JP2003237964A - Paper feeder and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stable paper feeder that can hold a constant state of recording material in both high humidity and low humidity environments by a simple structure, and provide an image forming device that can produce a high quality image by holding a constant state of recording material in both high humidity and low humidity environments. <P>SOLUTION: A cassette 60 has a humidity control mechanism 100. When the interior of the cassette 60 is low in humidity, a humidity control material T absorbs moisture, a heater H heats the humidity control material T with a high moisture content, and air into which the humidity control material T emits moisture is fed into the cassette 60 to humidify the interior of the cassette 60. When the interior of the cassette 60 is high in humidity, the heater H heats the humidity control material T to release moisture, the air is released out, and substitutive dry air is fed into the cassette 60 to dehumidify the interior of the cassette 60. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device for feeding a recording material to another device, and an image forming apparatus for electrostatically forming an image on the recording material such as a copying machine and a laser beam printer. It is a thing.

[0002]

2. Description of the Related Art Conventionally, as an image forming apparatus such as a copying machine or a laser beam printer of this type, a toner image formed on an image bearing member such as a photosensitive drum is transferred to an intermediate transfer belt (intermediate transfer member). ), There is a four-color full-color copying machine in which a full-color image is formed by transferring the image onto a recording material such as paper all at once by transferring the image onto the recording material such as paper.

Particularly, among electrophotographic color image forming apparatuses, yellow,
Image forming units for each color of magenta, cyan and, if necessary, black are arranged linearly along the moving direction of the intermediate transfer belt (intermediate transfer member), and toner images of each color are formed almost simultaneously. Things are known.

[0004]

However, in the case of the above-mentioned prior art, the following problems have occurred. In the above-described full-color copying machine, since the electric charge is injected into the recording material, the water content of the recording material is a parameter that largely affects the image. In particular, when the recording material is so-called "paper", the components such as talc and kaolin contained therein absorb and release moisture so much that the physical properties such as resistance to environmental humidity change greatly.

Further, in the case of a full-color copying machine, four color toners have to be transferred, and a larger transfer current is required as compared with the case of transferring one color toner, and the image quality due to the variation of the resistance value. Will be noticeable. As a countermeasure against these adverse effects in a high humidity environment, for example, the recording material is set to have a temperature slightly higher than the installation environment temperature of the apparatus. That is, the water content inside the recording material is heated by a heating means such as a heater so that the water content does not exceed a certain level.

On the other hand, when the installation environment of the device is low humidity,
Although a method such as a water application roller or ultrasonic humidification has been proposed as a means for supplying moisture to the recording material in order to absorb the moisture in the recording material, a water supply means for compensating the moisture is required, which complicates the apparatus structure. However, there are problems such as complications of maintenance and maintenance, and there are few actual cases. Also,
There are some inventions such as arranging a hygroscopic material to cover the device, but even if it is a measure against sudden environmental temperature and humidity,
If the environment is always kept in a low humidity environment, there is a fatal defect that the effect does not come out.

The present invention has been made in order to solve the above-mentioned problems of the prior art. With a simple structure, the state of the recording material can be kept constant under both high humidity and low humidity environments. An object of the present invention is to provide a stable paper feeding device. It is another object of the present invention to provide an image forming apparatus capable of obtaining a high quality image by keeping the state of a recording material constant in both high humidity and low humidity environments.

[0008]

In order to achieve the above-mentioned object, the present invention is a paper feeding apparatus for feeding a recording material to another device, which has a cassette for accommodating the recording material therein. A humidity control mechanism that adjusts the amount of water in the recording material inside the cassette is provided with a humidity control material that absorbs and desorbs moisture according to the temperature.

By operating the humidity control mechanism having a simple structure, it is possible to provide a stable paper feeding device capable of keeping the state of the recording material constant in both high humidity and low humidity environments.

It is preferable that the humidity control mechanism includes the humidity control material and a heater that changes the temperature inside the humidity control mechanism for absorbing and releasing moisture. And, at least one side surface of the humidity control mechanism and an end portion facing the cassette are provided with a plurality of air passages for sending air to the humidity control material, and it is possible to switch the direction of the air sent to the humidity control material. desirable.

It is sufficient for the humidity control mechanism to prepare a humidity control material, a heater, and a plurality of switchable air passages. No equipment such as a water supply device for humidification is required, so maintenance is not required. The humidity of the recording material can be effectively controlled by a simple method that does not select the installation location.

