JP2007010814A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which is simple and inexpensive without using extra power, properly removes moisture from only a photosensitive drum and eliminates heating of other parts. <P>SOLUTION: A heat pipe conducting heat to the photosensitive drum from a fixing roller is installed and the moisture is removed from the photosensitive drum by using the waste heat of the fixing roller. Thus, the moisture can be removed properly only from the photosensitive drum, without using the extra power. The heat pipe is formed to have one heat absorption pipe and a plurality of heat radiation pipes, so that the most efficient moisture removal is achieved according to the internal structure of the image forming apparatus. In addition, a sensor for detecting temperature and humidity near the photosensitive drum is provided to achieve optimum moisture removal reflecting the temperature and humidity of the photosensitive drum. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a facsimile machine, a printer, a copying machine, and a multifunction machine, and more particularly to an image forming apparatus that performs printing using a photosensitive drum and a fixing roller.

  2. Description of the Related Art In recent years, image forming apparatuses such as facsimiles, printers, copiers, and multifunction machines have become widespread not only in offices but also in general households. Among these, there are many image forming apparatuses that perform printing by the photosensitive drum 11 and the fixing roller 14 as shown in FIG.

  That is, the image forming apparatus 40 first attaches toner to the surface of the photosensitive drum 11 based on the image data stored in the memory or the like, and transfers the toner to the printing paper. Then, the toner transferred onto the printing paper is heated by the fixing roller 14, so that the image forming apparatus 40 melts the toner and fixes it on the printing paper.

  In order to perform such heating and melting, as shown in FIG. 5, the fixing roller 14 is usually provided with a halogen heater 15, so that when the power of the image forming apparatus 40 is turned on, fixing is performed. The temperature of the roller 14 is 160 ° C to 180 ° C.

  On the other hand, as the photosensitive drum 11, an amorphous silicon drum having excellent durability is most commonly used. However, this amorphous silicon drum has the following problem because it has a characteristic of being easily wet.

  That is, the photosensitive drum 11 charges its surface based on the above image data, thereby adhering the toner to be transferred to the printing paper to the surface. If the photosensitive drum 11 is humid, this charging is performed. As a result, the image data cannot be accurately reflected. In particular, when printing a color image, uneven color tends to occur.

  For this reason, it is necessary to appropriately dehumidify the photosensitive drum 11. Techniques for this purpose are disclosed in the following patent documents.

  Each of these is a technique for dehumidifying the photosensitive drum by providing a heater inside the image forming apparatus and sending warm air to the photosensitive drum.

That is, as shown in FIG. 4, for example, a heater 41 is provided below the photosensitive drum 11, and hot air generated by the heater 41 is blown to the photosensitive drum 11 by the fan 42. As a result, the photosensitive drum 11 can be dehumidified.
JP-A-10-2139947 JP 2003-177654 A

  However, the technique of the above-mentioned patent document has the following problems.

  First, since electric power for driving the heater 41 and the fan 42 is required, it is not preferable from the viewpoint of energy saving. In particular, since the heater 41 is an electric heater, it consumes a considerable amount of power.

  Next, since the air is blown by the fan 42, there is a risk that parts other than the photosensitive drum 11 are also heated. In particular, if a portion related to software control of the image forming apparatus 40, such as a memory, is heated, the entire image forming apparatus 40 may run out of heat. In order to prevent this, it is necessary to appropriately exhaust the hot air used for dehumidification of the photosensitive drum 11 to the outside of the image forming apparatus 40. However, if a device for that purpose is separately provided, the cost increases.

  The present invention has been made in view of such problems, and is simple and low-cost without using extra power, appropriately dehumidifying only the photosensitive drum, and heating other portions. An object of the present invention is to provide an image forming apparatus having no image.

  In order to achieve the above object, the present invention employs the following means.

  The present invention is an image provided with a photosensitive drum that adheres toner to be transferred to a printing paper based on image data to the surface, and a fixing roller that fixes the toner to the printing paper by heating the toner transferred to the printing paper It assumes a forming device.

  First, in such an image forming apparatus, a heat pipe that conducts heat from the fixing roller to the photosensitive drum is installed. That is, the waste heat of the fixing roller is used to dehumidify the photosensitive drum. Thereby, only the photosensitive drum can be appropriately dehumidified without using extra power.

  Next, this heat pipe is formed so as to include one heat absorption tube and a plurality of heat radiation tubes. This achieves the most efficient dehumidification in accordance with the internal structure of the image forming apparatus.

  Further, a sensor for detecting the temperature and humidity in the vicinity of the photosensitive drum and a control means for controlling the distance between the heat pipe of the heat pipe and the photosensitive drum based on the output of the sensor are provided. As a result, optimum dehumidification reflecting the temperature and humidity of the photosensitive drum is realized.

  According to the above, an image forming apparatus that does not consume extra power to use waste heat, is simple and low in cost, and appropriately dehumidifies only the photosensitive drum and does not heat other portions. Can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 4 is an internal configuration diagram of the image forming apparatus of the present invention. A latent image is formed around the photosensitive drum 11 by irradiating the charger 31 for uniformly charging the photosensitive drum and the photosensitive drum 11 charged based on image data stored in a memory (not shown) or the like. A laser 32 and a developing device 33 for attaching toner to the latent image are provided.

  The toner that forms an image to be transferred to the printing paper based on the image data adheres to the surface of the photosensitive drum 11 by the developing unit 33. This toner is transferred onto the printing paper 13 by the transfer roller 12. The fixing roller 14 heats the toner transferred to the printing paper 13 and presses it with a press roller 19 to fix the toner on the printing paper 13.

