JPH07319292A - Wet type image forming device - Google Patents

Abstract

PURPOSE:To prevent the destruction of an image due to the recording paper for press fixing with the fixing device left standing in a state of wet with the solvent by providing the heating source and the mirror, for irradiating the surface of the recording paper with the focal heat ray emitted from the heating source, between the transfer device and the fixing device. CONSTITUTION:Between the transfer device and the separating device 3, the heating wire 5 as a heating source is provided in parallel to the surface of the transporting belt 2 and orthogonal to the transporting direction of the recording paper 1, and more the heat ray focusing mirror 7 is provided for covering the periphery of the heating wire 5 over the approximately semicircle and for focally irradiating the surface of the recording paper 1 transported by the transporting belt 2 with the heat ray 6 emitted from the heating wire 5. When the recording paper 1 is allowed to pass the position opposed to the heating wire 5 before reading the fixing device 4, the surface of the recording paper 1 is focally irradiated with the heat ray 6 emitted from the heating wire 5 by the heat ray focusing mirror 7. Thus, the recording paper 1 is made dry, as the evaporation of the solvent stuck to the recording paper 1 is accelerated by the heat ray 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet image forming apparatus using a developing solution in which a toner is dissolved in a solvent.

[0002]

2. Description of the Related Art Conventionally, in a wet copying machine or a wet printer, which is a wet image forming apparatus using a developing solution in which a toner is dissolved in a solvent, when the image is transferred onto the recording paper, The solvent also adheres to the recording paper, and the recording paper gets wet with the adhered solvent. Especially, in a color copying machine or the like, which repeats transfer four times continuously to one recording paper, the solvent adheres to the recording paper. The amount of When the recording paper to which the solvent adheres is pressure-fixed by the fixing device, the image transferred to the recording paper is crushed and the image quality is deteriorated.

Therefore, it is possible to remove the solvent adhering to the recording paper before the pressure fixing by the fixing device.
It is possible to absorb the solvent by bringing a hygroscopic material such as a urethane roller into contact with the recording paper before fixing.
No. 174, JP-A-62-26787, and JP-A-63-4249.

It has also been proposed to evaporate the solvent adhering to the recording paper by raising the temperature of the entire conveying path of the recording paper.

[0005]

However, when a hygroscopic material such as a urethane roller is brought into contact with the recording paper before fixing,
The image transferred on the recording paper is disturbed and the image quality is deteriorated.

Further, if the temperature of the entire recording paper conveyance path is raised, the power consumption rises and the running cost increases, and moreover, the heat from this conveyance path adversely affects various circuits and parts. However, there is an inconvenience that durability is reduced.

[0007]

The invention according to claim 1 is
In a wet image forming apparatus using a developing solution in which a toner is dissolved in a solvent, a transfer device for transferring an image formed on a photoconductor to a recording sheet and a fixing device for fixing the recording sheet on which the image is transferred under pressure. A heat generating source and a heat ray focusing mirror that focuses and irradiates the heat ray radiated from the heat source toward the surface of the recording paper on which the image is transferred are provided between the heat source and the heat source.

According to a second aspect of the present invention, in the first aspect of the present invention, an air blowing means is provided for blowing air toward a focused irradiation spot of the heat ray by the heat ray focusing mirror.

According to a third aspect of the present invention, in the first aspect of the present invention, a heat ray transmitting member is provided between the heat source and the recording paper to block evaporated solvent vapor and to transmit heat rays.

According to a fourth aspect of the present invention, in the first aspect of the present invention, a detection sensor for detecting that the recording paper is conveyed to a position upstream of the heat source along the recording paper conveyance direction, and this detection sensor. A control unit for controlling on / off of the heat source based on the detection result from the sensor is provided.

According to a fifth aspect of the present invention, in the first aspect of the present invention, a contact heating member is provided between the transfer device and the fixing device to contact the back surface of the recording paper to heat the recording paper.

According to a sixth aspect of the invention, in the fifth aspect of the invention, negative pressure generating means for bringing the recording paper into suction contact with the contact heating member is provided.

[0013]

According to the invention described in claim 1, the heat rays emitted from the heat source are focused and irradiated toward the surface of the recording sheet by the heat ray focusing mirror, and the recording sheet is dried by evaporating the solvent adhering to the recording sheet. When the recording sheet is pressure-fixed by the fixing device, the image is prevented from being crushed due to the wet state. Since the recording sheet is dried by the heat source and the heat ray focusing mirror in a non-contact state with the recording sheet, the image transferred to the recording sheet is not disturbed, and the heat source is the recording sheet. Since it does not raise the temperature of the entire transport path of, the power consumption is small.

