JP2006011148A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copier capable of effectively preventing the increase in in-machine temperature due to the heat capacity of a scanner part and a printing part and in-machine contamination due to contaminating substance, even when an optionally installed paper feed unit is operated. <P>SOLUTION: When the paper feed unit 51 is made in an active state in reply to the demand to form an image on an image forming paper of B4, the power consumption required to operate the scanner part 2, an image forming system 31, a paper transporting system 32 and the paper feed unit is fetched out of a memory 9, and power supply to respective fans 71 to 73 is controlled by a controller 8 so as to be set about 70%. Further, when the temperature of a power source substrate 69 is equal to or exceeding a prescribed temperature and also the paper feed unit is in an active state, the power supply is controlled as follows: the power supply to a 1st and 2nd fans for cooling the heat roller 39a and the power source substrate is set to be about 60% among 70% of the power supply to be supplied to respective fans, and the power supply to a 3rd fan for cooling the exposure light source 21 of the scanner part is set to be about remaining 40%. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus such as an electrophotographic copying machine or a laser beam printer, and more particularly, to measures for smoothly discharging the heat amount and contaminants of an operating device to the outside of the apparatus body within the range of safety standards.

Conventionally, in this type of image forming apparatus, an operation device that operates the apparatus main body by intake or exhaust by rotation of a fan during operation of the apparatus main body, particularly an original reading device that includes a light source that generates heat when reading an original document. The amount of heat generated by an operating device such as an image forming unit having a fixing device heated when fixing a developer, a developer, a power supply substrate that generates heat when power is supplied to the operating device in the device main body, Contaminants such as flying developer and ozone that float and contaminate inside the main body are discharged out of the main body of the apparatus to suppress an increase in the temperature inside the apparatus and remove the contaminants (for example, patents). Reference 1). In this case, operation devices such as the document reading unit, the image forming unit, and the power supply substrate are controlled by the control unit.
JP-A-9-212066

  Incidentally, in recent years, in such an image forming apparatus, in addition to the basic apparatus of the apparatus main body, a post-processing apparatus that performs post-processing such as staple processing and punch hole processing, a job separator apparatus, a multi-stage paper discharge tray apparatus, a large capacity There is a tendency to attach an optional operation device such as a paper feed cassette device. In that case, even if an optional operation device is attached to the apparatus main body, the entire image forming apparatus must be used within the safety standards of the power supply. Therefore, it is necessary to effectively use power consumption within a limited range.

  On the other hand, the rotation of the fan is forced to stop due to the lack of absolute power of the entire image forming apparatus accompanying the attachment of the optional operating device, and the heat source of the operating device (the light source of the original reading unit, the fixing device of the image forming unit, and the power supply board) The amount of heat generated cannot be discharged out of the apparatus main body by the fan, and the temperature inside the apparatus rises. Moreover, due to the suspension of the fan rotation, contaminants such as scattered developer floating in the device main body and ozone generated from the charger are not discharged outside the device main body, but stay in the device main body and contaminate the inside of the device main body. Become.

  The present invention has been made in view of such a point, and the object of the present invention is to efficiently rotate a fan with power consumption within a limited range even if an optional operation device is attached. Another object of the present invention is to provide an image forming apparatus capable of effectively preventing temperature rise in the apparatus main body due to the amount of heat of the operating apparatus and contamination in the apparatus main body due to contaminants.

  To achieve the above object, according to the present invention, an operation device that operates the apparatus main body by intake or exhaust by rotation of a fan during operation of the apparatus main body (for example, when fixing a light source or developer that generates heat when reading a document). An image forming apparatus which discharges heat from a fixing device to be heated, a power supply board that generates heat when power is supplied to an operation device in the apparatus main body, and contaminants contaminating the apparatus main body to the outside of the apparatus main body. As a premise, there is provided a control means for controlling the operation of the operating device and the power supply amount for rotating the fan. The amount of power supplied to the fan is controlled by the control means in accordance with the operating status of an optional operating device connected to the apparatus main body.

