JP2003063713A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recorder which can suppress any rise of a rear end part of a paper to be recorded when the paper is discharged. SOLUTION: The ink jet recorder 1 comprises a platen 30 to support the paper P in a printing area, paper discharge roller pairs 36 having a paper discharge roller 9 located below the paper P discharged on the downstream side in the paper carrying direction of the platen 30 and a spur roller 32 which is elastically urged to a paper discharge roller 9 while holding the paper P, and an intermediate spur roller 31 which is disposed in an upwardly immobile manner between the printing area and the paper discharge roller pairs 36. The axis of the spur roller 32 is located in the direction of the upper platen with respect to the axis of the paper discharge roller 9, and a nip point A at which the paper discharge roller pairs 36 are brought into contact with the paper P and a contact point B at which the intermediate spur roller 31 is brought into contact with the paper P are located lower than the highest surface of the platen 30 and on the horizontal surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet recording apparatus, and more particularly to an inkjet recording apparatus characterized by a recording material conveying mechanism.

[0002]

2. Description of the Related Art An ink jet recording apparatus moves a recording head in a main scanning direction on a platen and feeds a recording material line by line in a direction orthogonal to the main scanning direction to eject ink from the recording head. And print. Such an ink jet recording apparatus is composed of a paper feeding unit, a recording unit, and a paper discharging unit. First, the recording material is conveyed by the pair of conveying rollers provided in the sheet feeding section and is fed to the recording section. Next, in the recording area of the recording unit (a predetermined position on the upper surface of the platen), ink is ejected from the recording head to form an image. Finally, the recording material on which an image has been formed is discharged by a pair of discharge rollers provided in the discharge unit.

[0003]

However, depending on the posture of the recording material in the portion discharged from the paper discharging portion, when the trailing end of the recording material comes off (disengages) from the pair of conveying rollers of the paper feeding portion. There is a problem that it causes a rise.

This is because when the recording material is removed from the pair of conveying rollers, the recording material is conveyed only by the pair of discharge rollers, and the recording material is discharged due to the weight of the discharged recording material. This occurs because the pair of paper ejection rollers is expanded and bent in an upward convex shape, causing the trailing edge to rise, and the distance (distance) between the recording head and the recording material deviates from the preferable range for printing. This causes deterioration of print quality and stains due to contact with the recording head.

In order to solve this problem, it is conceivable to arrange the pair of paper discharge rollers so as to be inclined so that the recording material is discharged obliquely upward. In the case of handling a recording material, it is necessary to increase the pressing force (nip pressure) of the discharge roller pair against the recording material in order to eliminate the influence of the weight of the recording material.

However, in many cases, a member composed of a large number of protrusions called a spur is used on the recording surface side of the discharge roller pair, and if the nip pressure is excessively increased, the recording paper will have holes. However, after all, it was not possible to raise the nip pressure necessary to make all the discharge directions of various recording materials obliquely upward.

Therefore, the present invention provides an ink jet recording apparatus which can prevent the trailing end portion of the recording material from being lifted up at the time of discharging the sheet and can obtain high printing quality.

[0008]

The present invention will be described below. In addition, in order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are added in parentheses, but the present invention is not limited to the illustrated forms.

According to the first aspect of the invention, the printing area (YY ')
At 30, a platen (30) for supporting the recording material P, a discharge roller (9) disposed below the recording material (P) discharged downstream of the platen in the recording material conveyance direction, and the recording material. A pair of discharge rollers (3) having a spur roller (32) which is elastically biased against the discharge roller with a material sandwiched therebetween.
6), an intermediate spur roller (31) disposed immovably in the upward direction between the printing area and the pair of discharge rollers,
It is characterized by being composed of.

According to the present invention, the intermediate spur roller, which is arranged so as not to move upward, is set in the printing area (recording head 7).
By arranging the recording medium between the paper ejection roller pair and the paper ejection roller pair, the intermediate spur roller presses downward on the recording material that is bent in a convex shape to the upper side (recording head side) generated at the time of paper ejection. It is possible to discharge the recording material while maintaining the posture of the recording material by the intermediate spur roller and the discharge roller pair. This allows
It is possible to prevent the print quality from deteriorating and the contact with the recording head due to the gap between the recording head and the recording material deviating from the preferable range for printing.