According to the second aspect of the invention, the solvent vapor evaporated by the air blown by the air blower is blown away, which further promotes the evaporation of the solvent from the recording paper, and the solvent vapor comes into contact with the heat source. The occurrence of ignition is prevented.

According to the third aspect of the present invention, the evaporated solvent vapor is blocked by the heat ray transmitting member and prevented from coming into contact with the heat source, and the occurrence of ignition due to the contact of the solvent vapor with the heat source is reliably prevented. To be done.

According to the fourth aspect of the present invention, after the detection sensor detects that the recording paper has been conveyed, the heat source is turned on by the control of the control unit, thereby preventing unnecessary heat radiation from the heat source. The power consumption is reduced. In addition, an increase in the ambient temperature due to unnecessary radiation of heat rays from the heat source is suppressed, and it is possible to prevent damage to parts and circuits arranged around the heat source due to unnecessary heating. .

According to the fifth aspect of the invention, the recording paper is also heated from the back side by the contact heating member, so that the evaporation of the solvent is further promoted.

According to the sixth aspect of the invention, since the recording paper is brought into suction contact with the contact heating member by the negative pressure generating means, evaporation of the solvent by the heating of the contact heating member is promoted.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the invention described in claim 1 will be described with reference to FIGS. A wet copying machine, which is a wet image forming apparatus, is provided with a conveyor belt 2 for conveying the recording paper 1. From the upstream side along the conveying direction of the recording paper 1 (direction of arrow a) by the conveyor belt 2. A transfer device (not shown) that transfers the image formed on the photoconductor (not shown) to the surface of the recording paper 1 in order toward the downstream side, and the recording paper 1 on which the image is transferred is separated from the conveyor belt 2. A separating device 3 is provided, and a fixing device 4 for fixing the recording paper 1 under pressure is provided in the direction in which the recording paper 1 separated from the conveyor belt 2 is conveyed.

Next, a heating wire 5 as a heat source is provided between the transfer device and the separating device 3 in a direction parallel to the surface of the conveyor belt 2 and orthogonal to the conveying direction of the recording paper 1. Further, the heating wire 5 covers the circumference of the heating wire 5 for about half a circumference, and the heating wire 6 emitted from the heating wire 5 is focused and radiated toward the surface of the recording paper 1 being conveyed by the conveyor belt 2. A mirror 7 is provided. The heat ray focusing mirror 7 is formed by vacuum-depositing a metal such as aluminum, silver, or copper on the surface thereof. Further, the heating wire 6 radiated from the heating wire 5 is 1.5 to
It is considered to be near infrared light having a wavelength of 15 μm.

In such a structure, when the recording paper 1 conveyed by the conveyor belt 2 passes through the transfer device, the image formed on the photoconductor is transferred to the surface of the recording paper 1.
At this time, the solvent dissolving the toner adheres to the recording paper 1 and the recording paper 1 becomes wet.

Next, the recording paper 1 on which the image has been transferred by the transfer device is conveyed toward the fixing device 4 by the conveyor belt 2. When the recording paper 1 passes through the position facing the heating wire 5 before reaching the fixing device 4, the heating wire 6 radiated from the heating wire 5 is transferred to the surface of the recording paper 1 by the heating wire focusing mirror 7. The heat ray 6 accelerates the evaporation of the solvent adhering to the recording paper 1, and the recording paper 1 dries. Therefore, when the recording paper 1 is pressure-fixed by the fixing device 4, the image is prevented from being crushed because the recording paper 1 is in a wet state, and an image of good quality can be obtained.

Since the recording paper 1 is dried by the heating wire 5 and the heat-ray focusing mirror 7 in a non-contact state with respect to the recording paper 1, the image transferred onto the recording paper 1 is not disturbed. . In addition, the heating wire 6 radiated from the heating wire 5
Does not raise the temperature of the entire conveyance path of the recording paper 1, and consumes little power.

Next, a second embodiment of the invention described in claim 1 will be described with reference to FIG. The same parts as those described in FIGS. 1 and 2 are designated by the same reference numerals, and description thereof will be omitted (same below). In this embodiment, a heating wire 5 and a heat-ray focusing mirror 7 are provided between the separating device 3 and the fixing device 4,
The heat ray 6 is focused and irradiated onto the recording paper 1 after being separated from the conveyor belt 2 and before reaching the fixing device 4.

Therefore, the recording paper 1 on which the heat rays 6 are focused and irradiated
Is a state in which the solvent is separated from the conveyor belt 2, and evaporation of the solvent from the recording paper 1 is accelerated by the focused irradiation of the heat rays 6. For this reason, the drying of the recording paper 1 is promoted more than when the recording paper 1 positioned on the transport belt 2 is focused and irradiated with the heat rays 6, and the crushing of the image during the pressure fixing is further prevented, and further An image of good quality can be obtained.