  Because of this specific matter, the amount of power supplied to the fan is controlled within the range of safety standards according to the operating status of the optional operating device attached to the main body of the device. Therefore, when the optional operating device is operated, It is not necessary to stop the fan, and the fan efficiently rotates with the remaining power required for the operation of the optional operation device. As a result, the amount of heat generated by the heat source (light source, fixing device and power supply board) of the operating device is smoothly exhausted to the outside of the device main body by the fan, and the temperature rise inside the device main body is effectively prevented. Is possible. In addition, contaminants such as scattered developer and ozone floating in the apparatus main body are smoothly discharged out of the apparatus main body by the fan, and it is possible to effectively prevent contamination in the apparatus main body due to the contaminant.

  In particular, the following configurations are listed as specifying timing for controlling the power supply amount to the fan.

  In other words, when an image formation request is made to the apparatus main body, the power supply amount to the fan is controlled according to the operation status of the optional operation apparatus.

  By this specific matter, the power supply amount to the fan is controlled according to the operation status of the optional operation device at the time of image formation request with the highest power consumption, and the fan can be efficiently rotated within the range of the safety standard It becomes.

  Furthermore, when the temperature of the power supply board that generates heat when supplying power to the operating device is equal to or higher than a predetermined temperature, the power supply amount to the fan is controlled according to the operating status of the optional operating device. In this case, the IC and electronic components on the power supply board can be efficiently cooled by the fan, and problems such as malfunction of the power supply board can be reliably prevented.

  In short, by controlling the amount of power supplied to the fan within the safety standards within the operating conditions of the optional operating device, the fan can be efficiently rotated without stopping the fan when the optional operating device is operating. It is possible to effectively discharge the amount of heat from the operating device and the contaminants floating inside the device body to the outside of the device body, and reliably prevent the temperature inside the device body from rising. Contamination can be reliably prevented.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. In this embodiment, a case where the image forming apparatus according to the present invention is applied to a digital copying machine will be described.

-Description of overall configuration of copier-
FIG. 1 schematically shows an internal configuration of a copying machine 1 as an image forming apparatus according to the present embodiment. As shown in FIG. 1, a copying machine 1 includes a scanner unit 2 as an operation device, a print unit 3 (operation device) as an image forming unit, and an automatic document feeder 4 (optional operation device) provided as an option. ). As shown in FIG. 2, the scanner unit 2 and the automatic document feeder 4 constitute a document reading device. Hereinafter, each part will be described.

<Description of Scanner Unit 2>
The scanner unit 2 reads image of a document placed on a document table 41 made of transparent glass or the like, or a document image fed one by one by the document automatic sheet feeding unit 4 to generate image data. It is. The scanner unit 2 includes an exposure light source 21, a plurality of reflecting mirrors 22, 23, 24, an imaging lens 25, and a photoelectric conversion device (CCD: Charge Coupled Device) 26.

  The exposure light source 21 emits light to a document placed on the document table 41 of the automatic document feeder 4 or a document conveyed through the automatic document feeder 4. Each reflecting mirror 22, 23, 24 reflects the reflected light from the document once in the left direction in the drawing as shown by a broken line in FIG. Reflected in the right direction in the figure so as to face.

  As a document image reading operation, when a document is placed on the document table 41 (when used as a “sheet fixing method”), the exposure light source 21 and the reflecting mirror 22 are positioned at the positions indicated by solid lines in FIG. An image of the entire document is read by scanning in the horizontal direction along the document table 41 between the positions indicated by the virtual lines. On the other hand, when reading a document conveyed by the automatic document feeder 4 (when used as a “sheet moving method”), the exposure light source 21 and the reflecting mirror 22 are fixed at positions indicated by solid lines in FIG. When the document passes through the document reading unit 42 of the automatic document feeder 4 to be read, the image is read. The document reading unit 42 includes a platen glass 42a, a document pressing plate 42b, an exposure light source 21, reflecting mirrors 22, 23, 24, an imaging lens 25, and a photoelectric conversion element 26, which will be described later.

  The light reflected by the reflecting mirrors 22, 23, 24 and passing through the imaging lens 25 is guided to the photoelectric conversion element 26, and the reflected light is converted into an electric signal (original image data) by the photoelectric conversion element 26. It is like that.

