JP2002096513A - Recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recorder in which carrying accuracy of a plurality of discharge rollers is enhanced without causing a significant cost increase and carrying accuracy at the rear end part of a sheet is improved. SOLUTION: The recorder for recording a sheet P by means of a recording head 11 comprises a main carrying roller 13 for carrying the sheet P on the upstream side of the recording head 11 in the carrying direction, and a plurality of discharge rollers 16 and 17 for carrying the sheet P on the downstream side of the recording head 11 in the carrying direction wherein the second discharge roller 17 disposed on most downstream side in the carrying direction among the plurality of discharge rollers 16 and 17 has higher accuracy than the first discharge roller 16 disposed on the upstream side thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus having a plurality of transport means for transporting a sheet downstream of a recording means in a transport direction, and records an image on a recording sheet such as a facsimile, a copying machine, a printer, and the like. The present invention relates to a recording device that performs the recording.

[0002]

2. Description of the Related Art A conventional conveying apparatus for conveying a sheet such as a recording sheet in a recording apparatus such as an ink jet printer will be briefly described with reference to FIG.

As shown in FIG. 13, a sheet is nipped and conveyed by a main conveying roller 113 and a pinch roller 118, and recording is performed by a recording head 111 disposed downstream thereof. Then, the sheet on which recording has been performed is performed by the recording head 111.
A first spur roller 116 and a first spur 119,
And the second spur 120 and the second spur 120 discharge the paper. Here, by using two discharge rollers, the posture of the sheet is stabilized after the rear end of the sheet has passed through the nip portion between the main transport roller 113 and the pinch roller 118.

[0004]

Conventionally, there has been a difference in sheet conveyance accuracy between an area where a sheet is conveyed by a main conveyance roller and an area where a sheet is conveyed only by a discharge roller.
Text recording and graphic recording are mainly at the center of the output image, and the difference in transport accuracy is not a major problem.

However, with the recent improvement in image quality of a recording apparatus, there has been an increasing demand for recording a photographic image in the entire recordable area of a sheet, and the accuracy of sheet conveyance using only a discharge roller has been improved. It has been desired to reduce the difference with the transport accuracy.

For this reason, it is conceivable to improve the sheet conveyance accuracy using only the discharge rollers to the same level as that of the main conveyance roller. However, in the conventional configuration requiring a plurality of discharge rollers as described above, all the discharge rollers are required. A great deal of cost was required to improve the sheet conveyance accuracy of the rollers.

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording apparatus in which the conveyance accuracy at a plurality of discharge rollers is improved without significantly increasing the cost, and the conveyance accuracy at the rear end of the sheet is excellent.

[0008]

To achieve the above object, a representative recording apparatus according to the present invention comprises a recording apparatus for performing recording on a recording sheet by a recording means, in a position upstream of the recording means in the transport direction. A transport roller that transports the recording sheet, and a plurality of discharge rollers that transport the recording sheet downstream of the recording unit in the transport direction, and are disposed at the most downstream side in the transport direction among the plurality of discharge rollers. Further, the most downstream discharge roller has a higher accuracy than the upstream discharge roller located on the upstream side.

According to the above arrangement, of the plurality of discharge rollers for conveying the sheet downstream of the recording means in the conveyance direction, the discharge roller at the most downstream side in the sheet conveyance direction is compared with the discharge roller at the upstream side. By forming the sheet with high precision, it is possible to improve the conveyance accuracy with only the plurality of discharge rollers, and it is possible to provide a good recorded image at the rear end of the sheet. At this time, an inexpensive material and a manufacturing method can be adopted for the discharge roller on the upstream side in the transport direction among the plurality of discharge rollers, and the above-described effects can be obtained without requiring a great increase in cost.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a sheet conveying apparatus to which the present invention is applied will be described below in detail with reference to the drawings. In the following embodiments, the recording apparatus is used.
1 illustrates a transport device that transports a recording medium downstream of a recording unit in a transport direction.

