JP2503857B2 - Ink jet recording device - Google Patents

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, and more particularly to a sheet feeding mechanism for recording sheets of cut sheets.

[0002]

2. Description of the Related Art Conventionally, an ink jet recording apparatus has used a belt or the like as a paper feeding means so that it can be used with various recording papers such as paper and plastic sheets. Electrostatic adsorption by a belt and air adsorption have been proposed to improve the feeding state of recording paper.

For example, in Japanese Unexamined Patent Publication (Kokai) No. 3-155947, a belt and an electrostatic adsorption mechanism for the belt are used as a feeding means for moving a recording sheet such as a cut sheet. Further, by using the leading edge curl generating means that gives a habit to face the belt side facing the recording head before the leading edge of the cut sheet reaches the recording head, the leading edge of the cut sheet hits the leading edge of the recording head and the nozzles of the head become dirty. Are prevented. As the tip curl generating means, a means for pressing the cut sheet by the roller or the belt to the roller provided inside the belt via the belt is used, and the means for pressing the cut sheet is a means for injecting an electric charge into the cut sheet. Also serve. As a result, curling can be applied while electrostatically adsorbing, and necessary and sufficient adsorption can be realized.

Further, in order to obtain good print quality, the distance between the ink jet recording head and the recording paper is set small, usually about 1 mm.

[0005]

In this conventional ink jet recording apparatus, a charger and a charger driver are required for performing electrostatic attraction, so that the apparatus configuration becomes complicated and the cost tends to increase.

Further, there is a problem in that the recording sheet floats near the ink jet recording head during printing, cockling of the printing surface, and splashing of the lower end of the recording sheet cause stains due to contact between the nozzle plate and the sheet.

Further, depending on the periphery of the recording paper, curling may occur more than necessary due to the familiarity with the ink, and a problem may occur in that the paper feed may be defective, or in the worst case, a paper jam may occur.

[0008]

The ink jet recording apparatus of the present invention comprises an ink ejecting portion of an ink jet recording head.
Platen placed on the recording area of the ink ejected from
And recording on the recording part of the ink ejected from the ink ejection part
The main feed roller that conveys the paper and the main feed
It faces the roller peripheral surface of the drive roller, and
A paper guide located upstream of the recording paper transport direction
Between the paper and the peripheral surface of the main feed roller and the paper guide.
Fixed to the paper guide and the means to feed the recording paper into the
Between the peripheral surface of the main feed roller and the paper guide
Surface of the recording paper conveyed from the ink to the ink ejection unit
Hold the paper to the platen side
Make sure that the hold-down sheet covers the front of the ink ejection unit.
Means for rotating the blade along the peripheral surface of the main feed roller .

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a side view showing an embodiment of the present invention, and FIG.
2 is a perspective view of the embodiment of FIG. 1. FIG. However, FIG. 2 shows only a main part of FIG. 1 in a perspective view.

In the drawing, a recording sheet (cut sheet) 1
3 is fed onto the guide plate 23 by the feed rollers 21 and 22, and is inserted from below between the cylindrical main feed roller 9 and the semi-cylindrical movable paper guide 4. A paper feed roller 5 is arranged below the movable paper guide 4, is in contact with the main feed roller 9, and is rotated by the rotation of the main feed roller 9. As a result, the recording paper sent from the guide plate 23 is sent while being sandwiched between the main feed roller 9 and the paper feed roller 5, passes through the inside of the movable paper guide 4, and then reaches the flat platen 10 for inkjet recording. It is recorded by the head 1.
After recording, the paper is discharged by the discharge roller 11 and the spur roller 912.

A main feed roller gear 8 is fixed coaxially with the main feed roller 9, and the gear 8 rotates together with the main feed roller 9. When the main feed roller gear 8 is a roller for rotating the main feed roller 9, a driving force from a motor (not shown) is transmitted to the main feed roller gear 8 via a power transmission gear (not shown). The main feed roller gear 8 may be integrated with the main feed roller 9 without a shaft.

