JP2006011147A - Image forming apparatus - Google Patents

Abstract

The present invention provides a copying machine capable of reliably preventing temperature rise due to the amount of heat of a document reading device and a printing section and contamination inside the apparatus due to contaminants when an abnormality occurs in the copying machine.
When an abnormality occurs in the copying machine, the operations of the document reading device and the printing unit 3 are urgently stopped, while the first to the first temperature until the surface temperature of the heating roller of the fixing device reaches a predetermined temperature (for example, 60 ° C.). Control is performed by the control unit so as to continue the rotation of the third fans 71 to 73.
[Selection] Figure 1

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 quantity and contaminants of an operating device to the outside of the apparatus body when an abnormality occurs in the apparatus body.

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

  By the way, in such an image forming apparatus, when an abnormality occurs due to a paper jam or the like when an image is formed by the image forming unit or when the original is read by the original reading unit, all operation devices (original reading) except for the control unit and the power supply board are generated. And the image forming unit) are shut down together with the fan.

  Therefore, the amount of heat generated by the heat source (the light source of the document reading unit and the fixing device of the image forming unit) of the operating device or the amount of heat generated by the power supply board before being shut down due to the occurrence of an abnormality is exhausted to the outside of the device body by the fan The temperature inside the apparatus rises. In addition, if the operating devices are shut down at the same time together with the fans when an abnormality occurs, the scattered developer and ozone and other contaminants that float inside the device main body will stay outside the device main body without being discharged and contaminate the device main body. It will end up.

  The present invention has been made in view of such a point, and an object of the present invention is to ensure 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 when an abnormality occurs in the apparatus main body. An object of the present invention is to provide an image forming apparatus capable of preventing the above.

  In order to achieve the above object, according to the present invention, an operation device that operates an apparatus main body by intake or exhaust by rotation of a fan during operation of the apparatus main body (for example, a light source that generates heat when an original is read by an original reading section, an image forming section) The amount of heat from the fixing device that is heated when fixing the developer in the apparatus, the power supply board that generates heat when supplying power to the operating device in the apparatus main body, and contaminants that contaminate the inside of the apparatus main body are outside the apparatus main body. On the premise of the image forming apparatus to be discharged, control means for controlling the operation of the operation device and the rotation of the fan is provided. Then, when an abnormality occurs in the apparatus main body, the control means performs an emergency stop of the operation of the operation apparatus while controlling the fan to continue rotating until the temperature in the apparatus main body reaches a predetermined temperature. Yes.

  Due to this specific matter, when an abnormality due to a paper jam or the like occurs when an image is formed by the image forming unit or when the original is read by the original reading unit, all the operating devices (the original reading unit and the image forming unit except for the control unit and the power supply board). ) All at once, the fan continues to rotate, so the heat source of the operating device (light source of the document reading unit, fixing device and power supply board of the image forming unit) is shut down by the occurrence of an abnormality. Even if the amount of heat generated or the amount of heat generated by the power supply board is abnormal (after the operating device is shut down), the fan will smoothly discharge it outside the device body, and it is possible to reliably prevent the temperature inside the device body from rising. It becomes possible. In addition, contaminants such as scattered developer and ozone floating in the main body of the device are smoothly discharged by the fan that continues to rotate even after the occurrence of an abnormality. It becomes possible to do.

  Further, when the rotation or stoppage of the fan is controlled by the control means based on the heat amount from the fixing device, the rotation of the fan is based on the heat amount of the fixing device that has the largest heat amount and is difficult to decrease in temperature within the main body of the device. Therefore, the amount of heat from the operating device is smoothly discharged from the device main body by the fan, and the temperature rise in the device main body can be more reliably prevented.

  In short, by controlling the fan to continue to rotate until the temperature inside the device main body reaches a predetermined temperature when an abnormality occurs, the amount of heat from the operating device and contaminants floating in the device main body can be controlled by the fan. It is possible to discharge smoothly to the outside of the main body, to reliably prevent the temperature inside the apparatus main body from rising, and to reliably prevent contamination inside the apparatus main body due to contaminants.

  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, the 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. As shown in FIG. 2, the scanner unit 2 and the automatic document feeder 4 constitute a document reading device as a document reading unit. 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 as a light source, 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 36a having a semicircular cross section is disposed at the upstream end of the main conveyance path 36 (the 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.

<Description of Automatic Document Feeder 4>
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.

  The operations of the printing unit 3 (image forming system 31 and paper transport system 32) and the document reading device (scanner unit 2 and automatic document feeding unit 4) are controlled by a control unit (not shown). It has become so. Further, in the vicinity of the printing unit 3, a power supply board 69 that supplies power to the printing unit 3 and the document reading apparatus in accordance with a command from the control unit is provided.

-Explanation of fan-
Next, as a characteristic feature of the present embodiment, the amount of heat generated during operation of the printing unit 3 for operating the copying machine 1 and the document reading device (scanner unit 2 and automatic document feeding unit 4) and the inside of the copying machine 1 are described. A fan that discharges pollutants out of the copier 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 fixing the developer in the printing unit, a power supply board 69 that generates heat when power is supplied to the printing unit 3 and the document reading device, and the like. The second fan 72 is introduced by the first fan 71 and is supplied to the heating roller 39a and the power source. It is used for discharging air required for cooling the substrate 69 and the like, as well as scattered developer and ozone and other contaminants floating and contaminating in the housing to the outside of the copying machine 1 by the action of negative pressure. In this case, the first and second fans 71 and 72 are also controlled by the control unit.

  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 third fan 73 is also controlled by the control unit.

