JP2000075773A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use water obtained from dehumidification in humidification in an image forming device by performing dehumidification without using extra energy. SOLUTION: A transfer material 50 is heated by a heating roller 78 to fix an image thereon. When the transfer material 50 is heated, moisture contained in the transfer material (paper) 50 vaporizes and steam is allowed to pass through a sling 86 and released into a closed space 87 surrounded by the heating roller 78 and a water droplet receiver 82, increasing humidity inside the closed space 87. The water droplet receiver 82 has a sufficiently lower temperature than the heating roller 78 so that when humidity inside the closed space 87 increases, the steam inside the closed space 87 condenses into water 98, which in turn clings to the inner surface of the water droplet receiver 82. The water 98 collecting on the bottom of the water droplet receiver 82 is collected into the catch pan of a humidifier and used for humidification. Since the moisture released from the transfer material 50 by the heat of fixing is utilized in humidification, no extra energy is needed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a fixing device for heating and fixing an image applied to a transfer material.

[0002]

2. Description of the Related Art A transfer material formed of a material that absorbs moisture, for example, paper (plain paper, tracing paper, etc.)
It is known that an image forming apparatus such as a copying machine, a printer, a plotter or the like which uses a printer causes an image defect due to the humidity of the sheet.

[0003] For this reason, there is an image forming apparatus provided with a dehumidifying device and a humidifying device, for example, an image forming device disclosed in Japanese Patent Application Laid-Open No. 9-81018.

[0004]

Problems to be Solved by the Invention Japanese Patent Application Laid-Open No. 9-81018
In the image forming apparatus disclosed in Japanese Patent Application Laid-Open Publication No. H10-209, the atmosphere in the apparatus is circulated, the water collected by dehumidifying the atmosphere is stored in a water storage tank, and this water is used for humidification.

[0005] However, since the dehumidification of the atmosphere in the apparatus is performed using a dehumidification heater dedicated to dehumidification, energy is required for dehumidification.

Further, since air is heated when a dehumidification heater is used, if the dehumidification is performed during high temperature and high humidity, the atmosphere in the apparatus may be heated to a high temperature.

Therefore, in order to generate humidifying water,
There is a problem that the energy of the heater for dehumidification is required and the temperature inside the device is increased.

[0008] Even if a well-known dehumidifying and humidifying mechanism is used, energy is still required for dehumidifying.

An object of the present invention is to provide an image forming apparatus which solves the above-mentioned conventional disadvantages in view of the above facts.

[0010]

According to an aspect of the present invention, there is provided an image forming apparatus, comprising: a fixing section for fixing a toner image transferred onto a transfer material; and the fixing section condensing water vapor radiated from the transfer material. And a humidifying unit for humidifying the inside of the apparatus housing using the water collected by the dehumidifying unit.

Next, the operation of the image forming apparatus according to the first aspect will be described.

In the image forming apparatus according to the first aspect, the transfer material onto which the toner image has been transferred is subjected to a fixing process in a fixing unit, and the toner image is fixed on the transfer material.

When the transfer material is a material containing water, for example, paper, when the fixing process is performed in the fixing unit, the water contained therein evaporates as water vapor.

The steam is recovered as water by the dehumidifying means.

The water collected by the dehumidifying means is used for humidifying means for humidifying the inside of the apparatus casing, and the humidifying means humidifies the inside of the apparatus casing using the water collected by the dehumidifying means.

As described above, in the image forming apparatus according to the first aspect, humidifying water can be obtained without requiring energy dedicated to dehumidification in the fixing step.

The water recovered by the dehumidifying means is
Since it is used as a part (or all) of the water used in the humidifying means, the time and effort for disposing of the water collected by the dehumidifying means can be greatly reduced, and the number of times of replenishing the water for humidification can be reduced to zero ( Or reduce).

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, a humidity sensor for measuring the humidity in the device housing and a humidity in the device housing detected by the humidity sensor are provided. And control means for operating the humidifying means based on the humidifying means.

Next, the operation of the image forming apparatus according to the second aspect will be described.

