JPH11278712A - Recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce variations in transfer amount for a recording portion of a recording medium which occur in a portion of a pair of carrying rollers to thereby eliminate a position variation error during recording on the recording medium, even if the recording medium supplied to a recording device is cardboard such as a postcard or an envelope, in the recording device in which the recording medium sent from a paper supply section by supplying means is carried while being sandwiched between the pair of transfer rollers of a paper carrying section to a recording section where recording on the recording medium is performed. SOLUTION: After executing a recording medium carrying correcting mode in which an operation of sandwiching a recording medium P sent from a paper supply section by supplying between a pair of transfer rollers 16, 17 rotating in a normal direction, and a following operation for releasing the sandwiching by rotating the pair of transfer rollers 16, 17 in a direction opposite to the normal direction so that the recording medium thus sandwiched is moved back and left from the pair of transfer rollers 16, 17 are repeated for plural times, finally the recording medium is conveyed to a recording section while sandwiched between the pair of transfer rollers 16, 17 rotating in the normal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus for recording a recording medium fed from a paper feeding section by a feeding means between a pair of conveying rollers of the paper feeding section and conveying the recording medium to the recording section for recording on the recording medium. (Image forming apparatus).

[0002]

2. Description of the Related Art A recording apparatus as described above is widely used as a printer which is a terminal output device in, for example, a computer, a word processor, an image scanner, and a facsimile.

The paper feed unit is an automatic paper feed unit that separates and feeds a stacked recording medium, or a manual paper feed unit.

[0004] The feeding means is, for example, a pickup roller (feed roller) that is driven to rotate.

[0005] Recording media include, for example, printing paper, transfer paper,
Photosensitive paper, electrostatic recording paper, thermal paper, 2nd original drawing paper, postcards, envelopes, cards, OHP films (transparency films for overhead projectors), etc. The material is not limited to paper quality.

The transport roller pair includes, for example, a transport roller that is driven to rotate, and an auxiliary roller (pinch roller) that is urged against the transport roller by elastic means.

The recording section is a recording head mechanism of an ink jet type, an impact type, a light emitting element array type, a heating element array type, etc., and an appropriate image forming means mechanism such as an electrophotographic mechanism.

In FIG. 8A, reference numerals 16 and 17 denote a conveying roller and a pinch roller as a pair of conveying rollers in a paper feeding section of the recording apparatus. The rotation of the transport roller 16 is controlled by a drive system (not shown). The pinch roller 17 is disposed below the transport roller 16 and is elastically pressed against the lower surface of the transport roller 16 by an elastic member (not shown) to form a nip portion n. It follows and rotates.

The leading end of the recording medium P sent out by a pickup roller as a feeding means from a paper feeding unit (not shown) has a pressure contact nip portion n between a conveying roller 16 and a pinch roller 17 as a pair of conveying rollers in the paper feeding unit. Leads to. Then, the conveying roller 16 is pinched between the conveying roller 16 and the pinch roller 17 and the conveying roller 1
By the rotation of No. 6, it is conveyed to a recording unit (not shown).

At this time, the conveying roller pairs 16 and 17 are kept in a rotation stopped state or in a reverse rotation driving state in a direction opposite to the recording medium conveying direction, and the leading end of the recording medium sent out by the pickup roller of the sheet feeding unit is moved. It is also possible to perform a so-called registration (registering) removing operation for removing the skew of the recording medium by abutting the nip portion of the pair of transport rollers 16 and 17.

Depending on the recording medium, a slip with the pickup roller occurs, and if this registration operation is performed only by the rotation amount of the pickup roller from the start of sheet feeding, the recording medium does not reach the transport roller pair 16/17. In some cases, the skew is not removed, or the recording medium is wrinkled due to excessive pushing.

In such a case, it is effective to rotate the pickup roller at a predetermined number of revolutions after detection by a paper sensor provided between the paper feeding section and the paper feeding section.

[0013]

Here, the nipping of the recording medium P between the conveying roller 16 and the pinch roller 17, which is a pair of conveying rollers, depends on the feeding force of the recording medium by the pickup roller of the sheet feeding unit or the conveying roller. Conveyance roller 1 at the leading end of the recording medium due to the deflection reaction of recording medium P between pinch roller pairs 16 and 17 and the pickup roller
This is performed by causing the leading end portion of the recording medium to bite between the transport roller 16 and the pinch roller 17 by the abutting force between the roller 6 and the pinch roller 17.

However, if the recording medium to be passed through the recording apparatus is thick paper such as a postcard and there is a burr at the end of the paper, the thickness of the burr increases. In the case of a recording medium having a folded portion such as an envelope, the leading end of the folded portion is wavy and does not form a uniform horizontal state, or the folded portion is swollen. There is a case where the biting property becomes unstable.

