JPH07314850A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To make a distance between faces constant so as to heighten image quality by holding record heads on both side faces in a state that the distance between the faces does not approach-more than a specified value by a regulation section formed on a holding member. CONSTITUTION:At upper and lower proper parts of a regulating member 54 opposed to a regulating member 55, guide grooves 54a and 54b are formed. As an interval between the right end of the guide groove 54a and the left end of the guide groove 54b, a predetermined distance L1 is set. Likewise, at the positions of the regulating member 55 opposed to the guide grooves 54a and 54b, guide grooves 55a and 55b are formed. Four record heads 51a form a rectangular parallelepiped. At the top end of it and at both ends in the cross direction of a recording paper, protrusions 53a are formed ranging from the back end to a predetermined area. The protrusion 53a of each record head 51a engages with the guide grooves 54a and 55a at the upper side, and arranged slidably in the right and left directions between the regulating members 54 and 55. Thus. the distance between the faces of the record heads are kept constant, so that high quality of images can be maintained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus used in facsimiles, copying machines, printers and the like.

[0002]

2. Description of the Related Art Conventionally, an ink jet recording apparatus for ejecting ink from a recording head to print on a sheet has been put into practical use, and recently, an apparatus capable of printing from both sides of the sheet has been proposed. Kaihei 5-330037).

In the recording apparatus described in Japanese Unexamined Patent Publication (Kokai) No. 5-330037, the recording heads are arranged so as to face both sides of the recording paper, and the recording paper is conveyed between both recording heads to eject ink, Immediately after printing, almost the entire surface of the recording paper is attracted to the belt and conveyed. But,
A transport mechanism for accurately transporting the recording paper between both recording heads is not disclosed.

As such a conveying mechanism, a pair of conveying belts is provided on both sides in the width direction of the sheet, and both ends of the recording sheet in the width direction are sandwiched from both sides by the pair of conveying belts on both sides, and the sheet is conveyed by rotation of the belt. Can be considered. According to this double-sided feeding method, almost the entire surface of the paper is released,
The recording heads on both the front and back sides can be arranged facing each other at the same position in the paper transport direction.

On the other hand, it has been conventionally known that in an ink jet recording apparatus, high print quality can be obtained when the distance between the recording paper and the ink ejection surface of the recording head is about 1 mm or less.

[0006]

However, in order to obtain high print quality, it is necessary to maintain a constant distance between the ink ejection surfaces of the recording heads facing each other. Further, when the recording paper is conveyed in the gap between the two recording heads on the front and back sides, if the recording paper is bent by 1 mm or more, the paper comes into contact with the ink ejection surface of one of the recording heads. .
As a result, the printed image may flow, or the nozzle may be clogged to cause white streaks in the image, which may deteriorate the print quality.

Moreover, if the recording heads on both the front and back sides are arranged opposite to each other at the same position in the paper conveyance direction, it becomes difficult to remove the jammed paper when a paper jam (jam) occurs in the pair of conveyor belts.

An object of the present invention is to solve the above problems and to provide an ink jet recording apparatus which maintains a constant distance between the ink ejection surfaces of the recording heads facing each other.

Another object of the present invention is to provide an ink jet recording apparatus which improves the workability of jam processing.

Another object of the present invention is to provide an ink jet recording apparatus which conveys a recording paper while keeping a constant distance from the ink ejection surface of the recording head.

[0011]

In order to achieve the above object, the present invention performs recording by ejecting ink from a long recording head arranged on both sides of a recording sheet conveyed by a sheet conveying means. An inkjet recording apparatus for recording an image on both sides of a sheet is provided with a holding member for holding the recording heads on both sides, and the holding member has a surface distance between the recording heads on both sides separated by a predetermined value. A regulating portion is formed so as not to approach the position 1 (Claim 1).

Further, in the ink jet recording apparatus according to the first aspect, the cap held by the holding member at the second position facing the recording heads on both sides of the cap and the caps on both sides of the cap are provided. And a cap moving means for moving the recording head forward from the second position toward the opposite recording head to perform capping of the recording head (claim 2).

In the holding member, a movement path is formed in the backward direction from the first and second positions of the recording head and the cap on at least one side of the double-sided recording head and the cap. 3).

Further, in the ink jet recording apparatus according to a third aspect of the invention, the recording head and the cap are arranged in parallel with the holding member at the retracted position retracted from the first and second positions, and one end side in the longitudinal direction of the recording head and the cap. A retractable holding member for rotatably holding the supporting point is provided (Claim 4).

