JP4095605B2 - Fan control method and apparatus for implementing the same - Google Patents

Description

  The present invention relates to a fan control method and an apparatus for performing the same, and more particularly to a fan control method for improving the accuracy of detecting a failure of a fan for cooling the apparatus and an apparatus for implementing the method, for example, an image forming apparatus for forming an image on a recording medium. It is about.

  A method for detecting a fan failure in a conventional apparatus such as an image forming apparatus will be described.

  Some fans detect whether the impeller (wings) is rotating and output a fan rotation state signal, and others do not. Among these, there are the following prior art examples for detecting a fan failure using the characteristic of outputting a fan rotation state signal.

  When the fan starts to be driven, the fan rotation state signal changes from the non-rotation state to the rotation state after a predetermined time t0 from the start of driving. Here, t0 is a time until it is determined by the fan drive signal that the fan impeller (blade) has started rotating normally, and is a value unique to the fan. The rotation of the fan impeller (wings) is constantly monitored by the fan rotation state signal. If the impeller (wings) stops for some reason during fan operation, the fan rotation state signal is changed from the rotating state. Transition to the non-rotating state.

As a conventional fan failure detection method, it is most common to judge a fan failure when the fan rotation state signal output indicates a non-rotation state continuously for a predetermined time t1 (> t0) during fan operation. Is. As another fan failure detection method, similarly, the fan rotation state signal is used, the first counter is counted up while the fan is driven, and the fan rotation state signal also indicates the non-rotation state during the fan drive. During this period, the second counter is counted up, the first counter value when the first counter reaches a predetermined count value is compared with the second counter value, and the fan failure is judged by the ratio There is also (refer patent document 1).
JP-A-6-255207

  However, in the fan failure detection method as in the conventional example including Patent Document 1, all fan failures occur only in the non-rotation state of the fan rotation state signal regardless of the cause of the fan failure. However, even if the impeller (blade) of the fan does not rotate for some reason, the cause is often easily eliminated or eliminated, and it has an automatic return (fan drive retry sequence) function as a function of the IC that controls the fan. Things are common.

  Therefore, as described above, immediately determining the fan failure only by the non-rotation state of the fan rotation state signal does not effectively use the fan automatic return function, and thus the accuracy of the failure determination is improved. This will lead to an increase in the number of fan failures in the market.

  On the other hand, since the automatic return operation of the fan requires a predetermined time specific to the fan, it is necessary to drive the fan for at least the time required for the automatic return operation in order to use the automatic return function. However, driving the fan for a longer time than necessary when cooling is not necessary not only consumes extra power, but also causes deterioration in image quality such as dust entering the apparatus, particularly in an image forming apparatus. May be a problem.

  Therefore, the present invention minimizes unnecessary power consumption and dust intrusion into the apparatus, and improves the accuracy of failure determination by effectively using the self-recovery operation of the fan. The purpose is to reduce the number of fan failures as much as possible except in the case of failure (state where automatic recovery is impossible).

In order to achieve the above object, a fan control device of the present invention is a fan control device that controls driving of a fan motor that generates an air flow between the inside and outside of the device, and the fan control device should be in a rotating state. in the fan control system having a function of performing an automatic return operation during the first hour when it fan motor is a non-rotating state is detected, the fan motor is in any state of the rotating or non-rotating state a rotation state detecting means for detecting whether, when stopping the fan motor in the drive, wherein when the fan motor is in a non-rotating state, the fan motor only long second time than the first time extended drive and, the fan motor is determined the fan motor to be not in rotation and failure state during the extended drive period, if the fan motor is in rotation during the extended drive period Serial and having a determining failure determining means of the fan motor and the normal state.

The fan control device of the present invention is a fan control device that controls driving of a fan motor that generates an air flow between the inside and outside of the device, and the fan motor that should be in a rotating state is in a non-rotating state. In a fan control device having a function of performing an automatic return operation during a first time when it is detected that the fan motor is in a rotating state that detects whether the fan motor is in a rotating state or a non-rotating state a detection means, a non-rotating state storage means for storing the time of non-rotation state of the fan motor being driven, when stopping the fan motor in the drive, when the fan motor is in a non-rotating state, the second time only extended drive by subtracting the time of non-rotation state stored the fan motor from the first hour to the non-rotating state storage means, the fan motor during the extended drive period If not on the rolling condition the determined fan motor and a fault condition, the fan motor during the extended drive period; and a determining failure determination means for the fan motor if the rotational state to a normal state .
Here, a drive time storage means to store the start time of the fan motor, the failure determining means, when the time of the non-rotating state non-rotating state stored in the storing means is longer than the first hour determines a failure state of the fan motor, if start time stored in the drive time storage means is shorter than the first hour performs extension drive of the second time, stored in the driving time memory means If the activation time is and longer than the first hour the time of non-rotation state non-rotating state stored in the storage means is shorter than the first time determines the fan motor to a normal state.