[0015] FIG. 8A shows a case where the recording medium P is a cardboard such as a postcard. Generally, paper is cut into a predetermined size and shape. At this time, as shown in the drawing, burrs are generated at the cut portion, and the paper thickness may be substantially larger at the paper end than at the other end of the paper. If the recording medium used for passing the paper is thick paper such as a postcard and there is a burr a at the end of the paper, the thickness of the burr increases.

At this time, when the transport roller 16 is rotated to transport the recording medium P to the recording section, a sufficient biting state is obtained between the transport roller 16 and the pinch roller 17 at the leading end of the recording medium P. Roller 16 by
And slipping occurs between the leading ends of the recording medium P.

Therefore, the transport roller 16 and the pinch roller 1
Since the biting of the recording medium P between the gaps 7 was not constant due to a substantial variation in the paper thickness, a large variation occurred between the rotation amount of the transport roller 16 and the transport amount of the recording medium P.

If there is little variation in the transport amount of the recording medium due to slippage between the transport roller 16 and the leading end of the recording medium P when the recording medium P bites between the transport roller 16 and the pinch roller 17, the rotation amount of the transport roller 16 is small. Although the recording medium can be moved to the regular recording position of the recording unit by adjusting the above, there is a problem that if the variation is large, a recording position deviation error occurs on the recording medium.

[0019] FIG. 9A shows a case where the recording medium P is a recording medium including a folded portion b such as an envelope. At the end of the paper having the folded portion b like an envelope, the substantial variation in the paper thickness is very large due to the amount of collapse of the folded portion b.

Further, since the undulation c is generated at the end of the paper, the recording medium P does not bite uniformly between the transport roller 16 and the pinch roller 17 or only a partial bite is obtained. Therefore, as in the case described above, a large variation occurs between the rotation amount of the conveyance roller 16 and the conveyance amount of the recording medium P. If the variation is large, there has been a problem that a recording position deviation error on a recording medium occurs.

Accordingly, the present invention relates to a recording apparatus for recording a recording medium fed from a paper feeding section by a feeding means between a pair of conveying rollers of the paper feeding section and conveying the recording medium to the recording section for recording on the recording medium. Even if the recording medium to be used for paper passing is a thick paper such as a postcard or an envelope, it is possible to reduce the variation in the transport amount of the recording medium to the recording unit caused by the above-described factors in the pair of transport rollers of the paper transport unit. An object of the present invention is to eliminate a recording position deviation error on a recording medium.

[0022]

According to the present invention, there is provided a recording apparatus having the following configuration.

(1) In a recording apparatus, a recording medium sent from a paper supply unit by a feeding means is sandwiched between a pair of conveyance rollers of a paper supply unit, conveyed to a recording unit, and recorded on the recording medium.
A recording medium nipping operation for nipping a recording medium sent out from a paper feeding unit by a feeding means between a pair of normally rotating conveyance rollers, and, after this recording medium nipping operation, rotating the conveyance roller pair in a reverse direction to sandwich the recording medium. The recording medium conveyance correction mode is executed in which the recording medium is released from the pair of conveyance rollers to release the nip by retreating the recording medium, and the nip release operation is repeatedly performed a plurality of times. A recording apparatus wherein a recording medium is sandwiched between the recording medium and the recording medium is conveyed to a recording unit.

(2) The recording apparatus according to (1), wherein the paper supply unit is an automatic paper supply unit that separates and feeds the stacked recording media, or a manual paper supply unit.

(3) The recording apparatus according to (1) or (2), further including release means for releasing the feeding means and the recording medium.

(4) The recording apparatus according to any one of (1) to (3), wherein the feeding means is a paper feed roller of a missing circle type.

(5) The transport roller pair of the paper feeding section is characterized by a transport roller driven forward and backward and a supplementary roller urged against the transport roller by elastic means (1). The recording device according to any one of (1) to (4).

(6) The conveying roller has a diameter of about 10 m.
m. The recording apparatus according to (5), wherein m is equal to or less than m.

(7) In the operation of nipping the recording medium between the pair of conveying rollers, a feeding force is applied to the recording medium by the feeding means, which is one of (1) to (6). The recording device according to any one of the preceding claims.

(8) The recording medium nipping releasing operation for releasing the nipping of the recording medium by rotating the pair of conveying rollers in reverse to retract the nipped recording medium to return from the pair of conveying rollers and release the nipping is performed by the feeding means, the recording medium, The recording apparatus according to any one of (1) to (7), wherein the recording is performed in a state in which is released.