Further, the sheet conveying means is arranged on both sides of the recording sheet, and the both sides of the recording sheet in the width direction are in contact with each other, and both ends of the recording sheet in the width direction are held from both sides. A pair of conveyor belts that are conveyed in parallel, and a guide roller that is disposed in contact with the back side of each of the conveyor belts so as to face each other. Each guide roller is rotatably attached to the holding member. , And is arranged at least on the upstream side of the recording head (claim 5).

[0016]

According to the first aspect of the invention, the recording heads arranged on both sides of the recording sheet are held by the holding member so that the distance between the surfaces does not come closer than the first position separated by a predetermined value. Regulated by. Therefore, the surface distance between the recording heads on both sides is always constant, so that the image quality is maintained at a high level.

According to the second aspect of the present invention, the double-sided caps held by the holding member are moved forward from the second position toward the opposing recording heads to cap the recording heads. Be seen.

According to the third aspect of the invention, at least one side of the recording head and the cap on both sides can be moved backward from the first and second positions by the movement path, and the recording on one side can be performed. When the head and cap move backward, the distance between each recording head and each cap increases.

According to the fourth aspect of the invention, when the recording head and the cap retreated to the retracted position rotate about one end side in the longitudinal direction as a fulcrum, the recording head and the cap are opposed to each other. The spacing will be further increased.

According to the fifth aspect of the invention, the guide roller attached to the holding member prevents the conveyor belt from being bent and displaced at least on the upstream side of the recording head. Therefore, the image recording is performed with high quality.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the ink jet recording apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing the appearance of the device. FIG. 2 is a front view showing a schematic configuration of the inside of the device.

This device is, for example, a printer which prints character data or the like input from an external device. In FIG. 2, the paper storage unit consisting of the paper feed cassettes 21 to 24 is conveyed to the right in FIG. 2, and the recording paper is conveyed to the left. In addition, a printing unit 4 for printing on both the front surface and the back surface is provided, and a paper transport system 13 for transporting the paper from the right side to the left side is provided therebetween, and a sorter 8 is provided below the printing unit 4, respectively. There is. Sorter 8
Is for storing the printed recording paper by moving the bins 8a one by one in the horizontal direction by a spiral cam (not shown). Further, an operation panel 1 and a paper feed bypass unit 3 are arranged at appropriate places on the surface of the apparatus.

The operation panel 1 includes an operation section provided with a discharge recovery key for performing a discharge recovery operation, which will be described later, and an LCD.
And a LED and the like, and is configured by a display unit for displaying setting contents and the like. The paper feed bypass section 3 is for manually feeding paper by adjusting the width alignment mechanism 3a arranged on the surface of the apparatus to the paper width.

In the sheet storage section, sheet feed cassettes 21 to 24 having different sizes capable of storing cut sheets are stacked and arranged. In the paper feed cassettes 21 to 24, for example, A4 size recording paper is placed vertically in the paper feed cassette 21, A3 size is placed vertically in the paper feed cassette 22, and in the paper feed cassette 23 in the paper feed direction. The B4 size is oriented vertically,
The B5 size is horizontally stored in the paper feed cassette 24. The size and orientation of the paper stored in each cassette is not limited to the above.

The paper transport system 13 includes paper feed cassettes 21 to 21.
24 and the paper feed bypass section 3, which are provided corresponding to the paper feed rollers 31 to 34, 37 for feeding paper, a pair of conveyance rollers for conveying the paper, a conveyance guide for guiding the conveyance paper, a pair of registration rollers 38, etc. Is provided. The registration roller pair 38 nips the conveyed sheet, starts rotation after the skewed conveyance is corrected, and feeds the recording sheet to the printing unit 4. The rotation of the registration roller pair 38 and the image It is supposed to be done in synchronization with the recording,
The elapsed time from the start of rotation of the registration roller pair 38 is counted, and image recording is started after a predetermined time.

The printing unit 4 includes a pair of conveyor belts, which are composed of drive side conveyor belts (hereinafter, referred to as drive belts) 41 and 43 and driven side conveyor belts (hereinafter, referred to as driven belts) 42 and 44. It is composed of a paper transport mechanism for holding and transporting it, and a printing mechanism including four recording heads and cap portions arranged on both sides of the transport paper.

First, FIG. 3 showing the structure of a regulating member provided in the printing mechanism for regulating the position of the recording head.
~ It demonstrates using FIG. FIG. 5 shows a state in which the recording head 51a and the cap portion 52a are arranged on the regulating members 54 and 55, and the conveyor belts 43 and 44 and the belt moving plate 40 are shown.
Is omitted.

The restricting members 54 and 55 are the side plates 1 respectively.
It is fixed to Nos. 1 and 12 and is arranged at positions facing each other, and four sets are arranged at a required interval along the sheet conveyance path. The side plates 11 and 12 are arranged at both ends of the conveyed recording paper in the width direction and are fixed to the apparatus main body.

