JP2015069059A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of preventing a user from feeling uncomfortable about the operation sound of cooling means, or preventing power from being uselessly consumed.SOLUTION: In an image forming apparatus, a control part is configured to execute: temperature information acquisition processing S221 of acquiring temperature information which is equivalent to a temperature inside a housing according as an image formation part ends an image forming operation; and processing S222 of determining whether the temperature information acquired by the temperature information acquisition processing S221 is equivalent to a high temperature range or a low temperature range which is lower than the high temperature range. In a stop state after the image formation part ends the image forming operation, the control part executes; processing S225, S226 of allowing cooling means to operate when the temperature information is equivalent to the high temperature range; and processing S223 of not allowing the cooling means to operate when the temperature information is equivalent to the low temperature range.

Description

  The present invention relates to an image forming apparatus.

  Patent Document 1 discloses an example of a conventional image forming apparatus. The image forming apparatus includes a housing, an image forming unit, a cooling unit, and a control unit. The image forming unit is accommodated in the housing. The image forming unit performs an image forming operation for forming an image on a sheet. The image forming unit includes a heat generating unit such as a fixing device that generates heat by an image forming operation. The cooling means is a cooling fan or the like provided in the housing. The cooling means cools the inside of the housing that is heated by the heat generated by the heat generating portion. The control unit controls the image forming unit and the cooling unit.

JP 2003-76253 A

  In such a conventional image forming apparatus, for example, the control unit operates the cooling unit in a constant state while the image forming unit is performing the image forming operation. Further, even in a stopped state after the image forming unit finishes the image forming operation, it is common to perform one pattern control in which the control unit operates the cooling unit for a certain period while maintaining the same state. In this case, assuming that the inside of the housing is hot, the operation time of the cooling means is often set to be long.

  Here, the temperature inside the housing varies depending on, for example, the number of sheets when the image forming operation is continuously performed on a plurality of sheets, the duration of the image forming operation, and the like. Specifically, the temperature inside the housing differs between after the image forming operation is continuously performed on several tens of sheets and after the image forming operation is performed on one sheet. In general, the latter has a lower temperature rise.

  However, regardless of the actual temperature inside the housing, if the control unit always controls the cooling unit for one pattern, the cooling unit is unnecessary in the stop state after the image forming operation is finished. May work. This causes a problem that the user feels uncomfortable with the operating sound of the cooling means or that power is wasted.

  The present invention has been made in view of the above-described conventional situation, and provides an image forming apparatus that can prevent a user from feeling uncomfortable operation sound of a cooling unit or consuming power wastefully. With the goal.

An image forming apparatus of the present invention includes a housing,
An image forming unit that is housed in the housing, performs an image forming operation for forming an image on a sheet, and has a heat generating unit that generates heat by the image forming operation;
A cooling means for cooling the inside of the housing, which is provided in the housing and raises the temperature by heat generation of the heat generating portion;
A control unit for controlling the image forming unit and the cooling unit,
The control unit acquires temperature information corresponding to a temperature inside the housing with the end of the image forming operation in the image forming unit;
After determining whether the temperature information acquired by the temperature information acquisition process corresponds to a high temperature range or a low temperature range lower than the high temperature range, and after the image forming unit finishes the image forming operation In a stopped state, a first control that controls the cooling means to operate when the temperature information corresponds to the high temperature range, and does not operate the cooling means when the temperature information corresponds to the low temperature range. And a process.

  In the image forming apparatus of the present invention, the control unit executes the temperature information acquisition process and the first control process. When the control unit determines that the temperature information acquired along with the end of the image forming operation in the image forming unit corresponds to the low temperature range, it can be assumed that the temperature inside the housing is low. Is controlled not to operate. For this reason, in this image forming apparatus, it is possible to prevent the cooling means from operating unnecessarily in the stop state after the image forming operation is finished.

  Therefore, in the image forming apparatus of the present invention, it is possible to prevent the user from feeling uncomfortable with the operation sound of the cooling means or consuming power wastefully.

  It is desirable that the control unit be controllable to operate the cooling means at a plurality of levels including a high level with a high cooling capacity and a low level with a cooling capacity lower than the high level. In the first control process, when it is determined that the temperature information corresponds to the high temperature range, switching is performed between operating the cooling unit at a high level or operating the cooling unit at a low level according to the level of the temperature information. It is desirable to control as follows.

  According to this configuration, the control unit can finely control the cooling capacity exhibited by the cooling unit based on the temperature information acquired with the end of the image forming operation in the image forming unit. As a result, in this image forming apparatus, the temperature in the housing can be accurately cooled by the cooling means, and it is possible to further suppress that the user feels uncomfortable operation sound of the cooling means or wasteful power consumption.

An image forming apparatus of the present invention includes a housing,
An image forming unit that is housed in the housing, performs an image forming operation for forming an image on a sheet, and has a heat generating unit that generates heat by the image forming operation;
A cooling means for cooling the inside of the housing, which is provided in the housing and raises the temperature by heat generation of the heat generating portion;
A control unit for controlling the image forming unit and the cooling unit,
The control unit acquires temperature information corresponding to a temperature inside the housing with the end of the image forming operation in the image forming unit;
After determining whether the temperature information acquired by the temperature information acquisition process corresponds to a high temperature range or a low temperature range lower than the high temperature range, and after the image forming unit finishes the image forming operation In a stop state, when the temperature information corresponds to the high temperature range, a period for operating the cooling means is set to the first period, and when the temperature information corresponds to the low temperature range, the cooling means is operated. And a second control process for controlling the cooling means to stop after the elapse of the first period or the second period is set to a second period shorter than the first period. It is configured.

  In the image forming apparatus of the present invention, the control unit executes the temperature information acquisition process and the second control process. When the control unit determines that the temperature information acquired along with the end of the image forming operation in the image forming unit corresponds to the low temperature range, it can be assumed that the temperature inside the housing is low. The period for operating the is set to a second period shorter than the first period, and the cooling means is controlled to stop after the second period elapses. For this reason, in this image forming apparatus, it is possible to prevent the cooling means from operating unnecessarily in the stop state after the image forming operation is finished.

