JPH03133646A - Recording paper feed processor in ink jet printer - Google Patents

Abstract

PURPOSE:To uniformly dry a whole recording medium including the wetted part of the recording paper in feeding even if said part has become wet to a large extent by providing a control means which controls the feed speed of a feed means in accordance with a pixel density after the elapse of a time required for the appropriate part of the recording paper to reach a drying means from a recording writing means. CONSTITUTION:An intermediate paper discharge roller provided just after a follower roller 22 consists of an intermediate roller 63 provided with thin-wall cylindrical parts at the opposite ends thereof and thin indented rollers 66 coming into contact with said thin-wall cylindrical parts. Therefore, a recording paper S becoming wet because of the application of an ink writing processing is guided to a paper discharge guide plate 61 in the state that it is loosely clamped between the both rollers, fed into a hot-air drying unit 90, and discharged onto a paper discharge tray 74 by paper discharge rollers 69, 72. A drive circuit 57 controls a drive motor 58 in accordance with a high-pixel density area and a pixel density. An interval of paper feeding is extended in accordance with the extent of the pixel density before the high-density area is passed through the hot-air drying unit 90 after the elapse of a timer T required for the appropriate part of the recording paper S to reach the hot-air drying unit 90.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a recording paper conveyance processing device used in an inkjet printer.

(Prior art) In-jet printers, which print by selectively discharging ink from multiple nozzles, are superior to other printers in that they can record and write on plain paper without generating noise and at low running costs. It's better than that.

However, on the other hand, this type of printer usually uses water-soluble ink in order to ensure stability in writing, so the recording paper contains moisture and becomes easily rippled or easily torn. This has the disadvantage of making subsequent transportation difficult.

Of course, to solve this problem, a hot air generator installed in the printer can be used to blow hot air onto the recording paper on the platen to dry the ink without giving the recording paper any bad effects. JP-A-54-156536, which blows hot air directly onto the recording paper surface to dry the ink at the same time as writing.
This method has been proposed in US Pat. No. 4,340,893. However, characters and figures written on recording paper usually have partial shading, and sometimes a solid black image is written, so a hot air dryer is simply installed on the lower side of the dot image writing area. However, it is not possible to dry the large areas of pixels and density sufficiently, especially in page printers that are configured to print at high speed. Various problems occur during transportation.

(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned problems, and its purpose is to ensure reliable drying and accurate drying of recording paper regardless of the pixel density to be recorded. An object of the present invention is to provide a new paper feeding device for an inkjet printer that enables paper feeding.

(Means for Solving the Problems) That is, the present invention is a recording paper conveyance processing device for an inkjet printer to achieve the above-mentioned problems. a recording paper drying means disposed on the downstream side of the recording writing means; and a conveying means for transporting the recording paper from the upper side of the recording writing means to the downstream side of the recording writing means via the drying means; By providing a control means that determines the pixel density of the dot image to be written and controls the feeding speed of the conveyance means according to the pixel density after the time elapses from the recording/writing means to the drying means, a part of the dot image to be written can be Even if there is a portion with a high pixel density in the recording paper and the recording paper is greatly wetted, the entire recording medium including this portion is uniformly dried and transported.

(Example) Therefore, the illustrated embodiment will be explained below.

FIG. 1 shows the entire structure of a recording paper transport bag for an inkjet printer according to an embodiment of the present invention, and FIGS. 2 and 3 show details of the main parts thereof.

This recording paper conveyance processing device is roughly divided into a paper feeding section 10 having a fanfold paper feeding path and a cut paper feeding path, a paper feeding section 20 disposed in a recording writing section, and a recording paper S
and a paper discharge section 60 that discharges the paper while drying it.

In the paper feed section 10, a paper feed table 12 is provided which is biased upward by a hopper spring 1 and is movable up and down, and constantly feeds the topmost recording paper S among the stacked recording papers S. roller 13
Also, on the paper feed guide plate 14 extending from the paper feed roller 13 to the gate roller 21, which will be described later, there is a separation claw opening/closing lever 17 operated by a control lever (not shown). And this lever 171
A separating claw 16 that can be raised and lowered from this is provided, and a fanfold paper sheet facing the casing paper feed port 3 provided on the front plate 2 of the printer main body 1 (FIG. 9) is provided above the paper feed table 2. A guide plate 19 for insertion is provided, and the paper is configured to be directly fed to the gate roller 21 by the tractor 15.