In the case where the inside of the cassette has a high humidity, the humidity control material is dehumidified by the heating of the heater to release the air to the outside, and instead, the dried air is sent into the inside of the cassette, and It is desirable to dehumidify the inside of the cassette.

In the humidity control mechanism, a humidity control material made of a hygroscopic powder such as zeolite, silica gel, phosphorus oxide, magnesium chloride or the like is arranged, and the humidity control material is heated by the heater to remove moisture from the outside. To release. After that, dry air from the outside can be sent into the inside of the cassette to dehumidify the inside of the cassette to reduce the amount of water in the recording material and keep the amount of water in the recording material constant.

In the case where the inside of the cassette has low humidity, the humidity control material absorbs moisture to heat the humidity control material having an increased water content by the heater, and the humidity control material discharges water. It is preferable that the inside of the cassette is fed to humidify the inside of the cassette.

The humidity control material is arranged in the humidity control mechanism and external air is allowed to flow to the humidity control material. When the humidity control material is heated at a certain timing, the humidity control material discharges water, but at this time, the air passage is changed so that the air flow is directed toward the recording material. By repeating this operation, it is possible to increase the amount of water in the recording material and prevent image defects due to drying of the recording material when the humidity inside the apparatus is low.

It is preferable that a shutter which can be opened and closed is provided between the cassette and the humidity control mechanism, and the shutter shuts off both of them during the moisture absorption operation of the humidity control mechanism to seal the inside of the cassette. When the inside of the cassette is humidified and water is supplied by the humidity control mechanism, the hermeticity of the cassette is ensured by including the shutter,
It is possible to reduce the amount of water escaping from the inside of the cassette to the outside of the cassette during the moisture absorption operation of the humidity control mechanism.

An image forming section for forming an image on a recording material,
An image carrier for recording an image while traveling, having a cassette for accommodating and accommodating the recording material therein, and for feeding the recording material to the image forming unit,
The charging unit supplies an electric charge to the recording material, and the charging unit supplies the electric charge to the recording material to transfer the image on the image carrier onto the recording material, thereby forming the image on the recording material. An image forming apparatus for forming a sheet, the image forming apparatus including the sheet feeding device as described above in the sheet feeding means.

In the image forming apparatus provided with the paper feeding device having the above-mentioned means, the humidity control mechanism having a simple structure is made to function to keep the state of the recording material constant under both high humidity and low humidity environments. It became possible to obtain a high quality image by keeping it at.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes of the components described in this embodiment,
The relative arrangement, etc., unless otherwise specified,
The technical scope of the present invention is not intended to be limited thereto. Further, in the following drawings, the same reference numerals are given to the members described in the drawings used in the above description of the conventional art and the members similar to the members described in the above-mentioned drawings.

(Structure of Full Color Copying Machine) With reference to FIG. 1, a full color copying machine 1 according to the present embodiment will be described. FIG. 1 is a sectional view showing a schematic configuration of a full-color copying machine 1 according to this embodiment. Full color copier 1
As shown in FIG. 1, in the basic configuration of the above, an endless intermediate transfer belt 11 that runs in the arrow X direction is arranged in the main body of the full-color copying machine 1. This intermediate transfer belt 11 is
It is made of a dielectric resin such as polycarbonate, polyethylene terephthalate resin film, or polyvinylidene fluoride resin film. The recording material P taken out from the paper feeding cassette 60 by the paper feeding roller 114
Is supplied to the above-described intermediate transfer belt 11 via the registration roller 113, and is further conveyed to the left in the figure.

Above the intermediate transfer belt 11, four image forming portions 1a, 1b, 1c and 1d having substantially the same structure are arranged in series. The configuration of the image forming unit 1a will be described as an example. The image forming unit 1a includes a photosensitive drum 2a that is a rotatably arranged drum-shaped electrophotographic photosensitive member.
Around the photosensitive drum 2a, a primary charger 3a and a developing device 4 are provided.
Process devices such as a and cleaner 5a are arranged. The other image forming units 1b, 1c and 1d have the same structure as the image forming unit 1a, and in FIG.
Only b, 2c and 2d are shown.

The difference between the image forming sections 1a, 1b, 1c and 1d is that each forms a toner image of each color of magenta, cyan, yellow and black. Correspondingly, magenta toner, cyan toner, yellow toner, and black toner are stored in the developing devices arranged in the respective image forming units.

