JPH0286474A - Liquid jet recorder - Google Patents

Abstract

PURPOSE:To prevent the leading end of a recording material from being caught by a head by providing a plate-shaped pressing member having only one end attached to a belt and having the other end in a free condition, and providing magnetic forces between the belt and the pressing member so that the belt and the pressing member attract each other in a sticking manner at a flat surface part of the belt, whereas the pressing member is levitated from the belt at a curvature part of the belt. CONSTITUTION:When a pressing member 12 is levitated from a belt 6 at a curvature part of the belt 6, a recording material is supplied between the belt 6 and the pressing member 12. When the belt 6 becomes flat concurrently with a feeding to a recording position, the pressing member 12 and the belt 6 are attracted to each other by magnetic forces to grip the recording material therebetween. Thus, the recording material is brought into close contact with the belt 6, the leading end of the recording material is not caught by any of recording heads 1a-1d, and paper jamming does not occur. The belt 6 is formed of a magnet rubber, and the pressing member 12 is formed of a magnetic material.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a liquid jet recording device, and more specifically, the present invention relates to a liquid jet recording device, and more specifically, the present invention relates to a liquid jet recording device, and more specifically, the present invention relates to a liquid jet recording device, and more specifically, a recording liquid (hereinafter referred to as ink) ejection port is connected to a recording material (hereinafter referred to as recording material) such as paper or a plastic sheet. The present invention is particularly suitable for application to a liquid jet recording apparatus that records on a cut sheet of recording paper.

[Prior Art] A liquid jet recording apparatus has been proposed that records information such as characters and images by ejecting ink from a recording head.

Conventionally, among these types of devices, in those in which the recording head is mounted on a carriage and performs serial scanning while recording, there are several A guide is provided,
These prevent the recording paper from floating up.

On the other hand, in devices equipped with a line-shaped recording head, the recording paper is conveyed in a straight line along a table with negative pressure inside while applying appropriate tension to the recording paper. has been done. Although this method is effective as a method for conveying recording paper in the form of continuous paper such as roll paper and fanfold paper, there is an increasing demand for recording on cut sheets as recording paper becomes more widely used.

Therefore, a method has been proposed in which a conveyor belt is used and the recording paper is electrostatically attracted to the belt to convey the recording paper.

[Problems to be Solved by the Invention] However, in such a configuration, conventionally, only electrostatic adhesion force was used as a restraining force on the recording paper, so that the recording paper was not prone to curling or bending. As a result, the edge of the recording paper, which tends to lift up from the belt surface, gets caught on the head during conveyance during the recording operation, which may stain the recording paper or damage the recording head.

An object of the present invention is to prevent such inconvenience by enabling reliable conveyance regardless of the state of the recording paper.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a liquid jet recording apparatus that performs recording by ejecting a recording liquid onto a recording material, in which a belt is used as a means for conveying the recording material. and a presser member whose front end in the conveyance direction is fixed to the belt member and the other part is not fixed. The members are attracted to each other along the belt member, and in the region where the belt member has a curvature, a magnetic force exists to the extent that the holding member floats therefrom.

[Function] According to the present invention, the recording material is supplied when the belt member is at the curved portion and the presser member is floating, and then the belt member becomes flat as it is conveyed to the recording position. Sometimes, the presser member and the belt member attract each other, and the recording material is gripped between them. As a result, the leading edge of the recording material, which is particularly prone to floating, is reliably brought into close contact with the surface of the belt member.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the invention.

Here, l is a line head type recording head, and 3456 ejection ports are provided on the lower surface at intervals of, for example, 16 dots/ram, and recording with a width of 21 BIDm is performed line sequentially. In this example, yellow, cyan,
Compatible with four colors of ink: magenta and black,
Four recording heads, la, lb, lc, and ld, are provided, and each recording head is fixedly supported by a holder 2 so that the distance between the ejection ports in the recording paper conveyance direction is constant. . The head unit composed of these four recording heads and the holder 2 can be moved up and down in the figure by a head moving means 24 comprising a drive source such as a motor and a transmission mechanism such as a gear.