Further, the failure judging means includes a first counting hand stage that counts up when the fan motor during the driving of the fan motor is in a non-rotating state, the change in rotation the fan motor from a non-rotating state when the said first counter and a first reset means for resetting said second period of time, from said first hour before Symbol the fan motor required for automatic return operation, the at the fan motor stop It is equal to or longer than the time obtained by subtracting the time corresponding to the value indicated by the first counter. Further, the failure determining means, and a second count hand stage of performing count up in the fan motor drive, and a second reset means for resetting said second counter when said fan motor stop, drive the time corresponding to the value indicated by the second counter when stopping the fan motor, the fan motor is equal to or less than the first hour before Symbol required for automatic return operation, and the rotation the fan motor is not in the when in the state, the extended fan motor only the second time by driving the fan motor during the extended drive period the fan motor to be not in rotation, it is determined that a fault condition.

Also, the fan motor control method of the present invention is a fan motor control method for generating an air flow between the inside and outside of the apparatus, and the fan motor that should be in a rotating state is in a non-rotating state. in There controlling method of a fan motor for performing an automatic return operation during the first hour when it is detected, when stopping the fan motor in the drive, either the fan motor is a rotation state or a non-rotation state condition the fan motor and detecting whether there, when the fan motor is in a non-rotating state, a step of simply extending driving longer second time than the fan motor the first hour, during the extended drive period step of determining but the fan motor is determined that the fault condition unless not in rotation, the normal state the fan motor if the fan motor is in rotation during the extended drive period Characterized in that it has a.

Also, the fan motor control method of the present invention is a fan motor control method for generating an air flow between the inside and outside of the apparatus, and the fan motor that should be in a rotating state is in a non-rotating state. In the fan motor control method for performing an automatic return operation during the first time when the fan is detected, when the fan motor being driven is stopped, the fan motor is in a rotating state or a non-rotating state. a step of detecting whether in the steps of storing the non-rotating state of the fan motor time during driving, when the fan motor is in a non-rotating state, the storage the fan motor from the first hour a step of simply extending driven second time by subtracting the time of non-rotation state stored in the step of the fan if the fan motor during the extended driving period does not become in rotation Determines over data and fault conditions, the fan motor during the extended drive period; and a step of determining the fan motor if the rotational state to a normal state.
Here, have a more Engineering for storing an activation time of the fan motor, the determination in the determining step, if the time of non-rotation state of said stored is longer than the first hour of the fan motor with a fault state If the stored start time is shorter than the first time, the second time is extended and the stored start time is longer than the first time and the stored non-rotation time If is shorter than the first hour, it determines the fan motor to a normal state.

  As described above, according to the present invention, the fan can be completely broken down by minimizing unnecessary power consumption and dust intrusion into the apparatus and effectively utilizing the self-recovery operation of the fan. The number of fan failures can be reduced as much as possible except in the case of failure (a state where automatic recovery is impossible).

  That is, according to the present invention, when stopping the fan motor that is being driven, if the rotation state signal indicates a non-rotation state, the fan motor is driven to be extended for a predetermined time, and the rotation is performed during the extended drive period. If the state signal does not indicate the rotation state, it is possible to reduce the number of fan failures by using the fan motor automatic return function by determining that the fan motor is in a failure state.

  In addition, by setting the predetermined time to be longer than the time required by the fan motor for the automatic return means, the fan motor automatic return function is reliably used while the fan motor drive is being extended, and the number of fan failures occurring. Can be reduced.

  In addition, by setting the predetermined time to be equal to or longer than the time required for the fan motor to automatically return means by subtracting the time corresponding to the value indicating the time when the fan motor is stopped, the fan motor drive extension time is minimized, In addition, since the fan motor automatic return function is reliably used, it is possible to reduce the number of fan failures while avoiding unnecessary power consumption.