An image signal based on the magenta component color of the original is projected onto the photosensitive drum 2a via a polygon mirror (not shown) or the like to form an electrostatic latent image, on which magenta toner is supplied from the developing device. The electrostatic latent image becomes a magenta toner image. As the toner image is rotated by the photosensitive drum 2a,
When the photosensitive drum 2a and the intermediate transfer belt 11 come to the transfer site where they come into contact with each other, the first transfer bias applied by the first transfer member 112 causes the magenta toner image to be the intermediate transfer belt 11 which is an intermediate transfer member. Is transferred to.

When the intermediate transfer belt 11 carrying the magenta toner image is conveyed to the image forming section 1b, by this time, the cyan image formed on the photosensitive drum 2b in the image forming section 1b in the same manner as described above. The toner image is transferred onto the magenta toner image. Similarly, as the recording material P advances to the image forming portions 1c and 1d, the yellow toner image and the black toner image are superposed and transferred on the above-mentioned toner images at the respective transfer portions. At that time, the recording material P taken out from the cassette 60 reaches the transfer portion, and the above four color toner images are transferred onto the recording material P by the transfer bias applied to the transfer member 112. The recording material P is conveyed on the ejecting belt, separated by the separating unit 110, and conveyed to the fixing unit.

The fixing section has a step of fixing the toner on the recording material P by heat and pressure. Further, in order to improve the releasability between the recording material P and the fixing roller 111, a releasable oil (for example, silicone oil) is used.
1 has a mechanism for coating the surface, and this oil also adheres to the recording material P. Recording material P on which the toner image is fixed
Is discharged to the paper discharge tray, but when automatically forming a double-sided image, it passes through a recording material reverse path (not shown), is stored in the double-sided cassette, and is fed at the time of double-sided image formation. .

After that, the residual toner remaining on the photosensitive drum 1 is removed by the cleaner 5a, and the residual charge is removed by the pre-exposure means (not shown) so that the photosensitive drum is ready for the next image formation. Then, at the position downstream of the transfer portion of the intermediate transfer belt 11, the static eliminator 1
2. An intermediate transfer belt cleaning member 13 is provided to remove toner and the like adhering to the intermediate transfer belt 11.

(In Low Humidity Environment) The humidity control mechanism 100 according to the present embodiment will be described with reference to FIG. In the humidity control mechanism 100, a humidity control material T, for example, powder of zeolite, silica gel, phosphorus pentoxide, magnesium chloride is arranged in an upper portion inside the cassette 60. Then, in order to absorb and release the humidity of the humidity control material T, the heater H that changes the temperature inside the humidity control mechanism 100 is arranged. Furthermore, air passages A and B for sending air to the humidity control material T were provided. As shown in FIG. 2, the air passage A has a side surface of the humidity control mechanism 100 in contact with the outside of the full-color copying machine 1 as an intake port for taking in outside air, and the other side surface of the humidity control mechanism 100 which faces the air passage A ′ side. Is used as the exhaust port. On the other hand, the air passage B is provided at the end of the humidity control mechanism 100 that faces the cassette 60, and the direction of the air blown into the humidity control material T can be switched.

When the inside of the cassette 60 has low humidity, the humidity control material T absorbs moisture to increase the water content.
Is heated by the heater H, and the air whose moisture has been discharged by the humidity control material T is sent into the inside of the cassette 60 to humidify the inside of the cassette 60.

A humidity control material T is arranged in the humidity control mechanism 100 and external air is allowed to flow from the air passage A to the humidity control material T. When the humidity control material T is heated at a certain timing, the humidity control material T discharges water, but at this time, the air passage A-A 'is closed to block the flow of external air. After that, the air passage B is opened, and the air passage is changed so that the air flow from the heater H side to the recording material P is directed. By repeating this operation, it is possible to increase the water content of the recording material P and prevent image defects due to drying of the recording material P when the humidity in the apparatus is low.

Details of the above steps are shown in FIG.
In FIG. 2 (a), the air passage A-A 'is opened and the air passage B is closed. Outside air is flowing from the air passage A toward the air passage A ′. At that time, the moisture contained in the outside air is absorbed by the humidity control material T. Next, in FIG. 2B, the humidity control material T is heated by the heater H to release the absorbed moisture. Then, the air passage A-A 'is closed to block the air so that the moisture released by the humidity control material T does not escape to the outside of the humidity control mechanism 100. Figure 2
In (c), the air passage B is opened and the cassette 6 is inserted from the air passage B side.
By sending air in the direction of 0, the moisture released by the humidity control material T is sent into the cassette 60 to humidify the inside of the cassette 60 and supply the moisture to the recording material P. As a result, the water content of the recording material P increases. The above steps are appropriately repeated.

