JP2003341158A - Image recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deterioration of a conveying means or the image recording accuracy in an image recording apparatus, and to dramatically reduce the production labor and the cost. <P>SOLUTION: An image recording apparatus 1 comprises line heads 3a-3d having a plurality of ink ejecting openings 4a-4d disposed side by side along the direction perpendicular to the medium to be recorded P conveying direction, disposed above the medium to be recorded P conveying path, and columnar platen members 10a-10d elongating in the direction perpendicular to the medium to be recorded p conveying direction, disposed at a position facing the line heads 3a-3d. The platen member 10a comprises a medium to be recorded supporting surface 11a for supporting a recording paper P being conveyed, and an ink absorbing surface 12a for receiving and absorbing an ink preliminarily ejected from each of the ink ejecting opening 4a. The platen member 10a is rotatable around the rotation axis Ca elongating in the direction perpendicular to the medium to be recorded p conveying direction. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus, and more particularly to an image recording apparatus for recording a predetermined image by ejecting ink from a plurality of ink ejection openings provided on a line head onto a recording medium. .

[0002]

2. Description of the Related Art Conventionally, based on predetermined image information,
An image recording apparatus has been proposed which records a predetermined image (including characters and symbols) on a recording medium such as paper or a thin plastic plate. In recent years, a long line head having an ink ejection port formed over the entire width of a recording region of a recording medium is provided, and ink is ejected from the ink ejection port to the recording medium conveyed in a predetermined direction by a conveying unit. An image recording apparatus (inkjet printer) that records a predetermined image by using the above has been proposed and put into practical use.

In such an image recording apparatus (inkjet printer), when left for a long time, the ink remaining in the ink ejection port of the line head dries and hardens, and clogging occurs to deteriorate the ink ejection characteristics. There is. Therefore, in order to maintain the ink ejection characteristics, so-called preliminary ejection may be performed during non-recording.

Such preliminary ejection is often performed on a conveyor belt which is a means for conveying the recording medium, and the ink ejected on the conveyor belt is a roller cleaner or a blade cleaner installed on the downstream side of the conveyor belt. It was wiped off by a belt cleaning member such as. In recent years, as described in Japanese Patent Laid-Open No. 2000-127362, a method has been proposed in which a belt cleaning member is provided in the vicinity of the downstream of each ink ejection port to quickly wipe off the ink adhering to the conveyor belt. There is.

[0005]

However, if the method of performing the preliminary ejection on the conveyor belt and wiping off the ink adhering to the conveyor belt with the belt cleaning member as described above, the ink on the conveyor belt is sufficiently wiped. It may remain without being taken. When the surface of the conveyor belt is contaminated due to the residual ink, the conveyor belt itself is deteriorated, and the transfer speed of the conveyor belt is erroneously detected, resulting in inaccurate speed control, which may reduce image recording accuracy. It was In addition, the ink remaining on the conveyor belt may be transferred to the back surface of the next recording medium, and the recording medium may be contaminated.

Further, as described above, when the method of performing the preliminary discharge on the conveyor belt and wiping the ink adhering to the conveyor belt with the belt cleaning member is adopted, a complicated mechanism or control means for driving the belt cleaning member is required. It was necessary, and it took time and cost to manufacture the device.

An object of the present invention is to provide an image recording apparatus,
This is to prevent the deterioration of the conveying means and the deterioration of the image recording accuracy, and to significantly reduce the labor and cost in manufacturing.

[0008]

In order to solve the above-mentioned problems, the invention according to claim 1 has a plurality of ink ejection ports arranged in parallel along a direction perpendicular to the conveying direction of the recording medium. A line head arranged above the conveying path of the recording medium, and a platen member which is a columnar body extending in a direction perpendicular to the conveying direction of the recording medium and which is arranged at a position facing the line head. In the image recording apparatus, the platen member includes a recording medium supporting surface that supports the recording medium that is conveyed, and an ink absorbing surface that receives and absorbs ink that is preliminarily ejected from each of the ink ejection ports. And is rotatable about a rotation shaft extending in a direction perpendicular to the transport direction of the recording medium.