(9) The recording medium transport correction mode is executed only when transporting thick paper in which the recording medium passed through the apparatus is thick paper. (1) Any one of (1) to (8) The recording device according to claim 1.

<Operation> That is, even if the recording medium P sent out from the sheet feeding unit by the feeding means has a burr at the end of the sheet, the recording medium is conveyed by the above-described recording medium conveyance correction mode. By performing a plurality of repetitions of the pinching operation and the pinching releasing operation on the transport roller pair by the forward / reverse control of the pair, the burrs a are crushed as shown in FIG. The variation in the paper thickness at the time is small. Therefore, the biting of the recording medium P between the pair of conveying rollers 16 and 17 is stabilized between the recording media, and the recording medium finally conveyed to the recording unit by being sandwiched between the pair of conveying rollers 16 and 17 that has been rotated forward. The variation in the biting property of the recording medium between the pair of transport rollers caused by the variation in the paper thickness between them can be reduced, and the transport with less variation in the transport amount than the conventional apparatus (the recording apparatus without the recording medium transport correction mode). Becomes possible.

Also, in the case of a recording medium having a folded portion or a wavy portion such as an envelope, the recording medium is similarly held in the conveyance roller pair by the forward / reverse control of the conveyance roller pair in the recording medium conveyance correction mode. By performing a plurality of repetitions of the operation and the holding release operation, the bulging portion of the folded portion b is crushed as shown in FIG. Variations are also reduced. In addition, the corrugated shape is corrected, and the recording medium is partially prevented from biting between the conveying roller pairs 16 and 17.
And the amount of slip between the recording medium and the recording medium decreases. Therefore, the biting of the recording medium between the conveying roller pairs 16 and 17 is stabilized between the recording media, and finally the conveying roller pair 16
17 can reduce the variation in the biting property of the recording medium between the pair of transport rollers caused by the variation in the paper thickness between the recording media conveyed to the recording unit while being pinched between the recording media 17 and the variation in the transport amount as compared with the conventional apparatus. Can be conveyed.

Thus, even when the recording medium to be passed through the apparatus is thick paper such as a postcard or an envelope, the amount of slip between the transport roller and the recording medium is stabilized between the recording media, and the transport of the paper at the paper feeding section is performed. Variations in the conveyance amount of the recording medium with respect to the recording section, which occur at the roller pair, can be reduced to eliminate a recording position deviation error on the recording medium.

[0035]

FIG. 1 is an external perspective view of an example of a recording apparatus according to the present invention, FIG. 2 is a schematic configuration diagram of an internal mechanism, and FIG. 3 is a block diagram of a control system.

(1) External Configuration of Apparatus In FIG. 1, reference numeral 1 denotes an outer casing of the main body of the apparatus, and 2 denotes a hinge portion (rotating shaft) on the rear side with respect to the upper surface of the outer casing of the main body of the apparatus.
It is a cover that can be opened and closed around the center, and also serves as a paper tray. FIG. 1 shows a state in which the cover 2 is opened and raised from the upper surface of the recording apparatus main body 1. When the apparatus is not used, the cover 2 is closed by falling down on the upper surface of the apparatus main body outer casing 1.

On the upper surface of the outer casing 1 of the apparatus main body, key tops 4 for operating the recording apparatus, a display section 5 such as a liquid crystal type, a recording head exchange lid section 6, a paper feed port 7 and the like are arranged. It is.

The key tops 4 are tact switches for performing operations such as power ON / OFF and paper feeding / discharging.

The display section 5 displays information such as the operation status of the recording medium, the setting status, and the error mode.

The recording head replacement cover 6 is provided at a position corresponding to a part of the moving range of the recording head carriage inside the apparatus main body, and is freely openable and closable about a hinge (not shown). Thus, the recording head carriage inside the apparatus main body is opened, and the recording head can be replaced.

The paper feed port 7 is a horizontally long opening formed on the rear side of the upper surface of the outer casing of the apparatus main body along the rear side. The recording medium is a paper tray with a cover opened from the upper surface of the recording apparatus main body 1 as a paper tray. Set.

Reference numeral 8 denotes a paper guide (side guide) provided in the paper feed port 7, which has a certain friction and is slidable left and right along the length of the paper feed port 7, By sliding the recording medium in accordance with the width of the recording medium set on the paper tray 2, the side position of the recording medium is regulated, thereby serving to maintain the stacking alignment of the recording medium.

Reference numeral 9 denotes a horizontally long discharge port opened at the front of the recording apparatus main body 1.

The control unit of the recording device is electrically connected to a host device (not shown) such as a computer, a word processor, an image scanner, and a facsimile.

