the nozzles 23, 24, 2
No clogging occurs in Nos. 5 and 26. When using the ink jet recording apparatus, it is only necessary to replace the solvent with which the print head is filled with the ink. Such replacement of the ink and the solvent is performed by automatically replacing the ink with the solvent when the main power of the inkjet recording apparatus is turned off.
It is also possible to automatically replace the solvent with the ink when set to N.

Further, in the above embodiment, the sheet conveying section 1
Conveying belt 10, sheet feeding roller 95 of sheet feeding section 4 and conveying roller pairs 96 and 97, and conveying roller pair 102 of sheet discharging section 5.
And the discharge roller pair 103 are different drive motors 1
Although rotating at 1, 98, 99, 105, for example, it is possible to rotate with the same drive motor except for the paper feed roller 95, or to rotate all with one drive motor,
It is also possible to appropriately switch the drive with a clutch.

Further, in the above embodiment, the print head 1
The caps 7, 71, 72 and 73 are moved to the printing unit 2 side only by moving the caps 7, 14, 15 and 16 only up and down on the sheet conveying unit 1.
0, 71, 72, 73 are only the raising / lowering operation at the home position, and the print head 13,
The configuration may be such that 14, 15, 16 are moved to the caps 70, 71, 72, 73 side.

Furthermore, the printing unit 2 can be constituted by only one print head when only monochrome printing is required. Further, the ink discharge recovery operation of the print heads 13, 14, 15, 16 is performed by the second suction pump 8 in the above embodiment.
However, it is also possible to reversely drive the pump 125 provided in the second external flow path 52 with the first external flow path 53 closed. Further, the inkjet recording device may have a function as a facsimile or a function as a copying machine.

[0068]

As described above, according to the first to fifth aspects of the invention, a plurality of liquid tanks containing the liquid material and a plurality of liquid tanks are selected on the first liquid communicating portion side of the print head. Switching means for one-time connection, means for discharging the liquid material filled in the print head from the second liquid communication portion side to the outside, and drawing the liquid material in the liquid tank from the first liquid communication portion side It is composed of first filling means for filling the common liquid chamber and second filling means for pouring the liquid material of the common liquid chamber filled by the first filling means from the common liquid chamber side to fill the nozzle. Therefore, the liquid material filled in the print head can be replaced with another liquid material.

Further, according to the invention of claim 2, the switching means is constituted by the flow path selection valve provided in the flow path on the side of the first liquid communicating portion, and the discharging means and the first filling means are the first. The first suction pump provided in the flow path of the second liquid communication portion side,
Since the filling means of (1) is composed of a cap that covers the nozzle surface in an airtight manner and a second suction pump provided in this cap,
It becomes possible to reliably replace the liquid material filled in the print head with another liquid material.

According to the third aspect of the invention, since the first suction pump is operated while the nozzle surface of the print head is airtightly covered with the cap, excess air is not sucked from the nozzle surface side. It is possible to reliably discharge the liquid material filled in the print head from the second liquid communication portion side to the outside, and to reliably draw the liquid material in the liquid tank into the print head from the first liquid communication portion side. become.

Further, according to the invention of claim 4, the switching means is provided in the flow passage on the side of the first liquid communicating portion, and the flow passage can be closed. A second valve is composed of a selection valve, a pump capable of forward and reverse driving is connected to the flow path on the second liquid communication portion side, and a pump which normally drives the discharging means and the first filling means. Since the means is constituted by a pump that drives in the reverse direction, the liquid material filled in the print head can be reliably replaced with another liquid material.

According to the fifth aspect of the invention, since the pump capable of forward and reverse driving is driven in the forward direction with the nozzle surface of the print head covered with the cap in an airtight manner, excess air is sucked from the nozzle surface side. Therefore, the liquid material filled in the print head can be reliably discharged to the outside from the second liquid communication portion side, and the liquid material in the liquid tank can be reliably drawn into the print head from the first liquid communication portion side. become able to.

[Brief description of drawings]

FIG. 1 is a front view of an inkjet recording apparatus according to the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of the inkjet recording device shown in FIG.

3 is a block diagram illustrating a control configuration of the inkjet recording apparatus shown in FIG.

FIG. 4 is a front view of the inkjet recording apparatus for explaining the operation of the inkjet recording apparatus shown in FIG.

FIG. 5 is a sectional view corresponding to FIG. 2 in another embodiment of the inkjet recording apparatus of the present invention.

FIG. 6 is a sectional view corresponding to FIGS. 2 and 5 in another embodiment of the inkjet recording apparatus of the present invention.

FIG. 7 is a cross-sectional view of a main part of a print head of a conventional inkjet recording device.

