JP5184449B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  In recent years, image forming apparatuses have been rapidly spread in offices and homes as scanners, copiers, printers, facsimiles, digital multifunction peripherals, and the like. In such an image forming apparatus, the image formed in the image forming unit is transferred to the sheet material conveyed from the paper feeding device, and the sheet material to which the image is transferred is heated by the fixing device to fix the image. I am letting.

  In such a heating type fixing device, the image transferred to the sheet material is fixed to the sheet material by pressurizing and heating. For this reason, the sheet material immediately after fixing becomes a high temperature exceeding 100 ° C., and moisture contained in the sheet material is released as water vapor. The water vapor is condensed by touching the surrounding parts having a low temperature to form water droplets. When the water droplets adhere to the sheet material, a conveyance failure such as a paper jam or an image defect due to bleeding occurs.

  Various techniques for solving such a problem have been studied. For example, in Patent Document 1, a conveyance path between a fixing device and a discharge roll is formed by a guide plate provided with a heating element. A structure in which a temperature sensor is provided in the vicinity is disclosed. Accordingly, the heating element is appropriately energized and heated to appropriately control so as not to cause a temperature difference in the air in the conveyance path, thereby preventing the occurrence of condensation.

  Patent Document 2 discloses a structure in which a clamping unit is provided so as to close a sheet material discharge port of a container of a fixing device. Thus, water vapor generated in the container is prevented from flowing out of the container through the sheet material discharge port, and the occurrence of dew condensation outside the fixing device is suppressed.

JP-A-4-166968 JP 2007-86509 A

In the techniques of Patent Documents 1 and 2, it is considered that an image forming apparatus capable of preventing the occurrence of dew condensation can be obtained, but there are problems as follows.
In Patent Document 1, since dew condensation is prevented by heating, there is a concern about increase in power consumption and decrease in durability due to extension of warm-up time. In Patent Document 2, condensation is prevented by increasing the airtightness in the container of the fixing device, but it is difficult to increase the airtightness to a level at which water vapor does not flow out of the container of the fixing device.

  The present invention has been made in view of the above-described problems, and provides an image forming apparatus capable of reducing power consumption, suppressing deterioration in durability, and preventing occurrence of problems due to moisture adhering to a sheet material. The purpose is to provide.

  In order to solve the above-described problems, the present invention provides a fixing device that fixes toner on a sheet material, a conveyance roll that conveys the sheet material on which the toner is fixed, and a peripheral surface of the conveyance roll. And a brush that scrapes off moisture adhering to the surface of the transport roll.

  By adopting such a configuration, in the present invention, the brush is slidably contacted with the surface of the transport roll to scrape off the water adhering to the surface of the transport roll. Occurrence of problems due to adhesion to the material is prevented. Moreover, since it is not the structure which prevents dew condensation by heating like patent document 1, it can aim at low power consumption and can suppress the fall of durability. Therefore, it is possible to provide an image forming apparatus capable of reducing power consumption, suppressing a decrease in durability, and preventing occurrence of problems due to moisture adhering to the sheet material.

  Moreover, in this invention, the structure that the groove | channel parallel to the rotating shaft of the said conveyance roll is formed in the part which contact | connects the said brush on the surrounding surface of the said conveyance roll is employ | adopted.

  Moreover, in this invention, the structure that the said brush is pressed so that it may bite into the groove | channel of the said conveyance roll is employ | adopted.

  Moreover, in this invention, the said conveyance roll employ | adopts the structure that it is formed with the silicon rubber.

  Moreover, in this invention, the structure that the shape of the part which contact | connects the said conveyance roll of the said brush becomes uneven | corrugated shape wavy along the rotating shaft direction of the said conveyance roll is employ | adopted.

According to the present invention, a fixing device that fixes toner on a sheet material, a conveyance roll that conveys the sheet material on which the toner is fixed, and a sliding surface that contacts the peripheral surface of the conveyance roll and adheres to the surface of the conveyance roll. By adopting the configuration of having a brush that scrapes off the moisture that has been removed, the brush adheres to the surface of the transport roll by scraping the moisture that has adhered to the surface of the transport roll, so that the moisture generated by condensation is removed. The occurrence of problems due to moisture adhering to the sheet material is prevented. Moreover, since it is not the structure which prevents dew condensation by heating like patent document 1, it can aim at low power consumption and can suppress the fall of durability.
Therefore, according to the present invention, it is possible to provide an image forming apparatus that can reduce power consumption, suppress a decrease in durability, and prevent occurrence of problems due to moisture adhering to the sheet material.