(2) Internal Configuration of the Apparatus <Sheet Feeding Unit> In FIGS. 2 and 3, reference numeral 11 denotes a pickup roller (sheet feeding roller) as a feeding means. The pickup roller 11 of the present example is a fan-shaped (partially circular type) in which a part of an arc is cut out.

Reference numeral 12 denotes a pressure plate disposed below the pickup roller 11 in a downwardly inclined position. The pressure plate 12 can freely swing up and down around a hinge portion 13 on the rear side, and is always urged upwardly around the hinge portion 13 by a pressure plate spring (not shown). When the sheet is on standby, the pressure plate 12
Is pushed down to a predetermined standby position against a pressure plate spring by a cam mechanism (not shown) and is held at that position. FIG.
Indicates this state.

A separation pad 14 having a controlled friction coefficient is mounted on the upper surface of the pressure plate 12. With reference to the friction coefficient between the separation pad 14 and the recording medium P, the friction coefficient between the recording media is set lower than the friction coefficient between the separation pad 14 and the recording medium and larger than the friction coefficient between the pickup roller 11 and the recording medium P. .

Reference numeral 15 denotes a movable bank composed of a sheet-like elastic body disposed in front of the pressure plate 12 on the front end side.

The pickup roller 11 is driven to rotate by a pickup motor M1 (FIG. 3). The pickup roller 11 is held in a rotation-stopped state at a rotation angle posture in which the missing circle portion faces the pressure plate 12 at the time of paper feed standby, and the pickup roller 11 and the pressure plate 12 are largely separated from each other. .

The leading end of the recording medium S is inserted into the apparatus main body through the paper feed port 7 and the leading end is
It is placed and set on the pressure plate 12 and the paper tray 2 in a state where it is sufficiently inserted until it comes into contact with the movable bank 15 through the gap between the pressure plate 12 and the movable bank 15 and is received. The recording medium P to be set may be a single sheet, or a plurality of sheets may be stacked. Since the pickup roller 11 and the pressure plate 12 are largely separated from each other, the recording medium P can be easily set.

A sheet feeding section (automatic sheet feeding mechanism: ASF) is constituted by the above members 11 to 15 and the like. The set recording medium P is separated one by one from the sheet feeding section in order from the uppermost one. Paper is fed. This single sheet feeding operation will be described later.

<Sheet Feeding Unit> Reference numerals 16 and 17 denote a pair of conveying rollers for nipping and conveying the recording medium sent from the sheet feeding unit to the recording unit. The upper roller 16 is a transport roller, and the lower roller 17 is a pinch roller as an auxiliary roller.

The pinch roller 17 is rotatably supported by a lever member 19 which can swing up and down about a shaft 18. The lever member 19 is urged up by a push-up spring 20 about the shaft 18. As a result, the pinch roller 17 is elastically pressed against the lower surface of the transport roller 16 to form a nip n.

The transport roller 16 is driven to rotate forward and backward by a transport motor M2. The pinch roller 17 is the transport roller 1
The motor rotates forward / reverse by following the forward / reverse drive of No.6.

The recording medium is nipped between the transport roller 16 and the pinch roller 17 and transported by friction with the rotating transport roller 16. For this reason, the transport roller 16 has an outer peripheral surface made of a material having relatively high friction such as rubber. In addition, as a means for realizing a high friction surface property, there is also a method by a coating film of urethane or the like, or a blast treatment for forming irregularities of several microns on the metal surface.

Reference numeral 21 denotes a paper sensor lever disposed on a paper path (recording medium passage) between the paper feed unit and the pair of conveying rollers 16 and 17, which is swingable about a shaft 22.
When the recording medium P is sent out from the paper feeding unit, the leading end of the sent recording medium P contacts the lower end of the paper sensor lever 21 and pushes the same to rotate the lever 21. The paper sensor 23 responds to the rotation of the lever 21 to detect the leading end of the recording medium P sent from the paper feeding unit. Further, when the rear end of the recording medium P passes through the lower end of the paper sensor lever 21, the lever 21 returns and rotates. The paper sensor 23 responds to this and the rear end of the recording medium P is detected.

The paper sensor 23 including the paper sensor lever 21 is attached to the panel board 24. The panel board 24 includes a paper feed unit and a pair of transport rollers 16.1
7 is provided in parallel with the largest surface of the surfaces constituting the recording apparatus main body and near the operation surface. Specifically, the panel board 24 is disposed directly below the position of the key tops 4 (FIG. 1) on the upper surface of the outer casing 1 of the apparatus main body, and the force applied to the key tops 4 is detected by a detector (not shown). It is converted into an electric signal on the panel board 24.