<Description of Print Unit 3>
The printing unit 3 includes an image forming system 31 and a paper transport system 32.

  The image forming system 31 includes a laser scanning unit (not shown) and a drum-type photoconductor 31b. The laser scanning unit irradiates the surface of the photoreceptor 31b with laser light based on the document image data converted by the photoelectric conversion element 26. The photoreceptor 31b rotates in a direction indicated by an arrow in FIG. 1, and an electrostatic latent image is formed on the surface of the photoreceptor 31b when irradiated with laser light from a laser scanning unit.

  In addition to the laser scanning unit, a developing device 31c, a transfer charger 31d, a cleaning device (not shown), a static eliminator, and a main charger are sequentially arranged around the outer periphery of the photoreceptor 31b in the circumferential direction. . The developing device 31c develops the electrostatic latent image formed on the surface of the photoreceptor 31b into a visible image with toner. The transfer charger 31d transfers the toner image formed on the surface of the photoreceptor 31b onto an image forming sheet (not shown) as a recording medium. The cleaning device removes the toner remaining on the surface of the photoreceptor 31b after the toner transfer. The static eliminator removes residual charges on the surface of the photoreceptor 31b. The main charger is configured to charge the surface of the photoreceptor 31b before the electrostatic latent image is formed to a predetermined potential.

  Therefore, when an image is formed on the image forming paper, the surface of the photoreceptor 31b is charged to a predetermined potential by the main charger, and the laser scanning unit emits laser light based on the document image data to the surface of the photoreceptor 31b. Irradiate. Thereafter, the developing device 31c develops a visible image with toner on the surface of the photoreceptor 31b, and the toner image is transferred onto the image forming paper by the transfer charger 31d. Further, after that, the toner remaining on the surface of the photoreceptor 31b is removed by the cleaning device, and the residual charge on the surface of the photoreceptor 31b is removed by the static eliminator. Thereby, one cycle of the image forming operation (printing operation) on the image forming paper is completed. By repeating this cycle, it is possible to continuously form images on a plurality of image forming sheets.

  On the other hand, the paper transport system 32 transports image forming paper stored in a paper cassette 33 as a paper storage unit one by one to perform image formation by the image forming system 31, and also forms image formed paper. Is discharged to a paper discharge tray 35 as a paper discharge unit.

  The paper transport system 32 includes a main transport path 36 and a reverse transport path 37. One end of the main conveyance path 36 is branched and faces the discharge side of the paper cassette 33, and the other end faces the discharge tray 35. One end of the reverse conveyance path 37 is connected to the main conveyance path 36 on the upstream side (lower side in the drawing) of the transfer charger 31d, and the other end is downstream of the transfer charger 31d. (Upper side in the figure) is connected to the main transport path 36.

  A pickup roller 36 a is disposed at the upstream end of the main conveyance path 36 (a portion facing the discharge side of the paper cassette 33). By the rotation of the pickup roller 36a, the image forming sheets stored in the sheet cassette 33 can be intermittently fed to the main transport path 36 one by one.

  Registration rollers 36d and 36d are disposed on the upstream side of the main transport path 36 relative to the position where the transfer charger 31d is disposed. The registration rollers 36d and 36d convey the image forming sheet while aligning the toner image on the surface of the photoreceptor 31b and the image forming sheet. A fixing device 39 for fixing the toner image transferred onto the image forming sheet is disposed downstream of the position at which the transfer charger 31d is disposed in the main conveyance path 36. The fixing device 39 includes a heating roller 39a having a heater 39h therein, and a pressure roller 39b pressed against the heating roller 39a via an image forming sheet. Then, the surface temperature of the heating roller 39a is detected by a thermistor (not shown), and the energization amount to the heater 39h is controlled by a control unit to be described later so that the detected value is held at the fixing set temperature. ing. A pair of paper discharge rollers 36 g and 36 g for discharging the image forming paper to the paper discharge tray 35 are disposed at the downstream end of the main transport path 36.

