JPH06246911A - Transfer medium and ink jet recording apparatus using same - Google Patents

Abstract

PURPOSE:To ensure the reliability of a head always accurately holding a printing position and a printing direction with respect to papers having various sizes in a transfer type ink jet recording apparatus. CONSTITUTION:After an ink image is formed on the surface of a transfer drum 1, the leading end of recording paper 5 collides with the recording paper leading end restricting surface 13 arranged on the transfer drum 1 and the position and direction of the recording paper are restricted. Since pressure transfer is started by pressing the part near to the leading end of the recording paper 5 of which the position and direction are restrained by a pressure roller 3, the printing position from the recording paper can be always accurately set even in recording papers having various sizes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer medium and a transfer type ink jet recording apparatus using the transfer medium.

[0002]

2. Description of the Related Art A transfer type ink jet printer has a feature that nozzle clogging due to unintentional contact between recording paper or paper dust and a recording head does not occur and high reliability is obtained. As such a transfer type inkjet printer, the configurations described in US Pat. No. 4,538,156 and US Pat. No. 5,099,256 are known.

In these apparatuses, an ink jet recording head (hereinafter referred to as a recording head) having a plurality of nozzles is provided on a cylindrical transfer medium with a gap therebetween. The transfer medium is composed of a metal tube and an elastic layer covering the metal tube. Silicone rubber or silicone rubber containing iron oxide is used as the elastic layer. These devices are configured to transfer an ink image onto a recording medium by writing an ink image on the transfer medium, by bringing a recording medium, which is a recording medium, into contact with the transfer medium and pressing it from behind.

Among these, in the construction described in US Pat. No. 4,538,156, the recording paper is supplied from a supply tray to a tray-shaped paper support for positioning the recording paper. The paper support determines the position of the recording paper by its inclination and the edge provided at the lower end. One end of the positioned recording paper protrudes from the support and is located between the transfer drum, which is the transfer medium, and the pressure roller, which is the transfer means.When the pressure roller is brought into contact with the transfer drum, the recording paper always has the same position. The transfer will start from. Meanwhile, US Pat.
In the configuration described in the specification No. 6, the recording paper is fed by a specified amount from the supply tray so that the leading end of the recording paper is always at the transfer start position. Further, in the same construction, a method is adopted in which the position of the recording paper is regulated by feeding the recording paper to the contact portion while pressing the pressure roller against the transfer drum and stopping the leading end of the contact portion.

[0005]

In an apparatus using a paper support, the size of the recording paper is defined by the paper support, and if a different size recording paper is used, another paper support must be prepared. It has drawbacks.

Further, in the apparatus for determining the position of the paper by defining the paper feed amount, when the recording paper is slanted or the paper feed is reduced due to the slip of the paper feed roller due to paper dust or the like, it is possible to determine the position. It cannot be corrected. In a device that regulates the position of the recording paper at the contact portion between the transfer drum and the pressure roller, the contact portion is wedge-shaped, and if the recording paper is inserted at an angle, the tip of the recording paper is bitten and cannot be corrected. It has drawbacks.

Due to the above-mentioned drawbacks, there are drawbacks that printing is performed obliquely on the recording paper and the printing is deviated from the recording paper.

The present invention has been made from the above viewpoint, and a transfer medium capable of always obtaining an image at a correct printing position by accurately defining the positions and orientations of recording papers of various sizes, and the transfer medium. It is to realize an ink jet recording apparatus using.

[0009]

The invention according to claim 1 is
In a transfer medium that carries an ink image composed of ink droplets ejected by a recording head on a surface and transfers it to a recording medium,
It is characterized in that a recording medium front end regulating surface is provided on a part of the outer surface of the cylindrical shape.

A transfer medium according to a second aspect of the present invention is characterized in that the recording medium front end regulation surface is constituted by a single continuous surface from end to end of the transfer medium.