  Therefore, in the image forming apparatus of the present invention, it is possible to prevent the user from feeling uncomfortable with the operation sound of the cooling means or consuming power wastefully.

  In the second control process, it is further determined whether or not the temperature information acquired by the temperature information acquisition process corresponds to a range lower than the low temperature range, and in the stop state after the image forming unit finishes the image forming operation, the temperature information When the information corresponds to a range lower than the low temperature range, it is desirable to control the cooling means not to operate.

  According to this configuration, the control unit can finely control the period during which the cooling unit is operated based on the temperature information acquired with the end of the image forming operation in the image forming unit. As a result, in this image forming apparatus, it is possible to further suppress that the user feels the operation sound of the cooling means unpleasant or that power is wasted.

  It is desirable that the controller executes the temperature information acquisition process even while the image forming unit is performing the image forming operation. Then, the control unit determines whether the temperature information acquired by the temperature information acquisition process while the image forming unit is performing the image forming operation corresponds to the high temperature range or the low temperature range, and In a state where the forming unit is performing image forming operation, when the temperature information corresponds to the high temperature range, the cooling means is operated at a high level with a high cooling capacity, and when the temperature information corresponds to the low temperature range, the high level. It is desirable that the third control process for controlling the cooling means to operate at a low level having a lower cooling capacity is further executed.

  According to this configuration, the control unit can finely control the cooling capacity exhibited by the cooling unit based on the temperature information acquired while the image forming unit is performing the image forming operation. As a result, in this image forming apparatus, it is possible to further suppress that the user feels the operation sound of the cooling means unpleasant or that power is wasted.

  In the third control process, it is further determined whether or not the temperature information acquired by the temperature information acquisition process corresponds to a range lower than the low temperature range while the image forming unit is performing the image forming operation. When the temperature information corresponds to a range lower than the low temperature range while the image forming operation is being performed, it is desirable to control so that the cooling means is not operated.

  According to this configuration, the control unit can further finely control the cooling capacity exhibited by the cooling unit based on the temperature information acquired while the image forming unit is performing the image forming operation. As a result, in this image forming apparatus, it is possible to further suppress that the user feels the operation sound of the cooling means unpleasant or that power is wasted.

  The temperature information is preferably a variable that increases or decreases based on a change in at least one condition relating to an image forming operation that may cause a difference in the temperature inside the housing. According to this configuration, since the temperature inside the housing can be estimated indirectly by the variable, it is not necessary to provide a temperature sensor inside the housing. As a result, in this image forming apparatus, it is possible to suppress the user from feeling uncomfortable with the operating sound of the cooling means and wasteful power consumption while realizing a reduction in manufacturing cost.

  The temperature information includes the interval between the previous image forming operation and the subsequent image forming operation, the size of the sheet on which the image forming operation is performed, the number of sheets when the image forming operation is continuously performed on a plurality of sheets, and image formation. When the operation is continuously performed on a plurality of sheets, the supply interval of each sheet, the operating time of the drive source that drives the image forming unit, whether the image forming operation is in the high speed mode or the low speed mode, or the sleep mode in which the image forming unit pauses It is desirable that the variable be increased or decreased based on at least one of an elapsed time since the transition to, and an elapsed time from when the apparatus power source is turned off to when it is turned on. In this case, the control unit can accurately determine whether the temperature information corresponds to the high temperature range or the low temperature range, and can suitably control the cooling unit.

1 is a schematic cross-sectional view of an image forming apparatus of Example 1. FIG. 1 is a block diagram of an image forming apparatus according to Embodiment 1. FIG. 6 is a flowchart of addition / subtraction processing of a count value of a counter according to the image forming apparatus of Embodiment 1. 6 is a flowchart of addition / subtraction processing of a count value of a counter according to the image forming apparatus of Embodiment 1. 6 is a flowchart of power OFF button reception processing according to the image forming apparatus of Embodiment 1. 6 is a flowchart of a cooling fan control process in the image forming apparatus according to the first exemplary embodiment. 6 is a flowchart of a cooling fan control routine according to the image forming apparatus of Embodiment 1 during an image forming operation. 6 is a flowchart of a cooling fan control routine according to the end of the image forming operation in the image forming apparatus according to the first exemplary embodiment. 6 is a flowchart of a cooling fan control routine in the Ready mode according to the image forming apparatus of Embodiment 1. 10 is a flowchart of a cooling fan control routine that is associated with the end of the image forming operation in the image forming apparatus according to the second exemplary embodiment.

  Embodiments 1 and 2 embodying the present invention will be described below with reference to the drawings.

Example 1
As shown in FIG. 1, an image forming apparatus 1 according to the embodiment is an example of a specific aspect of the image forming apparatus of the present invention. The image forming apparatus 1 is a monochrome laser printer that forms a single color image on a sheet SH such as paper or an OHP sheet by an electrophotographic method. In FIG. 1, the right side of the paper is defined as the front side of the apparatus, and the left side of the paper is defined as the rear side. Hereinafter, each component provided in the image forming apparatus 1 will be described with reference to FIGS. 1 and 2.

<Outline configuration>
As shown in FIGS. 1 and 2, the image forming apparatus 1 includes a housing 2, a sheet cassette 9, and an image forming unit 10.

  As shown in FIG. 1, a discharge tray 2 </ b> B is formed on the upper surface of the housing 2 that is a substantially box-like body so as to be recessed downward. The sheet cassette 9 is disposed at the bottom of the interior 2 </ b> A of the housing 2. The sheet cassette 9 stores a plurality of sheets SH in a stacked state.

  A conveyance path P <b> 1 is provided in the inside 2 </ b> A of the housing 2. The conveyance path P1 advances from the rear end side of the sheet cassette 9 toward the rear surface side of the housing 2, and then changes its direction to the upper side and advances substantially vertically, and then changes its direction to the front side to the discharge tray 2B. It is a route to reach.

  As shown in FIGS. 1 and 2, the image forming unit 10 is accommodated in the interior 2 </ b> A of the housing 2. The image forming unit 10 includes a transport unit 20, a developing unit 30, an exposure unit 39, and a fixing device 37.

