JPH11320851A - Inkjet printing equipment - Google Patents

Abstract

(57) Abstract: In an ink jet printing apparatus using phase change ink, a heater for preheating an intermediate transfer surface provided on an outer periphery of a drum to a predetermined temperature and a heater for heating a recording medium are commonly used. To improve energy efficiency and downsize the equipment. SOLUTION: A drum 1 and a drum-side paper guide 16 are provided.
a lamp heater 14 disposed in a space between the lamp heaters 14 in parallel to the axis of the drum 1, a reflector 15 for giving a directivity to the heat rays of the lamp heaters, and a heat ray of the lamp heaters 14 is always transferred to the intermediate transfer surface 1a. When the recording medium 5 passes through the paper guide 16 for transfer, the lamp heater 14 emits heat rays of the lamp heater 14 to the recording medium 5.
In addition to the means for changing the irradiation direction of the heat ray, the drum-side paper guide 16a is formed so that the heat ray of the lamp heater 14 can be easily transmitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an image for transfer by causing droplets of phase change ink to fly onto an intermediate transfer surface formed on an outer peripheral surface of a drum, and transferring the image to a recording medium. The present invention relates to an ink jet printing apparatus configured as described above.

[0002]

2. Description of the Related Art FIGS. 5 and 6 show, for example, JP-A-7-276.
621 shows a conventional ink jet printing apparatus using a phase change ink. FIG. 5 is a sectional view of a main part, and FIG. 6 is a perspective view of the main part with a part thereof cut away. In FIG. 1, reference numeral 1 denotes a drum which is formed of, for example, an aluminum material and is rotatably supported by a shaft 1b with an outer peripheral surface serving as an intermediate transfer surface 1a, which is controlled to rotate at a predetermined speed at all times. . Reference numeral 2 denotes an ink jet nozzle for ejecting the phase change ink droplet 3 onto the intermediate transfer surface 1a. In other words, in the initial state, the solid ink
This is for ejecting the ink that has been heated to about 150 ° C. and changed to a liquid. Reference numeral 4 denotes a heater for preheating the intermediate transfer surface 1a of the drum 1, which is provided near the intermediate transfer surface 1a so as to always heat the entire width of the drum 1. 5 is a recording medium, 6 is a guide plate for guiding the recording medium 5, and 7 is a heater that heats the recording medium 5 to a predetermined temperature and also serves as a guide plate.

Reference numeral 8 denotes a transfer roller, which is pressed against the intermediate transfer surface 1a of the drum 1 and is driven to rotate so as to pinch the recording medium 5 into a nip portion between the drum 1 and the ink droplets 3 on the intermediate transfer surface 1a. The image is transferred to the recording medium 5. Reference numeral 9 denotes a release member for separating the recording medium 5 onto which the image has been transferred from the intermediate transfer surface 1a when the recording medium 5 remains on the intermediate transfer surface 1a. Reference numeral 10 denotes a liquid application device. A liquid such as an agent or silicone oil is applied to the intermediate transfer surface 1a of the drum 1 to form a liquid film. This liquid film accurately holds the position of the ink droplet 3 that has landed,
When the ink droplets 3 are transferred to the recording medium 5, the ink droplets 3 are prevented from remaining on the intermediate transfer surface 1a. The liquid application device 10 is normally located at a position away from the intermediate transfer surface 1a, and uses a rotation of the drum 1 by bringing a liquid application member such as a nonwoven fabric impregnated with a liquid into contact with the intermediate transfer surface 1a before image formation. Thus, a liquid film is formed on the entire surface of the intermediate transfer surface 1a.

In FIG. 6, reference numeral 11 denotes a temperature controller which detects the temperature of the intermediate transfer surface 1 a by a temperature sensor 12 and controls heating by the heater 4 and cooling by the blower 13. By this control, the intermediate transfer surface 1a is kept in a specified temperature range (for example, 40 ° C. to 55 ° C.). The drum 1 is hollow, and the intermediate transfer surface 1a is supported by a plurality of ribs 1c radially formed from a shaft 1b, so that cooling air from the blower 13 passes between the ribs 1c.

