JP3415910B2 - Paper storage device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet storage device having a sheet tray, such as an electrophotographic copying machine. 2. Description of the Related Art In an image forming apparatus such as an electrophotographic copying machine, a plurality of paper feed trays are mounted at a lower portion of an apparatus main body to constitute a paper feeder. Paper of an arbitrary size can be sent out of paper of different sizes stored in a paper tray. Further, in a general image forming apparatus, when a toner image formed on an image carrier such as a photosensitive drum is transferred onto a sheet, it is known that moisture contained in the sheet greatly affects the transfer. For example, if the water content of the paper is high, the transfer operation of the toner image is not performed in a good state, and white spots or the like of the image occur, leading to a problem that the quality of the copy deteriorates. Also, if the water content of the paper is locally large, the paper may have a wavy state, and if heated when passing through the fixing device, the paper will have a pronounced wavy state,
In addition to the problem that the appearance of the copy is not good, it causes a jam and a transfer failure of an image when the paper is conveyed in the paper conveyance path. [0003] In order to solve the above-mentioned problem of paper containing water, a heating means is arranged inside the paper feed unit or the paper feed tray to adjust the humidity of the paper. I have. For example, in an example disclosed in Japanese Patent Application Laid-Open No. 3-179465, a heater is provided between a photosensitive drum and a sheet feeding tray of an image forming apparatus, and a temperature and humidity are detected inside the apparatus. The sensor which performs it is arranged. Then, heating by a heater is performed in accordance with the detection information of the temperature or humidity inside the apparatus, and the function of dehumidifying inside the apparatus can be performed. In the example disclosed in JP-A-3-102075, a heater and a fan are arranged in combination with a sheet feeding tray, and a sensor is arranged with respect to the sheet feeding tray. Then, a mechanism is configured to operate the heater and the fan to dehumidify the sheet according to the difference between the temperature in the sheet feed tray and the reference temperature. Further, in the example disclosed in Japanese Patent Application Laid-Open No. Sho 61-282857, the temperature inside the image forming apparatus main body is kept constant, and the heat generated from the image forming member and the fixing device is transferred to the outside of the apparatus. This constitutes a means for adjusting the discharging operation so as to keep the internal temperature constant. Then, by arranging the dehumidifying means as described above in the paper feeding unit, the state of the humidity of the paper sent toward the image transfer unit of the image forming apparatus is adjusted, and the defective copy due to the high water content of the paper is adjusted. It is possible to prevent occurrence. In addition to the above-described conventional example, a paper feeder 10 is arranged at a lower portion of a main body of an image forming apparatus 1 such as an electrophotographic copying machine shown in FIG. A means for performing dehumidification using a heater 15 provided below the trays 11, 11a, 11b is performed. Means for forming a toner image on the photosensitive drum 5 by using an electrophotographic method and means for transferring the toner image to a sheet are arranged at an upper portion of the apparatus main body of the image forming apparatus. Then, an image from the photosensitive drum is transferred from a tray arranged in the paper feeding device 10 to a paper fed through the paper transport path 8, and the paper is fixed through the fixing device 6 to form a copy. A mechanism for discharging objects toward the discharge tray 7 is configured. In the image forming apparatus 1, sheets of different sizes are stored in a plurality of paper feed trays arranged in the paper feeder 10, as in a general electrophotographic copying machine. According to the information such as the size of the document and the enlargement / reduction ratio, a sheet of a corresponding size can be sent out to the image recording unit. In the image forming apparatus, the internal devices are hermetically sealed by the frames 2 and 2a and the outer cover member, the upper partition member 3 of the sheet feeding device 10 and the main body lower frame 4 arranged below. ing. In addition, a heater 15 is arranged below the sheet feeding unit to constitute a means for heating the inside of the sheet feeding device, and a dehumidifying effect on the sheet is performed by using information of a humidity sensor arranged inside. can do. However, when the dehumidifying means as shown in FIG. 5 is constructed, it is necessary to provide a heater having a relatively large heat generation, and the power consumption of the image forming apparatus is reduced. In order to solve the problem of affecting the power supply, it is necessary to control the energization timing of the heater and the like in accordance with the operation of other devices. Further, when a paper dehumidifying unit as shown in the conventional example is used, for example, as shown in the above-mentioned Japanese Patent Application Laid-Open No. 3-179465, when a heater is provided inside the apparatus main body to heat the entire apparatus. May have a thermal effect on the toner,