In the image forming apparatus according to the second aspect, the humidity sensor measures the humidity in the apparatus housing, and the control means operates the humidifying means based on the humidity in the apparatus housing detected by the humidity sensor, Humidification can be performed so that the humidity does not become lower than the humidity.

According to a third aspect of the present invention, in the image recording apparatus according to the first or second aspect, the fixing unit includes a heat roll whose outer peripheral surface is in contact with the transfer material and rotates. The dehumidifying unit is arranged to face the outer peripheral surface of the heat roll, sandwiches the transfer material between the heat roll and the heat roll, and allows water vapor emanating from the transfer material to permeate to a side opposite to the heat roll. It is characterized by having a water vapor permeable member, and a water droplet recovery member arranged on the side opposite to the heat roll side of the water vapor permeable member and condensing the water vapor of the water vapor transmitted through the water vapor permeable member.

Next, the operation of the image forming apparatus according to the third aspect will be described.

In the image forming apparatus according to the third aspect, the transfer material onto which the image has been transferred is transported while being sandwiched between the heat roll and the water vapor permeable member, and the toner image is fixed during this time. .

The water vapor emanating from the transfer material passes through the water vapor permeable member. The water vapor that has passed through the water vapor permeable member is
Water droplets come into contact with a water droplet collecting member (a temperature close to the ambient temperature in the device housing) having a lower temperature than the heat roll.

According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, the water vapor permeable member is a sheet-shaped mesh, and is arranged so as to contact along the outer peripheral surface of the heat roll. It is characterized by being established.

Next, the operation of the image forming apparatus according to the fourth aspect will be described.

In the image forming apparatus according to the fourth aspect, the water vapor diverged from the transfer material passes through the sheet-like mesh and enters the space. Since the water vapor permeable member is a sheet-shaped mesh, the water vapor can efficiently penetrate to efficiently generate humidifying water.

Note that the mesh may be a so-called woven fabric in which fibers are arranged in the course, or may be a mesh in which micropores are provided innumerably.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an image forming apparatus according to the present invention will be described with reference to FIGS.

As shown in FIG. 1, an image forming apparatus (a so-called copying machine) 10 according to the present embodiment includes an image transfer unit 13, a fixing unit 15, and a paper supply unit 16 in a substantially closed housing 11.
It has.

In the paper feed unit 16, four roll papers 18, 20, 22, and 24 as transfer materials can be set.

Which one of the roll papers 18 to 24 is to be used is set by an operator using a selection button provided on an operation panel (not shown).

One of the roll papers 18 to 24 is sent out by any of the feed rollers 26, 28, 30, 32, and is joined via a conveying path 34, 36, 38, 40 to a junction 42.
To be transported to

The roll paper 18 sent to the junction 42
24 is conveyed along a conveyance path 44, and is transferred to the image transfer unit 1 via a cutter unit 46 and a registration roller pair 48.
Conveyed to 3.

On the way, the leading end side of the roll paper 18 to 24 is cut into a predetermined length by the cutter 46 to become the transfer material 50.

The image transfer section 13 is provided with a photosensitive drum 14.

As shown in FIGS. 1 and 2, in the vicinity of the photosensitive drum 14, a charging section 52 for charging the drum surface is provided.
An image forming optical system 54 for projecting and exposing a document image (not shown) on the drum surface to form a latent image on the drum surface, a developing unit 56 for developing the latent image into a toner image, and transferring the toner image to the transfer material 50 A transfer unit 58 for transferring the image and a cleaner 63 for collecting unnecessary toner on the drum surface and cleaning the drum surface are arranged.

In the transfer section 58, a transfer corotron 60 and a peeling corotron 62 are arranged to face the photosensitive drum 14, respectively.

The transfer material 50 passes between the photosensitive drum 14 and the transfer coroton 60, and at this time, the transfer corotron 6
The toner image is transferred to the transfer material 50 by the zero discharge.