  As shown in FIG. 1, the conveyance unit 20 includes a supply roller 22, a separation roller 23, a separation pad 23A, conveyance roller pairs 24A and 24B, and discharge roller pairs 29A and 29B along the conveyance path P1. . As shown in FIG. 2, the transport unit 20 has a motor 20M. The supply roller 22, the separation roller 23, the transport roller pair 24A and 24B, and the discharge roller pair 29A and 29B are rotated synchronously by the motor 20M. The motor 20M is an example of the “drive source” in the present invention.

  As shown in FIG. 1, the supply roller 22 is located above the rear end of the sheet cassette 9. The separation roller 23 and the separation pad 23 </ b> A are located on the rear surface side of the housing 2 from the supply roller 22. The pair of transport rollers 24A and 24B is located at a portion whose direction is changed upward in the transport path P1. The pair of discharge rollers 29A and 29B is located at the portion of the transport path P1 whose direction is changed to the front side, that is, the most downstream side of the transport path P1, and faces the discharge tray 2B. And the conveyance path | route P1 is prescribed | regulated by the guide surface arrange | positioned between the said various rollers and rollers.

  The developing unit 30 is located in a substantially vertical part of the transport path P1. The exposure unit 39 is located on the front side of the housing 2 from the developing unit 30. The fixing device 37 is located above the developing unit 30 in a substantially vertical portion of the transport path P1.

  The supply roller 22 sends out the sheet SH stored in the sheet cassette 9 to the transport path P1. The separation roller 23 and the separation pad 23A separate the fed sheets SH one by one. The pair of conveying rollers 24 </ b> A and 24 </ b> B conveys the separated sheet SH toward the developing unit 30 and the fixing device 37. The discharge roller pairs 29A and 29B discharge the sheet SH that has passed through the fixing device 37 to the discharge tray 2B.

  The developing unit 30 includes a process cartridge 31 and a transfer roller 50. The process cartridge 31 is located on the front side of the substantially vertical portion of the transport path P1. The transfer roller 50 faces the process cartridge 31 from the rear side across a substantially vertical portion of the transport path P1.

  The process cartridge 31 includes a photosensitive drum 40, a developing roller 31A that contacts the photosensitive drum 40, a toner container 31B that supplies toner to the developing roller 31A, a charger 31C that positively charges the photosensitive drum 40, and the like. doing. The photosensitive drum 40 and the transfer roller 50 are also driven by the motor 20 </ b> M and rotate in synchronization with the rollers constituting the transport unit 20.

  The scanner unit 39 includes a laser light source, a polygon mirror, an fθ lens, a reflecting mirror, and the like, and irradiates the photosensitive drum 40 with a laser beam from above.

  The fixing device 37 includes a heat roller 37A and a pressure roller B that are opposed to each other with the conveyance path P1 interposed therebetween. The heat roller 37A incorporates a heater such as a halogen lamp, and generates heat when the heater is energized.

  The developing unit 30, the scanner unit 39, and the fixing device 37 form an image on the sheet SH conveyed along the conveyance path P1 as follows. That is, the surface of the photosensitive drum 40 is uniformly positively charged by the charger 31C as it rotates, and then exposed by the laser beam emitted by the scanner unit 39. As a result, the scanner unit 39 forms an electrostatic latent image corresponding to the image to be formed on the surface of the photosensitive drum 40. Next, the developing roller 31A supplies toner from the toner storage portion 31B to the electrostatic latent image on the surface of the photosensitive drum 40 to form a toner image. The toner image rotates while the photosensitive drum 40 is in contact with the conveyed sheet SH, and is transferred to the sheet SH by the negative voltage applied to the transfer roller 50. The fixing device 37 heats and presses the sheet SH that has passed through the developing unit 30 by the heat roller 37A and the pressure roller 37B, and fixes the toner image transferred to the sheet SH. Thus, the sheet SH on which the image is formed is discharged to the discharge tray 2B by the discharge roller pair 29A and 29B.

  In the image forming unit 10 operating in this way, the heat roller 37A of the fixing device 37 generates heat. In addition, each roller, the photosensitive drum 4, and the transfer roller 50 constituting the conveying unit 20 also generate heat due to friction with the sheet SH or the like. The motor 20M of the transport unit 20 also generates heat by being driven to rotate. The heat roller 37A included in the image forming unit 10, the rollers constituting the conveying unit 20, the photosensitive drum 4, the transfer roller 50, and the motor 20M are examples of the “heat generating unit” of the present invention. The temperature of the interior 2A of the housing 2 rises as these heat generating parts generate heat during the image forming operation. Among these heat generating portions, the heat roller 37A generates heat remarkably, and the temperature inside the housing 2A is easily raised.

  As shown in FIGS. 1 and 2, the image forming apparatus 1 includes a cooling fan 70. The cooling fan 70 is an example of the “cooling unit” in the present invention. The cooling fan 70 is provided on the side surface of the housing 2. The cooling fan 70 operates to discharge the heated air inside the housing 2 </ b> A to the outside of the housing 2. As a result, the interior 2A of the housing 2 becomes negative pressure, and the indoor air flows into the interior 2A of the housing 2 from an inlet (not shown). Thus, the cooling fan 70 cools the inside 2A of the housing 2 that is heated by the heat roller 37A as a heat generating part.

  As shown in FIG. 2, the image forming apparatus 1 includes an operation unit 60, a display unit 65, a network interface 69, a power switch 91, a power OFF button 95, and a control unit 80.

  The operation unit 60 includes a plurality of buttons. The operation unit 60 receives various input operations by the user, such as an instruction to execute an image forming process on the sheet SH. The display unit 65 includes a liquid crystal display, a lamp, and the like. The display unit 65 displays various setting screens, operation states, and the like. The network interface 69 is connected to an information terminal device 100 such as a PC or FAX via a communication line NT. The network interface 69 enables data communication with the information terminal device 100. The power switch 91 is a switch for turning on the image forming apparatus 1. The power OFF button 95 is a button for turning off the power of the image forming apparatus 1.