The main feed roller gear 8 can mesh with the internal teeth of a sheet rotation slide internal gear (hereinafter abbreviated as slide internal gear) 6 that is movable along the axis of the main feed roller 9. As will be described later, the slide internal gear 6 is pulled toward the side frame 100 side by the tension spring 15 when the electromagnetic clutch 7 is not operating, and is separated from the main feed roller gear 8 to cause the electromagnetic clutch 7 to move.
Is moved to a position where it meshes with the gear 8.

As shown in FIG. 2, when the slide internal gear 6 meshes with the main feed roller gear 8, the movable paper guide 4 is connected to the slide internal gear 6 via the arm portion 6a and the Power will be transmitted. The arm portion 6a is sandwiched between the two protrusions 4a and 4b and coupled. The clearance between the arm portion 6a and the protrusions 4a and 4b is about 0.5 mm.

The movable paper guide 4 is provided with a slide internal gear 6 in order to move the position of the sheet-like elastic paper retainer sheet 2 fixed to the upper part of the movable paper guide 4 from the blackened position in FIG. It is connected and rotates slightly.

The sheet presser sheet 2 is installed at a position (initial position) where the upper end of the sheet is 2 to 3 mm below the printing area when the movable sheet guide 4 is not yet moved. During printing, the paper holding sheet 2 is at its initial position to prevent the recording paper 13 from floating. The sheet 2 is made of polyester having a thickness of 0.5 mm or less.

Two sheet detection sensors 3 are fixed to the outside of the movable sheet guide 4. A notch 4c is provided corresponding to the position of the sensor 3.

FIG. 3 is a block diagram of an electric system of the ink jet recording apparatus of the present invention, and FIG. 4 is a flow chart showing its operation.

In FIG. 3, the recording signal 33 is the control circuit 3
It enters 0 and is applied as a print signal to the inkjet recording head 1. The control circuit 30 connects the paper detection sensor 3 and the electromagnetic clutch 7, and controls each part based on the flowchart of FIG. The control signal 32 is an electric signal for moving the roller and the like, but the method of driving the roller is omitted.

Next, the operation of the embodiment of the present invention will be described with reference to the flowchart of FIG. 4 and FIGS.

When the power is turned on, the ink jet recording head 1 returns to the home position and the nozzle plate 14
Is protected there by wiping capping etc. Then, the presence or absence of the recording paper 13 (step (1)) is detected by the paper detection sensor 3, and if the recording paper is not left in the middle of the movable paper guide 4 and the sensor is OFF,
Then, the paper feeding operation is started (step (2)). In the paper feeding operation, the paper is fed along the movable paper guide 4 by the paper feed roller 5 and the main feed roller 9.

When the upper end of the recording paper 13 is detected by the paper detection sensor 3 (step (3)), a line feed is performed from there to several steps of paper setting position (step (4)).
A line feed motor (not shown) for rotating the main feed roller 9 uses a step motor and has a specification capable of fine line feed. Then, the printing operation (steps (5) and (6)) is started, but during printing, the recording sheet 13 prevents the recording sheet 13 from floating and does not come into contact with the nozzle plate 14.

When the lower end of the recording paper 13 of the paper detection sensor 3 is detected (step (7)), a line feed is performed for several steps to a position where the lower end is the paper holding sheet 2 and is firmly held (step (10)). Here, the electromagnetic clutch 7 is turned on (step (11)), the slide cam 70 is sucked by the electromagnetic clutch 7, and the slide internal gear 6 is pushed out to the main field roller gear 8 side. As a result, the internal slide gear 6 meshes with the main feed roller gear 8. In this state, the movable paper guide 4 rotates slightly together with the attached paper retainer sheet 2 in conjunction with the ejection operation by the main feed roller 9, paper ejection roller 11, and spur roller 12 (step (1
2)). The rotational displacement is the range that covers the nozzle plate 14 as shown by the wavy line position in FIG.