A transfer medium according to a third aspect of the invention is characterized in that a plurality of recording medium front end regulating surfaces are provided on the same generatrix of the transfer medium.

A transfer medium according to a fourth aspect of the present invention is characterized in that the recording medium front end regulation surface protruding from the transfer medium can be stored in the transfer medium.

A transfer medium according to a fifth aspect is characterized in that the recording medium front end regulation surface is stored in the transfer medium by a cam mechanism.

According to a sixth aspect of the present invention, there is provided a transfer medium, wherein the recording medium front end regulating surface is stored in the transfer medium by an actuator driven by an external signal.

A transfer medium according to a seventh aspect is characterized in that a groove is formed in a part of the transfer medium to form a recording medium front end regulation surface of the recording medium.

According to another aspect of the present invention, there is provided an ink jet recording apparatus, wherein a recording head which selectively ejects ink droplets to form an ink image on the transfer medium and a transfer medium which faces the recording head and is rotatably held. And a transfer means for transferring the ink image on the transfer medium to a recording medium.

[0017]

The recording medium front end regulating surface that is substantially perpendicular to the sheet passing direction is provided on the transfer medium, and the recording sheet is supplied toward the regulation surface. When the leading edge of the recording paper hits the recording medium leading edge regulation surface, the direction of the recording sheet that is inclined is corrected and the leading edge is positioned. By causing the front end of the recording paper, the position and orientation of which have been determined, to be brought into contact with the transfer medium by the pressure roller which is the transfer means, transfer is always started from the correct position of the recording paper in the correct direction.

[0018]

EXAMPLES The transfer medium and ink jet recording apparatus according to the present invention will be described below with reference to examples.

FIG. 1 is a perspective view of an ink jet printer using the transfer medium of the first embodiment according to the present invention.

An inkjet recording head 2, a pressure roller 3 as a transfer means, and a paper guide plate 4 are sequentially arranged around a transfer drum 1 as a transfer medium. Arrow
The moving direction of each member is shown.

The recording head 2 is an ink jet recording head of the type using a piezoelectric element, and a plurality of nozzles are arranged side by side in the axial direction of the transfer drum 1 toward the transfer drum 1. The ink is supplied from the ink container 21.

The transfer drum 1 is a raw tube 1 made of aluminum.
1. A regulation member 14 made of silicone rubber having a wedge-shaped cross section is attached around the periphery of 1, and silicone rubber or the like is laminated as a surface layer 12, and a recording medium tip regulation surface 13 is formed on the surface. The surface of the rubber of the surface layer 12 is subjected to a release agent coating treatment so as to have a property of easily transferring an ink image.

The pressure roller 3 is a rubber roller formed of acrylonitrile rubber on a steel core material, and is configured to be pressed against the transfer drum 1 by a load device (not shown). In the transfer step, the recording paper 5, which is a recording medium, is pressed against the transfer drum 1 from the back side. The transfer load is about 5 in this embodiment.
To 30 kg weight.

The paper guide plate 4 is made of steel and guides the recording paper 5 supplied from a paper feeding device (not shown) between the transfer drum 1 and the pressure roller 3, so that the recording paper 5 comes into contact with the transfer drum 1 before transfer and becomes dirty. It prevents it from being lost.

The ink is an ink in which a pigment is dispersed in water, which is a solvent, together with an emulsion and a surfactant, and the water accounts for 60 to 80% of the whole and has a low viscosity. An ink that thickens by lowering the amount of water on the transfer drum was used.

Next, the operation will be described. At the start of the printing operation, the transfer drum 1 starts rotating in the direction of the arrow by a driving unit (not shown).

The recording head 2 to which ink is supplied from the ink tank 21 is transferred from the plurality of nozzles to the transfer drum 1.
Ink droplets are selectively ejected in accordance with the rotation and the print pattern, and an ink image is written on the transfer drum 1.