[First Embodiment] A recording apparatus according to a first embodiment will be described with reference to FIGS. 1 is a perspective view of the recording apparatus with the movable cover member opened, FIG. 2 is a perspective view of the recording apparatus with the movable cover member closed, FIG. 3 is a perspective view of the inside of the apparatus, and FIG. FIG. 5 is a top view of the transport unit and the discharge unit.

Here, the configuration of the entire apparatus will be described first, and then the configuration of a discharge unit which is a sheet conveying apparatus to which the present invention is applied will be described.

As shown in FIGS. 1 and 2, the main body of the recording apparatus is covered with a main case 1 and a bottom case 2.
The cases 1 and 2 are fixed to a part of the frame of the recording apparatus to form a fixed cover member, and cover the recording medium transport unit and the recovery unit described later with this case.

An opening is formed in a part of the main case 1, and an access cover 3 is attached so as to cover the opening. This access cover 3
Is configured as a movable cover member rotatably attached to the main case 1. As shown in FIG. 1, opening the access cover 3 enables access to a carriage unit, which will be described later. Or ink tank replacement.

As shown in FIG. 3, a recording apparatus main body is built in the cover. In FIG. 3, 4
Is a chassis forming a frame of the apparatus, to which a main case 1 and a bottom case 2 are fixed.

Reference numeral 5 denotes a feeding unit on which a sheet (recording medium) P before recording is placed, and a feeding roller (not shown) is rotated by a recording start signal to feed the sheet P by one.
Separately feed each sheet. The fed sheet is conveyed through the recording area and discharged by a conveyance unit 6 including a conveyance roller and a pinch roller, and a discharge unit 7 including a plurality of discharge rollers and a rotating body having a small recording medium contact area such as a spur. You.

A carriage unit 8 as a recording means is provided in the recording area, and performs predetermined recording on the conveyed sheet P. In the present embodiment, a serial type ink jet recording system is used, and a carriage 8a is mounted so as to be reciprocally movable along a guide shaft 8b.
The recording head and the ink tank 8c are mounted on the printer.
Then, an ink image is recorded on the sheet P conveyed to the recording area by discharging ink from the recording head in synchronization with the movement of the carriage 8a. A recovery unit 9 is provided at the end of the moving area of the carriage 8a so as to face the recording head, and performs recording without causing ink ejection failure by sucking ink from the recording head before starting recording. .

The printed sheets are discharged by the discharge unit 7 and sequentially discharged and stacked on a discharge tray 10 detachably mounted on the bottom case 2 below the discharge unit 7 as shown in FIG. Is done.

Next, the configuration of a discharge unit, which is a sheet conveying device to which the present invention is applied, will be described with reference to FIGS. As described above, FIG. 4 is a sectional view of the transport unit and the discharge unit, and FIG. 5 is a top view of the transport unit and the discharge unit.

As shown in FIG. 4 and FIG.
Has a main transport roller 13 for transporting the sheet P, and a platen 12 for setting a separation distance between the sheet P and the recording head 11. The drive output from the motor 14 is transmitted to the main transport roller 13. Further, a pinch roller 18 driven by the friction driving force of the main transport roller 13 and the sheet P is in contact with the main transport roller 13. The pinch roller 18 is urged toward the main transport roller 13 by a spring member (not shown) to generate a transport force for the sheet P. Each pinch roller 18 is 500 [gf] (4.9 [N])
Is applied to the main transport roller 13.

The discharge unit 7 is provided downstream of the recording head 11 to discharge the sheet P on which image recording has been completed and to stabilize the behavior of the sheet P during image recording. The discharge unit 7 includes discharge rollers 16, 17, which are two transport rotating bodies disposed in parallel with the main transport roller 13.
Spurs 19, 20, which are a plurality of driven rotators that are driven and rotated while pressing the sheet P against the discharge rollers 16, 17, respectively.
And a transport device including a discharge tray 10 for stacking the discharged sheets P and the like.

The discharge rollers 16 and 17 are attached to the platen 12 and output gears 13 provided at one end of the main transport roller 13.
The drive is transmitted from a through transmission gears 21 and 22 to discharge roller gears 16b and 17b provided at one end of each of the discharge rollers 16 and 17.