According to a second aspect of the present invention, the nip point (where the shaft center of the spur roller is arranged in the upper platen direction with respect to the shaft center of the paper discharge roller, and the paper discharge roller pair contacts the recording material ( A), the contact point (B) where the intermediate spur roller and the recording material contact each other are arranged at a position lower than the uppermost surface of the platen. Further, the invention of claim 3 is characterized in that the intermediate spur roller is arranged such that the nip point and the contact point are located on a horizontal plane.

According to the present invention, the nip point where the discharge roller pair contacts the recording material and the contact point where the intermediate roller contacts the recording material are located at a position lower than the uppermost surface of the platen and on the horizontal plane. By being placed so that
The influence of the self-weight of the recording material is eliminated, and lifting of the trailing edge of the recording material during paper ejection is suppressed by the intermediate spur roller and the pair of paper ejection rollers, and the spur roller that is elastically biased is covered. It is possible to eject the recording material while pressing the surface of the recording material with the optimum nip pressure. As a result, the distance between the recording head and the recording material can be maintained within a specific suitable range, and high printing quality can be obtained.

According to a fourth aspect of the present invention, the intermediate spur rollers are arranged alternately with the paper discharge roller pairs in a direction orthogonal to the recording material conveying direction.

According to the present invention, the recording material is made to lie parallel to the lower surface of the recording head while suppressing the generation of wrinkles on the upper surface of the platen by making the recording material undulate on the platen at a predetermined height. Therefore, high print quality can be obtained.

[0015]

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.

FIG. 1 is a structural diagram of an ink jet recording apparatus,
2 is a perspective view of a printing unit of the inkjet recording apparatus, and FIG. 3 is a perspective view of the inkjet recording apparatus.

First, the overall structure of the inkjet recording apparatus 1 with a communication function will be described.

The ink jet recording apparatus 1 includes an operation unit 2, a paper feeding unit 3, a printing unit 4, a paper discharging unit 5, and a reading unit 6.
With.

A recording material P (paper, OHP sheet, etc.) is inserted into the paper feed tray 3a of the paper feed section 3 and printed by the buttons 2b, 2b ... 2b provided on the operation panel 2a of the operation section 2. When the instruction is given, the uppermost sheet of the recording material P is separated by the sheet feeding roller 3b of the sheet feeding unit 3. The separated recording material P is guided to the printing unit 4 by the transport roller 8. The recording head 7 reciprocates with respect to the recording material P guided to the printing unit 4, and the recording head 7 responds to the image signal.
A predetermined ink is ejected from and printed. Then, the printed recording material P is ejected from the paper ejection tray 5a (paper ejection unit 5) by the paper ejection roller 9 of the paper ejection unit 5.

On the other hand, the document inserting section 6 provided in the reading section 6
When a document is inserted from a, the document is read by the document reading unit 6b, and the read document is transmitted as data through the telephone line. The original is the original output section 6c.
Will be ejected more. In addition, the inkjet recording device 1 is
It also has a function of converting data transmitted via a telephone line into an image signal. This image signal is printed on the recording material P in the printing unit 4, and the printed recording material P is ejected. In this way, the inkjet recording apparatus 1 also has a function as a facsimile apparatus. The inkjet recording apparatus 1 also has a copying function. When you insert the original you want to copy from the original insertion section 6a,
The document is read by the document reading unit 6b, the read document data is printed via the printing unit 4, and the printed recording material P is ejected from the paper ejection unit 5. At that time, the document used for reading is discharged from the document discharging unit 6c.

The printing unit 4 includes ink cartridges 10 filled with four color inks of cyan, magenta, yellow, and black, and a head unit 11 having a recording head 7 for printing on a recording material P. A carriage 12 on which the ink cartridge 10 and the head unit 11 are mounted, a drive unit 13 that moves the carriage 12 in a linear direction, and a conveyance roller that extends in the reciprocating direction of the carriage 12 and is arranged to face the recording head 7. 8, the purging device 15, and the ink sensor 16
And are equipped with.