  Conveying rollers 37a and 37a are disposed in the reverse conveying path 37, and when the image forming paper is supplied to the reverse conveying path 37, the image forming paper is conveyed by the conveying rollers 37a and 37a, and the registration rollers. The image forming sheet is reversed upstream of 36d and conveyed again through the main conveying path 36 toward the transfer charger 31d. That is, image formation can be performed on the back surface of the image forming paper.

  As shown in FIG. 1, a sheet feeding unit 51 as an optional operation device is disposed below the copying machine 1 so as to overlap the lower surface of the sheet cassette 33. As described above, when the paper feeding unit 51 is superimposed on the paper cassette 33, the downstream end of the paper feeding path 51 a of the paper feeding unit 51 is in communication with the upstream side of the registration roller 36 d of the main transport path 36. . In the paper feed path 51a of the paper feed unit 51, a pickup roller 51c that intermittently feeds image forming sheets stored in the paper feed cassette mechanism 51b one by one to the paper feed path 51a, and the pickup roller A transport roller 51d is provided for feeding the image forming paper fed to the paper feed path 51a by 51c to the main transport path 36. A paper feed path 51 a of the paper feed unit 51 is provided across the paper feed unit 51 and the lower end portion in the copying machine 1. In this case, in the paper feed cassette mechanism 51b of the paper feed unit 51, image forming paper having a different size from the image forming paper stored in the paper cassette 33, for example, A4 size image forming paper is stored in the paper cassette 33. If it is stored, B4 size image forming paper is stored.

<Description of automatic document feeder>
Next, the automatic document feeder 4 will be described with reference to FIG. The automatic document feeder 4 is configured as a so-called automatic duplex document feeder. The automatic document feeder 4 can be used as a sheet moving type, and includes a document tray 43, an intermediate tray 44, a document discharge tray 45, and a document transport system 46 that transports documents between the trays 43, 44, 45. It has.

  The document transport system 46 includes a main transport path 47 for transporting the documents 6, 6,... Placed on the document tray 43 to the intermediate tray 44 or the document discharge tray 45 via the document reading unit 42. A sub-transport path 48 for supplying the document 6 on the tray 44 to the main transport path 47 is provided.

  A document pick-up roller 47a and a separating roller 47b are disposed at the upstream end of the main conveyance path 47 (a portion facing the discharge side of the document tray 43). A separation plate 47c is disposed below the separation roller 47b, and one of the documents 6, 6,... On the document tray 43 is separated from the separation roller 47b as the document pickup roller 47a rotates. The sheet is fed to the main transport path 47 through the space between the plates 47c. A document entry sensor 47d for detecting the passage of the document 6 is disposed at a junction (A portion in the figure) between the main transport path 47 and the sub transport path 48. Further, PS rollers 47e and 47e are disposed on the downstream side of the position where the document input sensor 47d is disposed. The PS rollers 47e and 47e adjust the leading edge of the document 6 and the image reading timing of the scanner unit 2 and supply the document 6 to the document reading unit 42. That is, the PS rollers 47e and 47e temporarily stop the conveyance of the original 6 while the original 6 is supplied, and adjust the timing to supply the original 6 to the original reading unit 42.

  The document reading unit 42 includes a platen glass 42a and a document pressing plate 42b. When the document 6 supplied from the PS rollers 47e and 47e passes between the platen glass 42a and the document pressing plate 42b, the exposure light source is provided. The light from 21 passes through the platen glass 42a and is irradiated onto the document 6. At this time, the document image data is acquired by the scanner unit 2. A biasing force by a coil spring 42c is applied to the back surface (upper surface) of the document pressing plate 42b. Thereby, the document pressing plate 42b is in contact with the platen glass 42a with a predetermined pressing force, and prevents the document 6 from being lifted from the platen glass 42a when passing through the document reading unit 42.

  On the downstream side of the document reading section 42, a transport roller 47f and a document discharge roller 47g are provided. The document 6 that has passed through the document reading unit 42 is discharged to the intermediate tray 44 or the document discharge tray 45 through the transport roller 47f and the document discharge roller 47g. Of the rollers 47e, 47f, and 47g, the roller indicated by the arrow in the rotation direction in FIG. 2 is a driving roller, and the roller that contacts the driving roller is a driven roller.