Next, one embodiment of the invention of claim 2 will be described with reference to FIG. In this embodiment, the heating wire 5 and the heating wire focusing mirror 7 are provided at a position facing the recording paper 1 that is conveyed toward the fixing device 4 after the image is transferred.
Further, an air blower 8 is provided to blow air from the rear of the heating wire 5 toward the focused irradiation position of the heating wire 6.

In such a structure, the heat rays 6 are focused and irradiated onto the recording paper 1 to accelerate the evaporation of the solvent from the recording paper 1. Then, by blowing air toward the focused irradiation spot of the heat ray 6 by the blowing means 8, the solvent vapor 9 evaporated from the recording paper 1 is blown off from the surface portion of the recording paper 1, and the solvent is further evaporated from the recording paper 1. This accelerates the drying of the recording paper 1. Further, the solvent vapor 9 blown off by the blowing means 8 prevents the solvent vapor 9 evaporated from the recording paper 1 from staying around the heating wire 5 and contacts the heating wire 5. The occurrence of ignition due to the contact of the solvent vapor 9 with the heating wire 5 is prevented. By directing the blowing direction from the rear of the heating wire 5 toward the recording paper 1 side, it is possible to reliably prevent the solvent vapor 9 that has been blown off from contacting the heating wire 5 and igniting.

Next, a first embodiment of the invention according to claim 3 will be described with reference to FIGS. In this embodiment, a heating wire 5 and a heating wire focusing mirror 7 are provided at a position facing the recording paper 1 which is conveyed toward the fixing device 4 after the image is transferred, and further, the heating wire 5 and the recording paper 1 are provided. Between the recording paper 1
A heat ray transmissive member 10 that shields the solvent vapor 9 evaporated from the heat ray and transmits the heat ray 6 is provided. The heat ray transmitting member 10 is formed in a flat plate shape and is attached so that the open portion of the heat ray focusing mirror 7 is closed. Also,
The heat ray transmitting member 10 is preferably formed of a material having a high near infrared ray transmittance, and specifically, synthetic sapphire, silicon, or the like is used. 6 and 7 are graphs showing the external spectral transmittance of optical materials listed in the Meliss Griot company catalog. FIG. 6 is the external spectral transmittance of a synthetic sapphire with a thickness of 1 mm, and FIG. 7 is the silicon with a thickness of 2 mm. Is the external spectral transmittance of.

In such a structure, the heat ray transmitting member 10 reliably prevents the solvent vapor 9 from coming into contact with the heating wire 5, and ensures that the solvent vapor 9 comes into contact with the heating wire 5 and ignites. To be prevented.

Next, a second embodiment of the invention according to claim 3 will be described with reference to FIG. In this embodiment, a heating wire 5 and a heating wire focusing mirror 7 are provided at a position facing the recording paper 1 which is conveyed toward the fixing device 4 after the image is transferred, and further, the heating wire 5 and the recording paper 1 are provided. A heat ray transmissive member 11 that intercepts the solvent vapor 9 evaporated from the recording paper 1 and transmits the heat ray 6 is provided between the two. The heat ray transmitting member 11 is formed in a cylindrical shape that surrounds the heating wire 5, and is made of synthetic sapphire, silicon, or the like.

With this structure, the solvent vapor 9 is surely prevented from coming into contact with the heating wire 5 and the solvent vapor 9 comes into contact with the heating wire 5 and ignites. To be prevented.

Next, a first embodiment of the invention described in claim 4 will be described with reference to FIG. In this embodiment, a heating wire 5 and a heating wire focusing mirror 7 are provided at a position facing the recording paper 1 that is conveyed toward the fixing device 4 after the image is transferred, and the recording paper 1 is the heating wire 5 or the like. To a position opposite to, and based on the detection result from the detection sensor 12, the heating wire 5 is energized and the recording paper 1 detects the detection sensor 12. A control unit (not shown) that turns off the power supply to the heating wire 5 after a predetermined time has passed after the passage.

In such a structure, when the recording paper 1 conveyed by the conveyor belt 5 approaches the position facing the heating wire 5 or the like and is detected by the detection sensor 12, the heating wire 5 is energized to record. Focused irradiation of the heat ray 6 on the paper 1 is started. In addition, after a lapse of a predetermined time after the recording paper 1 passes through the detection sensor 12, the heating wire 5 is deenergized. Therefore, unnecessary heating due to radiation of the heating wire 6 from the heating wire 5 is prevented, and power consumption is reduced. In addition, an increase in the ambient temperature due to unnecessary radiation of the heating wire 6 from the heating wire 5 is suppressed, and it is possible to prevent components and circuits arranged around the heating wire 5 from being damaged by unnecessary heating. To be done.