  The control unit 80 includes a CPU 81, a ROM 83, a nonvolatile NVRAM 85, a counter 87, and the like. Various programs for controlling the image forming apparatus 1 are recorded in the ROM 83. The NVRAM 85 stores various data for setting conditions and operating conditions, the count value of the counter 87, and the like.

  The control unit 80 is connected to the power switch 91, the image forming unit 10, the cooling fan 70, the operation unit 60, the network interface 69, the display unit 65, and the power OFF button 95. When the power switch 91 is operated to turn on the power of the image forming apparatus 1, the control unit 80 starts control of the image forming unit 10, the cooling fan 70, the operation unit 60, the display unit 65, and the like by the CPU 81. .

  When the control unit 80 receives an instruction to execute an image forming process on the sheet SH from the operation unit 60 or the information terminal device 100, the control unit 80 controls the conveying unit 20, the developing unit 30, the exposure unit 39, and the fixing device 37 that constitute the image forming unit 10. An image forming operation is performed by appropriately operating, and an image based on the received image data is formed on the sheet SH.

  In this embodiment, the control unit 80 performs the image forming operation in a high speed mode, that is, a mode in which the motor 20M operates at a normal motor speed, or a low speed mode, that is, the motor 20M operates at a motor speed half of the normal speed. The mode can be switched to.

  In the present embodiment, the control unit 80 shifts the image forming unit 10 from the Ready mode to the Sleep mode when the period during which the execution instruction of the image forming process for the sheet SH is not performed exceeds one minute in the Ready mode. Here, the Ready mode is a state in which the image forming unit 10 can immediately execute an image forming operation. The sleep mode is a state in which the image forming unit 10 is in a standby state and a warm-up operation is necessary to execute the image forming operation.

  When the power supply OFF button 95 is operated and the power supply of the image forming apparatus 1 is shut off, the control unit 80 ends the control of the image forming unit 10, the cooling fan 70, the operation unit 60, the display unit 65, and the like.

<Control of cooling fan by control unit>
The control unit 80 appropriately controls the cooling fan 70 while the image forming apparatus 1 is powered on, and causes the cooling fan 70 to cool the inside 2 </ b> A of the housing 2. Specifically, the controller 80 switches the cooling fan 70 between full speed and half speed, which is half the full speed, or stops the cooling fan 70. The full speed operation of the cooling fan 70 is an example of the “high level with high cooling capacity” of the present invention. The half-speed operation of the cooling fan 70 is an example of the “low level whose cooling capacity is lower than the high level” of the present invention.

  In the present embodiment, the control unit 80 controls the cooling fan 70 based on the count value of the counter 87 without using the temperature of the inside 2A of the housing 2 that is actually measured by the temperature sensor. The count value of the counter 87 is an example of “temperature information corresponding to the temperature inside the housing” in the present invention.

  Here, the count value of the counter 87 is a variable that increases or decreases based on changes in a plurality of conditions relating to an image forming operation that may cause a difference in the temperature of the interior 2A of the housing 2. Specific examples of conditions relating to the image forming operation that may cause a difference in the temperature of the interior 2A of the housing 2 are given below.

(1) Interval between job of previous image forming operation and job of subsequent image forming operation: Generally, the shorter the job interval, the easier the temperature inside 2A of housing 2 rises.
(2) Size of sheet SH on which image forming operation is performed: Generally, the smaller the size, the easier the temperature inside 2A of housing 2 rises.
(3) Number of sheets SH when the image forming operation is continuously performed on a plurality of sheets SH: Generally, as the number of sheets increases, the temperature inside the housing 2A becomes easier to increase.
(4) Supply interval of each sheet SH when the image forming operation is continuously performed on a plurality of sheets SH: Generally, the longer the supply interval, the easier the temperature inside the housing 2A rises.
(5) Operating time of the motor 20M that drives the conveying unit 20 of the image forming unit 10: Generally, the longer the operating time, the easier the temperature inside the housing 2A rises.
(6) Whether the image forming operation is in the high speed mode or the low speed mode: Generally, in the high speed mode, the temperature inside the housing 2A is more likely to rise.
(7) Elapsed time after shifting to the sleep mode in which the image forming unit 10 is paused: Generally, the longer the elapsed time after shifting to the sleep mode, the cooler the interior 2A of the housing 2 is due to heat dissipation or the like. It becomes easy.
(8) Elapsed time from when the apparatus power supply is turned off to when it is turned on: Generally, the longer the elapsed time from when the apparatus power supply is turned off until it is turned on, the cooler the interior 2A of the housing 2 is by heat dissipation or the like It becomes easy.

  When the apparatus power supply is turned on, the control unit 80 executes addition / subtraction processing of the count value of the counter 87 shown in FIGS. In addition, when the apparatus power is turned on, the control unit 80 executes a receiving process for the power OFF button 95 shown in FIG. Moreover, the control part 80 will perform the control process of the cooling fan 70 shown in FIGS. 6-9, if an apparatus power supply is turned ON.

<Count value addition / subtraction processing>
When the control unit 80 starts addition / subtraction processing of the count value of the counter 87 shown in FIGS. 3 and 4, first, in step S <b> 101 shown in FIG. 3, the count value of the counter 87 at the time of power OFF stored in the NVRAM 85 is used. Check. The count value is usually in the range of 0 to 150, and may exceed 150 depending on the operating status.

  Next, the control unit 80 proceeds to step S102 and subtracts the count value according to the elapsed time from when the apparatus power supply is turned off to when it is turned on. At this time, the control unit 80 refers to the previous power-off time stored in the NVRAM 85 and compares it with the current time to calculate the elapsed time. As the elapsed time from when the apparatus power supply is turned off to when it is turned on is longer, the inside 2A of the housing 2 is estimated to be cooled, and the count value is greatly subtracted. Step S102 corresponds to the condition (8) described above.

  Next, the control unit 80 proceeds to step S103 and causes the image forming unit 10 to perform a warm-up operation. The warm-up operation is an operation of starting energization of the heat roller 37A, causing each roller constituting the transport unit 20 to idle, and stirring the toner stored in the toner storage unit 31B.

  Next, the control unit 80 proceeds to step S104 and sets the image forming unit 10 to the Ready mode. In this embodiment, the Ready mode duration is set to 1 minute, but this duration can be set to a desired time as appropriate.