As shown in FIG. 3, the regulating member 54 has a guide groove 54a inward from the left end and a guide groove 54b inward from the right end at appropriate places on the upper and lower portions of the surface facing the regulating member 55.
Are formed respectively. The distance between the right end of the guide groove 54a and the left end of the guide groove 54b is set to a predetermined distance L1. Further, a hole 56a is formed at a proper position below the guide grooves 54a, 54a from the left end over a required range, and the guide grooves 54b, 54b are provided.
A hole 56b is provided at a proper position above the space from the right end over a required range,
Each is drilled.

The regulating member 55 has guide grooves 54a, 5a.
4b, guide grooves 55a, 55b are formed at positions facing the holes 4a, and holes 57a, 57 are formed at positions facing the holes 56a, 56b.
b is drilled.

Next, the recording heads 51a and 51b will be described with reference to FIGS. 6 and 7 are views showing the configurations of the recording head and the cap portion.

The four recording heads 51a have a rectangular parallelepiped shape and are located at the upper end and both ends in the width direction of the recording paper, and the rear end (see FIG. 6).
A protruding portion 53a is formed over a predetermined range from the left end in (a). Each recording head 51a has a protrusion 53a.
Is engaged with the upper guide grooves 54a and 55a, and is disposed between the regulating members 54 and 55 so as to be slidable in the left-right direction in FIG.

A head pressing member 58 is arranged immediately behind each recording head 51a as shown in FIG. The head pressing member 58 applies forward pressing force to the recording head 51a by the rotation of the pressing shaft 59. The head pressing member 58 has a base 6 fixed to the pressing shaft 59.
0, a pressing plate 61 that abuts on the rear end of the recording head 51a, and a coil spring 6 fixed between the pressing plate 61 and the base 60.
It consists of two. The presser shaft 59 is provided on the side plates 11 and 12
It is rotatably supported between and is connected to a head pressing motor 64 via a gear transmission mechanism 63. The head pressing motor 64 is arranged on the side plate 11 and rotates the pressing shaft 59 via the gear transmission mechanism 63.

When the pressing shaft 59 is rotated counterclockwise in FIG. 5A by the head pressing motor 64 and the pressing plate 61 is moved to the pressing position shown by the solid line in FIG. 8, the coil spring 62 is moved. The recording head 51a is pushed forward by the pressing plate 61 by the elastic force of the recording head 51a, and the recording head 51a is fixed at the position where the protruding portion 53a abuts the tips of the guide grooves 54a, 55a of the regulating members 54, 55. It will be.

On the other hand, the head pressing motor 64 causes the pressing shaft 59 to rotate in the clockwise direction in FIG.
When 1 moves to the retracted position shown by the chain double-dashed line in FIG. 8, the recording head 51a becomes slidable to the left.

The four recording heads 51b have the same rectangular parallelepiped shape, and are at the lower end and at both ends in the width direction of the recording paper, and projecting portions 53b over a predetermined range from the rear end (the right end in FIG. 7A).
Are formed. Each recording head 51b has a protruding portion 53.
b engages with the guide grooves 54b and 55b on the lower side, and as shown in FIG.
4b, 55b at the position where it abuts the left end of the restriction member 54,
It is fixed between 55 respectively.

The recording heads 51a and 51b are long in the width direction of the recording paper to be conveyed, and the ink ejection surface S is provided with a nozzle row in which, for example, minute diameter nozzles are arranged in a row at a predetermined pitch. ing. Then, for example, it is composed of a piezoelectric element, and ink is ejected from the nozzles toward the recording paper by an ink ejection mechanism provided in each nozzle to print an image on both sides of the recording paper. The nozzle row dimensions are
For example, the short side of A3 size paper is set to a printable value.

The recording heads 51a and 51b eject yellow (Y), magenta (M), cyan (C), and black (BK) ink in this order from the upstream side in the paper transport direction. Inks are sequentially ejected,
It is designed to print in color.

In this way, the recording heads 51a and 51b are arranged on the regulating members 54 and 55, and their guide grooves 54a and 54 are formed.
Since the position is regulated at the end of b, the recording head 5
The distance between the ink ejection surfaces S of 1a and 51b can be maintained constant. Further, since the pressing plate 61 is rotatable to the retracted position, the recording head 51a can be disengaged from the restricting members 54 and 55 by manually sliding the recording head 51a to the left in FIG. Therefore, when a paper jam (jam) occurs, it is possible to improve the workability such as jam processing for removing the jammed paper.

