JPH09277636A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent contamination of the rearmost part in the feed direction of a recording medium having definite length or a part of a long recording medium by a recording means in an ink jet recording apparatus. SOLUTION: In an ink jet recording apparatus constituted so as to feed a recording medium toward a recording means for emitting ink to the recording medium corresponding to an image signal to perform recording by a feed means, first discharge means 13, 13a are arranged on the downstream side in the recording medium feed direction of the recording means 20 and a second discharge means 14 is arranged on the downstream side in the recording medium feed direction of the first discharge means 13, 13a and the first discharge means 13, 13a energize the rearmost part of the recording medium in the direction separated from the recording means to discharge paper to prevent the contamination of the recording medium by the recording means.

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 for recording an image or the like by ejecting ink from a recording means to a recording medium, and particularly, it preferably conveys a recording medium such as cut paper or continuous paper. The present invention relates to an inkjet recording apparatus having an inkjet recording unit that records on a recording medium that is conveyed.

[0002]

2. Description of the Related Art Conventionally, recording devices having a pin feed tractor have been used as output devices for personal computers, word processors, facsimiles and the like. FIG. 5 shows the configuration of the conventional example
This will be described with reference to FIG.

FIG. 5 is a schematic sectional view showing a structure of a conventional ink jet recording apparatus. As a recording medium conveying means, a conveying roller 450 and pinch rollers 451a and 451b which are pressed by the conveying roller 450 and are driven to rotate are provided. A so-called U-turn path A is provided so as to wind and convey the recording medium around 450.

For example, when cut paper is used as the recording medium, the conveying roller 450 and the pinch roller 45 are used.
The cut sheet is sandwiched between the la and 451b and is conveyed by the frictional force generated between them.

On the other hand, when continuous paper (hereinafter referred to as fanfold paper) is used as a recording medium, a pin hole of fanfold paper is engaged with a pin 452a provided on a pin feed tractor (hereinafter referred to as tractor) 452. The transport roller 450 and the pinch roller 4
The pressure is applied between 51a and 451b, and the frictional force generated between them is conveyed to the recording unit.

At this time, there is no problem if the transport amounts of the tractor 452 and the transport roller 450 can always be set to be the same, but in reality, a transport speed difference occurs due to the dimensional accuracy of the two or the dimensional change due to the environment. Therefore, the pressed state of the pinch rollers 451a and 451b that press the conveying roller is released so that the conveying force of the conveying roller 450 is not applied to the fanfold paper.

Then, the conveyed recording medium is recorded by the ink jet head 453 according to the image information and then pulled up and discharged by the sheet discharge roller 454 and the pinch roller 455 which presses the sheet.

Unlike cut paper, continuous paper is rarely lifted from the platen at the lower end, but perforation may be lifted. However, the pressing force of the spur 455 against the paper discharge roller 454 is not released even when the continuous paper is piled up, and thus the perforation can be prevented from floating.

[0009]

However, in the case of recording on a cut sheet, when the lower end of the cut sheet comes off the pinch roller 451a as shown in FIG. 6, the cut sheet is discharged by the discharge rollers 454 and 454. Spur 45 being urged by
It will be pinched only at 5. As a result, the lower end of the cut sheet floats above the platen 456 due to the moment due to the weight of the cut sheet, and the inkjet head 45
I will touch 3. If printing is continued in this state, the printing surface will become dirty, or the inkjet head 453 will
There was a risk that the left and right edges of the cut paper would be caught, causing a jam.

In the case of recording continuous paper, the continuous paper is wound around the paper discharge roller 454. Due to the influence of this winding, the paper discharge roller 454 is worn and deteriorated,
There was a risk of paper jams.

The present invention solves the above problems, and a first object of the present invention is to prevent stains on the recording surface after printing due to paper floating that occurs at the bottom edge printing of cut sheets. An object of the present invention is to provide an ink jet recording apparatus provided with a preventing means.

A second object of the present invention is to provide an ink jet recording having means for preventing the paper discharge roller from being worn due to the winding of the continuous paper and the occurrence of a paper jam in the structure which achieves the above first object. To provide a device.