Next, a second embodiment of the invention described in claim 4 will be described with reference to FIG. This embodiment is provided with a reflection type detection sensor 13 in place of the transmission type detection sensor 12 shown in FIG. 9, and other configurations are the same as those of the embodiment shown in FIG.

Also in this embodiment, since the heating wire 5 is energized only while the recording paper 1 carried by the carrying belt 2 passes through the position facing the heating wire 5, the heating wire 5 is turned on. Unnecessary heating due to radiation of the heat rays 6 is prevented,
In addition to reducing power consumption, it is possible to prevent components and circuits arranged around the heating wire 5 from being damaged by unnecessary heating.

Next, an embodiment of the invention described in claim 5 will be described with reference to FIG. In this embodiment, a heating wire 5 and a heat-ray focusing mirror 7 are provided between the separating device 3 and the fixing device 4, and further separated from the conveyor belt 2 between the separating device 3 and the fixing device 4. Further, a contact heating member 14 for heating the recording paper 1 by contacting the back surface of the recording paper 1 is provided. The heating temperature of the contact heating member 14 is kept below the melting point of the toner resin.

In such a structure, the heating wire 6 from the heating wire 5 is focused and irradiated on the front surface of the recording paper 1 and the back side of the recording paper 1 is heated by the contact heating member 14, so that the solvent from the recording paper 1 is heated. Is greatly accelerated, and the recording paper 1 is dried extremely well. Therefore, when the recording paper 1 is pressure-fixed by the fixing device 4, the image collapse due to the wet state of the recording paper 1 is surely prevented, and an image of extremely good image quality can be obtained.
Since the heating temperature of the contact heating member 14 is suppressed below the melting point of the toner resin, even if an image is formed on the opposite side of the recording paper 1 on which an image is already formed on one side, it is already formed. The toner resin of the image on the contact heating member 14
It is prevented that the toner is melted by heating and the toner resin of the image already recorded is melted and the image is disturbed.

Next, an embodiment of the invention described in claim 6 will be described with reference to FIG. In this embodiment, in addition to the embodiment shown in FIG. 11, a negative pressure generating means 15 for bringing the conveyed recording paper 1 into contact with the contact heating member 14 by suction is provided.

In such a structure, the negative pressure generating means 1
The recording 1 is surely brought into contact with the contact heating member 14 by the suction air resistance generated in 5, and the evaporation of the solvent from the recording paper 1 and the drying of the recording paper 1 are further promoted.
Then, the image is further prevented from being crushed at the time of pressure fixing by the fixing device 4, and an image having a better image quality can be obtained.

[0040]

As described above, according to the first aspect of the present invention, in the wet image forming apparatus using the developing solution in which the toner is dissolved in the solvent, the transfer for transferring the image formed on the photoreceptor to the recording paper is performed. A heat source and heat rays radiated from the heat source are focused and radiated toward the surface of the recording sheet having the image transferred between the apparatus and a fixing device for fixing the pressure of the recording sheet having the image transferred. Since the heat ray focusing mirror is provided, it is possible to evaporate the solvent adhering to the recording paper before the pressure fixing by the fixing device to dry the recording paper, so that the fixing device is pressure-fixed. It is possible to prevent the image from being crushed due to the recording paper remaining wet with the solvent, which makes it possible to obtain an image of good quality without image crushing, and moreover, a heat source. And heat ray focusing mirror Since the recording paper is dried in a non-contact state with the recording paper, it is possible to prevent disturbing the image transferred to the recording paper. Since it does not increase the power consumption, it has the effect of suppressing the power consumption to a small value.

As described above, the invention according to claim 2 is, in the invention according to claim 1, provided with a blowing means for blowing air toward a heat radiation focusing irradiation position by the heat ray focusing mirror.
By blowing off the solvent vapor evaporated from the recording paper by blowing air from the blowing means, the evaporation of the solvent from the recording paper can be promoted and the recording paper can be further dried, which results in better image quality without image collapse. It is possible to obtain an image of and to prevent the occurrence of ignition due to the contact of the solvent vapor with the heat source.

According to the third aspect of the invention, as described above, in the first aspect of the invention, a heat ray transmitting member is provided between the heat source and the recording paper to block evaporated solvent vapor and to transmit heat rays. Therefore, it is possible to surely prevent the evaporated solvent vapor from coming into contact with the heat source, and thus it is possible to reliably prevent the occurrence of ignition due to the contact of the solvent vapor with the heat source. .