  Further, when stopping the driving fan motor, the time corresponding to the value indicating the driving of the fan motor is equal to or shorter than the time required by the previous fan motor for the automatic return means, and the rotation state signal indicates the non-rotation state. If it is indicated, the fan motor is extended and driven for a predetermined time, and if the rotation state signal does not indicate a rotation state during the extended drive period, it is determined that the fan motor is in a failure state, and thus extra power consumption In addition, it is possible to reduce the number of fan failures while minimizing the entry of dust into the aircraft.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, description will be made based on a laser beam printer which is an example of an image forming apparatus. However, the present invention is not limited to laser beam printers and image forming apparatuses, and has a fan for cooling the apparatus, and can be applied to many apparatuses in which external dust intrusion by the fan adversely affects the apparatus. They are also included in the present invention.

<Configuration example of laser beam printer to which fan control method of this embodiment is applied>
FIG. 1 is a cross-sectional view showing a configuration of a laser beam printer using an electrophotographic process.

  A laser beam printer main body 101 (hereinafter, main body 101) is connected to a host computer 131 through an interface (or bus) 130, receives commands and data, and controls image formation by a printer engine, and the printer controller. The engine controller 126 controls each part of the printer engine in accordance with an instruction from the 127 via the serial interface 133, and a printer engine that executes printing. Note that the serial interface 133 and the interface (bus) 130 are also used for returning event information such as an operation state and a failure.

  The fan motor 300 according to the present embodiment is provided in a circuit unit such as a printer controller 127 or an engine controller 126 that discharges heat from a power source unit, a motor unit, a drum, and a fixing unit that generate high temperatures, or that needs to maintain a low temperature. It is provided to send cooling air. Also, a state is created in which the inside of the printer has a high pressure from the outside to prevent entry of dust and the like. Therefore, in general, the exhaust fan is disposed in the vicinity of the fixing unit at the top of the printer, and the intake fan is disposed in the vicinity of the power supply unit and the circuit unit at the bottom of the printer. Such an arrangement is not limited and corresponds to the arrangement of the components inside the printer. Furthermore, the arrangement of the components inside the printer is designed in consideration of the air flow.

  In this embodiment, the fan motor 300 is controlled by the engine controller 126. However, the printer controller 127 may control the fan motor 300, or the control may be divided by the fan. In that case, the printer controller 127 performs the control shown in the following flowchart.

  The printer engine of the laser beam printer main body 101 includes a cassette 102 for storing a recording sheet S as a recording medium, a cassette sheet presence / absence sensor 103 for detecting the presence / absence of the recording sheet S in the cassette 102, and a recording sheet S in the cassette 102. A cassette size sensor 104 (consisting of a plurality of microswitches) for detecting the size, a sheet feeding roller 105 for separating and feeding the recording sheets S from the cassette 102 one by one, and sheet feeding by the sheet feeding roller 105 A feed roller 132 is provided for transporting the recorded recording paper S.

  A registration roller pair 106 conveys the recording sheet S conveyed by the feed roller 132 and the intermediate roller 133.

  Reference numeral 107 denotes a laser scanner unit, which emits a laser beam modulated based on an image signal (VDO signal) obtained by developing image information sent from an external device 131, which will be described later, and a laser from the laser unit 113. It comprises a polygon motor 114 that rotates a polygon mirror to scan light onto a photosensitive drum 117, which will be described later, an imaging lens 115 that forms an image of laser light from the polygon mirror on the photosensitive drum 117, and a folding mirror 116. .

  Further, a cartridge 108 that forms a toner image on the recording paper S based on the laser beam from the laser scanner unit 107 is provided downstream in the conveyance direction of the registration roller pair 106. The cartridge 108 has a configuration for forming an image on the recording paper S by an electrophotographic method, and includes a photosensitive drum 117, a primary charging roller 119 for charging the surface of the photosensitive drum 117 to a uniform potential, and laser light. A developing device 120 that develops the electrostatic latent image formed on the surface of the photosensitive drum 117 by toner, and the toner image developed on the photosensitive drum 117 on the recording paper S conveyed by the resist roller pair 106. A transfer roller 121 for applying a voltage having a polarity opposite to that of the toner to the photosensitive drum 117 from the back surface of the recording paper S to be transferred, and a transfer residual toner remaining on the photosensitive drum 117 without being transferred to the recording paper S by the transfer roller 121 It is comprised from the cleaner 122 which collect | recovers. A top sensor 135 serving as a reference timing for image formation and fixing control is provided between the registration roller pair 106 and the transfer roller 121.