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus of the present invention. It is the A section enlarged view of FIG. It is a perspective view which shows the arrangement | positioning relationship between a conveyance roll and a brush. It is a perspective view of a conveyance roll. It is a front view of the brush of the other form of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. This embodiment shows one aspect of the present invention, and does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structure easy to understand, an actual structure and a scale, a number, and the like in each structure are different.

  FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus 1 of the present invention. FIG. 2 is an enlarged view of part A in FIG. FIG. 1 is a diagram showing a peripheral structure of a fixing device 20 that heats and fixes toner transferred onto a sheet material onto the sheet material. FIG. 2 is a view showing the peripheral structure of the transport rolls 23 and 24 for transporting the sheet material on which the toner is fixed.

  As shown in FIG. 1, the fixing device 20 includes a heating roll 21 provided with a heater inside, and a press-contacting roll 22 pressed against the heating roll 21. The fixing device 20 has a function of fixing the toner onto the sheet material by sandwiching and conveying the sheet material onto which the toner has been transferred by the two rolls 21 and 22 to heat and press the sheet material. The sheet material on which the toner is fixed by the fixing device 20 is conveyed along the conveyance path L, and is discharged from the discharge port 40 via the pair of conveyance rolls 23 and 24 and the pair of discharge rolls 25 and 26. .

  By the way, the fixing device 20 of the present embodiment employs a heating method in which an image transferred to a sheet material is pressed and heated to be fixed on the sheet material. For this reason, the sheet material immediately after fixing becomes a high temperature exceeding 100 ° C., and moisture contained in the sheet material is released as water vapor. This water vapor may be condensed by touching the surrounding parts with low temperature to form water droplets. When the water droplets generated at this time adhere to the sheet material, a conveyance failure such as a paper jam or an image defect due to bleeding occurs.

  Therefore, in the present embodiment, a brush 30 that is in sliding contact with a transport roll 24 that transports the sheet material on which the toner is fixed by the fixing device 20 is provided. As the brush 30, for example, a carbon brush or a nylon brush can be used, and the brush 30 is not limited to this as long as it is in sliding contact with the surface of the transport roll 24. In the present embodiment, a carbon brush having a density of 19100 F / inch is used as the brush 30. The brush 30 has a function of sliding on the surface of the transport roll 24 and scraping off moisture adhering to the surface of the transport roll 24.

  With such a configuration, the moisture adhering to the surface of the transport roll 24 is scraped off by the brush 30, so that the occurrence of problems due to the moisture adhering to the sheet material is prevented by removing the moisture generated by condensation. Moreover, since it is not the structure which prevents dew condensation by heating like patent document 1, it can aim at low power consumption and can suppress the fall of durability.

  As shown in FIG. 2, a plurality of grooves 24 a are formed in a portion in contact with the brush 30 on the peripheral surface of the transport roll 24. The brush 30 is pressed so as to bite into the groove 24 a of the transport roll 24. For example, the brush 30 is pressed against the transport roll 24 so that the tip of the brush bites into 1 to 2 mm.

  As a material for forming the transport roll 24, for example, a rubber-based material such as metal, plastic, silicon rubber, or the like can be used. In the present embodiment, a rubber-based material such as silicon rubber is used as a material for forming the transport roll 24. Since the conveyance roll 24 is formed of silicon rubber, it has flexibility, so that the brush 30 can easily bite into the groove 24 a of the conveyance roll 24.

  FIG. 3 is a perspective view showing an arrangement relationship between the transport roll and the brush. In FIG. 3, the symbol W <b> 1 indicates the width of the transport roll 24, and the symbol W <b> 2 indicates the width of the brush 30.

  As shown in FIG. 3, four transport rolls 24 are provided along a shaft (rotating shaft) 27 at a predetermined interval. Four brushes 30 are provided at predetermined positions at positions corresponding to the transport rolls 24. The shape (tip shape) of the portion of the brush 30 that is in contact with the transport roll 24 is substantially flat following the surface of the transport roll 24. Further, the width W2 of the brush 30 is larger than the width W1 of the transport roll 24 (W2> W1). As a result, it is possible to reliably scrape off moisture adhering to the surface of the transport roll 24.

  FIG. 4 is a perspective view of the transport roll 24. In FIG. 4, the symbol D indicates the diameter of the transport roll 24, and the symbol P indicates the width of the groove 24a.