The recording heads 51a and 51b may be composed of a plurality of nozzle rows in which the nozzles are staggered and arranged. Alternatively, only one recording head 51a, 51b for ejecting black (BK) ink may be provided to enable black-and-white printing.

Next, the cap portions 52a, 52b will be described with reference to FIGS. 2, 6, 7, 9 and 10. FIG. 9 is an exploded perspective view showing the positional relationship between the recording head and the regulating member. FIG. 10 is a plan view showing the support mechanism of the cap portion 52a.

The cap portion 52a is for each recording head 51a.
6 in FIG. 6, the cap portion 52b is arranged side by side on the lower side.
7 are arranged in parallel on the upper side of each recording head 51b in FIG. 7, and the recording head 51a and the cap portion 52b, and the recording head 51b and the cap portion 52a are arranged at positions facing each other.

Each of the cap portions 52a and 52b has a rectangular parallelepiped shape and is provided with a cap 71 made of, for example, rubber or soft synthetic resin. When the printing is not performed, the recording heads 51b and 51a facing the cap 71 are capped. It is intended to prevent the solidification of the ink at the nozzle tip and the invasion of foreign matters, bubbles and the like into the nozzle.

In the capping state, suction is performed by a suction means (not shown) to return the meniscus formed at the tip of the nozzle to a normal position, or to remove air bubbles and foreign matters in the nozzle together with the ink, thereby causing ink ejection failure. A discharge recovery operation such as to eliminate the above is performed.

Further, during printing, the feeding of the recording paper to the printing unit 4 is temporarily stopped at a required interval, and the conveyor belts 41 to 44 are temporarily retracted from the nozzle row to both outsides by a belt moving mechanism described later. By performing the idle ejection in which ink is ejected from all the nozzles of the recording heads 51a and 51b toward the cap 71, clogging of nozzles that are not used during printing or that are rarely used is prevented. The blank discharge may be performed in a capping state.

At the lower end of the cap portion 52a and at both ends in the width direction of the recording paper, a protruding portion 72a is formed over a predetermined range from the rear end (the left end in FIG. 6A), and the protruding portion 7a is formed.
2a is a guide groove 54a, 5 below the regulating member 54, 55
5a is engaged.

Further, the cap portion 52a has projections 73a formed at appropriate positions on both side surfaces in the width direction. The protrusion 73a is
It has a columnar shape with a recess at the tip, and the magnet 7
5 is buried. The rack 74a includes side plates 11 and 12
Are arranged on both outer sides, have a required size, and are movably supported in the longitudinal direction. Further, a cylindrical outer casing 76 is fixed on the rack 74a at a position facing the protrusion 73a, and a protrusion member 77 is arranged inside thereof. The projecting member 77 has a magnet 75 and a magnet 78 having a different polarity embedded in the front end thereof, and a rear end thereof connected to the surface of the rack 74a by a coil spring 79, and is slidably arranged in the external housing 76.

The cap portion 52a includes a magnet 75,
The magnetic force of 78 and the projecting member 77 are semi-fixedly supported by the racks 74a on both sides by the elastic force of the coil spring 79 that presses the projecting 73a.

In this way, the cap 52a is attached to the magnet 7
Since the racks 74a are supported in a semi-fixed state by the magnetic forces of 5, 78 and the elastic force of the coil spring 79, the cap portion 52a can be manually removed from between the racks 74a and separated from the restricting members 54, 55. it can. Therefore, the workability of the jam processing can be improved.

On the other hand, the cap portion 52b is located at the upper end and both ends in the width direction of the recording paper, and the rear end (the right end in FIG. 7A).
A projection 72b is formed over a predetermined range from the projection 72b to the guide groove 54 above the restriction members 54 and 55.
a, 55a. Also, the cap portion 52b
Is similar to the cap portion 52a, the magnetic force of the magnets 75 and 78 and the coil spring 7 in which the protrusion member 77 presses the protrusion 73b.
It is supported by the racks 74b on both sides in a semi-fixed state by the elastic force of 9 and can be manually removed from between the racks 74b. The rack 74b is arranged parallel to the rack 74a on both outer sides of the side plates 11 and 12, has a required size, and is supported so as to be movable in the longitudinal direction.

The racks 74b and 74a are meshed with a disk-shaped pinion 65 from above and below. Each pinion 65 is directly connected to and supported by a cap moving motor 66. By rotating both pinions 65 in the same direction, the cap portions 52a and 52b are moved forward and backward via the racks 74a and 74b.