On the other hand, the discharge tray 10
Are arranged below the second discharge roller 17 so that a plurality of sheets can be stacked.

The main transport roller 13, the first discharge roller
16, the second discharge roller 17 is substantially the same height.

Next, an image recording operation of the recording apparatus configured as described above will be described.

The sheet P separated and fed by the feeding unit 5 is nipped and conveyed by a main conveying roller 13 and a pinch roller 18. When the sheet P reaches a predetermined position where an image on the platen 12 is recorded, the carriage unit 8
Are reciprocated by a carriage motor (not shown) in a direction intersecting the sheet conveying direction, and the recording head 11 ejects ink toward the sheet P by a signal from an electric board (not shown) to record an image.

Here, the sheet P is sandwiched between the first discharge roller 16 and the first spur 19 and the second discharge roller 17 and the second spur 20 on the downstream side of the recording head 11, and the main transport roller is on the upstream side. The sheet is conveyed and recorded by being pinched by the pinch roller 13 and the pinch roller 18. Then, after recording within a predetermined range from the leading edge of the sheet P, the trailing edge of the sheet P falls out of the nip portion between the main transport roller 13 and the pinch roller 18. The subsequent conveyance is performed only by the plurality of discharge roller pairs, so that the sheet P
The recording by the recording head 11 can be performed up to the entire rear end.

Here, in the present embodiment, of the plurality of discharge rollers, the second discharge roller 17 on the most downstream side in the transport direction has a higher precision than the first discharge roller 16 on the upstream side. Is formed. Specifically, as shown in FIG. 5, as the configuration of the second discharge roller 17 on the most downstream side in the transport direction, metal (SUM22D + KN plating) is used for the shaft 17c.
Rubber (EPDM: hardness 70) is applied to the roller 17d, which is the sheet conveying section.
°). The second discharge roller 17 has a shaft 17c.
After the roller portion 17d is pressed into the roller portion 17d, the roller portion 17d is polished, so that the outer diameter accuracy of the roller portion 17d is φ15 ± 0.02 [m
m] and a runout accuracy of 0.05 [mm]. This precision can be achieved by employing a highly rigid metal shaft and polishing the roller portion.

On the other hand, as a configuration of the first discharge roller 16 upstream of the second discharge roller 17, a resin (ABS) is used for the shaft 16c, and a thermoplastic elastomer ( TPE: hardness 70 °) was used. The first discharge roller 16 is formed by integrally molding a shaft 16c and a roller portion 16d. In this case, the outer diameter accuracy of the roller portion 16d is φ15 ± 0.2 [mm], and the runout accuracy is 0.3 [mm].

As described above, the first discharge roller 16 is made of an inexpensive material and a manufacturing method, and the second discharge roller 17 employs a material giving priority to accuracy. It can provide a loose paper feed configuration.

Here, the second discharge roller 17 on the most downstream side in the transport direction is formed with higher precision than the first discharge roller 16 on the upstream side, so that the transport accuracy of the sheet P can be improved. The principle of improvement will be described.

After the rear end of the sheet P has passed through the main transport roller 13, the sheet P is transported by the two discharge rollers 16 and 17 as described above, and performs recording. The state of the sheet P at this time is shown in FIG.
As shown in the figure, the portion ahead of the second discharge roller 17 is
It hangs below the discharge roller 17, and then the discharge tray
Move along 10. In this state, a force acts on the rear end of the sheet P in a direction in which the sheet P is lifted around a tangent L between the second discharge roller 17 and the second spur 20. This is a force generated by the weight and stiffness of the sheet P. It is the role of the first spur 19 to secure the separation distance between the sheet P and the recording head 11 in opposition to this force and to keep the conveyance state of the sheet P good. The pressing force of the first spur 19 on the first discharge roller 16 decreases.

On the other hand, since the sheet P is in contact with the second discharge roller 17 so as to be wound in the circumferential direction by its own weight, the conveying force of the second discharge roller 17 to the sheet P becomes very large. As a result, the influence on the conveyance accuracy of the sheet P from the second discharge roller 17 becomes extremely large.