  Reference numeral 109 denotes a fixing device that thermally fixes a toner image formed on the recording paper S downstream in the conveyance direction of the cartridge 108. The fixing device 109 is provided inside the fixing film 109a, the pressure roller 109b, and the fixing film 109a and generates heat. A ceramic heater 109c for heating the toner image on the recording paper S and a thermistor 109d for detecting the surface temperature of the ceramic heater 109c are configured.

  A fixing sensor 110 that detects the presence or absence of the recording paper S downstream of the fixing device 109 in the transport direction, a fixing roller 111 that discharges the recording paper S on which the toner image has been fixed by the fixing device 109, and a downstream of the fixing roller 111 in the transport direction. A reversing conveyance unit 200 is provided for discharging the recording paper S from the main body 101 face-up (hereinafter referred to as FU) or face-down (hereinafter referred to as FD).

  The reverse conveyance unit 200 discharges the recording sheet S having the image forming surface facing upward and passed through the fixing device 109 to the stacking tray 112 from point A to point B in the drawing with the image forming surface facing upward. From the point A in the drawing to discharge the recording sheet S having the image forming surface upward and the image forming surface downward. And an FD conveyance path which is a second conveyance path for discharging paper to the stacking tray 112 via point B and point B.

  The reverse conveying unit 200 further includes a merging roller 201 driven by a merging motor 209, a reversing roller 202 driven so as to be normally and reversely rotated by a reversing motor 210, an intermediate roller 203 driven by a paper discharging motor 211, FD / FU switching flapper 212 and FD / FU switching flapper for switching whether the recording sheet S should be discharged to the stacking tray 112 via the discharge roller 204 driven by the motor 211, the FU conveyance path or the FD conveyance path FD / FU switching solenoid 205 for switching the tip position of 212 between a and b in the figure, and a separation solenoid 206 for switching the roller pair constituting the reverse roller 202 from the contact state in c in the figure to the separated state in d in the figure, A A reversing set which is provided downstream of the joining roller 201 on the FD conveyance path from point B to the conveyance direction and detects the presence or absence of the recording sheet S. Sheet discharge sensor 208 for detecting the presence or absence of provided by the recording sheet S in the conveying direction downstream of the intermediate rollers 203 of the FD conveying path at the point B from the support 207, C point are provided.

  The main body 101 further includes a main motor 123.

  The main motor 123 supplies driving force to each part in the main body 101, and includes a paper feed roller 105, a feed roller 132, an intermediate roller 133, a registration roller 106, a photosensitive drum 117, a primary charging roller 119, a transfer roller 121, A driving force is supplied to the fixing device 109, the paper discharge roller 111, and the like.

  Note that the sheet feeding roller 105 and the registration roller pair 106 do not always rotate while the main motor is rotating, but the sheet feeding roller clutch 124 and the registration roller clutch whose ON / OFF state is controlled by an engine controller 126 described later. The state is switched by 125 to a state where the driving force of the main motor 123 is transmitted and a state where it is not transmitted, and the recording paper S is controlled to be conveyed at a desired timing.

<Configuration example of control system to which fan control method of this embodiment is applied>
FIG. 2 is a diagram illustrating a configuration example of a control system to which the fan control method of the present embodiment is applied.

  As described with reference to FIG. 1, the host computer 131 and the printer controller 127 of the printer main body 101 are connected via the input / output interface 127f and receive print commands and print data from the host computer 131. The printer controller 127 may be configured to be separated from the printer main body 101 and to be independent and to control a plurality of printer engines.

  The printer controller 127 includes a CPU 127a for arithmetic control, a ROM 127b that stores programs executed by the CPU 127a and fixed parameters, a RAM 127c that is used as a temporary storage when the CPU 127a executes programs, and local control and failure display of the printer main body 101. A serial interface 127e for connecting the display device 127d and the like used for the above and the engine control 126, and the input / output interface 127f. The ROM 127b stores, for example, a print control program for controlling the entire printer main body 101 and a failure notification program related to the present embodiment. The failure notification program may display a failure on the display 127d, sound an alarm buzzer, transmit failure information to the host computer 131, and display the failure information on the display / operation screen 131a of the host computer 131. The RAM 127c has a failure table for storing failure information related to the present embodiment, and a program load area for loading a program from the host computer 131 or a storage medium (not shown).

