JP2010230945A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of enhancing durability of an air blower. <P>SOLUTION: The image forming apparatus includes at least: a plurality of heat generation sources (fixing unit 20, solenoid 7, etc.); the air blower (air discharge fan F) configured to cool the heat generated by the plurality of heat generation sources; and a partitioning member (ventilation path 8) for dividing and partitioning a ventilation area set by the air blower into parts having different areas in accordance with the respective heat generation sources; wherein the durability of the air blower can be enhanced. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an image forming apparatus.

  Conventionally, laser printers, full-color printers, multifunction peripherals, and the like using colorants such as toner have been developed and spread as image forming apparatuses.

  These image forming apparatuses have a heat source such as a heater in a heat fixing device for fixing a toner image on a recording medium and a solenoid used for switching a ventilation path. A cooling fan is provided so that the electrical components do not break down and the toner does not melt.

  For example, in Japanese Patent No. 3372711, a first air path that sends cooling air generated by a fan to an electrical component inside the image forming apparatus main body, and a second that sends cooling air generated by the fan to an optical scanning unit. And an air path opening / closing member that opens and closes the second air path according to the air volume of the fan, and opens and closes the second air path by the air path opening / closing member, whereby the cooling air is supplied to the first air path. A structure is disclosed in which it is possible to change whether the air is sent to both the second air passage and only the first air passage.

Japanese Patent No. 3372711

  An object of the present invention is to provide an image forming apparatus capable of improving the durability of a blower.

  In order to solve the above-described problem, the image forming apparatus according to the first aspect of the present invention is set to a plurality of heat generation sources, a blower that cools heat generated by the plurality of heat generation sources, and the blower. The ventilation region is provided with at least partition members that divide and partition into different areas corresponding to the heat generation sources.

  According to a second aspect of the present invention, there is provided the image forming apparatus according to the first aspect, wherein the heat generation source is a fixing device that fixes an image formed of a colorant on a recording medium, and other than the fixing device. The area of the ventilation region that cools the heat source other than the fixing device is smaller than the ventilation region that cools the fixing device.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect of the present invention, the partition member is configured by a ventilation path that is open to a ventilation surface of the blower. A wall of the ventilation path facing the blower is inclined and arranged so as to narrow the interval toward the blower.

  According to a fourth aspect of the present invention, there is provided an image forming apparatus according to the third aspect, wherein a conveyance guide portion for the recording medium is formed on an outer surface of the ventilation path.

  According to the first aspect of the invention, there is an effect that the durability of the blower in the image forming apparatus can be improved.

  According to the invention described in claim 2, the cooling efficiency can be increased.

  According to the third aspect of the present invention, it is possible to reduce wind noise caused by the blower.

  According to the invention described in claim 4, it is possible to reduce the number of parts and to reduce the cost.

1 is a schematic diagram illustrating a configuration example of an image forming apparatus according to an embodiment. 1 is a perspective view conceptually showing a main part of an image forming apparatus according to an embodiment. FIG. 3 is a longitudinal sectional view showing a main part of the image forming apparatus shown in FIG. 2. FIG. 3 is a perspective view showing a ventilation path used in the image forming apparatus shown in FIG. 2. It is the horizontal sectional view of the housing | casing upper part which showed the state which attached the ventilation path shown in FIG. It is the elements on larger scale which showed the positional relationship of the ventilation path and air blower shown in FIG. 3 is a graph showing cooling performance related to a solenoid in the image forming apparatus shown in FIG. 2. FIG. 3 is a diagram showing a divided state of two cooling regions in the image forming apparatus shown in FIG. 2.

  Hereinafter, an embodiment as an example of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

  FIG. 1 is a schematic view showing an image forming apparatus according to an embodiment of the present invention.

  An image forming apparatus 10 shown in FIG. 1 is a so-called tandem type image forming apparatus in which four color process cartridges (image forming units, drum cartridges) 11a, 11b, 11c, and 11d are sequentially arranged in a vertical direction in a housing 10a. It is. Further, a conveyance path 12 through which a sheet (recording medium) P is conveyed from a substantially vertical lower side to an upper side is disposed at a corresponding position of each of the process cartridges 11a to 11d. Further, a paper feed cassette 13 for storing the paper P that is transported through the transport path 12 and sequentially transfers the toner image is disposed below (upstream) the process cartridge 11a at the lowermost stage (uppermost stream). Has been.

  In the present embodiment, a part of the paper feed cassette 13 protrudes to the back side (rear side, in side) of the housing 10a due to the size of the paper P stored in the paper feed cassette 13. If the paper P is a small size, it does not protrude from the housing 10a.