  An intermediate tray swinging plate 44 a is disposed between the document discharge roller 47 g and the intermediate tray 44. The intermediate tray swinging plate 44a can swing between a position 1 indicated by a solid line and a position 2 indicated by a virtual line in FIG. . When the intermediate tray swinging plate 44 a is at position 1, the document 6 discharged from the document discharge rollers 47 g and 47 g is collected to the document discharge tray 45. On the other hand, when the intermediate tray swinging plate 44 a is at position 2, the document 6 discharged from the document discharge rollers 47 g and 47 g is discharged to the intermediate tray 44. At the time of paper discharge to the intermediate tray 44, as shown by a virtual line in FIG. 2, the edge of the document 6 (right edge in the drawing) is sandwiched between the document discharge rollers 47g and 47g. In this state, the document discharge roller 47g rotates in the reverse direction, whereby the document 6 is supplied to the sub-transport path 48, and is again sent to the main transport path 47 through the sub-transport path 48. The reverse rotation operation of the document discharge roller 47g is performed by adjusting the sending of the document 6 to the main conveyance path 47 and the image reading timing. As a result, the image on the back side of the document 6 is read by the document reading unit 42.

  A document detection sensor 4A for detecting whether or not the document 6 exists on the document tray 43 is provided at the upstream end of the main transport path 47 (a position near the right end in FIG. 2 in the document tray 43). ing. Further, in the vicinity of the downstream end of the main transport path 47 and in the vicinity of the branching portion (B portion in the figure) with the sub transport path 48, the leading end (in the transport direction) of the document 6 transported on the main transport path 47. A document leading edge detection sensor 4B is provided which can detect that the downstream edge) has passed.

  As shown in FIG. 3, the printing unit 3 (image forming system 31 and paper transport system 32), document reading device (scanner unit 2 and automatic document feeding unit 4), and paper feeding unit 51 (pickup roller 51c and The operation of the transport rollers 51d) is controlled by a controller 8 as a control means. Further, in the vicinity of the printing unit 3, a power supply board 69 made of an IC or an electronic device that supplies power to the printing unit 3, the document reading device, and the paper feeding unit 51 in accordance with a command from the controller 8 is provided. A heat radiating plate (not shown) for radiating heat generated from the power supply board 69 is provided with a temperature sensor 69a as temperature detecting means, and the temperature of the power supply board 69 is detected by the temperature sensor 69a. Yes. Further, the memory 9 connected to the controller 8 includes a scanner unit 2, an automatic document feeder 4, an image forming system 31 and a paper transport system 32 of the print unit 3, and a paper feed unit 51 (a pickup roller 51c and a transport roller 51d). The power consumption required during the operation is stored separately.

-Explanation of fan-
Next, as a characteristic feature of the present embodiment, the amount of heat generated during operation of the printing unit 3 that operates the copying machine 1 and the scanner unit 2 of the document reading apparatus and contaminants that contaminate the inside of the copying machine 1 are copied. The fan discharged outside will be described.

As shown in FIG. 1, the print unit is partitioned by a housing with respect to the scanner unit 2, and a first fan 71 is provided at an upper position on the right side surface of the print unit and faces the paper discharge tray 35. A second fan 72 is provided at a lower position on the left side surface below the downstream end of the conveyance path 36.
The first fan 71 includes a heating roller 39a of the fixing device 39 that is heated when the developer is fixed in the printing unit 3, and a power supply substrate 69 that generates heat when power is supplied to the printing unit 3 and the document reading device. The second fan 72 is introduced by the first fan 71 so as to introduce air outside the copying machine 1 into the copying machine 1 in order to cool the heating roller 39a and the like. It is used for discharging air required for cooling the power supply board 69 and the like, as well as scattered developer and ozone and other contaminants floating and contaminating inside the casing, to the outside of the copying machine 1 by the action of negative pressure. . In this case, the power supply amount for rotating the first and second fans 71 and 72 is controlled by the controller 8.

