JP2001353863A - Image output unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet printer comprising a mechanism for carrying a recording sheet along a carrying face, a first ink ejection unit for ejecting ink to the surface side of a recording sheet being carried by the carrying mechanism, and a second ejection unit for ejecting ink to the rear surface side of the recording sheet being carried by the carrying mechanism wherein both the surface and the rear surface of an independent sheet-like recording sheet can be recorded individually. SOLUTION: A section 20 for fixing ink ejected from a first ink ejection unit 12 and ink ejected from a second ink ejection unit 14 is disposed on the downstream side of the first and second ejection units 12, 14 with regard to the carrying direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image output apparatus, and more specifically, to a transport mechanism for transporting a recording material along a transport surface, and an ink on a front side of the recording material transported by the transport mechanism. The present invention relates to an image output apparatus including a first ink ejection unit for ejecting ink and a second ejection unit for ejecting ink to the back side of the recording material conveyed by the conveyance mechanism.

[0002]

2. Description of the Related Art Such an image output apparatus is disclosed in Japanese Patent Application Laid-Open No. Hei 8-216467 or Japanese Patent Application Laid-Open No. 9-2400.
A technique described in Japanese Patent Publication No. 68 is known.

[0003] In the image output device according to the above-mentioned known technique,
Rotary paper is used as a recording material, and the rotary paper printed on the front side by the first printing unit is reversed in the running direction by the reversing device after passing through the drying unit, and is then printed on the back side by the second printing unit. Printing is performed, and by passing through the drying unit again, double-sided printing is completed.

[0004]

However, the recording material that can be used in the image output apparatus according to the above-mentioned known technique is a long rotary paper and a thin rigid sheet because it needs to be smoothly inverted by an inverting apparatus. It was limited to recording materials. Further, the configuration in which the drying unit is dried for each print has been an obstacle to downsizing the image output device.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image output apparatus capable of recording on both front and back sides of an independent sheet-like recording material in view of the above-mentioned drawbacks of the above-mentioned prior art image output apparatus. Is to do. Another object of the present invention is to provide an image output apparatus capable of recording on both front and back surfaces of a recording material having relatively high rigidity. Still another object of the present invention is to provide a smaller-sized image output device.

[0006]

To achieve the above object, an image output apparatus according to the present invention has the features described in the first to seventh aspects of the present invention. That is, the image output device according to claim 1 of the present invention further includes a fixing unit that fixes the ink ejected by the first ink ejection unit and the ink ejected by the second ink ejection unit. , With respect to the direction of conveyance, the first discharge unit and the second discharge unit are disposed downstream.

[0007] In order to have such a characteristic configuration,
In the image output device according to the first aspect of the present invention, both the ink ejected to the front side of the recording material by the first ejection unit and the ink ejected to the back side of the recording material by the second ejection unit are used. A configuration in which a fixing process is performed simultaneously by a fixing unit located downstream of the unit can be realized. Therefore, it is not necessary to fix the ink adhered to the front side by the first ejection unit before the same portion of the recording material reaches the second ejection unit. A reversing mechanism is not required, and for the same reason, it is not necessary to use a long rotary paper, and conversely, it is possible to employ a recording material in the form of an independent sheet. Further, since the recording material does not pass through the mechanism for reversing the recording material, it is possible to employ a recording material having relatively high rigidity (such as a normal postcard). Further, since a reversing mechanism of the recording material is not required, a more miniaturized image output device can be easily provided.

More specifically, the first ejection unit includes an ejection head capable of forming a photographic image on a recording material by ejecting at least CMY inks, and the second ejection unit includes a character or graphic. And a discharge head that can be formed on a recording material.

[0009] With this configuration, an image such as a photographic image or an illustration is printed in color on the front side and characters or figures are printed on the back side. Can be provided.

[0010] More specifically, the transport mechanism has an endless belt wound around at least a pair of rotating rollers, and the first ink discharge unit faces a recording material mounting surface of the endless belt. The fixing unit is disposed downstream of the endless belt, and the second ink ejection unit is disposed between the endless belt and the fixing unit. Good.

[0011] More specifically, a guide member capable of supporting the recording material is provided between the endless belt and the fixing unit, and the guide member transfers the recording material.
The image forming apparatus may further include a support surface that supports the ink via the outside of the recording area where the ink is ejected by the second ink ejection unit.

That is, when a recording material having a certain degree of rigidity such as ordinary postcards is used, ink is ejected by the second ink ejection unit to a short range between the endless belt and the fixing section. The ink ejected from the second ink ejection unit is provided only by providing a support surface that supports the portion via the outside portion (for example, two locations along the longitudinal direction of the second ink ejection unit) of the recorded recording area. It is possible to constitute a supporting means having a shape sufficient to receive the ink and having no fear of contaminating the unfixed ink discharged from the second ink discharging unit.