25/26, 27/28 are transport roller pairs 1
6 and 17 are provided on the downstream side in the recording medium conveyance direction.
And a second discharge roller pair. The lower rollers 25 and 27 are discharge rollers, and the upper rollers 26 and 2
Reference numeral 8 denotes a pinch roller (spur) brought into contact with the upper surfaces of the paper discharge rollers 25 and 27. The discharge roller 25 is a discharge motor M3.
Is driven to rotate. The discharge roller 27 rotates in conjunction with the rotation of the discharge roller 25.

The recording medium P sent out from the paper feeding section receives a pair of transport rollers 16 and 17, a first pair of discharge rollers 25 and 26,
The paper is conveyed along the path of the second pair of paper discharge rollers 27 and 28, and is discharged out of the apparatus from a horizontally long discharge port 9 (FIG. 1) opened on the front surface of the recording apparatus main body 1.

The control of the apparatus including the forward / reverse control of the conveying roller pairs 16 and 17 during the execution of the recording medium correction mode, which is the main point of the present invention, will be described later.

<Recording unit> 29 is a recording head, for example, an ink jet recording head. Reference numeral 30 denotes a carriage on which the recording head 29 is mounted. The carriage 30 is arranged above the transport roller pairs 16 and 17 and the first and second paper discharge roller pairs 25, 26, 27 and 28 along the left-right guide shaft 31 and the guide rail 32 parallel to each other. It is freely slidably movable in the left and right directions inside.

The carriage 30 has a box-like shape with an open top, and the inner wall of the box is provided with electrical signal contacts, a recording head fixing member, positioning means, and the like.
The recording head 29 is fitted in the box shape in a predetermined manner and mounted on the carriage 30. As described above, the operation of attaching and detaching and replacing the recording head 29 with respect to the carriage 30 is performed by opening the recording head replacement cover 6 (FIG. 1) provided on the upper surface of the apparatus main body outer casing 1 and opening the upper side of the carriage 30. Done.

In a state where the recording head 29 is mounted on the carriage 30 in a predetermined manner, the downward recording portion surface 29a of the recording head 29 is in contact with the transport roller pairs 16 and 17 and the first roller.
Platen 3 between the pair of paper ejection rollers 25 and 26
2 with a predetermined gap.

The carriage 30 is slidably controlled in the horizontal direction in the recording apparatus along a guide shaft 31 and a guide rail 32 by a carriage motor M4 and a carriage belt (not shown) according to a recording signal. Reference numeral 33 denotes a sensor unit for positioning the carriage 30, and the sensor unit 33 is attached to a carrier traveling portion of the apparatus chassis. The sensor unit 33 is a transmission type photo interrupter, and detects the passage of the light shielding plate 30a on the carriage 30 side and detects the passage of the carriage 30.
The position in the left-right direction along the guide shaft 31 and the guide rail 32 is detected.

The carriage 30 is electrically connected to the control board 34 via a carrier flexible (not shown).
Numeral 9 communicates with the carrier flexure via an electrical signal contact provided on the carriage 30 and is controlled by the control board 34.

In the platen section 32 between the pair of transport rollers 16 and 17 and the pair of first discharge rollers 25 and 26, the recording medium is controlled by controlling the movement of the recording head carriage 30 and the recording head 29. A print record is made on the surface.

(3) Recording Medium Transport Correction Mode FIGS. 4 and 5 are explanatory diagrams of the operation process of the apparatus when the recording medium transport correction mode is executed, and FIGS. 6 and 7 are flowcharts of a control sequence performed by the control unit.

Here, symbols used in the flowcharts of FIGS. 6 and 7 will be described.

N: Number of times the recording medium has been pinched between the pair of transport rollers 16 and 17 N1: Number of times the recording medium has been pinched between the pair of transport rollers 16 and 17 (set number of times) X1 : Forward rotation amount of pickup roller (rotation amount for moving recording medium from pickup roller 11 to conveyance roller pair 16/17) X2: Forward rotation amount of pickup roller (pressing recording medium against pressure nip n of conveyance roller pair 16/17) Amount = registration removal amount) X3: Pickup roller forward rotation amount (pressing amount for holding the recording medium between the transport roller pairs 16 and 17) Y1; Transport roller forward rotation amount (Recording medium transport roller pair 16)
· Amount to be pinched between 17) Y2: Forward rotation amount of transport roller (recording medium is transferred to transport roller pair 16)
The amount by which the recording medium is conveyed to the printing area after being sandwiched between 17, but need not be conveyed to the printing section. Y3: Conveyor roller reverse rotation amount (recording medium conveying roller pair 16)
Amount to release the sandwiched state between 17; therefore, the condition is Y3> Y1 + Y2) Y4: Forward rotation amount of the transport roller (amount for transporting the recording medium to the printing area) 1) The recording medium P used to feed the recording apparatus Is selected by the user, the printing apparatus instructs the number of times the printing medium has been pinched between the pair of transport rollers 16 and 17 (N = N1, step S1).