On the other hand, in the paper conveyance section 20 following this, a gate roller 21 connected to a driving force transmission mechanism (not shown) is disposed on the upper side of the paper conveyance section 20 so as to sandwich the travel path of a carriage 80, which will be described later. A driven roller 22 is disposed immediately after the gate roller 21, and is configured to rotate at the same circumferential speed via a paper feeding belt 23 suspended between it and the gate roller 21. The paper feed belt 23 has an idler 2 supported on one end of an idler lever 26.
5 comes into contact with the platen 46 immediately below, and a tension spring 27 acting on the idler lever 26 applies constant tension at all times.

Reference numeral 29 denotes a paper presser roller lever which is swingably supported on a fulcrum 9 above the above-mentioned gate roller 2;
This paper presser roller lever 29 is used to transfer the recording medium fed thereto by the frictional force between the paper feed belt 23 formed around the outer periphery of the gate roller 21 and the paper presser roller 32, such as a cut sheet or an envelope. The contact pressure between the paper feed belt 23 and the paper pressing roller 32 can be changed depending on whether the paper is old paper or the fan 2 paper is fed by the tractor 15. That is, a strong pressing spring 33 is attached to the end of the upper arm 29a of the paper presser roller lever 29, and is attached to the upper edge of the upper arm 29a. In this case, a cam 34 that rotates the lever 29 clockwise in the drawing is in contact with the pressing spring 33, and as shown by the solid line in FIG. 33 directly acts on the lever 29, the paper pressing roller 32 supported in the arcuate groove 30 at the lower end of the lower arm 29b is strongly pressed against the paper feed belt 23, and as shown by the two-dot chain line, When the cam 34 rotates clockwise in the figure to release the biasing force of the strong presser spring 33, the paper presser roller 32 is moved by the other end 35 of the weak torsion coil spring 31 whose one end is fixed to the paper presser roller lever 29. is configured to be pressed onto the paper feed belt 23 with a weak force.

On the other hand, 37 is a vapor pail that comes into contact with and separates from the paper feed belt 23 on the driven roller 22, and this paper pail 37 has a plate-shaped jagged roller with jagged edges on the shaft 3.
The structure is such that a plurality of them are fixed at intervals of 6. The vapor pail lever 38 that supports the vapor pail 37 at one end has its base end fixed to a support shaft 39 supported on the lower side of the driven roller 22, as shown in FIG. Binion 4 meshing with sector 40
1, the vapor pail 37 is transferred to the paper feed belt 23 immediately before it passes over the rear end of the recording paper S or over the gate row 521.
It is configured so that the recording paper S is fed out by being pressed against the top.

By the way, the above-mentioned gate roller 21 and driven roller 22
The paper feeding mechanism, which mainly includes a paper feeding belt 23 suspended over these, is configured to perform an intermittent feeding operation at a speed corresponding to the pixel density of characters, figures, etc. written on the recording paper S. There is.

That is, in this inkjet printer, as shown in FIG. 10, recording information to be written for one page, for example, sent from a host computer 50 is stored in a buffer 52 via an interface 51. Then, the control circuit 53 outputs control signals to the paper feed drive circuit 55, head drive circuit 56, and heater drive circuit 57 according to the input signal from here and a preset program, and controls the drive motor 58 and printing. The head 81, heater 93, and fan motor 95 are configured to perform predetermined paper feeding, recording writing, and recording paper drying operations, but in general, this printer has a buffer 52 and a print pattern analysis circuit 54. The recording write information is analyzed here, and if there is a part with a large pixel density, the pixel density is determined in both the main scanning direction and the sub-scanning direction. The degree and area of the large portion are outputted as numerical data to the control circuit 53, and after M pages have elapsed while the recording paper is being conveyed from the print head to the hot air drying unit, the length corresponding to the above area is preliminarily set. The driving motor 58 is controlled to transport the recording paper S intermittently at intervals corresponding to the set pixel density.