Three partition plates are erected on the mounting portion 11a of the head unit 11 so as to stand between the pair of side covers 11b formed on both sides of the mounting portion.
Is divided into four ink cartridge mounting portions via each partition plate. Four ink cartridges 10 filled with cyan ink, magenta ink, yellow ink, and black ink are mounted in this mounting portion. In addition,
The fact that the black ink cartridge has a large volume with respect to each ink cartridge filled with the other three colors of ink is due to the fact that the frequency of use of the black ink is higher than that of the other colors. Is.

The drive unit 13 includes a carriage shaft 17 arranged at the lower end of the carriage 12 and extending in parallel with the conveying rollers 8, a guide plate 18 arranged at the upper end of the carriage 12 and extending in parallel with the carriage shaft 17, and the carriage thereof. Two pulleys 19 and 20 arranged between the shaft 17 and the guide plate 18 at both ends of the carriage shaft 17.
And an endless belt 21 stretched between the pulleys 19 and 20.

When one of the pulleys 20 is rotated forward and backward by driving a carriage motor (CR motor) 22, the carriage 12 joined to the endless belt 21 is rotated along with the forward and reverse rotation of the pulley 20. Along the carriage shaft 17 and the guide plate 18, it is reciprocated in a linear direction.

The purging device 15 is provided on the side of the conveying roller 8 and is arranged so as to face the recording head 7 when the head unit 11 is in the reset position. The purging device 15 covers a plurality of nozzles (not shown) of the recording head 7, a purge cap 23 that abuts against an opening surface of the nozzle, a pump 24, and a cam 25.
When the head unit 11 is in the reset position, the nozzles of the recording head 7 are covered with the purge cap 23, and defective ink containing bubbles and the like accumulated inside the recording head 7 is provided. The recording head 7 is recovered by the suction of the pump 24 by driving the cam 25. The sucked defective ink is stored in the ink storage unit 26.

A wiper member 28 is disposed adjacent to the purging device 15 at a position on the conveying roller 8 side of the purging device 15. The wiper member 28 is formed in a spatula shape and wipes the nozzle forming surface of the recording head 7 as the carriage 12 moves. Cap 27
Covers a plurality of nozzles of the recording head 7 that is returned to the reset position when printing is completed in order to prevent the ink from drying.

The ink sensor 16 is a sensor for detecting the presence / absence of an ink cartridge and the presence / absence of ink in the ink cartridge. Near the end of the drive unit (Fig. 1
Is provided on the left side of) and includes an infrared light emitting element and an infrared light receiving element (not shown). The light emitting surface of the infrared light emitting element and the light receiving surface of the infrared light receiving element are inclined at an angle similar to that of the inclined portion of the ink cartridge which is inclined at about 20 degrees,
Moreover, it is obliquely arranged at an angle of approximately 10 degrees in the horizontal direction with respect to the inclined portion of the ink cartridge. The light emitted from the infrared light emitting element to the ink cartridge is
The reflected light is received by the infrared light receiving element. The presence or absence of ink in the ink cartridge is detected based on the amount of the received reflected light.

Next, with reference to FIGS. 4 to 6, a recording material transporting mechanism will be described. FIG. 4 is a structural diagram of a recording material conveying mechanism, and FIG. 5 shows a structure of a platen.
5A is a plan view, FIG. 5B is a view showing a relationship between a cross section and a spur roller, FIG. 5C is a front view of an intermediate spur roller,
FIG. 6 shows an arrangement for explaining the conveyance mechanism of the recording material in an easy-to-understand manner, and FIG. 6A is an arrangement view of spur rollers.
(B) is a layout view of intermediate spur rollers.

As shown in FIG. 4, a platen 30 is arranged below the recording head 7 so as to face it. This platen 3
A transport roller 8 for transporting the recording material P supplied to the paper feed tray 3a to the printing unit 4 is disposed on the upstream side (the right side in the drawing) of the recording material transportation direction 0. Also, the platen 30
The printing unit 4 is provided on the downstream side (left side in the drawing) of the recording material conveyance direction.
A paper discharge roller pair 36 for discharging the recording material P printed by is arranged. The paper discharge roller pair 36 includes a paper discharge roller 9 arranged below the discharged recording material P, and a spur roller 32 arranged above the recording material P and rolling in contact with the paper discharge roller 9. Equipped with. Further, an intermediate spur roller 31 for preventing the recording material P from floating is disposed between the platen 30 and the spur roller 32. A support member 35 is provided on the upper side of the platen 30 on the downstream side in the transport direction, and the intermediate spur roller 31 and the spur roller 32 are provided.
The paper discharge roller 9 is arranged at a predetermined position.