At this time, the number of times of pinching is set for each type of recording medium P (normal recording paper, postcard, envelope, etc.).

2) Paper tray 2 and pressure plate 12 in paper feed section
The recording medium P is placed and set in a predetermined manner (FIG. 4A).

The procedures 1) and 2) may be reversed.

3) Next, at the time when the recording command is issued from the CPU (FIG. 3) of the control unit, in this example, the transport roller pair 16.
The 17 transport rollers 16 are driven in the reverse rotation driving state (step S2). The transport roller 16 may be kept stopped without being driven in reverse rotation.

4) The pressure plate 12 is raised, and the pickup roller 11 is rotated forward (rotation in the sheet feeding direction) (step S3).

As a result, the set recording medium P on the pressure plate 12 comes into contact with the rotating pickup roller 11 and the pressure plate 1
A propulsive force (feeding force) is applied to the uppermost recording medium of the upper set recording medium P, and the tip of the uppermost recording medium pushes the movable bank 15 made of a sheet-like elastic body to resist elasticity. As a result, the leading end of the uppermost recording medium gets over the movable bank 15 and only the uppermost recording medium is fed and separated from the next lower recording medium (see FIG. 1). FIG. 4 (b)).

5) The leading end of the recording medium fed one by one is detected by the paper sensor lever 21 and the sensor 23 on the way to the pair of conveying rollers 16 and 17 while being fed. Then, the normal rotation amount X1 of the pickup roller 11
As a result, the leading end of the recording medium reaches the nip portion n of the pair of transport rollers 16 and 17 (FIG. 4C, steps S4 and S).
5).

6) With the further forward rotation amount X2 of the pickup roller 11, the leading end of the recording medium is pressed (butted) against the nip portion n of the transport roller pair 16, 17 in the reverse rotation state (or in the rotation stop state). After, pickup roller 1
By temporarily stopping the rotation of No. 1, the registration operation for removing the skew of the recording medium is performed (steps S6 and S6).
7).

In this case, since the transport roller pairs 16 and 17 are in the reverse rotation driving (or stopped) state,
The recording medium is not sandwiched between the recording rollers 17 and the skew of the recording medium is removed by pressing the leading end of the recording medium against the nip portion n of the pair of transport rollers 16 and 17.

7) The pickup roller 11 is rotated forward and, at the same time, the transport roller 16 is rotated forward.

The leading end of the recording medium is held between the pair of transport rollers 16 and 17 by the forward rotation amount X3 of the pickup roller 11 and the forward rotation amount Y1 of the transport roller 16 (step S).
8).

8) The recording medium is separated from the pickup roller 11 by lowering the pressure plate 12.

Thereafter, the pickup roller 11 is further rotated to return to the rotation angle state at the time of the first sheet supply standby, and the rotation is stopped. That is, the rotation is stopped at the rotation angle posture in which the missing circle portion faces the pressure plate 12. As a result, the pickup roller 11 and the pressure plate 12 are largely separated from each other, and the pickup roller 11 and the recording medium are released.

In this state, by rotating the transport roller 16 by the normal rotation amount Y2, the recording medium sandwiched between the transport roller pairs 16 and 17 is once transported in the printing area direction (FIG. 5A,
Steps S9 to S12).

9) The transport roller 16 is driven to rotate in the reverse direction (step S13). The reverse rotation amount Y of the transport roller 16 at this time
3 is the forward rotation amount (Y1 + Y
Make the value larger than 2).

By the reverse rotation Y3 of the transport roller 16, the recording medium nipped between the transport roller pairs 16 and 17 is moved backward in the reverse feed and completely returns from the transport roller pairs 16 and 17 to exit. The holding of the recording medium between 17 is released (FIG. 5B).

In this case, the pickup roller 1 of the sheet feeding section
1 and the recording medium are in a released state, and the retraction of the recording medium is not hindered. The retraction of the recording medium is stopped when the leading edge of the recording medium completely returns from between the pair of conveying rollers 16 and 17.

10) After the release operation of the recording medium between the pair of transport rollers 16 and 17, the reverse rotation drive of the transport roller 16 is continued or the rotation drive is stopped, and 4) to 8 again. By performing the operation (2), the recording medium is nipped between the pair of transport rollers 16 and 17. However, step S5 is not passed and performed.