Due to such a phenomenon, the discharge roller at the most downstream side in the conveyance direction having a large conveyance force for the sheet P is configured with higher accuracy than the discharge roller at the upstream side. The spurs 19 and 20 are arranged to face the roller portions 16d and 17d of the discharge rollers 16 and 17, respectively, and have relatively small forces of 10 [gf] (98 [mN]) by spring members (not shown). Is set so that a pressing force is applied to the rubber member (roller portion). This is to prevent the surface of the recorded sheet P from being damaged and to maintain a good image state.

FIG. 6 shows experimental data obtained in determining this configuration.

As can be seen from the results shown in FIG. 6, it is a matter of course that the configuration in which the accuracy is improved for both the first discharge roller 16 and the second discharge roller 17 is the best result of ± 12 [μm] in 3σ. However, the second discharge roller 17 described in the present embodiment
The configuration in which only the accuracy is improved can secure the same level of accuracy as ± 15 [μm].

This is because there is a great difference when compared with ± 35 [μm] as a result of improving the accuracy of only the first discharge roller 16, and it is most efficient to increase the accuracy of only the second discharge roller 17. It is obvious at a glance.

Note that 3σ is a value obtained by multiplying the standard deviation σ by 3, and it can be expected that the non-defective rate will be 99.73% (within the numerical value of 3σ) in mass production. Therefore, it is a reference value when considering products.

As described above, according to the present embodiment, in a device having a plurality of discharge rollers for discharging a sheet, of the plurality of discharge rollers, the discharge roller on the most downstream side in the sheet conveyance direction is used. By forming the sheet with higher precision than the discharge roller on the upstream side, it is possible to improve the conveyance accuracy only by the discharge roller, and it is possible to provide a good recorded image at the rear end of the sheet. .
At this time, an inexpensive material and a manufacturing method can be adopted for the discharge roller on the upstream side, and the above-described effects can be obtained without requiring a great increase in cost.

It should be noted that the numerical values, materials, and the like described in the present embodiment are merely examples, and it is not necessary to limit the present invention to these numerical values, materials, and the like.

It is not necessary to limit the number of discharge rollers to two, and the same effect can be obtained even when a plurality of discharge rollers are used.

[Second Embodiment] In the above-described first embodiment, the pressing force of each spur 19, 20 against each roller portion 16d, 17d of the first discharge roller 16 and the second discharge roller 17 is different.
Although it is set to 10 [gf] (98 [mN]), in the present embodiment, each second spur 20 with respect to each roller portion 17d of the second discharge roller 17 is set.
By increasing only the pressing force to 20 [gf] (196 [mN]), it is possible to further improve the conveyance accuracy of the sheet P when conveyed by only the discharge rollers.

This is because each roller section 17 of the second discharge roller 17
By making the pressing force of each of the second spurs 20 on the roller portion 16d of the first discharge roller 16 larger than the pressing force of each of the first spurs 19 on the first discharge roller 16, the second discharge roller 17 with high roller accuracy can be obtained.
This is because the contribution ratio at the time of transport of the image is increased.

In this case, as shown in FIG. 7, two spurs 20 are provided on each roller portion 17d of the second discharge roller 17.
Is desirably provided. By adopting a configuration in which a force of 20 [gf] (196 [mN]) is applied to the two spurs in this manner, the pressing force from the spur 20 on each roller portion 17d of the second discharge roller 17 is: Although it is 20 [gf] (196 [mN]) which is twice as large as that of the first embodiment, the pressing force per spur 20 is 10 [gf] (98 [mN]). Without sheet P
Since the pressing force against is only 10 [gf] (98 [mN]),
A great force is not applied to the recorded sheet P, the surface of the sheet P is prevented from being damaged, and a good recording result can be obtained.

As described above, according to the present embodiment, the pressing force of the second spur 20 on the second discharge roller 17 on the most downstream side in the sheet conveying direction is increased by the first discharge roller 16 on the upstream side. Is greater than the pressing force of the first spur 19 with respect to the sheet, it is possible to further improve the conveyance accuracy using only the discharge roller, and it is possible to provide a good recorded image at the rear end of the sheet. Become.