  Next, the control unit 80 proceeds to step S105 and determines whether an image forming job has been received within one minute. If “No” in step S105, the process proceeds to step S113 shown in FIG. On the other hand, if “Yes” in step S105, the process proceeds to step S106.

  When the process proceeds from step S105 to step S106, the control unit 80 determines whether or not the count value is less than 150. If “No” in step S106, the process proceeds to step S110. On the other hand, if “Yes” in step S106, the process proceeds to step S107.

  When the process proceeds from step S106 to step S107, the control unit 80 selects the high-speed mode, operates the motor 20M at a normal motor speed, and causes the image forming unit 10 to execute an image forming operation. That is, since the count value is less than 150, the control unit 80 estimates that the internal temperature 2A of the housing 2 is not excessively increased, and executes the image forming operation in the high speed mode.

  Next, the control unit 80 proceeds to step S108, and adds or subtracts the count value based on the change in the conditions (1) to (6) described above.

  Next, the control unit 80 proceeds to step S109 and determines whether there is any remaining image forming job. If “Yes” in step S109, the process returns to step S106. On the other hand, if “No” in step S109, it is determined that the current image forming job is completed, and the process returns to step S104.

  When the process proceeds from step S106 to step S110, the control unit 80 selects the low speed mode, operates the motor 20M at a normal motor speed, and causes the image forming unit 10 to perform an image forming operation. That is, since the count value is 150 or more, the control unit 80 estimates that there is a possibility that the interior 2A of the housing 2 is excessively heated, and forms an image in the low-speed mode in which the heat generated by the motor 20M or the like is reduced. Perform the action.

  Next, the control unit 80 proceeds to step S111, and adds or subtracts the count value based on the change in the conditions (1) to (6) described above.

  Next, the control unit 80 proceeds to step S112 and determines whether or not there is a remaining image forming job. If “Yes” in step S112, the process returns to step S110. On the other hand, if “No” in step S112, it is determined that the current image forming job is completed, and the process returns to step S104.

  When the process proceeds from step S105 illustrated in FIG. 3 to step S113 illustrated in FIG. 4, the control unit 80 shifts the image forming unit 10 from the Ready mode to the Sleep mode.

  Next, the control unit 80 proceeds to step S114 and determines whether or not an image forming job has been received within 5 minutes. If “Yes” in step S114, the process proceeds to step S121. On the other hand, if “No” in step S114, the process proceeds to step S115.

  When the process proceeds from step S114 to step S115, the control unit 80 subtracts the count value. In this embodiment, 3 is subtracted from the count value.

  Next, the control unit 80 proceeds to step S116 and determines whether or not the count value is 78 or more. If “Yes” in step S116, the process proceeds to step S117. On the other hand, if “No” in step S116, the process returns to step S114.

  When the process proceeds from step S116 to step S117, the control unit 80 determines whether an image forming job has arrived within 5 minutes. If “Yes” in step S117, the process proceeds to step S121. On the other hand, if “No” in step S117, the process proceeds to step S118.

  When the process proceeds from step S117 to step S118, the control unit 80 determines whether or not the count value is 87.5 or more. If “Yes” in step S118, the process proceeds to step S119. On the other hand, if “No” in step S118, the process proceeds to step S120.

  When the process proceeds from step S118 to step S119, the control unit 80 subtracts the count value. In this embodiment, 12.5 is subtracted from the count value. Then, the process returns to step S117.

  When the process proceeds from step S118 to step S120, the control unit 80 rewrites the count value to 75 and returns to step S114.

  In short, in steps S114 to S120, the control unit 80 estimates the temperature of the interior 2A of the housing 2 and the decreasing tendency of the temperature in consideration of the duration of the sleep mode and the magnitude of the count value, and subtracts it from the count value. Increase or decrease the value to be. Steps S114 to S120 correspond to the condition (7) described above.

  On the other hand, when the process proceeds from step S114 or step S117 to step S121, the control unit 80 causes the image forming unit 10 to perform a warm-up operation. Thereafter, the process proceeds to step S106 shown in FIG. 3 to process the image forming job.

. The control unit 80 ends the processing shown in FIGS. 3 and 4 when the apparatus power is turned off.

<Power OFF button reception process>
When the control unit 80 starts accepting processing of the power OFF button 95 shown in FIG. 5, first, in step S151, the control unit 80 determines whether or not the power OFF button 95 has been pressed. If “No” in step S151, the process returns to step S151. On the other hand, if “Yes” in step S151, the process proceeds to step S152.

  After shifting from step S151 to step S152, the control unit 80 stores the count value of the counter 87 and the current time in the NVRAM 85. The control unit 80 ends the processing shown in FIG. 5 when the apparatus power is turned off.

<Cooling fan control processing>
When the control process of the cooling fan 70 shown in FIGS. 6 to 9 is started, the control unit 80 first determines in step S201 shown in FIG. 6 whether or not the image forming unit 10 is performing a warm-up operation. If “No” in step S201, the process proceeds to step S203. On the other hand, if “Yes” in step S201, the process proceeds to step S202.

  When the process proceeds from step S201 to step S202, the control unit 80 operates the cooling fan 70 at half speed until the warm-up operation is completed. Thereafter, the control unit 80 returns to step S201.

  When the process proceeds from step S201 to step S203, the control unit 80 determines whether or not the image forming unit 10 is in the sleep mode. If “No” in step S203, the process proceeds to step S205. On the other hand, if “Yes” in step S203, the process proceeds to step S204.

  When the process proceeds from step S203 to step S204, the control unit 80 stops the cooling fan 70 until the sleep mode ends. Thereafter, the control unit 80 returns to step S201.

  When the process proceeds from step S203 to step S205, the control unit 80 determines whether the image forming unit 10 is in the middle of an image forming operation. If “No” in step S205, the process proceeds to step S207. On the other hand, if “Yes” in step S205, the process proceeds to step S206.

  When the process proceeds from step S205 to step S206, the control unit 80 executes a cooling fan control routine during the image forming operation shown in FIG. Thereafter, the control unit 80 returns to step S201 shown in FIG.