After the transfer material 50 onto which the toner image has been transferred is separated from the photosensitive drum 14 by the separating corotron 62, the toner remaining on the photosensitive drum 14 is collected by a cleaner 63 which is a toner cleaning device.

Transfer material 5 peeled off from photosensitive drum 14
0 is sent to the fixing unit 15 by the vacuum transfer device 64.

The vacuum transfer device 64 includes a vacuum fan 6
The transfer fan 50 is provided by the vacuum fan 66.
Are transported while being attracted to the transfer transport surface.

The transfer running surface is formed by conveying rollers 68, 70, 7
2 is formed by each peripheral surface.

The rotational force of a motor (not shown) is transmitted to the transport roller 68 via a belt 74. The rotational force of the transport roller 68 is further transmitted to the transport roller 70 via the belt 76, and the rotational force of the transport roller 70 is further transmitted to the roller 72 via the belt 77.

The fixing section 15 includes a heat roll 78 having a heater (not shown) therein.

As shown in FIGS. 2 to 4, below the heat roll 78, a water droplet collecting device 80 is disposed.

The water drop collecting device 80 includes a water drop collecting box 82 as a water drop collecting member having a substantially V-shaped cross section. The water drop collection box 82 is formed from a metal plate such as stainless steel.

A pressure plate 84 made of an elastic member such as a sponge is attached to the inner surface of the water drop collection box 82 near the upper end on the upstream side and near the upper end on the downstream side.

The opening of the water drop collecting box 82 is a glass cloth,
It is covered with a sling 86 as a flexible water vapor permeable member having excellent water vapor permeability such as a mesh.

The sling 86 is pressed against the heat roll 78 by the pressure plate 84,
Transfer material 50 passing in an arc shape between the transfer material 8 and the sling 86
Is a heat roll 78 rotated by a motor (not shown).
It is conveyed and heated while contacting the surface.

A substantially closed space 87 is formed between the heat roll 78 and the water drop collecting box 82.

The water drop collecting box 82 has a bottom part slightly inclined with respect to the horizontal direction, and one end of a hose 88 is connected to a lower end part as shown in FIG.

The other end of the hose 88 is inserted into a catch pan 92 of a humidifying device 90 as humidifying means, and water collected in the water drop collecting box 82 flows down to the catch pan 92 via the hose 88. ing.

One end of an overflow hose 94 is connected to the catch pan 92 near the upper end so that the collected water does not overflow.

The other end of the hose 94 is inserted into a collecting bottle 96, and water overflowing from the catch pan 92 is collected by the collecting bottle 96 via the hose 94.

In the present embodiment, the heat roll 78 and the water droplet collecting device 80 correspond to the dehumidifying means of the present invention.

Next, the operation of the present embodiment will be described.

First, a document image is projected and exposed by the imaging optical system 54 on the surface of the photosensitive drum 14 charged by the charging section 52, and a latent image is formed on the drum surface.

When the portion where the latent image is formed reaches the developing section 56, the latent image is developed to become a toner image. When the portion where the toner image is formed reaches the transfer portion 58, the toner image is transferred to the transfer material 5
Transferred to 0.

The transfer material 50 onto which the toner image has been transferred is transported to the fixing unit 15 by the vacuum transport device 64.

The transfer material 50 is heated by the heat roll 78, and the toner image is transferred to the transfer material 50.

Here, when the transfer material 50 is heated by the heat roll 78, the water contained in the transfer material (paper) 50 evaporates, and the warm water vapor passes through the mesh of the sling 86 and the heat roll 78 The air is discharged into the closed space 87 surrounded by the collection box 82, and the humidity in the closed space 87 increases.

The temperature of the water drop collection box 82 formed of a metal plate is close to the ambient temperature (room temperature + α) in the apparatus, that is, sufficiently lower than the heat roll 78 (for example, about 148 ° C.). When water vapor enters and the humidity of the closed space 87 increases, the water vapor in the closed space 87 condenses and water 98
And adheres to the inner surface of the water drop collection box 82.

Water 98 collected at the bottom of the water drop collection box 82
Is connected to the catch pan 9 of the humidifier 90 via a hose 88.
Run down to 2.