Next, the movement operation of the cap portions 52a and 52b having the above-mentioned structure will be described. When the printing operation is completed, first, the drive belts 41 and 43 and the driven belts 42 and 44 are moved from the nozzle row to both outsides by the movement mechanism described later. Next, the cap moving motor 66
9, the pinion 65 rotates counterclockwise in FIG. 9, the racks 74a and 74b move, the cap portions 52a and 52b move forward, and the cap 71 caps the recording heads 51b and 51a. Done.

On the other hand, when starting the printing operation, first,
The pinion 65 rotates clockwise in FIG. 9 and the racks 74a and 74b move, so that the cap portion 52
The capping is released by the backward movement of a and 52b.

As described above, the pinion 65 is rotationally driven to move the cap portions 52a and 52b forward and backward, so that the cap 71 of the recording heads 51a and 51b facing each other can be capped and released.

It should be noted that the projection 73b is formed into a cylindrical shape and is directly fixed to the rack 74b so that the cap portion 52b has the rack 74b.
You may comprise so that it may be supported in the state which cannot be removed from between.

Next, the holding frame and the retractable holding member will be described with reference to FIGS. 5 and 11 to 15. The retractable holding member is the recording head 5 separated from the regulating members 54 and 55.
1a and the cap portion 52a are held, and the holding frame body holds the retractable holding member. FIG. 11 shows a state in which the recording head 51a and the cap portion 52a are held by the retractable holding member. 12 and 13 show the holding frames 131 and 132, and FIGS. 14 and 15 show the retractable holding member.

The holding frame members 131 and 132 are arranged at positions facing each other, and are arranged adjacently to the left side of the regulating members 54 and 55 in FIG. 5, and the side plates 11 and 1 respectively.
It is fixed to No. 2 and holds the retractable holding member 137.

The holding frame 131, as shown in FIG.
It has a U-shape in a front view and a side view, and the small holes 133 are formed at appropriate positions substantially at the centers of the upper surface and the lower surface at the same position in a plan view.
134 are respectively drilled. Also, the holding frame 1
As shown in FIG. 13, the reference numeral 32 has a shape symmetrical with the holding frame 131, and has small holes 135 and 136 formed in the upper and lower surfaces thereof.

As shown in FIG. 14C, the retractable holding member 137 has U-shaped frame portions 142 and 143 which are U-shaped in left and right in a side view.
And the columnar, short-sized protrusions 13 at substantially the proper positions in the center of the upper and lower surfaces of the frame 142 at the same position in plan view.
8, 139 are formed. Further, recesses are provided at appropriate positions substantially in the center of the upper surface and the lower surface of the frame portion 143 in the same position in plan view, and the small balls 140, 141 are disposed in the recesses. The small spheres 140, 141 are connected to the bottom surface of the recess by an elastic member (not shown) such as a spring. When a pressing force is applied from the inside, the retractable holding member 137 is immersed.

The retractable holding member 137 has the projection 13
8, 139 in the small holes 133, 134, small balls 140, 14
When 1 is engaged with the small holes 135, 136, it is held by the holding frame bodies 131, 132.

The retractable holding member 137 is shown in FIG.
The width dimension L2 in (b) is formed to be substantially the same as the widths of the recording head 51a and the cap portion 52a.
As shown in (c), guide grooves 144 and 145 are formed above and below the inner side surfaces of the frame portions 142 and 143. The guide grooves 144 and 145 are the guide grooves 54 of the regulating members 54 and 55.
a and 55a are formed on the same straight line. Further, the retractable holding member 137 is provided with the holes 56a of the regulating members 54 and 55,
Holes 146 and 147 of required dimensions are formed on the same straight line as 57a.

The recording head 51a and the cap portion 52a, which are manually separated from the regulating members 54 and 55, are
As shown in FIG. 11, each protrusion 53 a and protrusion 7
By engaging 2a with the guide grooves 144 and 145, respectively, their movement is guided and held.
It should be noted that the cap portion 5 that moves due to the holes 146 and 147.
The protrusion 73a of 2a does not interfere.

Next, when a rotational force is applied to the retractable holding member 137 in the clockwise direction about the protrusions 138 and 139, the small balls 140 and 141 are once retracted and the small holes 135 and 138 are inserted, as shown in FIG. The engagement with 136 is released, and the retractable holding member 137 is released from the holding frame body 132.

Thus, the small ball 1 of the retractable holding member 137 is
40 and 141 are arranged so as to be retractable from the surface and are held in the holding frame body 132 in a semi-fixed state, so that the retractable holding member 137 is detached from the holding frame body 132 by manually applying a rotational force. Can be made. Therefore, the workability of the jam processing can be further improved.

The holding frame body 131 and the regulating member 54, and the holding frame body 132 and the regulating member 55 may be integrally formed.