  The engine controller 126 includes an arithmetic control CPU 126a, a ROM 126b that stores programs executed by the CPU 126a and fixed parameters, a RAM 126c that is used as a temporary storage when the CPU 126a executes programs, and a signal and power source for controlling the fan motor 300. A driver / receiver 126d for supplying and a serial interface 126e for connecting the printer control 127 are provided. The ROM 126b stores, for example, a T1 table that stores the automatic return time T1 of each fan used in the present embodiment, and a fan control program for controlling the fan motor 300. The RAM 126c is a table of times T2 and T3 for controlling the fan drive time used in the present embodiment, a failure table that holds the failure state of each fan, and a fan control table that stores the drive / stop state of each fan. The drive time timer for measuring the extended drive time of the fan of this embodiment is stored.

  Note that FIG. 2 shows only data and programs related to this embodiment, and other data and programs are not shown in order to avoid complexity. Further, although the storage areas are separated into ROM and RAM, there is no essential difference.

<Configuration Example of Fan Motor Drive Circuit of This Embodiment>
Next, a drive circuit for the fan motor will be described with reference to FIG.

  In FIG. 3, when driving the fan motor 300, the engine controller 126 outputs an “H” level signal to the fan drive signal line 308. As a result, the transistor 302 is turned on, and the transistor 305 is further turned on to supply + 24V power as a drive signal to the drive signal line 309 on the fan motor 300 side. Here, the resistor 301 is a pull-down resistor, and the resistor 304 is a pull-up resistor, both of which are resistors for preventing malfunction of the fan motor. The resistor 303 is a resistor for limiting the current flowing through the transistor 302.

  The rotation state signal line 312 of the fan motor 300 is connected to the collector of the internal transistor 311, and when the fan motor is driven, the “H” level is output to the gate line 310, thereby turning on the transistor 311. As a result, the rotation state signal line 312 is held at the “L” level and is transmitted to the rotation state signal line 313 on the engine controller 126 side via the protective resistor 306. Here, the resistor 307 is a pull-up resistor, and is a resistor for preventing erroneous detection of the rotation state by the engine controller 126. The rotation state is detected by the air volume by the impeller 314 and the voltage of the drive signal line 309, but the detection by the air volume is more reliable.

  The above operation is shown as a timing chart in FIG.

  When the engine controller 126 outputs “H” level to the fan drive signal line 308 in order to drive the fan motor 300, the fan motor 300 changes the rotation state signal from “H” to “L”. At this time, a slight delay occurs with respect to the fan drive signal 308. This is because the impeller (blade) 314 of the fan motor 300 that has received the drive signal rotates and detects that it has rotated normally. This is to change the signal.

  On the other hand, when the fan motor 300 is stopped, since the power supply to the fan motor 300 is cut off as described above, the power supplied to the transistor 311 inside the fan motor 300 is also cut off. The rotation state signal level changes almost simultaneously.

<Example of fan control in the laser beam printer of this embodiment>
An example of fan control in the laser beam printer main body 101 having the above configuration will be described below in accordance with a flowchart of a fan control procedure and a signal change timing chart at that time. In this embodiment, an example in which the engine controller 126 performs fan control according to the flowchart is shown, but the present invention is not limited to this.

(First example of fan control procedure)
The flow of fan failure detection in this embodiment will be described using the flowchart of FIG.

  First, the power source of the main body 101 is turned on in step S501. In step S502, printing is started. In step S503, it is confirmed whether or not there is a drive request for the fan motor 300. In this embodiment, the fan motor is driven only during the printing operation. If there is a drive request for the fan motor 300 in step S503, the engine controller 126 outputs an “H” level signal to the fan motor drive signal line 308 in FIG. 3 in step S504 (hereinafter referred to as “drive the fan motor”). The fan motor 300 is driven.

  Subsequently, when the printing operation is completed in step S505, it is confirmed in step S506 whether there is a fan motor stop request. If there is a fan motor stop request, the engine controller 126 checks the voltage level of the circuit state signal line 313 in FIG. 3 before stopping the fan motor in step S507. Here, in the present embodiment, when the logic shown in FIG. 4 is used, when the voltage level of the circuit state signal line 313 is “L” level (hereinafter referred to as “rotation state”), the fan motor shown in FIG. An “L” level signal is output to the drive signal line 308 (hereinafter referred to as “stop the fan motor”), and the flowchart ends normally in step S513.

  On the other hand, if the voltage level of the circuit state signal line 313 is “H” level (hereinafter referred to as “non-rotation state”) in step S507, the fan motor drive time is extended by T2 [sec] in step S508. . Here, the extension time T2 is longer than the time T1 [sec] required for the self-return operation of the fan motor 300.