According to the first aspect of the invention, the platen member is an ink which receives and absorbs the ink preliminarily ejected from each of the recording medium support surface for supporting the recording medium conveyed and the ink ejection port. The ink absorption surface of the platen member is configured to be rotatable about a rotation axis extending in a direction perpendicular to the transport direction of the recording medium. Can be confronted with. Therefore, the ink preliminarily ejected from each ink ejection port can be received and absorbed by the ink absorbing surface.

Therefore, it is not necessary to perform the preliminary ejection on the conveyor belt which is the conveyor as in the conventional case, so that the deterioration of the conveyor belt and the deterioration of the image recording accuracy can be prevented.
In addition, since it is not necessary to provide a belt cleaning member for wiping off the ink adhering to the conveyor belt at the time of preliminary ejection, the labor and cost for manufacturing the device can be significantly reduced.

According to a second aspect of the present invention, in the image recording apparatus according to the first aspect, the platen member has the recording medium supporting surface facing the line head while the recording medium is being conveyed, and preliminary ejection. The rotating position of the ink absorption surface is controlled so that the ink absorption surface faces the ink ejection port.

According to the second aspect of the present invention, the platen member can reliably support the recording medium to be conveyed by the recording medium supporting surface when the recording medium is conveyed, and at the time of preliminary ejection. In the above, the ink ejected from each ink ejection port can be reliably received and absorbed by the ink absorbing surface.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

[First Embodiment] An image recording apparatus exemplified in the present embodiment is provided with a long line head in which an ink ejection port is formed over the entire width of a recording region of a recording medium. It is an inkjet printer that discharges ink from a discharge outlet onto a recording medium to record a predetermined image.

First, the mechanical structure of the ink jet printer according to this embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic side view showing a main part of the inkjet printer according to the present embodiment.
FIG. 3 is an enlarged perspective view of the vicinity of a platen member 10a included in the inkjet printer 1.

As shown in FIG. 1, the ink jet printer 1 includes conveyance rollers 2a and 2b, which are conveyance means for conveying a recording paper (recording medium) P in a predetermined direction, and a spur 2.
c, line heads 3a to 3d arranged above the conveyed recording paper P, platen members 10a to 10d arranged at positions facing the line heads 3a to 3d and supporting the recording paper P from below, and the like. I have it.

The transport rollers 2a and 2b have a function of transporting the recording paper P in the direction of the arrow Y in FIG. 1, and are driven by a transport motor (not shown) directly connected to the shaft of the transport roller 2b. ing. By rotating the conveying roller 2b by the conveying motor, the recording sheet P is sandwiched between the conveying rollers 2a and 2b, and the recording sheet P is held in FIG.
It can be conveyed at a constant speed in the direction of arrow Y.

Recording paper detecting means for detecting the recording paper P being conveyed is provided near the conveying rollers 2a, 2b. The signal detected by the recording paper detection means is transmitted to the CPU 50 described later and used in the recording paper detection step S2 described later.

The spur 2c is a transport means arranged downstream of the transport path of the recording paper P, and is the ink discharge ports 4a to 4d.
Recording paper P on which an image is formed by ejecting ink from the recording paper P
The recording paper P is conveyed with a small contact area so as not to stain the surface of the recording paper P.

The line heads 3a to 3d are long casings slightly longer than the entire width of the recording area of the recording paper P.
A plurality of ink ejection ports 4a to 4 are arranged in parallel along a direction perpendicular to the conveying direction of the recording paper P (direction of arrow Y in FIG. 1).
have d. The line heads 3a to 3d eject ink from the ink ejection ports 4a to 4d onto the recording paper P to record a predetermined image. From the ink ejection ports 4a to 4d, yellow, magenta, and cyan, respectively. Ink of each color of black is ejected. In addition, the "line head" in the present invention includes a relatively long divided head in which a plurality of divided heads are joined together to form a long length.