Next, the paper transport mechanism will be described with reference to FIGS.
6, and FIG. 17 will be described. FIG. 16 shows the printing unit 4
The side plate 12 is omitted in the front view of FIG. FIG. 17 shows FIG.
Of the drive belts 41 and 43 and the transport belt moving plates 39 and 40, only the drive mechanisms of the drive belts 41 and 43 are shown, and other components such as the pulleys 84 and 85 and the regulating members 54 and 55 are omitted. There is.

The drive belts 41 and 43 include a drive pulley 80, pulleys 81 to 84, and an idle roller 8 respectively.
It has an endless shape stretched over 5. Drive belt 4
In Nos. 1 and 43, chloroprene rubber is added to a meshless fabric made of polyester, for example, and the elongation is small and stable conveyance is possible.

The driven belts 42 and 44 have an endless shape stretched around the pulleys 90 to 94 and the idle rollers 95, respectively. The driven belts 42, 44 are made of urethane rubber, for example, and have large expansion and contraction, and the drive belts 41, 44
43 is formed of a material that easily fits.

The idle rollers 85, ..., 95 are arranged above and below the regulating members 54, 55, that is, at five locations, and prevent the conveyor belts 41 to 44 from bending and prevent them from being displaced. The frictional force with the belts 41 to 44 is driven to rotate.

The width of the conveyor belts 41 to 44 is, for example, 15
The recording sheet is formed to have a width of mm, and is sandwiched between both ends in the width direction of the recording sheet by a pair of conveying belts including a driving belt and a driven belt.

The pair of pulleys 81 to 84 and the pair of pulleys 90 to 94 respectively include the transport belt moving plates 39 and 4.
It is rotatably arranged at zero. The pulley 80 is shown in FIG.
As shown in FIG. 5, the drive shaft 804 is fitted and the transfer belt moving plates 39 and 40 are rotatably arranged.
The conveyor belt moving plates 39 and 40 are movable in the paper width direction by a moving mechanism described later.

The drive shaft 804 is rotatably supported by the side plates 11 and 12 and has a D-shaped cross section.
Both pulleys 80 are rotated with the rotation of 4. The drive shaft 804 is composed of gears 801 and 802, and the conveyor belt motor 8 is, for example, a stepping motor.
It is connected to 03. Then, the drive shaft 804 is rotationally driven by the conveyor belt motor 803 via the gears 801, 802, the pulley 80 is rotated, and the drive belts 41, 4 are rotated.
3 is rotationally driven. The driven belts 42 and 44 are adapted to rotate by being driven by the frictional force with the drive belts 41 and 43. Also, the pulley 80
The rotation amount and speed, that is, the transport distance and transport speed of the recording paper are controlled by the drive pulse supplied to the transport belt motor 803.

With the above configuration, when the drive shaft 804 rotates, the recording paper fed from the registration roller pair 38 to the printing unit 4 is between the pulleys 81 and 91, for example, 5 mm wide at both ends in the width direction, respectively. Drive belts 41, 4
3 and the driven belts 42 and 44. Then, it is conveyed in the P direction while being held between the pulleys 81 and 91 and the pulleys 80 and 90 by being sandwiched between the drive belts 41 and 43 and the driven belts 42 and 44.

In this manner, the widthwise ends of the recording paper are sandwiched between the drive belts 41 and 43 and the driven belts 42 and 44 from between the pulleys 81 and 91 to between the pulleys 80 and 90. Can be reliably transported.

Next, the belt moving mechanism for the conveyor belts 41 to 44 will be described with reference to FIGS.

The pair of conveyor belt moving plates 39, 40 are supported by the main body of the apparatus so as to be movable in the paper width direction, and the positions of the conveyor belts 41 to 44 are changed according to the size of the recording paper.

The transport belt moving plates 39, 40 are provided with shaft holes for rotatably holding the respective pulleys and idle rollers, and the square holes 39 for avoiding the respective regulating members 54, 55.
1 is provided. Further, shaft holes are formed at appropriate positions at both ends of the central portion, and tubular bearing members 418 and 419 are fixedly installed in the shaft holes.

Bearing member 4 of the conveyor belt moving plates 39, 40
The conveyor belt support shaft 422 supported by the side plates 11 and 12 is fitted into the bearing member 19, and the bearing member 418 is fitted into the bearing member 418.
Transport belt moving shaft 421 rotatably supported by 2
Are engaged with each other, and the conveyor belt moving plates 39 and 40 are held by the conveyor belt support shaft 422 and the conveyor belt moving shaft 421.