Returning again to FIG. 3, reference numeral 43 denotes a guide plate on the recording paper carry-in side disposed on the upper side of the platen 46, and the starting end of this carry-in guide plate 43 is connected to the paper feed guide plate 14 extending from the paper feed roller 13 The end is located at the confluence of the guide plate 19 for inserting fanfold paper, and the end is located just before the printing section that connects to the platen 46. The plate 45 remains in contact due to its own elasticity.

On the other hand, the platen 46 disposed directly below the travel path of the gear nodge has its base end fixed to a fulcrum shaft 47 provided on the lower side, and serves as the above-mentioned manual operation lever for operating the separation claw opening/closing lever 17. A lever (not shown) connected via a link is configured to lower and retract to a position indicated by a two-dot chain line in the figure, thereby allowing thick envelopes to pass through.

On the other hand, in the sheet discharge section 60, a pair of intermediate sheet discharge roller shafts 62, 65 are arranged on the downstream side adjacent to the driven roller 22. A plurality of short intermediate paper ejection rollers 63 made of an elastic material are fixed at intervals to one of the intermediate paper ejection roller shafts 62 disposed below the paper ejection guide plate 61, and each of these rollers 63 has a As shown in FIG. 5, thin-walled cylindrical portions 64, 64 with a slightly smaller diameter are integrally formed at both ends thereof, and a thin plate-shaped jagged roller 66.64 is fixed to the other intermediate paper ejection roller shaft 65. 66 to these thin-walled cylindrical portions 6
4.64, so that the wet recording paper S can be ejected without applying excessive force.

On the other hand, reference numerals 68 and 71 denote a pair of paper ejection roller shafts disposed on the downstream side of the hot air drying unit 90, which will be described later.
As shown in FIG. 6, a plurality of paper ejection rollers 69 made of an elastic material are fixed to the other paper ejection roller shaft 71, and a thin wall wrapper 7o is provided at only one end. A thin plate-shaped jagged roller 72 is fixed in such a manner that the position is slightly shifted in the axial direction with respect to the part 70, and the shape is slightly matched in the radial direction. The sheet is configured to form a wave, and the resulting stiffness causes the sheet to protrude flatly and to be sent to the sheet discharge tray 14.

Reference numeral 80 in the drawing denotes a carriage that runs along two guide rails 81 and 81 suspended by the upper force of the printing section so as to be perpendicular to the recording paper conveyance direction. In addition to the inkjet head 82 that ejects ink onto the recording paper S from a single nozzle, there is also a duct-integrated fan 83 that blows away paper powder or dust adhering to the recording paper S, and an inkjet head 82 located in front of the head 82 in the running direction. A paper presser lever 86 is provided to press the recording paper S portion.

That is, as shown in FIG. 7.8, a duct-integrated fan 83 having an inverted V-shaped outlet is provided on the lower side of the carriage 80 in the paper conveyance direction, and the The air blown down is distributed to the left and right to avoid the head 82 along the vertical baffle plate 84 provided, and the air is directed toward the recording paper S.
It is configured to blow away paper powder etc. adhering to the surface of the recording paper S while guiding it along the surface to the other side.

On the other hand, a pair of solenoids 87 and 87 are provided on both sides of the carriage 80, as shown in FIG.
2a7j sandwich each of these solenoids 87.8
A pair of paper presser levers 86 and 86 are swing-driven by 7.
is pivotably supported, and alternately moves in a seesaw manner so that the tip 86a of the paper presser lever 86 located at the front in the traveling direction of the carriage 80 is lowered, while the tip of the paper presser lever 86 located at the rear in the travel direction is raised. By swinging, the paper presser lever 86 holds the recording paper S portion in front in the running direction.
It is configured to print while being pressed against the surface of the platen 46 by the tip portion 86a of the platen 46.

In addition, on the lower surface of the upper side of the carriage 80,
A lifting regulating piece 88 is provided with a slight gap between it and the tip of the holding plate 45, and prevents lifting of the holding plate 45 when a thick recording medium such as an envelope is fed into the printing section. It is designed to suppress.

On the other hand, the reference numeral 90 in the figure indicates the recording paper S after the record writing process has been completed.
As shown in FIG. 9, this unit 90 is supported by the side plates 4.4 of the printer body and is positioned opposite to the paper ejection guide plate 61. It is composed of a duct 91 that moves, a lid 93 disposed inside the duct 91, and a fan 94 disposed at a suitable position within the printer body 1. The guided air is heated by a heater 93, and the heated air is blown onto the surface of the recording paper S through a large number of small blow-off holes 92 provided on the lower surface of the duct 91 and facing downward in the paper transport direction. It is configured as follows.