The water 98 collected in the catch pan 92
Can naturally evaporate and humidify the roll paper 18-24.

Therefore, when the humidity of the atmosphere in the apparatus is low, the evaporation of the water 98 accumulated in the catch pan 92 is promoted, and the roll papers 18 to 24 can be prevented from being excessively dried. On the other hand, when the humidity of the atmosphere in the apparatus is high, the water 98 accumulated in the catch pan 92 does not evaporate much, so that the water 98 accumulated in the catch pan 92 humidifies the roll paper 18 to 24 more than necessary. There is no.

Since the paper transfer material 50 always contains moisture, when heated by the heat roll 78, water vapor is surely generated from the transfer material 50. Further, in the present embodiment, unlike a fixing device of a type in which a transfer material is nipped and conveyed in a line contact state between a conventional heat roll and a nip roller, a sling 86 and a heat roll arranged so as to abut along the roll outer peripheral surface are provided. The transfer material 50 is in contact with the transfer material 50 in a rectangular shape (that is, the transfer material 50 is in contact for a longer time than the conventional type).

Therefore, in this embodiment, the transfer material 50
Most of the water evaporated from the water passes through the sling 86 and is discharged into a substantially closed space 87 surrounded by the heat roll 78 and the water drop collecting box 82, which can be recovered as water and used for humidification. There is an excellent effect that water can be reliably obtained from the transfer material 50.

In the present embodiment, the heat roll 78
And the water can be collected in the water drop collecting box 82 made of a metal plate, so that energy for dehumidification is not required as in the conventional case, the apparatus configuration is simple, and the apparatus is simpler than the conventional apparatus. Costs and running costs can be reduced.

When the water in the catch pan 92 is insufficient, the tap water can be directly supplied to the catch pan 92 in the first setting of the apparatus. A water level sensor or the like may be provided on the catch pan 92, and a warning may be displayed on an operation panel or the like when water for humidification runs short.

When water overflows from the catch pan 92, the collection bottle 9 is connected via a hose 94.
Collected in 6.

The water 98 collected in the collection bottle 96 can be used, for example, when the catch pan 92 runs short of water 98, and the collected water can be reused without being wasted.

The water 98 collected in the catch pan 92
In order to naturally evaporate, the catch pan 92 preferably has a large opening area. If the catch pan 92 has a small opening area such as a bottle, the evaporation of water is extremely slow, and the collected water cannot be used effectively for humidification.

In the present embodiment, the water drop collecting box 82 is formed of a metal plate such as stainless steel. However, the present invention is not limited to this, and has excellent heat conductivity, does not corrode due to water, and has an atmosphere in the apparatus. Any material other than the metal plate may be used as long as it is easy to adjust to the temperature, and the shape is not limited to the above embodiment.

In this embodiment, the opening of the water drop collecting box 82 is covered with a flexible sling 86 having excellent water vapor permeability such as glass cloth or mesh. However, the present invention is not limited to this. The material 86 is not particularly limited in material and structure as long as it has a certain degree of flexibility, is excellent in water vapor permeability, is resistant to abrasion, and has durability at a fixing temperature. Another Embodiment Next, another embodiment of the image forming apparatus of the present invention will be described with reference to FIG. The same components as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 5, in the present embodiment, one roll paper 100 as a transfer material is set in the paper feed unit 16, and the roll paper 100 is located on the downstream side in the transport direction of the roll paper 100. A heater 104 for evaporating excess moisture of the fed roll paper 100, that is, for dehumidifying the roll paper 100 is attached to the paper guide 102 to be arranged.

The catch pan 92 includes a catch pan 92.
The heater 106 for promoting the evaporation of the water accumulated in the heater is disposed.
08 is covered.

Further, a fan 110 for blowing air (arrow A) toward the catch pan 92 and circulating the air in the apparatus is arranged near the catch pan 92.

Further, a humidity sensor 112 for measuring the humidity of the atmosphere in the apparatus is arranged near the roll paper 100.