[0013] Alternatively, more specifically, a guide member capable of supporting the recording material is provided between the endless belt and the fixing unit, and the guide member faces the surface of the recording material. It is also possible to adopt a configuration of a rotating body having a plurality of extended needle-like projections on the peripheral surface.

According to this structure, even if the needle-like projections of the rotating body are not directly fixed to the recording area of the recording material, the recording material is hard to be stained by the unfixed ink. There is no need to avoid such a situation, and a guide member that stably supports the recording material that has passed through the second ink discharge unit over substantially the entire surface thereof can be used.

[0015] In particular, the rotating body may be a plurality of disk-shaped members juxtaposed along the axis. According to this structure, the lower surface (back side) of the recording material can be stably formed as a whole in a simple configuration in which several very small disc-shaped members are arranged while being spaced apart in the axial direction. Thus, a supporting means which supports the unfixed ink and does not easily stain the unfixed ink is realized.

[0016] The fixing unit is provided with a pair of opposedly arranged inks for fixing the ink ejected by the first ink ejection unit and the ink ejected by the second ink ejection unit by heating. It can be configured as a rotating heat roller.

With this configuration, the ink ejected to the front side of the recording material by the first ink ejection unit and the ink ejected to the back side of the recording material by the second ink ejection unit are literally simultaneously printed on the recording material surface. An image output device capable of fixing and having a high processing speed is provided. In addition, since a phenomenon such as shrinkage that occurs in a part of the inside of the recording material due to heating from one side occurs in an accurate vertical symmetry with respect to the surface of the recording material, wrinkles and distortions occur in the fixed recording material. The resulting factors are reduced. Therefore, an excellent image output apparatus capable of outputting a printed matter having higher flatness is provided.

Other features and advantages of the present invention include:
The description will become apparent from the description of the embodiment using the drawings.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An ink jet printer shown in FIG. 1 is an example of an image output apparatus according to the present invention, and conveys a sheet-like recording paper 1 (an example of a recording material) along a substantially horizontal conveying surface P. A feeding mechanism 2 for feeding one sheet of recording paper 1 at a time to the feeding mechanism 6, a first ink ejection unit 12 for printing characters or images on the front side of the recording paper 1, and a fixing unit 20 And Further, the inkjet printer includes a second ink ejection unit 14 for printing characters, figures, and the like on the back side of the recording paper 1. The paper feeding unit 2 includes a tray 3 for storing a large number of recording papers stacked vertically and a pair of rotating rollers 4 capable of sandwiching the recording paper 1 from above and below and sending out the recording paper 1 from the tray 3. The transport mechanism 6 includes an endless belt 8 wound around a pair of rotating rollers 10a and 10b and a tension roller 10c. At least one of the pair of rotating rollers 10a and 10b is driven by an electric motor M1 to rotate the endless belt 8.

The upper portion of the endless belt 8 is formed between a pair of rotating rollers 10a and 10b to form a horizontal portion, and the recording paper 1 adsorbed and placed on the horizontal portion is formed on the horizontal portion. The trajectory formed based on the movement of the endless belt 8 coincides with the transport plane P described above. The endless belt 8 is used to transport the recording paper 1 in a sucked state.
It is charged with either negative or positive polarity by a corona discharge device (not shown) or the like disposed near the upstream rotating roller 10a. For this purpose, the endless belt 8 is made of a ferroelectric flexible material such as PI (polyimide).
In the vicinity of the downstream rotating roller 10b, a static eliminator (not shown) for temporarily weakening the charged state of the endless belt 8 so that the printed recording paper 1 is peeled off from the endless belt 8 on the downstream side of the transport mechanism 6. (Shown).

A first ink ejection unit 12 for ejecting ink to the front side of the recording paper 1 is provided above the transport mechanism 6.
It is arranged so as to face the recording paper mounting surface of the endless belt 8. The first ink ejection unit 12 is provided for each of the four colors CMYK arranged along the transport direction of the recording paper 1.
One print head 12C, 12M, 12Y, and 12K. Individual print heads 12C, 12M, 12
Y and 12K extend in the main scanning direction of the print head, that is, at right angles to the conveyance direction of the recording paper 1 (sub-scanning direction). The second ink ejection unit 14 for ejecting ink to the back side of the recording paper 1 is disposed downstream of the conveyance mechanism 6 so as to face the conveyance surface P located on the extension surface of the endless belt. The second ink ejection unit 14 is provided with the first
The recording head 1 is formed of a discharge head capable of forming a character or a graphic having fewer colors than the ink discharge unit 12 on the recording paper 1. Specifically, the second ink ejection unit 14
One print head 14 for a single color (here, black)
Consists of K. The print head 14K extends in the width direction of the recording paper 1.