Next, the recording paper conveyance processing operation of the above-mentioned mounting will be explained.

In the case of the paper feed mode for paper sheets, the separation claw located at paper feed section]0 is opened and closed, and the bar 17 is lowered by a manual operation lever (not shown), and the separation claw 16 is shown by the solid line in FIG. The platen 46 is positioned at the front end of the stacked recording sheets S, and the platen 46 is pulled up by a lever connected to a manual operation lever via a link mechanism so as to be flush with the paper carrying guide plate 43. The pressing force is released, a strong pressing spring 33 is applied to the paper pressing roller lever 29, and the paper pressing roller 32 at the lower end of the lever 29 is strongly pressed against the paper feeding belt 23.

In this state, when the paper feed roller 13, which has started rotating in response to a paper feed signal, feeds out the recording paper S on the paper feed table 12, the uppermost recording paper S is separated by the separation claw ]6, and the paper feed guide plate 14 and the gate roller 21 guided by the loading side guide plate 43.
The paper reaches the top, where it passes through the opening of the paper feed belt 23 and the paper presser roller 32 that is in strong pressure contact with it, and is sent to the printing section.

The recording paper S fed into the printing section while being lightly pressed by the presser plate 45 is pressed onto the surface of the platen 46 by a paper presser lever 86 located at the front of the main carriage 80 in the running direction, and the information to be recorded is Characters, figures, etc. corresponding to the information are written. Also, during this writing, the carriage 8o
The upper duct-shaped fan 83 blows air from an inverted V-shaped outlet to both sides of the recording paper S and directs it to the other side to remove paper dust and dirt attached to the recording paper S. Blow away dust, etc. to prevent paper powder, etc. from adhering to the nozzle.

On the other hand, at the beginning of paper feeding, the paper pail lever 38
is driven by the pinion 4 which engages with the sector 40 and rotates upward, and the paper pail 37 supported at its tip
Since the paper feed belt 23 moves MM, the recording paper S that has undergone the recording/writing process passes under the paper pail 37 that is being pulled up and is sent to the paper discharge section 60 without disturbing the dot image.

By the way, as described above, the intermediate paper ejection roller disposed immediately after the driven roller 22 has thin cylindrical portions 64 and 64 at both ends.
an intermediate roller 63 with a thin-walled cylindrical portion 64 .
64, the recording paper S, which has been dampened due to the ink writing process, is loosely sandwiched between these rollers and written on the surface by the thin jagged roller 66. The dot image is guided without being disturbed by the sheet discharge guide plate 61 and sent into the hot air drying unit 90, where it undergoes the necessary drying process with hot air and is discharged by the sheet discharge rollers 69, 72. It is discharged onto the tray 74.

This operation continues, and just before the trailing edge of the recording paper S passes over the gate roller 21, a paper edge detection sensor (not shown) disposed here detects this state, and the detection output detects this state. 41, lower the paper hail lever 38 via the sector 40, bring the vapor pale 37 at the tip into contact with the paper feed heald 23, and move the recording paper S, which has been cut off from being conveyed by the gate roller 21, to the driven roller 22.
and the thin jagged rollers of the paper pail 37, the hot air drying unit 90 can be used without adversely affecting the recorded and written image.
send it towards.

By the way, when writing this dot image record, if the density of pixels constituting a figure etc. is extremely high, the corresponding part of the recording paper S that has received a large amount of ink droplets may become extremely wet. Large undulations or swelling may occur, but such a situation is quickly detected by the print pattern disassembly circuit 54 which receives recorded information from the buffer 52 and outputs the detected contents to the drive circuit 55. For this reason, the drive circuit 57
controls the drive motor 58 according to the area with high pixel density and the pixel density, and after the time T has elapsed until the corresponding part of the recording paper S reaches the hot air drying unit 90, the area with high pixel density is Until the paper passes through the hot air drying unit 90, the paper feeding interval is extended depending on the level of pixel density to increase the time required for hot air drying to ensure that this portion is completely dry.