  The process cartridges 11 a to 11 d form toner images for yellow (Y), magenta (M), cyan (C), and black (K) in order from the upstream side of the conveyance path 12. Each of the process cartridges 11a to 11d is a cartridge in which a photosensitive drum (image holding member) 14 and various electrophotographic devices sequentially arranged around the photosensitive drum 14 are integrally formed. is there. The electrophotographic device includes a charging roller that precharges the photosensitive drum 14, and a developing device that develops the electrostatic latent image formed on the photosensitive drum 14 charged by the charging roller with each corresponding toner. (Heating element) 27, a cleaning device for removing waste toner on the photosensitive drum 14, and the like.

  An exposure device 15 common to the process cartridges 11a to 11d is disposed on the opposite side of the transport path 12 of the process cartridges 11a to 11d. The exposure device 15 drives and drives four semiconductor lasers (not shown) based on image data corresponding to each color. Then, the light from the four semiconductor lasers is deflected and scanned by a polygon mirror (not shown) and guided to an exposure point on the photosensitive drum 14 through an fθ lens (not shown) and a plurality of reflection mirrors. A charge loss region is formed on the charged photoconductive drum 14 to draw an electrostatic latent image.

  A conveyance belt 16 that circulates along the conveyance path 12 is disposed at a location corresponding to each photosensitive drum 14 of the process cartridges 11a to 11d. The transport belt 16 is made of a belt material capable of electrostatically adsorbing the paper P, and is stretched around a pair of driving roller 17A and driven roller 17B. Further, an adsorption roller 18 for electrostatically adsorbing the paper P to the conveyance belt 16 is disposed in the conveyance path 12.

  A transfer roller 19 is disposed on the back side of the conveyance belt 16 corresponding to each photosensitive drum 14 of the process cartridges 11a to 11d. The transfer roller 19 is for transferring the toner image formed on the photosensitive drum 14 onto the paper P by bringing the photosensitive drum 14 and the paper P on the transport belt 16 into close contact with each other.

  A fixing device (heating element) 20 is provided on the conveyance path 12 further above (downstream side) of the uppermost (most downstream) process cartridge 11d. The fixing device 20 includes a heating roller 20 a provided with a heat source and a pressure roller 20 b that is in pressure contact with the heating roller 20 a, and the paper P onto which the toner image has been transferred is the heating roller 20 a of the fixing device 20. The toner image is fixed to the paper P by heat and pressing force by passing through the pressure contact area between the toner and the pressure roller 20b.

  On the upper part of the housing 10a, a conveyance guide (not shown) for guiding the paper on which the toner image is fixed by the fixing device 20, and a paper discharge roll 29A for discharging the paper guided by the conveyance guide, 29B and a paper discharge unit 21 that is formed integrally with the housing 10a and accommodates the paper discharged by the paper discharge rolls 29A and 29B. In addition, a reversing conveyance path 22 is disposed in the casing 10 a for reversing the paper P, one side of which has been fixed by the fixing device 20, and sending it again to the conveyance path 12.

  Here, on the upper part of the conveyor belt 16, an ADC sensor 31 for adjusting the toner density composed of a reflection type photosensor that detects the patch mark density of the toner formed on the conveyor belt 16, and the conveyor belt 16 of the ADC sensor 31. A cleaner 32 that contacts the surface of the conveyor belt 16 on the downstream side thereof to clean the surface of the conveyor belt 16, a recovery unit (not shown) for recovering toner and the like removed from the surface of the conveyor belt 16 by the cleaner 32, Is arranged.

  An exhaust fan (an example of a blower) F is disposed in the housing 10 a of the image forming apparatus 10.

  The exhaust fan F discharges heat generated from a heat generation source such as a fixing device 20 and a solenoid, which will be described later, to the outside of the apparatus to cool each part inside the apparatus as described above.

  As shown in FIGS. 2 and 3, the image forming apparatus 10 according to the present exemplary embodiment includes a fixing unit 20 including a superheated roll 3 a and a pressure roll 3 b at the center of the housing 10 a, and an upper portion of the fixing unit 20. Is provided with a paper discharge section 4 located on the side opposite to the paper discharge section 4.

  The image forming apparatus 10 is configured as, for example, a double-sided copying machine, and includes a paper path switching flapper 6 in the paper discharge unit 4.

  The paper path switching flapper 6 guides the paper P, which has been formed by the image forming section and sent to the paper discharge section 4, to the path reversing section 4a that returns the paper P into the housing 10a, or on both sides. This selects whether to guide the image-formed sheet P to the sheet discharge port 4b, and is operated by a solenoid 7 installed at one end of the sheet discharge unit 4 (see FIG. 5).

  In the image forming apparatus 10, the paper P on which the image is formed by the image forming unit taken out from the paper supply unit is sent to the course reversing unit 4a through the fixing device 20, and the path reversing unit 4a again causes the housing 10a. Sent in. The sheet P is image-formed on the back side by the image forming unit, is sent upward through the fixing device 20, and is discharged to the sheet discharge port 4b.

  Incidentally, in the image forming apparatus 10, the heat generated by the fixing device 20 and the heat generated by the solenoid 7 of the paper switching flapper 6 are cooled by the exhaust fan F.