On the downstream side of the transport mechanism 6, the recording paper 1
A guide member 16 for supporting the member from below is provided. As shown in FIG. 2, the guide member 16 includes a transition portion 16a extending in the main scanning direction, and a pair of extending members extending from both ends of the transition portion 16a in the sub-scanning direction and further downstream in the transport direction of the recording paper 1. And a support member 16b, 16c. The upper surface of the transition portion 16a and the upper surfaces of the pair of support portions 16b and 16c are connected to each other without any step, thereby forming one plane. On the downstream side of the transition portion 16a, the guide member 16
Is composed of only a pair of support portions 16b and 16c facing each other in the main scanning direction with a space 17 having a width W therebetween. The second ink ejection unit 14 is installed so as to be accommodated in the space 17 or such that the recording area of the recording paper 1 by the second ink ejection unit 14 is accommodated in the space 17. I have. In other words, the pair of support portions 16b, 16c provided on the guide member 16
Has a support surface for supporting the recording paper 1 via a portion outside the recording area where ink is ejected by the second ink ejection unit 14.

Accordingly, the downstream end (hereinafter simply referred to as the leading end) of the recording paper 1 on which the ink has been ejected to the front side by the first ink ejection unit 12 according to the carrying action of the carrying mechanism 6 is an endless belt. Almost at the same time as being separated from 8, the entire length in the main scanning direction is first supported by the upper surface of the transition portion 16a, and subsequently, the pair of support portions 16b, 1
While only both ends in the main scanning direction are supported by 6c, ink is ejected to the back side by the second ink ejection unit 14. Speaking of the recording area on the recording paper 1, on the downstream side of the second ink ejection unit 14,
Since the guide member 16 does not exist, there is no concern that the unfixed ink on the back side discharged by the second ink discharge unit 14 comes into contact with the guide member or the like and becomes soiled. The distance between the surface of the recording paper 1 adsorbed on the endless belt 8 and the leading end of each of the print heads 12C, 12M, 12Y, 12K, and 14K is 0.5 mm as an example of a distance appropriate for the ink to fly. It is kept at ± 0.2 mm.

A fixing section 20 is disposed further downstream of the downstream ends of the pair of support sections 16b and 16c. The fixing unit 20 is disposed downstream of the first ejection unit 12 and the second ejection unit 14 with respect to the transport direction of the recording paper 1. The fixing unit 20 includes a pair of rotating heat rollers 20 arranged so as to face each other from above and below.
a and 20b. Also, a pair of rotating heat rollers 2
Reference numerals 0a and 20b are provided so as to convey the recording paper 1 sandwiched between both rollers while applying a pressing force and heat necessary for fixing from both upper and lower directions. That is, first, ink is ejected to the front side of the recording paper 1 by the first ink ejection unit 12, and subsequently, the portion of the recording paper 1 to which the ink is ejected to the back side by the second ink ejection unit 14 is the leading end of the recording paper 1. Subsequently, the recording paper 1 is pushed out by the endless belt 8 through the middle portion or the rear half portion of the recording paper 1, so that the pair of support portions 16b,
16c, followed by a pair of rotating heat rollers 20.
a and 20b. A heater whose temperature can be controlled is incorporated in the rotary heat rollers 20a and 20b. In the nip, the sandwiching force and the heat from the heater are transmitted from both rollers to both the front and back surfaces of the recording paper 1. Thus, the fixing of the ink on both the front and back sides is performed almost simultaneously.

The lower surface of the recording paper 1 is composed of a base layer formed of paper or the like, while the upper surface of the recording paper 1 is composed of an image receiving layer formed on the base layer. About 1 in the image receiving layer
A resin that melts at 20 ° C. is contained in a form such as impregnation or application. That is, the ink ejected from the first ink ejection unit 12 adheres to the image receiving layer of the recording paper 1, while the ink ejected from the second ink ejection unit 14 adheres to the base layer of the recording paper 1. You. In addition, as the ink ejected from the first ink ejection unit 12 and the second ink ejection unit 14, a pigment-based ink including a liquid medium and a pigment dispersed in the liquid medium is used. The individual surfaces of the pigment are coated with a resin that melts at about 60 ° C.