On the other hand, when printing on envelopes stacked on the paper feed tray 12, the separation claw opening/closing lever 1 is operated by a manual operation lever.
7, the separating claw 16 is removed from the tip of the envelope, and the platen 46 is lowered to the position shown by the two-dot chain line in FIG. Evacuate.

As a result, the envelopes pulled out by the paper feed roller 13 are
The paper is guided by the slope 14a provided on the front side of the paper feed plate 14 and conveyed to the gate roller 21, and is sent to the printing section while being subjected to strong friction between the paper presser roller 32 and the paper feed heald 23. As mentioned above (when printing on envelopes, the platen 46 has already descended, so when the envelopes are fed here, the sealing spatula easily passes through the gate between the platen 46 and the above). Accurate printing is done on this side, just like on cut paper.

In addition, when printing on fanfold paper using the tractor 15, the cam 34 is rotated to the position indicated by the two-dot chain line in FIG. 3, and the paper presser roller lever 29 is rotated clockwise in the figure. to release the biasing force of the strong spring 33 and press the paper presser roller 32.
is brought into pressure contact with the paper feed belt 23 by a weak spring 35, and the fanfold paper is fed into the printing section.

(Effects) As described above, according to the present invention, an inkjet printer equipped with a drying means is provided with a conveying means that changes the feeding speed according to the degree of pixel density, so that the dots to be written can be Even if there is a part of the image with a high pixel density and the recording medium is greatly wetted, the entire recording medium including this part can be uniformly dried. Moreover, a plate-shaped roller having a single notch on the circumference is disposed between the writing means and the drying means, and the roller is rolled after the trailing edge of the recording medium passes through the portion located on the upper side of the writing means. Since only the dots are brought into contact with the recording medium, the dot image which has just been written is not adversely affected, and even the recording medium which has become stiff due to wetness can be reliably fed to the drying means.

[Brief explanation of the drawing]

Fig. 1 is an overall view of a device constituting an embodiment of the present invention, Figs. 2 and 3 are enlarged views showing the main parts of the same device, Fig. 4 is a view showing the paper pail mechanism, and Fig. 5 is a diagram showing the paper pail mechanism. Fig. 6 is a cross-sectional view showing the roller on the paper ejection side, Fig. 7 is a perspective view showing an outline of the carriage, and Fig. 8 (aXb) is a state in which paper dust, etc. is removed by the duct-integrated fan. An explanatory diagram showing
FIG. 9 is an external view of the inkjet printer mainly showing the hot air drying unit, and FIG. 10 is a diagram showing the control circuit of the printer. 13...Paper feed roller 21...Gate roller 22...Followed roller 23...Paper feed heald 29...Paper presser roller lever 32...Paper presser roller 37... ... Paper pail 38 ... Paper pail lever 63 ... Intermediate paper ejection roller 64 66 ... Giza roller 69 70 ... Thin trumpet-shaped portion 72 80 ... Carry ring 82 83. ...-Duct-integrated fan 86 ... Paper presser lever 90 ... Hot air drying unit ... Thin-walled cylindrical part ... Paper ejection roller ... Jagged roller ... Head

Claims (1)

[Claims] 1. Recording and writing means for ejecting ink droplets to form a dot image on a recording medium according to input information, and a recording medium drying means disposed on the downstream side of the recording and writing means. , a conveying means for transporting the recording medium from the upper side of the recording/writing means to the lower side thereof via the drying means; and a conveying means for transporting the recording medium from the recording/writing means to the drying means by determining the pixel density of a dot image to be written. A recording paper conveyance processing device for an inkjet printer, comprising a control means for controlling a feed speed of the conveyance means in accordance with the pixel density after a period of time has elapsed. 2. Between the recording and writing means and the drying means, the trailing edge of the recording medium passes through the upper side of the recording and writing means of the conveyance means and then comes into contact with the dot image forming surface of the recording medium to dry the recording medium. 2. The recording paper conveyance processing device for an inkjet printer according to claim 1, further comprising a conveying roller. 3. Claim 1, wherein a thin cylindrical body in contact with the back surface of the recording medium and a plate-shaped roller having serrations on the circumferential surface in contact with the dot image forming surface are disposed between the recording/writing means and the drying means.
or 2. The recording paper conveyance processing device for an inkjet printer according to 2.