The above-described heater 104 and heater 10
6. The fan 110 and the humidity sensor 112
4, when the humidity of the atmosphere is too high during the rainy season or the like ((when the humidity is equal to or less than the preset second humidity, for example, the humidity is 60% or more (the present invention is not limited to this)).
In the case where the heater 104 is energized, excess moisture of the fed roll paper 100 is evaporated, and the humidity of the atmosphere is too low in winter or the like (below the first humidity set in advance, for example, 30% humidity). In the following case (the present invention is not limited to this), the heater 106 and the fan 110
And the evaporation of water in the catch pan 92 is promoted.

The evaporation may be promoted only by blowing air from the fan 110.

As described above, in this embodiment, the humidity can be automatically adjusted.

In this embodiment, the water is heated by the heater 106 for humidification. However, the present invention is not limited to this. For example, an ultrasonic vibration element (not shown) is provided in the catch pan 92. In addition, water can be atomized by the vibration of the ultrasonic vibration element, thereby humidifying the inside of the apparatus.

In the above embodiment, the present invention has been described by taking a copying machine as an example. However, the present invention transfers an image to a transfer material which may contain water and heats the image to fix the image. The present invention is applicable to all types of image forming apparatuses (for example, printers) that perform the following.

[0085]

As described above, in the image forming apparatus of the present invention, since the humidifying water is obtained from the steam generated at the time of fixing as described above, it is possible to eliminate the trouble of supplying the humidifying water. In addition, since it is not a method in which water obtained by a dehumidifier that uses electricity to dehumidify air as in a conventional image forming apparatus is used for humidification, an excellent effect that energy consumption can be reduced. Having.

Further, since a heater for heating the air for dehumidification is not used, there is an excellent effect that there is no possibility that the temperature in the apparatus becomes high.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram schematically showing an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of a part of a fixing unit and an image transfer unit.

FIG. 3 is a partial cross-sectional view of a fixing unit.

FIG. 4 is a perspective view showing a main part for performing dehumidification and humidification.

FIG. 5 is a side view of a main part of an image forming apparatus according to another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 image forming apparatus 11 housing (device housing) 15 fixing unit 18 roll paper (transfer material) 20 roll paper (transfer material) 22 roll paper (transfer material) 24 roll paper (transfer material) 78 heat roll 80 water droplet collecting device (Dehumidifying unit) 82 Water droplet collecting box (Water droplet collecting member) 86 Sling (Water vapor permeable member) 90 Humidifying device (Humidifying unit) 100 Roll paper (Transfer material)

Continued on the front page F term (reference) 2H027 DA14 ED25 ED30 JA15 JA16 JB02 JB03 JB19 JC08 JC12 JC13 2H033 AA16 AA33 AA39 BB00 CA11 CA35

Claims (4)

[Claims] A fixing unit for fixing the toner image transferred onto the transfer material; a dehumidifying unit configured to condense water vapor diverging from the transfer material by the fixing unit to generate water; An image forming apparatus, comprising: humidifying means for humidifying the inside of an apparatus housing using water. 2. A humidity sensor for measuring humidity in the device housing, and control means for operating the humidifying unit based on the humidity in the device housing detected by the humidity sensor. The image forming apparatus according to claim 1. 3. The fixing unit includes a heat roll that rotates while the outer peripheral surface thereof is in contact with the transfer material, and the dehumidifying unit is disposed so as to face the outer peripheral surface of the heat roll, and is disposed between the heat roll and the heat roll. While sandwiching the transfer material, a water vapor permeable member that transmits water vapor diverging from the transfer material to the side opposite to the heat roll side, disposed on the side opposite to the heat roll side of the water vapor permeable member, The image recording apparatus according to claim 1, further comprising: a water droplet collecting member configured to condense the moisture of the water vapor that has passed through the water vapor transmitting member. 4. The image forming apparatus according to claim 3, wherein the water vapor permeable member is a sheet-shaped mesh, and is disposed so as to contact along an outer peripheral surface of the heat roll. .