  As shown in FIG. 2, the scanner unit 2 is partitioned by a casing above the print unit 3, a third fan 73 is provided on the right side surface, and a slit is formed on the left side surface. 74 is provided. The third fan 73 is used for introducing air outside the copying machine 1 into the copying machine 1 (inside the casing) in order to cool the exposure light source 21 that generates heat when the scanner unit 2 reads the document. On the other hand, the slit 74 is provided to discharge the air introduced by the third fan 73 and required for cooling the exposure light source 21 to the outside of the copying machine 1 by the action of convection. In this case, the power supply amount for rotating the third fan 73 is controlled by the controller 8.

  As a feature of the present invention, the controller 8 sets the power supply amount to each of the fans 71 to 73 within the safety standard range according to the operation status of the paper feed unit 51 (the pickup roller 51c and the transport roller 51d). Control is performed so as to cover a total power consumption of 1500 W (voltage value 100 V, current value 15 A). That is, the amount of power supplied to each of the fans 71 to 73 can be covered within a total power consumption of 1500 W even if the power supply unit 51 is set to 100% when not in use. In contrast, when the paper feeding unit 51 is in use, the power consumption required when the scanner unit 2, the automatic document feeder 4, the image forming system 31, the paper transport system 32, and the paper feeding unit 51 are operated is taken out of the memory 9. Control is performed so that the amount of power supplied to each of the fans 71 to 73 is set to about 80% so as to cover the power consumption within a range of 1500 W.

  The controller 8 controls the amount of power supplied to each of the fans 71 to 73 according to the operation status of the paper feed unit 51 when an image formation request is made by the operation unit 70. That is, when the operation unit 70 makes an image formation request for B4 size image forming paper and the paper feeding unit 51 is in an operating state, the scanner unit 2, the automatic document feeder 4, the image forming system 31, and the paper conveying system. 32 and the paper feeding unit 51 are controlled so that the power consumption required for the operation of the paper feeding unit 51 is taken out from the memory 9 and set to about 70% so that the power supply amount to each of the fans 71 to 73 can be covered within the total power consumption 1500 W. ing.

  Further, when the temperature of the power supply board 69 detected by the temperature sensor 69a is equal to or higher than a predetermined temperature (for example, 50 ° C. or higher), the controller 8 sends the fans 71 to 73 according to the operation status of the paper feed unit 51. The power supply amount is controlled. In this case, when the temperature of the power supply board 69 is equal to or higher than a predetermined temperature (for example, 50 ° C. or higher) and the paper feed unit 51 is in an operating state, the scanner unit 2 and the automatic document feeder 4 taken out from the memory 9 are used. The sum of the power consumption required for the operation of the image forming system 31, the paper transport system 32, and the paper feeding unit 51 and the power supply amount to each of the fans 71 to 73 (70% of the maximum power supply amount) is 1500 W. The power supply amount to the first and second fans 71 and 72 and the power supply amount to the third fan 73 are controlled so as to cover within the range. Specifically, of the power supply amount in which only 70% of the maximum power supply amount is supplied to each of the fans 71 to 73 when the temperature of the power supply board 69 is equal to or higher than a predetermined temperature and the paper feeding unit 51 is in an operating state. The power supply amount to the first and second fans 71 and 72 for cooling the heating roller 39a and the power supply board 69 is set to about 60%, and the third fan 73 for cooling the exposure light source 21 of the scanner unit 2 is set. It is controlled so that the remaining power supply amount is set to about 40%.

  Therefore, in the above embodiment, the power supply amount to each of the fans 71 to 73 can be covered within the safety standard range (within the total power consumption 1500 W) according to the operation status of the paper feed unit 51 attached as an option. Is controlling. At this time, when the image forming request for the B4 size image forming paper is made by the operation unit 70 and the paper feeding unit 51 is in the operating state, the scanner unit 2, the automatic document feeding unit 4, the image taken out from the memory 9. To each of the fans 71 to 73, the power consumption required when the forming system 31, the paper transport system 32, and the paper feeding unit 51 are in operation and the power supply amount to each of the fans 71 to 73 do not exceed the range of the total power consumption 1500W. The power supply amount is controlled to be set to about 70% of the maximum power supply amount.