The point where the effect of the present invention is sufficiently exhibited is to improve the airtightness of the cassette 60 and to design the air passage. While the moisture of the outside air is stored in the humidity control material T, the moisture cannot be supplied in the recording material P direction. If the amount of moisture radiated from the cassette 60 is larger than the amount of moisture supplied to the recording material P during the moisture absorption operation, the sufficient effect cannot be obtained. It goes without saying that the tightness of the cassette becomes more important as the environment is extremely low humidity.

Therefore, as shown in FIG. 4, the cassette 60
Cassette 60 and humidity control mechanism 1 to improve the internal airtightness
A shutter 116 that can be opened and closed in the middle of 00 may be provided, and the shutter 116 may completely block the both during the moisture absorption operation of the humidity control mechanism 100 to seal the inside of the cassette 60. When the inside of the cassette 60 is humidified and water is supplied by the humidity control mechanism 100, the airtightness of the cassette 60 is ensured by providing the shutter 116.
It is possible to reduce the amount of moisture escaping from the inside of the cassette 60 to the outside of the cassette 60 during the moisture absorption operation of 0.

Further, in the design of the air passage, in the step of humidifying the recording material P according to the present invention, it is difficult for the humidity adjusting material T to absorb moisture of the outside air again unless the humidity adjusting material T that has been heated is sufficiently cooled. There are also challenges. After the humidity control material finishes the moisture releasing operation, the external air is sent to the humidity control material T at a wind speed such that the humidity control material T cools quickly, and the heat source arranged on the upper part is used more than necessary. It is important not to get close.

(In case of high humidity environment) The present invention is also effective in the dehumidification process of the recording material P in the high humidity environment. That is, conventionally, the recording material P was dehumidified by warming the recording material P itself, but by switching the air path with the humidity control material T, the moisture inside the cassette 60 is discharged to the outside of the cassette 60. Because it acts like a pump,
A small amount of heat is required to dehydrate the recording material P.

When the inside of the cassette 60 has a high humidity, the humidity of the humidity control material T is released by the heating of the heater H and the air is discharged to the outside, and the dry air is sent into the inside of the cassette 60 instead. The inside of the cassette 60 is dehumidified.

The humidity control material T is heated by the heater H to release moisture to the outside. After that, dry air from the outside can be sent into the inside of the cassette 60 to dehumidify the inside of the cassette 60 to reduce the water content of the recording material P and keep the water content of the recording material P constant.

Particularly in the case of the conventional type in which the recording material P is directly heated, when the recording material P inside the cassette 60 is small, the recording material P is overheated and the cassette 6
Since the amount of heat released from the heater H for heating 0 is large,
The recording material P and the heater H carried into the machine during image formation
However, according to the present invention, the heating amount of the recording material P can be significantly reduced as compared with the conventional method. This point is also very effective.

Further, in the case of the heating system of the recording material, in order to improve the efficiency, not only the hermeticity of the cassette 60 needs to be improved, but also the heat insulation must be performed, so that the humidity inside the cassette 60 can be lowered also in this respect. The present invention is advantageous in improving the effect of sealing. To change the air path, take the steps opposite to those when the humidity is low. The steps are shown in FIG.

In FIG. 3A, the humidity control material T is heated by the heater H to release the moisture stored in the humidity control material T. At this time, the air passage B is closed and the air passage A-A 'is opened to discharge the moisture released from the humidity control material T from the air passage air passage A'to the outside of the humidity control mechanism 100. Then, in FIG. 3B, the air passage A-A ′ is closed, the air passage B is opened, and the dry air outside the humidity control mechanism 100 heated by the heat of the heater H is sent into the cassette 60. The recording material P is dehumidified by the air. Further, in FIG. 3, the humidity control material T that has released the moisture in FIG. 3A absorbs the moisture of the dehumidified recording material P. The above steps are appropriately repeated to dehumidify the inside of the cassette 60.

Originally, in order to dehumidify the recording material P, it is more effective to arrange the humidity control material T in the lower part of the cassette 60. Therefore, the humidity control material T is arranged in such a region especially in a high humidity environment. It is better to do this, but in areas where the humidity is high in the summer and low in the winter, humidification in a low-humidity environment requires higher performance as the humidity control ability.
In order to achieve both, it is more effective to dispose the humidity control material T on the upper portion of the cassette 60.