11) Nipping operation of the recording medium between the pair of conveying rollers 16 and 17 by the above operations 4) to 8) and nipping of the recording medium between the pair of conveying rollers 16 and 17 by the operation of 9) After the release operation is repeatedly performed a preset number of times (N1) (step S14),
Finally, the transport roller 16 is rotated forward Y4 to transport the recording medium to the recording position (step S15), and the recording operation is performed.

Thus, as described in the section of the operation, the recording medium P sent out from the sheet feeding section by the feeding means has the burr a at the end of the sheet. As a result, the recording medium P
By performing the pinching operation and the pinching-releasing operation on the pair of conveying rollers by the forward / reverse control of 17, or the repetition of the pinching operation and the pinching-releasing operation a plurality of times, as shown in FIG. The burr a is crushed and the recording medium P
Variations in paper thickness between sheets are reduced. Therefore, the biting of the recording medium P between the transport roller pairs 16 and 17 is stabilized between the recording media, and finally the transport roller pair 16
・ It is possible to reduce the variation in the biting property of the recording medium between the pair of transport rollers, which is caused by the variation in the paper thickness between the recording media conveyed to the recording unit while being sandwiched between the recording media 17, so that the transport amount can be reduced as compared with the conventional apparatus. It is possible to carry with little variation.

Also, in the case of a recording medium having a folded portion or a wavy shape such as an envelope, the recording medium is similarly held in the conveyance roller pair by the forward / reverse control of the conveyance roller pair in the recording medium conveyance correction mode. The bulging portion of the folded portion b is crushed as shown in FIG. 9B by performing a plurality of repetitive operations of the operation and the pinching release operation, so that the paper thickness becomes substantially smaller than the initial time and the paper thickness becomes smaller. Variations are also reduced. In addition, the wavy shape is corrected, and the partial sticking of the recording medium between the pair of transport rollers 16 and 17 is also eliminated.
And the amount of slip between the recording medium and the recording medium decreases. Therefore, the biting of the recording medium between the conveying roller pairs 16 and 17 is stabilized between the recording media, and finally the conveying roller pair 16
17 can reduce the variation in the sticking property of the recording medium between the pair of transporting rollers caused by the variation in the paper thickness between the recording media conveyed to the recording unit while being sandwiched between the recording media 17 and the variation in the transport amount as compared with the conventional apparatus. Can be conveyed.

Thus, even when the recording medium to be passed through the apparatus is thick paper such as a postcard, an envelope, or the like, the amount of slip between the transport roller and the recording medium is stabilized between the recording media, and the transport of the paper at the paper feeding section is performed. Variations in the conveyance amount of the recording medium with respect to the recording section, which occur at the roller pair, can be reduced to eliminate a recording position deviation error on the recording medium.

In order to compare the effect of the present invention with a conventional apparatus (a recording apparatus without a recording medium conveyance correction mode), the apparatus according to the present invention is applied to a case where a recording medium to be passed through the apparatus is thick paper such as a postcard or an envelope. FIG. 10 shows the degree of variation in the recording medium conveyance amount between the conventional apparatus and the conventional apparatus.

(4) Relationship between Conveyance Roller Diameter and Recording Medium Biting Performance FIG. 11 is a diagram showing the relationship between the conveyance roller diameter and recording medium biting performance depending on the paper thickness.

When the diameter of the conveying roller 16 is large (a) and small (b), when the recording medium P has the same paper thickness, the larger the diameter of the conveying roller 16 is, the larger the diameter of the conveying roller 16 becomes. Contact angle θ at the biting position of the medium
Becomes smaller (θ1 <θ2). Therefore, the transport roller 16
When the is rotated, the force for propelling the recording medium P in the transport direction is increased, and the bite is improved. Conversely, the bite decreases as the diameter of the transport roller 16 decreases.

FIG. 12 is a graph showing a variation in the transport amount of the recording medium due to a difference between the diameter of the transport roller and the thickness of the recording medium.

The graph shows the variation in the transport amount when the transport roller diameter is sufficiently large with respect to the paper thickness.

As the diameter of the transport roller is reduced from this state, the variation in the transport amount changes from a graph to a graph.

When the allowable range of the variation of the transport amount is set, the variation of the transport amount tends to increase around a transport roller diameter of about 10 mm.

Therefore, the recording medium conveyance correction mode according to the present invention is particularly effective for a recording medium having a conveyance roller diameter of about 10 mm or less.

(5) Others a) The present invention is particularly effective for recording media of thick paper,
By using a control sequence that executes the print medium transport correction mode only when thick paper such as postcards or envelopes is selected when a print medium is selected by a driver or the like, the transport of plain paper can be performed without the print medium transport correction mode. It becomes the same as the apparatus, and it is not necessary to unnecessarily increase the recording time.