As described above, the invention according to claim 4 is, in the invention according to claim 1, a detection sensor for detecting that the recording paper has been conveyed to a position upstream from the heat source along the conveying direction of the recording paper. And, since the control unit for controlling the on / off of the heat source based on the detection result from the detection sensor is provided, the heat ray can be emitted from the heat source only when the detection sensor detects the recording paper, Therefore, it is possible to reduce waste of power consumption due to unnecessary radiation of heat rays from the heat source, and it is possible to suppress an increase in ambient temperature due to unnecessary radiation of heat rays from the heat source. It is possible to prevent the parts and circuits arranged in the periphery from being damaged by receiving unnecessary heating.

As described above, the invention according to claim 5 is, in the invention according to claim 1, characterized in that, between the transfer device and the fixing device, a contact heating member for contacting the back surface of the recording paper to heat the recording paper is provided. Since it is provided, the recording paper can be heated from the front surface side of the recording paper by the heat source and the heat ray focusing mirror, and also from the back surface side of the recording paper by the contact heating member. Of the image and the drying of the recording paper can be further promoted, and therefore, it is possible to further prevent the image from being crushed at the time of pressure fixing by the fixing device, and to obtain an image of better image quality. And so on.

According to the sixth aspect of the invention, as described above, in the fifth aspect of the invention, since the negative pressure generating means for bringing the recording paper into suction contact with the contact heating member is provided, the recording paper can be securely applied to the contact heating member. The contact heating member can further accelerate the evaporation of the solvent from the recording paper, and the evaporation of the solvent from the recording paper in combination with the evaporation effect of the solvent by the heat source and the heat ray focusing mirror. Further, it is possible to further accelerate the drying of the recording paper, and therefore, it is possible to further prevent the image from being crushed during the pressure fixing by the fixing device, and to obtain an image with a better image quality. .

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of the invention according to claim 1.

FIG. 2 is a front view showing a part of the device in an enlarged manner.

FIG. 3 is a front view showing a second embodiment of the invention according to claim 1.

FIG. 4 is an enlarged front view showing an embodiment of the invention described in claim 2.

FIG. 5 is an enlarged front view showing a first embodiment of the invention according to claim 3;

FIG. 6 is a graph showing external transmittance of synthetic sapphire.

FIG. 7 is a graph showing external transmittance of silicon.

FIG. 8 is an enlarged front view showing a second embodiment of the invention according to claim 3;

FIG. 9 is an enlarged front view showing a first embodiment of the invention as set forth in claim 4;

FIG. 10 is an enlarged front view showing a second embodiment of the invention as set forth in claim 4;

FIG. 11 is a front view showing an embodiment of the invention as set forth in claim 5;

FIG. 12 is a front view showing an embodiment of the invention according to claim 6;

[Explanation of symbols]

 1 Recording Paper 4 Fixing Device 5 Heat Source 6 Heat Ray 7 Heat Ray Focusing Mirror 8 Blower Means 9 Solvent Vapor 10, 11 Heat Ray Transmitting Member 12, 13 Detection Sensor 14 Contact Heating Member 15 Negative Pressure Generating Means

Claims (6)

[Claims] 1. A wet image forming apparatus using a developing solution in which a toner is dissolved in a solvent, and a transfer device for transferring an image formed on a photoconductor onto a recording paper and this recording paper on which the image is transferred. A heat source and a heat ray focusing mirror for focusing and irradiating the heat ray radiated from the heat source toward the surface of the recording paper on which the image is transferred are provided between the fixing device for pressure fixing. Wet image forming apparatus. 2. The wet image forming apparatus according to claim 1, further comprising a blowing unit that blows air toward a spot where the heat rays are focused and irradiated by the heat ray focusing mirror. 3. The wet image forming apparatus according to claim 1, further comprising: a heat ray transmitting member that blocks the vaporized solvent vapor and transmits heat rays between the heat source and the recording paper. 4. A detection sensor for detecting that the recording paper is conveyed to a position upstream of a heat source along the recording paper conveyance direction, and a heat generation source is turned on / off based on a detection result from the detection sensor. The wet image forming apparatus according to claim 1, further comprising a control unit for controlling. 5. The wet image forming apparatus according to claim 1, further comprising a contact heating member provided between the transfer device and the fixing device to contact the back surface of the recording paper to heat the recording paper. 6. The wet image forming apparatus according to claim 5, further comprising negative pressure generating means for bringing the recording paper into suction contact with the contact heating member.