Problems such as deterioration in image quality are likely to occur. Further, even if the entire atmosphere is kept at a high temperature, there remains a problem that the dehumidifying action on the paper cannot be performed in a favorable state. Further, in the apparatus disclosed in Japanese Patent Application Laid-Open No. HEI 3-102075, the heater and the fan are operated even in an environment that does not require dehumidification such as low temperature and low humidity, so that unnecessary power is consumed. is there. When the heater and the fan are operated in a low humidity state, an excessive drying action is applied to the sheet, so that the sheet may be curled or wavy, or the image may be transferred to the sheet having a low water content. Trouble occurs. In addition to the above conventional example, Japanese Patent Application Laid-Open No. 61-2828
In the example disclosed in JP-A-57-57, there is a problem that accurate humidity control cannot be performed because a means for detecting the humidity inside the apparatus main body is not used. In addition, when the atmosphere outside the apparatus is in a high-temperature and high-humidity state, it is difficult to exert a dehumidifying effect only by exhausting with a fan, and it is difficult to sufficiently exert a dehumidifying effect on paper stored in the apparatus. is there. Therefore, as described above, in the conventional dehumidifying apparatus, there remain problems such as local strong heating of the sheet and the dehumidifying action not being sufficiently exhibited. In addition, in the conventional dehumidifier, even when the external humidity is low, there is a problem that the heater or the like is operated to heat the paper and the electric power is wastefully used. At present, development of a device capable of efficiently performing a dehumidifying operation is awaited. SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problem of humidity control in a conventional paper storage device. The present invention uses two sensors for detecting the humidity inside and outside the paper feeding unit. It is an object to provide an efficient device by providing a means for detecting a difference in humidity between the above and a fan for taking in outside air. [0010] The present invention relates to an image forming apparatus. In the present invention, a sheet feeding device having a tray for storing sheets, first detecting means for detecting humidity in the sheet feeding device, and a second detecting device for detecting humidity of outside air outside the sheet feeding device. 2, a fan provided on the side of the paper feeding device and for taking in outside air into the paper feeding device, a heater provided below the paper feeding device and heating the inside of the paper feeding device, A control device that operates the fan and the heater in accordance with the detection information of the first detection unit and the second detection unit to control the internal humidity in the sheet feeding device to be equal to or less than a set value; The device is characterized in that when the humidity of the outside air is lower than the set value, the outside air is introduced into the device by the fan, and when the humidity of the outside air is higher than the set value, the heater is operated. As described above, in the present invention, a humidity sensor is disposed inside and outside of a sheet feeding unit accommodating one or a plurality of sheet feeding trays, and information of the two sensors is controlled. Input to the device to compare the inside and outside humidity.
In addition, a heater and a fan are arranged in the paper feeding unit, and when the humidity of the outside air is lower than that of the inside, the outside air is introduced into the machine to maintain the inside atmosphere at a low humidity, thereby performing dehumidification of the paper. It can be so. Further, when the inside and outside humidity are high, the heater is operated to heat the inside, thereby enabling the paper to be dehumidified. Therefore, when the heater and the fan are arranged for the sheet feeding unit, the dehumidifying unit can be appropriately operated according to the difference in humidity between the inside and the outside.
In addition to the above configuration, the paper storage device of the present invention can be provided with only a fan. By adjusting the temperature and humidity inside the paper storage device without excessively drying the paper due to the heat of the heating member, it is possible to prevent the local unevenness of moisture from being generated in the paper and improve the recording quality. It can be maintained in a state. DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus of the present invention will be described with reference to the illustrated example. In the example shown in FIG. 1, a paper feeder 1
0, and a plurality of paper feed trays are arranged in the paper feeder 10 as in the case of FIG. Further, a unit for forming a toner image on the photosensitive drum by using an electrophotographic method and a unit for transferring the toner image to a sheet can be arranged at an upper portion of the apparatus main body of the image forming apparatus.