A cap 3 is attached to the orifice surface of the recording head when not recording, and is movable in the X direction by a cap moving means 25 comprising a drive source such as a motor or a transmission mechanism such as a gear. The cap 3 has an ink absorbing member, for example a sponge, inside, and is configured to receive ink ejection (idle ejection) from the recording head 1 for a recovery operation.

Reference numeral 4 indicates an ink tank corresponding to each recording head, and ink is guided to each recording head 1' (la-1d) via an ink supply tube 5 (58 to 5dl).

Here, ink is supplied using capillary action of nozzles disposed in the recording head 1, and the ink water head of each ink tank is set a certain distance lower than the ejection port surface.

Reference numeral 6 designates a belt for conveying the recording paper, and in this example, this belt is constructed using magnetic rubber.
As shown in the figure, a plurality of openings are provided. Reference numeral 12 is a plate-shaped paper presser member whose one end edge on the front side in the direction of movement is fixed on the belt 6 and the other edge side is free. It is made of magnetic material.

The belt 6 is rotated by a motor 8 connected to a belt drive roller in a direction to move the recording paper 27 in the X direction. Then, the belt position is detected by a photosensor 121 that detects an opening provided in the belt 6 via a detection circuit 122. Reference numeral 9 indicates an idle roller for turning the belt 6, and reference numeral 10 indicates a tension roller for applying a constant tension to the belt 6. 11 is a pinch roller that presses the recording paper 27 against the belt 6 to strengthen suction;
The roller 11 and the belt of the roller 9a part receive and stop the fed recording paper 27, loop it within the guide 13, and also function as registration rollers that improve the perpendicularity of the leading edge of the recording paper with the X direction. .

The recording paper 27 is fed one by one from the cassette 26 by the paper feed roller 16, is sandwiched between the conveyance roller 14 and the pinch roller 15, and guided to the portion corresponding to the registration roller described above. 17 is a cleaning unit, and belt 6
Remove paper dust, etc. on top. Further, 18 is a paper discharge tray on which recorded recording paper is loaded, and 129 is a duct-shaped suction member disposed on the back side of the belt 6 at a portion facing the recording head 1axld, and a suction source (not shown) such as a fan is used. connected to,
Air suction is performed through the opening of the belt 6.

Reference numeral 19 denotes a control circuit that controls each part according to the control procedure shown in the second figure, for example, a CP in the form of a microcomputer.
It can be constructed using a ROM storing a program etc. corresponding to the control procedure shown in the second diagram, a working RAM, etc. 20 is a recording head 1axl under the control of a control circuit 19;
21 is a motor driver that also drives the belt drive sleeve 8, 22 is a charger driver that also drives the charger 12, and 23 is a transport motor 33 that is also connected to the transport roller 14. This is a motor driver. Further, the operations of the head 8 moving means 24 and the cap accommodating means 25 are also controlled by the control circuit 19.

FIG. 2 is an enlarged plan view of a part of the belt 6 according to this example.

Here, 61 is an opening, which has a width that allows ink ejected from a predetermined number of ejection ports to pass through, and is arranged in multiple stages at a predetermined pitch along the arrangement direction of the ejection ports of the head 1. A plurality of rows of openings are arranged at different positions in the sub-scanning direction, so that a predetermined number of rows (four rows from row A to row D in this example) can handle ink ejection from all the ejection ports. In addition, 128 is an attachment end of the presser member 12 to the belt 6, and 12B is a free end.

FIG. 3 is a flowchart showing an example of the recording processing procedure including the recovery process, FIGS. 4(A) to (0) are side views of the head unit and the vicinity of the cap in the process, and FIG. 5 is a diagram of the conveyance system near the head. These are schematic diagrams, and the operation of this example will be explained using these diagrams.

First, Fig. 4 (^) shows the power off state, and a cap 3 is attached to the orifice surface where the ejection opening of the recording head l is provided to prevent ink from evaporating from the orifice. .