After the writing of the ink image is completed, the recording medium front end regulating surface 13 of the transfer drum 1 is stopped at a predetermined position as shown in the figure, and a recording paper 5 is recorded along a paper guide plate 4 from a paper feeding device (not shown). It is sent to the media leading edge regulation surface.

The recording paper 5 on the recording medium front end regulation surface 13 is pressed against the transfer drum 1 by the pressure roller 3, and the ink image on the transfer drum 1 is transferred as the transfer drum 1 rotates.

The recording paper 5 to which the ink image is transferred is separated from the transfer drum 1 by a separating device (not shown) and output.

FIG. 2 is a plan view showing the action of the recording medium front end regulating surface of the transfer drum of the first embodiment. The right end of the recording paper 5, which is obliquely supplied to the recording medium front end regulation surface 13 on the surface of the transfer drum 1 as shown by an arrow, hits the recording medium front end regulation surface 13. When the recording paper 5 is further supplied, the recording paper 5 bends because its front end is regulated. The entire leading edge contacts the recording medium leading edge regulation surface 13. If the transfer medium front end regulation surface 13 is configured to extend over the entire width of the transfer drum 1 as in the present embodiment, it is possible to perform alignment with recording paper of any size smaller than the width of the transfer drum. In the present embodiment, an example in which the recording paper is supplied in a state where the transfer drum is stopped is shown, but it is obvious that the same operation is exhibited if the recording paper supply speed is higher than the rotation speed of the transfer drum. It is possible to speed up the total printing speed or to perform high-speed continuous printing without stopping the printing.

FIG. 3 is a perspective view showing the transfer drum of the second embodiment. Three transfer medium restriction surfaces 13 are attached to the transfer drum 1 at regular intervals in a line. Separation claws for separating the transfer drum and the recording paper pass through the gap between the transfer medium front end regulation surfaces 13.

FIG. 4 is a sectional view showing the operation of the transfer drum of the second embodiment. The recording paper 5 is conveyed along with the rotation of the transfer drum 1 immediately after the start of the transfer operation. The tip of the separation claw 6 is in contact with the transfer drum 1 and enters between the transfer drum 1 and the recording paper 5 to separate them. The recording paper 5 is attached to a paper discharge means (not shown).
Induce.

According to this embodiment, the size of the recording paper that can be used is limited, but even a soft recording paper, which may follow the curvature of the transfer drum, can be reliably separated from the transfer drum, and the reliability of the paper passage is improved. You can improve your sex.
In the present embodiment, the transfer drum provided with three transfer medium front end regulation surfaces is shown, but by optimizing the number and arrangement of the transfer medium, the same paper passing reliability can be obtained for a larger size of recording paper. Obtainable.

FIG. 5 is a sectional view showing the transfer drum of the third embodiment. Two transfer medium front end regulating surfaces 13 are provided on the surface of the transfer drum 1 at exactly opposite positions. Transfer drum 1
An image for two pages is written in and the two recording papers are positioned and transferred on the transfer medium front end regulation surfaces.

According to this embodiment, it is possible to write two images, which are about half the circumference of the transfer drum, at once and transfer them to the correct positions on the recording paper. If the number of transfer medium leading edge regulating surfaces 13 is increased, it is possible to position as many recording sheets as that.

FIG. 6 is a perspective view showing the transfer drum of the fourth embodiment according to the present invention. The transfer drum 1 is provided with a stepped groove 15 as shown in FIG.
The restriction member 14 having 3 is attached to the groove 15 via the spring 16.

7 and 8 are sectional views showing the operation of the transfer drum of the fourth embodiment. FIG. 7 shows a state before transfer,
The restricting member 14 causes the recording medium front end restricting surface 13 to protrude from the surface of the transfer drum by a spring 16 at a height such that it does not hit the adjacent recording head. At the start of transfer, the metal pressure roller 3 presses the recording paper 5 and the regulating member 14 is stored in the groove 15 of the transfer drum 1 as shown in FIG.