  In step S509, the internal counter of the engine controller 126 starts counting the extension time T2. In steps S510 and S511, the rotation state signal is monitored until the extension time reaches T2, and the rotation state is detected until the extension time T2 elapses. If the signal indicates a rotation state even once, the fan motor is stopped in step S512, the normality is stored and notified in step S513, and the process ends. However, if the rotation state signal does not indicate the rotation state before the extended time T2 elapses in step S510 and step S511, the fan motor is stopped in step S514, and the fan motor failure is stored in step S515. Informs and ends.

  In the above example, it is determined that the rotation state is 1 degree, but it may be multiple times for confirmation.

  Timing charts in the respective fan state examples corresponding to the flow of the flowchart described above are shown in FIGS. In this timing chart, the print operation indicates that the “H” level is during printing, and the logic of the fan drive signal and the rotation state signal is the same as described above.

  FIG. 6 is a timing chart during normal operation in which no fan failure has occurred. In this case, a fan stop request is issued together with the end of printing, and the fan drive immediately ends normally.

  FIG. 7 is a timing chart at the time of a fan failure when the rotation state signal indicates a non-rotation state immediately before the fan stops and the rotation state signal remains in the non-rotation state even during fan drive extension. In this case, a fan stop request is issued upon completion of printing, but since it has been detected that the fan is not rotating, the fan drive is extended for a time T2 longer than the automatic return processing time T1, and the recovery by the automatic return processing is performed. Although it waits, since it does not return to a rotation state in time T2, it will complete | finish after reporting a fan failure.

  FIG. 8 is a timing chart when the rotation state signal is restored to the rotation state by the self-returning operation of the fan while the fan drive is being extended, thereby completing the normal end. In this case, a fan stop request is issued upon completion of printing, but since it has been detected that the fan is not rotating, the fan drive is extended for a time T2 longer than the automatic return processing time T1, and the recovery by the automatic return processing is performed. Wait and return to the rotation state. Alternatively, if the fan drive extension is stored as a flag or the number of extensions is stored in association with the fan and a warning is issued under a predetermined condition, the fan is repaired / replaced in the printer stop state immediately before the fan failure occurs. Is more desirable.

(Second example procedure of fan control)
Since this embodiment has the same configuration as that of the first procedure example and only the extension time of the fan motor 300 is different, only the flowcharts of FIGS. 9 and 10 will be described. The description of the same processing steps as those in FIG. 5 is omitted.

  In the present embodiment, the flowcharts of FIGS. 9 and 10 are simultaneously moving in parallel. In FIG. 9, the difference from FIG. 5 is only the fan drive extension time T3 in steps S608 and S610. This extension time T3 reflects the result of the flowchart of FIG. 10 that moves in parallel. In the first example procedure, the extension drive was fixed for a fixed T2 time, but the non-rotating state was entered. The drive extension time is shortened by the time corresponding to the number of times (T3 = T1-failure counter time).

  The following is a description of FIG. FIG. 10 is a flowchart for constantly monitoring the rotation state signal.

  First, when the power of the main body 101 is turned on in step S701 and the fan motor 300 is driven in step S702, the rotation state signal starts to be monitored in step S703.

  If the fan motor 300 is stopped in step S702 or if the rotation state signal indicates a rotation state in step S703, the failure counter is reset in step S704. On the other hand, if the fan motor 300 is being driven in step S702 and the rotation state signal indicates a non-rotation state in step S703, the failure counter is incremented in step S705.

  In the flowchart of FIG. 10, the rotation state signal is monitored at a constant cycle. Here, the counter value of the failure counter is converted into the time during which the rotation state signal is in the non-rotation state, and step S608 in FIG. Is used to calculate the extended drive time T3 of the fan motor 300.

  FIG. 11 and FIG. 12 show timing charts in each fan state example corresponding to the flow of the flowchart described above. The logic of each signal in this timing chart is the same as in the first procedure example.

  FIG. 11 is a timing chart when the rotation state signal indicates a non-rotation state during fan driving, and the rotation state signal remains in the non-rotation state even during fan drive extension. In this case, a fan stop request is issued at the end of printing, but since it is detected that the fan is not rotating, T3 time obtained by subtracting the time corresponding to the count of the number of fan stops during this time from the automatic return processing time T1, The drive of the fan is extended to wait for the return by the automatic return process, but since it does not return to the rotating state during T3 time, the fan failure is notified and the process ends.