  When the process proceeds from step S205 to step S207, the control unit 80 determines whether or not the image forming unit 10 has finished the image forming operation. If “No” in step S207, the process proceeds to step S209. On the other hand, if “Yes” in step S207, the process proceeds to step S208.

  When the process proceeds from step S207 to step S208, the control unit 80 executes a cooling fan control routine accompanying the end of the image forming operation shown in FIG. Thereafter, the control unit 80 returns to step S201 shown in FIG.

  When the process proceeds from step S207 to step S209, the control unit 80 executes a cooling fan control routine in the Ready mode shown in FIG. Thereafter, the control unit 80 returns to step S201 shown in FIG.

<Cooling fan control routine during image forming operation>
When the control unit 80 proceeds to step S206 and starts the cooling fan control routine during the image forming operation shown in FIG. 7, the control unit 80 refers to the count value of the counter 87 stored in the NVRAM 85 in step S211.

  Next, the control unit 80 proceeds to step S212 and determines whether or not the count value is less than 50. If “No” in step S212, the process proceeds to step S214. On the other hand, if “Yes” in step S212, the process proceeds to step S213.

  When the process proceeds from step S212 to step S213, the control unit 80 stops the cooling fan 70 until the image forming unit 10 finishes the image forming operation. Thereafter, the control unit 80 ends the subroutine shown in FIG. 7, and returns to step S201 shown in FIG.

  When the process proceeds from step S212 to step S214, the control unit 80 determines whether the count value is 50 or more and less than 100. If “No” in step S214, the process proceeds to step S216. On the other hand, if “Yes” in step S214, the process proceeds to step S215.

  When the process proceeds from step S214 to step S215, the control unit 80 operates the cooling fan 70 at half speed until the image forming unit 10 finishes the image forming operation. Thereafter, the control unit 80 ends the subroutine shown in FIG. 7, and returns to step S201 shown in FIG.

  When the process proceeds from step S214 to step S216, the control unit 80 operates the cooling fan 70 at full speed until the image forming unit 10 finishes the image forming operation. Thereafter, the control unit 80 ends the subroutine shown in FIG. 7, and returns to step S201 shown in FIG.

<Cooling fan control routine upon completion of image forming operation>
When the control unit 80 proceeds to step S208 and starts the cooling fan control routine accompanying the end of the image forming operation shown in FIG. 8, the control unit 80 refers to the count value of the counter 87 stored in the NVRAM 85 in step S221.

  Next, the control unit 80 proceeds to step S222 and determines whether or not the count value is less than 50. If “No” in step S222, the process proceeds to step S224. On the other hand, if “Yes” in step S222, the process proceeds to step S223.

  When the process proceeds from step S222 to step S223, the control unit 80 stops the cooling fan 70 for 10 seconds after the image forming operation of the image forming unit 10 is completed. Thereafter, the control unit 80 ends the subroutine shown in FIG. 8, and returns to step S201 shown in FIG.

  When the process proceeds from step S222 to step S224, the control unit 80 determines whether the count value is 50 or more and less than 100. If “No” in step S224, the process proceeds to step S226. On the other hand, if “Yes” in step S224, the process proceeds to step S225.

  When the process proceeds from step S224 to step S225, the control unit 80 operates the cooling fan 70 at half speed for 10 seconds after the image forming operation of the image forming unit 10 is completed. Thereafter, the control unit 80 ends the subroutine shown in FIG. 8, and returns to step S201 shown in FIG.

  When the process proceeds from step S224 to step S226, the control unit 80 operates the cooling fan 70 at full speed for 10 seconds after the image forming operation of the image forming unit 10 is completed. Thereafter, the control unit 80 ends the subroutine shown in FIG. 8, and returns to step S201 shown in FIG.

<Cooling fan control routine in Ready mode>
When the control unit 80 proceeds to step S209 and starts the cooling fan control routine in the Ready mode shown in FIG. 9, the control unit 80 refers to the count value of the counter 87 stored in the NVRAM 85 in step S231.

  Next, the control unit 80 proceeds to step S232 and determines whether or not the count value is less than 75. If “No” in step S232, the process proceeds to step S234. On the other hand, if “Yes” in step S232, the process proceeds to step S233.

  When the process proceeds from step S232 to step S233, the control unit 80 stops the cooling fan 70 until the ready mode ends. Thereafter, the control unit 80 ends the subroutine shown in FIG. 9, and returns to step S201 shown in FIG.

  When the process proceeds from step S232 to step S234, the control unit 80 operates the cooling fan 70 at half speed until the ready mode is completed. Thereafter, the control unit 80 ends the subroutine shown in FIG. 9, and returns to step S201 shown in FIG.

  The control unit 80 ends the processes shown in FIGS. 6 to 9 when the apparatus power is turned off.

  Step S211 shown in FIG. 7, step S221 shown in FIG. 8, and step S231 shown in FIG. 9 are examples of the “temperature information acquisition process” of the present invention. Steps S222 to S226 shown in FIG. 8 are an example of the “first control process” in the present invention. Steps S212 to S216 shown in FIG. 7 are an example of the “third control process” in the present invention.

  Regarding the count value of the counter 87, a range of 100 or more is an example of the “high temperature range” of the present invention, and a range of 50 or more and less than 100 is an example of the “low temperature range lower than the high temperature range” of the present invention. The range below is an example of the “range lower than the low temperature range” of the present invention.

<Effect>
In the image forming apparatus 1 of Embodiment 1, the control unit 80 executes a cooling fan control routine during the image forming operation shown in FIG. As a result, when the count value is 100 or more during the image forming operation, the control unit 80 estimates that the temperature of the interior 2A of the housing 2 is in the high temperature range and operates the cooling fan 70 at full speed. When the count value is 50 or more and less than 100, it is estimated that the temperature of the interior 2A of the housing 2 is in the low temperature range, and the cooling fan 70 is operated at half speed. When the count value is less than 50, it is estimated that the temperature of the interior 2A of the housing 2 is lower than the low temperature range, and the cooling fan 70 is stopped.