As shown in the first to third embodiments, in the structure in which the regulating member is attached as a protrusion on the surface of the transfer drum, the regulating surface at the leading end of the recording medium interferes with the pressure roller to form a portion where the recording paper cannot be pressed, resulting in printing. Impossible areas occur. In order to reduce the unprintable area, there is a method of using a flexible rubber roller for the pressure roller and making the regulating member made of rubber, but it requires a large load and rotational torque to deform and rotate the rubber roller. . In this embodiment, since the recording medium front end regulation surface is stored at the start of transfer, the unprintable area is eliminated, printing can be performed from the front end of the recording paper, and the pressing load of the pressure roller can be reduced. The rotation torque of the transfer drum can also be reduced.

9 and 10 are front views showing the transfer drum of the fifth embodiment according to the present invention. A regulating member 14 having a recording medium front end regulating surface 13 is swingably attached to the transfer drum 1 as shown in FIG. 9, and is projected from the transfer drum by a spring 16. Links 17 are attached to both ends of the regulating member 14 and are in sliding contact with cams 18 located and fixed at both ends of the transfer drum 1. The transfer drum 1 rotates as shown in FIG.
When the position is approached, the regulating member 14 is stored in the transfer drum 1 according to the cam 18.

According to the present embodiment, the cam is adjusted so that the regulating member is stored in accordance with the movement of the regulating member to the position of the adjacent recording head, and the collision between the recording head and the regulating member is avoided. The distance between the recording head and the transfer drum can be reduced, resulting in higher-definition printing.

Further, since the protrusion amount of the recording medium front end regulation surface can be increased beyond the distance between the recording head and the transfer drum, the positioning of the paper can be ensured.

In this embodiment, the restricting member avoids only the recording head. However, when cleaning or heating of the transfer drum occurs, a cleaning roller or a heating heater is applied to the transfer drum. Must meet or be adjacent. At that time, by improving the shape of the cam, it is possible for the regulating member to avoid a member that is in contact with or adjacent to the transfer drum.

FIG. 11 is a sectional view showing the transfer drum of the sixth embodiment according to the present invention. Similar to the fifth embodiment, the regulating member 14 that can be stored in the transfer drum 1 is projected by the spring 16. The regulating member 14 is connected to the electromagnetic solenoid 19 that is an actuator that can be operated by an external signal, and the external signal is used. The regulation member 14 can be stored in the transfer drum.

According to this embodiment, the regulation member can be stored and projected at an arbitrary timing by an external signal, and the regulation member can be stored in the transfer drum except when the recording medium is positioned. Further, it does not hinder the separation of the recording paper from the transfer drum after the start of transfer.

Further, when the cap or cleaning of the recording head is required, a capping mechanism for the recording head, a cleaning blade or the like is formed on the surface of the regulating member, and the storing function of the regulating member is used in reverse so that the capping or the like is performed on the recording head. It is also possible to press against.

12 and 13 are sectional views showing a seventh embodiment of the transfer drum according to the present invention. The transfer drum 1 is provided with a groove 15 having a wedge-shaped cross section, and forms a recording medium front end regulation surface 13.

Before transfer, as shown in FIG. 12, transfer drum 1
Is in a position facing the pressure roller 3, and the pressure roller 3 is pressed and is in contact with the recording medium front end regulation surface 13.
The recording paper 5 passed along the paper guide plate 4 passes through the gap between the pressure roller 3 and the transfer drum 1, and its leading end contacts the recording medium leading end regulating surface 13 and is positioned. After positioning, the transfer drum 1 rotates as shown in FIG. 13, and the pressure roller 3 brings the recording paper 5 into contact with the transfer drum 1 to perform transfer. At this time, if the supply speed of the recording paper 5 is faster than the rotation speed of the transfer drum 1, the leading end of the recording paper does not separate from the recording medium front end regulation surface 13 and the transfer position cannot be displaced.