Next, the operation will be described. In the ink jet nozzle 2, the ink is heated to reduce its viscosity to be in a liquid state. In accordance with an instruction from a control unit (not shown), the drum 1 is rotated at a constant speed, and the inkjet nozzles 2 are scanned in the axial direction of the drum 1 while the ink droplets 3 are made to correspond to the formed image on the intermediate transfer surface 1a. Let it fly. The intermediate transfer surface 1a is maintained in a specified temperature range where the ink does not solidify and does not flow, and is caused to fly on the intermediate transfer surface 1a to form an image by the ink droplets 3. When the portion where the ink droplets 3 adhered comes to the position of the transfer roller 8 due to the rotation of the drum 1, the recording medium 5 fed in synchronism therewith is sandwiched between the transfer roller 8 and the intermediate transfer surface 1 a. The drum 1 is rotated in the state. By this rotation, the ink droplets 3 on the intermediate transfer surface 1a are transferred to the recording medium 5
Transfer to At this time, the recording medium 5 is heated by the heater 6 to a temperature slightly higher than the temperature of the intermediate transfer surface 1a. Transfer to The ink droplets 3 transferred to the predetermined surface of the recording medium 5 are cooled to form an image.

[0006]

In the conventional ink jet printing apparatus as described above, the intermediate transfer surface 1 is provided inside the apparatus.
requires two heaters, a heater 4 for heating a to a predetermined temperature and a heater 7 for heating the recording medium 5;
Each time the recording medium 5 is conveyed, the heater 7 must be continuously energized at all times because it needs to be rapidly heated. Therefore, there is a problem that the energy loss is large and the device becomes large.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide an ink jet printing apparatus which can reduce the energy loss and can be downsized.

[0008]

An ink jet printing apparatus according to the present invention has a lamp heater disposed in a space between a drum and a paper guide on a drum side in parallel with the axis of the drum, and has a directivity to heat rays of the lamp heater. And a lamp heater so that the heat ray of the lamp heater is always radiated to the intermediate transfer surface, and the heat ray of the lamp heater is radiated to the recording medium when the recording medium passes through the paper guide for transfer. A means for changing the irradiation direction of the heat rays is provided, and the drum-side paper guide is formed so that the heat rays of the lamp heater can be easily transmitted.

Further, the paper guide is formed in a curved surface along the intermediate transfer surface of the drum.

Further, a plurality of lamp heaters are arranged along the intermediate transfer surface of the drum.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 1 and 2
FIG. 1 shows an ink jet printing apparatus using a phase change ink according to Embodiment 1 of the present invention. FIG. 1 shows a state in which a lamp heater heats a recording medium, and FIG. 2 shows a state in which the lamp heater preheats an intermediate transfer surface. Is shown. In the figure,
Reference numeral 1 denotes a drum which is formed of, for example, an aluminum material, and is rotatably supported by a shaft 1b with an outer peripheral surface serving as an intermediate transfer surface 1a, and is controlled to constantly rotate at a predetermined speed. 2 is a phase change ink droplet 3 on the intermediate transfer surface 1a.
Nozzles, 5 are recording media, 8
Reference numeral denotes a transfer roller, which is pressed against the intermediate transfer surface 1a of the drum 1 and is driven to rotate, thereby sandwiching the recording medium 5 in a nip portion between the drum 1 and the ink droplets 3 on the intermediate transfer surface 1a to the recording medium 5. Transcribe. Reference numeral 9 denotes a peeling member for separating the recording medium 5 from the intermediate transfer surface 1a, and reference numeral 10 denotes a liquid application device which applies a liquid such as a surfactant or silicone oil to the intermediate transfer surface 1a of the drum 1. It forms a liquid film. These are the same as the above-mentioned conventional apparatus.

Reference numeral 14 denotes a columnar lamp heater for maintaining the drum 1 at a predetermined temperature and heating the recording medium 5. Reference numeral 15 denotes a reflector for efficiently concentrating the heat of the lamp heater 14. The reflector 15 is provided rotatably around the long axis of the lamp heater 14. As the lamp heater 14, an infrared lamp, a halogen lamp, or the like is suitable for use. Reference numeral 16 denotes a paper guide, which includes a drum-side paper guide 16a and a transfer roller-side paper guide 16b opposed to the recording medium 5 with a gap therebetween. The drum-side paper guide 16a provided on the lamp heater 14 side, that is, on the drum 1 side, is formed so as to guide the recording medium 5 without blocking the radiant heat of the lamp heater 14. That is, the wires are arranged in a grid shape with the feeding direction of the recording medium 5 being elongated, and the feeding of the recording medium 5 is not hindered. Can be applied to the recording medium 5.

The transfer roller-side paper guide 16b is made of a heat insulating material to prevent the radiant heat of the lamp heater 14 from radiating to the outside. Reference numeral 17 denotes a registration roller, and the stopped registration roller 17 corrects the skew of the leading end of the recording medium 5 sent from a paper feeding device (not shown).
The recording medium 5 starts rotating in synchronization with the image position on the intermediate transfer surface 1a and passes through the paper guide 16 to transfer the recording medium 5 to the transfer roller 8
To the drum 1 nip. A paper sensor 18 detects the recording medium 5. The paper sensor 18 detects that the recording medium 5 is prepared at the position of the registration roller 17 and detects the rear end of the recording medium 5.