[0013]

In order to achieve the above object, the invention of an ink jet recording apparatus according to claim 1 is a recording means for ejecting ink to a recording medium according to an image signal to perform recording. And a first transporting unit for transporting a recording medium of a fixed length toward the recording unit, the first discharging unit being located downstream of the recording unit in the recording medium transporting direction. When,
A second ejecting unit located downstream of the first ejecting unit in the recording medium conveyance direction is provided, and the first ejecting unit comprises:
It is characterized in that the rearmost portion of the recording medium is urged in a direction of separating it from the recording means and the sheet is discharged.

According to another aspect of the present invention, there is provided an ink jet recording apparatus, wherein recording means for ejecting ink to a recording medium according to an image signal to perform recording, and conveying the recording medium toward the recording means. An ink jet recording apparatus comprising: a first transporting means for transporting a long recording medium to the first transporting means;
A first ejecting unit located downstream of the recording unit in the recording medium conveying direction and a second ejecting unit located downstream of the first ejecting unit in the recording medium conveying direction are provided. Is characterized in that a part of the recording medium is urged in a direction to be separated from the recording means and the sheet is discharged.

The invention of an ink jet recording apparatus according to a third aspect is the ink jet recording apparatus according to the first or second aspect, wherein the second ejecting means has a structure which is more excellent in abrasion resistance than the first ejecting means. It is characterized by being

The invention of an ink jet recording apparatus according to a fourth aspect is the ink jet recording apparatus according to any one of the first to third aspects, wherein the first discharging means and the conveying speed of the first conveying means are different. The second discharging means is accelerating, and the speed ratio of the second discharging means to the conveying speed of the first conveying means is higher than the speed ratio of the first discharging means to the conveying speed of the first conveying means. It is characterized by a large setting.

The invention of an ink jet recording apparatus according to a fifth aspect is the ink jet recording apparatus according to any one of the first to fourth aspects, wherein the first ejecting means and the second ejecting means are provided.
The discharging means has a roller, and the material of the roller is different.

The invention of an ink jet recording apparatus according to a sixth aspect is the ink jet recording apparatus according to any one of the first to fourth aspects, wherein the second discharging means has a roller, and the roller is one of the recording medium. It is characterized in that the groove is formed parallel to the direction orthogonal to the rotation direction for discharging.

The invention of an ink jet recording apparatus according to a seventh aspect is the ink jet recording apparatus according to the fifth or sixth aspect, wherein the first discharging means has a spur facing the roller on the upstream side in the recording medium conveying direction. The second ejecting means has a pair of spurs facing the roller on the upstream side and the downstream side in the recording medium conveyance direction.

The invention of an ink jet recording apparatus according to an eighth aspect is the ink jet recording apparatus according to the second aspect, wherein the second conveying means is a pin feed tractor for conveying continuous paper.

According to a ninth aspect of the invention of an ink jet recording apparatus, in the ink jet recording apparatus according to the second aspect, the elongated recording medium is conveyed while being in contact with the outer peripheral surface of the second discharging means. Is characterized by.

The invention of an ink jet recording apparatus according to a tenth aspect is the ink jet recording apparatus according to any one of the first to ninth aspects, wherein the recording means produces electrothermal conversion for generating thermal energy for ink ejection. It is characterized by having a body.

The invention of an ink jet recording apparatus according to an eleventh aspect is the ink jet recording apparatus according to the tenth aspect, wherein the recording means utilizes the film boiling generated in the ink by the thermal energy applied by the electrothermal converter. Ink is ejected from the ejection port.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. 1 and 2 show an inkjet recording apparatus according to an embodiment of the present invention. FIG. 1 shows an automatic paper feeding unit (hereinafter referred to as ASF (Auto
(Also referred to as a Sheet Feeder), and FIG. 2 is a cross-sectional view showing a main configuration of the ASF shown in FIG. 1 in a 2-bin configuration. Further, FIG. 3 is a sectional view of an essential part showing a state in which a cut sheet is selected.
FIG. 4 is a cross-sectional view of a main part showing a state in which continuous paper is selected.

The ink jet recording apparatus of this embodiment can use, as the recording medium, ordinary recording paper, single-cut paper such as postcard (hereinafter also referred to as cut paper), and continuous paper such as fanfold paper. is there.

That is, when cut sheets are used, usually ASF is used for feeding or so-called manual feeding.