  FIG. 12 is a timing chart when the rotation state signal is restored to the rotation state by the self-returning operation of the fan while the fan drive is being extended, thereby completing the normal end. In this case, a fan stop request is issued at the end of printing, but since it is detected that the fan is not rotating, T3 time obtained by subtracting the time corresponding to the count of the number of fan stops during this time from the automatic return processing time T1, The operation of the fan is extended for a period of time, waiting for a return by the automatic return process, and it returns to the rotating state, so it ends normally. Alternatively, if the fan drive extension is stored as a flag or the number of extensions is stored in association with the fan and a warning is issued under a predetermined condition, the fan is repaired / replaced in the printer stop state immediately before the fan failure occurs. Is more desirable.

(Third example of fan control)
Since the present embodiment has the same configuration as the first and second procedure examples and only the extension time of the fan motor 300 is different, only the flowcharts of FIGS. 13 and 14 will be described. Note that description of the same processing steps as those in FIGS. 9 and 10 is omitted.

  In the present embodiment, the flowcharts of FIGS. 13 and 14 are simultaneously moved in parallel. In FIG. 13, the difference from FIG. 9 is that the internal counter of the engine controller 126 is counted up in order to measure the time during which the fan motor is driven in step S805. When the fan motor is stopped, this driving is performed in step S809. A comparison is made as to whether or not the value of the intermediate counter is equal to or greater than the time T1 [sec] required for the automatic return operation of the fan motor. If the value is greater than T1, the fan motor 300 is stopped in step S815 regardless of the rotation state signal. In FIG. 13, when the fan motor drive time is equal to or longer than T1, the fan motor failure detection is performed in FIG. 14 instead of checking the rotation state signal when the fan motor is stopped.

  FIG. 14 is a flowchart for monitoring the rotation state signal. As in FIG. 10, the time during which the rotation state signal indicates the non-rotation state is counted in step S905. The difference from FIG. 10 is whether or not the value of the failure counter is greater than or equal to T1 [sec] in step S906. If it is determined that the non-rotation state has continued for T1 or more, a fan motor failure is detected in step S907.

  FIG. 15 and FIG. 16 show timing charts in each fan state example corresponding to the flow of the flowchart described above. The logic of each signal in this timing chart is the same as in the first and second procedure examples.

  FIG. 15 assumes that continuous printing is in progress, and the fan drive time is T1 or more. Here, it is a timing chart when the rotation state signal indicates a non-rotation state of T1 or more during fan driving. The process proceeds from step S906 in FIG. 14 to S907, and a fan failure occurs. In step S807 in FIG. 13, a failure occurs, and the fan failure is notified.

  FIG. 16 is also a timing chart in the case where the fan driving time is T1 or more and the rotation state signal when the fan is stopped indicates a non-rotation state. Here, since the failure time is less than T1 and the drive time is T1 or more, the process ends normally.

1 is a diagram illustrating a configuration example of an image forming apparatus according to an embodiment. It is a figure which shows the structural example of the fan control system which concerns on this embodiment. It is a figure explaining the drive circuit of the fan motor which concerns on this embodiment. It is a timing chart at the time of the drive of the fan motor which concerns on this embodiment. It is a flowchart which concerns on the 1st example of a procedure of the fan control of this embodiment. It is a timing chart of the fan normal example in the 1st example of a procedure of this embodiment. It is a timing chart of the fan failure example in the 1st example of a procedure of this embodiment. It is a timing chart of the fan return example in the 1st example of a procedure of this embodiment. This embodiment is also a flowchart according to a second procedure example of fan control. This embodiment is also a flowchart according to a second procedure example of fan control. It is a timing chart of the fan failure example in the 2nd procedure example of this embodiment. It is a timing chart of the example of fan restoration in the 2nd example of a procedure of this embodiment. This embodiment is also a flowchart according to a third procedure example of fan control. This embodiment is also a flowchart according to a third procedure example of fan control. It is a timing chart of the fan failure example in the 3rd procedure example of this embodiment. It is a timing chart of the fan normal example in the 3rd procedure example of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Image forming apparatus main body 126 Engine controller 127 Printer controller 131 Host computer 300 Fan motor 308 Fan drive signal line 313 Rotation state signal line

Claims (8)