The bearing member 419 is used for the conveyor belt support shaft 42.
2 is designed to slide smoothly on the top. Bearing member 4
18 and the conveyor belt moving shaft 421, a female screw is formed on the inner surface of the bearing member 418, and a male screw is formed over the required range on the outer surface of the conveyor belt moving shaft 421.
It has a ball screw structure. Conveyor belt moving shaft 421
The screws are formed in different directions with the central portion as a boundary, and the transport belt moving plates 39 and 40 move closer to and away from each other by the rotation of the transport belt moving shaft 421.

The gear 423 fixed to the conveyor belt moving shaft 421 is meshed with the gear 424 of the belt moving plate motor 425. The belt moving plate motor 425 is composed of, for example, a stepping motor, and rotates the conveyor belt moving shaft 421 via the gears 424 and 423. The conveyor belt moving plates 39 and 40 are rotated by reversing the moving shaft 421. It can be moved according to the width of the recording paper. The rotation amount of the conveyor belt moving shaft 421, that is, the moving distance of the conveyor belt moving plates 39, 40 is controlled by the drive pulse supplied to the belt moving plate motor 425.

As described above, since the conveyor belt moving plates 39 and 40 enable the pulleys and the conveyor belts to be integrally moved in the paper width direction in accordance with the paper width of the recording paper to be printed, various papers can be used. According to the size, the drive belts 41 and 43 and the driven belt 4 are provided at both ends in the width direction of the recording paper, respectively.
The pair of transport belts 2 and 44 can securely sandwich and hold the sheet to transport the sheet.

It should be noted that the conveying belt pair moved in the width direction depending on the size of the recording paper may be only one of the conveying belt pairs. The other pair of conveyor belts, which do not move according to the paper size, may be moved to the outside of the nozzle unit 6 only during the capping operation or the idle discharge operation. In this case, the other pair of conveyor belts can shorten the required moving distance.

A guide roller may be arranged on the regulating member. Guide rollers 246, 247
As shown in FIG. 18, is disposed at the upper and lower ends of the regulating member 55 at positions facing the drive belt 43 and the driven belt 44 so as to project a predetermined distance from the ink ejection surfaces of the recording heads 51a and 51b. At the same time, it is rotatably arranged. Although not shown in the figure, the regulating member 54 is also provided with a guide roller at a position facing the drive belt 41 and the driven belt 42. These guide rollers can more reliably prevent the conveyance belts 41 to 44 from being bent and displaced. The guide roller may be provided only on the upstream side of each recording head 51a.

Further, as shown in FIG. 19, a guide roller may be arranged in the casing of the recording head. Figure 1
In No. 9, the guide rollers 148a and 148b are arranged at the upper and lower ends of the casings of the recording heads 51a and 51b so as to face the drive belt 43 and the driven belt 44 and protrude from the ink ejection surface by a predetermined distance. , Is rotatably arranged. Similarly, guide rollers are arranged at positions facing the drive belt 41 and the driven belt 42. With these guide rollers, the conveyor belt 4
It is possible to more reliably prevent the flexure and the positional displacement of 1 to 44.

[0085]

As described above, according to the first aspect of the present invention, the recording heads on both sides are moved from the first position where the inter-face distance is separated by a predetermined value by the restricting portion formed on the holding member. Since the print heads are regulated so as not to approach each other and held, the face-to-face distances of the print heads on both sides can always be made constant, so that the image quality can be kept high.

Further, according to the invention of claim 2, the both-side caps held by the holding member are moved forward from the second position toward the facing recording head.
The recording head can be capped and protected.

According to the third aspect of the invention, since the moving path is formed in the backward direction from the first and second positions on at least one side of the recording heads on both sides and the cap, the recording heads on one side and The cap can be moved backward from the first and second positions, and the distance between each recording head and each cap can be increased. Therefore, the workability of the jam processing can be improved.

Further, according to the invention of claim 4, the recording head and the cap retreated to the retracted position are rotatably held by the retractable holding member with one end side in the longitudinal direction as a fulcrum. The distance between each recording head and each cap can be further increased. Therefore, the workability of the jam processing can be further improved.

Further, according to the invention of claim 5, since the guide roller is attached to the holding member and is arranged at least on the upstream side of the recording head, it is possible to reliably prevent the conveyance belt from being bent and displaced. Therefore, a high quality image can be obtained.

[Brief description of drawings]

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

FIG. 2 is a front view showing a schematic configuration of the inside of the apparatus.

FIG. 3 is a view showing a regulation member 54, (a) is a front view,
(B) is a plan view, (c) is a left side view, and (d) is a right side view.

FIG. 4 is a view showing a regulation member 55, (a) is a front view,
(B) is a plan view, (c) is a left side view, and (d) is a right side view.