In this way, the discharge operation can be performed on the nozzle plate 14 while the lower end of the recording paper 13 is held by the paper retainer sheet 2. Therefore, the contact of the lower end of the paper with the nozzle plate 14 due to the flipping up is prevented. it can. After a slight rotational displacement up to the nozzle plate 14, the electromagnetic clutch 7 is turned off (step (13)), the slide cam 70 is moved in the direction opposite to the electromagnetic clutch 70 by a tension spring (not shown), and the slide internal gear 6 is moved. Is tension spring 15
Slides and is disengaged from the mesh with the main feed roller gear 8. In this state, the paper discharge operation is continued,
After the completion of paper discharge (step (14)), the electromagnetic clutch 7 is turned on again (step (15)), and this time the movable paper guide 4 is rotated in the reverse direction to return to the original state (step (16)). . Thereafter, the electromagnetic clutch 7 is turned off (step (17)), and all the operations are completed.

As another movable means, a planetary gear 18 as shown in FIG. 5 can be considered. (However, the unevenness of each gear is omitted in FIG. 5.) The planetary gear 18 is a slide type like the internal slide gear 6, and slides by the electromagnetic clutch 7. However, in the case of FIG.
The electromagnetic clutch 7 may be arranged parallel to the main feed roller shaft and may be slid without using a slide cam. Paper guide movable arm 17 interlocking with the movable paper guide 4
Is controlled by the arm angle control circuit 19 to be slightly rotated. The paper guide movable arm 17 is fixed to the planet gear 18 and slides on the shaft of the main feed roller gear 8. Step (1) in FIG.
In 2) and (16), the arm 17 is rotated in the forward or reverse direction by the operation of the arm angle control circuit 19.

Further, the ink jet recording apparatus of the present invention is
The recording unit is applicable not only to the electrothermal conversion system using a heater, but also to the electromechanical conversion system using a piezoelectric element.

[0027]

As described above, according to the present invention, the movable sheet guide and the sheet-holding sheet of the sheet-like elastic material attached thereto are installed at the position where the upper end of the sheet is slightly lower than the printing area to perform printing. The floating inside is prevented, and furthermore, the lower end of the recording paper can be ejected on the nozzle plate while being held by the paper retainer sheet, so it is possible to prevent contact stains with the nozzle plate due to splashing of the lower end of the recording paper. , With good paper feed and high print quality.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a perspective view of a main part of an embodiment of the present invention.

FIG. 3 is a block diagram of an electric system according to an embodiment of the present invention.

FIG. 4 is an operation flowchart of the present invention.

FIG. 5 is a side view of a sheet movable guide means using a planetary gear.

[Explanation of symbols]

 1 Inkjet recording head 2 Paper holding sheet 3 Paper detection sensor 4 Movable paper guide 5 Paper feed roller 6 Paper guide rotation slide internal gear 7 Electromagnetic clutch 8 Main feed roller gear 9 Main feed roller 10 Flat platen 11 Paper ejection roller 12 Spurs Roller 13 Recording paper (cut paper) 14 Nozzle plate 15 Tension spring 16 Arm stopper 17 Paper guide movable arm 18 Planetary gear 19 Arm angle control circuit

Claims (4)

(57) [Claims] 1. An ink jet recording head ejects ink.
In an ink jet recording apparatus that ejects ink from a recording section to record on a recording sheet , the recording section is arranged on the recording section of the ink ejected from the ink ejecting section.
The platen and the recording portion of the ink ejected from the ink ejection unit
A main feed roller that conveys a recording sheet and a roller peripheral surface of the main feed roller that face the main feed roller.
Upstream from the ink ejection unit in the transport direction of the recording paper
Of the paper guide positioned at the outer peripheral surface of the main feed roller and the paper guide.
A means for feeding the recording paper in between, and a main feed roller fixed to the paper guide.
Between the peripheral surface of the paper and the paper guide,
The surface of the recording paper conveyed toward the platen side.
And a sheet for holding down the sheet, and the sheet for holding the sheet covers the front of the ink ejection unit.
So that the paper guide fits around the main feed roller.
An inkjet recording head including means for rotating along . 2. The ink jet recording apparatus according to claim 1, wherein the paper guide is a movable paper guide that slightly rotates in conjunction with a discharging operation. 3. The ink jet recording apparatus according to claim 2, wherein the movable means of the movable paper guide is an electromagnetic clutch and a slide internal gear for rotating the paper guide. 4. The ink jet recording apparatus according to claim 2, wherein the movable means of the movable paper guide is an electromagnetic clutch and a planetary gear.