Therefore, it is considered that the following phenomenon occurs when the recording paper 1 receiving the ink ejected from the first ink ejection unit 12 and the second ink ejection unit 14 passes through the fixing unit 20. That is, on the front side of the recording paper 1, that is, on the image receiving layer side, the resin adhering to the pigment contained in the first ink ejection unit 12 and the resin contained in the image receiving layer of the recording paper 1 mainly rotate upward. Heat roller 2
0a, which are melted by heat from the first heat-discharging unit 0a, and further spread by the stress from the upper rotating heat roller 20a, and are discharged onto the image receiving layer of the recording paper 1 from the first ink-discharging unit 12. Is established. As a result, the front side of the recording paper 1, that is, the surface of the image receiving layer is entirely covered with the resin film, and a glossy finished surface is obtained here. On the other hand, on the back side of the recording paper 1, that is, on the base layer, the second
The resin adhering to the pigment contained in the ink ejection unit 14 is mainly melted by heat from the lower rotary heat roller 20b, and is further recorded while being spread by the stress from the lower rotary heat roller 20b. The pigment of the ink ejected from the second ink ejection unit 14 is fixed on the base layer of the recording paper 1 by absorbing or adhering on the base layer of the paper 1.

The control device 22 provided in the ink jet printer includes a microprocessor, I / O, RA
M, ROM, etc., and functionally, as shown in FIG. 3, image processing means 24 for processing image data input through various media to create print data. Driving the respective print heads of the first ink ejection unit 12 and the second ink ejection unit 14 based on the print data created by the image processing means 24 (in other words, outputs a pulse signal for controlling ink ejection) And a motor control unit 28 that outputs a drive signal for driving the electric motor M1 based on the print data also generated by the image processing unit 24.

The image processing means 24 includes R (red), G (green), and B (color) to form a color image to be formed on the front side of the recording paper.
Image information input in the format of (blue) is C (cyan), M
(Magenta), Y (yellow), and K (black) are converted into image information, and a RAM for temporarily storing data in bitmap format is provided. The image information stored in the RAM is read out. Based on an apparent density value of an image to be formed, a pulse voltage having an appropriate characteristic is applied to each of a plurality of operation electrodes (not shown) provided on each print head 12.
, And a process for outputting a signal for driving the electric motor M1 by combining hardware and software.

The head controller 25 controls the print heads 12C, 12C based on the image information from the image processor 24.
It is configured by a combination of hardware and software to perform a process of outputting a pulse voltage at a timing of performing printing by designating a corresponding operation electrode among M, 12Y, and 12K. On the other hand, the motor control unit 28 performs a process of rotating and driving the endless belt 8 by a required amount in the direction indicated by the arrow by the electric motor M1.

Each print head 12C, 12M, 12
In Y and 12K, a cavity (not shown) capable of holding ink containing a pigment of a corresponding color is formed. On the lower surface of the print head, a number of ejection nozzles (not shown) communicating with the cavities are arranged so as to extend in the main scanning direction and open toward the supplied recording paper 1. I have. A large number of operation electrodes are arranged in each ejection nozzle along the main scanning direction. Therefore, when a predetermined positive pulse voltage is applied from the control device 22 to the operation electrode, a specific amount of pigment particles located in the vicinity of the discharge nozzle is in a liquid state by a repulsive force with the operation electrode having the same polarity as the pigment particles. In the form of ink droplets surrounded by a medium, the ink droplets protrude from the ejection nozzles so as to move away from the operation electrode. The ejected ink droplets are on the recording paper 1
And a dot of a specific size is formed on the recording paper 1. The above description about the print heads 12C, 12M, 12Y, and 12K of the first ink ejection unit 12 basically also applies to the print head 14K of the second ink ejection unit 14.

[Other Embodiments] <1> A guide member having the following configuration may be provided between the endless belt 8 and the fixing section 20. That is, the guide member 36 shown in FIG.
The two drive shafts 38a and 38b rotatably supported around the shaft cores X1 and X2 extending in parallel with the shafts a and 10b, and the shaft centers are disposed at predetermined positions on the circumference of the drive shafts 38a and 38b. Are fixed in a juxtaposed manner along
) Disk-shaped members 40. Individual disk-shaped members 40
Has a large number of needle-like projections 42 extending outward in the radial direction of the shaft cores X1 and X2. Each needle-like projection 42 has a sharp tip, and the tips of each needle-like projection 42 are all located on a substantially accurate common circle. Then, each drive shaft 38a,
Reference numeral 38b is rotationally driven so that the circumferential speed of a circumference formed by connecting adjacent tips of the needle-shaped protrusions 42 matches the circumferential speed of the endless belt 8. As a result, the lower surface of the recording paper 1 that is extruded downstream from the endless belt 8 always has a maximum of 12 rotating on the drive shafts 38a and 38b.
By the tip of each needle-like projection 42 of the disk-shaped member 40,
The sheet is fed to the fixing unit 20 while being substantially supported by point contact. As described above, when a guide member including a rotating body having a large number of needle-shaped protrusions extending toward the surface of the recording paper is used, the second ink ejection unit 14 is substantially the same as the guide member. Since the recording paper is supported via a plurality of point contacts, there is little concern that the recording paper surface will be stained with unfixed ink.
Therefore, the second ink ejection unit 14 having a sufficient length in the main scanning direction regardless of the installation area of the guide member
Can be provided.