Further, an ink tank is connected to the ink discharge ports 4a to 4d of the line heads 3a to 3d via an ink tube not shown, and the ink tubes are connected to the insides of the line heads 3a to 3d. An ink flow path (not shown) that communicates is provided. Further, in the vicinity of the ink discharge ports 4a to 4d of the line head, a not-shown residual ink detecting means for detecting the residual state of the ink in the ink discharge ports 4a to 4d is provided. The signal detected by the residual ink detecting means is transmitted to the CPU 50, which will be described later, and used in the preliminary ejection necessity determination step S4, which will be described later.

The platen members 10a to 10d are made of recording paper P.
1 is a long columnar body extending in a direction perpendicular to the conveyance direction of the recording paper P and is arranged at a position facing the line heads 3a to 3d, and conveys the recording paper P from below. Fulfills the function of supporting. In addition, the platen member 10
The a to 10d also function as means for receiving the ink droplets 5a to 5d during the preliminary ejection of the line heads 3a to 3d. In FIG. 1, the platen member 10a
10A to 10d are shown with the recording paper support surfaces facing the line heads 3a to 3d.

The platen members 10a to 10d are rotated about their central axes Ca to Cd by a platen rotating means (not shown).
It is supposed to be rotatable around. The platen rotating means is
Conventionally adopted mechanism, for example, platen member 1
It can be constituted by ball bearings, gears, motors, etc. provided at both ends in the length direction of 0a to 10d. Further, the platen members 10a to 10d are provided with a rotational position detecting means (not shown) for detecting the rotational position thereof. A signal relating to the rotational position of the platen members 10a to 10d detected by the rotational position detecting means is transmitted to the CPU 50 described later, and the preliminary ejection step S5 described later.
Used in.

FIG. 2 is an enlarged view of the vicinity of the platen member 10a. Since the platen members 10a to 10d have substantially the same configuration, the configuration will be described below with reference to FIG. Note that in FIG. 2, the platen member 10
The state where the ink absorption surface of a is directed to the line head 3a side is shown.

As shown in FIG. 2, the platen member 10a extends in a direction (direction of arrow X in FIG. 2) perpendicular to the conveying direction of the recording paper P (direction of arrow Y in FIGS. 1 and 2). It is a long columnar body. The platen member 10a includes a recording paper supporting surface (recording medium supporting surface) 11a and an ink absorbing surface 12a.
And have.

The recording paper supporting surface 11a is an outer peripheral surface of a cylindrical body and serves to support the recording paper P being conveyed from below. The ink absorbing surface 12a is formed by embedding a long rectangular parallelepiped-shaped ink absorbing agent 20a in a recess 13a provided in the cylindrical body and extending in the lengthwise direction. It fulfills the function of receiving and absorbing the ink that is preliminarily ejected from. Ink absorption surface 1
The width of the line 2a is larger than the diameter of the ink ejection port 4a of the line head 3a. As the ink absorbent 20a, water-absorbing open-cell foam, non-woven fabric, felt, or the like can be used. Ink absorbent 2
The ink absorbed by 0a is diffused into the atmosphere by drying with time.

Next, the electrical configuration of the ink jet printer 1 according to this embodiment will be described with reference to FIG. FIG. 3 is a block diagram for explaining the electrical configuration of the inkjet printer 1.

The ink jet printer 1 according to the present embodiment has a CPU 30 and an input device 4 as shown in FIG.
0, the conveyance roller 2b, the line heads 3a to 3d, the platen members 10a to 10d, and the like.

The CPU 30 is a control means mounted on a predetermined control board and has a function of integrally controlling the entire ink jet printer 1. The input device 40 is the CPU 30 via an input interface (not shown).
Is connected to the CPU 30 and inputs a signal relating to predetermined image information to the CPU 30. Examples of the input device 40 include a personal computer connected via a network, an image reading device that reads various images, and the like.

The carrying roller 2b is connected to the CPU 30 via an output interface and a carrying motor (not shown).
The recording paper P is conveyed in a predetermined direction (direction of arrow Y in FIGS. 1 and 2) at a predetermined speed under the control of the CPU 30. The line heads 3a to 3d are connected to the CPU 30 via an output interface (not shown).
And the ink ejection port 4a under the control of the CPU 30.
4d to discharge a predetermined amount of ink of a predetermined color to record a predetermined image on the recording paper P. Platen member 10
a to 10d are connected to the CPU 30 via an output interface (not shown) or a platen rotating means, and C
The rotational position of the PU 30 can be freely changed under the control of the PU 30.