  The heat generated in the solenoid 7 is guided to the exhaust fan F through the ventilation path 8.

  As shown in FIG. 4, the ventilation path 8 is formed by a ceiling wall 8 a and a bottom wall 8 b that are arranged in parallel to each other and a back wall (guide wall) 8 c that connects one side of the longitudinal direction. A cross section perpendicular to the direction is formed in a U shape.

  And the back wall 8c is arrange | positioned so that a space | interval may be narrowed gradually toward the exhaust fan F as shown by the dotted line in FIG.

  The tip of the ventilation path 8 (the end opposite to the end on the solenoid side) occupies about 1/4 of the entire ventilation area of the exhaust fan F as shown in FIG.

  And the space | interval L between the front-end | tip of the ventilation path 8 and the exhaust fan F is set to about 5-50 mm.

  Note that if the value of the interval L is too small, wind noise is generated, and if it is too large, the effect of dividing the ventilation region is reduced.

  The bottom wall 8b of the ventilation path 8 is provided with a length larger than the width of the paper P, and a plurality of ribs 8d extending vertically from the bottom wall are formed on the bottom surface of the bottom wall 8b.

  The lower end of the rib 8d constitutes a conveyance guide for the paper P. Further, a concave portion 8e is formed in the exhaust fan F side intermediate portion of the ventilation path 8, and a blower housing portion is formed there.

  According to the image forming apparatus 10, when the exhaust fan F is driven, the heat generated in the fixing device 20 is sucked into the ventilation path 8 through the ribs 8 d and discharged from the exhaust fan F to the outside of the housing 10 a. Further, heat generated by the solenoid 7 is sucked into the ventilation path 8 from an opening formed at one end of the ventilation path 8, guided to the back wall 8c and guided to the exhaust fan F, and from the exhaust fan F to the casing. 10a is discharged outside.

  A slit 7a is formed in the casing of the solenoid 7 along the flow direction formed by the exhaust fan F.

  According to the image forming apparatus 10, the cooling performance related to the solenoid 7 is higher in cooling efficiency than the characteristic line C when the ventilation path 8 is not provided, as indicated by the characteristic line B in FIG. 7. Understood.

  In the above embodiment, the ratio of the area of the air blowing area for cooling the solenoid 7 in the exhaust fan F and the area of the air blowing area for cooling the fixing device 20 is 1: 3. This is set in order to cool each heat source in a well-balanced manner, and the area ratio of the air blowing area is appropriately set according to each heat source so as not to cause a pressure difference in each air blowing area. .

  However, when the area of the air blowing area of each heat source becomes the same, the shaft collapses and the noise becomes larger, so the areas of the air blowing areas are made different.

  Moreover, the shape of each ventilation area | region may not be rectangular shape, but may be divided | segmented by the line segment (arc or straight line) which connects two adjacent sides, as shown, for example in FIG.

  Moreover, although the example which cools with the exhaust fan F which discharges | emits the atmosphere in the housing | casing 10a outside in the said embodiment is shown, even if it is the case of the air blower which suck | inhales external air in the housing | casing 10a. Good.

  Further, as a heat generation source to be cooled, not only the solenoid 7 but also other heat generation sources may be targeted.

  Although the invention made by the present inventor has been specifically described based on the embodiment, the embodiment disclosed in this specification is an example in all respects and is limited to the disclosed technology. Should not be considered. That is, the technical scope of the present invention should not be construed restrictively based on the description in the above-described embodiment, but should be construed according to the description of the scope of claims. All modifications are included without departing from the technical scope equivalent to the described technique and the gist of the claims.

  The image forming apparatus according to the present invention can be applied to a copying machine, a laser printer, a full-color printer, a multifunction machine, a facsimile machine, and the like.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 10a Case 20 Fixing device 27 Developing device F Exhaust fan (blower)
4 Paper discharge unit 5 Blower 6 Paper path switching flapper 7 Solenoid 8 Ventilation path 8c Back wall (guide wall)

Claims (4)

Multiple heat sources,
A blower for cooling the heat generated by the plurality of heat generation sources;
A partition member that divides and partitions the ventilation area set in the blower into different areas, corresponding to the heat generation sources,
An image forming apparatus comprising: The heat generation source is
A fixing device for fixing an image formed of a colorant on a recording medium, and a heat source other than the fixing device,
The image forming apparatus according to claim 1, wherein an area of a ventilation region for cooling a heat source other than the fixing device is smaller than a ventilation region for cooling the fixing device. The partition member is
Consists of a ventilation path that opens to the ventilation surface of the blower,
3. The image forming apparatus according to claim 1, wherein a wall of the ventilation path facing the blower is inclined so as to be narrowed toward the blower. 4.   The image forming apparatus according to claim 3, wherein a conveyance guide portion for the recording medium is formed on an outer surface of the ventilation path.

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