  As shown in FIG. 4, the plurality of grooves 24 a on the surface of the transport roll 24 are formed in parallel with the shaft 27 of the transport roll 24. For example, the plurality of grooves 24 a are formed so as to divide the outer periphery of the transport roll 24 into 12 parts. When the diameter D of the transport roll 24 is about 16 mm and the width W1 of the transport roll 24 is 20 to 25 mm, the width P of the groove 24a is preferably about 2 mm.

  As described above, since the plurality of grooves 24a are formed on the surface of the transport roll 24, the moisture generated from the sheet material after the toner is fixed enters into the grooves 24a. And the moisture which penetrate | invaded the inside of the groove | channel 24a is scraped off with the brush 30 pressed so that the front-end | tip might bite into the conveyance roll 24. FIG. The water scraped off by the brush 30 naturally evaporates while flowing along the brush 30.

  Therefore, in this embodiment, since the water adhering to the surface of the conveyance roll 24 is scraped off when the brush 30 is in sliding contact with the surface of the conveyance roll 24, the water adheres to the sheet material by removing the water generated by the dew condensation. Occurrence of problems due to this is prevented. Moreover, since it is not the structure which prevents dew condensation by heating like patent document 1, it can aim at low power consumption and can suppress the fall of durability. Therefore, it is possible to provide the image forming apparatus 1 that can reduce power consumption, suppress a decrease in durability, and prevent the occurrence of problems caused by moisture adhering to the sheet material.

  In the present embodiment, since the groove 24a parallel to the shaft 27 of the transport roll 24 is formed on the peripheral surface of the transport roll 24 in contact with the brush 30, moisture that has entered the groove 24a by the brush 30 is absorbed. It is scraped off. Therefore, it is possible to provide the image forming apparatus 1 that can significantly prevent the occurrence of problems due to moisture adhering to the sheet material.

  Moreover, in this embodiment, since the brush 30 is pressed so that it may bite into the groove | channel 24a of the conveyance roll 24, the water | moisture content which penetrate | invaded inside the groove | channel 24a is scraped off reliably. Therefore, it is possible to provide the image forming apparatus 1 that can reliably prevent the occurrence of problems due to moisture adhering to the sheet material.

  In the present embodiment, since the transport roll 24 is formed of silicon rubber, the transport roll 24 has flexibility, and the brush 30 is likely to bite into the groove 24 a of the transport roll 24. For this reason, since the brush 30 is pressed so as to surely bite into the groove 24a of the transport roll 24, the moisture that has entered the groove 24a is reliably scraped off. Therefore, it is possible to provide the image forming apparatus 1 that can reliably prevent the occurrence of problems due to moisture adhering to the sheet material.

  In the present embodiment, the shape of the tip of the brush 30 is substantially flat following the surface of the transport roll 24, but is not limited thereto. FIG. 5 is a front view showing a brush 30A having a different form from the brush 30 of the present embodiment. As shown in FIG. 5, the tip shape of the brush 30 </ b> A (the shape of the portion in contact with the transport roll 24) may be an uneven shape that undulates along the rotation axis direction of the transport roll 24. As a result, the tip of the brush 30 </ b> A is much easier to bite into the groove 24 a of the transport roll 24, so that moisture that has entered the groove 24 a is reliably scraped off. Therefore, it is possible to provide the image forming apparatus 1 that can reliably prevent the occurrence of problems due to moisture adhering to the sheet material.

  DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 20 ... Fixing device, 24 ... Conveyance roll, 24a ... Groove, 27 ... Shaft (rotary shaft), 30 ... Brush, L ... Conveyance path

Claims (4)

A fixing device for fixing toner on a sheet material;
A transport roll for transporting the toner-fixed sheet material;
Have a, a brush for scraping the water adhering to the surface of the transfer roll in sliding contact with the peripheral surface of the conveying rolls,
An image forming apparatus , wherein a groove parallel to a rotation axis of the transport roll is formed in a portion in contact with the brush on a peripheral surface of the transport roll . The image forming apparatus according to claim 1, wherein the brush is pressed so as to bite into a groove of the transport roll . The image forming apparatus according to claim 2, wherein the transport roll is formed of silicon rubber . The shape of the part which contact | connects the said conveyance roll of the said brush becomes uneven | corrugated shape which undulates along the rotating shaft direction of the said conveyance roll, The any one of Claims 1-3 characterized by the above-mentioned. Image forming apparatus.

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