<2> It should be noted that the disk-shaped member 40 is configured to rotate freely without being driven, based on the friction with the lower surface of the recording paper 1 extruded downstream from the endless belt 8. May be.

<3> In the above-described embodiment, assuming printing on a postcard having a color image on the front side and simple printing of a message or address in a single color such as black on the back side, The two-ink discharge unit 14 includes a black print head 14K. But, of course, the second
The ink ejection unit 14 may be constituted by a print head capable of ejecting two colors of ink, or, similarly to the first ink ejection unit 12, three or four colors such as C, M, Y, and K. A multi-color discharge unit including a print head capable of discharging color inks may be used.

<4> In the above-described embodiment, printing on a highly rigid sheet-like postcard having a color image on the front side and simple printing of a message or the like in a single color such as black on the back side. Although the present invention has been described on the assumption that the recording paper is not limited to a sheet, a roll-shaped recording paper or a recording paper having a low rigidity can basically be handled similarly as a recording paper.

<5> In the above embodiment, an ink jet printer is exemplified as the image output device according to the present invention, but the image output device also includes a copying machine using a wet toner. In this case, the wet toner constitutes the ink.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing an ink jet printer according to the present invention.

FIG. 2 is a perspective view showing the vicinity of a guide member of the ink jet printer of FIG.

FIG. 3 is a block diagram illustrating a control system of the inkjet printer of FIG. 1;

FIG. 4 is a perspective view schematically showing another embodiment of the guide member of the ink jet printer of FIG. 1;

[Explanation of symbols]

 Reference Signs List 6 transport mechanism 8 endless belt 12 first ink ejection unit 14 second ink ejection unit 16 guide member 20 fixing unit 36 guide member 38 drive shaft 40 disk-shaped member 42 needle-shaped protrusion

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C055 KK00 KK02 KK05 KK10 2C056 EA01 EA23 HA29 HA34 HA45 HA46 HA60 2C062 RA06

Claims (7)

[Claims] A transport mechanism configured to transport a recording material along a transport surface; a first ink discharge unit configured to discharge ink to a front side of the recording material transported by the transport mechanism; and a transport mechanism configured to transport the ink by the transport mechanism. And a second ejection unit for ejecting ink on the back side of the recording material, further comprising: an ink ejected by the first ink ejection unit and a second ink ejection unit. An image output device, wherein a fixing unit for fixing the ejected ink is disposed downstream of the first ejection unit and the second ejection unit in the transport direction. 2. The method according to claim 2, wherein the first discharge unit is at least C
2. The ejection unit according to claim 1, further comprising an ejection head capable of forming a photographic image on a recording material by ejecting ink of each color of MY, wherein the second ejection unit comprises an ejection head capable of forming a character or a figure on the recording material. Image output device. 3. The transport mechanism has an endless belt wound around at least a pair of rotating rollers, and the first ink discharge unit is arranged so as to face a recording material mounting surface of the endless belt. 3. The fixing device according to claim 1, wherein the fixing unit is disposed downstream of the endless belt, and the second ink discharge unit is disposed between the endless belt and the fixing unit. 4. Image output device. 4. A guide member capable of supporting the recording material is provided between the endless belt and the fixing unit,
The image output device according to claim 3, wherein the guide member includes a support surface that supports the recording material via a portion outside a recording area where ink is ejected by the second ink ejection unit. 5. A guide member capable of supporting the recording material is provided between the endless belt and the fixing unit,
The said guide member consists of a rotating body provided with many needle-shaped protrusions extended toward the surface of the said recording material on the peripheral surface.
2. The image output device according to 1. 6. The image output device according to claim 5, wherein the rotating body is a plurality of disk-shaped members arranged side by side along the axis. 7. The fixing unit is disposed so as to face each other to fix the ink ejected by the first ink ejection unit and the ink ejected by the second ink ejection unit by heating. The image output device according to any one of claims 1 to 6, comprising a pair of rotating heat rollers.