It should be noted that the numerical values, materials, and the like described in the present embodiment are merely examples, and it is not necessary to limit the present invention to these numerical values, materials, and the like.

[Third Embodiment] A third embodiment will be described with reference to FIGS. In the third embodiment, the load torque is applied to the second discharge roller by a leaf spring and a friction pad constituting the load torque applying means. FIG. 8 is a top view of a transport unit and a discharge unit according to the third embodiment, and FIG. 9 is a sectional view of a second discharge roller.

In FIG. 9, the friction pad 24 is pressed against the shaft 17c of the second discharge roller 17 by a leaf spring 23. In the present embodiment, artificial leather is used for the friction pad 24, and SUS304 having a plate pressure of 0.3 [mm] is used for the leaf spring 23. The load torque applied to the shaft 17c is 0.29
It is set in the range of 4 [N · cm] to 1.47 [N · cm] (30 [gf · cm] to 150 [gf · cm]).

As described above, the backlash of the roller gear 17b is removed by applying the load torque to the shaft 17c. Therefore, the gear driving is performed accurately without the roller gear 17b moving forward by the amount of the backlash, and the conveyance accuracy of the sheet P is further improved.

[Fourth Embodiment] A fourth embodiment will be described with reference to FIGS. In the fourth embodiment, a configuration is adopted in which a load torque is applied to the second discharge roller by a clutch spring that is a load torque application unit. FIG. 10 is a top view of a second discharge roller according to the fourth embodiment, and FIG. 11 is a sectional view of the second discharge roller.

In FIG. 11, ribs 26a and 26b are provided near both ends of the clutch spring 25. For this reason, even if the shaft 17c of the second discharge roller rotates forward or backward, a force acts in a direction in which the clutch spring 25 is loosened.
Twenty-five loose torques are applied to the shaft 17c. In this embodiment, the clutch spring 25 is made of SUS3 having a wire diameter of 0.45 [mm].
03 is used. The load torque applied to the shaft 17c has substantially the same value as in the third embodiment.

In this embodiment, as in the third embodiment, the backlash of the roller gear 17b is removed by applying a load torque to the shaft 17c. Therefore, the gear driving is performed accurately without the roller gear 17b moving forward by the amount of the backlash, and the conveyance accuracy of the sheet P is further improved.

[Fifth Embodiment] A fifth embodiment will be described with reference to FIG. In the fifth embodiment, a configuration is adopted in which a load torque is applied to the second discharge roller by a compression coil spring that is a load torque applying unit. FIG. 12 is a top view of the second discharge roller according to the fifth embodiment.

In FIG. 12, the compression coil spring 27 is inserted between the platen 12 supporting the shaft 17c of the second discharge roller and the roller gear 17b, so that the roller gear 17b
To generate a load torque. In this embodiment, the compression coil spring 27 is made of SUS having a wire diameter of φ0.7 [mm].
I'm using 303. The load torque applied to the shaft 17c has substantially the same value as in the third embodiment.

In this embodiment, as in the third embodiment, the backlash of the roller gear 17b is removed by applying a load torque to the shaft 17c. Therefore, the gear driving is performed accurately without the roller gear 17b moving forward by the amount of the backlash, and the conveyance accuracy of the sheet P is further improved.

[Sixth Embodiment] In the above-described embodiment, the first discharge roller 16 and the second discharge roller 17 have a roller portion 16d, 17d made of an elastomer having a hardness of 70 ° and a rubber member of EPDM. However, in the present embodiment, the sheet P of the roller portion 17d of the second discharge roller 17 on the most downstream side in the sheet conveying direction is
Is made higher than the friction coefficient μ of the roller portion 16d of the first discharge roller 16 on the upstream side with respect to the sheet P, it is possible to further improve the conveyance accuracy.