According to this embodiment, there is no protrusion from the surface of the transfer drum with a simple structure, the recording head can be brought close to the transfer drum, and high image quality can be obtained at an accurate position.

Although the examples of the water-based ink using water as the solvent have been described above, the present invention can be applied to all inks using a volatile component as a solvent.

Further, in the above embodiment, an example in which paper is used as the recording medium has been shown, but the present invention can be applied to any sheet-shaped recording medium using, for example, resin, cloth or metal.

Furthermore, the recording head may be of the bubble jet type which ejects ink droplets by thermal energy.

[0053]

According to the present invention, with respect to recording sheets of various sizes, the position and orientation of the recording sheet are regulated to be normal at a position near the transfer start position, so that the rollers of the sheet feeding device are slipped. Thus, even if the recording paper is skewed during the paper feeding, it is possible to secure an accurate printing position.

[Brief description of drawings]

FIG. 1 is a perspective view of an ink jet printer using a transfer drum according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the operation of the recording medium front end regulation surface of the transfer drum of the first embodiment of the invention.

FIG. 3 is a perspective view showing a transfer drum of a second embodiment according to the present invention.

FIG. 4 is a sectional view showing the operation of the transfer drum of the second embodiment according to the present invention.

FIG. 5 is a sectional view showing a transfer drum of a third embodiment according to the present invention.

FIG. 6 is a perspective view showing a transfer drum of a fourth embodiment according to the present invention.

FIG. 7 is a sectional view showing an operation of a transfer drum of a fourth embodiment according to the present invention before transfer.

FIG. 8 is a cross-sectional view showing an operation at the start of transfer of the transfer drum of the fourth embodiment according to the present invention.

FIG. 9 is a front view showing a transfer drum of a fifth embodiment according to the present invention.

FIG. 10 is a front view showing the operation of the transfer drum of the fifth embodiment according to the present invention.

FIG. 11 is a sectional view showing a transfer drum of a sixth embodiment according to the present invention.

FIG. 12 is a sectional view showing an operation before a transfer of the transfer drum of the seventh embodiment according to the present invention.

FIG. 13 is a sectional view showing an operation at the start of transfer of the transfer drum of the seventh embodiment according to the present invention.

[Explanation of symbols]

 1: Transfer drum (transfer medium) 2: Recording head 3: Pressure roller (transfer means) 5: Recording paper (recording medium) 13: Recording medium front end regulation surface 14: Regulation member 18: Cam 19: Electromagnetic solenoid (actuator)

Claims (8)

[Claims] 1. A transfer medium for carrying an ink image composed of ink droplets ejected by a recording head on a surface and transferring it to a recording medium, wherein a recording medium front end regulating surface is provided on a part of a cylindrical outer surface. A transfer medium characterized by. 2. The transfer medium according to claim 1, wherein the recording medium front end regulating surface is constituted by a single continuous surface from the end of the transfer medium. 3. The recording medium front end regulating surface is provided in plural on the same generating line of the transfer medium.
The transfer medium described. 4. The transfer medium according to claim 1, wherein the recording medium front end regulation surface protruding from the transfer medium can be stored in the transfer medium. 5. The transfer medium according to claim 4, wherein the front end regulating surface of the recording medium is stored in the transfer medium by a cam mechanism. 6. The transfer medium according to claim 4, wherein the recording medium front end regulating surface is stored in the transfer medium by an actuator driven by an external signal. 7. The transfer medium according to claim 1, wherein the recording medium front end regulating surface of the recording medium is formed by forming a groove in a part of the transfer medium. 8. A recording head which selectively ejects ink droplets to form an ink image on the transfer medium, a transfer medium which faces the recording head and is rotatably held, and ink on the transfer medium. An inkjet recording apparatus comprising: a transfer unit that transfers an image onto a recording medium.