  Further, in this image forming apparatus 1, the control unit 80 executes a cooling fan control routine accompanying the end of the image forming operation shown in FIG. Thereby, when the count value is 100 or more at the time when the image forming operation is completed, the control unit 80 estimates that the temperature of the interior 2A of the housing 2 is in the high temperature range, and keeps the cooling fan 70 at full speed for 10 seconds. Operate. When the count value is 50 or more and less than 100, it is assumed that the temperature of the interior 2A of the housing 2 is in the low temperature range, and the cooling fan 70 is operated at half speed for 10 seconds. When the count value is less than 50, it is estimated that the temperature of the interior 2A of the housing 2 is lower than the low temperature range, and the cooling fan 70 is stopped for 10 seconds. The 10-second full-speed operation, the 10-second half-speed operation, or the 10-second stop of the cooling fan 70 performed by this routine overlaps with the 10-second period after the Ready mode is started.

  Further, in the image forming apparatus 1, the control unit 80 executes a cooling fan control routine in the Ready mode shown in FIG. Thereby, in the Ready mode, when the count value is 75 or more, the control unit 80 estimates that the interior 2A of the housing 2 needs to be cooled, and operates the cooling fan 70 at half speed. When the count value is less than 75, it is estimated that it is no longer necessary to cool the interior 2A of the housing 2, and the cooling fan 70 is stopped.

  In short, in the image forming apparatus 1, the control unit 80 controls the cooling fan 70 to switch to the full speed operation, the low speed operation, or the stop state based on the count value of the counter 87, so that the image is formed during the image forming operation. It is possible to prevent the cooling fan 70 from operating unnecessarily in the stop state after the formation operation is finished and in the Ready mode.

  Therefore, in the image forming apparatus 1 according to the first exemplary embodiment, it is possible to prevent the user from feeling uncomfortable with the operation sound of the cooling fan 70 and wasteful power consumption. In the image forming apparatus 1, the temperature of the inside 2 </ b> A of the housing 2 can be accurately cooled by the cooling fan 70.

  In the image forming apparatus 1, the temperature information corresponding to the temperature of the inside 2 </ b> A of the housing 2 is the count value of the counter 87. More specifically, the count value of the counter 87 is based on a plurality of conditions relating to the image forming operation that may cause a difference in the temperature of the interior 2A of the housing 2, that is, the change in the above-described conditions (1) to (8). Variable to increase or decrease. Since the image forming apparatus 1 can indirectly estimate the temperature of the interior 2A of the housing 2 based on the count value of the counter 87, a temperature sensor is provided in the interior 2A of the housing 2 so that the temperature of the interior 2A of the housing 2 is increased. There is no need to actually measure the temperature. As a result, in this image forming apparatus 1, the user can feel the operation sound of the cooling fan 70 uncomfortable or the power is wasted while reducing the manufacturing cost by reducing the temperature sensor. Can be suppressed.

(Example 2)
In the image forming apparatus according to the second embodiment, in step S208 in FIG. 6, instead of the cooling fan control routine accompanying the end of the image forming operation shown in FIG. 8, the cooling fan control routine accompanying the end of the image forming operation shown in FIG. Execute. Since the other configuration of the second embodiment is the same as that of the first embodiment, the description thereof is omitted.

  In the image forming apparatus according to the second embodiment, when the control unit 80 starts the control process for the cooling fan 70 illustrated in FIGS. 6 to 9 and proceeds to step S208 illustrated in FIG. 6, the image forming operation illustrated in FIG. The accompanying cooling fan control routine is started.

  Then, the control unit 80 refers to the count value of the counter 87 stored in the NVRAM 85 in step S241.

  Next, the control unit 80 proceeds to step S242 and determines whether or not the count value is less than 50. If “No” in step S242, the process proceeds to step S244. On the other hand, if “Yes” in step S242, the process proceeds to step S243.

  When the process proceeds from step S242 to step S243, the control unit 80 stops the cooling fan 70 immediately after the image forming operation of the image forming unit 10 is completed. Thereafter, the control unit 80 ends the subroutine shown in FIG. 10, and returns to step S201 shown in FIG.

  When the process proceeds from step S242 to step S244, the control unit 80 determines whether the count value is 50 or more and less than 100. If “No” in step S244, the process proceeds to step S246. On the other hand, if “Yes” in step S244, the process proceeds to step S245.

  When the process proceeds from step S244 to step S245, the control unit 80 operates the cooling fan 70 at full speed for 5 seconds after the image forming operation of the image forming unit 10 is completed. Thereafter, the control unit 80 ends the subroutine shown in FIG. 9, and returns to step S201 shown in FIG.

  When the process proceeds from step S244 to step S246, the control unit 80 operates the cooling fan 70 at full speed for 10 seconds after the image forming operation of the image forming unit 10 is completed. Thereafter, the control unit 80 ends the subroutine shown in FIG. 9, and returns to step S201 shown in FIG.

  Step S241 shown in FIG. 9 is also an example of the “temperature information acquisition process” in the present invention. Steps S242 to S246 shown in FIG. 9 are an example of the “second control process” in the present invention. In step S246, 10 seconds for operating the cooling fan 70 at full speed is an example of the “first period” in the present invention. In step S245, 5 seconds for operating the cooling fan 70 at full speed is an example of the “second period shorter than the first period” of the present invention.

  In the image forming apparatus according to the second embodiment having such a configuration, the control unit 80 executes a cooling fan control routine accompanying the end of the image forming operation shown in FIG. Thus, when the count value is 100 or more at the time when the image forming operation is finished, the control unit 80 estimates that the temperature of the inside 2A of the housing 2 is in the high temperature range, and sets the cooling fan 70 in the first period. Operate at full speed for 10 seconds. When the count value is 50 or more and less than 100, it is assumed that the temperature of the interior 2A of the housing 2 is in the low temperature range, and the cooling fan 70 is operated at full speed for the second period of 5 seconds. When the count value is less than 50, it is estimated that the temperature of the interior 2A of the housing 2 is lower than the low temperature range, and the cooling fan 70 is stopped. The 10-second full-speed operation of the cooling fan 70 performed by this routine overlaps with 10 seconds after the Ready mode is started. The full speed operation of the cooling fan 70 performed by this routine for 5 seconds overlaps with 5 seconds after the Ready mode is started.