Next, the control operation of the ink jet printer 1 according to this embodiment will be described with reference to FIGS. 4 and 5. In the following description, the “preliminary ejection operation” is intended to maintain the ink ejection characteristics by preventing the ink remaining in the ink ejection openings of the line head from drying and hardening, and to maintain the ink ejection characteristics during non-recording. It means the operation of ejecting a small amount of ink from the.

FIG. 4 (a) shows the rotation posture of the platen member 10a when the recording paper is conveyed.
(B) shows the rotational posture of the platen member 10a during preliminary ejection. Further, FIG. 5 is a flowchart for explaining the control operation of the inkjet printer 1 according to the present embodiment.

First, the conveyance motor is driven by the control of the CPU 30 to rotate the conveyance roller 2b, and the recording paper P is
The sheet is conveyed in the direction of arrow Y in FIG. 4 while being sandwiched by the conveying rollers 2a and 2b (recording sheet conveying step: S1). Next, the CPU 30 detects the conveyed recording paper P by the recording paper detection means and determines whether or not the recording paper P has been conveyed to a predetermined position (recording paper detection step: S
2).

When it is determined in the recording paper detection step S2 that the recording paper P has been conveyed to a predetermined position, C
The PU 30 drives the platen rotating means to rotate the platen member 10a, and arranges the recording paper support surface 11a so as to face the ink ejection port 4a (platen rotating step: S3, see FIG. 4A). , Performs a predetermined image recording operation. afterwards,
The control operation ends.

On the other hand, when it is determined in the recording paper detection step S2 that the recording paper P has not been conveyed to the predetermined position, the CPU 30 detects it by the residual ink detecting means of the ink ejection port 4a of the line head 3a. Based on the state of the residual ink thus formed, it is determined whether or not the preliminary ejection operation is necessary (preliminary ejection necessity determination step: S4).

When it is determined in the preliminary ejection necessity determination step S4 that the preliminary ejection operation is necessary, the CPU 30
Drives the platen rotating means to rotate the platen member 10a, and arranges the ink absorbing surface 12a of the platen member 10a so as to face the ink discharge port 4a (see FIG. 4B), and the preliminary discharge operation is performed. Perform (preliminary ejection step: S5). Then, the control operation ends. Preliminary ejection necessity determination step S4
When it is determined that the preliminary ejection operation is not necessary in step 3, the control operation is ended as it is.

In the ink jet printer 1 according to this embodiment, the platen members 10a (-10d) are
A recording paper support surface 11a for supporting the conveyed recording paper P,
Ink droplets 5 preliminarily ejected from each of the ink ejection ports 4a
The ink absorbing surface 12a that receives and absorbs a, and is rotatable about the central axis Ca. Therefore, the ink absorbing surface 1 of the platen member 10a can be rotated during the preliminary ejection.
2a can be opposed to the ink ejection port 4a (see FIG. 4B). Therefore, the ink droplet 5a preliminarily ejected from the ink ejection port 4a can be received and absorbed by the ink absorbing surface 12a.

Therefore, it is not necessary to carry out preliminary discharge on the conveyor belt as in the conventional case, so that deterioration of the conveyor belt and deterioration of image recording accuracy can be prevented. In addition, since it is not necessary to provide a belt cleaning member for wiping off the ink adhering to the conveyor belt at the time of preliminary ejection, the labor and cost for manufacturing the device can be significantly reduced.

In the ink jet printer 1 according to this embodiment, the platen member 10a (-10
In d), the CPU 30 rotates the recording paper support surface 11a so that the recording paper support surface 11a faces the line head 3a while the recording paper P is being conveyed, and the ink absorption surface 12a faces the ink ejection port 4a during preliminary ejection. Since the position is controlled, when the recording paper P is being conveyed, the platen member 10
The recording paper P to be conveyed can be reliably supported by the recording paper support surface 11a of a (~ 10d) (FIG. 4 (a)).
), At the time of preliminary discharge, the platen member 10a
The (-10d) ink absorption surface 12a can reliably receive and absorb the ink droplet 5a ejected from the ink ejection port 4a (see FIG. 4B).