From this state, when the power is turned on in step Sl in FIG.
m by the head moving means 24 (FIG. 4(B)). In this state, if a dry ejection signal is supplied, ink is ejected a predetermined number of times from all nozzles (dry ejection).
is performed (steps 55 and 57), caps 3a-3
In this example, this blank firing for d is normally performed when the power is turned on, but if recording unevenness or the like occurs, the configuration may be such that the operator can manually input a start signal by operating a button.

Next, in step S9, the cap unit is moved in the opposite direction to the X direction by the cap moving means 25, and is placed in a position where the cap fits between each head (see FIG.
)). Then, in step Sll, the head unit is lowered and set at a position where the ejection port is, for example, a distance of about 1 - from the belt surface, that is, a recording position (see Fig. 4).
D)).

After that, the belt motor 8 is turned on in step S12^, and the presence or absence of a dry ejection instruction signal is checked in step 512B. However, since the first sheet is processed immediately after the processing in step S7 is completed, the dry ejection in step 512C is performed. The process is skipped and the process goes to step 513 for eight lines. Note that the process of step 512C will be described later.

Next, in step 513, the paper feeding motor is turned on,
In response, one sheet of recording paper 27 in the cassette 26 is picked up by the paper feed roller 16, guided by the guide 13, and sandwiched between the conveyance roller 14 and the pinch roller 15. The passage of the leading edge of the recording paper 27 is detected by a photosensor or the like provided just before the registration section, and the paper feed control is turned on until the leading edge reaches the registration section (steps 513, 515). At this time, the extra recording paper is fed into a loop within the space of the chevron-shaped guide 13, and
Due to the "straightening" of the recording paper, the leading edge aligns with the registration portion, ensuring orthogonality with the conveyance direction.

At this time, for example, by setting using the photosensor 121, the presser member 12 is placed in the fifth position with respect to the rollers 11 and 9a.
It is assumed that they are positioned as shown in the figure. That is, although the belt 6 follows the curvature of the idle roller 9a, the free end side of the presser plate 12 is raised from the belt 6 against the magnetic force. When the recording paper 27 is fed in this state, its leading edge enters between the belt 6 and the presser member 12, and
It will hit the resist part. Then, with subsequent conveyance, the pinch roller 11 presses the pressing member 12 onto the belt 6.
Since the pressing member 12 is biased toward the belt 6 by magnetic force,
The leading edge of the recording paper 27 is gripped (step 516).

Next, in step 517, a suction operation by the suction member 129 is started, and the recording paper 27 is suctioned onto the belt 6 by suctioning through the opening 61. On the other hand, the feed amount of the recording paper 27 is counted in synchronization with the activation of the belt motor 8, and the leading edge of the recording paper is
From the time point d is reached, printing (recording) of each color is performed (step 521).

As shown in FIG. 5, the recording paper 27 that has been recorded is pressed against the belt 6 by the pressing member 12 at the belt drive roller rough.
When the sheet is opened without being able to accommodate the curvature along the roller rough (step 522), the sheet is separated from the belt 6 and is discharged to the sheet discharge tray 18. After the completion of paper ejection is detected in step S23, the belt motor 8 is activated in step S25.
Then, the suction operation by the suction member 129 is turned off.

Next, in step S27, it is determined whether the series of recordings has been completed.

If the next recording is not performed, the head unit is raised in step 529 (FIG. 4(C)), and the cap unit is set in step 531 (FIG. 4(B)).
)), the head unit is installed in step S33 (FIG. 3A)), and the power is turned off in step S35.