As described above, in a high humidity environment, it is possible to dehumidify the recording material T with a smaller amount of heat required than by heating the conventional recording material P. That is, by using the present invention, the cassette 60 can be used from low humidity environments to high humidity environments.
The state of the internal recording material can be kept relatively constant, and better image quality can be kept.

Further, the humidity control mechanism 100 only needs to prepare a humidity control material T, a heater H, and switchable air passages A and B, and there is no need for equipment such as a water supply device for humidification. Is unnecessary, and the humidity of the recording material P can be effectively controlled by a simple method that does not select an installation place.

In this embodiment, the full-color copying machine 1 is taken as an example of the image forming apparatus, but the present invention is not limited to this, and a paper feeding device such as a printer, a fax machine or a monochrome copying machine is provided. It can be applied to things.

As the image forming means, electrophotographic image forming means, ink jet type image forming means and the like can be applied, but the image forming means is not limited to these.
A thermal transfer recording system, a thermal recording system, and further a wire dot can be applied.

[0045]

As described above, according to the present invention, the sheet feeding device having the cassette for accommodating and accommodating the recording material therein and feeding the recording material to another device absorbs and discharges the recording material according to the temperature. A humidity control mechanism that adjusts the water content of the recording material inside the cassette is provided by a humidity control material that damps the humidity, so the recording material can be kept in a constant state in both high and low humidity environments with a simple configuration. It is possible to provide a stable paper feeding device that can be maintained. Further, it is possible to provide an image forming apparatus capable of obtaining a high quality image by keeping the state of the recording material constant in both high humidity and low humidity environments.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of a full-color copying machine according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a paper feed cassette according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a paper feed cassette according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a sheet feeding cassette according to the exemplary embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a schematic configuration of a conventional full-color copying machine.

[Explanation of symbols]

1 Full color copier 1a Image forming unit 1b Image forming unit 1c Image forming section 1d Image forming section 2a Photosensitive drum 2b photosensitive drum 2c photosensitive drum 2d photosensitive drum 3a Primary charger 4a Developing device 5a cleaner 60 cassettes 11 Intermediate transfer belt 12 Antistatic charger 13 Intermediate transfer belt cleaning member 100 humidity control mechanism 110 Separation part 111 fixing roller 112 Transfer member 113 Registration roller 114 paper feed roller 116 shutter A wind path B wind path H heater P recording material T humidity control material

Claims (9)

[Claims] 1. A paper feeding device for feeding a recording material to another device, comprising a cassette for accommodating and accommodating the recording material therein, wherein the cassette is provided by a humidity control material that absorbs and desorbs moisture according to temperature. A paper feeder equipped with a humidity control mechanism that adjusts the amount of water in the recording material inside. 2. The supply according to claim 1, wherein the humidity control mechanism includes the humidity control material and a heater that changes a temperature inside the humidity control mechanism for absorbing and releasing moisture. Paper equipment. 3. A plurality of air passages for sending air to the humidity control material are provided at at least one side surface of the humidity control mechanism and an end portion facing the cassette, and the direction of the air sent to the humidity control material can be switched. The sheet feeding device according to claim 2, wherein the sheet feeding device is provided. 4. When the inside of the cassette has a high humidity, the humidity of the humidity control material is released by the heating of the heater to release the air to the outside, and instead the dry air is sent to the inside of the cassette. The sheet feeding device according to claim 2, wherein the inside of the cassette is dehumidified by. 5. The paper feeding device according to claim 4, wherein the humidity control mechanism is attached to a lower portion of the cassette. 6. When the inside of the cassette has a low humidity, the humidity control material absorbs moisture to heat the humidity control material having an increased water content by the heater, and the humidity control material discharges the water content. The humidified air is fed into the cassette to humidify the inside of the cassette.
The paper feeder described in. 7. A shutter which can be opened and closed is provided between the cassette and the humidity control mechanism, and the shutter shuts off both of them during the moisture absorption operation of the humidity control mechanism to seal the inside of the cassette. The sheet feeding device according to claim 6. 8. The sheet feeding device according to claim 1, wherein the humidity control mechanism is mounted on the upper portion of the cassette. 9. An image forming unit for forming an image on a recording material, a cassette for accommodating and accommodating the recording material therein, and a paper feed for feeding the recording material to the image forming unit, The image forming unit has an image carrier for recording an image while running, and a charging unit for supplying an electric charge to the recording material. An image forming apparatus for forming an image on a recording material by transferring the image of claim 1 onto a recording material, the image comprising the paper feeding device according to claim 1 in the paper feeding means. Forming equipment.