In this embodiment, the second discharge roller
EPDM hardness 50 °, first discharge roller 16
The hardness of the elastomer was 90 ° for the roller portion 16d. The coefficient of friction μ for both sheets P is 1.2 for the former and 0.8 for the latter.
When the same pressing force is applied, a higher conveying force can be applied to the sheet P when the hardness is 50 °. Therefore, the contribution ratio of the second discharge roller 17 having good roller accuracy to the conveyance of the sheet P is further increased, and the conveyance accuracy is further improved.

As described above, according to the present embodiment, the coefficient of friction of the second discharge roller 17 on the most downstream side in the sheet conveying direction with respect to the sheet P is determined by the sheet of the first discharge roller 16 on the upstream side. By setting the coefficient of friction higher than the friction coefficient with respect to P, it is possible to further improve the conveyance accuracy using only the discharge roller, and to provide a good recorded image at the rear end of the sheet.

It should be noted that the numerical values, materials, and the like described in the present embodiment are given as examples, and it is not necessary to limit to these numerical values, materials, and the like.

[Seventh Embodiment] In the above embodiment, the type and number of recording heads were not specifically illustrated and described. However, the present invention relates to an ink jet recording apparatus using one recording head, Recording such as an ink jet recording apparatus for color recording using a plurality of recording heads for recording with inks of different colors, or an ink jet recording apparatus for gradation recording using a plurality of recording heads for recording with inks of the same color and different densities. It can be applied irrespective of the type and number of heads, and can achieve the above-described effects.

Further, as a recording means (recording head), a cartridge type in which a recording head and an ink tank are integrated, a recording head and an ink tank which are separated and connected to each other by an ink supply tube, and the like can be used. Regardless of the configuration of the recording means and the ink tank, the same can be applied and the same effect can be achieved.

When the present invention is applied to an ink jet recording apparatus, the present invention can be applied to, for example, an apparatus using recording means using an electromechanical transducer such as a piezo element.
In particular, the present invention brings about an excellent effect in an ink jet recording apparatus using a recording means of a method of discharging ink using thermal energy. According to such a method, it is possible to achieve higher density and higher definition of recording.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by combining a plurality of recording heads, or a configuration as a single recording head that is integrally formed. in addition,
Even with the serial type described above, a print head fixed to the apparatus main body, or a replaceable chip that can be electrically connected to the apparatus main body and supplied with ink from the apparatus main body when attached to the apparatus main body The present invention is also effective when a recording head of a type or a cartridge type recording head in which an ink tank is provided integrally with the recording head itself is used.

The form of the above-described ink jet recording apparatus is not only used as an image output terminal of an information processing apparatus such as a computer, but also an ink jet input / output apparatus capable of mounting a scanner other than a recording head on a carriage. It may be a copying machine combined with an apparatus, a reader, or the like, or a facsimile apparatus having a transmission / reception function.

In the above-described embodiment, the ink jet recording method is exemplified as the recording method. However, the recording method is not limited to the ink jet recording method.
Furthermore, an impact recording method such as a wire dot recording method or a recording method such as another electrophotographic method can be applied.

[0066]

As described above, according to the present invention,
In a recording apparatus having a plurality of discharge rollers for conveying a sheet on a downstream side in a conveyance direction from a recording unit, among the plurality of discharge rollers, a discharge roller on a most downstream side in a sheet conveyance direction is a discharge roller on an upstream side thereof. As a result, it is possible to improve the conveyance accuracy using only the plurality of discharge rollers, and to provide a good recorded image at the rear end of the sheet. At this time, an inexpensive material and a manufacturing method can be adopted for the transporting means on the upstream side in the transport direction among the plurality of discharge rollers, and the above-described effects can be obtained without a great increase in cost.

[Brief description of the drawings]

FIG. 1 is a perspective view of a recording apparatus with a movable cover member opened.

FIG. 2 is a perspective view of the recording apparatus with a movable cover member closed.

FIG. 3 is a perspective view of the inside of the apparatus.

FIG. 4 is a sectional view of a transport unit and a discharge unit according to the first embodiment.

FIG. 5 is a top view of the transport unit and the discharge unit according to the first embodiment.