A fan control device that controls driving of a fan motor that generates an air flow between the inside and outside of the device, and that is detected when the fan motor that should be in a rotating state is detected to be in a non-rotating state. In a fan control device having a function of performing an automatic return operation during one hour ,
A rotation state detecting means the fan motor to detect whether the one of the state of rotation or non-rotation state,
When stopping the fan motor in the drive, the fan motor when said fan motor is in a non-rotating state, the fan motor was only extended drive longer second time than the first hour, during the extended drive period and wherein the but to have said fan motor is determined failure determining means of the fan motor if the rotational state to a normal state the fan motor to be not in rotation is determined that a fault state, during the extended drive period Fan control device. A fan control device that controls driving of a fan motor that generates an air flow between the inside and outside of the device, and that is detected when the fan motor that should be in a rotating state is detected to be in a non-rotating state. In a fan control device having a function of performing an automatic return operation during one hour,
Rotation state detection means for detecting whether the fan motor is in a rotating state or a non-rotating state;
A non-rotating state storage means for storing the non-rotating state of the fan motor time during driving,
When stopping the fan motor being driven, if the fan motor is in a non-rotating state, the non-rotating state time stored in the non-rotating state storage means is subtracted from the first time for the fan motor . The drive is extended for a second time, and if the fan motor does not rotate during the extended drive period, the fan motor is determined to be in a failed state, and if the fan motor is rotated during the extended drive period, the fan motor A fan control device comprising failure determination means for determining a normal state . A drive time storage means to store the start time of the fan motor,
It said failure determining means, the case where the time of non-rotation state stored in the non-rotating state storage means is longer than the first time, it is determined that the fault condition of the fan motor, which is stored in the driving time memory means start When the time is shorter than the first time, the second time is extended and the start-up time stored in the drive time storage means is longer than the first time and stored in the non -rotation state storage means. 3. The fan control device according to claim 2 , wherein when the time of the rotation state is shorter than the first time, the fan motor is determined to be in a normal state. The failure determination means includes
A first count hand stage that counts up when the fan motor during the driving of the fan motor is in a non-rotating state,
First reset means for resetting the first counter when the fan motor changes from a non-rotating state to a rotating state;
The second hour, wherein the first hour before Symbol required for the fan motor is automatic return operation is the fan motor when stopping the first counter value corresponding to the time over which minus the time indicated by the The fan control device according to claim 2 . The failure determination means includes
A second counting hand stage of performing count up in the fan motor drive,
And a second reset means for resetting said second counter when said fan motor stop,
Time corresponding to the value indicated by the second counter when stopping the fan motor in the drive, the fan motor is equal to or less than the first hour before Symbol required for automatic return operation, and the fan motor is not when in the rotating state, the fan motor is driven by extended by the second time, the fan motor when the fan motor during the extended driving period does not become a rotational state is characterized by determining a fault condition The fan control device according to claim 2 . A method of controlling a fan motor that generates an air flow between inside and outside the apparatus, wherein the fan motor that should be in a rotating state is detected to be in a non-rotating state during a first time. In the control method of the fan motor that performs the automatic return operation,
When stopping the fan motor in the drive, the steps of the fan motor to detect whether the one of the state of rotation or non-rotation state,
When the fan motor is in a non-rotating state, a step of simply extending driving longer second time than the fan motor the first hour,
The fan motor is determined the fan motor to be not in rotation and failure state during the extended drive period, and the fan motor is determined the fan motor if the rotational state to a normal state process during prolonged driving period A method for controlling a fan motor, comprising: A method of controlling a fan motor that generates an air flow between inside and outside the apparatus, wherein the fan motor that should be in a rotating state is detected to be in a non-rotating state during a first time. In the control method of the fan motor that performs the automatic return operation,
Detecting whether the fan motor is in a rotating state or a non-rotating state when stopping the driving fan motor;
A step of storing the non-rotating state of the fan motor time during driving,
When the fan motor is in a non-rotating state, extending the fan motor by a second time obtained by subtracting the non-rotating state time stored in the storing step from the first time ;
Determining that the fan motor is in a failed state if the fan motor does not rotate during the extended drive period, and determining that the fan motor is in a normal state if the fan motor is rotated during the extended drive period; A method for controlling a fan motor, comprising: Has a more Engineering for storing an activation time of the fan motor,
Wherein in the determining step, if the time of non-rotation state of said stored is longer than the first time, it is determined that the fault condition of the fan motor, if the stored start time is shorter than the first hour the performs extension drive of the second time, determining if the stored activation time of the time a non-rotating state of being longer than and the storage the first time is shorter than the first hour, the fan motor to a normal state The fan motor control method according to claim 7 , wherein:

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