  Here, when the image is formed by the image forming system 31 of the printing unit 3 or when the original 6 is read by the original reading device, the image forming paper conveyed by the paper conveying system 32 or the original conveyed by the automatic document feeder 4 is used. The flow of control by the control unit when an abnormality due to jam or the like occurs in FIG. 6 will be described with reference to FIG.

  First, when an abnormality due to a jam or the like occurs, in step ST1 of FIG. 3, all the document reading devices except the power supply board 69 and the printing unit 3 are urgently stopped simultaneously, while the first to third fans 71 to 73 are rotated. To continue. Next, in step ST2, the fact that “jamming has occurred” is displayed on the display section of the operation panel (not shown), and the removal of the jammed image forming paper or original, that is, the removal of jammed paper is urged. Then, in step ST3, the apparatus waits until the jammed paper (image forming paper or original in which a jam has occurred) is removed, and then in step ST4, the copying machine 1 is initialized. In this initialization process, the control of the first to third fans 71 to 73 is returned to the state before the abnormality occurred.

  At this time, the fan control for continuing the rotation of the first to third fans 71 to 73 is performed according to the procedure of steps ST11 to ST13 in parallel with the procedure of steps ST2 to ST4.

  That is, after the rotation of the first to third fans 71 to 73 is continued in step ST1, the amount of heat from the heating roller 39a of the fixing device 39, that is, the detected value (heating roller 39a) detected by the thermistor in step ST11. It is determined whether or not the surface temperature is equal to or higher than a predetermined temperature (for example, 60 ° C.). If the determination in step ST11 is YES when the surface temperature of the heating roller 39a is equal to or higher than the predetermined temperature, it is determined in step ST12 whether or not the copying machine 1 has been initialized. If the determination in step ST12 is YES when the copying machine 1 is initialized, the process proceeds to step ST5. If the copying machine 1 is not initialized, the above step is performed. Return to ST11. On the other hand, if the determination in step ST11 is NO in which the surface temperature of the heating roller 39a is less than the predetermined temperature, the rotation of the first to third fans 71 to 73 is stopped in step ST13.

  Then, in step ST5, it is determined whether or not to continue image formation on the image forming paper or the document on which the jam has occurred. If the determination in step ST5 is YES in which image formation on the image forming paper or document is continuously performed, the process waits until the start key is pressed in step ST6. Thereafter, after restarting the image forming process in step ST7, the process waits until the image forming process is completed in step ST8, and then shifts to the standby state of the copying machine 1. On the other hand, if the determination in step ST5 is NO in which image formation of the image forming paper or document is not continued, the process waits until the clear key for canceling the image forming process is pressed in step ST9, and then copying. The machine 1 enters the standby state.

  Therefore, in the above-described embodiment, the image forming paper transported in the paper transport system 32 when the image is formed by the image forming system 31 of the print unit 3 or the original 6 is read by the original reading device, or transported by the automatic document feeder 4. If an abnormality due to a jam or the like occurs in the document 6 being used, the rotation of the first to third fans 71 to 73 continues even if all the document reading devices except the power supply board 69 and the printing unit 3 are stopped at once. Therefore, the amount of heat generated by the exposure light source 21 of the scanner unit 2 and the heating roller 39a of the fixing device 39 of the print unit and the amount of heat generated by the power supply substrate 69 before the shutdown due to the occurrence of an abnormality or after the occurrence of an abnormality ( Also after the shutdown of the printing unit 3 and the document reading device), negative pressure action and convection by the first to third fans 71 to 73 Would be smoothly discharged to the outside copying machine 1, it is possible to reliably prevent the temperature rise in the copying machine 1. In addition, the first to third fans 71 to 73 that continue to rotate even after the occurrence of an abnormality smoothly discharges contaminants such as scattered developer and ozone floating in the casing of the copying machine 1 to the outside of the copying machine 1, Contamination in the copying machine 1 due to contaminants can be reliably prevented.

  Further, the rotation of the first to third fans 71 to 73 after the occurrence of abnormality is controlled so as to continue until the surface temperature of the heating roller 39a reaches a predetermined temperature (for example, 60 ° C.). The rotation of each of the fans 71 to 73 is continued based on the heat amount of the heating roller 39a of the fixing device 39 that has the largest heat amount and is difficult to lower the temperature in the copying machine 1, and from the document reading device and the printing unit 3 This amount of heat is smoothly discharged outside the copying machine 1 by the fans 71 to 73, which is very advantageous in preventing the temperature increase in the copying machine 1 more reliably.

  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 negative pressure action and convection action by 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?

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 flowchart figure which shows the flow of control by the control part when abnormality by jam etc. generate | occur | produces.

Explanation of symbols

1 Copying machine (image forming device)
2 Scanner unit (operation device)
21 Exposure light source
3 Print section (image forming section, operating device)
39 Fixing Device 69 Power Supply Board 71 First Fan (Fan)
72 Second Fan (Fan)
73 Third Fan (Fan)

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 rotation of the fan;
This control means, when an abnormality occurs in the apparatus main body, performs an emergency stop of the operation of the operation apparatus, while controlling the fan to continue rotating until the temperature in the apparatus main body reaches a predetermined temperature. An image forming apparatus. In the image forming apparatus according to claim 1,
The fan supplies heat to the operating device in the main body of the apparatus, heat from the light source that generates heat when reading the original in the original reading unit, heat from the fixing device that is heated when fixing the developer in the image forming unit An image forming apparatus having a function of discharging heat from the power supply board that generates heat and polluting substances floating in the apparatus body. In the image forming apparatus according to claim 1 or 2,
The image forming apparatus, wherein the control unit controls rotation or stop of the fan based on an amount of heat from the fixing device.

Images