The ink jet recording apparatus is provided with an electrothermal converter for generating thermal energy for ejecting ink, and utilizes film boiling generated in ink by the thermal energy applied by the electrothermal converter. The ink is ejected from the ejection port to record on the recording medium.

As is apparent from FIG. 2, the ASF has two bins 30a and 30b, so that, for example, cut sheets of different sizes can be set at the same time, and two kinds of sizes can be selected according to the user's selection operation. The cut paper of can be used. The paper feed mechanism of each bin 30a, 30b is composed of the same mechanism. That is, the plurality of cut sheets (the cut sheets are not shown in FIG. 2) stacked on the pressing plates 31a and 31b are pressed against the pickup rollers 33a and 33b by the pressing force of the springs 32a and 32b. The pickup roller 33a or 33b, which is biased and rotates in response to a paper feed start command, feeds the paper while separating the sheets one by one.

In FIG. 3, when a cut sheet is used, when the release lever 251 (FIG. 1) is set to the cut sheet selection state, the pinch roller 11 held by the pinch roller holder 5 causes the pinch roller spring 245 to move the conveyance roller. Energized to 10. Similarly, the auxiliary roller 16 held by the pinch roller holder 5 so as to be vertically movable is urged by the auxiliary roller spring 248 also provided on the pinch roller holder 5 toward the transport roller 10. As a result, the cut sheet fed from the ASF is conveyed to the recording area side along the conveying path formed around the cut sheet by the rotation of the conveying roller 10.

On the side of the recording area, the needle roller 12 is held by the needle roller holder 223 and is urged by the needle roller spring 246 toward the conveying roller 10.
At this time, the needle roller spring 246 is deflected by the projection 241c of the release shaft 241, and a pressure contact force is generated by a spring elastic force centered on the intersection 246a. A transport force is further applied to the cut paper here, and the cut paper is transported between the inkjet head 20 and the platen 24.

The conveyance here is carried out intermittently for each scanning of the ink jet head 20, and the amount of the conveyance is a plurality of ink ejection ports provided in the ink jet head 20 in the conveyance direction of the cut paper. It is performed according to the array length. The cut sheet on which the recording is performed by the conveyance for each scan and the ink ejection from the inkjet head 20 in the meantime is the gap roller 1 provided near the downstream of the head 20 in the conveyance direction of the cut sheet.
3 and the rotation of the paper discharge roller 14 downstream of the roller 13 (and the spurs 13a and 14 pressed against them).
According to a), the sheets are sequentially conveyed above the apparatus. The gap roller 13 is divided into a plurality of parts on the same rotating shaft and arranged at intervals in the axial direction (so-called segment type), or is arranged as an integral type without being separated in the axial direction. The roller 14 is similarly arranged on the rotating shaft.

When the lower end of the cut sheet comes off the needle roller 12, the lower end of the cut sheet is attached to the platen 24 by the nip pressure between the gap roller 13, the sheet discharge roller 14 and the spurs 13a and 14a pressed by these rollers. Power acts. This is because the centers of the spurs 13a and 14a are displaced to the upstream side in the transport direction with respect to the centers of the gap roller 13 and the paper discharge roller 14 so that the cut paper is so-called reverse warped. As a result, the lower end of the cut sheet is prevented from floating on the inkjet head side and is contaminated during scanning of the carriage.

When the lower end of the ejected paper hits the ejecting roller, the groove is formed in the ejecting roller 14 and the pressure contact force of the spur 14b is stacked on the stacker portion 24a integrally formed with the platen, so that the ejecting is performed well. Done. If there is no groove, the lower edge of the paper discharge may collect between the paper discharge roller and the spur, and the stack may not be completed.If the next page is discharged in this state, the next page will come in front of the previous page and will be discharged. The paper becomes defective.

When continuous paper (fanfold paper) is used, ASF is not used, and continuous paper fed from the paper feed port 35 shown in FIG. 2 is driven by a pin feed tractor (hereinafter also referred to as tractor) 3. Be transported.

When the release lever 251 (see FIG. 1) is set to the continuous paper selection state, the release shaft 241 rotates, and the projection 241b presses the pinch roller holder 5 as shown in FIG. 11 is a conveyance roller 10
And is retracted from the transport path. The pinch roller holder 5 has the rotation fulcrum 5a at the needle roller holder 2
The auxiliary roller 16 provided on the 23 side and held by the pinch roller holder 5 so as to be movable up and down similarly tries to move in the direction away from the conveying roller 10, but is moved to the conveying roller 10 by the auxiliary roller spring 248. It can be kept to weaken the carrying power of.