FIG. 3 is a perspective view of a lamp heater portion.
In the figure, 14 is a lamp heater, and 15 is a reflector for concentrating the heat of the lamp heater 14, which is the same as that described above. Reference numeral 19 denotes a lamp bracket for supporting the lamp heater 14 from both ends, and a reflector 15 is attached to the lamp bracket 19 by a support 19a. A support shaft 20 extends from the lamp bracket 19 and rotatably supports the lamp heater 14 and the reflector 15. The support shaft 20 is hollow, and a lead wire for supplying electricity to the lamp heater 14 is wired through the hollow portion. Reference numeral 21 denotes a forward / reverse rotatable motor,
0 through the gear 22 attached to the lamp heater 14.
And the reflector 15 is rotated.

Next, the operation of the ink jet printing apparatus configured as described above will be described. in this case,
Since the image forming operation is the same as that of the above-described conventional example, the description is omitted, and the heating of the intermediate transfer surface 1a and the recording medium 5 by the lamp heater 14 and the reflector 15, which are main parts of the present invention, will be described. That is, as shown in FIG. 2, usually, in order to preheat the intermediate transfer surface 1a and maintain the intermediate transfer surface 1a in a specified temperature range, the reflector 15 is configured to transfer the heat of the lamp heater 14 to the intermediate transfer surface 1a. Towards. In this state, the temperature of the intermediate transfer surface 1a is maintained in a specified temperature range.
A temperature controller (not shown) adjusts power to the lamp heater 14 and controls the amount of air blown by the blower 13 based on the detection result of the temperature sensor (not shown). This control operation is the same as that of the above-described conventional device, and the detailed description is omitted.

Next, when the image formation by the ink droplets is completed on the intermediate transfer surface 1a, the registration roller 17 is rotated at a timing when the leading edge of the image coincides with the leading edge of the recording medium 5, and the recording medium 5 is moved to the paper guide 16 Drum 1 through
Is fed to the nip portion of the transfer roller 8. At this time, the feeding speed of the recording medium 5 is set to be equal to the peripheral speed of the drum 1. Then, the motor 21 is driven at the same time as the rotation start command of the registration roller 17 to turn the reflector 15 toward the paper guide 16 as shown in FIG. 1, and the lamp heater 14 is held at the heating output of the recording medium 5. Therefore, the recording medium 5 is heated while passing through the paper guide 16, reaches the nip portion of the transfer roller 8, and an image is transferred to the recording medium 5. After a predetermined time from when the paper sensor 18 detects the trailing edge of the recording medium 5 to when the trailing edge of the recording medium 5 passes through the nip portion with the transfer roller 8, the motor 21 is reversed to direct the reflector 15 toward the drum 1. To prepare for reheating of the intermediate transfer surface 1a.

Since the recording medium 5 is preheated at the internal temperature of the apparatus, a predetermined temperature can be easily heated by the heater 6 even while the recording medium 5 is being fed. Further, the direction of the lamp heater 14 is changed from the drum 1 to the recording medium 5.
, The required temperature of the intermediate transfer surface 1a is maintained by the residual heat of the lamp heater 14 and the temperature inside the apparatus.

As described above, the lamp heater 14 having the reflector 15 is disposed between the paper guide 16 and the intermediate transfer surface 1a, and the preheat of the intermediate transfer surface 1a and the heating of the recording medium 5 are performed by turning the reflector 15 around. By performing the switching by moving, the energy loss can be reduced and the size of the ink jet printing apparatus can be reduced. Note that the reflector 15 can be configured to rotate independently of the lamp heater 14. Although the first guide member 16a has been described as being formed by arranging wires in a grid pattern, the first guide member 16a may be formed of a transparent quartz glass plate having good transmission of radiant heat rays.

Embodiment 2 FIG. 4 is a sectional view of an ink jet printing apparatus using the phase change ink according to the second embodiment of the present invention. In the figure, 1 is a drum, 2 is an inkjet nozzle, 3 is an ink droplet, 5 is a recording medium,
Reference numeral 8 denotes a transfer roller, 9 denotes a peeling member, and 10 denotes a liquid application device. 14 is a cylindrical lamp heater, 15 is a reflector for concentrating the heat of the lamp heater 14, 16 is a paper guide, 17 is a registration roller, and 18 is a paper sensor for detecting the recording medium 5. These are the same as those described in the first embodiment.