In the example shown in FIG. 1, the configuration of the main body of the image forming apparatus and the like is omitted, and the configuration of the heater 15 and the fan 17 disposed with respect to the sheet feeding device 10 and the configuration of the control unit is shown. I have. In the paper feeder 10, as described above,
A plurality of paper feed trays 11 are provided and a mechanism for feeding paper toward the image transfer unit is provided. In addition, a humidity sensor S1 as first detection means is provided inside the paper feed device 10.
And a sensor S2 as second detection means is disposed outside the sheet feeding device to detect the humidity of the outside air. In addition, a heater 15 is disposed at a lower portion of the paper feeding device 10, and a fan 17 for taking in outside air is provided at a side portion. Each device is connected to a power supply circuit (not shown), A mechanism is configured to be driven via control circuits 21 and 22 in accordance with the control information from 20. The control of the heater and the fan is performed by inputting information of the two sensors S1 and S2 to the control device 20 and operating necessary devices according to a difference in humidity between the inside and outside of the sheet feeding device.
It is possible to perform a dehumidifying action on paper stored in a paper storage device of a paper feeding unit. In the apparatus shown in FIG. 1, the control operation shown in the flowchart of FIG. 2 is performed according to the information of the two sensors. In the example shown in the flowchart of FIG. 2, when a start signal of the apparatus is input, a humidity signal of the sensor is input in steps a-1 and a-2, and two pieces of information are compared in step a-3. , S
If 1 <S2, the process proceeds to step a-4 to compare the internal humidity with the humidity S set in the control device. Then, when the internal humidity is lower than the set humidity, the mode shifts to the paper-feedable mode without operating both the heater and the fan. In step a-3, S1 ≧
In the case of S2, the process proceeds to step b-1 to compare the humidity of the outside air with the set humidity. If the humidity of the outside air is lower than the set humidity, the process proceeds to step b-2 to drive the fan. A signal is output and outside air is introduced into the machine by a fan. Then, during the driving of the fan, the set humidity S is compared with the humidity S1 in the machine at any time (step b-3), and the driving of the fan is stopped when S1 ≦ S. If the humidity of the outside air is higher than the set humidity in the step b-1, since the effect is small even if the outside air is introduced, the process proceeds to the step a-4 and S1 ≧
In the case of S, the process proceeds to step a-5, in which the heater is operated to heat the inside. While the heater is being heated in the step a-5, the sensor S1
Is compared with the set humidity S (step a-6). When the humidity in the apparatus is equal to or lower than the set humidity, the power supply to the heater is turned off in step a-7, and the operation of the humidity adjustment is completed. I do. Therefore, when a heater and a fan are arranged in the paper feeding device 10 as shown in FIG. 1, a more efficient dehumidifying operation can be performed by using information on the humidity inside and outside the paper feeding device. Can be done. In addition,
In steps a-3 and b-1 of the flowchart, in a state where the external humidity S2 is lower than the internal humidity and higher than the set temperature S, the fan is driven to introduce the outside air into the machine, and then a-5. When the heating is performed by the heater after shifting to the step, the power consumed by the heater can be reduced, and the heating operation can be performed efficiently. In the present invention, in addition to the apparatus shown in FIG. 1, a fan 17 for introducing only outside air to the sheet feeding device 10 can be arranged as shown in FIG. The image forming apparatus using the paper feeding device 10 can be used, for example, in an area where the humidity of the outside air is always lower than a set humidity, or in an office where the environment is well maintained. Then, when the humidity inside the apparatus is higher than the outside air, the outside air is introduced using the fan 17 to adjust the humidity inside the sheet feeding device, so that the sheet can be dehumidified and the sheet humidity distribution can be made uniform. . In the sheet feeding device of FIG. 3, the fan is operated only when the internal humidity is high, and when the humidity of the outside air is high, the fan is kept stopped and output from each device of the image forming apparatus. It is possible to perform the dehumidification of the paper using the heat generated. In addition to the paper feeding device, in the present invention, as shown in FIG.