Further, the pressing of the needle roller spring 246 by the protrusion 241c is released, and the pressure contact force of the needle roller 12 to the conveying roller 10 is relieved.

The continuous paper conveyed to the recording area side is successively conveyed to the upper side of the apparatus by the intermittent conveyance of each scanning of the ink jet head 20, as in the case of the above-mentioned cut paper, and recording is performed during this. .

Unlike cut sheets, continuous paper is rarely lifted from the platen at the lower end, but perforations may be lifted. However, even in the case of continuous paper, the pressing force of the spurs 13a and 14a on the gap roller 13 and the paper discharge roller 14 is not released, and thus the perforation can be prevented from floating.

Further, since the gap roller 13 and the paper discharge roller 14 are accelerated with respect to the conveying speed of the conveying roller 10, it is possible to further suppress the floating of perforations. In this embodiment, the transport roller 10 (φ38.808 m
Gap roller 13 (φ14.844m)
m) has a speed increasing ratio of + 2%, and the discharge roller 14 (φ14.901 mm) has a speed increasing ratio of + 2.4% with respect to the conveying roller 10.
And

The continuous paper is in almost line contact with the gap roller 13 (carriage scanning direction), but is wound about the paper discharge roller 14 at an angle of about 55 °.
In order to reduce wear deterioration due to the influence of this winding,
In this embodiment, the material of the gap roller is EPD.
M (ethylene propylene rubber), hardness 70 ° (JIS-
The scale of the discharge roller is CR (chloroprene rubber) and the hardness is 70 °. Generally CR is E
Wear resistance is higher than PDM, but EPDM is C
Compared to R, it has higher ozone resistance and is more resistant to the effects of ink mist from the inkjet head.

By the way, in the structure of this embodiment, 10 continuous sheets (1 form 11 inches wide, 16 inches wide) are used.
The amount of abrasion of the discharge roller when the sheet is conveyed by 0000 sheets is 0.
It was 041 mm. On the other hand, when the discharge roller has the same EPDM and hardness of 70 ° as the gap roller, the abrasion amount of the roller is 0.057 mm after 79,000 sheets are conveyed, and the relative speed is lower than that of the gap roller and the paper jam occurs. The diameter of the discharge roller at that time was the same as the diameter of the gap roller.

(Second Embodiment) Next, a second embodiment of the ink jet recording apparatus to which the present invention is applied will be described with reference to the drawings.

The members having the same functions and mechanisms as those in the above-mentioned embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the above-described embodiment, the discharge roller 14 is a grooved roller in order to prevent defective discharge, and the material of the roller is different from the gap roller 13 in order to prevent wear deterioration due to continuous paper. The invention is not limited to this. As shown in FIG. 7, the discharge roller 14 is
A plurality of spurs 14a, 14 are provided on the same rotating shaft.
It is also possible that only the paper discharge roller 14 that is in pressure contact with both b is grooved, and the other paper discharge roller that is in pressure contact with only the spur 14a is cylindrical. The grooved roller has a small contact area with the paper due to the groove, which promotes wear. The minimum discharge rollers required for the discharge stack are grooved, and the remaining rollers are cylindrical, which reduces the wear of the discharge rollers as a whole and prevents the occurrence of paper jams due to wear deterioration. it can.

[0045]

As described above, according to the present invention,
A first ejecting unit and a second ejecting unit are provided on a downstream side of the conveying unit that conveys the recording medium toward the recording unit in the recording medium conveying direction, and the first ejecting unit urges the recording medium to be separated from the recording unit. Since the recording medium of the fixed length is discharged, the recording surface of the recording medium of a fixed length can be prevented from being soiled, and the second discharging means has excellent abrasion resistance. It is possible to reduce the abrasion of the second discharging means due to the sticking and prevent the occurrence of jam of the recording medium.

[Brief description of drawings]

FIG. 1 is an external perspective view showing an embodiment of an inkjet recording apparatus of the present invention.