  Therefore, it is not necessary to stop each of the fans 71 to 73 when the paper feeding unit 51 is operated, and each of the remaining power (about 70% of the maximum power supply amount) required for the operation of the paper feeding unit 51 is used. The fans 71 to 73 rotate efficiently. As a result, the amount of heat generated by the exposure light source 21 of the scanner unit 2, the fixing device 39 of the image forming system 31, and the power supply substrate 69 is smoothly discharged out of the copying machine 1 by the fans 71 to 73. The temperature rise in the machine 1 can be effectively prevented. In addition, contaminants such as scattered developer and ozone floating in the copying machine 1 are also smoothly discharged out of the copying machine 1 by the first and second fans 71 and 72, and the contamination inside the copying machine 1 due to the contaminants is effective. Can be prevented.

  Further, when the temperature of the power supply board 69 is equal to or higher than a predetermined temperature and the paper feed unit 51 is in an operating state, the heating roller is included in the power supply amount that is supplied to each of the fans 71 to 73 only 70% of the maximum power supply amount. The power supply amount to the first and second fans 71 and 72 that cool the 39a and the power supply board 69 is set to about 60%, and the power supply amount to the third fan 73 that cools the exposure light source 21 of the scanner unit 2 Therefore, the first and second fans 71 and 72 are rotated at the power supply amount of about 60% of the power supply amount of 70% of the maximum power supply amount. Thus, the IC and electronic components of the power supply board 69 can be efficiently cooled, and malfunctions such as malfunction of the power supply board 69 can be reliably prevented. Moreover, the exposure light source 21 of the scanner unit 2 can be efficiently cooled by rotating the third fan 73 with a power supply amount that is about 40% of the power supply amount that is 70% of the maximum power supply amount.

  In addition, this invention is not limited to the said embodiment, The other various modifications are included. For example, in the above embodiment, the amount of heat and contaminants of the exposure light source 21 of the scanner unit 2, the heating roller 39a of the fixing device 39, and the power supply substrate 69 are copied by the negative pressure action and convection action of the first to third fans 71 to 73. The number of fans is not limited to this, but the number of fans is selected according to the amount of heat from the document reading device and the printing unit 3 and the location where the contaminant is generated. What should I do?

  In the above-described embodiment, the case where the paper feeding unit 51 is attached to the copying machine 1 as an optional operation device has been described. However, a post-processing device that performs post-processing such as stapling processing and punch hole processing, a job separator device, Optional operation devices such as a tray discharge tray device and a larger capacity paper cassette device may be appropriately combined and attached to the copier. In this case, consumption of the attached operation device during operation is acceptable. The amount of power supplied to each fan is changed according to the power.

1 is a diagram showing an outline of an internal configuration of a copying machine according to an embodiment of the present invention. FIG. 3 is a schematic diagram showing an automatic document feeder and its peripheral part. It is a block block diagram which shows the structure of control by a controller.

Explanation of symbols

1 Copying machine (image forming device)
2 Scanner unit (operation device)
3 Print section (operation device)
51 Paper feed unit (optional operation device)
69 Power supply board 71 First fan (fan)
72 Second Fan (Fan)
73 Third Fan (Fan)
8 Controller (control means)

Claims (3)

An image forming apparatus configured to discharge the heat amount of an operating device that operates the device main body by intake or exhaust by rotation of a fan during operation of the device main body and contaminants that contaminate the inside of the device main body to the outside of the device main body.
Control means for controlling the operation of the operating device and the amount of power supplied to rotate the fan;
The control means controls the amount of power supplied to the fan within the range of safety standards in accordance with the operating status of an optional operating device connected to the apparatus main body. In the image forming apparatus according to claim 1,
The control means controls the amount of power supplied to the fan according to the operation status of the optional operation device when an image formation request is made to the apparatus main body. In the image forming apparatus according to claim 1 or 2,
Temperature detecting means for detecting the temperature of the power supply substrate that generates heat when supplying power to the operating device;
The control means controls the amount of power supplied to the fan according to the operation status of the optional operation device when the temperature of the power supply board detected by the temperature detection means is equal to or higher than a predetermined temperature. An image forming apparatus.

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