  Printing is generally performed in this manner, but the fixing roller 14 is provided with the halogen heater 15 for performing the above-described heating, and the surface temperature of the fixing roller 14 is maintained at 160 ° C. to 180 ° C. .

  The image forming apparatus of the present invention is characterized in that a heat pipe 16 that conducts heat from the fixing roller 14 to the photosensitive drum 11 is provided. That is, the photosensitive drum 11 is dehumidified using waste heat of the fixing roller 14. Thereby, only the photosensitive drum 11 can be appropriately dehumidified without using extra power.

  Here, various types of heat pipes 16 such as a hollow iron pipe and a metal pipe in which a volatile gas is sealed are commercially available. These are appropriately formed and used.

  FIG. 2 shows an example of the shape of the heat pipe 16 in the present invention. In this example, the heat pipe 16 includes one heat absorption tube 21 and a plurality of heat radiation tubes 22a, 22b, and 22c. Although this does not appear in FIG. 2, when other parts of the image forming apparatus must be installed between the photosensitive drum 11 and the fixing roller 14, heat is generated by avoiding the other parts. In order to conduct, the heat pipe 16 is thus formed. Therefore, the formation method is not limited to the example of FIG.

  In particular, when a heat pipe in which a volatile gas is sealed is used, unevenness in heat dissipation of the heat pipe occurs depending on how the volatile gas is convected. When the plurality of heat radiating tubes 22a, 22b, and 22c are provided as in the present invention, unevenness in heat radiation due to the convection can be reduced, and the surface of the photosensitive drum 11 can be uniformly dehumidified.

  By the way, when the photosensitive drum 11 is heated and dehumidified, if the temperature is too high, the toner melts on the surface of the photosensitive drum 11 and the toner adheres to the photosensitive drum 11. In order to prevent this, it is appropriate to heat the photosensitive drum 11 to 45 ° C. to 60 ° C.

  In order to realize such appropriate heating, the image forming apparatus of the present invention includes a sensor 17 that detects the temperature and humidity of the photosensitive drum 11. Then, based on the output of the sensor 17, control means 18 for controlling the distance between the heat radiating pipe of the heat pipe 16 and the photosensitive drum 11 is provided.

  Specifically, as shown in FIG. 3, the control means 18, which is a program stored in the memory 34 based on the output of the sensor 17, drives the motor M to connect the heat pipe 16 to the arrow A in FIG. Rotate in direction B.

  For example, when the temperature of the photosensitive drum 11 is too high, rotating the motor M in the direction of arrow A moves the heat radiating tubes 22a, 22b, and 22c of the heat pipe 16 away from the photosensitive drum 11, and heats the photosensitive drum 11. Do not overdo it. On the other hand, if the temperature of the photosensitive drum 11 is too low, rotating the motor M in the direction of arrow B brings the heat radiating tubes 22a, 22b, 22c of the heat pipe 16 closer to the photosensitive drum 11, and Heat.

  The sensor 17 is designed to detect not only the temperature of the photosensitive drum 11 but also the humidity. For example, in winter, the photosensitive drum 11 may be sufficiently dehumidified even if the temperature of the photosensitive drum 11 is low. Conversely, in summer, the photosensitive drum 11 may be sufficiently dehumidified even if the temperature is high. Because. By providing the control means 18 in this way, optimum dehumidification reflecting the temperature and humidity of the photosensitive drum 11 can be realized.

  This is because if the heat radiating tubes 22a, 22b, 22c of the heat pipe 16 are positioned above the heat absorbing tube 21, the waste heat of the fixing roller 16 can be used without waste. This is because heat generally tends to conduct upward. For the same reason, it can be said that the heat radiation pipes 22a, 22b, and 22c are positioned below the photosensitive drum 11 to eliminate wasteful use of waste heat. Since the entire surface does not leak and approaches the heat radiating tubes 22a, 22b, and 22c, this positional relationship may not be strict.

  The image forming apparatus according to the present invention is simple and low-cost without using extra power, can appropriately dehumidify only the photosensitive drum, and does not heat other portions. Therefore, it is useful as a facsimile machine, a printer, a copying machine, a multifunction machine or the like.

FIG. 3 is a diagram illustrating a printing mechanism of the image forming apparatus of the present invention. FIG. 3 is a diagram illustrating a printing mechanism of the image forming apparatus of the present invention. The block diagram which shows control of a heat pipe. FIG. 6 is a structural diagram of a conventional image forming apparatus. FIG.

Explanation of symbols

11 photosensitive drum
12 Transfer roller
13 printing paper
14 Fixing roller
15 halogen heater
16 heat pipe
17 sensors
18 Control means
19 press roller
21 Endothermic tube
22a, 22cb, 22c Radiation tube
30 memory
M motor
40 image forming device
41 heater
42 fans

Claims (3)

Image formation comprising a photosensitive drum for adhering to the surface toner to be transferred to a printing paper based on image data, and a fixing roller for fixing the toner to the printing paper by heating the toner transferred to the printing paper In the device
An image forming apparatus comprising a heat pipe that conducts heat from the fixing roller to the photosensitive drum. The image forming apparatus according to claim 1, wherein the heat pipe includes one endothermic tube and a plurality of heat radiating tubes. 3. The sensor according to claim 1, further comprising: a sensor that detects a temperature and humidity of the photosensitive drum; and a control unit that controls a distance between the heat-radiating pipe of the heat pipe and the photosensitive drum based on an output of the sensor. Image forming apparatus.

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