FIG. 2 is a cross-sectional view showing a main configuration of the automatic paper feeder of the inkjet recording apparatus of FIG.

FIG. 3 is a main-portion cross-sectional view showing a state where a cut sheet is selected.

FIG. 4 is a main-portion cross-sectional view showing a state where continuous paper is selected.

FIG. 5 is a cross-sectional view showing a configuration of a paper feed drive system of a conventional inkjet recording apparatus.

FIG. 6 is a cross-sectional view showing a conveyance state of a lower end portion of a cut sheet of a conventional inkjet recording device.

FIG. 7 is a schematic front view showing an embodiment of another ink jet recording apparatus of the present invention.

[Explanation of symbols]

3 ... Pin feed tractor 5 ... Pinch roller holder 10 ... Conveying roller 11 ... Pinch roller 12 ... Needle roller 13 ... Gap roller 13a, 14a, 14b ... Spur 14 ... Paper discharge roller 16 ... Auxiliary roller 20 ... Inkjet head 24 ... Platen 35 ... Paper feed port 223 ... Needle roller holder 241 ... Release shaft 245 ... Pinch roller spring 246 ... Needle roller spring 248 ... Auxiliary roller spring 251 ... Release lever

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[Procedure amendment]

[Submission date] April 18, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Name of item to be corrected] Figure 7

[Correction method] Change

[Correction contents]

FIG. 7

Claims (11)

[Claims] 1. A recording means for ejecting ink to a recording medium for recording in response to an image signal, and a first conveying means for conveying a recording medium of a fixed length toward the recording means. In an inkjet recording apparatus provided, a first ejecting unit located downstream of the recording unit in the recording medium conveying direction and a second ejecting unit located downstream of the first ejecting unit in the recording medium conveying direction are provided. The ink jet recording apparatus is characterized in that the first ejecting unit ejects the paper by urging the rearmost portion of the recording medium from the recording unit. 2. A recording means for ejecting ink to a recording medium to perform recording in response to an image signal, and a first conveying means for conveying the recording medium toward the recording means.
An ink jet recording apparatus comprising: a second transport unit for transporting a long recording medium to the first transport unit; and a first discharging unit located downstream of the recording unit in the recording medium transport direction. And a second ejecting unit located downstream of the first ejecting unit in the recording medium conveying direction, the first ejecting unit biasing a part of the recording medium in a direction of separating it from the recording unit. An inkjet recording device that discharges paper. 3. The ink jet recording apparatus according to claim 1 or 2, wherein the second ejecting unit is configured to have better abrasion resistance than the first ejecting unit. 4. The ink jet recording apparatus according to claim 1, wherein the first discharging means and the second discharging means are accelerated with respect to a conveying speed of the first conveying means. Further, the ink jet recording is characterized in that the speed increasing ratio of the second discharging means to the conveying speed of the first conveying means is set to be larger than the speed increasing ratio of the first discharging means to the conveying speed of the first conveying means. apparatus. 5. The ink jet recording apparatus according to any one of claims 1 to 4, wherein the first ejecting means and the second ejecting means have rollers and the materials of the rollers are different. apparatus. 6. The ink jet recording apparatus according to claim 1, wherein the second discharging unit has a roller, and the roller is in a direction orthogonal to a rotation direction for discharging the recording medium. An ink jet recording apparatus characterized in that a groove is formed in parallel with. 7. The ink jet recording apparatus according to claim 5 or 6, wherein the first ejecting unit has a spur facing the roller on the upstream side in the recording medium conveying direction,
The ejecting means has a pair of spurs facing the roller on the upstream side and the downstream side in the recording medium conveyance direction. 8. The ink jet recording apparatus according to claim 2, wherein the second conveying unit is a pin feed tractor that conveys continuous paper. 9. The ink jet recording apparatus according to claim 2, wherein the elongated recording medium is conveyed while being in contact with the outer peripheral surface of the second ejecting unit. 10. The ink jet recording apparatus according to claim 1, wherein the recording means includes an electrothermal converter for generating thermal energy for ejecting ink. Inkjet recording device. 11. The ink jet recording apparatus according to claim 10, wherein the recording unit ejects the ink from the ejection port by utilizing film boiling generated in the ink by the thermal energy applied by the electrothermal converter. Characteristic inkjet recording device.