5, a mechanism for performing a dehumidifying action inside the sheet feeding device can be configured. In the example shown in FIG. 4, information from the two sensors is input to the control device 20, and when the internal humidity is high, a drive signal for the heater is output via the control circuit 21 to perform the operation of dehumidifying the paper. Can be performed efficiently. In the paper feeder of the present invention configured as described above, two humidity sensors S1 and S2 are disposed inside and outside the paper feeder, respectively, and the humidity information from these sensors is obtained.
The humidity is input to the control device 20 to compare the humidity inside and outside the device. The two members, the heater and the fan, can be appropriately operated according to the information on the humidity inside and outside the device. Further, in the heater arranged in the sheet feeding device of the present invention, an arbitrary heating member can be used. In particular, when the heater is formed of a plate-like thin member, the heater is disposed below the sheet feeding tray. The space for the heater to be arranged can be reduced, and the overall configuration of the sheet feeding device can be reduced in size. Further, as the sensors disposed inside and outside the sheet feeding device of the present invention, sensors used for general humidity detection can be used. By using a temperature sensor in combination with the sensor and inputting information of humidity and temperature to the control device, it is possible to control the moisture content of the paper. According to the apparatus of the present invention, as described above, a humidity sensor is disposed inside and outside a paper storage device that stores one or a plurality of paper feed trays. Information is input to the control unit to compare the inside and outside humidity, and a heater and a fan are arranged.If the humidity of the outside air is lower than the inside, the outside air is introduced into the machine to maintain the inside atmosphere at low humidity As a result, the paper can be dehumidified. When the inside and outside humidity are high, the heater can be operated to heat the inside and dehumidify the paper. Therefore, when the heater and the fan are arranged for the sheet feeding unit, the dehumidifying unit can be appropriately operated according to the difference in humidity between the inside and the outside. Further, when the paper storage device of the present invention is provided with only a fan, the heating member adjusts the humidity inside the paper storage device without excessively drying the paper, so that the paper can be locally applied to the paper. It is possible to prevent the occurrence of uneven humidity, and to maintain the quality of recording in a good state without causing white spots or the like in an image.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing a configuration of a dehumidifying device of a sheet feeding device of the present invention. FIG. 2 is a flowchart showing the operation of the dehumidifier of the present invention. FIG. 3 is an explanatory diagram of a second embodiment of the present invention. FIG. 4 is an explanatory diagram of a third embodiment of the present invention. FIG. 5 is an explanatory diagram of a conventional dehumidifier. [Description of Signs] 1 Image forming apparatus, 10 Paper feeder, 15
Heater, 17 fan, 20 controller, 21
* 22 control circuit.

Continuation of front page       (56) References JP-A-5-19581 (JP, A)                 JP-A-57-189148 (JP, A)                 JP-A-61-282857 (JP, A)                 JP-A-56-80061 (JP, A)

Claims (1)

(57) [Claim 1] An image forming apparatus, comprising: a paper feeder having a tray for storing paper; and a first detection for detecting humidity in the paper feeder. Means, a second detecting means for detecting the humidity of the outside air outside the paper feeding device, a fan provided on the side of the paper feeding device, and taking in the outside air into the paper feeding device, a lower portion of the paper feeding device And a heater for heating the inside of the sheet feeding device; and operating the fan and the heater in accordance with the detection information of the first detection unit and the second detection unit to thereby operate the inside of the sheet feeding device. A controller that controls the humidity to be equal to or less than a set value, wherein the controller introduces the outside air into the device by the fan when the humidity of the outside air is lower than the set value, and sets the humidity of the outside air to the setting. If the value is higher than the value, the heater is operated. Characteristic image forming apparatus.