FIG. 6 shows experimental data of the conveyance accuracy of the sheet P when the accuracy of the discharge roller is changed.

FIG. 7 is a top view of a transport unit and a discharge unit according to a second embodiment.

FIG. 8 is a top view of a transport unit and a discharge unit according to a third embodiment.

FIG. 9 is a sectional view of a second discharge roller according to the third embodiment.

FIG. 10 is a top view of a second discharge roller according to a fourth embodiment.

FIG. 11 is a sectional view of a second discharge roller according to a fourth embodiment.

FIG. 12 is a top view of a second discharge roller according to the fifth embodiment.

FIG. 13 is a sectional view of a conventional transport unit and discharge unit.

[Explanation of symbols]

 L ... tangential line P ... sheet 1 ... main case 2 ... bottom case 3 ... access cover 4 ... chassis 5 ... feed unit 6 ... transport unit 7 ... discharge unit 8 ... carriage unit 8a ... carriage 8b ... guide shaft 8c ... ink tank 9 ... Recovery unit 10 ... Discharge tray 11 ... Recording head 12 ... Platen 13 ... Main transport roller 13a ... Output gear 14 ... Motor 16 ... First discharge roller 16b ... Discharge roller gear 16c ... Shaft 16d ... Roller part 17 ... Second discharge roller 17b ... Discharge roller gear 17c ... Shaft 17d ... Roller part 18 ... Pinch roller 19 ... First spur 20 ... Second spur 21,22 ... Transmission gear 23 ... Leaf spring 24 ... Friction pad 25 ... Clutch spring 26a, 26b ... Rib 27 ... Compression Coil spring

Claims (11)

[Claims] 1. A recording apparatus that performs recording on a recording sheet by a recording unit, comprising: a conveyance roller that conveys the recording sheet upstream of the recording unit in the conveyance direction; and a recording roller downstream of the recording unit in the conveyance direction. A plurality of discharge rollers to be conveyed, wherein the most downstream discharge roller disposed on the most downstream side in the conveying direction among the plurality of discharge rollers is higher in accuracy than the upstream discharge roller upstream therefrom. A recording device characterized by the above-mentioned. 2. The discharge roller according to claim 1, wherein each of the plurality of discharge rollers includes a shaft serving as a center of rotation, and a roller portion of a rubber member that conveys a recording sheet by rotating integrally with the shaft. The recording apparatus according to claim 1, wherein the shaft is made of metal, and the shaft of the upstream discharge roller is made of resin. 3. The recording apparatus according to claim 2, wherein the roller portion of the most downstream discharge roller is formed by polishing. And a driven roller that rotates in accordance with each of the plurality of discharge rollers, and applies a pressing force of a most downstream driven roller that rotates in accordance with the most downstream discharge roller to the upstream discharge roller. The recording apparatus according to any one of claims 1 to 3, wherein the pressing force is set to be greater than the pressing force of an upstream driven roller that is driven and rotated. 5. The recording apparatus according to claim 1, further comprising a load torque applying unit that applies a load torque to the most downstream discharge roller. 6. The recording apparatus according to claim 5, wherein the load torque applying means is a leaf spring and a friction pad that press against a shaft of the most downstream discharge roller. 7. The recording apparatus according to claim 5, wherein the load torque applying means is a clutch spring wound around a shaft of the most downstream discharge roller. 8. The recording apparatus according to claim 5, wherein the load torque applying means is a compression coil spring that presses a gear on a shaft of the most downstream discharge roller. 9. The apparatus according to claim 1, wherein a coefficient of friction of the lowermost discharge roller with respect to the recording sheet is higher than a coefficient of friction of the upstream discharge roller with respect to the recording sheet. The recording device according to claim 1. 10. The recording apparatus according to claim 1, wherein the recording unit is a recording head that performs recording on a recording sheet by discharging ink. 11. The recording head according to claim 10, wherein the recording head supplies electricity to the electrothermal transducer in response to a signal, and discharges ink using thermal energy generated by the electrothermal transducer. Recording device.