  In short, in this image forming apparatus, the control unit 80 controls the cooling fan 70 to switch to the full speed operation for 10 seconds, the full speed operation for 5 seconds, or the stopped state based on the count value of the counter 87, thereby performing the image forming operation. It is possible to prevent the cooling fan 70 from operating unnecessarily in the stopped state after the completion.

  Therefore, in the image forming apparatus according to the second embodiment, similarly to the image forming apparatus 1 according to the first embodiment, it is possible to suppress the user from feeling uncomfortable with the operation sound of the cooling fan 70 and wasteful power consumption.

  In the above, the present invention has been described with reference to the first and second embodiments. However, the present invention is not limited to the first and second embodiments, and can be appropriately modified and applied without departing from the spirit of the present invention. Needless to say.

  For example, as a specific example of switching the cooling capacity of the cooling means between a high level and a low level, there may be a change in the opening area of the cooling passage in addition to the change in the rotation speed of the cooling fan 75 shown in the first embodiment.

  In the first control process, one or more intermediate ranges are provided between the high temperature range and the low temperature range, and one or more intermediate levels are set between the high level and the low level. The cooling means may be operated at an intermediate level.

  In the second control process, one or a plurality of intermediate ranges are provided between the high temperature range and the low temperature range, and in the intermediate range, the period for operating the cooling means is shorter than the first period and longer than the second period. May be set.

  The present invention can be used for an image forming apparatus or a multifunction machine.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Housing, SH ... Sheet | seat, 10 ... Image forming part 2A ... Inside of housing, 70 ... Cooling means (cooling fan), 80 ... Control part S211, S221, S231, S241 ... Temperature information acquisition process S222-S226 ... 1st control process, S242-S246 ... 2nd control process S212-S216 ... 3rd control process, 20M ... Drive source (motor)

Claims (8)

A housing;
An image forming unit that is housed in the housing, performs an image forming operation for forming an image on a sheet, and has a heat generating unit that generates heat by the image forming operation;
A cooling means for cooling the inside of the housing, which is provided in the housing and raises the temperature by heat generation of the heat generating portion;
A control unit for controlling the image forming unit and the cooling unit,
The control unit acquires temperature information corresponding to a temperature inside the housing with the end of the image forming operation in the image forming unit;
After determining whether the temperature information acquired by the temperature information acquisition process corresponds to a high temperature range or a low temperature range lower than the high temperature range, and after the image forming unit finishes the image forming operation In a stopped state, a first control that controls the cooling means to operate when the temperature information corresponds to the high temperature range, and does not operate the cooling means when the temperature information corresponds to the low temperature range. And an image forming apparatus. The control unit is controllable to operate the cooling means at a plurality of levels including a high level with a high cooling capacity and a low level with a cooling capacity lower than the high level,
In the first control process, when it is determined that the temperature information corresponds to a high temperature range, the cooling unit is operated at the high level or the cooling unit is operated at the low level according to the level of the temperature information. The image forming apparatus according to claim 1, wherein the image forming apparatus is controlled so as to switch the operation. A housing;
An image forming unit that is housed in the housing, performs an image forming operation for forming an image on a sheet, and has a heat generating unit that generates heat by the image forming operation;
A cooling means for cooling the inside of the housing, which is provided in the housing and raises the temperature by heat generation of the heat generating portion;
A control unit for controlling the image forming unit and the cooling unit,
The control unit acquires temperature information corresponding to the temperature inside the housing 2 with the end of the image forming operation in the image forming unit;
After determining whether the temperature information acquired by the temperature information acquisition process corresponds to a high temperature range or a low temperature range lower than the high temperature range, and after the image forming unit finishes the image forming operation In a stop state, when the temperature information corresponds to the high temperature range, a period for operating the cooling means is set to the first period, and when the temperature information corresponds to the low temperature range, the cooling means is operated. And a second control process for controlling the cooling means to stop after the elapse of the first period or the second period is set to a second period shorter than the first period. An image forming apparatus configured to be configured.   In the second control process, it is further determined whether or not the temperature information acquired by the temperature information acquisition process corresponds to a range lower than the low temperature range, and the image forming unit ends the image forming operation. 4. The image forming apparatus according to claim 3, wherein the cooling unit is controlled not to operate when the temperature information corresponds to a range lower than the low temperature range in the stopped state. The control unit executes the temperature information acquisition process while the image forming unit is performing the image forming operation,
Whether the temperature information acquired by the temperature information acquisition process while the image forming unit is performing the image forming operation corresponds to the high temperature range or the low temperature range. In the state where the image forming unit is performing the image forming operation, when the temperature information corresponds to the high temperature range, the cooling means is operated at a high level with a high cooling capacity, and the temperature information is 2 is configured to further execute a third control process for controlling the cooling means to operate at a low level having a cooling capacity lower than the high level when the temperature corresponds to the low temperature range. The image forming apparatus according to any one of claims 1 to 4.   In the third control process, it is further determined whether or not the temperature information acquired by the temperature information acquisition process while the image forming unit is performing the image forming operation corresponds to a range lower than the low temperature range. 6. The control according to claim 5, wherein when the temperature information corresponds to a range lower than the low temperature range in a state where the image forming unit is performing the image forming operation, the cooling unit is controlled not to operate. Image forming apparatus.   The image according to any one of claims 1 to 6, wherein the temperature information is a variable that increases or decreases based on a change in at least one condition related to the image forming operation that may cause a difference in temperature inside the housing. Forming equipment.   The temperature information includes an interval between the previous image forming operation and the subsequent image forming operation, a size of a sheet on which the image forming operation is performed, and a sheet when the image forming operation is continuously performed on a plurality of sheets. The sheet supply interval when the image forming operation is continuously performed on a plurality of sheets, the operating time of a drive source that drives the image forming unit, whether the image forming operation is a high speed mode or a low speed mode, 8. The variable that increases or decreases based on at least one of an elapsed time from the transition to the sleep mode in which the image forming unit pauses and an elapsed time from when the apparatus power source is turned off to when it is turned on. Image forming apparatus.

Images