[Explanation of symbols]

 1 Paper Conveying Section 2 Printing Section 3 Capping Section 4 Paper Feeding Section 5 Paper Discharging Section 13, 14, 15, 16 Print Heads 23, 24, 25, 26 Nozzles 40, 41, 42, 43 Liquid Tanks 45, 46, 47, 48 Liquid Tank 51 First Liquid Communication Portion 52 Second Liquid Communication Portion 53 First External Flow Path 54 Switching Means (First Flow Path Selection Valve) 57 Second External Flow Path 59 Switching Means (Second Flow path selection valve) 60 first suction pump 62 waste liquid tank 70, 71, 72, 73 cap 80 second suction pump 125 pump capable of forward and reverse driving

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kikunosuke Tsuji 1-228 Tamatsukuri, Chuo-ku, Osaka Mita Engineering Co., Ltd. (72) Takeshi Watanabe 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Within Kogyo Co., Ltd.

Claims (5)

[Claims] 1. A plurality of nozzles are formed in an array on one surface, and each nozzle is connected to a common liquid chamber via a pressure chamber, and both ends of the common liquid chamber are communicated to the outside with first and second nozzles.
An ink jet recording apparatus having a print head having a liquid communication part formed therein, capable of replacing a liquid material filled in the print head with another liquid material, wherein the liquid material is stored. A plurality of liquid tanks, a switching means for selectively connecting the plurality of liquid tanks to the first liquid communication portion side, and a liquid material filled in the print head from the second liquid communication portion side. The discharging means for discharging the liquid to the outside, the first filling means for filling the common liquid chamber with the liquid material of the liquid tank from the first liquid communicating portion side, and the common liquid chamber filled by the first filling means. An ink jet recording apparatus, comprising: a second filling unit that fills the nozzle with the liquid material from the common liquid chamber side. 2. The ink jet recording apparatus according to claim 1, further comprising: a control unit that controls the operation of each unit, and a cap that relatively moves between the print head and covers the nozzle surface in an airtight manner. The switching means is composed of a flow path selection valve connected to the flow path on the side of the first liquid communication portion, and the discharging means and the first filling means are the second flow path.
The first suction pump connected to the flow path on the liquid communication part side of the second filling means, the second filling means is composed of the cap and the second suction pump connected to the cap, and the control means is The liquid material filled in the print head by operating the flow path selection valve to connect a predetermined liquid tank to the flow path on the side of the first liquid communication unit and operating the first suction pump. Is discharged to the outside from the second liquid communication portion side,
In addition, the liquid material in the liquid tank is drawn into the print head from the first liquid communication portion side to fill the common liquid chamber, after which the operation of the first suction pump is stopped, and the nozzle surface is capped. An ink jet recording apparatus, characterized in that the second suction pump is operated in a state where it is covered in an airtight manner, whereby the liquid material filled in the common liquid chamber is poured from the common liquid chamber to fill the nozzle. 3. The ink jet recording apparatus according to claim 2, wherein the control means operates the first suction pump in a state where the nozzle surface is covered with the cap in an airtight manner, thereby filling the print head. The discharged liquid material is discharged to the outside from the second liquid communication portion side, and the liquid material in the liquid tank is drawn into the print head from the first liquid communication portion side to fill the common liquid chamber. Inkjet recording device. 4. The ink jet recording apparatus according to claim 1, further comprising a control means for controlling the operation of each of the means, the switching means being connected to the flow path on the side of the first liquid communicating portion, and The flow path is composed of a flow path selection valve that can be closed without being connected to any of the liquid tanks, and can be driven forward and backward to the flow path on the side of the second liquid communication unit. A pump is connected, the discharge means and the first filling means are the positively driving pumps, the second filling means are the reversely driving pumps, and the control means is the flow path selection valve. It is operated to connect a predetermined liquid tank to the flow path on the side of the first liquid communication portion, and positively drive the pump so that the liquid material filled in the print head is discharged from the second liquid communication portion side. Liquid to be discharged to the outside and a prescribed liquid tank The liquid material is drawn into the print head from the first liquid communication portion side to fill the common liquid chamber, and then the flow path selection valve is operated to close the flow path on the first liquid communication portion side, and An ink jet recording apparatus, characterized in that a pump is driven in reverse so that a liquid material filled in a common liquid chamber is poured into the common liquid chamber to fill a nozzle. 5. The ink jet recording apparatus according to claim 4, further comprising a cap that moves relative to the print head to cover the nozzle surface in an airtight manner, and the control means uses the cap to cover the nozzle surface. The pump is normally driven in a state where it is covered in an airtight manner, whereby the liquid material filled in the print head is discharged to the outside from the second liquid communication portion side, and the liquid material in the liquid tank is first discharged. The ink jet recording apparatus is characterized in that the common liquid chamber is filled by being drawn into the print head from the liquid communication part side of the above.