B) The paper feed unit may be a manual feed type paper feed unit that manually feeds the recording medium one sheet at a time into the paper feed port and feeds it out by the feeding means.

C) The feeding means for sending out the recording medium from the sheet feeding unit and the release of the recording medium may be configured to move the feeding means away from the recording medium.

A pickup roller (feed roller) as a feeding means is a circular roller, which is supported on a drive shaft via a one-way clutch so that recording is performed in a direction opposite to the recording medium feeding direction so as to run idle. It is also possible to cope with the backward movement of the medium.

D) The configuration of the recording means for the recording medium is arbitrary.

[0105]

As described above, according to the present invention, the recording medium sent out from the sheet feeding unit by the feeding means is sandwiched between the pair of conveying rollers of the sheet feeding unit, conveyed to the recording unit, and transferred to the recording medium. In a recording apparatus that performs recording, even when the recording medium used for passing through the apparatus is thick paper such as a postcard or an envelope, the variation in the transport amount of the recording medium to the recording section that occurs at the pair of transport rollers in the paper feeding section is reduced. By performing stable conveyance, it is possible to eliminate a recording position deviation error on a recording medium.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an example of a recording apparatus according to the present invention.

FIG. 2 is a schematic configuration diagram of an internal mechanism.

FIG. 3 is a block diagram of a control system.

FIG. 4 is a diagram illustrating an operation process of the apparatus when the recording medium conveyance correction mode is executed (part 1).

FIG. 5 is a diagram illustrating an operation process of the apparatus when the recording medium conveyance correction mode is executed (part 2).

FIG. 6 is a flowchart of a control sequence performed by a control unit (part 1).

FIG. 7 is a flowchart of a control sequence performed by the control unit (part 2).

FIG. 8 is an explanatory diagram of the operation and effect of the recording medium conveyance correction mode (part 1).

FIG. 9 is an explanatory diagram of the operation and effect of the recording medium conveyance correction mode (part 2).

FIG. 10 is a diagram illustrating a degree of variation in a recording medium conveyance amount between the apparatus of the present invention and a conventional apparatus.

FIG. 11 is a diagram for explaining a relationship between a feeding roller diameter and a recording medium biting performance depending on a paper thickness;

FIG. 12 is a graph showing a variation in a conveyance amount of a recording medium due to a difference between a conveyance roller diameter and a sheet thickness of a recording medium.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 Pickup roller 12 Oscillating pressure plate 15 Movable bank 16.17 Conveying roller pair (conveying roller and pinch roller) 25.27, 27.28 Discharge roller pair 29 Recording head 30 Recording head carriage P Recording medium

Claims (9)

[Claims] 1. A printing apparatus for holding a recording medium sent from a paper feeding unit by a feeding means between a pair of conveying rollers of a paper feeding unit, conveying the recording medium to a recording unit, and performing recording on the recording medium. A recording medium clamping operation for clamping the recording medium sent out by the feeding means between the pair of transport rollers rotating in a normal direction, and after the recording medium clamping operation, reversing the pair of transport rollers to retract the clamped recording medium. After the recording medium conveyance correction mode in which the recording medium is released from the pair of conveyance rollers and the nip is released and the nip is released is performed a plurality of times, and the recording medium conveyance correction mode is executed, the recording medium Characterized in that the recording device is conveyed to a recording section while holding the recording medium. 2. The recording apparatus according to claim 1, wherein the paper feeding unit is an automatic paper feeding unit that separates and feeds the stacked recording media one by one or a manual paper feeding unit. 3. The recording apparatus according to claim 1, further comprising release means for releasing the feeding means and the recording medium. 4. The recording apparatus according to claim 1, wherein the feeding unit is a paper feed roller having a partially-circular shape. 5. A conveying roller pair of a paper feeding section is driven in a forward rotation
5. The recording apparatus according to claim 1, further comprising a transport roller driven in reverse rotation and an auxiliary roller urged against the transport roller by elastic means. 6. The recording apparatus according to claim 5, wherein the conveying roller has a diameter of about 10 mm or less. 7. The recording apparatus according to claim 1, wherein a feeding force is applied to the recording medium by a feeding unit during a recording medium holding operation for holding the recording medium between the pair of conveying rollers. apparatus. 8. A recording medium nipping releasing operation for reversing a pair of conveying rollers and retreating the nipped recording medium so as to return from the pair of conveying rollers and release the nipping is performed by the feeding means and the recording medium. The recording apparatus according to claim 1, wherein the recording is performed in a released state. 9. The recording medium conveyance correction mode is executed only when conveying a thick sheet in which a recording medium used for passing through the apparatus is a thick sheet. Recording device.