5A and 5B are views showing a recording head and a cap portion arranged on a regulation member, FIG. 5A is a front view and FIG. 5B is a plan view, and a recording head 51a and a cap portion 52a are arranged on the regulation member. ing.

6A and 6B are diagrams showing a recording head 51a and a cap portion 52a, FIG. 6A is a front view, FIG. 6B is a plan view, and FIG. 6C is a left side view.

7A and 7B are views showing a recording head 51b and a cap portion 52b, in which FIG. 7A is a front view, FIG. 7B is a plan view, and FIG. 7C is a right side view.

FIG. 8 is a view showing a head pressing member, (a) is a front view,
(B) is a plan view.

FIG. 9 is an exploded perspective view showing a positional relationship between a recording head and a regulation member.

FIG. 10 is a plan view showing a holding mechanism of a cap portion 52a.

11A and 11B are views showing a recording head and a cap portion arranged on a regulating member, FIG. 11A is a front view, and FIG. 11B is a plan view.
The recording head 51a and the cap portion 52a are arranged on the retractable holding member.

12A and 12B are views showing a holding frame 131, FIG. 12A is a front view, FIG. 12B is a plan view, FIG. 12C is a right side view, and FIG.

13A and 13B are views showing a holding frame body 132, where FIG. 13A is a front view, FIG. 13B is a plan view, and FIG. 13C is a right side view.

14A and 14B are views showing a retractable holding member 137, where FIG. 14A is a front view, FIG. 14B is a plan view, FIG. 14C is a right side view, and FIG.

FIG. 15 is a plan view showing a state in which a retractable holding member 137 is separated from a holding frame body 132.

16 is a front view of the printing unit 4. FIG.

FIG. 17 is a view on arrow A in FIG.

FIG. 18 is a front view showing a different configuration example of the regulation member 55.

FIG. 19 is a front view showing a different configuration example of the recording heads 51a and 51b.

[Explanation of symbols]

 11, 12 Side plates 51a, 51b Recording heads 52a, 52b Cap portions 54, 55 Restricting members 54a, 54b, 55a, 55b Guide grooves 65 Pinion 71 Caps 74a, 74b Racks 131, 132 Holding frames 137 Retracting holding members

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location B41J 3/54 13/08 25/304 B41J 3/04 102 N 25/30 U (72) Inventor Koji Kado 1-2-2, Tamatsukuri, Chuo-ku, Osaka Mita Kogyo Co., Ltd. (72) Inventor Kenichi Satake 1-2-2, Tamatsukuri, Chuo-ku, Osaka Mita Kogyo (72) Inventor Hiromi Kosaka 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Kogyo Co., Ltd. (72) Inventor Koichi Baba 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Kogyo Co., Ltd. (72) Inventor Masayuki Ishii 1-22 Tamatsukuri, Chuo-ku, Osaka Mita Kogyo Co., Ltd. (72) Inventor, Yoshiko Kawachi 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Kogyo Co., Ltd.

Claims (5)

[Claims] 1. An inkjet recording apparatus for recording an image on both sides of a recording sheet by ejecting ink from a long recording head disposed on both sides of the recording sheet conveyed by a sheet conveying means. A holding member for holding the recording head, and the holding member is provided with a restricting portion for restricting the inter-face distance of the recording heads on both sides from approaching a first position separated by a predetermined value. An ink jet recording apparatus characterized by being provided. 2. The ink jet recording apparatus according to claim 1, wherein the holding member holds the cap on the double-sided side at a second position facing the recording heads, and the double-sided cap. An inkjet recording apparatus comprising: a cap moving unit that moves the recording head from the second position toward an opposing recording head to cap the recording head. 3. The holding member has a movement path formed in a retreating direction from the first and second positions of the recording head and the cap on at least one side of the double-sided recording head and the cap. The inkjet recording apparatus according to claim 2. 4. The ink jet recording apparatus according to claim 3, wherein the recording head and the cap are arranged in parallel with the holding member at the retracted position retracted from the first and second positions, and one end side in the longitudinal direction of the recording head and the cap. An inkjet recording apparatus, comprising: a retractable holding member that pivotally holds a supporting point. 5. The paper conveying means is arranged on both sides of the recording paper, and is arranged so that the front surfaces of the recording paper come into contact with both sides of the recording paper in the width direction. A pair of conveyor belts that are conveyed in parallel, and a guide roller that is disposed in contact with the back side of each of the conveyor belts so as to face each other. Each guide roller is rotatably attached to the holding member. The inkjet recording apparatus according to any one of claims 1 to 4, wherein the inkjet recording apparatus is arranged at least on the upstream side of the recording head.