If recording is to be performed on the mature recording paper 27, the process moves to step 512^, where the belt motor 8 is turned on, and the presence or absence of a blank ejection signal is detected at step 512B. If there is a signal, in step 512G, based on the output of the photosensor 26, the through hole 6 on the belt surface is located at a position facing the head 1 according to the detected belt position.
By selectively ejecting droplets from the corresponding ejection ports toward the ejection port 1, ejection recovery processing for preventing clogging and the like is performed. In this example, as shown in Figure 2, the head 1 is arranged in four rows A to D.
The empty discharge of 3456 nozzles installed in

In Figure 2, the width of these four rows in the sub-scanning direction is 50 mm, and if the distance between the recording sheets is set to 70 mm during continuous paper feeding, it becomes possible to perform idle ejection by using the space between the recording sheets. . Then, the ejected ink is received by the suction member 129. If a filter, an absorber, or the like is provided in the suction member 129, the received ink can be appropriately collected.

After that, or if a negative determination is made in step 512B, the process advances to step 513, the paper feed motor is turned on, and the same recording sequence as for the previous sheet is repeated.

It goes without saying that the present invention is not limited to the above-mentioned configurations as long as a line-shaped recording head is used.

For example, the number of recording heads on the upper side is four in correspondence with the ink colors, but it goes without saying that the number can be any desired.

In addition, as a recovery process, ink is discharged by dry ejecting toward the cap or suction member on the upper side, but by pressurizing the inside of the print head or reducing the pressure in the gap, ink can be discharged from the ejection ports. It may also be something that discharges.

Furthermore, although the recording paper was smoothed using a suction member on the upper side, this may be achieved by, for example, placing a pinch roller for smoothing the recording paper at a position immediately in front of the head.

In addition, on the upper side, the belt is made of magnetic rubber and the presser plate is made of a magnetic material, but the presser member may also be a magnetic plate member, or a thin iron plate may be attached to the surface of the rubber belt, and recording paper may be used. The pressing member may be formed of a magnet.

In addition, it goes without saying that the number of holding members can be adjusted as appropriate, and the shape of the holding members is not limited to the upper side that presses down the entire width of the leading edge of the recording material.

[Effects of the Invention] As explained above, according to the present invention, there is provided a conveyor belt for recording material, and a plate-shaped pressing member that is fixed to the belt at one end and left free at the other part. In addition, the belt and the presser member are attracted to each other so that they are aligned along the flat part of the belt, and the magnetic force that is strong enough to lift the member from the belt is created in the curved part of the belt, so that when recording starts, the belt and the presser member Since the recording material is gripped between the head and the head, the leading end of the recording material does not get caught in the head, and a highly reliable device that does not cause problems such as paper jams can be realized.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of the configuration of the liquid jet recording apparatus of the present invention, FIG. 2 is a plan view showing an enlarged part of the conveyor belt, and FIG. 3 is an ejection recovery process using the configuration shown in FIG. 1. A flowchart showing an example of a recording processing procedure including
) is a side view for explaining the sequential movement of the recording head and cap according to this example, and FIG. 5 is a schematic diagram of the conveyance system near the head. DESCRIPTION OF SYMBOLS 1... Recording head, 2... Recording head holder, 3... Cap, 4... Ink tank, 5... Ink supply tube, 6... Belt, 7... Belt drive roller, 8... Motor, 9... Idle roller, lO... Tension roller, 11... Pinch roller, 12... Pressing member, 13... Guide, 14... Conveyance roller, 15... - Pinch roller, 16... Paper feed roller, 17... Cleaning unit, 18... Paper ejection tray, 19... Control circuit, 20... Head driver, 2I... Soter driver, 22... Charger driver, 23... Motor driver, 24... Head 8 moving means, 25... Cap moving means, 61... Opening, 121... Photo sensor, 129... Suction member. Figure 2

Claims (1)

[Scope of Claims] 1) A liquid jet recording apparatus that performs recording by ejecting a recording liquid onto a recording material, comprising: a belt member serving as a means for conveying the recording material; and a belt member on the front side in the conveyance direction. a presser member having one end fixed and the other part unfixed, and between the belt member and the presser member, where the belt is flat, the presser member is arranged along the belt. A liquid jet recording apparatus characterized in that magnetic force exists to such an extent that the belt member attracts each other and the holding member floats up at a portion where the belt member has a curvature.