As shown in FIGS. 5 and 6, the platen 30
Is a horizontal portion 30a forming a flat surface in the portion facing the recording head 7, and first ribs 30b and second ribs 30c integrally projecting upward from the horizontal portion 30a. , Is provided. That is, this first rib 3
0b and the second rib 30c are arranged on the same plane. Further, the first rib 30b has a horizontal surface and an inclined surface 30d that is inclined from a position beyond the printing area YY ′ in the downstream direction of the recording head 7 connected to the horizontal surface,
30d ... 30d, and extend in the recording material conveyance direction. In addition, the second rib 30c forms a printing area YY 'in the horizontal direction and in the downstream direction of the recording head 7 continuous with the horizontal surface.
/ 4 inclined surfaces 30e, 30e ...
30e, and extends in the recording material conveyance direction. A plurality of the first and second ribs 30b and 30c are formed. The first and second ribs 30b and 30c allow the recording material P to run parallel to the lower surface of the recording head 7. Specifically, the first rib 30b is formed toward the intermediate spur roller 31, and the second rib 30c is formed toward the spur roller 32 so that they are located at the same position on the plane of the platen 30 in the recording material conveyance direction. It is arranged.
Further, the end of the platen 30 on the downstream side in the recording material conveyance direction has an inclined surface 30f inclined upward so as to scoop the tip of the recording material P. Further, both ends of the platen 30 in the direction orthogonal to the transport direction are fixed and positioned by the support members 33 and 33a. Further, the support members 33, 3
3a is fixed and positioned on the main frame. A fitting member 34 for fitting with the transport roller 8 is provided at one corner of the platen 30 on the upstream side in the recording material transport direction.

The transport roller 8 is formed by providing a protrusion 8b on the outer circumference of a shaft 8a. A preferred example of the protrusion shape 8b is ceramic coating.

The paper discharge roller pair 36 is arranged such that the line connecting the shaft center of the paper discharge roller 9 and the shaft center of the spur roller 32 is slightly inclined toward the recording head 7. Also, the discharge roller 9
Is formed by providing an elastic body on the outer circumference of the shaft. A preferable example of the elastic body is rubber.

The spur roller 32 is provided with a rotating body 37 having radially convex portions 37a adjacently arranged on the outer peripheral surface thereof, and is rotatably supported by a shaft 38 having elasticity. A spring is used as a preferable example of the shaft 38. This convex portion 37a
Presses the recording material P appropriately through the elastic force of the shaft 38 against the recording material P passing between the paper discharge roller pair 36. Further, a plurality of spur rollers 32 are provided with a certain interval in the direction orthogonal to the recording material conveyance direction of the platen 30.

The intermediate spur roller 31 is shown in FIG.
As shown in (c), a spur 40 having radially projecting portions 40a on its outer peripheral surface is integrally formed with a shaft 41, and is rotatably supported by a support member 35 fixed to the platen 30. The intermediate spur roller 31 presses the recording material P passing between the platen 30 and the discharge roller pair 36 downward, so that the recording material P when the recording material P is released from the conveying roller 8 is pressed. It is provided to prevent the rising of the. In the intermediate spur roller 31, the recording material P is conveyed by the conveyance roller 8.
Since the rear end of the recording material P is pushed down toward the platen 30 even after it is removed from the recording medium P, the shaft 41 having no elasticity is held so as not to move upward so as to withstand the reaction force from the recording material P. It is arranged. In addition, this intermediate spur roller 31
Are provided between the spur rollers 32.

The paper discharge roller pair 36 and the intermediate spur roller 31 have a nip point A where the paper discharge roller pair 36 contacts the recording material P and a contact point B where the intermediate spur roller 31 contacts the recording material P. Is arranged at a position lower than the height (uppermost part) of the second rib 30c of the platen 30. Further, the nip point A and the contact point B are arranged so as to be located on a horizontal plane.