In the above embodiment, the long cylindrical platen member 10a (-10d) is adopted, but the shape is not necessarily limited to this. That is, the platen member may be a columnar body extending in a direction perpendicular to the recording medium conveyance direction and having a recording medium supporting surface and an ink absorbing surface, and may be, for example, a quadrangular prism shape or a triangular prism shape. Alternatively, a hexagonal columnar platen member may be used.

[0041]

According to the first aspect of the invention, the platen member absorbs ink preliminarily ejected from each of the ink ejection port and the recording medium support surface which supports the recording medium conveyed. And an ink absorbing surface to
Since it is rotatable about a rotation shaft extending in a direction perpendicular to the recording medium conveyance direction, the ink absorbing surface of the platen member can face the ink discharge port during preliminary discharge. Therefore, the ink preliminarily ejected from each ink ejection port can be received and absorbed by the ink absorbing surface.

Therefore, it is not necessary to perform the preliminary ejection on the conveyor belt which is the conveyor as in the conventional case, so that the deterioration of the conveyor belt and the deterioration of the image recording accuracy can be prevented.
In addition, since it is not necessary to provide a belt cleaning member for wiping off the ink adhering to the conveyor belt at the time of preliminary ejection, the labor and cost for manufacturing the device can be significantly reduced.

According to the second aspect of the present invention, the platen member can reliably support the recording medium to be conveyed by the recording medium supporting surface when the recording medium is conveyed, and at the time of preliminary ejection. In the above, the ink ejected from each ink ejection port can be reliably received and absorbed by the ink absorbing surface.

[Brief description of drawings]

FIG. 1 is a schematic side view showing a main part of an inkjet printer according to a first embodiment of the present invention.

FIG. 2 is an enlarged perspective view of the vicinity of a platen member included in the inkjet printer shown in FIG.

FIG. 3 is a block diagram for explaining an electrical configuration of the inkjet printer shown in FIG.

4A and 4B are views for explaining a control operation of the inkjet printer shown in FIG. 1, in which FIG. 4A is an explanatory view showing a rotating posture of a platen member during conveyance of recording paper;
(B) is an explanatory view showing a rotation posture of the platen member at the time of preliminary discharge.

5 is a flowchart for explaining a control operation of the inkjet printer shown in FIG.

[Explanation of symbols]

1 inkjet printer 2a, 2b Transport rollers 2c spur 3a-3d line head 4a to 4d ink ejection port 5a-5d ink drops 10a to 10d Platen member 11a Recording paper support surface 12a ink absorbing surface 13a recess 20a ink absorber 30 CPU 40 input device S1 Recording paper conveyance process S2 Recording paper detection process S3 Platen rotation process S4 Preliminary ejection necessity determination process S5 preliminary discharge process

Continued front page    F term (reference) 2C056 EA24 EA27 EC12 EC24 EC54                       FA13 HA29 JC10 JC15                 2C058 AB03 AB15 AC07 AC12 AD01                       AE09 AE13 AF31 DA10 DA38

Claims (2)

[Claims] 1. A line head having a plurality of ink discharge ports arranged in parallel along a direction perpendicular to the recording medium conveyance direction, the line head being disposed above the recording medium conveyance path, and the recording medium. An image recording apparatus including a platen member extending in a direction perpendicular to the transport direction of the platen and disposed at a position facing the line head, wherein the platen member is the transported recording medium. A recording medium supporting surface for supporting the recording medium, and an ink absorbing surface for absorbing and absorbing ink preliminarily ejected from each of the ink ejection ports, and extending in a direction perpendicular to the conveying direction of the recording medium. An image recording device, wherein the image recording device is rotatable about a rotating shaft. 2. The platen member is configured such that the recording medium support surface faces the line head when the recording medium is conveyed, and the ink absorbing surface faces the ink ejection port during preliminary ejection. The image recording apparatus according to claim 1, wherein the rotation position is controlled.