In the second embodiment, as shown in FIG. 4, the paper guide 16 is formed in a curved surface along the intermediate transfer surface 1a. With this configuration, the relationship with the recording medium 5 is formed in a shape close to a semicircle centered on the lamp heater 14. Therefore, the interval between the recording medium 5 and the lamp heater 14 near the registration roller 17 and the transfer roller 8, that is, the interval between the entire recording medium 5 and the lamp heater 14 becomes small, and the heating of the recording medium 5 during Efficiency can be improved.

Further, by forming the paper guide 16 with a curved surface, the distance between the facing portion of the intermediate transfer surface 1a and the recording medium 5 can be made longer if necessary. Becomes possible. Lamp heater 14
Is provided, the facing area between the lamp heater 14 and the recording medium 5 increases. That is, when heating the recording medium 5 with one lamp heater 14, the lamp heater 1
4 needs to be kept at a high temperature. Therefore, when the recording medium 5 passes nearby, the recording medium 5 may be discolored or burnt. On the other hand, if the heating is performed by a plurality of lamp heaters 14 having an appropriate temperature, this problem can be prevented. Also, in preheating the intermediate transfer surface 1a, when the intermediate transfer surface 1a is irradiated by the high-temperature lamp heater 14, the intermediate transfer surface 1a is heated.
Since the ink formed on a melts and hinders the sharpness of the image, the use of a plurality of lamp heaters 14 at appropriate temperatures is effective in terms of thermal efficiency and maintaining image quality.

[0022]

Since the present invention is configured as described above, it has the following effects.

The direction of irradiation of the heat rays of the lamp heater is such that the heat rays of the lamp heater are normally irradiated on the intermediate transfer surface, and when the recording medium passes through the paper guide for the transfer, the heat rays of the lamp heater are irradiated on the recording medium. Since the means for converting is provided, an ink-jet printing apparatus which can reduce the energy loss and downsize the apparatus can be obtained.

Further, in the case where the paper guide is formed in a curved surface along the intermediate transfer surface of the drum, a plurality of lamps can be installed, so that the distance between the entire recording medium 5 and the lamp heater 14 becomes small, and the recording medium becomes short. 5, the heating efficiency is improved, and an ink jet printing apparatus having good image quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a principal part showing a recording medium heated state of an inkjet printing apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of the ink jet printing apparatus according to the first embodiment of the present invention, showing a preheated state of an intermediate transfer surface.

FIG. 3 is a perspective view of a lamp heater portion of the present invention.

FIG. 4 is a sectional view of a main part of an ink jet printing apparatus according to a second embodiment of the present invention.

FIG. 5 is a sectional view of a main part of a conventional inkjet printing apparatus.

FIG. 6 is a perspective view of a main part of a conventional inkjet printing apparatus.

[Explanation of symbols]

1 drum, 1a intermediate transfer surface, 2 ink jet nozzle, 3 ink droplets, 5 recording medium, 8 transfer roller, 14 lamp heater, 15 reflector, 16 paper guide, 16a drum side paper guide, 16b transfer roller side paper guide, 17 registration rollers, 18
Paper sensor.

Claims (3)

[Claims] 1. A drum having an intermediate transfer surface formed on an outer peripheral surface thereof, wherein a drum for phase change ink is ejected on the intermediate transfer surface to form an image for transfer, and an intermediate transfer of the drum. A transfer roller, which is driven to rotate by being pressed against the surface and acts to transfer an image formed on the drum to a recording medium, and the recording medium for guiding the recording medium to a nip portion between the drum and the transfer roller. A paper heater provided on a transfer roller side and a drum side of a medium passage; a lamp heater disposed in a space between the drum and the drum side paper guide in parallel with an axis of the drum; A reflector that directs the heat rays of the heater and the heat rays of the lamp heater are normally irradiated on the intermediate transfer surface, and when the recording medium passes through the paper guide for transfer. Means for changing the irradiation direction of the heat rays of the lamp heater so as to irradiate the heat rays of the lamp heater to the recording medium, so that the heat rays of the lamp heater can be easily transmitted through the paper guide on the drum side. An ink-jet printing apparatus characterized by being formed. 2. The ink jet printing apparatus according to claim 1, wherein the paper guide is formed to have a curved surface along the intermediate transfer surface of the drum. 3. The lamp heater according to claim 2, wherein a plurality of lamp heaters are arranged along the intermediate transfer surface of the drum.
An inkjet printing apparatus as described in the above.