Specifically, the center of the spur roller 31 and the spur roller 31 are closer to each other in the platen direction than the spur roller 32 at an interval such that the intermediate spur roller 31 does not come into contact with the recording head 7. Is arranged at a distance of about 5 mm from the axis of the platen, and the contact point B is arranged at a position about 0.3 mm lower than the height of the second rib 30c of the platen 30, so that the conveyance roller 8 is The trailing edge of the recording material P that has been removed is prevented from floating on the platen 30. In this case, the pressing force of the spur roller 32 does not move upward even if the trailing edge of the recording material P is insufficient to suppress the lifting of the trailing edge thereof. It is possible to prevent the rear end from rising.

The transport roller 8 and the paper discharge roller 9 are driven by a drive source (not shown).

According to the transport mechanism of the ink jet recording apparatus configured as described above, the platen 30 and the recording material P discharged to the downstream side of the platen 30 in the recording material transport direction.
Paper discharge roller pair 36 having a paper discharge roller 9 arranged below the recording material P and a spur roller 32 arranged above the recording material P.
And an intermediate spur roller 31 arranged between the platen 30 and the paper discharge roller pair 36, and the shaft center of the spur roller 32 is arranged in the upper platen direction with respect to the shaft center of the paper discharge roller 9. A position where a nip point A where the discharge roller pair 36 contacts the recording material P and a contact point B where the intermediate spur roller 31 contacts the recording material P are lower than the uppermost surface of the platen 30 (the horizontal plane of the second rib 30c). In addition, the nip point A and the contact point B are arranged on a horizontal plane so that the intermediate spur roller 31 does not move upward even when the recording material P comes off the paper discharge roller 9. Since the recording material P is held by the intermediate spur roller 31 and the paper discharge roller pair 36, the recording material P does not float on the upper surface of the platen, and the recording material P and the recording material P are not recorded. Print the spacing of head 7 It is possible to obtain a high print quality it is possible to maintain a suitable range of fit.

[0039]

As described above, according to the ink jet recording apparatus of the present invention, it is possible to prevent the trailing edge of the recording material from being lifted up at the time of discharging the sheet, and to obtain high print quality.

[Brief description of drawings]

FIG. 1 is a structural diagram of an inkjet recording apparatus according to the present invention.

FIG. 2 is a perspective view of a printing unit of the inkjet recording apparatus according to the present invention.

FIG. 3 is a perspective view of an inkjet recording apparatus according to the present invention.

FIG. 4 is a structural diagram of a recording material transporting mechanism of the inkjet recording apparatus according to the present invention.

5A is a plan view of the platen of the inkjet recording apparatus according to the present invention, FIG. 5B is a diagram showing a relationship between a cross section and a spur roller, and FIG. 5C is a front view of an intermediate spur roller.

6A and 6B are (a) an arrangement view of spur rollers and (b) an arrangement view of intermediate spur rollers for easy understanding of a recording material conveyance mechanism.

[Explanation of symbols]

A nip point B contact P Recording material 7 recording head 9 Paper ejection roller 30 Platen 31 Intermediate spur roller 32 spur roller 36 Ejection roller pair

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C056 EA04 HA30                 2C058 AB16 AB17 AC07 AC17 AE02                       AF25 AF31 DA11 DA34                 2C059 BB07 BB10 BB12 BB13 BB22                 3F049 AA01 CA31 DA11 DA12 LA01                       LB03

Claims (4)

[Claims] 1. A platen for supporting a recording material in a printing area, a sheet discharge roller disposed below the recording material discharged downstream of the platen in the recording material conveying direction, and the recording material sandwiched between the recording material. A discharge roller pair having a spur roller that is elastically biased against the discharge roller, and an intermediate spur that is immovably disposed between the print area and the discharge roller pair in an upward direction. An inkjet recording device comprising a roller and a roller. 2. The shaft center of the spur roller is arranged in the upper platen direction with respect to the shaft center of the paper discharge roller, and a nip point where the paper discharge roller pair and the recording material contact each other and the intermediate spur roller. The ink jet recording apparatus according to claim 1, wherein a contact point in contact with the recording material is arranged at a position lower than an uppermost surface of the platen. 3. The ink jet recording apparatus according to claim 2, wherein the intermediate spur roller is arranged so that the nip point and the contact point are located on a horizontal plane. 4. The intermediate spur roller is arranged alternately with the paper discharge roller pair in a direction orthogonal to the recording material conveyance direction.
The inkjet recording device according to item 1.